Investigating a Commercial Functional Adhesive with 12-MDPB and Reactive Filler to Strengthen the Adhesive Interface in Eroded Dentin

Abstract

To compare the adhesive interface of eroded dentin formed by a functional dental adhesive and a gold standard strategy, by testing microtensile bond strength (μTBS), hardness/elastic modulus. Permanent sound human molars were randomly allocated to four experimental groups, all subject to artificial erosion (0.05 M citric acid; 3× daily, 5 days). Groups included control Clearfil SE Bond 2 (CFSE), and experimental group Clearfil SE Protect (CFP), at two different time points-immediate (24 h) and long term (3 months–3 M). Samples were sectioned into microspecimens for μTBS (n = 8) and into 2-mm thick slabs for nanoindentation assays (n = 3). Groups CFSE_3M and CFP_3M were stored in artificial saliva. Statistical analysis included two-way ANOVA for μTBS data, while hardness/modulus results were analyzed using Kruskal–Wallis H Test (significance level of 5%; SPSS v.27.0). Although no significant differences were found between mean μTBS values, for different adhesives and time points (p > 0.05), a positive trend, with μTBS rising in the CFP_3M group, was observed. Regarding hardness, no significant differences were seen in the hybrid layer, considering the two variables (p > 0.05), while the reduced elastic modulus rose in CFP_3M when compared to 24 h. Thus, CFP shows similar mechanical and adhesive performance to CFSE in eroded dentin, although it may comprise promising long-term results. This is advantageous in eroded substrates due to their increased enzymatic activity and need for remineralization.

Effect of Collagen-Reactive Functional Monomer on Etch-and-Rinse Adhesives

“…Direct inhibition of endogenous proteolytic activity and exogenous cross-linking of fibers can reduce the degradation of the collagen matrix (Bedran-Russo et al 2014; Breschi et al 2018). Researchers have been focusing on inhibitors that can be incorporated into adhesives to reduce chair time and facilitate copolymerization while imparting multifunctional properties to the adhesives (Imazato et al 2014; Belmar da Costa et al 2021; Wu et al 2022). The essential issue of the absence of resin–collagen covalent bonding can be addressed by chemically derivatizing the acrylate ester ends in a proven cross-linker molecule (Van Meerbeek et al 2011; Giannini et al 2015).…”