Methods: One hundred and eight extracted third molars were used to prepare dentin beams. Beams (1x2x6mm) were completely demineralised in 10% phosphoric acid (24h). After baseline measurements of dry mass, beams were divided into 12 groups (n=9/group). The groups were incubated in 1mL calcium and zinc containing incubation media (CM) containing 1) glutaraldehyte 1% (GA), 2) GA 5%, 3) grape-seed extract (GS, 1%), 4) GS 5%, 6) riboflavin/UV (R, l%), 7) R 5% 8) sumac (S, 10%), 9) riboflavin-5-phosphate/UV (RP, 0,1%) and 10) curcumin (CR, 20µM) 11) CR -200µM at 37ºC in shaking bath. The CM only incubation without any crosslinker addition was used as control group (CM). Beams were dried and re-weighed to determine loss of dry mass following 3 and 7 days of incubation. Aliquots of the incubation media were analyzed for pyridinoline-crosslink-containing degradation fragment of the C-terminal telopeptide of type I collagen (ICTP) and deoxypyridinoline-containing degradation fragment of the C-terminal telopeptide region of type I collagen (CTX) using ELISA immunoassay kits. Data were analyzed using ANOVA and Tukey’s test.
Results: The rate of dry mass loss changed significantly between different groups. The lowest mean weight loss was observed at GA5%=0.01±0.70; compared to control (CM=-8.35%±0.75), p<0.05). The ICTP release ranged between 20-40 (ng/mg dentin), GS and CR showed significantly lower release compared to control. Similarly, CTX release (pg/mg dentin) of all crosslinkers was lower than the control.
Conclusions: The results of this study clearly indicate that addition of collagen crosslinkers in the incubation media resulted in a significant decrease in dentin collagen degradation.