Longevity of bonded composite restorations after dentin biomodification with neolignans obtained from Nectandra leucantha

Abstract

Objective: This in vitro study evaluated the effect of neolignan-containing solutions on dentin biomodification previously applied to the bonding procedure in adhesive restorations. Material and Methods: Neolignans, dehydrodieugenol B-CP1 and dehydrodieugenol B methyl ether-CP2, were isolated from Nectandra leucantha and two aqueous solutions containing 0.13% neolignans, 0.2% propylene glycol and 3.0% ethanol were prepared. Bovine teeth were ground flat to obtain 2-mm thick specimens which received resin composite restorations (N=10). The neolignan solutions were applied before the bonding procedure (60 s). Experimental groups were: control, untreated group, 0.12% chlorhexidine gel, 0.13% CP1 solution, and 0.13% CP2 solution. A push-out bond strength test was conducted (0.5 mm/min). Bovine tooth sections (0.5×1.7×7.0 mm) were also obtained to assess the modulus of elasticity and mass change after treatment (N=15). A three-point bending test evaluated the elastic modulus of fully demineralized dentine beams after immersion in the solutions. The data were statistically analyzed (α = 0.05). Results: The bond strength of the restorations to dentin was significantly improved by the treatment with neolignan-containing solutions, irrespective of the evaluation time (p<0.05). After 6 months, a significant reduction in the bond strength was observed in the groups treated with the solutions (p>0.05), but the means were significantly higher than the control groups (p<0.05). The elastic modulus of demineralized dentin was significantly improved after the treatment with the solutions (p<0.05). All groups lost mass weight. Conclusion:The solutions improved the in vitro longevity of bonded restorations, possibly due to the dentin biomodification effect of the neolignans.

Influence of two natural cross-linkers on microtensile bond strength durability An in vitro study

“…The inherent collagen cross-linking contributes to the stability, strength, and function of the dentin matrix [15]. The application of exogenous collagen cross-linkers (Dentin biomodification) induces additional inter and intramolecular cross-links of collagen that aid not only in strengthening the dentin matrix but also decreasing the biodegradation rate [16,17]. Several synthetic and natural collagen cross-linkers have been extensively studied to improve the mechanical properties of demineralized dentin [18][19][20].…”