PURPOSE: To evaluate the survival rate of full-coverage tooth-supported fixed prosthetic restorations, single crowns (SCs), and fixed dental prostheses (FDPs), taking into consideration the potential influence of tooth-vitality, presence and type of post, and type of prosthetic restoration material.

MATERIALS AND METHODS: In October 2022, two authors independently conducted a search in PubMed, Web of Science, and Scopus electronic databases as well as a hand search to identify clinical human studies on full-coverage SCs and FDPs supported by vital and/or non-vital abutments and/or a combination of both, with a minimum observation period of 24 months.

RESULTS: Out of 4198 studies identified through the database search and 22 through hand searching, 26 studies fulfilled the inclusion criteria and were included in the analysis of the present systematic review. Included studies scored six points and more according to Newcastle-Ottawa Scale (NOS). The highest estimated 5-year survival rate was observed for (metal-ceramic and all-ceramic) SCs on vital teeth (98.3%; 95% CI [98.1, 98.6%]) and all ceramic SCs on non-vital teeth with fiber post (95.0%; 95% CI [94.5-95.4%]). Metal-ceramic SCs on vital teeth (97.1%; 95% CI [95.6-98.7%]) showed a statistically significant higher estimated 5-year survival rate compared to metal-ceramic SCs with cast metal post (90.7%; 95% CI [87.4-94.0%], P < 0.001), fiber post (91.3%; 95% CI [90.9-91.6%], P < 0.001) and without post (85.7%; 95% CI [80.7, 90.6%], P < 0.032). All-ceramic SCs with fiber post had a statistically significant higher estimated 5-year survival rate (95.0%; 95% CI [94.5-95.4%]) compared to metal-ceramic SCs on non-vital teeth with fiber post (91.3%; 95% CI [90.9-91.6%], P < 0.001). SCs (all-ceramic and metal-ceramic) with fiber post had a statistically significantly higher estimated 5-year survival rate of (92.7%; 95% CI [92.4-92.9%]) than SCs made of metal-ceramic and retained by cast metal post (90.7%; 95% CI [87.4-94.0%], P < 0.001). For FDPs, the 5-year survival rate was significantly higher for FDPs on vital abutments (84.9%; 95% CI [75.9, 93.9%]) compared to FDPs retained by non-vital abutment/s (81.3%; 95% CI [80.3, 82.2%], P = 0.049) irrespective to presence, type of post, and FDPs material. The results are limited by the limited number of studies and the presence of uncontrolled confounding clinical variables.

CONCLUSIONS: Within the limitations of the study, tooth vitality is suggested to contribute positively to the survival of SCs and FDPs.

PURPOSE: To assess the influence of several factors on the survival of tooth-supported fixed partial dentures (FPDs) with vital and non-vital abutments.

MATERIALS AND METHODS: The present retrospective cohort study was based on the records of patients treated with 3-to-7-unit tooth-supported FPDs with a minimum follow-up time of 6 months after prosthesis delivery. Cumulative survival rate (CSR) was calculated over the maximum follow-up period. Cox regression models were used to evaluate the association between the clinical covariates and prosthesis failure.

RESULTS: A total of 331 FPDs in 229 patients were included. The CSRs were 90.1% and 77.6% after 5 and 10 years and 67.9% and 52.1% after 15 and 20 years, respectively. Tooth-supported FPD failure was more prevalent within the first years of prosthesis delivery. Loss of one or more abutment teeth and loss of prosthesis retention were the main reasons for failure. Smoking and type of prosthesis material significantly influenced the survival of FPDs. Abutment vitality, position of the non-vital abutment, or prosthesis length did not show any significant influence on the occurrence of prosthesis failure.

CONCLUSION: Smoking and the type of prosthesis material are suggested to contribute to an increased rate of FPD failure irrespective of abutment vitality.

Background: Tooth-supported fixed dental prosthesis (FDP) is one of the most reliable treatment options to replace missing teeth. The longevity of the treatment could, however, be affected by several general and local factors, especially bruxism.

Objective: To investigate the influence of bruxism on the long-term survival of tooth-supported FDPs in bruxers compared to a matched group of nonbruxers, taking several clinical variables into account.

Materials and methods: The present retrospective cohort study was based on records of patients treated with 3-7-unit tooth-supported FDPs with a minimum follow-up time of 6 months after prosthesis delivery. The criteria for the diagnosis of "possible" and "probable" sleep or awake bruxism were used. A matched group of nonbruxers was selected on the basis of similarities in four factors, patients' gender and age, number of prosthetic units of the FDPs, and follow-up time. The paired-samples t-test or Wilcoxon signed rank test were used to compared mean values between the two groups. Contingency tables of categorical data were analyzed by McNemar's test.

Results: The cohort group consisted of 62 noncantilevered FDPs in each group, followed up for a mean of 110.1 and 106.5 months (bruxers and nonbruxers, respectively). Tooth-supported FDPs in bruxers presented significantly higher failure rate than in nonbruxers (32.3% vs. 25.8%, respectively; p = 0.001). Loss of retention and tooth loss were the main reasons for failures in both groups. For nonsmokers, the FDP failure rate was higher in nonbruxers. Technical and biological complications were significantly more prevalent in bruxers compared to nonbruxers.

Conclusions: Bruxism is suggested to increase technical and biological complications and FDP failure.

The purpose of the study was to investigate the influence of multiple factors on the survival of tooth-supported single crowns and assess the biological and technical complications. This retrospective study included patients rehabilitated with single crowns with a minimum follow-up time of 6 months after delivery. The cumulative survival rate was calculated over the maximum period of follow-up time and reported in a life-table survival analysis. Univariate and multivariate Cox regression was used to evaluate the associations between clinical covariates and crown failure. The included cohort group consisted of 1037 single crowns delivered in 401 patients and followed for a mean of 134.8 ± 80.2 months. Cumulative survival rate was 89.9% and 80.9% after 5 and 10 years and 70.5% and 61.8% after 15 and 20 years, respectively. The main reasons for single crown failure were loss of retention, tooth loss, and fracture. Anterior placement, non-vital abutments, and bruxism significantly influenced the survival of single crowns. The survival of single crowns was not influenced by patient's age and sex, location of the crowns in relation to the jaws, type of tooth, presence of post and core, and type of crown material, treatment providers, or smoking. Anterior placement, non-vital abutments, and bruxism are factors suggested to increase the risk of single crown failure and the prevalence of technical and biological complications.