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To investigate survival rates, technical and biologic outcomes of buccally micro-veneered all-ceramic single implant crowns.Sixty subjects randomly received immediately or early placed implants. Crowns out of lithium-disilicate (n = 30) and zirconia-ceramic (n = 30) were bonded to titanium-base-abutments. Restorations were inspected at baseline (BL) and during follow-up visits (6, 12 months). Technical and biologic parameters were recorded. Data were analysed descriptively. Differences between groups were tested with Student's t-test. Paired T-test was used when comparing data from the same implant or tooth over time. Linear model repeated measures were used to test differences between materials over time. Differences in counts were evaluated using Pearson Chi-square test. The level of significance was at p .05.After a mean observation time of 13.2 ± 2.4 months, 54 restorations were re-examined. The implant survival rate was 98.3%, and the restoration survival rate was 100%. One early implant failure occurred. Two minor chippings occurred in lithium-disilicate restorations. No chippings or fractures occurred in any zirconia restorations at 1 year (0%). The technical complication rate was 3.7%, with 7.7% complications among the lithium-disilicate restorations and no differences between the two materials (p = .558). At 1-year follow-up, mean Bleeding on Probing (BOP) was higher at implants (0.27 ± 0.3) than adjacent teeth (0.17 ± 0.18) (p = .046) with no differences between materials (p = .36). Differences in pocket probing depth (PPD) between implants and adjacent teeth were significant (p .01). Jemt Index improved significantly from BL to 1-y-follow-up (p .001).Preliminary results were good, suggesting that the ceramic type does not impact technical and biologic parameters.

6. EAO Consensus Conference 2021, online, 11 Feb 2021 - 12 Feb 2021; Clinical oral implants research 32(S21), 336-341 (2021). doi:10.1111/clr.13797 special issue: "Special Issue: The 6th EAO Consensus Conference 2021 / edited by: Irena Sailer, Björn Klinge, Henning Schliephake", Published by Wiley-Blackwell, Oxford

Objectives: To test whether early implant placement with alveolar ridge preservation (ARP) results in different esthetic, clinical and patient-reported outcome measures (PROMs) compared with early implant placement without ARP. Material and methods: Seventy-five patients requiring single tooth extraction in the anterior maxilla were recruited. Following tooth extraction, the patients were randomly allocated to three groups: (a) ARP using demineralized bovine bone mineral containing 10% collagen (DBBM-C) covered by a collagen matrix (CM) (n = 25), (b) ARP using DBBM-C covered with a palatal graft (PG) (n = 25) and (c) spontaneous healing (control) (n = 25). Eight weeks after tooth extraction, a CBCT was taken and early implant placement was performed in all patients. Esthetic, clinical and PROMs were evaluated one year post-loading. Results: A total of 70 patients were available for re-examination at one year post-loading. The median mid-facial mucosal margin change amounted to −0.02 mm (IQR −0.27–0.46) in the CM group, −0.13 mm (IQR −0.44–0.25) in the PG group and −0.14 mm (IQR −0.29–0.07) in the control group, with no significant differences between the groups. Mean PES scores amounted to 7.0 ± 1.4 in the CM group, 7.1 ± 1.5 in the PG group and 7.3 ± 1.7 in the control group without significant differences between the groups. Plaque, bleeding on probing and probing depth did not differ between treatment groups. PROMs in general revealed no significant differences between the groups. Conclusion: Early implant placement with ARP using either a collagen matrix or a palatal graft rendered similar esthetic, clinical and PROMs to early implant placement without ARP. When a failing tooth can be replaced with an implant within 2 months after tooth extraction, the added value of ARP might be clinically negligible.

OBJECTIVES: To observe the sequential healing of lateral onlay grafts in terms of volumetric and histological changes when using different combinations of synthetic soft-type block bone and resorbable collagen membranes. MATERIALS AND METHODS: A lateral onlay graft procedure was applied at the chronic narrow alveolar ridge of the mandible in 15 beagle dogs. The groups were allocated as follows: (a) empty control; (b) onlay graft using soft-type block bone 1 (hydroxyapatite [HA]: β-tricalcium phosphate [β-TCP] = 15:85) and a non-cross-linked collagen membrane (MP-BG group); (c) onlay graft using soft-type block bone 2 (HA:β-TCP = 60:40) and a non-cross-linked collagen membrane (OC-BG group); and (d) onlay graft using soft-type block bone 1 (HA:β-TCP = 15:85) and a cross-linked collagen membrane (MP-CM group). Volumetric and histomorphometric analyses were performed at 4, 8 and 16 weeks postoperatively. RESULTS: No clinical complications occurred in any of the groups. The OC-BG group showed significantly larger total augmented volumes than the control and MP-BG groups after 8 and 16 weeks. The areas of new bone were significantly larger in the OC-BG group than the other groups at 16 weeks. The horizontal thickness of the augmented ridge was significantly larger in the OC-BG group than in the control group at 16 weeks. CONCLUSION: The OC-BG group showed superior volume maintenance and osteogenic potential for up to 16 weeks compared to the other groups in an onlay graft model of the dog mandible despite the displacement of the bone graft.

Aim: To test whether or not buccal vertical bone dehiscences (≤5 mm) around posterior implants left for spontaneous healing (SH) result in the same clinical and radiologic outcome as dehiscences treated with guided bone regeneration (GBR) at 7.5 years after implant placement (IMPL). Materials and methods: Twenty-two patients receiving 28 posterior implants with a small non-contained buccal bone dehiscence (≤5 mm) were randomly assigned to the SH or the GBR group. Implants were loaded at 6 months. Clinical parameters (probing depths, sulcus bleeding index, plaque index) and approximal marginal radiographic bone levels were assessed regularly up to at least 6.8 years. The vertical extension of the dehiscences was measured clinically at IMPL and abutment connection and radiographically on cone beam computed tomographys at a mean follow-up time of 7.5 years. Results: Twenty patients with a total of 26 implants were recalled at 7.5 years (9.1% dropout). The implant/crown survival rates were 100% in both groups. Stable peri-implant tissues were observed in both groups showing only minimal signs of inflammation. During the entire study period (IMPL-7.5-year follow-up), the median buccal vertical bone gain measured 1.61 mm for the GBR group and 0.62 for the SH group showing no significant difference between the groups. Also, at 7.5 years, the median approximal marginal bone levels (GBR: 0.53; SH: 0.68) were not significantly different between the two groups (p = .61) while the remaining median buccal vertical dehiscences were larger in the SH group (2.51 mm) compared to the GBR group (1.66 mm; p = .02). Conclusions: Implants with small non-contained buccal bone dehiscences exhibited high implant survival rates and healthy peri-implant tissues at 7.5 years. In the GBR group, the buccal vertical bone levels were higher compared to the SH group but remained stable over the entire study period for both treatments. Keywords: bone substitute; dental implant; guided bone regeneration; small buccal defects; spontaneous healing. © 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

To assess long-term outcomes of implants placed in conjunction with guided bone regeneration (GBR) with or without recombinant human bone morphogenetic protein-2 (rhBMP-2).Eleven patients with at least two lateral bone defects (split-mouth design) received a total of 34 implants. The defects were treated with a xenogenic bone substitute with (test) or without (control) rhBMP-2 and covered with a collagen membrane. Eight patients could be reexamined after at least 17 years. Wilcoxon signed-rank tests were performed to assess differences between test and control groups.The implant survival rate was 100% for all test and control sites. Mean marginal bone levels were 2.51 mm (SD ±1.64) (mesial test), 1.83 mm (SD ±0.93) (mesial control) (p = .055), 2.36 mm (SD ±1.70) (distal test), and 2.13 mm (SD ±0.84) (distal control) (p = 1.000). Compared with the mean values at baseline, a mean bone loss of 1.16 mm (SD ±1.60) (test) and 0.70 mm (SD ±1.02) (control) was found. The mean buccal bone gain after 17 years was 5.38 mm (test) and 3.14 mm (control) based on the comparison between the measurements at the cone beam CT after 17 years and the data from the intraoperative measurements at baseline. Further, mean values for (i) bone thickness ranged from 1.36 to 3.09 mm (test) and 1.18 to 3.39 mm (control) and for (ii) mucosal thickness of 1.24 mm (test) and 1.26 mm (control).Implants placed in conjunction with GBR applying a xenogenic bone substitute and a collagen membrane with and without the addition of rhBMP-2 demonstrate excellent clinical and radiographic results after at least 17 years.

AIM The aim was to evaluate the performance of implants placed with simultaneous guided bone regeneration (GBR) using resorbable or nonresorbable membranes compared to implants placed in pristine bone without bone regeneration after an observation period of 22-24 years. MATERIAL AND METHODS The patient cohort of this clinical trial was treated from 1994 to 1996. Dehiscence defects were treated with GBR by either using resorbable collagen membranes (BG) or nonresorbable ePTFE membranes (GT). Implants placed in pristine bone served as a control (CT). Clinical parameters, marginal bone levels, and technical outcomes were evaluated following restoration placement and at the present follow-up. A 3D radiographic analysis was conducted in order to assess buccal and oral bone dimensions. Implant survival was assessed with Kaplan-Meier analysis and a frailty model (level of significance 5%). RESULTS Out of the originally 72 patients (mean age 75.4 ± 15.70 years) with 265 implants, 39 patients with 147 implants were included in the study after a median period of 23.5 years. Implant survival was 89.3% in group BG (n = 100), 90.2% in group GT (n = 37), and 93.8% in group CT (n = 105), without significant differences (Frailty proportional hazard model p = .79). Smoking had a negative effect on survival (p = .0122). Mean vertical marginal bone levels were -2.3 ± 1.4 mm (BG, n = 59), -3.0 ± 1.5 mm (GT, n = 21), and -2.3 ± 1.6 mm (CT, n = 52). The vertical buccal bone levels were -3.0 ± 1.9 mm (BG, n = 57), -3.5 ± 2.2 mm (GT, n = 21), and -2.6 ± 1.8 mm (CT, n = 49), without significant differences. CONCLUSION Implant placement with GBR procedures provides treatment outcomes with favorable implant survival rates (89.3%-93.8%) after 23.5 years. Smoking, however, affected implant survival negatively.

OBJECTIVES: To test whether or not the use of a xenogeneic block loaded with rhBMP-2 results in superior radiological and profilometric outcomes compared to an autogenous bone block. MATERIALS AND METHODS: Twenty-four patients randomly received a xenogeneic block loaded with rhBMP-2 (test) or an autogenous bone block (control) for primary augmentation. The ridge width (RW) was evaluated by means of a CBCT scan after augmentation surgery and at 4 months, prior to implant placement. Surface scans were taken prior to augmentation and at 4 months for profilometric analyses. Data were analyzed with Wilcoxon-signed rank test, Mann-Whitney test, or nonparametric ANOVA models. RESULTS: The median RW after augmentation amounted to 7.13 mm (Q1 = 6.02; Q3 = 8.47) for test and 6.86 mm (Q1 = 5.99; Q3 = 8.95) for control. During 4 months of healing, the total RW decreased statistically significantly and measured 5.35 mm (Q1 = 4.53; Q3 = 6.7) for test and 5.15 mm (Q1 = 3.57; Q3 = 7.24) for control (p = 0.0005). The differences between the groups were not statistically significant (p > 0.5899). The buccal soft tissue contour slightly increased for test (0.83 mm; Q1 = 0.62; Q3 = 1.87) and control (1.16 mm; Q1 = 0.50; Q3 = 1.44). CONCLUSIONS: Both treatment modalities successfully increased the ridge width to a similar extent. The shrinkage during healing was not greater in the test than in the control group. The impact of hard tissue augmentation on the soft tissue contour was, however, minimal.

OBJECTIVES To assess survival/success rates and patient-reported outcome of zirconia-based posterior single crowns (SCs) supported by zirconia implants in a prospective two-center study after five years of observation. MATERIAL AND METHODS Forty-five patients were restored with 45 zirconia implant-supported posterior SCs composed of zirconia frameworks hand-layered with a leucite-reinforced feldspathic ceramic. Survival rates of SCs were assessed and technical success was evaluated according to modified United States Public Health Care (USPHS) criteria. Furthermore, patient-reported outcome measures (PROMs) were assessed by applying visual analog scales (VAS). Wilcoxon matched-pairs signed-rank test, mixed-effects ordered logistic regression, and linear mixed models were used to evaluate time effects on response variables. RESULTS Forty patients were available after a mean observation period of 61.0 ± 1.4 months. One SC had to be replaced, resulting in a Kaplan-Meier (KM) survival estimate for the SCs of 97.5 ± 2.47%. Since nine reconstructions showed at least in one category a major deviation from the ideal (five major chippings, four with increased occlusal roughness, one significant crevice, and one pronounced over-contouring), the KM success estimate was 79.3 ± 5.8%. Incidence of chipping (n = 19) and occlusal roughness (n = 35) was frequent (p

OBJECTIVE To systematically review the dental literature for clinical studies reporting on production time, effectiveness and/or costs of additive and subtractive computer-aided manufacturing (CAM) of implant prostheses. MATERIALS AND METHODS A systematic electronic search for clinical studies from 1990 until June 2020 was performed using the online databases Medline, Embase and Cochrane. Time required for the computer-aided design (CAD) process, the CAM process, and the delivery of the CAD-CAM prostheses were extracted. In addition, articles reporting on the effectiveness and the costs of both manufacturing technologies were included. RESULTS Nine clinical studies were included reporting on subtractive CAM (s-CAM; 8 studies) and additive CAM (a-CAM; 1 study). Eight studies reported on the s-CAM of prosthetic and auxiliary components for single implant crowns. One study applied a-CAM for the fabrication of an implant bar prototype. Time was provided for the CAD process of implant models (range 4.9-11.8 min), abutments (range 19.7-32.7 min) and crowns (range 11.1-37.6 min). The time for s-CAM of single implant crown components (abutment/crown) ranged between 8.2 and 25 min. Post-processing (e.g. sintering) was a time-consuming process (up to 530 min). At delivery, monolithic/veneered CAD-CAM implant crowns resulted in additional adjustments chairside (51%/93%) or labside (11%/19%). CONCLUSIONS No scientific evidence exists on production time, effectiveness and costs of digital workflows comparing s-CAM and a-CAM. For both technologies, post-processing may substantially contribute to the production time. Considering effectiveness, monolithic CAD-CAM implant crowns may be preferred compared to veneered CAD-CAM crowns.

Objectives: To compare two ridge preservation techniques and spontaneous healing in terms of hard and soft tissue changes 2 months after tooth extraction. Material and methods: The study was designed as a randomized controlled trial and included 75 patients. After single tooth extraction in the maxillary incisor/premolar area, patients were randomly allocated to one of the following groups: (a) ridge preservation with a xenogeneic bone substitute covered with a collagen matrix (CM-group), (b) ridge preservation with a xenogeneic bone substitute covered with a free palatal graft (PG-group) or (c) spontaneous healing (control). Eight weeks after tooth extraction, implants were placed and clinical, profilometric and radiographic evaluations were performed. In addition, the need for further guided bone regeneration (GBR) at implant placement was assessed. The differences between the treatment groups were compared with the One-way ANOVA or Kruskal–Wallis test with the corresponding post hoc analysis. The proportions of the categorical parameters were compared with the Fisher´s exact test. Results: Seventy-five patients underwent early implant placement 8 weeks after tooth extraction and were evaluated. CM-group (−0.9 SD 0.6 mm) and PG-group (−1.0 SD 0.8 mm) showed less horizontal bone resorption compared to the control group (−3.2 SD 2.1 mm) (p

OBJECTIVES The aim of this systematic review was to assess clinical evidence on adverse effects of osseointegrated implants placed among natural teeth of a residual dentition. METHODS Seven databases were searched without restrictions up to January 2018 for clinical studies on implant infraposition (IIP) or proximal contact point (PCP) loss to the adjacent teeth. After duplicate selection, data extraction, and risk of bias assessment according to the Cochrane guidelines, random-effects meta-analyses of odds ratios (OR) or mean differences (MD) and their 95% confidence intervals (CI) were performed, followed by meta-regression and sensitivity analyses. RESULTS A total of 27 nonrandomized studies with 1,572 patients (mean age 42.2 years/51.2% female) followed up to 18.5 years after implant placement were included. The pooled %prevalence of IIP was 50.5% (nine studies; 95% CI = 26.3-74.5%), and the pooled IIP extent was 0.58 mm (six studies; 95% CI = 0.33-0.83 mm), while IIP > 1 mm was seen for 20.8% of placed implants (five studies; 95% CI = 8.3-37.1%), and male patients were less prone to IIP than female patients (three studies; OR = 0.30; 95% CI = 0.10-0.88; p = 0.03). The pooled %prevalence of PCP loss was 46.3% (nine studies; 95% CI = 32.3-60.6%), with increase through observation time (two studies; OR = 1.09; 95% CI = 1.03-1.16; p = 0.004) and predilection for mesial PCPs (five studies; OR = 2.25; 95% CI = 1.06-4.77; p = 0.03). However, the quality of evidence was very low due to bias. CONCLUSIONS Patients and doctors need to be aware that long-term adverse effects of dental implants among natural teeth can be observed in terms of IIP and PCP loss to the adjacent teeth.

OBJECTIVES: This publication reports the EAO Workshop group-2 discussions and consensus statements which provided the scientific evidence on the influence of biological parameters on implant-related clinical outcomes. MATERIAL AND METHODS: The first publication was a systematic review on the biological effects of abutment material on the stability of peri-implant marginal bone levels and the second, a critical narrative review on how peri-implant diagnostic parameters correspond with long-term implant survival and success. The group evaluated the content of both publications, made corrections and recommendations to the authors and agreed on the consensus statements, clinical recommendations and recommendations for future research, which are described in this consensus report. RESULTS: Tested abutment materials can be considered appropriate for clinical use according to the observation period studied (mean 3.5 years). Mean peri-implant bone loss and mean probing pocket depths are not adequate outcomes to study the prevalence of peri-implantitis, while the reporting of frequency distributions is considered more appropriate. CONCLUSIONS: Titanium is currently considered the standard of care as abutment material, although other materials may be more suitable for aesthetic locations. Peri-implantitis should be diagnosed through composite evaluations of peri-implant tissue inflammation and assessment of marginal bone loss with different thresholds.

OBJECTIVES To assess the early histological, microbiological, radiological, and clinical response to cemented and screw-retained all-ceramic single-tooth implant-supported reconstructions. MATERIALS AND METHODS Patients with single-tooth implants were randomly allocated to receive a cemented lithium disilicate crown on a customized zirconia abutment (CEM) or a screw-retained crown with a directly veneered zirconia abutment (SCREW). At the screening visit, at crown insertion and at the 6-month follow-up, clinical parameters were measured at the implant and the contralateral tooth. Marginal bone levels, technical parameters, and esthetic outcomes were measured at the implants. At the 6-month follow-up, a microbiological test was performed and a soft tissue biopsy was harvested at the implants for histological analysis. Inflammatory cells and fibroblasts/-cytes were analyzed at the level of the sulcular epithelium, junctional epithelium, and connective tissue. The histological parameters were analyzed by means of a linear mixed model. RESULTS Thirty-three patients completed the study, and implant and crown survival rates were 100% at 6 months. Histologically, the number of inflammatory cells tended to be higher in group CEM (p > 0.05). Moreover, significantly less inflammatory cells and fibroblasts/-cytes were found in the sulcular epithelium compared to the junctional epithelium and supracrestal connective tissue (p < 0.001). Four patients were tested positive for periodontal marker pathogens at the 6-month follow-up, and three of them belonged to group CEM. From crown insertion to the 6-month follow-up, median marginal bone levels changed only minimally and measured 0.31 and 0.32 mm in group CEM and 0.47 and 0.36 mm in group SCREW, respectively. Clinical and esthetic parameters remained stable over time and were comparable between natural teeth and implants as well as between the groups. CONCLUSIONS Cemented reconstructions were associated with more inflammatory cells, and more patients were diagnosed with periodonto-pathogens. Both types of reconstructions resulted in similar radiological (marginal bone levels) and clinical outcomes (bleeding on probing and probing depth).

OBJECTIVES To assess two- and three-dimensional changes of the peri-implant tissues as well as clinical, biological, and radiological outcomes of implants having been treated with resorbable or nonresorbable membranes at 3 years. MATERIALS AND METHODS Twenty-three patients were re-examined after having received a single-tooth implant in the esthetic zone in conjunction with guided bone regeneration (GBR) using either a resorbable (RES) or a titanium-reinforced nonresorbable membrane (N-RES) and demineralized bovine bone mineral. Volumetric and linear as well as clinical and radiographic measurements were performed at crown insertion (baseline), at 1 year (FU-1) and 3 years (FU-3). Statistics were performed by means of parametric and nonparametric tests. RESULTS Minor, but ongoing buccal volume loss was observed in both groups during the 3-year follow-up. A slightly higher volume loss was observed in group RES (-0.22 mm) compared to N-RES (-0.14 mm) at 1 year (FU-1), but aligned at 3 years (FU-3) RES (-0.30 mm) N-RES (-0.32 mm). All changes over time were statistically significantly different within (p .05). Stable median interproximal bone levels after 3 years (FU-3); 0.26 mm (0.04; 0.36) (RES) and 0.14 mm (0.08; 0.20) (N-RES) and healthy tissues (BOP, PD) were obtained with both membranes. CONCLUSIONS Both treatment modalities resulted in minor, but ongoing contour changes of the peri-implant tissues. Stable interproximal bone levels and healthy tissues can be obtained with membranes up to 3 years.

BACKGROUND There is limited knowledge regarding the strength of zirconia abutments with internal and external implant abutment connections and zirconia abutments supported by a titanium resin base (Variobase, Straumann) for narrow diameter implants. OBJECTIVES To compare the fracture strength of narrow diameter abutments with different types of implant abutment connections after chewing simulation. MATERIAL AND METHODS Hundred and twenty identical customized abutments with different materials and implant abutment connections were fabricated for five groups: 1-piece zirconia abutment with internal connection (T1, Cares-abutment-Straumann BL-NC implant, Straumann Switzerland), 1-piece zirconia abutment with external hex connection (T2, Procera abutment-Branemark NP implant, Nobel Biocare, Sweden), 2-piece zirconia abutments with metallic insert for internal connection (T3, Procera abutment-Replace NP implant, Nobel Biocare), 2-piece zirconia abutment on titanium resin base (T4, LavaPlus abutment-VarioBase-Straumann BL-NC implant, 3M ESPE, Germany) and 1-piece titanium abutment with internal connection (C, Cares-abutment-Straumann BL-NC implant, Straumann, Switzerland). All implants had a narrow diameter ranging from 3.3 to 3.5 mm. Sixty un-restored abutments and 60 abutments restored with glass-ceramic crowns were tested. Mean bending moments were compared using ANOVA with p-values adjusted for multiple comparisons using Tukey's procedure. RESULTS The mean bending moments were 521 ± 33 Ncm (T4), 404 ± 36 Ncm (C), 311 ± 106 Ncm (T1) 265 ± 22 Ncm (T3) and 225 ± 29 (T2) for un-restored abutments and 278 ± 84 Ncm (T4), 302 ± 170 Ncm (C), 190 ± 55 Ncm (T1) 80 ± 102 Ncm (T3) and 125 ± 57 (T2) for restored abutments. For un-restored abutments, C and T4 had similar mean bending moments, significantly higher than those of the three other groups (p

Objectives Working Group 2 at the 2nd Consensus Meeting of the Osteology Foundation had a focus on the influence of vertical implant placement on papilla height at single implants adjacent to teeth and on the inter-implant mucosa fill at two adjacent implants in the anterior maxilla. Materials and methods Two systematic reviews were prepared in advance of the consensus meeting. Due to the heterogeneity among the studies with regard to study design, study population, method of assessment, meta-analyses were not possible. Consensus statements, clinical recommendations, and implications for future research were based on structured group discussions until consensus was reached among the entire expert group. Results The systematic review about single-tooth implants included a total of 12 studies demonstrating that the vertical distance from the crestal bone level to the base of the interproximal contact point varied considerably from 2 mm up to 11 mm, and a partial or complete papilla fill was reached in 56.5% to 100% of the cases. For the systematic review regarding two adjacent implants, only four studies reported on horizontal inter-implant distances which ranged between 2.0 and 4.0 mm. More than half of the papilla presence was indicated in 21% to 88.5% of the cases. Conclusions It was concluded that for single-tooth implants, the papilla height between an implant and a tooth is predominantly dependent on the clinical attachment level of the tooth. In cases with two adjacent implants, it was concluded that it is not possible to define the optimal horizontal distance between two adjacent implants restored with fixed dental prosthess.

Objectives The goal of Working Group 1 at the 2nd Consensus Meeting of the Osteology Foundation was to comprehensively assess the effects of soft tissue augmentation procedures on peri-implant health or disease. Materials and methods A systematic review and meta-analysis on the effects of soft tissue augmentation procedures included a total of 10 studies (mucosal thickness: n = 6; keratinized tissue: n = 4). Consensus statements, clinical recommendations, and implications for future research were based on structured group discussions and a plenary session approval. Results Soft tissue grafting to increase the width of keratinized tissue around implants was associated with greater reductions in gingival and plaque indices when compared to non-augmented sites. Statistically significant differences were noted for final marginal bone levels in favor of an apically positioned flap plus autogenous graft vs. all standard-of-care control treatments investigated. Soft tissue grafting (i.e., autogenous connective tissue) to increase the mucosal thickness around implants in the aesthetic zone was associated with significantly less marginal bone loss over time, but no significant changes in bleeding on probing, probing depths, or plaque scores when compared to sites without grafting. Conclusions The limited evidence available supports the use of soft tissue augmentation procedures to promote peri-implant health.

Aim To test whether guided bone regeneration (GBR) of peri-implant defects at zirconia (ZrO2) implants differs from GBR at titanium (Ti) implants regarding the bone integration of the implant and of the grafting material. Materials and methods Maxillary premolars and molars were extracted in seven dogs. After 5 months, four semi-saddle bone defects were created in each maxilla. Implant placement and simultaneous GBR were performed using the following randomly assigned modalities: (1) ZrO2 implant + deproteinized bovine bone mineral (DBBM) granules + a collagen membrane (CM), (2) ZrO2 implant + DBBM with 10% collagen matrix + CM, (3) ZrO2 implant + DBBM block + CM, and (4) Ti implant + DBBM granules + CM. After 3 months, one central histological section of each site was prepared. Histomorphometrical assessments were performed evaluating the augmented area (AA) within the former bone defect (primary outcome), the area of new bone (NB), bone substitute (BS), and non-mineralized tissue (NMT) within AA in mm2. In addition, the distance between the most coronal bone-to-implant contact and the margin of the former bone defect (fBIC-DEF), and the bone-to-implant contact fraction (BIC) were measured in mm. Results AA measured 8.6 ± 4.0 mm2 for ZrO2 implant + DBBM granules, 4.7 ± 1.6 mm2 for ZrO2 implant + DBBM-collagen, 5.1 ± 1.9 mm2 for ZrO2 implant + DBBM block, and 7.6 ± 2.8 mm2 for Ti implant + DBBM granules. There were no statistically significant differences between the treatment modalities (P > 0.05). NB reached 2.0 ± 1.7 mm2 for ZrO2 implant + DBBM granules, 0.9 ± 0.9 mm2 for ZrO2 implant + DBBM-collagen, 2.1 ± 0.9 mm2 for ZrO2 implant + DBBM block, and 0.8 ± 0.6 mm2 for Ti implant + DBBM granules. fBIC-DEF amounted to 2.1 ± 1.7 mm2 for ZrO2 implant + DBBM granules, to 2.7 ± 1.1 mm2 for ZrO2 implant + DBBM-collagen, to 2.9 ± 1.2 mm2 for ZrO2 implant + DBBM block, and to 3.4 ± 0.4 mm2 for Ti implant + DBBM granules. BIC measured 70 ± 19% for ZrO2 implant + DBBM granules, 69 ± 22% for ZrO2 implant + DBBM-collagen, 77 ± 30% for ZrO2 implant + DBBM block, and 66 ± 27% for Ti implant + DBBM granules. Conclusions The findings of the present pilot study suggest that zirconia and titanium implants grafted with DBBM granules and covered with a collagen membrane do not perform differently regarding the augmented ridge contour, the NB formation, and the implant osseointegration.

OBJECTIVE: To evaluate the healing after elevation of the sinus mucosa when a collagen membrane was placed between the sinus mucosa and a xenograft used as filler. MATERIALS AND METHODS: Eighteen rabbits were used. Sinus mucosa elevation was performed bilaterally, and a collagen membrane was applied subjacent to the sinus mucosa only at a randomly selected test site. At both sites, a collagenated corticocancellous porcine bone was placed within the elevated space and the access window was covered with a collagen membrane. The animals were sacrificed after 2, 4, and 8 weeks of healing, six animals for group. Ground sections were prepared. RESULTS: At the histomorphometric evaluation, the elevated area after 2 and 8 weeks was 11.8 and 8.8 mm(2) at the test, and 10.0 and 5.3 mm(2) at the control sites, respectively. The available area was obtained subtracting the remaining area occupied by the membrane from the elevated area and, after 8 weeks, was 6.7 +/- 0.9 mm(2) . After 8 weeks of healing, the mineralized new bone within the elevated space was 18.2 +/- 5.5% at the test and 26.7 +/- 7.7% at the control sites. Within the available space at the test site, the percentage was 27.3 +/- 7.0% after 8 weeks of healing. At 2 and 8 weeks of healing, within the elevated space, the xenograft proportion was 30.9 +/- 4.4% and 6.9 +/- 2.8% at the test, and 35.2 +/- 7.3% and 9.6 +/- 4.9% at the control sites, respectively. CONCLUSIONS: The placement of a collagen membrane subjacent the sinus mucosa did not reveal any major morphometric difference. The collagen membrane was not completely resorbed after 8 weeks.

To test whether or not a one- (S1) and a two-piece (S2) dental implant systems render the same biological, technical, and esthetic outcomes regarding implants and implant-supported reconstructions over an observation period of 4 to 6 years.Sixty patients were randomly assigned to receive S1 or S2 implants. The implants were restored with either fixed or removable prostheses. The insertion of the final reconstruction was chosen as baseline. One-year and 4- to 6-year (FU-5) measurements included biological (e.g. marginal bone level, probing pocket depth, peri-implant mucositis, and peri-implantitis), technical (e.g. fracture or loosening of prosthetic screws, fracture or loosening of abutments, fracture of framework, and/or veneering ceramic (minor, major), loss of retention for cemented restorations), and esthetic parameters (visibility of the crown margin, shimmering of the implant through the mucosa, the level of the facial margo mucosae compared to the contralateral tooth or implant site and the modified papilla index) for implants and reconstructions. Survival and success rates of implants and reconstructions were calculated. Because of the asymmetric data distributions, nonparametric statistical methods were applied.The implant-based analysis revealed a cumulative implant survival rate of 97.9% (S1: 96.6%; S2: 98.9%) at FU-5. The median marginal bone level for group S1 changed from 0.51 mm at baseline to 0.49 mm at FU-5 and for group S2 from 1.02 mm to 1.35 mm (P 0.001). Patient-level analyses demonstrated a frequency of peri-implant mucositis of 7.7% (S1) and 10.0% (S2) and for peri-implantitis of 7.7% (S1) and 13.3% (S2) at FU-5. The patient-based cumulative implant survival rate was 94.6% (S1: 92.3%; S2: 96.7%). The overall patient-based biological complication rate amounted to 15.4% (S1) and to 23.3% (S2) (P = 0.517), whereas the overall technical complication rates were 30.8% (S1) and 13.3% (S2) (P = 0.349). The prosthetic survival rates were 93.1% for S1 and 100% for S2 (P 0.05).Both implant systems reveal high survival rates on the implant and prosthetic level. Apart from marginal bone-level changes, biological and technical outcomes did not reveal significant differences between the two implant systems.

OBJECTIVES The objective of this systematic review was to assess the 5-year and 10-year survival of resin-bonded fixed dental prostheses (RBBs) and to describe the incidence of technical and biological complications. MATERIALS AND METHODS An electronic MEDLINE search complemented by manual searching was conducted to identify prospective and retrospective cohort studies and case series on RBBs with a mean follow-up time of at least 5 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data extraction were performed independently by two reviewers. Failure and complication rates were analyzed using robust Poisson regression models to obtain summary estimates of 5- and 10-year proportions. RESULTS The search provided 367 titles and 87 abstracts. Full-text analysis was performed for 22 articles resulting in seven studies that met the inclusion criteria. Five articles were found through manual search, and 17 studies were provided from (Pjetursson et al. 2008, Clinical Oral Implants Research, 19, 131), resulting in an overall number of included studies of 29. Meta-analysis of these studies reporting on 2300 RBBs indicated an estimated survival of resin-bonded bridges of 91.4% (95 percent confidence interval [95% CI]: 86.7-94.4%) after 5 years and 82.9% (95% CI: 73.2-89.3%) after 10 years. A significantly higher survival rate was reported for RBBs with zirconia framework compared with RBBs from other materials. RBBs with one retainer had a significantly higher survival rate (P < 0.0001) and a lower de-bonding rate (P = 0.001) compared with RBBs retained by two or more retainers. Moreover, the survival rate was higher for RBBs inserted in the anterior area of the oral cavity compared with posterior RBBs. The most frequent complications were de-bonding (loss of retention), which occurred in 15% (95% CI: 10.9-20.6%) and chipping of the veneering material that was reported for 4.1% (95% CI: 1.8-9.5%) of the RBBs over an observation period of 5 years. CONCLUSION Despite the high survival rate of RBBs after 5 and 10 years, technical complications like de-bonding and minor chipping were frequent. RBBs with zirconia framework and RBBs with one retainer tooth showed the highest survival rate.

Objectives To assess the potential trends for the year 2030 in dental implant dentistry in Europe using the Delphi methodology. Material and methods A steering committee and a management team of experts in implant dentistry were created and validated a questionnaire including 60 questions, divided in eight topics. The survey was conducted in two rounds using an anonymous questionnaire, which provided the participants in the second round with the results of the first. Each question had three possible answers, and the results were expressed as percentages. Results A total of 138 experts were invited to participate in the survey. From all the invited experts, 52 answered in both the first and second rounds. Three different consensus categories were established based on the percentage of agreement: no consensus (

Objectives To test whether or not one of two biological mediators (recombinant human bone morphogenetic protein-2 (rhBMP-2) and recombinant human platelet-derived growth factor (rhPDGF-BB)) is superior to the other and compared with control groups for bone regeneration around implants based on histomorphometrical outcome measures. Materials and methods Box-type defects (10 × 5 × 5 mm) were prepared on the buccal sides of the left and right edentulous ridge in ten mongrel dogs. Implants were placed at each site, the defects either received (i) bovine-derived particulated bone mineral (DBBM) mixed with rhBMP-2 and a collagen membrane (CM) (DBBM/BMP-2), (ii) DBBM mixed with rhPDGF-BB and CM (DBBM/PDGF), (iii) DBBM and CM (DBBM) and (iv) empty control (control). Animals were euthanized post-surgery at 8 weeks and 16 weeks. Histomorphometrical analyses were performed. Results The mean percentages of regenerated area within total defect area amounted to 56.95% for DBBM/BMP-2, 48.86% for DBBM/PDFG, 33.44% for DBBM and 1.59% for control at 8 weeks, and 26.79% for DBBM/BMP-2, 23.78% for DBBM/PDFG, 30.21% for DBBM and 5.07% for control at 16 weeks with no statistically significant differences between the groups (P > 0.05). The mean amount of regenerated bone was 26.97% for DBBM/BMP-2, 22.02% for DBBM/PDFG, 5.03% for DBBM and 1.25% for control at 8 weeks, and at 16 weeks, these values were lower in the two groups with biological mediators (DBBM/BMP-2 = 13.35%; DBBM/PDGF = 6.96%) and only slightly increased in group DBBM (10.68%) and the control group (4.95%) compared with 8 weeks. The first bone-to-implant contact values on the buccal side were minimal for DBBM/BMP-2 (0.57 mm) and maximal for control (3.72 mm) at 8 weeks. Conclusions The use of biological mediators (rhBMP-2 and rhPDGF-BB) can increase the amount of bone regeneration at dehiscence-type defects compared with controls at 8 weeks, but not at 16 weeks due to enhanced hard tissue remodeling processes.

PURPOSE To test whether or not one of two membranes is superior for peri-implant-guided bone regeneration in terms of clinical and histologic outcomes. MATERIAL AND METHODS In 27 patients, 27 two-piece dental implants were placed in single-tooth gaps in the esthetic area. Buccal dehiscence and/or fenestration-type defects were regenerated using demineralized bovine bone mineral and randomly covered with either a resorbable membrane (RES) or a titanium-reinforced non-resorbable membrane (N-RES). Clinical measurements included vertical defect resolution and the horizontal thickness of regenerated bone at implant placement and at 6 months. Statistics were performed by means of nonparametric testing. RESULTS The remaining mean vertical defect measured 4 mm (±2.07) (RES) and 2.36 mm (±2.09) (N-RES) (P = 0.044) at baseline and 0.77 mm (±0.85) (RES) and 0.21 mm (±0.80) (N-RES) (P = 0.021) at re-entry. This translated into a defect resolution of 85% (RES) and 90.7% (N-RES) (P = 0.10). The horizontal thickness after augmentation measured 3.46 mm (±0.52) (RES) and 2.82 mm (±0.50) (N-RES) (P = 0.004). The mean loss in horizontal thickness from baseline to re-entry measured 2.23 mm (SD ±1.21) (RES) and 0.14 mm (±0.79) (N-RES) (P = 0.017). The horizontal changes in thickness at the implant shoulder level were statistically significant between the groups (P = 0.0001). CONCLUSIONS Both treatment modalities were clinically effective in regenerating bone as demonstrated by a similar horizontal thickness and vertical defect fill at 6 months. The N-RES group exhibited significantly less horizontal bone thickness reduction from baseline to follow-up.

OBJECTIVE To test the accuracy of measurement of interproximal peri-implant bone defects at titanium (Ti) and zirconium dioxide (ZrO ) implants by digital periapical radiography (PR) and cone beam computed tomography (CBCT). MATERIAL AND METHODS A total of 18 models, each containing one Ti and one ZrO implant, were cast in dental stone. Six models each were allocated to following defect groups: A-no peri-implant defect, B-1 mm width defect, C-1.5 mm width defect. The defect width was measured with a digital sliding caliper. Subsequently, the models were scanned by means of PR and CBCT. Three examiners assessed the defect width on PR and CBCT. Wilcoxon signed-rank test and Wilcoxon rank sum test were applied to detect differences between imaging techniques and implant types. RESULTS For PR, the deviation of the defect width measurement (mm) for groups A, B, and C amounted to 0.01 ± 0.03, -0.02 ± 0.06, and -0.00 ± 0.04 at Ti and 0.05 ± 0.02, 0.01 ± 0.03, and 0.09 ± 0.03 at ZrO implants. The corresponding values (mm) for CBCT reached 0.10 ± 0.11, 0.26 ± 0.05, and 0.24 ± 0.08 at Ti and 1.07 ± 0.06, 0.64 ± 0.37, and 0.54 ± 0.17 at ZrO implants. Except for Ti with defect A, measurements in PR were significantly more accurate in comparison to CBCT (p ≤ 0.05). Both methods generally yielded more accurate measurements for Ti than for ZrO . CONCLUSIONS The assessment of interproximal peri-implant defect width at Ti and ZrO implants was more accurate in PR in comparison to CBCT. Measurements in CBCT always led to an overestimation of the defect width, reaching clinical relevance for ZrO implants.

OBJECTIVE To calculate the precision of the implant analog position in digital models generated from different computer-assisted design and computer-assisted manufacturing (CAD-CAM) systems compared to gypsum models acquired from conventional implant impressions. MATERIALS AND METHODS In five patients in need of a single implant crown, a within-subject comparison was performed applying four different manufacturing processes for the implant model. Each implant was scanned with three different intraoral scanners: iTero Cadent (ITE), Lava True Definition (LTD), and Trios 3Shape (TRI). All digital implant models were fabricated using the corresponding certified CAD-CAM workflow. In addition, a conventional impression was taken (CON) and a gypsum model fabricated. Three consecutive impressions were acquired with each impression system. Following fabrication, all implant models were scanned. The datasets were aligned by a repeated best-fit algorithm and the precision for the implant analog and the adjacent teeth was measured. The precision served as a measure for reproducibility. RESULTS Mean precision values of the implant analog in the digital models were 57.2 ± 32.6 µm (ITE), 88.6 ± 46.0 µm (TRI), and 176.7 ± 120.4 µm (LTD). Group CON (32.7 ± 11.6 µm) demonstrated a statistically significantly lower mean precision value for the implant position in the implant model as compared to all other groups representing a high reproducibility. The mean precision values for the reference ranged between 31.4 ± 3.5 µm (TRI) and 39.5 ± 16.5 µm (ITE). No statistical significant difference was calculated between the four treatment groups. CONCLUSIONS The conventional implant model represented the greatest reproducibility of the implant position. Digital implant models demonstrated less precision compared to the conventional workflow.

OBJECTIVES: Electrospun cotton wool-like nanocomposite (ECWN) is a novel synthetic bone substitute that incorporates amorphous calcium phosphate nanoparticles into a biodegradable synthetic copolymer poly(lactide-co-glycolide). The objectives of this study were to develop a tooth extraction socket model in sheep for bone graft research and to compare ECWN and bovine-derived xenograft (BX) in this model. MATERIAL AND METHODS: Sixteen cross-bred female sheep were used. Bilateral mandibular premolars were extracted atraumatically. Second and third premolar sockets were filled (Latin-square allocation) with BX, ECWN or left unfilled. Resorbable collagen membranes were placed over BX and selected ECWN grafted sockets. Eight sheep per time period were sacrificed after 8 and 16 weeks. Resin-embedded undemineralised sections were analysed for descriptive histology and histomorphometric analyses. RESULTS: At 8 weeks, there were with no distinct differences in healing among the different sites. At 16 weeks, osseous healing followed a fine trabecular pattern in ECWN sites. Non-grafted sites showed thick trabeculae separated by large areas of fibrovascular connective tissue. In BX grafted sites, xenograft particles were surrounded by newly formed bone or fibrovascular connective tissue. There were no statistically significant differences in bone formation across the four groups. However, ECWN sites had significantly less residual graft material than BX sites at 16 weeks (P = 0.048). CONCLUSIONS: This first description of a tooth extraction socket model in sheep supports the utility of this model for bone graft research. The results of this study suggested that the novel material ECWN did not impede bone ingrowth into sockets and showed evidence of material resorption.

Objective To evaluate the volumetric changes occurring from prosthesis insertion to the 1-year follow-up (FU) using one- and two-piece dental implants. Methods Sixty patients were randomly assigned to receive one-piece or two-piece implants. Casts were obtained at baseline (insertion of final reconstruction) and at 1 year of loading. Finally, 33 pairs of casts (BRA = 18, STM = 15) were deemed appropriate for volumetric analysis of the peri-implant tissues. If the patients had more than one implant, one was randomly selected for analysis. Casts were scanned to obtain stereolithography (STL) files. Baseline and 1-year FU digital models were superimposed with an image analysis program. Linear and volumetric measurements were performed including (i) crown height changes (CHCs), (ii) volumetric changes, and (iii) changes in tissue thickness at three levels below the mucosal margin on the buccal side of the implants (at 1,3, and 5 mm). The Mann–Whitney U-test and the paired t-test were used to analyze the data between the two groups using the patient as the unit of analysis. Results No significant baseline differences were observed between the one- and two-piece groups for the linear measurements. The mean CHCs in the two-piece group amounted to 0.02 mm (SD ± 0.32), whereas the one-piece group exhibited a change of −0.17 mm (±0.57). The mean volume changes (VCs) were −0.12 mm (±0.27) (two-piece group) and −0.03 mm (±0.29) (one-piece group). With regard to the changes in tissue thickness, the two-piece group presented a change of −0.15 mm (±0.20) at 1 mm, −0.06 mm (±0.20) at 3 mm, and −0.2 mm (±0.51) at 5 mm. The respective values for the one-piece group were −0.03 mm (±0.35), 0.01 mm (±0.28), and −0.01 mm (±0.51) at the three levels. None of the differences in linear measurements between baseline and the 1-year FU reached significance. Positive correlations were seen for tissue thickness changes at 1 and 3 mm for both groups (P

The aim of this study was to firstly evaluate the esthetics of a dielectric multilayer coating on titanium below porcine tissue (in vitro porcine model). Secondly, a polymer model was used to investigate the same samples to compare the models to each other and discuss their validity for optical assessment of esthetic coatings for implant applications.A dielectric mirror coating was deposited on titanium substrates (Ti- Bragg) and tested below porcine tissue and polymer platelets of three test thicknesses (1 mm, 2 mm and 3 mm). Titanium without coating (Ti) was used as a negative control. Furthermore, the substrates were subjected to three different surface treatments (polished, machined and sand-blasted). The color difference values ΔL, Δa, Δb and ΔE were calculated for each sample. In total, six samples were tested in both models. Statistical analysis of the data (one sample Wilcoxon test, Kruskal-Wallis with Bonferroni-Holm corrected Mann-Whitney post hoc tests for multiple testing) was conducted for each sample in both evaluation methods.In the in vitro porcine model, sand-blasted Ti-Bragg and Ti samples showed ΔE values significantly above the threshold value of 3.70, indicating a dark appearance of the 1 mm thick covering tissue. As the test thickness increased, polished and machined Ti-Bragg samples were significantly invisible (ΔE 3.70 with P 0.05). Excessive brightening effects from Ti-Bragg samples were not observed from the in vitro porcine model, but below polymer platelets the samples exhibited significantly high ΔL values, which also resulted in a significant and visible color change (ΔE 3.70 with P 0.05).Ti-Bragg was suggested to be an appropriate coating system for dental implants to improve the soft tissue esthetics. The design of this coating system can be adjusted by varying different parameters to satisfy the requirements of an esthetic coating. The polymer model is valid for test thicknesses of 2 and 3 mm, however, one might have to increase the thickness to 1.5 mm or alter the composition of the resin for 1 mm thick platelets to increase the opacity and therefore adapt to the soft tissue situation.

OBJECTIVE To review the dental literature in terms of soft tissue augmentation procedures and their influence on peri-implant health or disease in partially and fully edentulous patients. METHODS A MEDLINE search from 1966 to 2016 was performed to identify controlled clinical studies comparing soft tissue grafting versus no soft tissue grafting (maintenance) or two types of soft tissue grafting procedures at implant sites. The soft tissue grafting procedures included either an increase of keratinized tissue or an increase of the thickness of the peri-implant mucosa. Studies reporting on the peri-implant tissue health, as assessed by bleeding or gingival indices, were included in the review. The search was complemented by an additional hand search of all selected full-text articles and reviews published between 2011 and 2016. The initial search yielded a total number of 2,823 studies. Eligible studies were selected based on the inclusion criteria (finally included: four studies on gain of keratinized tissue; six studies on gain of mucosal thickness) and quality assessments conducted. Meta-analyses were applied whenever possible. RESULTS Soft tissue grafting procedures for gain of keratinized tissue resulted in a significantly greater improvement of gingival index values compared to maintenance groups (with or without keratinized tissue) [n = 2; WMD = 0.863; 95% CI (0.658; 1.067); p < .001]. For final marginal bone levels, statistically significant differences were calculated in favor of an apically positioned flap (APF) plus autogenous grafts versus all control treatments (APF alone; APF plus a collagen matrix; maintenance without intervention [with or without residual keratinized tissue]) [n = 4; WMD = -0.175 mm; 95% CI: (-0.313; -0.037); p = .013]. Soft tissue grafting procedures for gain of mucosal thickness did not result in significant improvements in bleeding indices over time, but in significantly less marginal bone loss over time [WMD = 0.110; 95% CI: 0.067; 0.154; p < .001] and a borderline significance for marginal bone levels at the study endpoints compared to sites without grafting. CONCLUSIONS Within the limitations of this review, it was concluded that soft tissue grafting procedures result in more favorable peri-implant health: (i) for gain of keratinized mucosa using autogenous grafts with a greater improvement of bleeding indices and higher marginal bone levels; (ii) for gain of mucosal thickness using autogenous grafts with significantly less marginal bone loss.

This systematic review evaluated the evidence on the effect of the interventions aimed for lateral ridge augmentation (both simultaneously with implant placement or as a staged procedure) on peri-implant health or disease.A protocol was developed to answer the following PICO question: "In patients with horizontal alveolar ridge deficiencies (population), what is the effect of lateral bone augmentation procedures (intervention and comparison) on peri-implant health (outcome)?" Included studies were randomised controlled trials or controlled clinical trials with a follow-up of at least 12 months after implant loading. Meta-analyses were performed whenever possible, including subgroup analysis based on follow-up.Twelve final publications from eight investigations were included. The results from the meta-analysis indicated that irrespective of the type of intervention, the inflammatory changes, based on bleeding on probing (%) were minimal, both at short- (n = 1; weighted mean difference [WMD] = -1.00; 95% CI [-14.04; 12.04]; p = .881) and long-term (n = 5; WMD = -5.63; 95% CI [-18.42; 7.16]; p = .881). When comparing different treatment modalities, no significant differences were observed (n = 6; WMD = -3.36; 95% CI [-12.49; 5.77]; p .471). Similarly, changes in probing pocket depth and marginal bone levels were not significantly different among groups. The incidence of peri-implantitis was evaluated in three investigations and varied from 16% to 26% after a follow-up period of 6-8 years.The results from this systematic review and meta-analysis have shown that lateral ridge augmentation procedures can maintain peri-implant health over time with low mucosal inflammatory changes and a relatively small incidence of peri-implant bone loss.

Objective The aim of this pilot study was to test whether a porcine collagenated bone substitute block (PCBB) and collagen membrane (CM) loaded with bone morphogenetic protein-2 (BMP-2) used for horizontal ridge augmentation differ from PCBB and CM without BMP-2 regarding the osseointegration of the grafting material and the maintenance of the ridge contour. Material and methods Two semi-saddle bone defects were created in each side of the mandible of six dogs. The defects were randomly allocated to receive one of the following treatments: bone augmentation using (1) PCBB, (2) PCBB loaded with BMP-2 (PCBB-BMP2), (3) PCBB + CM and (4) PCBB + CM loaded with BMP-2 (PCBB + CM-BMP2). After 12 weeks, one titanium implant was inserted into every site. After 8 weeks, one central histological section of each site was prepared. Histomorphometrical assessments were performed evaluating the augmented area (AA), the area of new bone (NB) (primary outcome), residual bone substitute (BS) and non-mineralized tissue (NMT) within AA in mm2. In addition, the most coronal and the most buccal localizations of new bone and residual bone substitute, and the most coronal bone-to-implant contact were measured in mm. Results Clinically, all PCBB were firmly integrated and permitted implant placement. All the implants osseointegrated and exhibited complete hard-tissue coverage of the buccal surface. Bone ingrowth always reached the central portions of PCBB. AA measured 10.4 ± 4.2 mm2 for PCBB, 11.8 ± 2.8 mm2 for PCBB-BMP2, 9.8 ± 2.9 mm2 for PCBB + CM and 8.5 ± 2.2 mm2 for PCBB + CM-BMP2. Only the difference between PCBB-BMP2 and PCBB + CM-BMP2 was statistically significant (P = 0.031). NB reached 2.3 ± 1.3 mm2 for PCBB, 2 ± 0.5 mm2 for PCBB-BMP2, 2.7 ± 1.2 mm2 for PCBB + CM and 1.8 ± 0.7 mm2 for PCBB + CM-BMP2. There were no statistically significant differences regarding NB, the most coronal and the most buccal localizations of new bone, residual bone substitute and bone-to-implant contact (P > 0.05). Conclusions The addition of BMP-2 to PCBB or CM used for horizontal ridge augmentation did not render a statistically significant improvement in the maintenance of the augmented ridge contour and the new bone formation. PCBB with and without CM showed pronounced bone ingrowth and capacity to maintain the augmented ridge contour. In all the regions previously augmented with PCBB, the implants successfully integrated and presented with complete hard-tissue coverage.

OBJECTIVE To evaluate in vitro the quality of dental implant biopsies collected using trephines or a sonic instrument. METHOD Sixty implants, 4 mm long and 2.4 mm in diameter, were installed in twelve fresh bovine ribs. Biopsies were collected after using three different methods for retrieval, 20 biopsies representing each group: (A) A trephine used concentrically; (B) a trephine used eccentrically; and (C) a sonic device (Sonosurgery(®) ). The time used for biopsy collection was recorded, and an evaluation of the quality of the biopsies obtained was performed. The specimens were subsequently prepared for ground sections, and tissue-to-implant contact percentages (TIC%) were evaluated in a stereomicroscope. RESULTS Time needed for biopsy collection in Groups A and B was between 2 and 3 min, while in C, it amounted to 10-11 min. The differences between Group C and the other two groups were statistically significant (P < 0.00006). Group C showed significantly greater volumes of tissue around the apex of the implants compared with the other two groups (P < 0.027). Groups A and C showed biopsies with higher quality compared with Group B (P < 0.05). Group C presented a higher TIC% compared with the other two groups (P < 0.008). CONCLUSION Compared with the use of trephines, the use of a sonic device for harvesting biopsies resulted in higher-quality biopsies and generated smaller residual defects. However, the harvesting was more time-consuming and was limited to one aspect of the implants.

OBJECTIVES: To test whether or not vascularized interpositional periosteal-connective tissue grafts are as successful as free subepithelial connective tissue grafts in augmenting volume defects in the anterior maxilla. MATERIAL AND METHODS: Twenty subjects with Seibert class 1 ridge defects in the anterior maxilla were randomly, equally assigned to augmentation by vascularized interpositional periosteal-connective tissue graft (test) or free subepithelial connective tissue graft (control). Clinical periodontal parameters at teeth adjacent to the gap were recorded, and conventional impressions were taken prior to surgery (baseline = t0 ) and 1 (t1 ), 3 (t3 ) and 6 (t6 ) months after surgery. The casts were optically scanned, digitized and analyzed for ridge contour changes in the augmented area. Data were subjected to nonparametric statistics. RESULTS: The contour changes in labial distance between baseline and follow-up for the control group were (median, range) 1 mm, 0.37-1.45 (t0 -t1 ); 1.18 mm, 0.39-1.40 (t0 -t3 ); and 0.63 mm, 0.28-1.22 (t0 -t6 ) and for test group 1.21 mm, 0.74-2.47 (t0 -t1 ); 1.26 mm, 0.50-1.71 (t0 -t3 ); and 1.18 mm, 0.16-1.75 (t0 -t6 ). Significantly less shrinkage of the graft was observed in the test group after 6 months (P = 0.03). Clinical periodontal parameters at the neighboring teeth were stable over the follow-up period and did not differ between groups. CONCLUSIONS: Augmentation of single tooth gaps with moderate ridge defects in the anterior maxilla was successfully performed using both techniques. However, after 6 months, sites treated by the pediculated graft were superior in maintaining the initially augmented volume and showed less shrinkage of the graft. This could be attributed to better perfusion of the pediculated graft.

Objective Implant surface properties have long been identified as an important factor to promote osseointegration. The importance of nanostructures and hydrophilicity has recently been discussed. The aim of this study was to investigate how nanostructures and wettability influence osseointegration and to identify whether the wettability, the nanostructure or both in combination play the key role in improved osseointegration. Materials and Methods Twenty-six adult rabbits each received two Ti grade 4 discs in each tibia. Four different types of surface modifications with different wettability and nanostructures were prepared: hydrophobic without nanostructures (SLA), with nanostructures (SLAnano); hydrophilic with two different nanostructure densities (low density: pmodSLA, high density: SLActive). All four groups were intended to have similar chemistry and microroughness. The surfaces were evaluated with contact angle measurements, X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy and interferometry. After 4 and 8 weeks healing time, pull-out tests were performed. Results SLA and SLAnano were hydrophobic, whereas SLActive and pmodSLA were super-hydrophilic. No nanostructures were present on the SLA surface, but the three other surface modifications clearly showed the presence of nanostructures, although more sparsely distributed on pmodSLA. The hydrophobic samples showed higher carbon contamination levels compared with the hydrophilic samples. After 4 weeks healing time, SLActive implants showed the highest pull-out values, with significantly higher pull-out force than SLA and SLAnano. After 8 weeks, the SLActive implants had the highest pull-out force, significantly higher than SLAnano and SLA. Conclusions The strongest bone response was achieved with a combination of wettability and the presence of nanostructures (SLActive).

OBJECTIVES The aim of the study was to test whether or not the use of a polyethylene glycol (PEG) hydrogel with or without the addition of an arginylglycylaspartic acid (RGD) sequence applied as a matrix in combination with hydroxyapatite/tricalciumphosphate (HA/TCP) results in similar peri-implant bone regeneration as traditional guided bone regeneration procedures. MATERIAL AND METHODS In 12 beagle dogs, implant placement and peri-implant bone regeneration were performed 2 months after tooth extraction in the maxilla. Two standardized box-shaped defects were bilaterally created, and dental implants were placed in the center of the defects with a dehiscence of 4 mm. Four treatment modalities were randomly applied: i)HA/TCP mixed with a synthetic PEG hydrogel, ii)HA/TCP mixed with a synthetic PEG hydrogel supplemented with an RGD sequence, iii)HA/TCP covered with a native collagen membrane (CM), iv)and no bone augmentation (empty). After a healing period of 8 or 16 weeks, micro-CT and histological analyses were performed. RESULTS Histomorphometric analysis revealed a greater relative augmented area for groups with bone augmentation (43.3%-53.9% at 8 weeks, 31.2%-42.8% at 16 weeks) compared to empty controls (22.9% at 8 weeks, 1.1% at 16 weeks). The median amount of newly formed bone was greatest in group CM at both time-points. Regarding the first bone-to-implant contact, CM was statistically significantly superior to all other groups at 8 weeks. CONCLUSIONS Bone can partially be regenerated at peri-implant buccal dehiscence defects using traditional guided bone regeneration techniques. The use of a PEG hydrogel applied as a matrix mixed with a synthetic bone substitute material might lack a sufficient stability over time for this kind of defect.

This group was assigned the task to review the current knowledge in the areas of implant connections to abutments/reconstructions, fixation methods (cement vs. screw retained) for implant-supported reconstructions, as well as the optimal number of implants for fixed dental prosthesis and implant-supported overdentures.The literature was systematically searched and critically reviewed. Four manuscripts were produced in the four subject areas based on systematically search strategy and consensus statements, clinical recommendations and implication for future research were formulated.The following four position papers were the basis for the consensus statements, the clinical recommendations and directions for future research: Internal vs. external connections for abutments/reconstructions: A systematic review. Cemented and screw-retained implant reconstructions: A systematic review of the survival and complication rates. What is the optimal number of implants for fixed reconstructions? A systematic review. What is the optimal number of implants for removable reconstructions? A systematic review on implant-supported overdentures. The remit of this working group was to update the existing knowledge in the areas of reconstructions on implants. The group acknowledged the results of previous workshops and systematic reviews were provided by the following position papers: Stefano Gracis, Konstantinos Michalakis, Paolo Vigolo, Per Vult von Steyern, Marcel Zwahlen, Irena Sailer. Internal versus external connections for abutments/reconstructions: a systematic review. Irena Sailer, S. Mühlemann, Marcel Zwahlen, Christoph Hämmerle, Daniel Schneider. Cemented and screw-retained implant reconstructions: A systematic review of the survival and complication rates. Guido Heydecke, Frank Renouard, Ailsa Nicol, Marcel Zwahlen, Tim Joda. What is the optimal number of implants for fixed reconstructions? A systematic review. Mario Roccuzzo, Francesca Bonino, Luigi Gaudioso, Henny Meijer. What is the optimal number of implants for overdentures? A systematic review.

OBJECTIVE: Moldable in situ self-stabilizing and hardening bone graft materials facilitate handling and may be suitable for membrane-free bone regeneration methods. This study aimed to compare two moldable synthetic calcium phosphate materials in a rabbit calvarial defect model. METHOD: In 12 New Zealand white rabbits, four evenly distributed 6 mm diameter defects were drilled in the calvarial bone. Three filler materials were randomly applied to 48 defects: an in situ hardening polylactide-coated s-tricalcium phosphate (TCP), an in situ hardening polylactide-coated biphasic calcium phosphate (BCP), and a granular deproteinized bovine bone matrix (DBBM, positive control). One defect remained untreated and served as a negative control. Six animals were sacrificed after 4 weeks, and the remaining animals were sacrificed after 16 weeks. Biocompatibility, bone graft substitute integration and resorption, bone formation, defect bridging, and height of reconstructed hard tissue were assessed histologically and histomorphometrically. RESULTS: All tested materials showed good biocompatibility. Semi-quantitative analysis and pair-wise comparison suggested that BCP was more efficient in centripetal bone formation when compared with TCP. After 4 weeks, significantly more bone had formed in the defects treated with either TCP or BCP materials compared with the untreated sites. BCP and DBBM did not show macroscopic signs of degradation, whereas the TCP material was partially resorbed after 16 weeks. Otherwise, no major differences were detected between the three materials. CONCLUSION: The moldable, synthetic calcium phosphates are safe and suitable bone graft substitutes with outcomes that are comparable to the control material.

OBJECTIVES: The objective of this systematic review was to assess the 5-year survival rates and incidences of complications associated with ceramic abutments and to compare them with those of metal abutments. METHODS: An electronic Medline search complemented by manual searching was conducted to identify randomized-controlled clinical trials, and prospective and retrospective studies providing information on ceramic and metal abutments with a mean follow-up time of at least 3 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data abstraction was performed independently by three reviewers. Failure rates were analyzed using standard and random-effects Poisson regression models to obtain summary estimates of 5-year survival proportions. RESULTS: Twenty-nine clinical and 22 laboratory studies were selected from an initial yield of 7136 titles and data were extracted. The estimated 5-year survival rate of ceramic abutments was 99.1% [95% confidence interval (CI): 93.8-99.9%] and 97.4% (95% CI: 96-98.3%) for metal abutments. The estimated cumulative incidence of technical complications after 5 years was 6.9% (95% CI: 3.5-13.4%) for ceramic abutments and 15.9% (95% CI: 11.6-21.5%) for metal abutments. Abutment screw loosening was the most frequent technical problem, occurring at an estimated cumulative incidence after 5 years of 5.1% (95% CI: 3.3-7.7%). All-ceramic crowns supported by ceramic abutments exhibited similar annual fracture rates as metal-ceramic crowns supported by metal abutments. The cumulative incidence of biological complications after 5 years was estimated at 5.2% (95% CI: 0.4-52%) for ceramic and 7.7% (95% CI: 4.7-12.5%) for metal abutments. Esthetic complications tended to be more frequent at metal abutments. A meta-analysis of the laboratory data was impossible due to the non-standardized test methods of the studies included. CONCLUSION: The 5-year survival rates estimated from annual failure rates appeared to be similar for ceramic and metal abutments. The information included in this review did not provide evidence for differences of the technical and biological outcomes of ceramic and metal abutments. However, the information for ceramic abutments was limited in the number of studies and abutments analyzed as well as the accrued follow-up time. Standardized methods for the analysis of abutment strength are needed.

Aim: The aim of this randomized-controlled clinical study was to examine stability changes of palatal implants with chemically modified sandblasted/acid-etched (modSLA) titanium surface compared with a standard SLA surface, during the early stages of bone healing. Materials and methods: Forty adult volunteers were recruited and randomly assigned to the test group (modSLA surface) and to the control group (SLA surface). The test and control implants had the same microscopic and macroscopic topography, but differed in surface chemistry. To document implant stability changes resonance frequency analysis (RFA) was performed at implant insertion, at 7, 14, 21, 28, 35, 42, 49, 56, 70 and 84 days thereafter. RFA values were expressed as an implant stability quotient (ISQ). Results: Immediately after implant installation, the ISQ values for both surfaces tested were not significantly different and yielded mean values of 73.8+/-5 for the control and 72.7+/-3.9 for the test surface. In the first 2 weeks after implant installation, both groups showed only small changes and thereafter a decreasing trend in the mean ISQ levels. In the test group, after 28 days a tendency towards increasing ISQ values was observed and 42 days after surgery the ISQ values corresponded to those after implant insertion. For the SLA-control group, the trend changed after 35 days and yielded ISQ values corresponding to the baseline after 63 days. After 12 weeks of observation, the test surface yielded significantly higher stability values of 77.8+/-1.9 compared with the control implants of 74.5+/-3.9, respectively. Conclusion: The results support the potential for chemical modification of the SLA surface to positively influence the biologic process of osseointegration and to decrease the healing time. To cite this article: Schatzle M, Mannchen R, Balbach U, Hammerle CHF, Toutenburg H, Jung RE. Stability change of chemically modified SLA titanium palatal implants. A randomized controlled clinical trial.

Objectives: The aim of this study was to test whether or not customized zirconia abutments exhibit the same survival rates in canine and posterior regions as titanium abutments, and to compare the esthetic result of the two abutment types. Material and methods: Twenty-two patients with 40 implants in posterior regions were included and the implant sites were randomly assigned to 20 customized zirconia and 20 customized titanium abutments. All-ceramic (AC) and metal–ceramic (MC) crowns were fabricated. In all except two cases, the crowns were cemented on the abutments using resin or glass-ionomer cements. Two zirconia reconstructions were screw retained. At baseline, 6 and 12 months, the reconstructions were examined for technical and biological problems. Probing pocket depth (PPD), plaque (Pl) and bleeding on probing (BOP) were assessed and compared with natural control teeth. Furthermore, the difference of color (ΔE) of the peri-implant mucosa and the gingiva of control teeth was evaluated by means of a spectrophotometer (Spectroshade). The data were analyzed with Student's unpaired t-test, ANOVA and regression analyses. Results: Twenty patients with 19 zirconia and 12 titanium abutments were examined at a mean follow-up of 12.6±2.7 months. The survival rate for reconstructions and abutments was 100%. No technical or biological problems were found at the test and control sites. Two chippings (16.7%) occurred at crowns supported by titanium abutments. No difference was found regarding PPD (meanPPDZrO2 3.4±0.7 mm, mPPDTi 3.3±0.6 mm), Pl (mPlZrO2 0.2±0.3, mPlTi 0.1±1.8) and BOP (mBOPZrO2 60±30%, mBOPTi 30±40%) between the two groups. Both crowns on zirconia and titanium abutments induced a similar amount of discoloration of the soft tissue compared with the gingiva at natural teeth (ΔEZrO2 8.1±3.9, ΔETi 7.8±4.3). Conclusions: At 1 year, zirconia abutments exhibited the same survival and a similar esthetic outcome as titanium abutments.

OBJECTIVES: The aim of the present study was to test whether or not immediate implantation leads to more biological complications, when performed at extraction sockets of teeth exhibiting periapical pathology compared with teeth not exhibiting periapical pathology. MATERIALS AND METHODS: In 17 consecutively admitted patients, immediate implant placement was planned in order to replace single teeth exhibiting periapical pathology (test group). These teeth demonstrated pain, periapical radiolucency, fistula, suppuration or a combination of these findings. Another 17 consecutively admitted patients in need of single tooth replacement in the absence of periapical pathology served as the control group. Implant placement and accompanying bone regeneration were performed according to standard clinical procedures. Implants were loaded after a healing period of 3 months. Clinical and radiographical parameters were assessed at the time of implant placement (baseline) and at 12 months thereafter. RESULTS: Out of the 34 patients, four test and one control patient had to be withdrawn from the study due to the inability to obtain primary implant stability. The residual 29 implants revealed a survival rate of 100% 1 year after placement. Clinical and radiographical differences between 12 months and baseline comparing test and control groups showed no statistical significances for any of the parameters assessed. Within test and control groups there was a statistically significant loss of vertical bone height at the adjacent teeth (mesial test=0.4+/-0.6 mm, control=0.4+/-0.5 mm; distal test=0.3+/-0.2 mm, control=0.7+/-0.8 mm) as well as at the implant site (mesial test=1.9+/-1.4 mm, control=1.8+/-1.1 mm; distal test=1.7+/-1.4 mm, control=1.6+/-1.1 mm) and of buccal keratinized mucosa (test=-2.2+/-1.2 mm; control=-1.3+/-1.6 mm) between baseline and 12 months. During the first 13 weeks of healing, two sites of the test and one site of the control group showed signs of infection, which required intervention. Neither the incident of early exit nor of signs of infection was statistically significantly different between the test and the control group (Mann-Whitney U test). CONCLUSION: It is concluded that for those implants where primary stability was achieved, the immediate implant placement performed at extraction sockets exhibiting periapical pathology did not lead to an increased rate of complications and rendered an equally favorable type of tissue integration of the implants in both groups. Implant placement into such sites can, therefore, be successfully performed.

Objectives The purpose of this prospective long-term study was to evaluate the incidence of the most common technical problems, namely screw loosening, screw fracture, fracturing of veneering porcelain and framework fracture in implant-supported fixed partial dentures (FPDs), and assess the survival and success rate (event-free survival) after 5 years of function. Materials and methods In 76 partially edentulous patients, a total of 205 3i-implants (machined surface) were placed and restored with 112 implant-supported FPDs (46 single crowns, 81 splinted crowns, seven FPD bridges and 23 FPDs with cantilevers). The survival rate of FPDs supported by implants was 94.5% (CI-95: 90.1-98.8) after an average observation period of 5 years. The success rate (event-free survival) of the FPDs was 80% (CI-95: 87.3-72.7). After an observation period of 5 years the cumulative incidence of screw loosening was 6.7% (CI-95: 1.8-11.5), the cumulative incidence for screw fracture was 3.9% (CI-95: 0.1-7.7). Fracture of the veneering porcelain occurred in 5.7% (CI-95: 1.2-10.2) of all FPDs. Fracturing of the suprastructure framework was rare (1%; CI-95: 0-2.9). The overall complication incidence after 5 years was highest in the group of FPDs with cantilever, which showed the lowest success rate 68.6% (CI-95: 50-87.3), followed by single crowns (77.6%; CI-95: 53.3-100) and splinted crowns (86.1%; CI-95: 59.5-100). No complication occurred in FPD bridges. Conclusion Fixed partial dentures supported by 3i-implants showed low technical complications rates, the most common being loosening of the abutment screw. Managing these complications can cause extra amount of chair-side time and patient dissatisfaction.

UNLABELLED To evaluate volumetric changes (VC) of pontic sites with or without soft tissue grafting over 5 years. MATERIAL AND METHODS Twelve patients participating in a prospective clinical trial evaluating fixed dental prostheses (FDPs) were selected on the basis of having received a subepithelial connective tissue graft for soft volume augmentation in pontic sites (augmentation group [AG]). An additional 12 patients, belonging to the same study, that had not received soft tissue grafting were used as controls (control group [CG]). Casts made from dental impressions taken at prosthesis delivery (baseline [BL]) and at 5 years (5-FU) were digitized, and linear and volumetric measurements performed to assess the soft tissue pontic height (PH), abutment height (AH), (VC) and changes in tissue thickness (TT) on the buccal side of the pontics. RESULTS There were no significant differences at BL between the two groups for linear measurements (P > 0.05). The changes in soft tissue pontic height (PHC) amounted to a loss in the height of 0.34 mm (SD = 0.5) and 0.35 mm (0.2) for AG and CG, respectively. The mean VC amounted to a loss of 5.31 mm(3) (±1.1) (AG) and 4.32 mm(3) (±1.7) (CG). None of the changes between BL and 5-FU in volumetric and linear measurements, including TT and mean mesial and distal abutment height changes (mAHC and dAHC), reached statistically significant differences between AG and CG (P > 0.05). However the changes in linear measurements from BL to 5-FU were significant in all parameters for both groups (P < 0.01). CONCLUSION At an observational period of 5 years, pontic sites with or without grafting under FDPs demonstrated similar dimensional stability. CLINICAL RELEVANCE Pontic sites with or without grafting are volumetrically stable over 5 years.

Aim To examine the literature on novel digital imaging techniques for the assessment of outcomes in oral rehabilitation with dental implants. Material and methods An electronic search of Medline and Embase databases including studies published prior to 28th December 2014 was performed and supplemented by a manual search. A synthesis of the publications was presented describing the use of computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography, optical scanning, spectrophotometry or optical coherence tomography (OCT) related to the outcome measures in implant therapy. Results and conclusions Most of the digital imaging techniques have not yet sufficiently been validated to be used for outcome measures in implant dentistry. In clinical research, cone beam CT (CBCT) is increasingly being used for 3D assessment of bone and soft tissue following augmentation procedures and implant placement. Currently, there are no effective methods for the reduction of artifacts around implants in CBCT. Optical scanning is being used for the 3D assessment of changes in the soft tissue contour. The combination of optical scan with pre-operative CBCT allows the determination of the implant position and its spatial relation to anatomical structures. Spectrophotometry is the method most commonly used to objectively assess the color match of reconstructions and peri-implant mucosa to natural dentition and gingiva. New optical imaging techniques may be considered possible approaches for monitoring peri-implant soft tissue health. MRI and ultrasonography appear promising non-ionizing radiation imaging modalities for the assessment of soft tissue and bone defect morphologies. Optical scanners and OCT may represent efficient clinical methods for accurate assessment of the misfit between the reconstructions and the implants.

Objective Orthodontic palatal implants are commonly used and do provide reliable absolute anchorage to assist orthodontic treatment. However, once treatment is completed, removal of these temporary implants is not considered easy or risk free. This short communication presents a clinical case in which a novel noninvasive procedure was applied to remove an osseointegrated palatal implant. Material and methods A customized explantation tool, tightly fixed to the implant and precisely grasping the implant's head, was used in combination with a ratchet to unscrew the implant instead of the traditional removal by trephine. Results Only a topical anesthetic was necessary before the implant–bone contact was broken by turning the ratchet counterclockwise. The implant was retrieved without any local anesthesia. The explanted palatal implant had no bone appending to it, except in its apical anti-rotational grooves, and the healing process thereafter was unproblematic. Conclusions Noninvasive palatal implant removal offers a simple and fast approach for explantation. Moreover, it might reduce the risk of adverse patient reactions, iatrogenic tooth and nerve injuries, and possible oro-antral communications.

OBJECTIVES The objective of this experiment was to test whether or not a synthetic bone substitute (SBS) was more effective than a polyethylene glycol hydrogel as a carrier material for bone morphogenetic protein-2 (BMP-2) when attempting to regenerate bone. MATERIAL AND METHODS Two identical, box-type dehiscence defects (4 × 4 mm buccolingually and apicocoronally, and 8 mm mesiodistally) were surgically prepared on buccal sides of the left and right edentulous ridge in five beagle dogs. Following implant placement, the defects either received (i) no graft, (ii) SBS+hydrogel, (iii) SBS+BMP-2 loaded hydrogel, and (iv) BMP-2-loaded SBS+hydrogel. The animals were euthanized at 8 weeks postsurgery. Radiographic and histomorphometric analyses were performed. RESULTS The hydrogel alone was not able to stabilize the grafted bone particles at 8 weeks, and SBS+hydrogel group did not significantly differ from the control group in all volumetric measurements. On the other hand, extensively regenerated new bone was connected with most of the remaining SBS particles in the BMP-2 groups. The BMP-2 groups exhibited significantly greater new bone formation (10.65 mm(3) and 1.47 mm(2) in the SBS+BMP-2-loaded hydrogel group; 14.17 mm(3) and 0.93 mm(2) in the BMP-2-loaded SBS+hydrogel) than non-BMP-2 groups (1.27 mm(3) and 0.00 mm(2) in the control group; 2.01 mm(3) and 0.19 mm(2) in the SBS+hydrogel group) in volumetric and histomorphometric analyses (P

AIM: To test whether or not bone regeneration using deproteinized bovine bone mineral (DBBM) is comparable to hydroxyapatite/silica oxide (HA/SiO) and to test the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) as an adjunct to DBBM for localized bone regeneration. MATERIALS AND METHODS: In each of the 10 rabbits, 4 titanium cylinders were placed on the external cortical plates of their calvaria. Four treatment modalities were randomly allocated: (i) empty, (ii) HA/SiO, (iii) DBBM, and (iv) DBBM plus rhBMP-2 (DBBM/BMP). The animals were sacrificed at week 8. Descriptive histology and histomorphometric assessment using a superimposed test grid of points and cycloids were performed. RESULTS: The mean number of points of the test grid coinciding with bone within the cylinder reached 124 ± 35 bone points for empty controls, 92 ± 40 bone points for DBBM, 98 ± 44 bone points for synthetic HA/SiO, and 146 ± 34 bone points DBBM/BMP. The P-value for DBBM with and without BMP reached a borderline statistical significance of 0.051. However, the area of bone regeneration within the cylinders peaked for DBBM/BMP and was statistically significantly higher compared with empty cylinders (P

Objectives The aim of this study was to compare two different surfaces of one uniform macro-implant design in order to focus exclusively on the osseointegration properties after 2, 4 and 8 weeks and to discuss the animal model chosen. Material and methods In six mature sheep, n = 36 implants with a highly crystalline and phosphate-enriched anodized titanium oxide surface (TiU) and n = 36 implants with a hydrophilic, sandblasted, large grit and acid-etched surface (SLA) were placed in the pelvic bone. TiU implants were custom-made to match the SLA implant design. The implant stability and bone-to-implant contact (BIC) were assessed by resonance frequency (ISQ), backscatter scanning electron microscopy (B-SEM), light microscopy (LM), micro-CT and intravital fluorochrome staining. Biomechanical removal torque testing was performed. Results Overall, no statistically significant differences in BIC total (trabecular + cortical) between TiU and SLA were found via LM and B-SEM. BIC values (B-SEM; LM) in both groups revealed a steady rise in trabecular bone attachment to the implant surface after 2, 4 and 8 weeks. In the 2- to 4-week time interval in the TiU group (P = 0.005) as well as in the SLA group (P = 0.01), a statistically significant increase in BIC trabecular could be observed via LM. B-SEM values confirmed the statistically significant increase for TiU (P = 0.001). In both groups, BIC trabecular values after 8 weeks were significantly higher (P ≤ 0.05) than after 2 weeks (B-SEM; LM). Biomechanical data confirmed the histological data. Conclusion The two surfaces proved comparable osseointegration in this sheep model.