Monolithic and Minimally Veneered Zirconia Complications as Implant-Supported Restorative Material: A Retrospective Clinical Study up to 5 Years

Screw-retained ceramic-veneered/monolithic zirconia partial implant-supported fixed dental prostheses: A 5 to 10-year retrospective study on survival and complications

PURPOSE

To assess the clinical performance of screw-retained, ceramic-veneered, monolithic zirconia partial implant-supported fixed dental prostheses (ISFDP) over 5-10 years and to evaluate implant- and prosthesis-related factors influencing treatment failure and complications.

MATERIALS AND METHODS

Partially edentulous patients treated with screw-retained all-ceramic ISFDPs with 2-4 prosthetic units with a documented follow-up of ≥5 years after implant loading were included in this retrospective study. The outcomes analyzed included implant/prosthesis failure and biological/technical complications. Possible risk factors were identified using the mixed effects Cox regression analysis.

RESULTS

A screened sample of 171 participants with 208 prostheses (95% of the restorations were splinted crowns without a pontic) supported by 451 dental implants were enrolled in this study. The mean follow-up duration after prosthesis delivery was 82.4 ±17.2 months. By the end of the follow-up period, 431 (95.57%) of the 451 implants remained functional at the implant level. At the prosthesis level, 185 (88.94%) of the 208 partial ISFDPs remained functional. Biological complications were observed in 67 implants (14.86%), and technical complications were observed in 62 ISFDPs (29.81%). Analysis revealed only emergence profiles (over-contoured) as a significant risk factor for implant failure (P<0.001) and biological complications (P<0.001). Full-coverage ceramic-veneered zirconia prostheses had a significantly greater chance of chipping (P<0.001) compared with buccal-ceramic-veneered or monolithic zirconia prostheses.

CONCLUSIONS

Screw-retained ceramic-veneered, monolithic partial ISFDPs have a favorable long-term survival rate. Over-contoured emergence profile is a significant risk factor associated with implant failure and biological complications. Buccal-ceramic-veneered and monolithic zirconia partial ISFDPs lower the initial prevalence of chipping compared with a full-coverage veneered design.

Clinical performance of single implant prostheses restored using titanium base abutments: A systematic review and meta-analysis

PURPOSE

The aim of this review was to evaluate the survival rates of restorations utilizing titanium base abutments (TBA) for restoring single-unit implant prostheses.

MATERIALS AND METHODS

This review was conducted following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. The focus question was: In patients who require the restoration of a single dental implant utilizing a titanium base abutment, what are the determining factors and outcomes relating to implant prosthesis prognosis and survival? A comprehensive search of databases (PubMed, EMBASE, and Cochrane Library) was conducted on 16 April 2023 and updated on 5 May 2023. Randomized clinical trials (RCT), retrospective studies and prospective studies, reporting on the use of TBA for single implant prostheses, were reviewed. A Cochrane collaboration risk of bias assessment analysis was performed for randomized clinical studies, and the Newcastle-Ottawa Scale tool was applied for non-randomized studies. A meta-analysis was performed on clinical trials reporting on survival rates of both TBA and other abutments. Other clinical studies, reporting on TBA only, were included for descriptive statistics.

RESULTS

The search provided 1159 titles after duplicates were removed. Six RCTs were included to perform a meta-analysis and compare the survival of the TBA to other abutments [OR 0.74; 95% CI: 0.21-2.63, heterogeneity; I2 0%; p = .99]. Twenty-three prospective and retrospective studies fulfilled the criteria and were included in the meta-analysis after 12 months of function. A total of 857 single implant-supported prostheses fabricated with a TBA were included. TBA abutments have an estimate 98.6% survival rate after 1 year in function (95% CI: 97.9%-99.4%). The mean follow-up period was 31.2 ± 16.9 months.

CONCLUSIONS

Single implant prosthesis restored with titanium base abutments showed favourable short-term survival rates.

Evaluating the clinical behavior of veneered zirconia in comparison with monolithic zirconia complete arch implant-supported prostheses: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Because the use of zirconia in dentistry is relatively new, the number of published studies on the subject is scarce, even though material selection is an important factor in clinical performance. Therefore, a systematic assessment of the impact of the prosthetic material, framework design, veneering material, and manufacturing process is required.

PURPOSE

The purpose of this systematic review and meta-analysis was to investigate the survival and success rates of feldspathic porcelain veneered zirconia (VZir) in comparison with monolithic zirconia (MZir) complete arch implant-supported prostheses (CAISPs). A secondary objective was to assess the influence of the type of loading, the presence or absence of a cantilever, the type of zirconia used, the location, and the opposing arch on complications rates and patient satisfaction.

MATERIAL AND METHODS

An electronic search of the MEDLINE database (via PubMed), Scopus, Science Direct, Cochrane Library, and OpenGrey was carried out. The criteria described in the preferred reporting items for systematic reviews and meta-analyses statement were used. The search was restricted from January 2000 to January 2022.

RESULTS

The systematic search resulted in 20 articles that met the established criteria. In total, 751 patients (VZir=302; MZir=449) with 3038 CAISPs (VZir=368; MZir=2670) were analyzed. Higher prosthetic survival and success rates were found in MZir compared with VZir CAISPs (100% and 95.45%, respectively). The meta-analysis found significantly fewer complications related to MZir (9.4% [4.8%-14.1%]) compared with VZir (33.7% [17.5%-49.9%]).

CONCLUSIONS

Based on the findings of this systematic review, MZir CAISPs had higher survival and success rates than VZir CAISPs, with significantly fewer prosthetic complications. The influence of factors such as the type of functional loading, the presence of a cantilever, the material used in the prosthodontic workflow, the location of the CAISP, and the type of antagonist arch on the performance of Zir CAISPs remains unclear.

Prosthetic complications with monolithic or micro-veneered implant-supported zirconia single-unit, multiple-unit, and complete-arch prostheses on titanium base abutments: A single center retrospective study with mean follow-up period of 72.35 months

BACKGROUND

The influence of prosthetic design on prosthetic complications when monolithic or micro-veneered zirconia prostheses are supported with titanium base (ti-base) abutments is not well-known.

PURPOSE

The purpose of this single center, retrospective study was to assess the prevalence of prosthetic complications with monolithic or micro-veneered single-unit, multi-unit, and complete-arch zirconia prostheses supported with ti-base abutments (implant level or multi-unit abutment level).

MATERIAL AND METHODS

This study retrospectively evaluated the electronic health record (EHR) of participants who received either monolithic or micro-veneered implant-supported single-unit, multi-unit, and/or complete-arch prostheses supported by ti-base or zirconia-ti-base hybrid abutments delivered between the years 2010 and 2021. Data were analyzed by using logistic regression and Exact Mantel-Haenszel chi-square test (α = 0.05) to assess the clinical performance of prostheses and complications including crown decementation, feldspathic porcelain chipping, prosthesis fracture, zirconia-ti-base hybrid abutment decementation, abutment screw loosening, screw fracture, abutment fracture, implant loss, and prosthesis remake.

RESULTS

The study included 94 participants (50 female, 44 male) with a mean age of 59.5 years (range: 24-101 years of age). The retrospective EHR evaluation yielded 82 single-unit, 51 multi-unit, and 20 complete-arch prostheses on 325 implants. Among 153 prostheses delivered, 108 were micro-veneered (47 single-unit, 41 multi-unit, and 20 complete-arch prostheses) and 45 were monolithic. The average duration was 72.35 months (6.02 years) with a follow-up period of 5-132 months. From the time of insertion to the time of EHR review, of 153 prostheses, 78.43% did not exhibit any prosthetic complication. However, 33 prostheses (21.57%) from 29 participants (30.85%) had at least one prosthetic complication. Only four patients (4.25%) experienced two or more prosthetic complications. Prosthetic design affected the probability of having a complication (p = 0.005); complete-arch prostheses had higher probability (p ≤ 0.028). Single-unit prostheses had lower probability of complication than multi-unit prostheses (p = 0.005). The most commonly observed complication was fracture of veneering material (5.88%) followed by prosthetic screw loosening (4.57%) and decementation between the zirconia and the ti-base abutment (2.61%). Micro-veneered complete-arch prostheses had higher probability of having chipping than that of not having (p < 0.001), and other micro-veneered prosthetic designs had similar probability of chipping with that of complete-arch prostheses (p ≥ 0.082). Frequency of chipping was affected by veneering (p < 0.001). Monolithic prostheses had lower probability of chipping than micro-veneered prostheses, regardless of the prosthetic design (p < 0.001).

CONCLUSIONS

The frequency of prosthetic complications varied depending on prosthetic design. Complete-arch prostheses had the highest probability of complications while the single-unit prostheses had the lowest. Micro-veneered prostheses had higher probability for chipping than monolithic prostheses. Probability of chipping was similar for micro-veneered single-unit, multi-unit, and complete-arch zirconia prostheses.

Clinical outcomes of implant-supported monolithic zirconia crowns and fixed partial dentures: A systematic review

PURPOSE

To determine the survival rates of implant-supported monolithic zirconia crowns and fixed partial dentures (FPD).

MATERIAL AND METHODS

An electronic search for articles in the English language literature published from January 1, 2001 to September 17, 2021 was performed using PubMed, Scopus, and CENTRAL search engines. After applying predetermined inclusion and exclusion criteria, the definitive list of selected articles was used for calculating the interval survival rate (ISR) and cumulative survival rate (CSR). Restoration failure in this study was defined as the fracture or compromise of any part of the ceramic restoration that required the removal or remake of the implant-supported restoration.

RESULTS

The electronic search resulted in 457 titles. The systematic application of inclusion and exclusion criteria resulted in 14 clinical studies that addressed the clinical outcomes of implant-supported monolithic zirconia crowns and fixed partial dentures. Of these, 3 were randomized controlled trials, 5 were prospective studies, and 6 were retrospective studies. Follow-up periods ranged from 1 to 5 years. Of the 644 implant-supported monolithic zirconia restorations computed in this systematic review, there was only 1 reported failure of the monolithic zirconia restorative material over a follow-up period of up to 5 years, for a cumulative survival rate of 99.84%. At the maximum follow-up interval of 5 years, the cumulative survival rate for monolithic zirconia single crowns was 100% and the cumulative survival rate for monolithic zirconia fixed partial dentures was 99.60%.

CONCLUSIONS

Implant-supported monolithic zirconia single crowns and fixed partial dentures have excellent short-term (<5 years) survival rates but the evidence for medium-term survival (>5 years) and beyond is lacking.