白皮杉醇对乳牙脱矿牙本质基质生物改性的研究OA

Objective To investigate the ability of different concentrations of piceatannol(PIC)solution to bio-modify decalcified dentin matrices in primary teeth,thereby providing a theoretical basis for improving the durability of resin-dentin bonding.Methods This study was approved by the Medical Ethics Committee of the institution.Mo-lecular docking was performed to predict the interaction effects of PIC with type I collagen and matrix metalloprotein-ases(MMPs)in dentin.A total of 124 clinically extracted intact primary molars were selected due to retention;of these,76 were prepared into 60 completely decalcified dentin beams and 24 dentin slices.The 60 beams were equally allo-cated for dry mass loss and swelling ratio testing(30 beams each).For both experiments,the beams were randomly di-vided into five groups(n=6):a control group,5％glutaraldehyde group,and 2.5,5,and 10 mg/mL PIC solution groups.This was to evaluate the anti-enzymatic hydrolytic properties and mechanical performance of type I collagen.Of the 24 slices,15 were assigned to the aforementioned five groups(n=3)for Fourier-transform infrared spectroscopy(FTIR)to explore the cross-linking mechanism.The remaining nine slices were randomly divided into three groups(n=3):dis-tilled water group A(SEM examination prior to enzymatic hydrolysis),distilled water group B(SEM examination after enzymatic hydrolysis),and a 10 mg/mL PIC solution group(SEM examination after treatment with 10 mg/mL PIC and subsequent enzymatic hydrolysis).This was to evaluate the cross-linking effect on demineralized dentin collagen.The remaining 48 molars were fabricated into bonding specimens and randomly divided into four groups(n=12):a control group(distilled water group)and 2.5,5,and 10 mg/mL PIC groups.Immediate and aged shear bond strength(SBS)were measured,and failure modes were observed under a stereomicroscope to investigate the impact of different PIC concen-trations on the bonding durability of primary tooth dentin.Results Molecular docking revealed strong binding activity between PIC and type I collagen/MMPs via hydrogen bonds,electrostatic potential,and hydrophobic forces;the FTIR results confirmed hydrogen bond formation.In the dry mass loss test,mass loss rates in the 2.5,5,and 10 mg/mL PIC groups were significantly lower than that in the control group(P<0.05),with the 10 mg/mL PIC group showing the most optimized cross-linking effect.Swelling tests indicated that all three PIC concentrations reduced the swelling ratio of the demineralized matrix,effectively improving its mechanical properties.SEM showed that collagen from the 10 mg/mL PIC group retained its natural three-dimensional network post-enzymolysis,contrasting sharply with the disinte-grated collagen in the enzymolyzed distilled water group B but resembling the morphology of the non-enzymolyzed dis-tilled water group A.SBS results demonstrated that the 10 mg/mL PIC group exhibited significantly higher bond strengths than the control group in both the immediate and aged tests(P<0.05);immediate SBS in the 10 mg/mL PIC group was also significantly greater than that in the 2.5 mg/mL PIC group(P<0.05),while no other intergroup differ-ences were found(P>0.05).Failure mode analysis indicated predominantly mixed fractures,with the proportion of in-terfacial fractures decreasing as PIC concentration increased compared with the control group.Conclusion A 10 mg/mL PIC solution can effectively cross-link decalcified dentin matrices in primary teeth,enhancing the anti-enzymatic hydrolytic capacity and mechanical properties during clinical operation,thereby promoting bond strength and interface stability,which promises to improve the long-term durability of resin-dentin bonding.