Treatment alternatives for the rehabilitation of the posterior edentulous maxilla.

Rehabilitation of the edentulous maxilla with implant-supported fixed dental prostheses can represent a significant clinical challenge due to limited bone availability and surgical access, among other factors. This review addresses several treatment options to replace missing teeth in posterior maxillary segments, namely the placement of standard implants in conjunction with maxillary sinus floor augmentation, short implants, tilted implants, and distal cantilever extensions. Pertinent technical information and a concise summary of relevant evidence on the reported outcomes of these different therapeutic approaches are presented, along with a set of clinical guidelines to facilitate decision-making processes and optimize the outcomes of therapy.

Rehabilitation of full-arch edentulism with fixed or removable dentures retained by root-form dental implants: A systematic review of outcomes and outcome measures used in clinical research in the last 10 years.

AIM: To evaluate outcome measures, methods of assessment, and analysis in clinical studies on the rehabilitation of full-arch edentulism with implant-supported fixed or removable prostheses. MATERIALS AND METHODS: A protocol-oriented search was conducted in MEDLINE via PubMed, EMBASE, and Cochrane Library (PROSPERO registration CRD42021265179) from 1 January 2011 to 27 July 2021 to identify longitudinal studies reporting on the rehabilitation of edentulous patients with implant-supported prostheses. The primary aim of this study was the collection of all objectively reported outcomes in each study. Secondary aims included the description of the methods of assessment and analytical methods. Risk of bias was applied according to the study design (randomized controlled trial, cohort study, or descriptive pre-post study). Individual study data were extracted into an outcomes matrix. Outcomes were grouped into domains and descriptively analysed. A network diagram was generated to establish relationships between domains. The present review follows the PRISMA statement. RESULTS: The screening and selection processes resulted in the identification of 491 publications, corresponding to 421 different studies (cohorts of patients). Only 24% of the studies reported the use of EQUATOR network guidelines. Implant failure/survival was the most reported outcome (270 studies), but the criterion to determine implant failure and/or survival was frequently not described or was ambiguous. Implant success was much less frequently reported (88) and was based on several heterogenous composite definitions. Marginal bone levels (233 studies), technical complications (158), and clinical outcomes (150), including peri-implant soft tissue and implant stability assessment, were also frequently reported. Patient-reported outcome measures (PROMs) (145) and function-based outcomes (40) were predominantly reported in isolation from other outcomes and most frequently in removable restorations. While quality of life was evaluated using valid instruments, patient satisfaction was evaluated based on a common sense concept of satisfaction. Economic outcomes were under-reported (13). CONCLUSIONS: There is great heterogeneity in the criteria to define implant failure or survival and implant success, which prevents the comparison of rates across studies. Even though studies frequently report multiple outcomes, PROMs are usually reported in isolation from other outcomes. It would be valuable to have a set of core outcome variables and standardized methods of measurement for future studies.

Rehabilitation of full-arch edentulism with fixed or removable dentures retained by root-form dental implants: A systematic review of outcomes and outcome measures used in clinical research in the last 10 years.

AIM: To evaluate outcome measures, methods of assessment, and analysis in clinical studies on the rehabilitation of full-arch edentulism with implant-supported fixed or removable prostheses. MATERIALS AND METHODS: A protocol-oriented search was conducted in MEDLINE via PubMed, EMBASE, and Cochrane Library (PROSPERO registration CRD42021265179) from 1 January 2011 to 27 July 2021 to identify longitudinal studies reporting on the rehabilitation of edentulous patients with implant-supported prostheses. The primary aim of this study was the collection of all objectively reported outcomes in each study. Secondary aims included the description of the methods of assessment and analytical methods. Risk of bias was applied according to the study design (randomized controlled trial, cohort study, or descriptive pre-post study). Individual study data were extracted into an outcomes matrix. Outcomes were grouped into domains and descriptively analysed. A network diagram was generated to establish relationships between domains. The present review follows the PRISMA statement. RESULTS: The screening and selection processes resulted in the identification of 491 publications, corresponding to 421 different studies (cohorts of patients). Only 24% of the studies reported the use of EQUATOR network guidelines. Implant failure/survival was the most reported outcome (270 studies), but the criterion to determine implant failure and/or survival was frequently not described or was ambiguous. Implant success was much less frequently reported (88) and was based on several heterogenous composite definitions. Marginal bone levels (233 studies), technical complications (158), and clinical outcomes (150), including peri-implant soft tissue and implant stability assessment, were also frequently reported. Patient-reported outcome measures (PROMs) (145) and function-based outcomes (40) were predominantly reported in isolation from other outcomes and most frequently in removable restorations. While quality of life was evaluated using valid instruments, patient satisfaction was evaluated based on a common sense concept of satisfaction. Economic outcomes were under-reported (13). CONCLUSIONS: There is great heterogeneity in the criteria to define implant failure or survival and implant success, which prevents the comparison of rates across studies. Even though studies frequently report multiple outcomes, PROMs are usually reported in isolation from other outcomes. It would be valuable to have a set of core outcome variables and standardized methods of measurement for future studies.

Scientific rationale for study: Consistent data on the outcomes of treatments for full-arch edentulism are fundamental for establishing high-quality clinical practices with effective impact on patients' lives. Principal findings: Despite the increasing number of studies assessing the rehabilitation of full-arch edentulism with implant-supported prostheses, there has been little adherence to reporting guidelines (EQUATOR network), resulting in high variability regarding the type of outcomes reported. The clinical performance of these restorations has been mostly evaluated using clinician-oriented and patient-reported outcomes. Assessment methods are frequently not described and vary across studies. Practical implications: It would be valuable to have a set of core outcome variables and standardized methods of measurement for future studies.

Systematic review evaluating the influence of the prosthetic material and prosthetic design on the clinical outcomes of implant-supported multi-unit fixed dental prosthesis in the posterior area.

OBJECTIVE: The objectives of the study were to assess the survival, failure, and technical complication rates of implant-supported fixed dental prosthesis (iFDPs) with pontic or splinted crown (iSp C) designs in the posterior area and compare the influence of prosthetic materials and prosthetic design on the outcomes. METHODS: Electronic and manual searches were performed to identify randomized-, prospective-, and retrospective clinical trials with follow-up time of ≥12 months, evaluating the clinical outcomes of posterior iFDPs with pontic or iSp Cs. Survival and complication rates were analyzed using robust Poisson's regression models. RESULTS: Thirty-two studies reporting on 42 study arms were included in the present systematic review. The meta-analysis of the included studies indicated estimated 3-year survival rates of 98.3% (95%CI: 95.6-99.3%) for porcelain-fused-to-metal (PFM) iFDPs, 97.5% (95%CI: 95.5-98.7%) for veneered zirconia (Zr) iFDPs with pontic, 98.9% (95%CI: 96.8-99.6%) for monolithic or micro-veneered zirconia iFDPs with pontic, and 97.0% (95%CI: 84.8-99.9%) for lithium disilicate iFDPs with pontics. The survival rates for different material combination showed no statistically significant differences. Veneered restorations, overall, showed significantly (p < .01) higher ceramic fracture and chipping rates compared with monolithic restorations. Furthermore, there was no significant difference in survival rates (98.3% [95%CI: 95.6-99.3%] vs. 99.1% [95%CI: 97.6-99.7%]) and overall complication rates between PFM iFDPs with pontic and PFM iSp Cs. CONCLUSIONS: Based on the data identified by this systematic review, PFM, veneered Zr, and monolithic Zr iFDPs with pontic and iSp Cs showed similarly high short-term survival rates in the posterior area. Veneered restorations exhibit ceramic chipping more often than monolithic restorations, with the highest fracture rate reported for veneered Zr iFDPs.

Prosthetic failures in dental implant therapy.

Both fixed and removable implant-supported prostheses are well-established methods for replacing missing teeth in partially or fully edentulous patients. Numerous systematic reviews have been performed in recent years to evaluate the survival and complication rates of implant-retained fixed dental prostheses and implant-retained overdentures, displaying high 5-year survival rates ranging from 97.1% for fixed dental prostheses to 95%-100% for implant-retained overdentures. However, the survival rates only represent the prostheses remaining in use for a defined follow-up time, and do not account for the potential prosthetic complications that may have arisen and influence the general success of the implant treatment. The most common technical complications of fixed implant-retained single crowns are crown fracture, fractures of ceramic implant abutments, and esthetic problems. The predominant technical complication at multiple-unit, implant-retained fixed dental prostheses is fracture/chipping of the veneering ceramic. Reported technical complications for implant-retained overdentures are overdenture fracture or chipping of the veneer materials, whereas mechanical complications include implant fracture, attachment failure, and attachment housing or insert complications. To reduce the risk of such failures, a comprehensive pretreatment diagnostic work-up is essential, including defining the prosthetic goal with the aid of a wax-up or set-up and the associated ideal, prosthetically oriented three-dimensional implant position. Furthermore, selection of the ideal type of prosthesis, including the respective implant components and materials, is important for clinical long-term treatment success.

A systematic review and meta-analysis evaluating the survival, the failure, and the complication rates of veneered and monolithic all-ceramic implant-supported single crowns.

OBJECTIVE: To assess the survival, failure, and complication rates of veneered and monolithic all-ceramic implant-supported single crowns (SCs). METHODS: Literature search was conducted in Medline (PubMed), Embase, and Cochrane Central Register of Controlled Trials until September 2020 for randomized, prospective, and retrospective clinical trials with follow-up time of at least 1 year, evaluating the outcome of veneered and/or monolithic all-ceramic SCs supported by titanium dental implants. Survival and complication rates were analyzed using robust Poisson's regression models. RESULTS: Forty-nine RCTs and prospective studies reporting on 57 material cohorts were included. Meta-analysis of the included studies indicated an estimated 3-year survival rate of veneered-reinforced glass-ceramic implant-supported SCs of 97.6% (95% CI: 87.0%-99.6%). The estimated 3-year survival rates were 97.0% (95% CI: 94.0%-98.5%) for monolithic-reinforced glass-ceramic implant SCs, 96.9% (95% CI: 93.4%-98.6%) for veneered densely sintered alumina SCs, 96.3% (95% CI: 93.9%-97.7%) for veneered zirconia SCs, 96.1% (95% CI: 93.4%-97.8%) for monolithic zirconia SCs and only 36.3% (95% CI: 0.04%-87.7%) for resin-matrix-ceramic (RMC) SCs. With the exception of RMC SCs (p < 0.0001), the differences in survival rates between the materials did not reach statistical significance. Veneered SCs showed significantly (p = 0.017) higher annual ceramic chipping rates (1.65%) compared with monolithic SCs (0.39%). The location of the SCs, anterior vs. posterior, did not influence survival and chipping rates. CONCLUSIONS: With the exception of RMC SCs, veneered and monolithic implant-supported ceramic SCs showed favorable short-term survival and complication rates. Significantly higher rates for ceramic chipping, however, were reported for veneered compared with monolithic ceramic SCs.

Fabrication, workflow and delivery of reconstruction: Summary and consensus statements of group 4. The 6th EAO Consensus Conference 2021.

OBJECTIVES: To report assessments of four systematic reviews (SRs) on (i) clinical outcomes of all-ceramic implant-supported crowns (iSCs), (ii) production time, effectiveness, and costs of computer-assisted manufacturing (CAM), (iii) computer-assisted implant planning and surgery (CAIPS) time and costs, and (iv) patient-reported outcome measures (PROMS). MATERIAL AND METHODS: An author group consisting of experienced clinicians and content experts discussed and evaluated the SRs and formulated consensus on the main findings, statements, clinical recommendations, and need for future research. RESULTS: All four SRs were conducted and reported according to PRISMA and detailed comprehensive search strategies in at least three bibliometric databases and hand searching. The search strategies were deemed reproducible. Variation was noted regarding language restrictions and inclusion of grey literature, but the search comprehensiveness appeared persuasive. The SRs included bias risk assessments of the primary studies, and their study methodology impacted the interpretations of the extracted data. CONCLUSIONS: (i) There is limited evidence (49 NRCT) showing that veneered and monolithic all-ceramic iSCs have excellent outcomes observed up to 3 years. (ii) There is no evidence evaluating production time and effectiveness comparing subtractive and additive CAM of implant models, abutments and crowns. (iii) There is limited evidence (4 RCT) that CAIPS involves more time and costs when considering the entire workflow and for diagnostics, manufacturing, and insertion of the restoration. Time seems to be the decisive factor for higher costs. (iv) Patients' comfort increases when optical compared to conventional impressions are used for fabricating iSCs and short-span FPDs (2 RCT, 5 NRCT).

The effect of systemic antibiotics on clinical and patient-reported outcome measures of oral implant therapy with simultaneous guided bone regeneration.

OBJECTIVES: The aim of the present superiority study was to determine the effect of systemic antibiotics primarily on patient-reported outcome measures (PROMs) and post-surgical complications in patients undergoing oral implant therapy with simultaneous guided bone regeneration (GBR). MATERIALS AND METHODS: A total of 236 medically and periodontally healthy patients received oral implants with simultaneous GBR at seven centres. Pre-operative antibiotics of 2 g amoxicillin were prescribed to the test group 1 hr prior to surgery and 500 mg thrice daily on days 1-3 after surgery. The control group was given a placebo. Group allocation was performed randomly. Primary outcome variables were PROMs recorded as visual analogue scale scores assessed on days 1-7 and 14 on pain, swelling, haematoma and bleeding. Post-operative complications as secondary outcome variables were examined at 1, 2, 4 and 12 weeks from surgery. Chi-square tests and repeated measures of analysis of variance (ANOVA) were performed for statistical evaluation. RESULTS: No statistically significant differences (p > .05) between the two groups were detected for the evaluated PROMs. The same was noted with respect to post-surgical complications. Four implants were lost-three in the test group and one in the control group. CONCLUSION: In this trial, systemic antibiotics did not provide additional benefits to PROMs, nor the prevention of post-surgical complications in medically and periodontally healthy patients undergoing oral implant therapy with simultaneous GBR. However, further studies with larger sample sizes are still required to support the clinical outcomes of this study.

Regeneration of alveolar ridge defects. Consensus report of group 4 of the 15th European Workshop on Periodontology on Bone Regeneration.

BACKGROUND AND AIMS: Bone augmentation procedures to enable dental implant placement are frequently performed. The remit of this working group was to evaluate the current evidence on the efficacy of regenerative measures for the reconstruction of alveolar ridge defects. MATERIAL AND METHODS: The discussions were based on four systematic reviews focusing on lateral bone augmentation with implant placement at a later stage, vertical bone augmentation, reconstructive treatment of peri-implantitis associated defects, and long-term results of lateral window sinus augmentation procedures. RESULTS: A substantial body of evidence supports lateral bone augmentation prior to implant placement as a predictable procedure in order to gain sufficient ridge width for implant placement. Also, vertical ridge augmentation procedures were in many studies shown to be effective in treating deficient alveolar ridges to allow for dental implant placement. However, for both procedures the rate of associated complications was high. The adjunctive benefit of reconstructive measures for the treatment of peri-implantitis-related bone defects has only been assessed in a few RCTs. Meta-analyses demonstrated a benefit with regard to radiographic bone gain but not for clinical outcomes. Lateral window sinus floor augmentation was shown to be a reliable procedure in the long term for the partially and fully edentulous maxilla. CONCLUSIONS: The evaluated bone augmentation procedures were proven to be effective for the reconstruction of alveolar ridge defects. However, some procedures are demanding and bear a higher risk for post-operative complications.

European Association for Osseointegration Delphi study on the trends in Implant Dentistry in Europe for the year 2030.

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 (<65%); moderate consensus (65%-85%); and high consensus (≥86%). Within the topic categories, a consensus was reached (mainly moderate consensus) for the majority of questions discussed among experts during a face to face consensus meeting. However, consensus was not reached for a small number of questions/topics. CONCLUSIONS: About 82% of the questions reached consensus. The consensus points towards a lower number of implants to replace chewing units, with implants surfaces made of bioactive materials with reduced micro-roughness using mainly customized abutments with polished surfaces and an internal implant-abutment connection (85%). CBCT-3D technologies will be the main tool for pre-surgical implant placement diagnosis together with direct digital restorative workflows. There will be an increase in the incidence of peri-implantitis, although there will be more efficient interventions its treatment and prevention.

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.

A systematic review of the survival and complication rates of zirconia-ceramic and metal-ceramic multiple-unit fixed dental prostheses.

OBJECTIVES: The aim of the present review was to compare the outcomes, that is, survival and complication rates of zirconia-ceramic and/or monolithic zirconia implant-supported fixed dental prostheses (FDPs) with metal-ceramic FDPs. MATERIALS AND METHODS: An electronic MEDLINE search complemented by manual searching was conducted to identify randomized controlled clinical trials, prospective cohort studies and retrospective case series on implant-supported FDPs with a mean follow-up of at least 3 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data extraction was performed independently by two reviewers. Failure and complication rates were analyzed using robust Poisson regression models to obtain summary estimates of 5-year proportions. RESULTS: The search provided 5,263 titles and 455 abstracts. Full-text analysis was performed for 240 articles resulting in 19 studies on implant FDPs that met the inclusion criteria. The studies reported on 932 metal-ceramic and 175 zirconia-ceramic FDPs. Meta-analysis revealed an estimated 5-year survival rate of 98.7% (95% CI: 96.8%-99.5%) for metal-ceramic implant-supported FDPs, and of 93.0% (95% CI: 90.6%-94.8%) for zirconia-ceramic implant-supported FDPs (p < 0.001). Thirteen studies including 781 metal-ceramic implant-supported FDPs estimated a 5-year rate of ceramic fractures and chippings to be 11.6% compared with a significantly higher (p < 0.001) complication rate for zirconia implant-supported FDPs of 50%, reported in a small study with 13 zirconia implant-supported FDPs. Significantly (p = 0.001) more, that is, 4.1%, of the zirconia-ceramic implant-supported FDPs were lost due to ceramic fractures compared to only 0.2% of the metal-ceramic implant-supported FDPs. Detailed analysis of factors like number of units of the FDPs or location in the jaws was not possible due to heterogeneity of reporting. No studies on monolithic zirconia implant-supported FDPs fulfilled the inclusion criteria of the present review. Furthermore, no conclusive results were found for the aesthetic outcomes of both FDP-types. CONCLUSION: For implant-supported FDPs, conventionally veneered zirconia should not be considered as material selection of first priority, as pronounced risk for framework fractures and chipping of the zirconia veneering ceramic was observed. Monolithic zirconia may be an interesting alternative, but its clinical medium- to long-term outcomes have not been evaluated yet. Hence, metal ceramics seems to stay the golden standard for implant-supported multiple-unit FDPs.

A systematic review of the survival and complication rates of zirconia-ceramic and metal-ceramic single crowns.

OBJECTIVES: The aim of the present systematic review was to analyze the survival and complication rates of zirconia-based and metal-ceramic implant-supported single crowns (SCs). MATERIALS AND METHODS: An electronic MEDLINE search complemented by manual searching was conducted to identify randomized controlled clinical trials, prospective cohort and retrospective case series on implant-supported SCs with a mean follow-up time of at least 3 years. Patients had to have been clinically examined at the follow-up visit. Assessment of the identified studies and data extraction was performed independently by two reviewers. Failure and complication rates were analyzed using robust Poisson's regression models to obtain summary estimates of 5-year proportions. RESULTS: The search provided 5,263 titles and 455 abstracts, full-text analysis was performed for 240 articles, resulting in 35 included studies on implant-supported crowns. Meta-analysis revealed an estimated 5-year survival rate of 98.3% (95% CI: 96.8-99.1) for metal-ceramic implant supported SCs (n = 4,363) compared to 97.6% (95% CI: 94.3-99.0) for zirconia implant supported SCs (n = 912). About 86.7% (95% CI: 80.7-91.0) of the metal-ceramic SCs (n = 1,300) experienced no biological/technical complications over the entire observation period. The corresponding rate for zirconia SCs (n = 76) was 83.8% (95% CI: 61.6-93.8). The biologic outcomes of the two types of crowns were similar; yet, zirconia SCs exhibited less aesthetic complications than metal-ceramics. The 5-year incidence of chipping of the veneering ceramic was similar between the material groups (2.9% metal-ceramic, 2.8% zirconia-ceramic). Significantly (p = 0.001), more zirconia-ceramic implant SCs failed due to material fractures (2.1% vs. 0.2% metal-ceramic implant SCs). No studies on newer types of monolithic zirconia SCs fulfilled the simple inclusion criteria of 3 years follow-up time and clinical examination of the present systematic review. CONCLUSION: Zirconia-ceramic implant-supported SCs are a valid treatment alternative to metal-ceramic SCs, with similar incidence of biological complications and less aesthetic problems. The amount of ceramic chipping was similar between the material groups; yet, significantly more zirconia crowns failed due to material fractures.

Fracture strength of zirconia implant abutments on narrow diameter implants with internal and external implant abutment connections: A study on the titanium resin base concept.

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 < .05). Titanium abutments (C) had significantly higher bending moments than identical zirconia abutments (T1) (p < .05). Zirconia abutments (T1) with internal connection had higher bending moments than zirconia abutments with external connection (T2) (p < .05). For all test groups, the bending moments were significantly reduced when restored with all-ceramic crowns. CONCLUSIONS: For narrow diameter abutments, the fracture strength of 2-piece internal connected zirconia abutments fixed on titanium resin bases was similar to those obtained for 1-piece titanium abutments. Narrow diameter zirconia abutments with internal connection exhibited higher fracture strength than zirconia abutments with an external connection. Titanium abutments with an internal connection were significantly stronger than identical zirconia abutments.

Reconstructive aspects: Summary and consensus statements of group 3. The 5th EAO Consensus Conference 2018.

OBJECTIVES: The tasks of this working group were to evaluate the existing evidence on the efficiency and efficacy of the digital and conventional workflows for the fabrication of fixed implant reconstructions, to assess the performance of all-ceramic fixed implant reconstructions and, finally, to evaluate the outcomes of internally and externally connected implant abutments and reconstructions. METHODS: Four reviews were available analyzing the current literature on the respective topics. One review dealt with the efficiency and efficacy of digital and conventional fabrication workflows. Two reviews analyzed the outcomes of all-ceramic fixed implant reconstructions, one focusing on single-implant reconstructions and the other evaluating multiple-unit implant fixed dental prostheses (FDPs). The fourth review evaluated the clinical outcome on external, respectively, internal implant-abutment connections. These reviews were the basis for the discussions within the group and at the plenary sessions. RESULTS: The present consensus report gives the consensus statements, the clinical recommendations, and the implications for future research as discussed and approved by the plenum of the consensus conference. The four manuscripts by Mühlemann et al., Rabel et al., Pieralli et al., and Pjetursson et al. are published as part of the journal supplement of the present EAO consensus conference.

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.

Dental implants - are they better than natural teeth?

Nowadays, patients find much information on dental treatment from the Internet. There is a vast amount of information on dental implants, in contrast to the limited information available on natural teeth. This review addresses research on survival of natural teeth and dental implants, and discusses factors affecting the survival rate of implants, as well as certain dogmas in implant dentistry. To simplify treatment planning, the article presents a classification system in which teeth are classified as secure, doubtful, or irrational to treat. Secure teeth should last for a long period of time without need for complex treatment. Doubtful teeth are teeth that might need complicated treatment and additional maintenance in order to be maintained. Teeth irrational to treat are teeth that cannot be saved and for which extraction is the only treatment option. Multiple risk factors might decrease the survival probability of teeth. The survival and success rates of dental implants will never succeed the survival rates of healthy, clean teeth. Dental implants and implant-supported restorations are an excellent treatment modality, but it must always be kept in mind that it is associated with a risk of biological and technical complications. Implants are supposed to replace missing teeth - they are not supposed to replace teeth.

A multicenter randomized, controlled clinical trial comparing the use of displacement cords, an aluminum chloride paste, and a combination of paste and cords for tissue displacement.

STATEMENT OF PROBLEM: Gingival recession after soft tissue displacement for impression making in fixed prosthodontics may pose a problem for treatment success in the esthetic areas of the mouth. Knowledge about the soft tissue reaction of common gingival displacement methods is limited. PURPOSE: The purpose of this clinical randomized controlled trial (RCT) was to evaluate changes in the marginal soft tissue height with 3 different gingival tissue displacement techniques for definitive impression making of natural teeth. MATERIAL AND METHODS: A total of 67 individuals were randomized to 3 groups. In test group 1 (P; n=22), only aluminum chloride paste was used to displace the gingiva. In test group 2 (CP; n=23), a cord was inserted, and aluminum chloride paste was also used. In the control group (C; n=22), 2 cords were used to displace the gingiva (double-cord technique). Clinical measurements of the gingival position were made before treatment began and at 30 ±10 days after prosthesis delivery. Study casts were fabricated at different stages of the treatment, standardized photographs were made, and changes in the buccal gingival position were measured using graphics editing software. In addition, the participants' perception of the clinical procedure and the technicians' evaluation of the die preparation were recorded. One-way ANOVA models were applied to compare the response variables among the groups: (a) the position of the gingival margin (millimeters), (b) mean probing pocket depth (millimeters), (c) gingival thickness (millimeters), (d) amount of keratinized tissue (millimeters), and (e) mean changes in gingival margin height (millimeters). Unpaired t tests were also used to compare the mean values between groups. For comparisons between different categories, chi-square tests were performed (α=.05 for all tests). RESULTS: In the period between impression and delivery, a minor gain in gingival height of 0.058 mm (±0.13 SD) for P and 0.013 mm (±1.19 SD) for CP. However, a minor gingival recession of 0.049 mm (±0.13 SD) was reported for group C. The results for all groups showed that 21% of abutment teeth gained >0.1 mm in gingival height, 58% had stable gingival height (0 ±0.10 mm), 21% showed minor gingival recession (0.1 to 0.5 mm), and no abutment teeth showed moderate or severe gingival recession (>0.5 mm). The incidence of minor gingival recession was 8% in group P, 23% in group CP, and 32% in group C (P=.015). Fifteen participants (24%) experienced some discomfort after the procedure. The differences between the groups were not significant (P>.05). The laboratory technicians found the definitive die preparation significantly more challenging for group P (visual analog scale [VAS], 79) and CP (VAS, 82) than group C (mean VAS, 93; P=.003). CONCLUSIONS: Minor or moderate gingival recession (<1 mm) is more likely to occur when conventional cords are used during impression making. However, the laboratory technicians found the die preparation significantly less challenging when the double-cord technique was used than when impressions were made using the paste displacement technique.

Extending the service life of existing dental restorations with esthetic and functional limitations.

Adhesive cementation is a useful procedure not only for cementing restorations onto teeth but also for attaching new ceramic restorations to existing restorations to improve their esthetics and/or function. This clinical report presents a technique for modifying an existing nonsatisfactory implant-supported fixed dental prosthesis by means of adhesively cemented veneers and onlays bonded to the pre-existing metal-ceramic surface with resin cement. This modification may avoid the replacement of the fixed dental prosthesis, reducing both treatment costs and time while fulfilling the patient's demands.

A systematic review of the survival and complication rates of resin-bonded fixed dental prostheses after a mean observation period of at least 5 years.

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.