Resinas compostas pré-aquecidas como agente de cimentação: uma revisão sistemática de estudos in vitro

Abstract

This systematic review was conducted to investigate the performance of preheated composite resins compared to flowable composite resins, and resin cement as luting agents. This study has also given an overview of the properties related to the luting procedure with these different materials whose performance was presented herein. A search of studies that investigated the influence of Preheated composite resin used as a luting agent on the properties such as degree of conversion, film thickness, marginal adaptation, viscosity, color stability, polymerization shrinkage, bond strength and flexural strength was conducted. PubMed, Web of Science, Embase, Scopus, and National database – “Biblioteca Virtual em Saúde” (BVS) databases were explored until April 2021 with no year limit. The included studies must have at least an intervention group (preheated resin composite) and a control group (flowable resin composite and/or dual or light-cured resin cements). Studies that evaluated only materials currently unavailable on the market, experimental materials, orthodontic devices bonding, or preheated composite as a restorative material were excluded. Data regarding resin-based luting agents’ properties aforementioned were collected. A metaanalysis was not possible due to heterogeneity of data. A qualitative analysis of results was conducted, identifying factors associated to performance of preheated composite resins. The following parameters were analyzed to evaluate the risk of byas: sample size calculation, randomization, standardized sample preparation, materials used according to the manufacturer’s instructions, blinded operator during the test, complete data report, blinded data analysis, statistical analysis carried out. After duplicates’ removal, 703 studies were identified, 34 were selected for full-text analysis, and 28 remaining papers met the inclusion criteria and were included in this systematic review. No clinical studies that met the inclusion criteria were found, so the review was restricted to in vitro studies. High variability was observed in the included studies. Viscosity and film thickness were greatly affected by temperature increase for most of the resin composites, but still not able to produce less viscous or thinner film thickness as flowable composites or resin cements. Marginal adaptation of indirect restorations has shown contrasting results, as some studies observed better seating when cemented with preheated composite, while resin cement and flowable composites provided better marginal adaptation in others. Many contrasting results were also observed regarding the influence of preheating resin composite on polymerization shrinkage, degree of conversion, bond strength, and color stability. Clinical studies to establish preheated composite resins as a luting agent are essential since this material presented similar results in comparison with flowable composite resins or resin cement. CRD 42019120459. Preheated composite resins present potential benefits to be applied as a luting agent, but should be used with an awareness of its limitations and the countless factors that may influence its clinical performance. It must be addressed that preheating resin composite requires the purchase of a heating device, and also a learning curve due to the high technical sensitivity procedure