Effect of green tea extract on bonding durability of an etch-and-rinse adhesive system to caries-affected dentin

Abstract

Objective Green tea extract has been advocated as a matrix metalloproteinase (MMP) inhibitor; however, its effect on bond durability to caries-affected dentin has never been reported. Thus, the aim of this in vitro study was to evaluate the effect of two MMP inhibitors (2% chlorhexidine and 2% green tea extract), applied after acid etching, on bond durability of an etch-and-rinse adhesive system to caries-affected dentin.Material and Methods Occlusal enamel was removed from third molars to expose the dentin surface, and the molars were submitted to a caries induction protocol for 15 days. After removal of infected dentin, specimens were conditioned with 37% phosphoric acid (15 seconds) and randomly divided into three groups, according to the type of dentin pretreatment (n=10): NT: no treatment; GT: 2% green tea extract; CLX: 2% chlorhexidine. The etch-and-rinse adhesive system (Adper™ Single Bond 2, 3M ESPE, St. Paul, MN, USA) was applied according to the manufacturer's instructions, and composite resin restorations were built on the dentin. After 24 hours, at 37°C, the resin-tooth blocks were sectioned perpendicularly to the adhesive interface in the form of sticks (0.8 mm2 of adhesive area) and randomly subdivided into two groups according to when they were to be submitted to microtensile bond strength (μTBS) testing: immediately or 6 months after storage in distilled water. Data were reported in MPa and submitted to two-way ANOVA for completely randomized blocks, followed by Tukey’s test (α=0.05).Results After 24 hours, there was no significant difference in the μTBS of the groups. After 6 months, the GT group had significantly higher μTBS values.Conclusion It was concluded that the application of 2% green tea extract was able to increase bond durability of the etch-and-rinse system to dentin. Neither the application of chlorhexidine nor non-treatment (NT - control) had any effect on bond strength after water storage.

Aplicação dos sistemas adesivos nos últimos cinco anos

“…Carvalho et al 51 estudaram em 2016, os efeitos do extrato de chá verde, na durabilidade da adesão de adesivos autocondicionantes, em dentina afetada. Seu estudo concluiu que a aplicação do extrato de chá verde como inibidor de metaloproteinases age de forma favorável a adesão.…”

Recent Advances in Adhesive Bonding: The Role of Biomolecules, Nanocompounds, and Bonding Strategies in Enhancing Resin Bonding to Dental Substrates

“…Proanthocyanidins are natural crosslinkers derived from polyphenols, which are able to enhance the mechanical properties of dentin, thus improving the quality of the hybrid layer (23, 27, 28). The incorporation of proanthocyanidin to an experimental adhesive did not show adverse effects on the immediate resin-dentin bond strength when its concentration was less than or equal to 2% (29).…”

“…Finally, but no less important, polyphenols (e.g., proanthocyanidins, genipin, epigallocatechin gallate), benzalkonium chloride, and quaternary ammonium methacrylate polymer have all demonstrated effective protease inhibition potential (27, 69–72). It was suggested that these agents may reduce dentin biodegradability of host-derived MMPs, thus improving the quality of the hybrid layer.…”

“…It was suggested that these agents may reduce dentin biodegradability of host-derived MMPs, thus improving the quality of the hybrid layer. According to this review, these agents may be applied after acid-etching (27), during the priming step as modified primers (69, 70), or during the bonding step as modified resin adhesives (71, 72). …”

The Efficacy of Riboflavin for Collagen Cross-Linking and Optimizing the Bond Strength of an Etch and Rinse Adhesive System to Dentin

“…These collagen fibrils are more susceptible to creep and degradation due to cyclic fatigue after long-term function (2). On the other hand, matrix metalloproteinases (MMPs) are exposed and activated by acidic agents during the bonding process and since they play a role in the degradation of type I collagen, which is the organic component of the hybrid layer, they can gradually break down collagen fibrils at the resin-dentin interface (3)(4)(5)(6)(7).…”