【摘要】 目的探讨桩直径对桩核冠修复体固位力的影响。方法用有机玻璃制作4组长度和聚合度相同而平均直径(D)分别为1.305mm、1.830mm、2.175mm和2.700mm的模拟牙根33个,常规铸造并粘固相应的桩核,测试桩核固位力(F)、粘接力(P)、摩擦及约束力(Q)。结果4组桩核的固位力分别为(272.13±38.07)N、(234.44±59.27)N、(273.78±54.73)N和(298.00±60.63)N,当长度与直径比值小于4.372时,桩直径与固位力、粘接力、摩擦及约束力呈线性关系,回归方程分别为F=107.98+72.08D,P=9.60+2.22D,Q=98.37+69.87D,均有统计学意义(P<0.05);大于4.372时,虽然桩直径减小,但固位力增加。结论当桩的长度直径比小于某个值(本实验为4.372)时,直径和固位力呈正相关,随着直径增大,固位力增大;而当桩的长度直径比大于某个值时,则无此规律。更多还原

【Abstract】 Objective To access the effects of post′s diameter on the retention of post_core restorations.Methods Thirty_three simulant roots with same length,taper and different diameter (1.305 mm, 1.830 mm, 2.175 mm and 2.700 mm respectively) were made of polymethylmethacrylate and were divided into 4 groups. The wax patterns of post_cores were manufactured and cast. The post_cores were cemented. After that, the adhesion, frictional force and restriction of the post_core restorations were measured.Results When the proportion of length and diameter was smaller than 4.372, the linear regression between the post′s diameter and the retention of post_core crown system was F=107.98+72.08D. The linear regression between the post′s diameter and the adhesion was P=9.60+2.22D. The linear regression between the post′s diameter and the frictional force and restriction was Q=98.37+69.87D. The statistical analysis of the results indicated significant difference (P<0.05). When the proportion of length and diameter was lager than 4.372, the retention of post_core crown system increased although the post′s diameter decreased.Conclusion When the proportion of length and diameter was smaller than 4.372, the retention of post_core crown system increased with the decrease of the post′s diameter. While the proportion was lager than a certain value, this rule did not exist.更多还原