In vitro and in vivo performance of self-conditioning sealants with pre-reacted glass for caries prevention

Abstract

Bioactive materials capable of preventing the development of caries lesions can be an important preventive strategy. This study aims to evaluate in vitro the alkalizing potential, fluoride release, shear bond strength (SBS), and Knoop microhardness (HK) of self-conditioning sealants with pre-reacted glass (S-PRG) and in vivo their retention, quality and caries prevention using the randomized clinical trial (RCT). Dental sealants FS-conventional (Fluoroshield-Dentsply) and BS self-etching (BeautiSealant-Shofu) were evaluated. Sealants samples (n = 5 per group) were performed to verify the alkalizing potential and fluoride release at neutral and acid pH. For mechanical evaluation of both sealants, twenty bovine incisors were used for SBS test, and twenty sealant samples were performed for HK under 50 g load for 15 s. All measurements were taken after 24h and 30 d. A split-mouth RCT including 28 volunteers (10–14 years) with erupted permanent molars and initial enamel caries lesions was conducted to evaluate BS and FS behavior. Sealant retention (total, partial and total loss) and quality scores were analyzed after 30 d. In vitro and in vivo tests were assessed by T-test, and χ2 & Fisher tests (α = 0.05). BS demonstrated higher alkalinizing potential at neutral and acid pH and lower SBS and HK at 24h and 30 d (p < 0.05). However, the FS had greater fluoride release at neutral and acid pH. Clinically, BS also showed lower retention than FS (p = 0.02), but no sealant quality difference was observed. Both sealants contributed to the remission or non-evolution of caries. After 1 month, the bioactive S-PRG sealant showed in vitro a higher alkalizing potential and lower fluoride release, retention, and microhardness, while in vivo, despite the lower retention, the non-evolution of caries lesions was verified.