一体化玻璃纤维桩修复漏斗状根管粘接强度的体外研究

目的: 比较3种纤维桩(CAD/CAM一体化玻璃纤维桩、预成型玻璃纤维桩、光固化可塑性纤维桩)对漏斗状根管的粘接强度及温度循环对其粘接强度的影响。方法: 90颗单根离体牙随机分为3组,分别采用CAD/CAM一体化玻璃纤维桩核、同种材料制成的预成型玻璃纤维桩、光固化可塑性纤维桩修复,粘结完成后,储存在37 ℃恒温去离子水中7 d,每组随机选取15颗离体牙进行温度循环。使用精密片切机制备微推出试验试件,万能力学试验机测试微推出粘接强度并使用体视显微镜分析破坏形式。结果: CAD/CAM一体化玻璃纤维桩核组:温度循环前根颈部、根中部、根尖部的粘接强度分别为(9.58±2.67) MPa、(8.62±2.62) MPa、(8.21±2.48) MPa,温度循环后根颈部、根中部、根尖部的粘接强度分别为(8.14±3.19) MPa、(6.43±2.47) MPa、(6.45±3.20) MPa;预成型纤维桩组:温度循环前根颈部、根中部、根尖部的粘接强度分别为(3.89±2.04) MPa、(4.83±1.23) MPa、(4.67±1.86) MPa,温度循环后根颈部、根中部、根尖部的粘接强度分别为(6.18±1.61) MPa、(5.15±1.94) MPa、(6.39±2.87) MPa;光固化可塑性纤维桩组:温度循环前根颈部、根中部、根尖部的粘接强度分别为(4.05±2.41) MPa、(1.75±1.70) MPa、(2.60±2.34) MPa,温度循环后根颈部、根中部、根尖部的粘接强度分别为(5.04±2.72) MPa、(1.96±1.70) MPa、(1.34±0.92) MPa。桩核类型、根管部位对粘接强度的影响具有统计学意义(P<0.05),与其他两组相比,一体化玻璃纤维桩核在根颈部、根中部、根尖部均具有最高的粘接强度。温度循环对3种纤维桩粘接强度的影响无统计学意义(P>0.05)。结论: 一体化玻璃纤维桩核可能具有更好的粘接强度,粘接性能较好。

Study of bond strength of one-piece glass fiber posts-and-cores with flared root canals in vitro

Objective: To compare the effects of three kinds of fiber posts (CAD/CAM one-piece glass fiber posts-and-cores, prefabricated glass fiber post and light curing plastic fiber post) on the bond strength of flared root canals and the effect of thermal cycling on their bond strength.Methods: Extracted human single teeth (n=90) were endodontically treated and randomly divided into three groups (n = 30 each). The teeth were restored by three kinds of fiber post: CAD/CAM one-piece glass fiber posts-and-cores, prefabricated posts and light curing plastic fiber post. Following post cementation, the specimens were stored in distilled water at 37 ℃ for 7 days. Half bonded specimens of each group were submitted to thermal cycling (6 000 times, 5 to 55 ℃) prior to micro-push-out bond strength test. Fabrication of micro-push-out bond strength test specimens was conducted by precision slicing machine. The micro-push-out bond strength was tested using a universal testing machine, and the failure modes were examined with a stereomicroscope.Results: In CAD/CAM one-piece glass fiber posts-and-cores group, the bond strength of cervical, middle and apical was (9.58±2.67) MPa,(8.62±2.62) MPa,(8.21±2.48) MPa respectively before thermal cycling, and after thermal cycling the bond strength of cervical, middle and apical was (8.14±3.19) MPa,(6.43±2.47) MPa,(6.45±3.20) MPa respectively. In prefabricated posts group, the bonding strength of cervical, middle and apical was (3.89±2.04) MPa,(4.83±1.23) MPa,(4.67±1.86) MPa respectively before thermal cycling, and after thermal cycling the bond strength of cervical, middle and apical was (6.18±1.61) MPa,(5.15±1.94) MPa,(6.39±2.87) MPa respectively. In light curing plastic fiber post group, the bond strength of cervical, middle and apical before thermal cycling was (4.05±2.41) MPa,(1.75±1.70) MPa,(2.60±2.34) MPa respectively, and after thermal cycling the bond strength of cervical, middle and apical was (5.04±2.72) MPa,(1.96±1.70) MPa,(1.34±0.92) MPa respectively. Postal types and root canal regions were found to significantly affect the push-out bond strength. Compared with the other two groups, the one-piece glass fiber posts-and-cores had the highest bonding strength in the cervical, middle and apical. Temperature cycling has no significant effect on the micro push-out bond strength of three kinds of fiber posts.Conclusion: One-piece glass fiber posts-and-cores has better bonding strength and excellent bonding performance.