Evaluation of Microleakage of a New Bioactive Material for Restoration of Posterior Teeth: An In Vitro Radioactive Model

Abstract

Hybrid bioactive composite resins combine the benefits of glass ionomer cements with composite resins. Its self-adhesiveness is achieved through functional polyacrylic acids and carboxylic groups, hybridizing the smear layer and establishing ionic interactions between calcium and dentin. These materials are defined as having good aesthetics, moisture tolerance, durability, simplicity in technique and handling and are able to maintain a low microfiltration rate while releasing calcium, phosphate and fluorine. The aim of the present study was to evaluate microleakage in restorations using Surefill One™ bioactive resin. The null hypothesis is that this type of resin does not obtain a lower microleakage rate when compared to other materials. An in vitro study was carried out using thirty-six premolars and molars extracted for orthodontic reasons. Identical preparations were thus performed in all of them (Class V with 4 mm mesio-distal, 3 mm occluso-gingival and 3 mm in depth) and divided into different experimental groups: one positive control, one negative control and two tests with bioactive composite resin and conventional composite resin (Surefill One™ and Spectra™ ST HV, respectively). Through quantitative techniques using nuclear medicine, it was possible to evaluate microleakage through the use of a radioactive isotope, technetium. Radioactivity emitted by the specimens was detected by a gamma camera. The different groups were compared using the Kruskal–Wallis test and the Games–Howell test for multiple comparisons. The results of the experimental study point to statistically significant differences between the test groups (p = 0.002) with increased microleakage in the bioactive composite resin group. Based on the present microleakage study, it was possible to conclude that the bioactive composite resin (Surefill One™) does not reduce the microleakage rate when compared to a conventional nanohybrid composite resin (Spectra™ ST HV). However, Surefill One™ can be used in temporary restorations, primary teeth and in cases of tissue remineralization, thus avoiding more invasive procedures.