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ABSTRACT Aim Materials and Methods Results Conclusion To evaluate long‐term survival and success of dental implants and evaluate indicators affecting the long‐term outcome.Implant survival, success and crestal bone loss (BL) over time were evaluated. For covariates at patient level, Kaplan–Meier estimates of implant survival were compared between groups with the log‐rank test. Observed mean bone loss (MBL) was plotted as a function of time. Cumulative frequencies of BL were plotted for different post‐op times. Uni‐ and multivariate analysis was performed. Simple linear mixed and multiple linear mixed models for BL at 1, 5 and 10 years were fitted.407 patients (221 women, 186 men; mean age 64.86 years (range 28–92, SD 10.11)), with 1482 implants, responded. Absolute implant survival was 94.74%; MBL was 0.81 mm (SD 1.58, range 0.00–17.00) after an average follow‐up of 10.66 years (range 10–14, SD 0.87). Implant survival was influenced on implant level by smoking, implant width and early bone loss (EBL) > 0.5 mm; on patient level by a history of periodontitis. Indicators influencing MBL after the 1st year were abutment height, type of surgery and implant width, while after 5 and 10 years of function were abutment height, EBL > 0.5 mm and smoking.Implant survival was significantly affected by a history of periodontitis on patient level and by smoking, implant width and EBL > 0.5 mm on implant level. Late bone loss was significantly affected by abutment height, EBL > 0.5 mm and smoking.Trial Registration: B670201524796 [ABSTRACT FROM AUTHOR]

Objectives: To test the reliability of full zirconia implant‐supported fixed dental prostheses with cantilever extension (FDPCs) after at least 1 year of function. Materials and Methods: Thirty‐five patients in need of implant‐supported single unit crowns (SUC) and FDPCs in posterior areas were enrolled. After implant placement, patients were rehabilitated with screw‐retained full‐zirconia FDPCs. Implant survival rate, pocket probing depth (PPD), presence/absence of bleeding on probing (BoP), and presence/absence of mechanical/technical complications were recorded. Mesial and distal radiographic marginal bone levels (mBLs) from baseline (i.e., recall appointment 3–6 months after implant loading [T0]) to the follow‐up examination (i.e., latest recall appointment after at least 12 months after T0 [T1]), were calculated. Results: Thirty patients with 34 FDPCs (31 SUCs and 3 FDPs) supported by 37 implants were available for analysis after a mean loading time of 2.6 ± 1.5 years (range: 13–87 months). No implants were lost. MBLs and mean PPD values did not change statistically significantly from T0 to T1 from 0.92 mm ± 0.42 to 0.96 mm ± 0.38 (95% CI: −0.07/0.17; p =.418) and from 2.99 mm ± 0.70 to 3.27 mm ± 0.71 (95% CI: −0.11/0.68; p =.25) respectively. Peri‐implant mucositis was diagnosed in 22 cases. Screw‐loosening and zirconia chipping occurred 1× in 4 patients. Conclusion: Within the limitations of the present proof‐of‐principle study, the use of full‐zirconia FDPCs in posterior areas seems a valid and safe short‐term treatment option. [ABSTRACT FROM AUTHOR]

Aim: To compare mean bone level (mBL) changes around dental implants with one or two adjacent teeth after a function time of ≥10 years. Materials and Methods: One hundred thirty three periodontally compromised patients (PCPs) with 551 implants enrolled in supportive periodontal care (SPC) were screened. Implants were categorized either into group TIT (tooth‐implant‐tooth) or into group TIG (tooth‐implant‐gap). MBL changes from delivery of restoration (i.e., baseline) to follow‐up were calculated in millimeters and compared between implants and adjacent teeth. Survival rates and the need for surgical interventions during SPC were recorded. Results: Eighty seven patients with 142 implants were re‐evaluated after a mean observation time of 14.5 ± 3.5 years. The mBL at mesial implant sites in the TIT group increased −0.07 ± 0.92 mm and decreased in the TIG group 0.52 ± 1.34 mm, respectively (95% CI: 0.04/1.14, p =.037). At distal implant sites, the mBL in the TIT group increased −0.08 ± 0.84 mm and decreased 0.03 ± 0.87 in the TIG group, respectively (95% CI: −0.20/0.42, p =.48). The overall implant loss rate was 3.5% (n = 5; 2 TIT, 3 TIG), without a statistically significant difference between the two groups (95% CI: 0.18/7.07, p =.892). Tooth loss rates (TIT: 12.3%, TIG: 12.3%) were not statistically significantly different (OR = 1.00, p =.989). Conclusion: High tooth and implant survival rates were observed in PCPs. The presence of one or two adjacent teeth seemed to have no impact on marginal bone level changes. [ABSTRACT FROM AUTHOR]

Objectives: To analyse the long‐term effect of plaque formation on implant abutments with an antibacterial coating and the ensuing host response in peri‐implant tissues. Materials and methods: Four implants were installed in each mandibular premolar region following tooth extraction in six dogs. Three months later, two test abutments with a titanium–bismuth–gallium (Ti‐Bi‐Ga) coating and two control titanium abutments were connected to the implants on each side of the mandible. After 2 months, ligatures were placed around the implants in one side of the mandible and plaque formation was allowed until the end of the experiment. The ligatures were removed after 4 weeks. Radiographs and microbiological samples were obtained from each implant site during the plaque formation period. Biopsies were obtained 8 months after abutment connection and prepared for histological analysis. Results: The analysis did not reveal any statistically significant differences in bone loss, bacterial growth and size of inflammatory lesions between implant units with and without the Ti‐Bi‐Ga coating. Implant sites exposed to the short period of ligature‐induced breakdown demonstrated more pronounced bone loss and bacterial growth than non‐ligature sites. Conclusions: It is suggested that a Ti‐Bi‐Ga coating does not prevent biofilm formation on the implant device and does not influence the ensuing host response in the adjacent peri‐implant mucosa. [ABSTRACT FROM AUTHOR]

Objectives: To analyse whether there is a difference in marginal bone levels (MBL) and the respective changes between cemented and screw‐retained reconstructions at 3 and 5 years of loading. Methods: Radiographic data from 14 prospective multicentre clinical trials following implant loading with fixed cemented (CEM) or screw‐retained (SCREW) reconstructions with a 3‐ to 5‐year follow‐up were retrieved from a database. MBL and MBL changes were assessed at initiation of implant loading (BL), at 3 (FU‐3) and 5 years (FU‐5) thereafter. The presence of peri‐implantitis was also determined. Results: Data from 1,672 implants at BL, 1,565 implants at FU‐3 and 1,109 implants at FU‐5 were available. The mean MBL amounted to 0.57 mm (SD 0.87) at BL, 0.55 mm (SD 0.86) at FU‐3 and 0.65 mm (SD 1.18) at FU‐5. At FU‐3, the mean MBL was 0.44 mm (SD 0.65) in group CEM and 0.63 mm (SD 0.99) in group SCREW showing a significant difference between the groups (intergroup <0.05). At FU‐5, the mean MBL was 0.42 mm (SD 0.77) in CEM and 0.80 mm (SD 1.37) in SCREW, again with significant differences between both groups (p <.05). MBL changes between BL and FU‐3 amounted to 0.11 mm (SD 1.02) (bone loss) in SCREW and −0.17 mm (SD 1.03) (bone gain) in CEM. Similarly, mean MBL changes from BL to FU‐5 amounted to 0.23 mm (SD 1.31) (bone loss) in SCREW and −0.26 mm (SD 1.27) (bone gain) in CEM. The prevalence of peri‐implantitis amounted to 6.9% in CEM and 5.6% in group SCREW (intergroup p =.29063) at FU‐3. At FU‐5, peri‐implantitis amounted to 4.6% in CEM and 6.2% in group SCREW (intergroup p =.28242). Conclusion: Cemented implant reconstructions compared with screw‐retained reconstructions revealed higher marginal bone levels and similar rates of peri‐implantitis during 5 years. The difference in MBL and the respective changes between the two groups, however, appear to be clinically negligible. [ABSTRACT FROM AUTHOR]

Aim: To report the clinical and radiographic outcomes of implant-supported fixed dental prostheses with cantilever extensions (FDPCs) after a function time ≥10 years. Material and methods: Patients with FDPCs in posterior areas were clinically and radiographically re-evaluated. Mesial and distal radiographic marginal bone levels (mBLs) from baseline (i.e. delivery of FDPC) to the follow-up examination were calculated and compared between implant surfaces adjacent to and distant from the cantilever extension. Implant survival rate, pocket probing depth (PPD), presence/absence of bleeding on probing (BoP) and presence/absence of mechanical/technical and biological complications were recorded. Results: Twenty-six patients with 30 FDPCs supported by 60 implants were reevaluated after a mean loading time of 13.3 ± 2.7 years (range: 10-18.6 years). One diameter-reduced implant carrying a cantilever extension fractured, yielding a patientbased survival rate of 96.2% (95% CI: 0.95/1.0). The mean marginal bone level change was not statistically significantly different from baseline to follow-up (1.2 mm ± 0.9 to 1.6 mm ± 1.7; 95% CI: -0.1/0.9; p > .05). The mean PPD changed statistically significantly from 3.4 mm ± 0.7 to 3.7 mm ± 0.7 (95% CI: 0.04/0.6; p = .02). Loss of retention occurred ≥ 1x in 9 patients (34.6%, 95% CI: 0.44/0.83). At follow-up, periimplant health was diagnosed in 12 (46.2%), peri-implant mucositis in 7 (26.9%) and peri-implantitis in 7 (26.9%) patients, respectively. Conclusion: Despite a high rate of loss of retention, the use of implant-supported FDPCs in posterior areas represents a reliable long-term treatment option with a high implant survival rate and minimal peri-implant bone level changes irrespective of the location of the cantilever extension. [ABSTRACT FROM AUTHOR]

Objectives: This randomized clinical trial analyzed the long‐term (5‐year) crestal bone changes and soft tissue dimensions surrounding implants with an internal tapered connection placed in the anterior mandibular region at different depths (equi‐ and subcrestal). Materials and methods: Eleven edentulous patients were randomly divided in a split‐mouth design: 28 equicrestal implants (G1) and 27 subcrestal (1–3 mm) implants (G2). Five implants were placed per patient. All implants were immediately loaded. Standardized intraoral radiographs were used to evaluate crestal bone (CB) changes. Patients were assessed immediately, 4, 8, and 60 months after implant placement. The correlation between vertical mucosal thickness (VMT) and soft tissue recession was analyzed. Sub‐group analysis was also performed to evaluate the correlation between VMT and CB loss. Rank‐based ANOVA was used for comparison between groups (α =.05). Results: Fifty‐five implants (G1 = 28 and G2 = 27) were assessed. Implant and prosthetic survival rate were 100%. Subcrestal positioning resulted in less CB loss (−0.80 mm) when compared to equicrestal position (−0.99 mm), although the difference was not statistically significant (p >.05). Significant CB loss was found within the G1 and G2 groups at two different measurement times (T4 and T60) (p <.05). Implant placement depths and VMT had no effect on soft tissue recession (p >.05). Conclusions: There was no statistically significant difference in CB changes between subcrestal and equicrestal implant positioning; however, subcrestal position resulted in higher bone levels. Neither mucosal recession nor vertical mucosa thickness was influenced by different implant placement depths. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this critical review was to evaluate whether commonly used biologic diagnostic parameters correspond to implant survival and peri‐implantitis prevalence. Materials and methods: Publications from 2011 to 2017 were selected by an electronic search using the Pubmed database of the US National Library of Medicine. Prospective and retrospective studies with a mean follow‐up time of at least 5 years and reporting prevalence of peri‐implantitis as well as mean bone loss and standard deviation were selected. The correlation between reported prevalence of peri‐implantitis and reported implant survival, mean follow‐up time, mean bone loss, mean probing depth, and mean bleeding on probing was calculated. Mean bone loss and standard deviation were used for estimation of proportion of implants with bone loss exceeding 1, 2, and 3 mm. Results: Full‐text analysis was performed for 255 papers from 4,173 available ones, and 41 met all the inclusion criteria. The overall mean weighted survival rate was 96.9% (89.9%–100%) and the reported prevalence of peri‐implantitis ranged between 0% and 39.7%, based on 15 different case definitions. The overall weighted bone loss was 1.1 mm based on 8,182 implants and an average mean loading time ranging from 5 to 20 years. No correlation was found between mean bone loss and the reported prevalence of peri‐implantitis. The estimated prevalence of implants with bone loss above 2 mm was 23%. The overall weighted mean probing depth was 3.3 mm, and mean weighted bleeding was 52.2%. Only a weak correlation was found between survival and function time (r = −0.49). There was no relation between the probing depth or bleeding and the mean bone loss, mean follow‐up time, and reported prevalence of peri‐implantitis. Conclusion: Biologic parameters mean probing depth and mean bleeding on probing do not correlate with mean bone loss and this irrespective of follow‐up. Case definition for peri‐implantitis varied significantly between studies indicating that an unambiguous definition based on a specified threshold for bone loss is not agreed upon in the literature. [ABSTRACT FROM AUTHOR]

Abstract: Objective: This report is a 20‐year follow‐up of a randomized controlled clinical trial evaluating the potential long‐term effect of a modified implant surface on the preservation of the peri‐implant marginal bone level. Material & Methods: In each of 51 patients and for each fixed partial denture (FPD), by randomization at least one implant installed had a non‐modified turned surface and one a modified and roughened surface (TiOblast®). Clinical and radiological examinations were performed at various follow‐up intervals. Primary outcome variables were peri‐implant marginal bone level change from time of loading and proportion of implants with no bone loss at 20 years. Multilevel analysis followed by nonparametric and Pearson's Chi‐Square tests were applied for statistical analysis. Results: At the 20‐year follow‐up, 25 patients carrying 64 implants were available for evaluation. Turned and TiOblast implants presented with a mean bone level change from the time of FDP delivery amounting to −0.41 mm (95% CI −0.84/0.02) and −0.83 mm (95% CI −1.38/−0.28) respectively (inter‐group comparison p > .05). 47% of the Turned and 34% TiOblast implants (p > .05) showed no bone loss. All but one of these implants were free of bacterial plaque and inflammation as well as presented with probing pocket depths ≤5 mm at both the 5‐ and 20‐year follow‐up examinations. Conclusion: It is suggested that a moderate increase of implant surface roughness has no beneficial effect on long‐term preservation of the peri‐implant marginal bone level. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: To evaluate the changes in marginal bone levels (MBL) and soft tissue dimension around platform‐switched implants with the implant–abutment junction (IAJ) placed at the crest or 1.5–2 mm subcrestally. Materials and methods: In all, 96 platform‐switched implants were placed in either the posterior maxilla or mandible in 48 partially edentulous patients in a split‐mouth study. All implants were provisionally restored after 4–5 months and definitively after 6 months (T6). Radiographic assessment of MBL was assessed at implant placement (T0), T6, 12 months (T12), and 18 months (T18) after placement. Mid‐buccal soft tissue and papilla measurements were performed at T6, T12, and T18. Results: In all, 43 patients with 86 implants completed the study. The T18 examination showed an implant survival rate of 100% in both groups. Analysis showed that MBL varied as a function of IAJ location, which indicated more coronal bone levels with subcrestal (2.39 ± 0.08 mm) than with epicrestal placements (0.88 ± 0.08 mm) (p < .05). Greater average marginal bone loss was found in the subcrestal group (0.40 ± 0.07 mm) compared to the epicrestal group (0.13 ± 0.08 mm) although no statistically significant difference was found at T18 (p > .05). Levels of mid‐buccal soft tissue had no significant changes over time, regardless of group (p > .05). There was a significant difference in increase in papilla between T6 and T12 and T18 (p = .005 and .001), but not between T12 and T18 (p = .61). These papilla levels and changes were similar between groups (p > .05). Conclusions: The MBL changes around platform‐switched implants with same geometry were not affected by the epicrestal or subcrestal location of the IAJ. Furthermore, the location of the IAJ did not affect the implant survival and soft tissue dimensions. However, no bone loss was located apical to the IAJ when the implants were placed subcrestally. [ABSTRACT FROM AUTHOR]

Objective The aim of the present 36-month prospective split-mouth clinical trial was to investigate the peri-implant soft tissue changes and crestal bone loss (CBL) around delayed loaded platform-switched implants placed at crestal and subcrestal levels. Material and methods Twenty-three individuals with bilaterally missing either mandibular first or second molars were included. The test and control sites were defined as follows: (i) test sites: implants placed 2 mm below the alveolar crest (subcrestal); (ii) control sites: implants placed at bone level (crestal). Forty-six implants (23 implants in test sites and 23 in control sites) were placed in the center of the healed alveolar ridge in the posterior mandible. Peri-implant bleeding on probing (BOP), probing depth (PD ≥ 4 mm), and CBL was compared at 6, 18, and 36 months of follow-up. P < 0.05 was considered statistically significant. Results Sixteen males and seven females with a mean age of 43.5 years (29-50) were included. In the control group ( n = 23), the highest mean percentage of sites that showed BOP and PD ≥ 4 mm were at 6 months (7.4% and 1.4%, respectively). In the test group ( n = 23), the highest mean percentage of sites that showed BOP and PD ≥ 4 mm were at 6 months (2.4% and 1.2%, respectively). The total amount of CBL around crestal and subcrestal implants after 36 months of loading was 0.45 ± 0.2 and 0.3 ± 0.2 mm, respectively. At all follow-up intervals, all intragroup and intergroup comparisons showed no significant differences in BOP, PD ≥ 4 mm, and CBL around implants placed at crestal and subcrestal levels. Conclusion Up to 36 months of follow-up, soft tissue parameters and crestal bone levels can remain equally stable around dental implants placed at crestal and subcrestal levels. The need for long-term follow-up clinical trials is also emphasized. [ABSTRACT FROM AUTHOR]

Objective To evaluate the accuracy between the intra-surgical and the peri-apical radiographic measurements of bone loss at implant with peri-implantitis. Materials and methods A total of 46 Brånemark implants in 24 patients with diagnosis of peri-implantitis were included in the study. The amount of peri-implant bone loss occurred at those implants was measured during peri-implant surgery and compared to the radiographic bone loss measured by three independent examiners. Results The mean bone loss measured on radiographs underestimated the intra-surgical bone loss at the correspondent sites (0.7 mm at the mesial and 0.6 mm at the distal sites); this underestimation was found to be a consistent finding in all the three examiners. Only 21% of the radiographic measurements corresponded to the clinical bone loss assessments, while an over- and underestimation within a range of ± 1-2 mm was recorded in 57% of the cases. There was a moderate positive linear correlation between the radiographic measurements and the clinical bone loss for mesial and distal sites ( r = range 0.58-0.65). The variability between the three examiners in the radiographic measurements was frequently on the range of ± 1-2 mm. Conclusion The radiographic measurements of bone loss at implant affected by peri-implantitis often underestimated the clinical bone loss occurred at the implants. A difference of about ± 1-2 mm in the estimation of radiographic bone loss could be merely assigned as inter-examiner different assessments. [ABSTRACT FROM AUTHOR]

Objectives The aims of the present cross-sectional study are to evaluate the bone remodeling around Morse-cone implants placed subcrestally 1 year after loading and the prevalence of bone loss >0.5 mm after at least 3 years of loading. Material and methods Subjects who underwent a radiographic check in 2013 with implants that had been in function for at least 3 years were considered for inclusion. The study population comprised of 145 subjects with a total of 523 implants. At the moment of insertion, all the implants were placed subcrestally from 1 to 3 mm as clinically measured. Radiographs taken at baseline, that is 1 year after loading ( T0), and at the follow-up visit in 2013 ( T1) were examined. The distance between the rim of the implant and the marginal bone level at mesial and distal aspects of each implant was determined and the mean bone loss calculated. Results In the total sample, the mean bone loss occurred between baseline and 2013 examination was 0.42 ± 0.77 mm; at T1 424 implants presented the marginal bone level at the implant rim (78) or above it (346). On the other hand, 99 implants presented the rim above the bone crest. Fifty-one implants that at T1 presented the rim above the bone crest, and that between T0 and T1 had lost at least 0.5 mm, were considered losers: 10 implants lost up to 0.5 mm, 11 lost from 0.6 to 1 mm, 16 lost from 1.1 to 2 mm, and 14 lost more than 2 mm of bone. On a subject basis, 34 subjects (group A) with a total of 200 implant sites presented loser implants, while 111 subjects (group B) with 323 implants displayed non-loser implants. Conclusions Within the limits of a cross-sectional study, the results show that Morse-cone implants placed subcrestally in the vast majority of cases (89.9%) are able to maintain the bone crest at level of the rim or above it 1 year after loading. The incidence of loser sites (bone loss >0.5 mm) after at least 3 years of follow-up is 9.7% at implant level and 23.5% at patient level. [ABSTRACT FROM AUTHOR]

Objective The purpose of the present 24-month follow-up longitudinal study was to compare the clinical and radiographic status of platform-switched implants placed in patients with and without type 2 diabetes mellitus (T2 DM). Material and methods In total, 45 male non-smokers were included. In Group-1, there were 23 patients with T2 DM, and patients in Group-2 comprised of 22 self-reported non-diabetic controls. Under local anesthesia, platform-switched implants were placed in the mandible. Peri-implant bleeding on probing ( BOP), probing depth ( PD), marginal bone loss ( MBL) and hemoglobin A1c (HbA1c) levels were measured at 12 and 24 months of follow-up. Participants were also enrolled in a biannual oral hygiene maintenance program. Results The mean age of participants in groups 1 and 2 were 42.4 years (40-46 years) and 41.8 years (39-44 years), respectively. In Group-1, the mean duration of T2 DM was 14.5 ± 0.7 months. At 12 and 24 months of follow-up, there was no significant difference in the mean HbA1c levels among patients in groups 1 and 2. At 12 and 24 months of follow-up, there was no significant difference in peri-implant BOP, PD and MBL in both groups. Conclusions Platform-switched implants can remain clinically and radiographically stable in patients with T2 DM in a manner similar to non-diabetic individuals. However, it is emphasized that bone loss around implants is influenced by several factors (such as oral hygiene status, glycemic control and tobacco smoking) and not merely platform switching. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to evaluate prospectively the 12-year outcome of implant-supported single-tooth restorations. Material and methods Originally 45 self-tapping Astra Tech TiOblast® ST-implants were installed by a two-stage protocol in 40 subjects requiring single-tooth prosthetic replacement for a missing tooth. Clinical and radiologic examinations were performed at completion of the prosthetic treatment 4-7 months after implant installation surgery and after 5 and 12 years in function. Results At 12 years 31 patients and 35 implants were available for evaluation. The overall failure rate after 12 years was 10.3% on the subject level and 9.1% on the implant level. The mean bone loss amounted to 0.67 mm (SD 2.20) on a subject level and 0.47 mm (1.72) on an implant level. Three subjects (10%) and three implants (8.6%) were diagnosed with peri-implantitis. Five subjects had experienced technical complications; three incidences of loosening of the abutment retention screw during the first 5 years and two minor porcelain fracture of the crown (two patients) between 5- and 12-years of follow-up. Conclusion The findings reported in this 12-year prospective case series suggest that the use of the Astra Tech dental implants may be a valid treatment alternative for single-tooth replacement prostheses. [ABSTRACT FROM AUTHOR]

Aim To examine the influence of two different neck designs on facial bone crest dimensions in esthetic single implant sites after a 5-to-9-year follow-up analyzed by cone beam computed tomography ( CBCT). Materials and methods Sixty-one patients with an implant-borne single crown following early implant placement in the esthetic zone were enrolled. The test group consisted of a bone level ( BL) neck design exhibiting a hydrophilic micro-rough surface combined with a platform-switching interface ( PS) ( n = 20). The control group comprised a soft tissue level ( STL) neck design exhibiting a hydrophobic machined surface with a matching butt-joint interface ( n = 41). Standardized clinical, radiologic, and esthetic parameters were applied. The facial bone crest dimensions were assessed by CBCT. Results Soft tissue parameters and pink esthetic scores yielded no significant differences between the two designs. Major differences were only observed at the implant shoulder level. The height of the facial bone crest for the BL design was located 0.2 mm above the implant shoulder level, whereas for the STL design, its location was 1.6 mm below. The width of the peri-implant saucer-like bone defect was reduced by 40% for the BL implant design. No differences were observed 2 mm below the shoulder level. Conclusions The results of this comparative study suggest better crestal bone stability on the facial aspect of single implant sites in the esthetic zone for a BL design with a platform-switching concept when compared with STL implants with a butt-joint interface. [ABSTRACT FROM AUTHOR]

Objectives (1) To assess whether there is evidence of an association between the number of peri-implant tissue complications and patient characteristics such as gender, diabetes status, smoking status, and bite force; (2) To assess whether there is evidence of an association between the number of peri-implant tissue complications and location of the implant, surgical technique used, bone graft status and sinus lift status. Materials and methods This randomized, controlled clinical trial included a total of 176 implants (OsseoSpeed, DENTSPLY) in 67 participants with 88 fixed dental prostheses. Information was obtained from health histories, a baseline exam, surgical notes, and post-operative exams. The data were analyzed using Fisher's exact and Mann-Whitney tests and generalized estimating equations using logistic regression with a significance level set at 0.05. Results All 176 implants survived within a recall period of 3 years, but 11 implants demonstrated peri-implant tissue complications. Ten sites showed dehiscence and one case exhibited vertical bone loss. There was a statistically significant association between surgical technique used (1-stage or 2-stage) and the presence of soft tissue complications ( P = 0.005), where 2-stage surgery was associated with a higher frequency of peri-implant soft tissue complications. A correlation, although not statistically significant ( P = 0.077), was noted, between peri-implant tissue complications and bone grafting, suggesting a possible role for this factor as well. Conclusions Participants who did not require any second-stage surgery at the implant sites experienced fewer complications. Therefore, additional surgical procedures should be performed judiciously considering their possible effects on peri-implant tissue health. Clinical significance The clinical implication of this research study is that secondary surgery should be considered with caution during implant placement and it should be performed only when other options have been exhausted, as it has been shown to have a direct adverse effect on the long-term peri-implant tissue health. [ABSTRACT FROM AUTHOR]

Introduction Although peri-implant bone loss is one of the parameters included in the criteria for determining implant success, its prevention is of vital importance. The goal of this article is to assess the factors that affect peri-implant bone loss. Material and methods An observational, longitudinal, retrospective study was conducted in 148 partially edentulous patients rehabilitated with implants and with a follow-up period of 5 years or more. A total of 585 implants were included in the study. Radiographic peri-implant bone loss was compared with radiographic periodontal bone loss, and other characteristics such as prosthesis design, hygiene, and implant size were studied as potential peri-implant bone loss modification factors. Results In the univariate analysis, a statistically significant relationship between peri-implant bone loss and gender ( P < 0.05), implant system ( P < 0.01), reason for extraction ( P < 0.05), splinting ( P < 0.0001), and distance between the implant platform and the horizontal component of the prosthesis ( P < 0.0001) were observed. In multivariate analysis, the relationship between this peri-implant loss and gender ( P < 0.05), implant system ( P < 0.05), splinting ( P < 0.001), and the aforementioned distance ( P < 0.01) remains. Conclusions The distance implant platform-horizontal component of the prosthesis has the greatest effect on peri-implant bone loss This distance must be >3.3 mm and <6 mm, above this range, it no longer influences in peri-implant bone loss and favors the appearance of embrasures and the buildup of bacterial plaque. [ABSTRACT FROM AUTHOR]

Objectives The aim of the present longitudinal study was to investigate bacterial colonization of the internal implant cavity and to evaluate a possible association with peri-implant bone loss. Methods A total of 264 paper point samples were harvested from the intra-implant cavity of 66 implants in 26 patients immediately following implant insertion and after 3, 4, and 12 months. Samples were evaluated for Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, and Tannerella forsythia as well as total bacterial counts by real-time PCR. Bone loss was evaluated on standardized radiographs up to 25 months after implant insertion. For the statistical analysis of the data, mixed effects models were fitted. Results There was an increase in the frequency of detection as well as in the mean counts of the selected bacteria over time. The evaluation of the target bacteria revealed a significant association of Pr. intermedia at 4 and 12 months with peri-implant bone loss at 25 months (4 months: P = 0.009; 12 months: P = 0.021). Conclusions The present study could demonstrate a progressive colonization by periodontopathogenic bacteria in the internal cavities of two-piece implants. The results suggest that internal colonization with Pr. intermedia was associated with peri-implant bone loss. [ABSTRACT FROM AUTHOR]

Aim To evaluate the outcomes of conventional periodontal maintenance therapy on patients surgically treated for peri-implantitis. Material and methods 27 patients with 149 dental implants were monitored during 5 years every 6 months. At each recall visit, the prostheses were removed to have proper access for implant examination and supra- and sub-gingival instrumentation. Sub-gingival instrumentation was performed using an ultrasonic instrument with under 0.12% chlorhexidine irrigation. Results At baseline (6 months following peri-implant surgery), 149 implants (78 not treated and 71 treated) were available for analysis. Of the 71 treated implants, 43 presented healthy peri-implant condition, while 28 had residual peri-implant pockets either of 4-5 mm or ≥6 mm associated with bleeding on probing/suppuration. The longitudinal evaluation revealed that the plaque and the bleeding index scores were low during the entire follow-up period, and healthy peri-implant conditions were maintained for both the 78 non-treated and the 43 treated 'healthy' implants. Of the 28 implants with residual pockets, nine showed clinical attachment loss during the 5-year follow-up. Thus, of 71 treated implants, probing attachment loss occurred in only in 9 (13%) of the implants in four patients during the 5-year period. The presence of residual pockets at three or four sites of the implants (circumferential type of pockets) was frequently associated with increased probing pocket depth ( PPD) and attachment loss, while this was not the case for implants with the presence of pockets at one or two sites only (site specific). Conclusion In patients with a high standard of oral hygiene and enrolled in a recall system every 6 months, the peri-implant conditions obtained following peri-implant surgery were maintained stable for the majority of subjects and implants during a 5-year period. Presence of residual pockets around the circumference of the implants seemed to be a high predictor for disease progression. [ABSTRACT FROM AUTHOR]

Objective This study aimed to classify peri-implant bone defects ( PIBDs) on the basis of their radiographic appearance in a cohort of patients with lower implant-supported overdentures. Materials and methods Eighty-three patients with lower implant-supported overdentures were recruited to participate in the study, which was approved by the ethics committee of Ignatius Teaching Hospital. Details about the patients' smoking habits were recorded. The participants had a total of 224 implants involving 3214 implant sites. The mean observation time of the subjects was 10.7 years. Panoramic radiographs of all sites were evaluated in duplicate (first evaluation [t1], second evaluation [t2]) during 2 weeks by one experienced observer. PIBDs were classified into the following types: saucer-shaped, wedge-shaped, flat, undercut, and slit-like bone defects. Intra-examiner agreement was tested using crosstabs and Cohen's kappa coefficient. The association of PIBD type with gender, time after implant placement, smoking, and treatment strategy was investigated using multivariate test of independence on the basis of spatial signs. Results Intra-observer reliability was moderate (κ = 0.51). Saucer-shaped defects were the most frequent (42.8% [t1] and 44.6% [t2]), followed by wedge-shaped (26.0% [t1] and 27.4% [t2]), flat (10.7% [t2] and 17.7% [t1]), undercut (8.8% [t1] and 11.9% [t2]), and finally slit-like defects (4.7% [t1] and 5.4% [t2]). Peri-implant bone defects morphology was significantly associated with gender, smoking, and treatment strategy. Conclusion The morphology of PIBDs can be classified into five meaningful classes, as opposed to the two described in the literature. [ABSTRACT FROM AUTHOR]

Aim To assess the clinical and radiographic outcomes applying a combined resective and regenerative approach in the treatment of peri-implantitis. Materials and methods Subjects with implants diagnosed with peri-implantitis (i.e., pocket probing depth ( PPD) ≥5 mm with concomitant bleeding on probing (BoP) and ≥2 mm of marginal bone loss or exposure of ≥1 implant thread) were treated by means of a combined approach including the application of a deproteinized bovine bone mineral and a collagen membrane in the intrabony and implantoplasty in the suprabony component of the peri-implant lesion, respectively. The soft tissues were apically repositioned allowing for a non-submerged healing. Clinical and radiographic parameters were evaluated at baseline and 12 months after treatment. Results Eleven subjects with 11 implants were treated and completed the 12-month follow-up. No implant was lost yielding a 100% survival rate. At baseline, the mean PPD and mean clinical attachment level ( CAL) were 8.1 ± 1.8 mm and 9.7 ± 2.5 mm, respectively. After 1 year, a mean PPD of 4.0 ± 1.3 mm and a mean CAL of 6.7 ± 2.5 mm were assessed. The differences between the baseline and the follow-up examinations were statistically significant ( P = 0.001). The mucosal recession increased from 1.7 ± 1.5 at baseline to 3.0 ± 1.8 mm at the 12-month follow-up ( P = 0.003). The mean% of sites with BoP+ around the selected implants decreased from 19.7 ± 40.1 at baseline to 6.1 ± 24.0 after 12 months ( P = 0.032). The radiographic marginal bone level decreased from 8.0 ± 3.7 mm at baseline to 5.2 ± 2.2 mm at the 12-month follow-up ( P = 0.000001). The radiographic fill of the intrabony component of the defect amounted to 93.3 ± 13.0%. Conclusion Within the limits of this study, a combined regenerative and resective approach for the treatment of peri-implant defects yielded positive outcomes in terms of PPD reduction and radiographic defect fill after 12 months. [ABSTRACT FROM AUTHOR]

Objectives Bone formation and maintenance around implants placed immediately after tooth extraction may be affected by implant surface treatment and compromise long-term esthetic results. This study morphometrically evaluated buccal bone loss and bone-to-implant contact ( BIC) of four implant systems placed immediately after tooth extraction in a dog model. Material and Methods The premolars of eight beagle dogs were bilaterally extracted with a full-thickness flap, and root-form dental implants were placed on the root extraction socket. Implants ( n = 16 each) with different surface treatments were placed from sites 1 to 4 and alternated between animals to allow evaluation of the same number of implants at sites and evaluation time points. Implant surface treatments were as follows: anodized, discrete crystalline deposition, SLActive, and microblasted. The left and right side provided implants that stayed for 2 and 4 weeks, respectively. Submerged healing was allowed and bone-to-implant contact ( BIC) and buccal bone loss were morphometrically measured. Linear mixed models ( P < 0.05) were used to assess differences between groups, across time, and their interaction. Results Buccal bone loss was observed to approximately double between 2 and 4 weeks ( P = 0.01). BIC also increased between 2 and 4 weeks, by 20-25% ( P = 0.01). These changes were statistically similar for each surface. Conclusion When placed immediately after tooth extraction, the evaluated histomorphometric parameters vary only with time. [ABSTRACT FROM AUTHOR]

Objectives The objective of this study was to compare the placement of flapped vs. flapless dental implants utilizing clinical, radiographic, microbiological, and immunological parameters. Material and methods A total of 20 patients received 30 dental implants following a one-stage protocol. The patients were randomly assigned into two study groups: control group with 15 flapped implants and test group with 15 flapless implants. Follow-up examinations were carried out after 1, 2, 6, and 12 weeks. Clinical recordings, sulcular fluid sampling, microbiological analysis, and digital subtraction radiography were utilized to compare the two surgical approaches. Results Peri-implant sulcus depth was significantly greater in flapped implants at both 6 and 12 postsurgical weeks ( P < 0.001). Flapped implants showed crestal bone loss (0.29 ± 0.06 mm), whereas no bone resorption was detected around flapless implants. Matrix metalloproteinase-8 values were higher to a statistically significant level in the control group at 1 ( P = 0.003) and 6 weeks ( P = 0.007) after placement. In the test group, the presence of Porphyromonas gingivalis was significantly higher at the 2nd postoperative week ( P = 0.005), whereas the counts of Tannerella forsythia were significantly elevated at the 1st ( P = 0.005), 2nd ( P = 0.001), and 12th ( P = 0.002) postoperative weeks, possibly indicating an earlier formation and maturation of the peri-implant sulcus. Patients reported more pain after flapped implant placement. Conclusions Flapless implant placement yielded improved clinical, radiographic, and immunological outcomes compared with flapped implantation. In addition, patients seem to better withstand flapless implant placement. [ABSTRACT FROM AUTHOR]

Objectives To evaluate the probing depth at implants with signs of peri-implantitis before and following the removal of the prosthetic reconstructions and its relation with the peri-implant bone level as revealed by open access flap surgery. Material and methods Twenty-nine patients with 89 implants with diagnosis of peri-implantitis were included in the study. The probing pocket depth at implants before ( PPD-1) and following ( PPD-2) the removal of the prosthetic reconstructions was measured at four sites of the implants. These measurements were also analysed in relation to the amount of peri-implant bone loss measured during peri-implant surgery. Results The results showed that in only 119 (37%) of the sites, the measurements were similar between PPD-1 and PPD-2; in 124 sites (39%), the difference was ±1 mm, in 47 sites (15%) it was ±2 mm and in the rest of the sites it was ±3 mm. A high linear and statistically significant ( P = <0.001) correlation between PPD-2 and the bone loss measured at implants for all and single surfaces was observed (r = 0.67, range 0.64-0.69), while PPD-1 yielded a weak and no statistically significant correlation (r = 0.35, range 0.27-0.42). The analysis of the bone loss at implants showed that 59 implants (66%) had an amount of bone loss that was similar at all the four surfaces, while in 30 implants, the bone loss differed for the various sites. A higher extent of bone loss was often detected at the buccal compared with the other sites. Conclusion The results of this study yielded differences in the pocket probing measurements at implants with or without the prosthetic reconstruction in place and that the probing pocket depth following the removal of the prosthesis had a high correlation with the amount of bone loss at implants assessed during surgery. [ABSTRACT FROM AUTHOR]

Aim The aim of this search was to assess the biological consequences that overload might have on already osseointegrated oral implants through a systematic screening of the scientific literature. Method Detailed searches through PUBMED, OVID, EMBASE and LILACS databases were made. Articles published up to December 2011 and those reported on the clinical, radiographic and/or histological outcome of oral implants subjected to so-called overload were considered eligible for inclusion. Identified studies were assessed by one non-blinded reviewer according to well-defined inclusion and exclusion criteria. When doubt arose, the co-authors were counselled until final agreement was obtained. The PICO questions formulated was:'what is the effect of overload vs. no overload on bone/implant loss in clinically stable implants?' Results The database searches as well as additional hand searching, resulted in 726 potentially relevant titles. Eventually, 16 clinical and 25 animal studies were considered relevant to the topic. After inclusion/exclusion criteria assessment, all clinical studies and all but three animal studies and one systematic review were considered at high risk of bias and excluded. The included animal studies did not reveal an association between overload and peri-implant bone loss in the absence of peri-implant inflammation, whereas in its presence, overload seemed to aggravate the peri-implant tissue breakdown. Conclusions The effect of implant overload on bone/implant loss in clinically well-integrated implants is poorly reported and provides little unbiased evidence to support a cause-and-effect relationship. The PICO question remained unanswered. At the animal level, 'overload', mimicked by supra-occlusal contacts acting in an uninflamed peri-implant environment, did not negatively affect osseointegration and even was anabolic. In contrast, supra-occlusal contacts in the presence of inflammation significantly increased the plaque-induced bone resorption. [ABSTRACT FROM AUTHOR]

Objectives The aim of this study was to evaluate short-term bone level and stability/mobility measurement alterations at platform switched ( PS) and standard platform ( SP) implants placed in mandibular premolar/molar regions using a single-stage protocol. Materials and methods Sixteen PS and 16 SP implants restorated with fixed prosthesis were included. Standard implant dimensions were used for both implant systems. After 3 months of osseointegration, implants were connected to abutments and final restorations were performed. Marginal bone loss was measured by standardized periapical radiographs. Implant stability/mobility was determined by resonance frequency analysis ( RFA) and mobility measuring ( MM) device values. Peri-implant parameters were evaluated with clinical periodontal indices and all parameters were assessed at baseline, 1, 3, and 6 months after the surgery. Results After 6 months, all implants showed uneventful healing. Radiographic evaluation showed a mean bone loss of 0.72 mm for PS and 0.56 mm for SP implants, and there were no significant differences between implant types. At 6 months, mean implant stability quotient ( ISQ) values were 73.38 and 77 for PS and SP implants, respectively. Mean MM values were −4.75 for PS and −6.38 for SP implants. Mean MM values were lower for SP implants compared to PS implants at all time points. No significant differences were detected between implant types according to clinical peri-implant parameters. Conclusions The micro-gap at crestal level which immediately exposed to the oral cavity in non-submerged two part implants seems to have adverse influence on the marginal bone level. [ABSTRACT FROM AUTHOR]

Objectives: To test an extended subtraction method for measuring changes in bone along dental implants depicted on non-standardized panoramic radiographs. Material and methods: The measuring method consisted of a subtraction module extended with modules correcting gray values, correcting geometry and defining the region of interest mesial and distal of dental implants. It was applied to an archive of panoramic radiographs of implant patients who had been monitored up to 16 years. Results: Significant loss of gray value was demonstrated at a constant rate of 0.6 units per month throughout the study. This indicates gradual bone loss on the mesial and/or distal sides of the implants. Females were found to lose bone at a higher rate than males. Smokers and non-smokers, and various implant strategies yielded the same rate of bone loss. Conclusions: The measuring method is a helpful tool to monitor changes around implants even when non-standardized radiographs are being used. Whereas changes of marginal bone level are increased five to eight times during the first year after surgery, the present method shows gradual loss of bone during 15 years after surgery. To cite this article: Geraets WGM, Verheij HGC, Wismeijer D, van der Stelt PF. Detecting bone loss along dental implants by subtraction of panoramic radiographs. Clin. Oral Impl. Res. 23, 2012; 861-865. doi: 10.1111/j.1600-0501.2011.02215.x [ABSTRACT FROM AUTHOR]

Aim: To compare the survival and peri-implant bone loss of implants with a fluoride-modified surface in smokers and nonsmokers. Materials and methods: Patient files of all patients referred for implant treatment from November 2004 to 2007 were scrutinized. All implants were placed by the same experienced surgeon (B. C.). The only inclusion criterion was a follow-up time of at least 2 years. Implant survival and bone loss were assessed by an external calibrated examiner (S. V.) comparing digital peri-apical radiographs taken during recall visits with the post-operative ones. Implant success was determined according to the international success criteria (Albrektsson et al. 1986). Survival of implants installed in smokers and nonsmokers was compared using the log-rank test. Both nonparametric tests and fixed model analysis were adopted to evaluate bone loss in smokers and nonsmokers. Results: One-thousand one-hundred and six implants in 300 patients (186 females; 114 males) with a mean follow-up of 31 months (SD 7.15; range 24-58) were included. Nineteen implants in 17 patients failed, resulting in an overall survival rate of 98.3% at the implant level and 94.6% at the patient level. After a follow-up period of 2 years, the cumulative survival rates was 96.7% and 99.1% with the patient and implant as the statistical unit, respectively. Implant survival was significantly higher for nonsmokers compared with smokers (implant level P=0.025; patient level P=0.017). The overall mean bone loss was 0.34 mm ( n=1076; SD 0.65; range 0-7.1). Smokers lost significantly more bone compared with nonsmokers in the maxilla (0.74 mm; SD 1.07 vs. 0.33 mm; SD 0.65; P<0.001), but not in the mandible (0.25 mm; SD 0.65 vs. 0.22 mm; SD 0.5; P=0.298). Conclusion: The present study is the first to compare peri-implant bone loss in smokers and nonsmokers from the time of implant insertion (baseline) to at least 2 years of follow-up. Implants with a fluoride-modified surface demonstrated a high survival rate and limited bone loss. However, smokers are at a higher risk of experiencing implant failure and more prone to show peri-implant bone loss in the maxilla. Whether this bone loss is predicting future biological complications remains to be evaluated. [ABSTRACT FROM AUTHOR]

Objectives To evaluate the clinical and radiographic changes at implants in posterior maxillary and mandibular areas supporting single-unit crowns ( SCs) and fixed dental prostheses ( FDPs) with one mesial or distal cantilever extension after an observation period of at least 3 years. Material and methods Seventeen subjects with 19 implant-supported SCs and 21 subjects with 21 implant-supported FDPs fulfilled the inclusion criteria. All FDPs were supported by two implants and had a span of 3-4 units. All reconstructions were incorporated in the posterior maxilla or mandible. The mesial and distal radiographic marginal bone loss from baseline (i.e. delivery of the reconstruction) to the follow-up examination was averaged and compared between SCs supporting one cantilever extension with that of implants supporting FDPs adjacent to or distant from the cantilever extension. Changes in mean pocket probing depth ( PPD) were calculated and compared between the three groups. Results The mean observation period was 78.2 ± 34.5 months for SCs supported by one implant and 67.8 ± 29.8 months for FDPs supported by two implants. No implant loss occurred, yielding a 100% survival rate. At baseline, the mean radiographic bone levels ± SD were 2.6 ± 0.3 mm for implants supporting SCs, 2.6 ± 0.3 mm for implants of FDPs adjacent to the cantilever extension, and 2.4 ± 0.5 mm for implants of FDPs distant from the cantilever extension. At follow-up, the corresponding mean bone levels ± SD were 2.7 ± 0.4, 2.7 ± 0.5, and 2.8 ± 0.5 mm, respectively. No statistically significant differences ( P > 0.05) were observed comparing the mean marginal bone loss between the three groups. Moreover, mean changes in PPD between baseline and follow-up were not statistically significantly different ( P > 0.05) between the three groups. Conclusion The presence of one mesial or distal cantilever extension in the posterior maxilla or mandible does not jeopardize the marginal bone levels of implants supporting SCs or short-span FDPs after a mean observation period of at least 5 years. [ABSTRACT FROM AUTHOR]

Aim This 1-year prospective RCT compared the outcome of minimally (turned) and moderately rough (TiUnite®) implant surfaces. Material and methods Two subgroups of patients were formed; one group ( n = 10) where all teeth had been extracted due to severe periodontitis, another group ( n = 8) with teeth in the antagonistic jaw with a history of periodontitis and some remaining medium pockets (4-6 mm). Implants ( n = 85, 43 turned & 42 TiUnite®) were installed randomly in each patient. After 3-6 months of submerged healing, healing abutments were connected, followed by final abutments 2 weeks later, all with the same surface characteristics as the supporting implant. Peri-implant parameters and intra-oral radiographs were recorded up to 1 year after abutment connection. Results Two turned implants failed in the partial edentulous group during the initial healing period ( CSR: 95%) and none of the TiUnite® ( CSR: 100%) surface. No statistically significant differences in clinical parameters could be observed between both surfaces. The partial edentulous subgroup showed more bone loss compared to the full edentulous subgroup. Conclusion Moderately rough implants have a similar clinical outcome (at 1 year of loading in periodontitis susceptible patients) compared to minimally rough implants. [ABSTRACT FROM AUTHOR]

Objectives: The concept of platform switching has been introduced to implant therapy, however long-term data are sparse. The aim of this study was to biochemically investigate the inflammatory response mediated by MMP-8 to platform switching after 3 years of loading, in order to understand the long-term effect of implant/abutment mismatching on peri-implant health. Methods: A total of 70 implants had been inserted in the posterior maxilla in 26 patients and were randomly assigned to one of the four treatment regimens (implant diameter 3.8 [control group], 4.3 [Test group 1, T1], 4.8 [Test group 2, T2] and 5.5 mm [Test group 3, T3]). All implants were restored using a 3.8 mm abutment. In the test groups, this restoration resulted in a mismatching of 0.25-0.85 mm of implant-abutment diameters. Results: Thirty-six months after prosthetic rehabilitation, peri-implant sulcular fluid samples were taken from two aspects of all implants and from periodontally healthy adjacent teeth. Samples were processed in a conventional ELISA using monoclonal antibodies recognizing the active entity of MMP-8. In the test groups, MMP-8 mean values were 2.76 ng for T1 (SD: 2.91), 3.30 ng for T2 (SD: 1.94) and 3.18 ng for T3 (SD: 2.46). For the control group, MMP-8 mean value was 3.6 ng (SD: 2.23), whereas 3.38 ng (SD: 2.2) was recorded at the adjacent teeth. There were no statistically significant differences in MMP-8 values between the groups ( P=0.113, Kruskal-Wallis). Conclusions: The presence of an implant/abutment mismatching specific for this prosthetic concept is compatible with long-term peri-implant health as demonstrated by analysis of a sensitive biomarker of the peri-implant inflammatory response. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to evaluate and compare marginal bone loss and clinical outcomes of conventionally and immediately loaded two implants supporting a ball-retained mandibular overdenture. Materials and methods: Thirty six completely edentulous patients (22 males and 14 females) were randomly assigned into two groups. Each patient received two implants in the canine area of the mandible after a minimal flap reflection. Implants were loaded by mandibular overdentures either 3 months (conventional loading group) or the same day (immediate loading group) after implant placement. Ball attachments were used to retain all overdentures to the implants. Vertical and horizontal alveolar bone losses were evaluated in both groups 1 and 3 years after implant placement using multislice computed tomography, which allow evaluation of peri-implant buccal and lingual alveolar bone. Plaque scores, gingival scores, probing depths and periotest values (PTVs) were evaluated at 4 months (baseline), 1 and 3 years after implant placement. Clinical and radiographic evaluations were performed at distal, labial, mesial and lingual peri-implant sites. Results: After 3 years of follow-up period, the immediate loading group recorded significant vertical bone loss at distal and labial sites than the conventional loading group and no significant differences in horizontal bone loss between groups were observed. Probing depth at distal and labial sites in the immediate loading group were higher than the conventional loading group, while plaque scores, gingival scores and PTVs showed no significant differences between the two groups. A low level of positive correlation between plaque scores, gingival scores, probing depths and vertical bone loss was noted. Conclusion: Immediately loaded two implants supporting a ball-retained mandibular overdenture are associated with more marginal bone resorption and increased probing depths when compared with conventionally loaded implants after 3 years. The bone resorption and probing depths at distal and labial sites are significantly higher than those at mesial and lingual sites. Clinical outcomes do not differ significantly between loading protocols. To cite this article: Elsyad MA, Al-Mahdy YF, Fouad MM. Marginal bone loss adjacent to conventional and immediate loaded two implants supporting a ball-retained mandibular overdenture: a 3-year randomized clinical trial. Clin. Oral Impl. Res. 23, 23, 2012 496-503. doi: 10.1111/j.1600-0501.2011.02173.x [ABSTRACT FROM AUTHOR]

Objectives The aim of this retrospective study was to compare the clinical outcomes of implant treatment in periodontally compromised and periodontally healthy patients ( PHP), with a minimum follow-up period of 5 years. Methods Thirty treated periodontally compromised patients ( PCP) and 30 PHP, with a total of 117 Straumann implants ( PCP = 56, PHP = 61) were matched for age, gender, smoking and implant characteristics. The PCP group was further stratified with patients having at least one periodontal pocket ≥6 mm at follow-up examination allocated to a 'residual periodontitis' ( RP) group, while the remaining patients were assigned to a 'no residual periodontitis' ( NRP) group. These groups were compared with respect to probing pocket depth ( PPD), bleeding on probing ( BOP) and marginal bone loss. Results The mean follow-up period in the PCP and PHP groups was 7.99 years (range 5.04-14.40) and 8.20 years (range 5.00-13.46) respectively. There was no difference in mean PPD between the PCP and PHP groups, but the prevalence of implants with PPD ≥5 mm + BOP was greater in the PCP group than in the PHP group, at both implant- (27% vs. 13%) and patient- (37% vs. 17%) level analyses. Mean implant PPD was significantly greater in the RP group (3.18 mm) than in both the NRP (2.67 mm) and PHP (2.81 mm) groups. Mean bone loss was also significantly greater in the RP group (0.68 mm) than in the NRP (0.23 mm) and PHP groups (0.26 mm). The prevalence of bone loss and PPD ≥5 mm + BOP at the implant level was significantly greater for the RP group compared with both the NRP and PHP groups. Conclusions Implants in PCP with residual pocketing at follow-up had increased PPD and bone loss compared with implants placed in PHP and PCP without residual pocketing. Hence, it is the maintenance of periodontal health rather than a previous history of periodontitis that is the critical determinant of increased risk of peri-implantitis, highlighting the importance of effective periodontal therapy and maintenance in patients with a history of periodontitis. [ABSTRACT FROM AUTHOR]

Objective: The concept of platform switching has been introduced to implant dentistry based on observations of reduced peri-implant bone loss. However, randomized clinical trials are still lacking. This study aimed to test the hypothesis that platform switching has a positive impact on crestal bone-level changes. Material and methods: Two implants with diameters of 4 mm were inserted epicrestally into one side of the posterior mandibles of 25 subjects. After 3 months of submerged healing, the reentry surgery was performed. On the randomly placed test implant, an abutment 3.3 mm in diameter was mounted, resulting in a horizontal circular step of 0.35 mm (platform switching). The control implant was straight, with an abutment 4 mm in diameter. Single-tooth crowns were cemented provisionally. All patients were monitored at short intervals over the course of 1 year. Standardized radiographs and microbiological samples from the implants' inner spaces were obtained at baseline (implant surgery), and after 3, 4, and 12 months. Results: After 1 year, the mean radiographic vertical bone loss at the test implants was 0.53±0.35 mm and at the control implants, it was 0.58±0.55 mm. The mean intraindividual difference was 0.05±0.56 mm, which is significantly <0.35 mm ( P=0.0093, post hoc power 79.9%). The crestal bone-level changes depended on time ( P<0.001), but not on platform switching ( P=0.4). The implants' internal spaces were contaminated by bacteria, with no significant differences in the total counts between the test and the control at any time point ( P=0.98). Conclusions: The present randomized clinical trial could not confirm the hypothesis of a reduced peri-implant bone loss at implants restored according to the concept of platform switching. To cite this article: Enkling N, Jöhren P, Klimberg V, Bayer S, Mericske-Stern R, Jepsen S. Effect of platform switching on peri-implant bone levels: a randomized clinical trial. Clin. Oral Impl. Res. 22, 2011; 1185-1192. doi: 10.1111/j.1600-0501.2010.02090.x [ABSTRACT FROM AUTHOR]

Objective: To assess, based on the existing literature, the benefit of socket preservation therapies in patients with a tooth extraction in the anterior or premolar region as compared with no additional treatment with respect to bone level. Material and methods: MEDLINE‐PubMed and the Cochrane Central Register of controlled trials (CENTRAL) were searched till June 2010 for appropriate studies, which reported data concerning the dimensional changes in alveolar height and width after tooth extraction with or without additional treatment like bonefillers, collagen, growth factors or membranes. Results: Independent screening of the titles and abstracts of 1918 MEDLINE‐PubMed and 163 Cochrane papers resulted in nine publications that met the eligibility criteria. In natural healing after extraction, a reduction in width ranging between 2.6 and 4.6 mm and in height between 0.4 and 3.9 mm was observed. With respect to socket preservation, the freeze‐dried bone allograft group performed best with a gain in height, however, concurrent with a loss in width of 1.2 mm. Conclusion: Data concerning socket preservation therapies in humans are scarce, which does not allow any firm conclusions. Socket preservation may aid in reducing the bone dimensional changes following tooth extraction. However, they do not prevent bone resorption because, depending on the technique, on the basis of the included papers one may still expect a loss in width and in height. To cite this article: 
Ten Heggeler JMAG, Slot DE, Van der Weijden GA. Effect of socket preservation therapies following tooth extraction in non‐molar regions in humans: a systematic review.
Clin. Oral Impl. Res. 22, 2011; 779–788
doi: 10.1111/j.1600‐0501.2010.02064.x. [ABSTRACT FROM AUTHOR]

To compare the 10-year marginal bone loss rates around implants supporting single-unit crowns in tobacco smokers with and without a history of treated periodontitis. In this retrospective controlled study, 40 tobacco smokers were divided into four groups of 10 patients each. Two groups of periodontally compromised (PC) patients and two groups of periodontally healthy (PH) patients were established. PC patients had been treated for their periodontal conditions before implant placement. All patients were enrolled in a regular, individually tailored maintenance care program. For the rehabilitation of PC and PH patients, two different types of implants were used (Nobel Biocare AB; Straumann Dental Implant System). The radiographic bone loss rate was calculated by subtracting the bone levels at the time of crown delivery from the bone levels at the 10-year follow-up. The mean age, mean full-mouth plaque score and full-mouth bleeding score and implant location were similar for the four groups. Implant survival rates ranged between 70% and 100%, without statistically significant differences between the four groups ( P>0.05). Implants placed in PC patients yielded statistically significantly higher marginal bone loss rates compared with those in PH patients ( P<0.05), independent of the implant system used. After 10 years, implants placed in tobacco smokers with a history of treated periodontitis and enrolled in a supportive therapy program yielded lower survival rates and higher marginal bone loss rates compared with those of implants placed in PH smokers. These outcomes were independent of the implant system installed or the healing modality applied. Aglietta M, Iorio Siciliano V, Rasperini G, Cafiero C, Lang NP, Salvi GE. A 10-year retrospective analysis of marginal bone-level changes around implants in periodontally healthy and periodontally compromised tobacco smokers Clin. Oral Impl. Res. , 2011; 47-53. doi: 10.1111/j.1600-0501.2010.01977.x [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to analyze the evolution of implant mechanical stability in different types/sizes of bony defects using both Periotest and Osstell devices as “objective tools.” Materials and methods: Thirty-two implants were randomly allocated to one of the four types of bone defects: marginal bone loss, peri-apical bone defect, constant width dehiscence and constant length dehiscences. Periotest/Osstell measurements were completed before and during staged bone removal (to enlarge defect size). Results: Significant differences ( P<0.05) with initial values were found after a 2 mm marginal bone removal (Osstell/Periotest); for a peri-apical bone lesion, after removal of 5 mm (Osstell) or 8 mm (Periotest); for a 6-mm-long dehiscence, after removal up to 180° of the implant perimeter (Osstell/Periotest); for a 3-mm-wide dehiscence, after removal of 10 mm (Osstell) or 6 mm (Periotest). Conclusion: Periotest and Osstell are in general not very sensitive in the identification of peri-implant bone destruction, except for marginal bone loss. To cite this article: Merheb J, Coucke W, Jacobs R, Naert I, Quirynen M. Influence of bony defects on implant stability. Clin. Oral Impl. Res. 21, 2010; 919–923. doi: 10.1111/j.1600-0501.2010.01932.x [ABSTRACT FROM AUTHOR]

Aim: To compare the 10-year peri-implant bone loss (BL) rate in periodontally compromised (PCP) and periodontally healthy patients (PHP) around two different implant systems supporting single-unit crowns. Materials and methods: In this retrospective, controlled study, the mean BL (mBL) rate around dental implants placed in four groups of 20 non-smokers was evaluated after a follow-up of 10 years. Two groups of patients treated for periodontitis (PCP) and two groups of PHP were created. For each category (PCP and PHP), two different types of implant had been selected. The mBL was calculated by subtracting the radiographic bone levels at the time of crown cementation from the bone levels at the 10-year follow-up. Results: The mean age, mean full-mouth plaque and full-mouth bleeding scores and implant location were similar between the four groups. Implant survival rates ranged between 85% and 95%, without statistically significant differences ( P>0.05) between groups. For both implant systems, PCP showed statistically significantly higher mBL rates and number of sites with BL≥3 mm compared with PHP ( P<0.0001). Conclusions: After 10 years, implants in PCP yielded lower survival rates and higher mean marginal BL rates compared with those of implants placed in PHP. These results were independent of the implant system used or the healing modality applied. To cite this article: Matarasso S, Rasperini G, Iorio Siciliano V, Salvi GE, Lang NP, Aglietta M. A 10-year retrospective analysis of radiographic bone-level changes of implants supporting single-unit crowns in periodontally compromised vs. periodontally healthy patients. Clin. Oral Impl. Res. 21, 2010; 898–903. doi: 10.1111/j.1600-0501.2010.01945.x [ABSTRACT FROM AUTHOR]

Objective: In part 2 of this long-term, retrospective study on the two-implant-supported overdenture in the mandible, the annual marginal bone loss was evaluated in detail and parameters, with a significant effect on the annual bone loss, were verified. Material and methods: For all 495 patients with an overdenture in the mandible at least 5 years in function, data up to their last follow-up visit had been collected, including long-cone radiographs (taken at the abutment connection and after years 1, 3, 5, 8, 12 and 16 of loading) and probing data at their last evaluation. General information (medical history, implant data, report on surgery) was retrieved from the patient's file. Two hundred and forty-eight patients had been clinically examined recently. For the others, information on bone level and probing depths were retrieved from the patient's files, as all patients had been enrolled in our annual follow-up schedule. Results: The mean annual bone loss on a site level (without considering the first year of bone remodelling) after 3 years of loading was 0.08 mm/year (SD=0.22, n=1105), after 5 years of loading 0.07 mm/year (SD=0.14, n=892), after 8 years of loading 0.06 mm/year (SD=0.12, n=598), after 12 years 0.04 mm/year (SD=0.07, n=370) and 0.05 mm/year (SD=0.05, n=154) after 16 years of loading. Ongoing bone loss was seen in a number of implants ( n=26) with the annual bone loss exceeding 0.2 mm. Some factors clearly showed a significant impact on bone loss: smoking (≥10 cigarettes/day), GBR, the presence of dehiscence and bone quantity(the latter only during the first year). The probing data showed a favourable condition, with <1.2% of the approximal pockets being ≥6 mm, and 4.1%=5 mm. Conclusions: The mean annual bone loss over the study period was <0.1 mm/year after the first year of loading. However, a small number (2.5%) of the implants showed continuing bone loss. To cite this article: Vercruyssen M, Quirynen M. Long-term, retrospective evaluation (implant and patient-centred outcome) of the two-implants-supported overdenture in the mandible. Part 2: marginal bone loss. Clin. Oral Impl. Res. 21, 2010; 466–472. doi: 10.1111/j.1600-0501.2009.01902.x [ABSTRACT FROM AUTHOR]

Objectives: This randomized-controlled trial aimed to evaluate marginal bone level alterations at implants restored according to the platform-switching concept, using different implant/abutment mismatching. Material and methods: Eighty implants were divided according to the platform diameter in four groups: 3.8 mm (control), 4.3 mm (test group1), 4.8 mm (test group2) and 5.5 mm (test group3), and randomly placed in the posterior maxilla of 31 patients. After 3 months, implants were connected to a 3.8-mm-diameter abutment and final restorations were performed. Radiographic bone height was measured by two independent examiners at the time of implant placement (baseline), and after 9, 15, 21 and 33 months. Results: After 21 months, all 80 implants were clinically osseointegrated in the 31 patients treated. A total of 69 implants were available for analysis, as 11 implants had to be excluded from the study due to early unintentional cover screw exposure. Radiographic evaluation showed a mean bone loss of 0.99 mm (SD=0.42 mm) for test group1, 0.82 mm (SD=0.36 mm) for test group2 and 0.56 mm (SD=0.31 mm) for test group3. These values were statistically significantly lower ( P<0.005) compared with control (1.49 mm, SD=0.54 mm). After 33 months, five patients were lost to follow-up. Evaluation of the remaining 60 implants showed no difference compared with 21 months data except for test group2 (0.87 mm) and test group3 (0.64 mm). There was an inverse correlation between the extent of mismatching and the amount of bone loss. Conclusions: This study suggested that marginal bone level alterations could be related to the extent of implant/abutment mismatching. Marginal bone levels were better maintained at implants restored according to the platform-switching concept. To cite this article: Canullo L, Fedele GR, Iannello G, Jepsen S. Platform switching and marginal bone-level alterations: the results of a randomized-controlled trial. Clin. Oral Impl. Res. 21, 2010; 115–121. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this review was to evaluate the effect of different implant surfaces and designs on marginal bone-level (MBL) alterations. Material and methods: A MEDLINE search (PubMed) was performed to identify clinical, prospective and controlled studies using a sufficient sample size (>10 subjects) and with a follow-up time of ≥3 years. Results: Ten publications fulfilled the inclusion criteria. Two studies evaluated the influence of implant surface characteristics and two studies reported on the effect of implant design on MBL changes. Six publications analyzed the combined effect of different implant surfaces and designs on MBL alterations. As revealed from available studies, there is no evidence that modified surfaces are superior to non-modified implant surfaces in marginal bone preservation. One study reported on significantly improved MBL preservation for implants with a conical and micro-threaded marginal collar than implants with a cylindrical and non-threaded marginal portion after 3 years in function. No implant system was found to be superior in marginal bone preservation. [ABSTRACT FROM AUTHOR]

Objective: The aim of this systematic review was to assess the survival rates of short-span implant-supported cantilever fixed dental prostheses (ICFDPs) and the incidence of technical and biological complications after an observation period of at least 5 years. Material and methods: An electronic MEDLINE search supplemented by manual searching was conducted to identify prospective or retrospective cohort studies reporting data of at least 5 years on ICFDPs. Five- and 10-year estimates for failure and complication rates were calculated using standard or random-effect Poisson regression analysis. Results: The five studies eligible for the meta-analysis yielded an estimated 5- and 10-year ICFDP cumulative survival rate of 94.3% [95 percent confidence interval (95% CI): 84.1–98%] and 88.9% (95% CI: 70.8–96.1%), respectively. Five-year estimates for peri-implantitis were 5.4% (95% CI: 2–14.2%) and 9.4% (95% CI: 3.3–25.4%) at implant and prosthesis levels, respectively. Veneer fracture (5-year estimate: 10.3%; 95% CI: 3.9–26.6%) and screw loosening (5-year estimate: 8.2%; 95% CI: 3.9–17%) represented the most common complications, followed by loss of retention (5-year estimate: 5.7%; 95% CI: 1.9–16.5%) and abutment/screw fracture (5-year estimate: 2.1%; 95% CI: 0.9–5.1%). Implant fracture was rare (5-year estimate: 1.3%; 95% CI: 0.2–8.3%); no framework fracture was reported. Radiographic bone level changes did not yield statistically significant differences either at the prosthesis or at the implant levels when comparing ICFDPs with short-span implant-supported end-abutment fixed dental prostheses. Conclusions: ICFDPs represent a valid treatment modality; no detrimental effects can be expected on bone levels due to the presence of a cantilever extension per se. [ABSTRACT FROM AUTHOR]

Objective: Whereas an overdenture concept is generally accepted for the mandible, the outcome of this therapy for the maxilla remains less documented. This retrospective analysis evaluated the peri-implant parameters of implants supporting a ‘planned’ overdenture in the maxilla, and compared these data with those of an age-matched control group, with a fixed full dental prosthesis. Material and methods: All patients with an implant-supported overdenture in the maxilla from the Leuven University Hospital (at least 12 months in function) were recalled for a thorough examination. Forty-four patients (162 implants, Brånemark type) could be enrolled. Results: The mean loading time was 9 years (range: >1 to >20 years). The cumulative survival rate after 10 years of function was 99.3% if four to six interconnected implants supported the overdenture, but only 85.7% in case two non-connected implants were used as support. The marginal bone level in the former group remained stable, with changes comparable with those observed for implants supporting fixed full dental prostheses. Conclusions: These results fully support the overdenture treatment concept for the maxilla, at least when ≥4 splinted implants are used. [ABSTRACT FROM AUTHOR]

Aim: The aim of the present study was to analyze tissue reactions to plaque formation following ligature removal at commercially available implants exposed to experimental peri-implantitis. Material and methods: Six Labrador dogs about 1 year old were used. All mandibular premolars and the three anterior premolars in both sides of the maxilla were extracted. After 3 months four implants representing four different implant systems with different surface characteristics – implant group A (turned), B (TiOblast), C (sandblasted acid-etched; SLA) and D (TiUnite) – were placed in a randomized order in the right side of the mandible. Three months after implant installation experimental peri-implantitis was initiated by placement of ligatures in a submarginal position and plaque accumulation. At week 12, when about 40–50% of the supporting bone was lost, the ligatures were removed. During the subsequent 24-week period plaque accumulation continued. Radiographic and clinical examinations were performed during the ‘active breakdown’ period (plaque accumulation and ligatures) and the plaque accumulation period after ligature removal. The experiment was terminated at week 36. Results: The bone loss that took place during the ‘active breakdown’ period varied between 3.5 and 4.6 mm. The additional bone loss that occurred during the plaque accumulation period after ligature removal was 1.84 (A), 1.72 (B), 1.55 (C) and 2.78 mm (D). Conclusion: Spontaneous progression of experimentally induced peri-implantitis occurred at implants with different geometry and surface characteristics. Progression was most pronounced at implants of type D (TiUnite surface). [ABSTRACT FROM AUTHOR]

Objectives: The aim of the present study was to evaluate the outcome of immediate functional loading of implants in single-tooth replacement using two different installation procedures. Material and Methods: One hundred and fifty-one subjects, who required single-tooth rehabilitation in the area of 15–25 and 35–45, were enrolled in eight private clinics in Italy. The implant sites were randomly allocated to one of the following treatment groups. In the control group, in which a standard preparation procedure for implant placement and submerged healing of the implant was used, abutment connection and loading of the implants were performed 3 months after installation. In the test group 1, a standard preparation procedure for the implant placement and immediate functional loading of implant was carried out. In the test 2 group, however, a modified implant installation procedure (osteotome technique) was used followed by immediate functional loading of the implant. Clinical and radiographic examinations were performed at 3 and 12 months of follow-up at all sites. Results: Three implants (5.5%) from the test 2 group (osteotome preparation) and one (2%) from the test 1 group (conventional drill preparation) failed to integrate and were removed one and three months after implant installation. The mean marginal bone loss assessed at 12 months was 0.31 mm (test 1), 0.25 mm (test 2) and 0.38 mm (control) (no statistically significant differences were found between the three treatment groups.) Conclusion: It is suggested that immediate functional loading of implants that are placed with a conventional installation technique and with sufficient primary stability may be considered as a valid treatment alternative in a single-tooth replacement. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to describe the clinical characteristics at implants with a history of progressive bone loss. Material and methods: Eighty-two out of 184 previously identified subjects with a history of progressive bone loss volunteered for the study. Clinical assessments of plaque, bleeding on probing (BoP), probing pocket depth (PPD), suppuration following probing (Pus), presence of calculus on implants surfaces (Calc) and ‘recession’ i.e. the mucosal margin in level with or apical of the fixture/abutment junction were performed at the mesial, distal, buccal and lingual aspects of each implant and without removing the bridge constructions. Results: It was demonstrated that the frequencies of BoP, Pus, ‘recession’ and PPD≥6 mm were higher at implants with than without ‘progressive’ bone loss. In addition, smokers had larger numbers of affected implants than non-smokers, and the proportion of affected implants that exhibited Pus and PPD≥6 mm was higher in smokers than in non-smokers. The logistic regression analysis revealed that the findings of Pus, ‘recession’ and PPD≥6 mm at an implant in a smoking subject had a 69% accuracy in identifying the history of progressive bone loss. Conclusion: The results from this study demonstrate an association between clinical signs of pathology and bone loss at implants. It is recommended to include clinical assessments in the evaluation of implant therapy. [ABSTRACT FROM AUTHOR]

Objective: To assess the impact of overloading on peri-implant bone level and the bone-to-implant contact (BIC) in the presence of healthy or inflamed peri-implant tissues. Materials and methods: Four screw-shaped machined implants were placed bilaterally in the mandible of four beagle dogs and left submerged for 3 months. Prosthetic abutments were connected either in supra-occlusal contact with the opposite teeth (overloaded) or in infra-occlusal position (unloaded). In each dog, cotton floss ligatures were placed unilaterally around abutments to promote plaque accumulation; the contralateral side was brushed three times a week. There were four experimental sites, two implants in each: loaded uninflamed (LU), loaded inflamed (LI), unloaded uninflamed (UU), and unloaded inflamed (UI). Clinical and radiographic parameters were recorded at baseline and every 3 months throughout the observation period. At 12 months, the dogs were sacrificed and histomorphometric analysis was performed. Results: Implants with ligature-induced peri-implantitis presented high inflammatory indices throughout the observation period. Clinical parameters did not change from baseline for both LU and UU. Loading significantly increased the percentage of BIC (BIC%) ( P<0.05) and slightly increased crestal bone resorption, but not apical to the implant neck. Both LI and UI groups showed significant peri-implant bone loss ( P<0.01), mostly horizontal on the buccal aspect and angular on the lingual aspect, which exposed implant threads. Loading significantly ( P<0.05) increased implant thread exposure due to buccal and lingual vertical bone resorption. Conclusions: In the presence of uninflamed peri-implant mucosa, overloading of implants in the dog model increased BIC% and slightly reduced marginal bone level. However, resorption did not progress beyond the implant neck. Overloading aggravated the plaque-induced bone resorption when peri-implant inflammation was present. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to retrospectively analyze the potential influence of implant inclination on marginal bone loss at freestanding, implant-supported, fixed partial dentures (FPDs) over a 5-year period of functional loading. Material and methods: The material comprised 38 periodontally treated, partially dentate patients with a total of 42 free-standing FPDs supported by implants of the Astra Tech System®. Mesio-distal inclination of the implants in relation to a vertical axis perpendicular to the occlusal plane was measured with a protractor on standardized photographs of the master cast. The two tail quartiles of the distribution of the implants with regard to the implant inclination were defined as axial-positioned (mean 2.4°; range 0–4°) and non-axial-positioned implants (mean 17.1°; range 11–30°), respectively. For FPDs supported by two implants, both the mesial–distal and buccal–lingual inter-implant inclination was measured. The primary outcome variable was change in peri-implant bone level from the time of FPD placement to the 5-year follow-up examination. Comparison between axial- and non-axial-positioned implants was performed by the use of a Mann–Whitney U-test. Spearman's correlation analysis was used to analyze relationships between inter-implant inclination (mesial–distal and buccal–lingual) and 5-year bone level change on the FPD level. Results: The 5-year mean bone level change amounted to 0.4 mm (SD 0.97) for the axial and 0.5 mm (0.95) for non-axial-positioned implants ( P>0.05). For the FPDs supported by two implants, the mean inter-implant inclination was 9.2° (1–36°) in the mesial–distal direction and 6.7° (0–24°) in the buccal–lingual direction. Correlation analysis revealed lack of statistically significant correlation between inter-implant inclination (mesial–distal and buccal–lingual) and 5-year bone level change ( r=−0.19 and r=−0.32, respectively). Conclusion: The study failed to support the hypothesis that implant inclination has an effect on peri-implant bone loss. [ABSTRACT FROM AUTHOR]

A comparison between host response in teeth and dental implants was not made. Likewise, the association between host response and periodontal parameters has never been explored. The purpose of this study was to compare periodontal health around natural teeth and dental implants with different restorative platforms. Twenty-seven partially edentulous patients with dental implants, either external hex butt joint ( n=28) or tapered Morse ( n=45), were included in this study. Implants were in function for 1–6 years (mean 2.9). Plaque index (PI), gingival index (GI), probing depth (PD); and clinical attachment level (CAL), were recorded at final examination; alveolar bone loss (ABL) was measured at baseline and final examination using panoramic radiographs. Gingival crevicular fluid samples were obtained from the Ramfjord index teeth and all implants and assayed using enzyme-linked immunosorbent assay for prostaglandin E2 (PGE2), interleukin-1 (IL-1) and tumour necrosis factor α (TNFα). Differences between teeth and implants and between the two implant platforms were compared using Student's t-test. Correlations between cytokines, ABL and clinical parameters were analyzed using Pearson's co-efficient test. PI and GI were significantly higher in teeth than dental implants (1.2±0.5 vs. 0.8±0.5, P=0.0018; 1.2±0.3 vs. 1.1±0.3, P=0.048). Conversely, PD was deeper in implants (2.66±0.6 vs. 3.66±0.9, P=0.001). GI and PD around teeth and implants were positively associated ( R=0.561, P=0.0023; R=0.39, P=0.0452). Greater ABL was observed around dental implants (1.62±2.2 mm) compared with teeth (0.49±0.3 mm). A positive correlation was found between both IL-1 ( R=0.73, P=0.0064; R=0.52, P=0.0081) and TNFα ( R=0.64, P=0.0246; R=0.46, P=0.091) and ABL in teeth and implants. Both implant platforms were similar clinically and radiographically; however, TNFα (2.49±0.3 vs. 4.79±0.5, P=0.004) and IL-1 (24.52±7.3 vs. 45.41±9.9, P=0.095) were higher for the non-submerged implants. In conclusion, IL-1 and TNFα are sensitive markers of ABL around teeth and implants. The two dental implant platforms showed a similar clinical and radiographic response; however, the greater host response in the non-submerged implants might suggest future bone loss. [ABSTRACT FROM AUTHOR]