Group 5 ITI Consensus Report: Implant placement and loading protocols.

OBJECTIVES: Working Group 5 was convened to discuss and find consensus on the topics of implant placement and loading protocols associated with single missing teeth in the anterior maxilla (aesthetic zone). Consensus statements, clinical recommendations, patient perspectives and future research suggestions were developed and presented to the plenary for discussion and approval. MATERIALS AND METHODS: Two systematic reviews were developed and submitted prior to the conference. The group considered in detail the systematic reviews and developed statements, clinical recommendations, patient perspectives and future research suggestions based on the findings of the reviews and experience of group members. Definitive versions were developed after presentation to and discussion by the plenary. RESULTS: Five consensus statements were developed and approved from each systematic review. Twelve clinical recommendations were developed by the group based on both reviews and experience. Three patient perspectives were developed, and five suggestions made for future research. CONCLUSIONS: Based on the findings of the systematic reviews and experience of group members, the Type 1A protocol (immediate placement and immediate loading), when utilized in the anterior maxilla under favorable conditions, is considered predictable and is associated with high survival rates. The procedure is considered clinically viable and is associated with aesthetic outcomes, although surgical, technical, and biological complications can occur.

13-year follow-up of a randomized controlled study on zirconia and titanium abutments.

OBJECTIVES: To assess survival rates and compare technical, biological, and esthetic outcomes of customized zirconia and titanium abutments at 13 years post loading. MATERIALS AND METHODS: Initially, 22 patients with 40 implants in posterior regions were included. The sites were randomly assigned to 20 customized zirconia abutments with cemented all ceramic crowns (ACC) and 20 customized titanium abutments with cemented metal ceramic crowns (MCC). At a mean follow-up of 13.4 years, patients were examined and implants/restorations assessed for survival and technical complications, as well as biological and esthetic outcomes (pocket probing depth [PPD], bleeding on probing [BOP], plaque control record [PCR], bone level [BL], papilla index [PAP], mucosal thickness, and recession (distance of the margo mucosae [MM]/margo gingivae MG)). Descriptive analyses were performed for all outcome measures. RESULTS: Fifteen patients with 21 abutments (13 zirconia, 8 titanium) were examined at 13 years. The drop-out rate was 25% (patient level). The technical survival rate of the abutments was 100%. The survival rate on the restorative level (crowns) was 100%. The assessed biological outcomes (PPD, PCR, BOP, BL) and esthetic outcomes (MG, PAP) were similar. CONCLUSIONS: Zirconia and titanium abutments supporting single implant-borne restorations rendered a high survival rate and minimal differences in terms of technical, biological, and esthetic outcomes at 13 years of follow-up.

Patient-Reported Outcomes of Maxillary Edentulous Patients Wearing Overdentures Retained by Two Implants from Insertion to 4 Years.

PURPOSE: This cohort study evaluated patient satisfaction for maxillary implant-retained overdentures (IODs) on two implants up to 4 years and assessed the treatment effect over time. MATERIALS AND METHODS: Patients encountering problems with their conventional dentures were included and received maxillary IODs on two titanium-zirconium implants and ball anchors in the canine area. Patient satisfaction was assessed using the oral health impact profile (OHIP-20E) questionnaires both for dentures and IODs. Two months after insertion of IODs (baseline), the patients chose the preferred overdenture design with full or reduced palatal coverage. OHIP-20E questionnaires were followed according to the individual choice at 1 and 4 years, and outcomes were compared with baseline. RESULTS: Sixteen out of 21 patients were evaluated at a mean follow-up of 4 years (range: 2.4 to 4.8 years). There was no significant difference in the OHIP domains for IODs at 1 year (OHIP_total_1y: 9.5, SD: 13.0) and 4 years (OHIP_total_4y: 14.2, SD: 19.1) compared with baseline (OHIP_total_BL: 12.4, SD: 14.7). Patients were most satisfied with social disability both for IODs (OHIP_BL: 6.0, SD: 7.6; OHIP_1y: 3.4, SD: 5.4; OHIP_4y: 5.7, SD: 9.5) and dentures (OHIP_CD_old: 28, SD: 29.7; OHIP_CD_new: 25.4, SD: 28.67). Patients were least satisfied with functional limitation both for IODs (OHIP_BL: 6.0, SD: 7.6; OHIP_1y: 3.4, SD: 5.4; OHIP_4y: 5.7, SD: 9.5) and dentures (OHIP_CD_old: 28, SD: 29.7; OHIP_CD_new: 25.4, SD: 28.67). CONCLUSION: Patient satisfaction with maxillary IODs on two implants did not change from baseline to 4 years and was high at 4 years of function.

Dentin hypersensitivity monitored by cold air quantitative sensory testing.

BACKGROUND: Quantification of dentin hypersensitivity (DH) is challenging and requires standardised, graded stimulation by natural-like stimuli. OBJECTIVE: The present study aimed at identifying DH subjects and longitudinally monitoring their pain thresholds by cold air quantitative sensory testing (QST). METHODS: Subject recruitment started with an online DH questionnaire. Respondents were screened by dental air stimulation. Sensitising and habituating subjects were excluded. A recently developed stimulation device was employed for cold air QST. Single tooth DH was verified by applying an equi-intense stimulus to a control tooth. Descriptive statistics were applied for subject characteristics. Mean values were calculated for the stimulation parameters temperature and air flow. Reliability of temperatures for detecting pain and for evoking moderate pain over multiple time points within a 3-week period was analysed by two-way random single- and average-measure intra-class correlation coefficients. RESULTS: A total of 353 persons completed the online DH questionnaire of which 117 were screened. Forty-four passed the screening, yet 15 were excluded for various reasons. Twenty-nine subjects were monitored by QST across 3 weeks. Results revealed a high intra-individual stability of the temperature inducing moderate to strong pain intensity (MPI) (single-measure ICC of TMPI 0.83, P < 0.001). Mean TMPI was -13.69°C, yet it highly varied among the 29 subjects (SD ± 10.04°C). CONCLUSIONS: Using a novel approach, namely dental QST based on cold air stimuli, we present evidence for temporally stable DH perceptions over a 3-week period. The method fulfils international guideline requirements and is recommendable for obtaining valid results when testing various interventions for DH management.

A systematic review of the influence of the implant-abutment connection on the clinical outcomes of ceramic and metal implant abutments supporting fixed implant reconstructions.

OBJECTIVES: The objective of this systematic review was to assess the influence of implant-abutment connection and abutment material on the outcome of implant-supported single crowns (SCs) and fixed dental prostheses (FDPs). METHODS: An electronic Medline search complemented by manual searching was conducted to identify randomized controlled clinical trials, prospective and retrospective studies with a mean follow-up time of at least 3 years. Patients had to have been examined clinically at the follow-up visit. Failure and complication rates were analyzed using robust Poisson regression, and comparisons were made with multivariable Poisson regression models. RESULTS: The search provided 1511 titles and 177 abstracts. Full-text analysis was performed for 147 articles resulting in 60 studies meeting the inclusion criteria. Meta-analysis of these studies indicated an estimated 5-year survival rate of 97.6% for SCs and 97.0% for FDPs supported by implants with internal implant-abutment connection and 95.7% for SCs and 95.8% for FDPs supported by implants with external connection. The 5-year abutment failure rate ranged from 0.7% to 2.8% for different connections with no differences between the types of connections. The total number of complications was similar between the two connections, yet, at external connections, abutment or occlusal screw loosening was more predominant. Ceramic abutments, both internally and externally connected, demonstrated a significantly higher incidence of abutment fractures compared with metal abutments. CONCLUSION: For implant-supported SCs, both metal and ceramic abutments with internal and external connections exhibited high survival rates. Moreover, implant-supported FDPs with metal abutments with internal and external connections for also showed high survival rates.

Group 2 ITI Consensus Report: Prosthodontics and implant dentistry.

OBJECTIVES: Working Group 2 was convened to address topics relevant to prosthodontics and dental implants. Systematic reviews were developed according to focused questions addressing (a) the number of implants required to support fixed full-arch restorations, (b) the influence of intentionally tilted implants compared to axial positioned implants when supporting fixed dental prostheses (FDPs), (c) implant placement and loading protocols, (d) zirconia dental implants, (e) zirconia and metal ceramic implant supported single crowns and (f) zirconia and metal ceramic implant supported FDPs. MATERIALS AND METHODS: Group 2 considered and discussed information gathered in six systematic reviews. Group participants discussed statements developed by the authors and developed consensus. The group developed and found consensus for clinical recommendations based on both the statements and the experience of the group. The consensus statements and clinical recommendations were presented to the plenary (gathering of all conference attendees) and discussed. Final versions were developed after consensus was reached. RESULTS: A total of 27 consensus statements were developed from the systematic reviews. Additionally, the group developed 24 clinical recommendations based on the combined expertise of the participants and the developed consensus statements. CONCLUSIONS: The literature supports the use of various implant numbers to support full-arch fixed prostheses. The use of intentionally tilted dental implants is indicated when appropriate conditions exist. Implant placement and loading protocols should be considered together when planning and treating patients. One-piece zirconia dental implants can be recommended when appropriate clinical conditions exist although two-piece zirconia implants should be used with caution as a result of insufficient data. Clinical performance of zirconia and metal ceramic single implant supported crowns is similar and each demonstrates significant, though different, complications. Zirconia ceramic FDPs are less reliable than metal ceramic. Implant supported monolithic zirconia prostheses may be a future option with more supporting evidence.

One-year results of maxillary overdentures supported by 2 titanium-zirconium implants - implant survival rates and radiographic outcomes.

OBJECTIVE: To assess implant survival rates and peri-implant bone loss of 2 titanium-zirconium implants supporting maxillary overdentures at 1 year of loading. MATERIAL AND METHODS: Twenty maxillary edentulous patients (5 women and 15 men) being dissatisfied with their complete dentures were included. In total, 40 diameter-reduced titanium-zirconium implants were placed in the anterior maxilla. Local guided bone regeneration (GBR) was allowed if the treatment did not compromise implant stability. Following 3 to 5 months of healing, implant-supported overdentures were inserted on two ball anchors. Implants and overdentures were assessed at 1, 2, 4, and 8 weeks after implant insertion and 2, 4, and 12 months after insertion of overdentures (baseline). Standardized radiographs were taken at implant loading and 1 year. Implant survival rates and bone loss were the primary outcomes. RESULTS: Nineteen patients (1 dropout) with 38 implants were evaluated at a mean follow-up of 1.1 years (range 1.0-1.7 years). One implant failed resulting in an implant survival rate of 97.3%. There was a significant peri-implant bone loss of the implants at 1 year of function (mean, 0.7 mm, SD = 1.1 mm; median: 0.48 mm, IQR = 0.56 mm). CONCLUSIONS: There was a high 1-year implant survival rate for edentulous patients receiving 2 maxillary implants and ball anchors as overdenture support. However, several implants exhibited an increased amount of bone loss of more than 2 mm. Overdentures supported by 2 maxillary implants should thus be used with caution as minimally invasive treatment for specific patients encountering problems with their upper dentures until more long-term data is available.

Externally Connected Zirconia Abutments with Standard Platform are Successful Long Term in Anterior Regions.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Performance of zirconia abutments for implant-supported single-tooth crowns in esthetic areas: a retrospective study up to 12-year follow-up. Passos SP, Linke B, Larjava H, French D. Clin Oral Implants Res 2016;27(1):47-54. SOURCE OF FUNDING: Information not available TYPE OF STUDY/DESIGN: Retrospective cohort study.

Eleven-Year Follow-Up of a Prospective Study of Zirconia Implant Abutments Supporting Single All-Ceramic Crowns in Anterior and Premolar Regions.

BACKGROUND: Clinical studies on zirconia abutments report very good survival rates and biological and technical results, but few have an observation period of more than 5 years. PURPOSE: The aim of this study was to assess the long-term performance of customized zirconia implant abutments supporting all-ceramic crowns. MATERIALS AND METHODS: Twenty-seven patients receiving 54 single implants were included (25 incisors, 14 canines, 15 premolars in both jaws). Yttria-stabilized zirconia abutments were screwed to the implants with a defined torque. All-ceramic crowns were adhesively cemented onto the abutments. The implants, abutments, and crowns were clinically and radiographically examined after 11 years of use. Modified United States Public Health Service (USPHS) criteria were used to assess technical outcomes: fracture of abutment/crown framework/veneering ceramic, loosening of abutment screw/crown, marginal adaptation, anatomical form, occlusal wear, and abutment fit. The biological parameters were pocket probing depth, plaque control record, bleeding on probing, papilla index, and gingival/mucosal recession at implants and neighboring natural teeth. The cumulative success rate of abutments and crowns was calculated by the Kaplan-Meier method. The results of the USPHS criteria were analyzed descriptively. RESULTS: Sixteen patients with 31 zirconia abutments were examined at 11.3 (±0.9) years after implantation. No abutment or crown was lost. The cumulative success rate was 96.3% for abutments and 90.7% for crowns. Two abutment screws loosened, and three crowns exhibited minor chipping. There were no biological complications. CONCLUSIONS: Customized zirconia single implant abutments exhibited excellent long-term outcomes in anterior and premolar regions.

Within-Subject Comparison of Maxillary Implant-Supported Overdentures with and without Palatal Coverage.

PURPOSE: The purpose of this study was to compare patient-reported outcomes for maxillary implant-supported overdentures with and without palatal coverage. MATERIALS AND METHODS: Twenty-one maxillary edentulous patients (six women, 15 men) were included. In total, 42 implants were inserted in the anterior maxilla. All patients received implant-supported overdentures on two retentive anchors with palatal coverage for 2 months. Thereafter, patient satisfaction was assessed by means of questionnaires capturing the oral health impact profile (OHIP) on functional limitation, physical pain, psychological discomfort, physical, psychological and social disability, and handicap. Additionally, cleaning ability, general satisfaction, speech, comfort, esthetics, stability, and chewing ability were rated. Subsequently, palatal coverage was reduced, and the patients wore the overdentures for another 2 months. Patient satisfaction was obtained in the same way as above, and the evaluated parameters were compared for the two overdenture designs. RESULTS: There were no significant differences between implant-supported overdentures with and without palatal coverage for any of the OHIP domains. The evaluation of additional parameters revealed significantly higher patient satisfaction for esthetics (mean difference 8.8 mm ± 24.6) and taste (mean difference 28.4 mm ± 29.9) without palatal coverage, p < .01. CONCLUSIONS: Within the limits of this study, maxillary overdentures supported by two implants were equally satisfactory with and without palatal coverage.

Systematic review of the survival rate and incidence of biologic, technical, and esthetic complications of single implant abutments supporting fixed prostheses.

PURPOSE: To assess the 5-year survival rate and number of technical, biologic, and esthetic complications involving implant abutments. MATERIALS AND METHODS: Electronic (Medline) and hand searches were performed to assess studies on metal and ceramic implant abutments. Relevant data from a previous review were included. Two reviewers independently extracted the data. Failure and complication rates were analyzed, and estimates of 5-year survival proportions were calculated from the relationship between event rate and survival function. Multivariable robust Poisson regression was used to compare abutment characteristics. RESULTS: The search yielded 1,558 titles and 274 abstracts. Twenty-four studies were selected for data analysis. The survival rate for ceramic abutments was 97.5% (95% confidence interval [CI]): 89.6% to 99.4%) and 97.6% (95% CI: 96.2% to 98.5%) for metal abutments. The overall 5-year rate for technical complications was 11.8% (95% CI: 8.5% to 16.3%), 8.9% (95% CI: 4.3% to 17.7%) for ceramic and 12.0% (95% CI: 8.5% to 16.8%) for metal abutments. Biologic complications occurred with an overall rate of 6.4% (95% CI: 3.3% to 12.0%), 10.4% (95% CI: 1.9% to 46.7%) for ceramic, and 6.1% (95% CI: 3.1% to 12.0%) for metal abutments. CONCLUSIONS: The present meta-analysis on single-implant prostheses presents high survival rates of single implants, abutments, and prostheses after 5 years of function. No differences were found for the survival and failure rates of ceramic and metal abutments. No significant differences were found for technical, biologic, and esthetic complications of internally and externally connected abutments.

Patient-reported outcomes of maxillary implant-supported overdentures compared with conventional dentures.

OBJECTIVE: The aim of the present prospective clinical study was to compare patient-reported outcomes for maxillary conventional dentures and maxillary implant-supported dentures. MATERIAL AND METHODS: Twenty-one patients (6 women and 15 men) being edentulous in the maxilla and encountering problems with their existing dentures were included. Twelve patients (4 women and 8 men) received a new set of conventional dentures, due to insufficient dentures. In nine patients (2 women and 7 men), the existing dentures were adjusted by means of relining or rebasing. All patients received implant-supported dentures on two retentive anchors. In total, 42 implants were inserted in the anterior maxilla. The participants rated their satisfaction on their existing conventional dentures, 2 months after insertion of new conventional dentures and 2 months after insertion of implant-supported dentures. Thereby, patients responded to questionnaires capturing the oral health impact profile (OHIP) using visual analog scales. Seven domains (functional limitation, physical pain, psychological discomfort, physical, psychological and social disability and handicap) were assessed. Higher scores implied poorer patient satisfaction. In addition, the questionnaire involved the evaluation of cleaning ability, general satisfaction, speech, comfort, esthetics, stability, and chewing ability. Higher scores implied higher patient satisfaction. RESULTS: Patient satisfaction significantly increased for implant-supported dentures compared with old dentures in all seven OHIP subgroups, as well as for cleaning ability, general satisfaction, ability to speak, comfort, esthetics, and stability (P < 0.05). The comparison of new conventional dentures and implant-supported dentures revealed a statistically significantly increased satisfaction for functional limitation (difference of 33.2 mm), psychological discomfort (difference of 36.7 mm), physical disability (difference of 36.3 mm), and social disability (difference of 23.5 mm), (P < 0.05). Additionally, general satisfaction, chewing ability, speech, and stability significantly improved in implant-supported dentures (P < 0.05). CONCLUSIONS: Within the limits of this study, maxillary dentures retained by two implants provided some significant short-term improvements over conventional dentures in oral- and health-related quality of life.

Marginal bone levels and soft tissue conditions around single-tooth implants with a scalloped neck design: results of a prospective 3-year study.

PURPOSE: Scalloped implants were developed to better maintain marginal bone. Therefore, this study evaluated marginal bone levels (MBLs) and soft tissue around single implants with scalloped necks in the esthetic zone prospectively over a 3-year period. MBLs were compared to those of conventional flat-platform implants at 1 and 3 years. MATERIALS AND METHODS: Patients received anterior single-tooth implants and were divided into two groups; the test group included implants with a scalloped neck design and the control group included conventional rough-surface implants with external hex. MBLs were compared radiographically at 1 and 3 years after crown insertion. For the test group, soft and hard tissue assessments were made at six different time points, beginning at abutment connection. Mesial and distal interproximal papillae and probing depths were assessed clinically. Data were analyzed with the Student t test and repeated measures analysis of variance on ranks (P < .05). RESULTS: Twenty-four patients (17 men, 7 women) took part; each group included 12 implants. The test group had significantly more marginal bone resorption than the control group at each time point (P < .001). With respect to changes in MBL values over time, a significant difference was detected between groups mesially (P < .001) but not distally. Statistical analyses demonstrated obvious significant increases with time (P < .001) in bone resorption and mesial papilla index. A significant increase over time in probing depths was demonstrated distally (P = .003) but not mesially. CONCLUSIONS: The scalloped implant did not stabilize interproximal bone remodeling and caused more bone loss than conventional implants. Soft tissue levels were not maintained around the scalloped implants.

Five-year results of a randomized controlled clinical trial comparing zirconia and titanium abutments supporting single-implant crowns in canine and posterior regions.

OBJECTIVES: To test the survival rates, and the technical and biological complication rates of customized zirconia and titanium abutments 5 years after crown insertion. MATERIAL AND METHODS: Twenty-two patients with 40 single implants in maxillary and mandibular canine and posterior regions were included. The implant sites were randomly assigned to zirconia abutments supporting all-ceramic crowns or titanium abutments supporting metal-ceramic crowns. Clinical examinations were performed at baseline, and at 6, 12, 36 and 60 months of follow-up. The abutments and reconstructions were examined for technical and/or biological complications. Probing pocket depth (PPD), plaque control record (PCR) and Bleeding on Probing (BOP) were assessed at abutments (test) and analogous contralateral teeth (control). Radiographs of the implants revealed the bone level (BL) on mesial (mBL) and distal sides (dBL). Data were statistically analyzed with nonparametric mixed models provided by Brunner and Langer and STATA (P < 0.05). RESULTS: Eighteen patients with 18 zirconia and 10 titanium abutments were available at a mean follow-up of 5.6 years (range 4.5-6.3 years). No abutment fracture or loss of a reconstruction occurred. Hence, the survival rate was 100% for both. Survival of implants supporting zirconia abutments was 88.9% and 90% for implants supporting titanium abutments. Chipping of the veneering ceramic occurred at three metal-ceramic crowns supported by titanium abutments. No significant differences were found at the zirconia and titanium abutments for PPD (meanPPDZrO2 3.3 ± 0.6 mm, mPPDTi 3.6 ± 1.1 mm), PCR (mPCRZrO2 0.1 ± 0.3, mPCRTi 0.3 ± 0.2) and BOP (mBOPZrO2 0.5 ± 0.3, mBOPTi 0.6 ± 0.3). Moreover, the BL was similar at implants supporting zirconia and titanium abutments (mBLZrO2 1.8 ± 0.5, dBLZrO2 2.0 ± 0.8; mBLTi 2.0 ± 0.8, dBLTi 1.9 ± 0.8). CONCLUSIONS: There were no statistically or clinically relevant differences between the 5-year survival rates, and the technical and biological complication rates of zirconia and titanium abutments in posterior regions.

Systematic review of the survival rate and the incidence of biological, technical, and aesthetic complications of single crowns on implants reported in longitudinal studies with a mean follow-up of 5 years.

OBJECTIVE: To assess the 5-year survival of implant-supported single crowns (SCs) and to describe the incidence of biological, technical, and aesthetic complications. The focused question was: What is the survival rate of implants supporting single crowns and implant-supported crowns with a mean follow-up of 5 years and to which extent do biological, technical, and aesthetic complications occur? METHODS: A Medline search (2006-2011) was performed for clinical studies focusing on implant-supported SCs with a mean follow-up of at least 5 years. The search was complemented by an additional hand search and the inclusion of 24 studies from a previous systematic review (Jung et al. 2008a). Survival and complication rates were analyzed using random-effects Poisson's regression models to obtain summary estimates of 5- and 10-year proportions. RESULTS: Forty-six studies derived from an initial search count of 1083 titles and the complementary publications from the previous systematic review (Jung et al. 2008a) were selected and the data were extracted. Based on the meta-analysis, survival of implants supporting SCs at 5 years amounted to 97.2% (95% CI: 96.3-97.9%), and at 10 years amounted to 95.2% (95% CI: 91.8-97.2%). The survival of implant-supported SCs was 96.3% (95% CI: 94.2-97.6%) after 5 years and 89.4% (95% CI: 82.8-93.6%) after 10 years. For biological complications, a 5-year cumulative soft tissue complication rate of 7.1% (95% CI: 4.4-11.3%) and a cumulative complication rate for implants with bone loss >2 mm of 5.2% (95% CI: 3.1-8.6%) were calculated. Technical complications reached a cumulative incidence of 8.8% (95% CI: 5.1-15.0%) for screw-loosening, 4.1% (95% CI: 2.2-7.5%) for loss of retention, and 3.5% (95% CI: 2.4-5.2%) for fracture of the veneering material after 5 years. The cumulative 5-year aesthetic complication rate amounted to 7.1% (95% CI: 3.6-13.6%). CONCLUSIONS: The outcomes of the meta-analysis demonstrated high implant survival rates for both the single tooth implants and the respective single crowns after 5 and 10 years. However, technical, biological, and aesthetic complications were frequent.

A systematic review of the survival and complication rates of implant-supported fixed dental prostheses (FDPs) after a mean observation period of at least 5 years.

OBJECTIVES: The objective of this systematic review was to assess the 5- and 10-year survival of implant-supported fixed dental prostheses (FDPs) and to describe the incidence of biological and technical complications. METHODS: An electronic Medline search complemented by manual searching was conducted to identify prospective and retrospective cohort studies and case series on FDPs with a mean follow-up time of at least 5 years. Patients had to have been examined clinically at the follow-up visit. Failure and complication rates were analyzed using standard and random-effects Poisson regression models to obtain summary estimates of 5-year and 10-year survival and complication rates. RESULTS: The updated search provided 979 titles and 257 abstracts. Full-text analysis was performed for 90 articles resulting in a total 32 studies that met the inclusion criteria. Meta-analysis of these studies indicated an estimated survival of implants supporting FDPs of 95.6% after 5 years and 93.1% after 10 years. When machined surface implants were excluded from the analysis and only rough surface implants included, the survival rate increased to 97.2% after 5 years. The survival rate of implant-supported FDPs was 95.4% after 5 years and 80.1% after 10 years of function. When the analysis was done exclusively for metal-ceramic FDPs, hence the old gold-acrylic FDPs were excluded, the survival rate increased significantly. The survival rate of metal-ceramic implant-supported FDPs was 96.4% after 5 years and 93.9% after 10 years. Only 66.4% of the patients were free of any complications after 5 years. The most frequent complications over the 5-year observation period were fractures of the veneering material (13.5%), peri-implantitis and soft tissue complications (8.5%), loss of access hole restoration (5.4%), abutment or screw loosening (5.3%), and loss of retention of cemented FDPs (4.7%). CONCLUSION: It may be concluded that implant-supported fixed dental prostheses (FDPs) are a safe and predictable treatment method with high survival rates. However, biological and technical complications were frequent (33.6%). To minimize the incidence of complications, dental professionals should make great effort in choosing reliable components and materials for implant-supported FDPs and the patients should be placed in well-structured maintenance system after treatment.

A systematic review of the performance of ceramic and metal implant abutments supporting fixed implant reconstructions.

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.

Randomized-controlled clinical trial of customized zirconia and titanium implant abutments for single-tooth implants in canine and posterior regions: 3-year results.

OBJECTIVES: The aim was to test whether or not zirconia abutments exhibit the same survival and technical/biological outcome as titanium abutments. MATERIAL AND METHODS: Twenty-two patients receiving 40 single-tooth implants in canine and posterior regions were included. The implant sites were randomly assigned to 20 zirconia and 20 titanium abutments. All-ceramic and metal-ceramic crowns were fabricated. At baseline, 6, 12 and 36 months, the reconstructions were examined for technical and biological problems. Probing pocket depth (PPD), plaque control record (PCR) and bleeding on probing (BOP) were assessed at abutments (test) and analogous contralateral teeth (control). Standardized radiographs of the implants were made and the bone level (BL) was measured referring to the implant shoulder on mesial (mBL) and distal sides (dBL). The difference of color (DeltaE) of the peri-implant mucosa and the gingiva of control teeth was assessed with a spectrophotometer. The data were statistically analyzed with Mann-Whitney Rank and Student's unpaired t-tests. RESULTS: Eighteen patients with 18 zirconia and 10 titanium abutments were examined at a mean follow-up of 36 months (range 31.5-53.3 months). No fracture of an abutment or loss of a reconstruction was found. Hence, both exhibited 100% survival. At two metal-ceramic crowns supported by titanium abutments chipping of the veneering ceramic occurred. No difference of the biological outcome of zirconia and titanium abutments was observed: PPD (meanPPD(ZrO(2)) 3.2 +/- 1 mm, mPPD(Ti) 3.4 +/- 0.5 mm), PCR (mPCR(ZrO(2)) 0.1 +/- 0.2, mPCR(Ti) 0.1 +/- 0.2) and BOP (mBOP(ZrO(2)) 0.4 +/- 0.4, mBOP(Ti) 0.2 +/- 0.3). Furthermore, the BL was similar at implants supporting zirconia and titanium abutments (mBL(ZrO(2)) 1.7 +/- 1, dBL(ZrO(2)) 1.6 +/- 1; mBL(Ti) 2 +/- 1, dBL(Ti) 2.1 +/- 1). Both, zirconia and titanium abutments induced a similar amount of discoloration of the mucosa compared with the gingiva at natural teeth (DeltaE(ZrO(2)) 9.3 +/- 3.8, DeltaE(Ti) 6.8 +/- 3.8). CONCLUSIONS: At 3 years, zirconia and titanium abutments exhibited same survival and technical, biological and esthetical outcomes.

Randomized controlled clinical trial of customized zirconia and titanium implant abutments for canine and posterior single-tooth implant reconstructions: preliminary results at 1 year of function.

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 (DeltaE) 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 (meanPPD(ZrO2) 3.4+/-0.7 mm, mPPD(Ti) 3.3+/-0.6 mm), Pl (mPl(ZrO2) 0.2+/-0.3, mPl(Ti) 0.1+/-1.8) and BOP (mBOP(ZrO2) 60+/-30%, mBOP(Ti) 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 (DeltaE(ZrO2) 8.1+/-3.9, DeltaE(Ti) 7.8+/-4.3). CONCLUSIONS: At 1 year, zirconia abutments exhibited the same survival and a similar esthetic outcome as titanium abutments.