Practice-based analysis of direct posterior dental restorations performed in a public health service: Retrospective long-term survival in Brazil.

The aim of this retrospective study was to evaluate the survival and associated factors for the longevity of direct posterior restorations and to verify whether the geographic location of public health units could influence the long-term survival of such restorations. Data were extracted from electronic patient files of the Brazilian public oral health services. The sample comprised 2,405 class I and II restorations performed 4 to 24 years ago (mean, 8.9 years) in 351 patients (6.8 teeth/patient) across 12 public health units located in different city regions (42 professionals-55 restorations). The restoration was considered successful if it had not been repaired or replaced at the time of evaluation; failure was defined as replacement of the restoration, the need for endodontic treatment, tooth/restoration fracture or tooth extraction. Data were analyzed using the Kaplan-Meier test for restoration survival and Cox regression to evaluate the factors associated with failure. The majority of the restorations involved the use of amalgam (85%), involved a single face (70%), and were without pulp/dentin capping (85%). The overall survival rate was 95%, and the mean observation time was 8.9 years. The restoration survival was 79% (95% CI: 60.6-89.5) over 24 years, and the mean survival time was 22.2 years (95% CI: 21.9-22.6 years). The annual failure rate up to 24 years was 0.9%. After the adjustment, only the number of restored faces and the geographic location where the restoration was performed remained associated with failure of the restoration. The direct posterior restorations performed at the evaluated public health service units presented high survival rates. The restorations of people with lower access to POHS had lower survival rates. Class I restorations presented higher survival rates than class II restorations with two or more faces, regardless of the restorative material used.

The new generation of conventional and bulk-fill composites do not reduce the shrinkage stress in endodontically-treated molars.

PURPOSE: To compare flowable and regular paste bulk-fill resin composites with old and new generation conventional composites that use incremental filling techniques for direct restoration of endodontically-treated teeth. METHODS: Four resin composites produced by the same company (3M-ESPE) were used: two conventional resin composites (old formulation, Z100, and new nanofilled formulation, Filtek Supreme XT); and two bulk-fill resin composites (flowable composite, Filtek Bulk-fill Flowable associated with Filtek Supreme, and regular paste, Filtek Bulk-fill Posterior). Elastic modulus (E), Vickers hardness (VH), post-gel shrinkage (Shr), diametral tensile strength (DTS) and compressive strength (CS) were determined (n= 10) and statistically analyzed using ANOVA and Tukey's test (α=0.05). Shrinkage stresses were analyzed using non-linear finite element analysis. RESULTS: Filtek Bulk-fill flowable and Filtek Supreme XT had higher CS than Z100 and Filtek Bulk-fill Posterior. Z100 and Filtek Supreme XT had higher DTS than Filtek Bulk-fill Posterior. Filtek Bulk-fill flowable had the lowest values and Z100 the highest E and Shr. Z100 resulted in higher stresses in the enamel and in root dentin close to the pulp chamber than the other filling techniques. Filtek Bulk-fill Flowable resulted in lower stress than other resin composites. CLINICAL SIGNIFICANCE: Using bulk-fill composites, especially flowable resin composite, created lower stresses in restored endodontically-treated teeth. Clinicians, when deciding for direct restoration of endodontically-treated teeth, may choose the bulk-fill composite to decrease undesirable effects of direct restoration while simplifying filling procedure.