Objective: To investigate the ability of different concentrations of piceatannol (PIC) solution to biomodify 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. Molecular docking was performed to predict the interaction effects of PIC with type I collagen and matrix metalloproteinases (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 allocated for dry mass loss and swelling ratio testing (30 beams each). For both experiments, the beams were randomly divided 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): distilled 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 concentrations 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 disintegrated collagen in the enzymolyzed distilled water group B but resembling the morphology of the non-enzymolyzed distilled 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 differences were found (P > 0.05). Failure mode analysis indicated predominantly mixed fractures, with the proportion of interfacial 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.

Objective To evaluate the impact of ultra-high-molecular-weight polyethylene(UHMWPE)-Ribbond fi-bers,when combined with different restorative materials,on fracture resistance and marginal adaptation of isolated pri-mary molar defects,to provide a reference for clinical practice.Methods This study was approved by the Ethics Re-view Committee.A total of 72 extracted primary molars with complete crowns were collected,and 66 primary molars were randomly assigned as experimental groups for the fracture resistance and microleakage tests.The molars were di-vided into six groups(n=11)based on the type of restorative materials and the application of Ribbond fibers:Group A1,3M Filtek Z250+Ribbond;Group A2,3M Filtek Z250;Group B1,Beautifil Ⅱ LS+Ribbond;Group B2,Beautifil Ⅱ LS;Group C1,3M Filtek Bulk Fill+Ribbond;and Group C2,3M Filtek Bulk Fill.Groups A1,B1 and C1 received the fiber-reinforcing technique,whereas Groups A2,B2 and C2 received the direct restorative technique;the remainings were in Group D(blank control group),which did not receive treatment for the fracture resistance test.The fracture re-sistance test was divided into six experimental groups and one blank control group(n=6).Primary molar teeth in each experimental group were prepared with Class Ⅱ cavities and filled.The fracture load of all samples was detected,and the fracture mode was analyzed after thermal cycling.The microleakage test was divided into six experimental groups,with five in each group.Class Ⅰ cavities with a diameter of 3 mm and depth of 2.5 mm were prepared within the mesial and distal marginal ridges on the occlusal surface and filled for primary molars in each group.Marginal microleakage was assessed after thermal cycling.Results The fracture resistance test results showed that the fracture resistance in groups that received the fiber-reinforcing technique was greater than that in groups that received the direct restorative technique:Group A1>Group A2,Group B1>Group B2,Group C1>Group C2(P<0.05).The application of Ribbond fibers increased fracture resistance to all tested restorative materials by 37.08％to 39.34％.The proportion of tooth frac-ture decreased significantly in groups A1,C1 compared with A2,C2,with a significant increase in the occurrence rate of"Repairable"(P<0.05).The fracture resistance in Group A1 was significantly greater than that in Group B1 and Group C1(P<0.05).The marginal microleakage test results showed that the microleakage depth in groups that received the fiber-reinforcing technique was smaller than that in groups that received the direct restorative technique:Group A1

Objective : To explore the effects of two hemostatic agents on the bonding strength of different bonding systems in primary tooth dentin. Methods : Seventy-two retained deciduous teeth were randomly selected. Forty-eight teeth were used to construct the microleakage model, the other 24 teeth were cut along the mesial and distal directions and 48 samples were obtained to construct the shear bond strength model. The two experiments were divided into 2 groups. Group A was the total-etch group: A1 (ViscoStat + Spectrum Bond NT); A2 (ViscoStat Clear + Spectrum Bond NT); and A3 (Non + Spectrum Bond NT); Group B was the self-etch group: B1 (ViscoStat + Single bond Universal Adhesive); B2 (ViscoStat Clear + Single bond Universal Adhesive); and B3 (Non + Single bond Universal Adhesive). Microleakage experiments and shear bond strength experiments were carried out respectively and the morphology of the fracture surface was observed by scanning electron microscopy. Results : There was no significant difference in microleakage among groups A1, A2, and A3 (P > 0.05). There was no significant difference in microleakage among groups B1, B2, and B3 (P > 0.05). There was no significant difference in the shear bond strength among groups A1, A2 and A3 (P > 0.05). The shear bond strength of groups B1 and B2 was significantly lower than that of group B3 (P < 0.05). There was no significant difference between groups B1 and B2 (P > 0.05). Conclusion ViscoStat and ViscoStat Clear had no effect on the marginal integrity of deciduous tooth dentin under the different bonding systems. The two hemostatic agents reduced the shear bonding strength of deciduous tooth dentin under the self-etch adhesive system, but had no effect on the shear bonding strength of deciduous tooth dentin under the total-etch adhesive system.

Objective To investigate the role of autophagy and synaptophysin (SYP) in cognitive impairment in de?pressed rats receiving electroconvulsive shock (ECS). Methods Clean and healthy adult male Sprague-Dawley rats were acclimatized to a standard laboratory environment for 7 days. The chronic unpredictable mild stress (CUMS) was used to establish the rat model of depression. Behavior tests were conducted before and after CUMS to evaluate the depression and cognition level of rats. After establishment of the model, 24 rats were randomly divided into ESC group (group E) and depression group (group D) with 12 rats in each group. The rats in group E were administered 80 mg/kg of propofol (10 mg/mL) by intraperitoneal injection, followed by ECS treatment. The rats in group D were administered propofol by intra?peritoneal injection, followed by sham-ECS treatments. The above interventions were conducted daily for 7 consecutive days. After the interventions, rats underwent behavior tests as before. Subsequently, rats were killed and specimens were collected for measurements. Immunohistochemistry was performed to examine autophagy markers such as Beclin 1 and LC3Ⅱand ELISA was used to detect SYP in the hippocampus. Results Group E after ECS significantly increased the percentage of sucrose preference (68.2%±8.7%), rearing times (7.0±1.9), total horizontal distance [(569.5±70.0) cm], es? cape latency [(21.9±5.3)s] and space exploration time [(20.5±3.9)s] compared with group D or group E before ECS. There was no significant difference in these index between groups before ECS or in group E between before and after ECS(P>0.05). Compared with group D, group E had upregulated protein expression levels of Beclin 1 and LC3Ⅱin CA1, CA3, DG as well as the area near the hippocampus and increased SYP contents (P<0.05). Conclusions Cognitive impairment in depression rats following ECS correlates with activated autophagy and increased SYP by ECS.