Search

It was the aim of this 24-mo randomized controlled clinical trial to investigate whether the survival of a single median implant placed in the edentulous mandible to retain a complete denture is not compromised by immediate loading. Secondary outcomes were differences in prosthetic complications between the loading principles. Each of the 158 patients who received an implant was randomly assigned to the immediate loading group ( n = 81) or the delayed loading group ( n = 77). Recall visits were performed 1 mo after implant placement (for only the delayed loading group) and 1, 4, 12, and 24 mo after implant loading. Nine implants failed in the immediate loading group, all within the first 3 mo of implant loading, and 1 implant failed in the delayed loading group prior to loading. Noninferiority of implant survival of the immediate loading group, as compared with the delayed loading group, could not be shown ( P = 0.81). Consistent with this result, a secondary analysis with Fisher exact test revealed that the observed difference in implant survival between the treatment groups was indeed statistically significant ( P = 0.019). The most frequent prosthetic complications and maintenance interventions in the mandible were retention adjustments, denture fractures, pressure sores, and matrix exchanges. There was only 1 statistically significant difference between the groups regarding the parameter "fracture of the denture base in the ball attachment area" ( P = 0.007). The results indicate that immediate loading of a single implant in the edentulous mandible reveals inferior survival than that of delayed loading and therefore should be considered only in exceptional cases (German Clinical Trials Register: DRKS00003730). [ABSTRACT FROM AUTHOR]

The aim of this prospective randomised controlled clinical trial was to evaluate the clinical outcome of shrinkage-free ZrSiO4-ceramic full-coverage crowns on premolars and molars in comparison with conventional gold crowns over a 5-year period. Two hundred and twenty-three patients were included and randomly divided into two treatment groups. One hundred and twenty-three patients were restored with 123 ZrSiO4-ceramic crowns, and 100 patients received 100 gold crowns, which served as the control. All crowns were conventionally cemented with glass-ionomer cement. After an observation period of 6, 12, 24, 36, 48 and 60 months, the survival probability ( Kaplan- Meier) for the shrinkage-free ZrSiO4-ceramic crowns was 98·3%, 92·0%, 84·7%, 79% and 73·2% and for the gold crowns, 99%, 97·9%, 95·7%, 94·6% and 92·3%, respectively. The difference between the test and control group was statistically significant ( P = 0·0027). The gold crowns showed a better marginal integrity with less marginal discoloration than the ceramic crowns. The most common failure in the ceramic crown group was fracture of the crown. The 60-month results of this prospective randomised controlled clinical trial suggest that the use of these shrinkage-free ZrSiO4-ceramic crowns in posterior tooth restorations cannot be recommended. [ABSTRACT FROM AUTHOR]

The scientific evidence concerning prosthodontic care for the shortened dental arch (SDA) is sparse. This randomized multicenter study aimed to compare two common treatment options: removable partial dental prostheses (RPDPs) for molar replacement vs. no replacement (SDA). One of the hypotheses was that the follow-up treatment differs between patients with RPDPs and patients with SDAs during the 5-year follow-up period.Two hundred and fifteen patients with complete molar loss in one jaw were included in the study. Molars were either replaced by RPDPs or not replaced according to the SDA concept.A mean number of 4.2 (RPDP) and 2.8 (SDA) treatments for biological or technical reasons occurred during the 5-year observation time per patient. Concerning the biological aspect, no significant differences between the groups could be shown, whereas treatment arising from technical reasons was significantly more frequent for the RPDP group. When the severity of treatment was analyzed, a change over time was evident. When, at baseline, only follow-up treatment with minimal effort is required, over time there is a continuous increase to moderate and extensive effort observed for both groups (Controlled-trials.com number ISRCTN97265367). [ABSTRACT FROM PUBLISHER]

Objectives: Single midline implants in the edentulous mandible can be used to support existing complete dentures to improve patients' satisfaction and masticatory efficiency. The impact on patients' dietary habits and the influence of the loading protocol of the implants was the subject of this study., Materials and Methods: In this prospective randomized clinical trial, edentulous patients with existing complete dentures in both jaws were treated with a single midline implant in the mandible. In group A, the implants were loaded immediately, in group B the loading was delayed after three months. Patients were asked to report on their nutritional intake before implant placement and 12, 24 and 60 months after loading using a standardized two-part questionnaire., Results: Nutritional intake regarding the frequency of consumption of the requested food items did not change significantly during the 60-months study period, regardless of the loading protocol. In contrast, the second part of the questionnaire revealed that after 60 months, there was a significant decrease in avoidance of food, that had a coarse and hard texture in both groups. This significant decrease was observable in the group A in the first 12 and 24 months and in the group B after 60 months., Conclusion: A change in the patients' dietary habits due to the insertion of a single midline implant in the mandible to support the existing complete denture cannot be observed, independently to the loading protocol., Clinical Relevance: Improving the chewing efficiency by single midline implants in the edentulous mandible does not lead to a change in dietary habits., (© 2024. The Author(s).)

Objectives: To assess the long-term clinical outcome of posterior inlay-retained fixed dental prostheses (IRFDPs) with a modified design made from zirconia ceramic., Methods: In 30 patients thirty 3-unit IRFDPs were placed to replace 7 premolars (4 in the maxilla, 3 in the mandible), and 23 first molars (15 in the maxilla, 8 in the mandible). Preparations were accomplished in agreement with the general principles for ceramic inlay restorations and modified with a short retainer-wing bevel preparation within the enamel at the buccal and oral sides. The frameworks were milled from 3Y-TZP ceramic, and the pontics were veneered with feldspathic ceramic. All IRFDPs were bonded with a phosphate monomer containing luting resin after air-abrasion of the intaglio surfaces. The patients were recalled 6-12 months after placement, and then annually. Kaplan-Meier analysis was used to calculate the survival and complication rates of the IRFDPs., Results: The mean observation time was 10.6 ± 1.5 years. The 10-year cumulative survival rate was 89% with 4 failures, two of them were due to deep secondary caries with loss of retention, one due to repeated debonding with enamel fractures, and one due to generalized progressive periodontitis. The most common complication was chipping of the veneering ceramic (20.1%). Eighteen IRFDPs were free of any type of complication up to 15.4 years, which corresponds to a 10-year cumulative success rate of 70.4%., Conclusion: The long-term clinical performance of modified IRFDPs made of veneered zirconia ceramics was favorable after 10 years, therefore, they represent a treatment alternative to replace posterior single missing teeth., Clinical Significance: Zirconia-based IRFDPs fabricated in the modified design may represent a substance-preserving alternative to conventional posterior FDPs to replace posterior single missing teeth, particularly in cases where implants cannot be placed, and when the adjacent teeth already have small restorations or defects., Competing Interests: Declaration of Competing Interest We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2023. Published by Elsevier Ltd.)

The single midline implant in the edentulous mandible is a treatment concept that has often been controversially discussed. Nearly 30 years ago, the first available clinical results revealed high implant survival rates and remarkable improvements in oral comfort, function, patient satisfaction and oral health-related quality of life for edentulous patients compared to the situation with no implant. However, the clinical trials were predominantly conducted with a small number of patients over a short to medium follow-up period. Today, numerous clinical investigations on the single midline implant in the edentulous mandible, which increasingly include longer-term observation periods, are available. It is the aim of this overview to present the current literature and to highlight the clinical problems. This article is a 2023 update of a review published by the authors in the German language in 2021 in the German journal Implantologie . In total, 19 prospective clinical trials with a follow-up period of 0.5-10 years were analyzed. Over this observation period, single implants with modern rough implant surfaces in the edentulous mandible reveal high implant survival rates of between 90.9 and 100% when a conventional delayed loading protocol was applied.

Objectives: To investigate the chewing efficiency and oral health-related quality of life of edentulous patients wearing complete dentures, successively supported by one, two, and three implants in the mandible., Methods: Thirteen (13) edentulous patients of at least 50 years of age received three implants in the mandible. After a conventional submerged healing period, the central implant was uncovered and connected to the denture base using a stud attachment. Two months later, chewing efficacy was evaluated, and the two lateral implants were uncovered and connected to the denture base. The central retention element was replaced by a short healing abutment with no connection to the denture base. Chewing efficiency was evaluated two months later. Afterward, the healing abutment of the central implant was replaced by a stud attachment and again connected to the denture base. Two months later, chewing efficacy was evaluated again. Oral health-related quality of life (OHRQoL) was measured at each recall visit using the summary score of the oral health impact profile. For statistical analysis of chewing efficacy, the changes from baseline (with no implants) to one, two, and three implants were used and tested by analysis of variance with repeated mesurements., Results: Chewing efficacy clearly increased after implant loading, with a significant increase when two implants were loaded (p ≤ .05), compared to the chewing efficacy with no implants. OHRQoL also significantly improved after implant loading., Conclusions: Within the limitations of the present clinical trial regarding the number of patients, chewing efficacy as well OHRQoL of edentulous patients improve after implant placement in the mandible, irrespective of the number of implants. The best chewing efficacy was achieved with two implants., (© 2022 The Authors. Clinical Oral Implants Research published by John Wiley & Sons Ltd.)

Objectives: This multicenter randomized controlled clinical trial was conducted to investigate whether the loading protocol of single dental implants placed in the midline of edentulous mandibles will influence the implant survival or prosthetic maintenance., Materials and Methods: In total, 158 patients were randomly assigned either to the immediate loading group (n = 81) or to the delayed loading group (n = 77). All implants were loaded with an overdenture retained by a ball attachment., Results: After 5 years, 102 patients attended the follow-up investigation. Immediately loaded single implants in the midline of the edentulous mandible revealed a statistically significant lower survival rate than implants loaded conventionally over an observation period of 5 years. In the immediate loading group, 9 implants failed within the first three months of implant loading. No further implant loss was recorded for this group. Two implants failed in the delayed loading group, whereas one implant had to be removed during second-stage surgery and the second five years after implant loading. Non-inferiority of the survival rate of the midline implant of the immediate loading group, compared with the delayed loading group, could not be shown (p = .79, CI immediate loading: 74.9%; 100.0%, CI delayed loading: 73.0%; 100.0%). The observed difference in implant survival between the two treatment groups over time was statistically significant., Conclusions: The results of the present study indicate that immediate loading of a single mandibular implant in the edentulous mandible should be considered only in exceptional cases., (© 2020 The Authors. Clinical Oral Implants Research published by John Wiley & Sons Ltd.)

Objectives: The aim of the present laboratory study was to investigate the retentive properties and the wear of three different resin matrix attachments for implant overdentures as well as to assess the effects of implant angulation., Methods and Materials: Three attachment systems with either polyetheretherketone inserts (PEEK; Novaloc, Straumann, Basel, Switzerland), polyetherketoneketone inserts (PEKK; CM Loc, Cendres + Métaux, Biel, Switzerland) or nylon inserts (Locator R-Tx, Zest Dental Solutions, Escondido, California, USA) were evaluated. The patrices were connected to their implant analogues and fixed in a resin cast at implant angulations of 0° and 15°. The corresponding matrices with inserts were fixed in a stylized unilaterally removable dental prothesis. To simulate masticatory forces 30,000 insertion and removal cycles with an eccentric load of 100 N at a distance of 12 mm were performed in a chewing simulator. The retention forces were measured. The wear patterns were examined using a scanning electron microscope (SEM). The statistical analysis was performed using a one-way ANOVA followed by a Games-Howell test and a Friedman test., Results: All attachment systems revealed a significant decrease in retention after testing, except PEEK 0°/0° and PEEK 15°/15°. PEEK and PEKK attachment systems showed significantly higher retentive forces than the nylon attachment system between 5000 and 30,000 cycles. The implant angulation did not significantly influence the retention behavior for any of the three attachment systems. Patrices showed no signs of wear, whereas the matrix inserts displayed signs of deformation., Conclusion: Within the limitations of the present study, attachments with PEEK and PEKK inserts combined with titanium patrices are favorable for long-term use, both for orthogonal and tilted implants. All three attachment systems showed a high variability of the retentive forces at baseline and for subsequent cycles. This should be taken into consideration for clinical use., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The aim of this anatomical study was to investigate the genial spinal canal histologically and to reconstruct it three-dimensionally to improve understanding of its anatomy and to reveal any differences between dentate and edentulous specimens. Two tissue blocks from the mandible between the left and right second incisors, one dentate and one edentulous, were fixed in 4.5% formaldehyde, decalcified and embedded in paraffin. Serial histological sections were prepared, stained with Azan and examined microscopically. Additionally, three-dimensional models of the blocks were reconstructed using microphotographs of the sections. The genial spinal canal in the dentate specimen contained a neurovascular bundle, which branched into a nerve innervating the incisor and a neurovascular bundle, whereas that in the edentulous specimen contained some nerves for vestibular gingival innervation and a vascular bundle. The results suggest differences in the genial spinal canal between dentate and edentulous mandibles. Further research is needed to confirm this finding. Clin. Anat., 33:1102-1108, 2020. © 2019 Wiley Periodicals, Inc., (© 2019 The Authors. Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.)

Objectives: To evaluate the long-term clinical outcome of posterior metal-ceramic crowns fabricated with CAD/CAM-based laser-sintering technology (BEGO Medical, Bremen, Germany)., Materials and Methods: Sixty posterior crowns were placed in 39 patients. After tooth preparation, impression taking and model casting, the stone dies were scanned to create STL data, followed by manufacturing of crown frameworks with laser-sintering technology. A base metal alloy (CoCr) and a precious alloy (AuPt) were used for 31 and 29 posterior crowns, respectively, which were veneered using the layering technique. All crowns were cemented using glass-ionomer cement., Results: The mean observation period was 10.5 ± 3.9 years. Six patients with 10 crowns were regarded as dropout. Nine crowns had been removed, three of them were intact but they were removed due to a new prosthetic treatment plan. The cumulative survival rate of all crowns was 81% after 14.7 years. When comparing the survival rates related to the alloy used, the Gehan-Wilcoxon test showed no significant differences between both alloys. Biological complications were most commonly reported, while technical complications did not affect the function of the crowns., Conclusion: The long-term clinical outcome of posterior metal-ceramic crowns fabricated with CAD/CAM-based laser-sintering technology is very promising, so that this novel technique could be an alternative to the traditional lost wax casting process., (Copyright © 2019. Published by Elsevier Ltd.)

Objectives: The knowledge about the influence of dental treatment on health-related quality of life (HRQoL) is still limited. The aim of this multicenter randomized controlled clinical trial was to assess the effect of stabilizing an existing complete denture, by means of a single mandibular implant, on HRQoL. Furthermore, the impact of the loading protocol, i.e., immediate or delayed loading, in edentulous patients was evaluated., Methods: One hundred fifty-eight participants aged 60-89 years were randomly assigned to study group A (immediate loading; n = 81) and to group B (delayed loading; n = 78). All participants received a single midline implant in the mandible. The implants were either immediately loaded (group A) or after a closed healing period of 3 months (group B) by connecting the existing mandibular complete dentures to ball attachments. HRQoL was assessed with the Short Form-36 questionnaire of health (SF-36) at baseline, 4 months, and 24 months after implant loading., Results: Improvement of HRQoL by means of a single implant-retained mandibular overdenture could not be demonstrated after 4 and 24 months of implant loading. Furthermore, the application of two different loading protocols did not influence HRQoL ratings of study participants., Conclusion: The loading protocol is not a factor, influencing HRQoL in patients treated by a single midline implant in the edentulous mandible., Clinical Relevance: A single midline implant in the edentulous mandible, stabilizing a mandibular complete denture, cannot be recommended for improving HRQoL.

Fixed dental prostheses are the standard treatment option for replacing missing teeth when adjacent teeth require crowns or are already restored with crowns. Divergent abutment teeth axes may require invasive teeth preparation to achieve a common path of insertion, which substantially weakens residual tooth structure and increases the risk of pulpal problems. In selected cases with divergent abutment teeth in the buccal-lingual direction, the use of a rotational path of insertion might overcome these problems. This concept is presented via a clinical case history report.

Objectives: It was the aim of this clinical study to evaluate the long-term outcome of 3- to 4-unit posterior all-ceramic fixed dental prostheses (FDPs) made from veneered zirconia ceramic., Methods: Between June 2003 and February 2005, 48 patients received 58 restorations. Twenty-four FDPs had a fixed-to-fixed design (FF) and thirty-four FDPs had a cantilever design (CA). Frameworks were scanned and milled out of 3 mol% yttrium-oxide partially-stabilized zirconia ceramic (CerconBase30, Degudent) and were veneered with feldspathic ceramic (CerconCeramS, Degudent). All FDPs were cemented with glass-ionomer cement (Ketac-Cem, 3 MEspe) after air-abrading the inner crown surfaces., Results: The mean observation period was 85.4 ± 54 (FF) and 91.7 ± 50 (CA) months, respectively. Ten cantilever FDPs and 5 fixed FDPs were lost due to biological problems of the abutment teeth. Two cantilever FDPs and 4 fixed-to-fixed FDPs were lost due to technical failures of the ceramic materials. The cumulative 13-year survival rate was 43.2% (FF) (CI: 22.8-66.2%) and 52.5% (CA) (CI: 32.5-71.8), respectively. In 13 cases, intraoral repair or polishing of the fractured feldspathic ceramic veneers was needed (7 in group FF, 6 in CA). Eight abutments of six restorations (4 in FF, 4 in CA) had to be treated endodontically and caries therapy was needed in 6 abutment teeth (4 in group FF, 2 in CA). The cumulative 13-year success rate was 29.5% (FF) (CI: 12.1-55.9%) and 22.5% (CA) (CI: 7.9-49.3%)., Conclusions: Within the limitations of the present investigation, posterior fixed dental prostheses made from veneered zirconia with either a fixed-to fixed or a cantilever design show comparable survival and success rates after 13 years of clinical observation., Clinical Significance: FDPs made from veneered zirconia ceramic present high failure and complication rates, irrespective of the design (fixed-to-fixed or cantilevered)., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objectives: The aim of this prospective pilot study was to evaluate the concept of one single implant placed in the edentulous mandible to retain a complete denture with regard to implant survival and prosthodontic maintenance over an observation period of 10 years., Materials and Methods: Eleven edentulous patients were included and received one implant in the midline of the mandible. Five implants healed submerge and were uncovered 2 months later. The other six healed un-submerged and were provided with a healing abutment 4 mm in height thus moderately loaded. All denture bases were temporarily relined during the healing period and two months later provided with a ball attachment for implant retention. Implant related parameters and prosthodontic maintenance interventions were assessed four weeks after implant loading and then annually., Results: Over a mean observation period of 108.9 months (35-136 months), no implant was lost. The most frequent prosthetic maintenance intervention was activation of the matrix due to loss of retention, followed by exchange of the female part. Fracture of the denture base in the attachment area was a frequent complication and occurred in 8 cases. Two denture bases fractured twice., Conclusion: Within the limitations of this prospective pilot study, the concept of a single midline implant to retain a mandibular complete denture is promising over ten years for edentulous patients. Regular recall visits should be scheduled due to frequent maintenance interventions. Further research on this topic with a larger study cohort is needed., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Purpose: A single implant can be placed to retain an overdenture in the edentulous mandible. This study aimed at the development of Oral Health-related Quality of Life comparing immediate and delayed implant loading, i.e., loading after 3 months of submerged healing., Methods: In a randomized controlled trial, 158 participants received a single mandibular implant in the midline. Quality of life was measured using the summary score of the German 49-item Oral Health Impact Profile at baseline, one month after implant placement (direct loading group) as well as one and four months after loading., Results: Mean scores at baseline were comparable. Four months after implantation, a decrease of mean scores was recognized for both groups, indicating a significantly enhanced quality of life after treatment. When comparing the groups after both 1 and 4 months of loading, quality of life was insignificantly higher in the delayed loading group (1 month: 42.1 vs. 32.3; 4 months: 33.6 vs. 27.7). For immediate loading, an insignificant tendency to an earlier improvement was recognized (Δ 1month-baseline : 9.7, compared to Δ 1month-baseline : 6.4)., Conclusions: The single mandibular implant concept was associated with a positive impact on quality of life. However, no statistically significant influence of implant loading on quality of life was found., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: This clinical study evaluated the long-term outcome and survival rate of all-ceramic cantilever resin-bonded fixed dental prostheses (RBFDPs) made of zirconia-ceramic with a single-retainer design to replace missing incisors. In addition, whether the reason for missing incisors has an influence on the longevity of RBFDPs was analyzed., Materials and Methods: One hundred and eight zirconia ceramic cantilever RBFDPs were provided for 87 patients. Seventy-five RBFDPs replaced maxillary incisors and 33 mandibular incisors. The restorations were subsequently categorized into 3 groups according to the reasons for missing teeth (congenitally missing, trauma and other reasons). The patients were followed up annually, and the restorations were assessed for function and aesthetics. The mean observation time of the RBFDPs was 92.2±33months., Results: Six debondings and 1 loss of restoration were recorded. The lost restoration was removed at the patient's request after a small chip occurred on the mesial edge of the pontic. Three of the 6 observed debondings were caused by traumatic incidents. All debonded RBFDPs were rebonded successfully with no further complications. Zirconia ceramic RBFDPs yielded a 10-year survival rate of 98.2% and a success rate of 92.0%., Conclusions: Anterior zirconia ceramic cantilever RBFDPs provided excellent clinical longevity. The reasons for missing incisors did not influence the longevity of the cantilever RBFDPs., (Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objectives: This multi-centre randomized controlled trial was conducted to investigate, whether the masticatory performance of elderly edentulous patients is improved by placement of a single implant in the midline of the edentulous mandible, and whether improvements differ with respect to the loading protocol, i.e., implant is loaded either directly or three months later after second stage surgery., Methods: Edentulous seniors aged 60-89 years were screened according to inclusion and exclusion criteria and 163 underwent implant placement. Of those, 158 were randomly assigned either to the direct loading group A (n=81) or the conventional loading group B (n=77). Chewing efficacy was obtained before treatment, one month after implant placement during the submerged healing phase (only group B) and 1 and 4 months after implant loading., Results: The masticatory performance increased over time in both groups. Four months after loading, a significant increase was observed for both groups compared to the baseline data without implant (p≤0.05). However, between the two groups, chewing efficiency did not differ significantly at any point in time (p>0.05)., Conclusions: A single midline implant in the edentulous mandible increases masticatory performance significantly, independently from the loading protocol., Clinical Significance: A single midline implant in the edentulous mandible increases masticatory performance. The loading protocol has no influence., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Purpose: The aim of this multicenter single mandibular implant study was to compare the clinical outcome of an immediately loaded implant placed in the midline of an edentulous mandible with the clinical outcome when closed healing and delayed loading is chosen. Here, the patient recruitment period and the main reasons for exclusion were analyzed., Materials and Methods: Patient recruitment was performed at nine German universities. Rather conservative inclusion and exclusion criteria, including denture satisfaction, denture status, a psychologic symptom checklist, and a defined bone height in the posterior mandible, had to be fulfilled. It was initially calculated that 230 persons would have to be screened within 13 months to include 180 persons in the trial., Results: Within 13 months (December 2012 to December 2013), 201 patients were screened for possible inclusion in the trial and 148 met the inclusion criteria. Finally, after the recruitment period was extended by 2.5 months, 224 patients were screened and 169 were included. Of those screened, 55 (24.6%) did not meet the inclusion criteria and were excluded. Another 4 patients (1.8%) were excluded based on their psychologic symptom checklist score, while 5 others (2.8%) showed signs of noncompliance. A further 8 patients (4.4%) decided not to participate and withdrew their informed consent, and another 3 (1.3%) were no longer available after screening. Another 2 patients were excluded due to medical contraindications and 1 due to an insufficient mandibular denture. In 34 cases (15.2%), the residual bone height did not comply with McGarry type II or III., Conclusion: Within the limitations of this patient recruitment period, it can be concluded that residual bone height is the most important factor when considering elderly edentulous patients for implant therapy. The psychologic symptom checklist score was less important.

The purpose of this laboratory study was to evaluate the tensile bond strength of a new generation of universal bonding systems to zirconia ceramic and to compare the results with the bond strength of a clinically-established bonding system. Eighty zirconia ceramic test specimens (e.max ZirCAD) were air-abraded and bonded to Plexiglas tubes, filled with an aliphatic dimethacrylate filling material (Clearfil F II), using three so called universal bonding systems of a new generation with different compositions (Monobond Plus/MultilinkAutomix, NX3, Scotchbond Universal/RelyX Ultimate). The latter was used also without the phosphate monomer containing primer Scotchbond Universal. A clinically established phosphate monomer containing adhesive cement served as control group (Panavia F2.0). The specimens were stored in water at 37°C for 3 or 150 days and the long-term storage series were additionally thermal cycled between 5 and 55°C for 37,500 times to simulate oral conditions. All specimens underwent tensile bond strength testing. The statistical analysis was performed using Kruskal-Wallis and Wilcoxon-Test with a Bonferroni-Holm correction for multiple testing. After 150 days the median bond strength of RelyX Ultimate, with and without Scotchbond Universal, and Panavia F2.0 did not differ statistically (range: 21.7-28.8MPa), while the bond strength of Monobond Plus/Multilink Automix was significantly lower (15.4MPa), and that of NX3 the lowest (6.6MPa). After 150 days of water storage with thermal cycling, all adhesive system showed significantly reduced tensile bond strengths compared to that after 3 days. Only RelyX Ultimate was comparable to the established bonding system Panavia F2.0. The additional use of Scotchbond Universal did not result in a significant effect., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objectives: The purpose of this laboratory study was to evaluate the long-term retention behaviour of two resin matrix attachment systems for overdentures and the influence of the implant angulation., Methods: Sixteen titanium patrices of each attachment system were connected to their corresponding implant analogues and fixed in an auto curing resin either orthogonally (n=8) or 20° tilted (n=8). The corresponding matrices, one made from polyetherketoneketone (PEKK; CM LOC, Cendres+Métaux, Biel, Switzerland), one made from polyethylene (PE; Locator, Zest Anchors, Escondido, California, USA), were fixed in a stylised unilaterally removable dental prosthesis resulting in 4 groups with 8 specimens in each group. Overall, 30,000 joining and separating cycles of the matrix were performed in a chewing simulator. After each joining movement, the unilaterally removable dental prosthesis was loaded eccentrically with 100N at a distance of 12mm from the attachment to simulate clinical loading conditions. Retentive forces were measured during the test using force transducers. The statistical analysis was performed using Tukey-HSD., Results: Both attachment systems showed a significant decrease in retention over time, which occurred earlier in the tilted groups than in the orthogonal groups. After 5000-30,000 joining and separating cycles the PE matrix attachment provided significantly lower retention than the PEKK matrix attachment system., Conclusion: Within the limitations of this investigation, the combination of a titanium patrix and a matrix made from polyetherketoneketone seems to be a promising material combination for long-term retention, also on tilted implants., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Today, many adhesive systems with different coupling agents for tooth structures and restorative materials are available. The purpose of this in vitro study was to evaluate the tensile bond strength (TBS) of different universal adhesive systems to etched lithium disilicate ceramic., Methods: The authors etched and bonded 96 disk-like lithium disilicate ceramic specimens (IPS e.max CAD, Ivoclar Vivadent) with 4 different adhesive bonding systems to Plexiglas tubes filled with a composite resin. The authors stored the specimens in water at 37°C for 3 days without thermal cycling or for 30 or 150 days with 7,500 or 37,500 thermal cycles between 5°C and 55°C, respectively. Then, all specimens underwent TBS testing. The authors performed statistical analysis by using Kruskal-Wallis and Wilcoxon tests with a Bonferroni-Holm correction for multiple testing., Results: Initially, all adhesive systems exhibited considerable TBS, but some showed a significant reduction after 30 days of storage. After 3, 30, and 150 days, the Monobond Plus and Multilink Automix (Ivoclar Vivadent) silane-containing adhesive system showed significantly higher bond strengths to lithium disilicate ceramic than did the other universal adhesive systems, some of which do not contain silanes., Conclusions: The bond strength to lithium disilicate ceramic is affected significantly by the adhesive bonding system used., Practical Implications: Universal adhesive systems that do not contain a silane should be avoided for bonding lithium disilicate ceramic restorations because of their inferior bond strength., (Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of this prospective pilot study was to evaluate the prosthodontic maintenance as well as the implant outcome of single implant-retained mandibular overdentures over an observation period of 6 years., Methods: Eleven edentulous patients received one single implant in the midline of the mandible. Denture bases were temporarily relined and 2 months later provided with a ball attachment for implant retention. Implant related parameters and prosthodontic maintenance interventions were assessed 4 weeks after implant loading and then once a year., Results: Over a mean observation period of 75.9 months, no implant was lost. The most frequent prosthetic maintenance intervention was activation of the matrix due to loss of retention, followed by exchange of the female part. Eight denture bases had to be repaired after a fracture in the midline area., Conclusions: Within the limitations of this preliminary clinical study, the concept of a single midline implant to retain a mandibular complete denture was a successful treatment option for elderly edentulous patients., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Inlay-retained fixed dental prostheses (IRFDPs) represent a minimally invasive alternative to conventional fixed dental prostheses (FDPs) to replace single posterior missing teeth. The aim of the present review article is to assess the clinical outcome of different IRFDPs in order to derive recommendations regarding their clinical application. Hence, it is essential to highlight important factors that influence the longevity and success of IRFDPs, such as treatment plan, appropriate case selection with proper indications, as well as tooth preparation. Furthermore, a good understanding of bonding technologies and awareness of pretreatment procedures for different materials are indispensable for the long-term success of IRFDPs.

This survey of German dental schools sought to gain insight into the present prosthetic treatment concepts and their application in student and postgraduate education, as well as to compare the results to those from an identical 2002 survey. A questionnaire, based on this issue, was sent via email to the chairpersons of all prosthetic departments of the German dental schools, and 93.1% of the departments completed the questionnaire. Within the limitations of this survey, almost all treatment concepts for the reduced dentition are taught intensively at dental schools in Germany while some therapy forms are preferred.

Objectives: To evaluate the long-term survival and complication rates of posterior three-unit fixed dental prostheses (FDPs) fabricated from a glass-infiltrated zirconia reinforced alumina ceramic (In-Ceram Zirconia)., Methods: Fifty-eight patients received 65 FDPs. Twelve FDPs replaced the second premolar (8 in the maxilla, 4 in the mandible), and 53 replaced the first molar (19 in the maxilla, 34 in the mandible). The In-Ceram Zirconia ceramic frameworks were designed and milled using the Cerec CAD/CAM system. The minimum dimension of the proximal connectors of the frameworks was 12 mm(2) and 16 mm(2) for premolars and molars, respectively. After milling and glass infiltration, the frameworks were veneered with a feldspathic ceramic. All FDPs were cemented with glass-ionomer cement. The patients were recalled 6-12 months after placement, and then annually. Kaplan-Meier analysis was used to calculate the survival and complication rates of the FDPs., Results: The mean observation time was 9.7 years. Six patients with 6 FDPs were regarded as dropouts. Using the Kaplan-Meier method the 10-year cumulative survival rate was 93.6%. In a worst-case scenario, in which the 6 missing FDPs are considered as failed, the 10-year survival rate would be 84.6%., Conclusion: Three-unit posterior FDPs made from In-Ceram Zirconia presented a 10-year survival rate similar to that reported for conventional FDPs. However more technical and biological complications were reported., Clinical Significance: Three-unit posterior FDP made from In-Ceram Zirconia may be a viable treatment modality, taking the strict adherence to the manufacturer's recommendations into consideration., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Objectives: The concept of a single midline implant retaining a complete mandibular denture is controversially discussed among experts. Studies are rare in the literature, and commonly accepted recommendations for this treatment options are not available. This systematic literature review was performed to give an overview over the current literature on the single midline implant therapy for the edentulous mandible and to reveal whether this treatment option might be an alternative to commonly accepted treatment modalities with more implants., Methods: A review of the literature published until 24th of May 2013 was conducted to identify in vivo studies on the single midline implant concept with a mean follow-up time of at least 3 months., Results: From the electronic search, 11 studies were finally included. After an observation period of 3-60 months, the implant survival rate ranged from 62.5 to 100 %. The most frequent prosthetic maintenance intervention was "activation of the matrix" followed by "repair of fractured denture base.", Conclusions: The concept of one single midline implant to retain a mandibular complete denture can be an alternative, especially for elderly patients. Immediate loading of the implants should be avoided, and the way of integrating the matrix into the denture base should be carefully considered.

Background: Over the years, there has been a strong consensus in dentistry that at least two implants are required to retain a complete mandibular denture. It has been shown in several clinical trials that one single median implant can retain a mandibular overdenture sufficiently well for up to 5 years without implant failures, when delayed loading was used. However, other trials have reported conflicting results with in part considerable failure rates when immediate loading was applied. Therefore it is the purpose of the current randomized clinical trial to test the hypothesis that immediate loading of a single mandibular midline implant with an overdenture will result in a comparable clinical outcome as using the standard protocol of delayed loading., Methods/design: This prospective nine-center randomized controlled clinical trial is still ongoing. The final patient will complete the trial in 2016. In total, 180 edentulous patients between 60 and 89 years with sufficient complete dentures will receive one median implant in the edentulous mandible, which will retain the existing complete denture using a ball attachment. Loading of the median implant is either immediately after implant placement (experimental group) or delayed by 3 months of submerged healing at second-stage surgery (control group). Follow-up of patients will be performed for 24 months after implant loading. The primary outcome measure is non-inferiority of implant success rate of the experimental group compared to the control group. The secondary outcome measures encompass clinical, technical and subjective variables. The study was funded by the Deutsche Forschungsgemeinschaft (German research foundation, KE 477/8-1)., Discussion: This multi-center clinical trial will give information on the ability of a single median implant to retain a complete mandibular denture when immediately loaded. If viable, this treatment option will strongly improve everyday dental practice., Trial Registration: The trial has been registered at Deutsches Register Klinischer Studien (German register of clinical trials) under DRKS-ID: DRKS00003730 since 23 August 2012. (http://www.germanctr.de).

Unlabelled: The "smile line" is commonly used as a parameter to evaluate and categorize a person's smile. This systematic literature review assessed the existing evidence on the validity and universal applicability of this parameter. The latter was evaluated based on studies on smile perception by orthodontists, general clinicians, and laypeople., Methods: A review of the literature published between October 1973 and January 2010 was conducted with the electronic database Pubmed and the search terms "smile," "smile line," "smile arc," and "smile design.", Results: The search yielded 309 articles, of which nine studies were included based on the selection criteria. The selected studies typically correlate the smile line with the position of the upper lip during a smile while, on average, 75 to 100% of the maxillary anterior teeth are exposed. A virtual line that connects the incisal edges of the maxillary anterior teeth commonly follows the upper border of the lower lip. Average and parallel smile lines are most common, influenced by the age and gender of a person. Orthodontists, general clinicians, and laypeople have similar preferences and rate average smile lines as most attractive., Conclusions: The smile line is a valid tool to assess the esthetic appearance of a smile. It can be applied universally as clinicians and laypersons perceive and judge it similarly.