Influência da resina flow como material intermediário na longevidade de restaurações em dentes posteriores

Abstract

The composite resins have been used in restorations of posterior teeth since 1970, allowing more esthetic and minimally invasive treatments. Today, composite resins are considered the first-choice direct material for restorations on posterior teeth. However, this material has a sensitive technique, presenting polymerization contraction and difficult material insertion characteristics. These characteristics may influence mainly the insertion and adaptation of the material in the proximal and cervical region of restorations in posterior teeth. Thus, as an alternative to minimize such limitations, a more fluid restorative material such as an intermediate layer, base or liner, below the composite resin, may be used as a composite resin of the flow type. The objective of the present study was, through a longitudinal retrospective clinical study, to evaluate the clinical performance of composite resin restorations on posterior teeth with a flow resin layer as an intermediate material, compared to conventional composite resin restorations on posterior teeth. For this, data were collected regarding composite resin restorations in posterior teeth that used as flow resin intermediate material and also conventional composite resin restorations as a comparison. Data were collected from records of a private dental office located in the city of Caxias do Sul / RS. The data collection of the medical records was performed by four independent, previously trained typists. The data was extracted into a database in the Excel program. The data were tabulated and submitted to statistical analysis, which was performed using Stata 12.0 software (StataCorp LP, College Station, TX, USA). Statistical analysis was performed using log rank test, Kaplan Meier and Cox regression (p <0.05). The study included 79 patients, totaling 237 restorations in the study. The annual rate of failure of restorations with intermediate layer of resin flow over 5 years was 4.4%, while the annual failure rate of conventional restorations was 9.1%, presenting a statistically significant difference (p = 0.06). However, this difference was not consistent after adjusting the analysis for patient's sex, tooth type and adhesive system (p = 0.20). The only factor that remained to affect the longevity of the restorations after adjustment of analysis was the type of adhesive system used, favoring the use of Clearfill SE Bond in comparison with other adhesive systems (p = 0.06). The use of flow resin as an intermediate material has an effect on the longevity of the restorations, but it seems to be influenced by other factors, such as the type of adhesive system or the type of tooth.