Biomodification of Demineralized Dentin with an Experimental Flavonoid

Objectives: Dentin structural changes induces by acid conditioning decrease microtensile strength (μTS) and elastic modulus (E) due to incomplete infiltration of resin monomers inside matrix-collagen fibrils, hydrolityc degradation and varying degree of demineralization of intertubular and peritubular dentin. It has been observed a stress concentration zone next to the exposed-collagen layer produced by the considerable reduction of elastic modulus in demineralized dentin, which contributes to decrease the longevity and stability of the resin-dentin interface. The aim of this study was to evaluate the effect of experimental flavonoid (FLV-1) on μTS and E of demineralized dentin.


Methods: Fiveteen extracted third molars were obtained with informed consent. The samples were stored in 0,9% sodium chloride and 0,02% sodium azide solution. Dentin beams of 1mm² of adhesion area were randomly allocated into 6 groups: mineralized dentin (DM), demineralized dentin (DD), 100% ethanol (ETH), 0,02% chlorhexidine (CXH), 1% glutaraldehyde (GA) and an experimental flavonoid (FLV-1). The samples of each group were tested by the μTS test and E was calculated. The results were statistically analyzed to evaluate normal distribution by Shapiro Wilk and significant difference between groups by ANOVA, followed by Tukey post hoc and Pearson correlation test, (p≤0,05).

Results: Human dentin μTS and E were notably decreased after acid conditioning. Dentin-resin strength significantly increased following treatment with cross-linkers. The FLV-1 showed the highest μTS (14,74 Mpa)(p<0,001) followed by GA (14,36 Mpa) (p<0,001), while CHX had the lowest values (8,00 Mpa ) (p<0,885). Regarding E values, GA obtained the highest (118,10 Mpa) (p<0,006) followed by FLV-1 (88,88 Mpa) (p<0,237) compared to control group (DD). Additionally, a linear correlation was found between μTS and E in FLV-1 group (p<0,001).

Conclusions: Increased mechanical properties and stability of dentin matrix can be achieved by the use of cross-linkers like FLV-1. Changes to the dentin matrix positively affected the μTBS and E.