许宁 宋鑫 王翠妍

[摘要] 目的 探讨牙体预备中不同聚合度的沟固位形和洞固位形对增加修复体固位效果的影响。 方法 选取本院2012年1～8月的65例患者的75颗牙冠短小磨牙作为研究对象，分别进行15颗常规牙体预备修复、30颗增加沟固位形和30颗增加洞固位形全冠修复，其中沟固位形又分为两组，每组15颗，分别在近远中邻面中央制备外展度数为0°和6°的沟固位形；同样洞固位形也分为两组，每组15颗，分别在合面中央预备出外展度数为0°和6°的洞固位形，常规制作全冠，比较各组修复体的脱落情况。 结果 常规修复组脱落5颗，6°洞固位形组中脱落1颗，6°沟固位形组中脱落3颗，0°沟固位形组中脱落1颗。0°和6°洞固位形组、0°和6°沟固位形组的脱落率显著低于常规修复组，差异有统计学意义（P<0.05）。0°和6°洞固位形组的脱落率比较，差异无统计学意义（P>0.05）。0°和6°沟固位形组的脱落率比较，差异有统计学意义（P<0.05）。辅助固位形组的边缘密合度显著优于常规修复组，差异有统计学意义（P<0.05）。 结论 临床牙体预备中增加洞、沟辅助固位形，可以增加修复体的固位效果，减少修复失败率。

[关键词] 牙体预备；全冠；辅助固位形；固位效果

[中图分类号] R783 [文献标识码] A [文章编号] 1674-4721（2016）02（b）-0092-04

Influence of assist shape retention form on the increasing retention effect of restoration in the tooth preparation

XU Ning1 SONG Xin2 WANG Cui-yan1

1.Department of General Emergency，Dental Hospital of Dalian City，Dalian 116021，China；2.Department of Prosthodontics，Dental Hospital of Jinzhou District in Dalian City，Dalian 116100，China

[Abstract] Objective To explore the influence of different degree of polymerization of groove shape retention and hole shape retention on the increasing retention effect of restoration in the tooth preparation. Methods 75 dental crowns with short molars of 65 patients from January 2012 to August in our hospital were selected as the research group，15 teeth were given routine repair tooth preparation，30 teeth were given increasing the groove shape retention，30 teeth were given increasing the hole shape retention of complete coronal restoration.The groove shape retention group was divided into the two groups and 15 teeth in each group，which was respectively conducted the groove shape retention of outreach degree with 0 angle and 6 angle nearly the central of distal proximal surface.The retention hole shape was also divided into the two groups and 15 teeth in each group，which was respectively conducted the retention hole shape of outreach degree with 0 angle and 6 angle in the surface of the central.The complete crown were made in routine and loss situation of restoration was compared in the different groups. Results In the conventional repair group，there were 5 teeth off，in the 6 angle retention hole shape group，1 tooth was fell off，in the 6 angle retention groove shape group，3 teeth were fell off，in the 0 angle retention groove shape group，1 tooth was fell off.The rate of fall-off in 0 angle and 6 angle retention hole shape group，0 angle and 6 angle groove shape retention group was lower than that in the routine repair tooth preparation group，with significant difference （P<0.05）.There was no significant difference in the rate of fall-off between 0 angle and 6 angle hole shape retention group （P>0.05）.There was significant difference in the rate of fall-off between 0 angle and 6 angle groove shape retention group （P<0.05）.The marginal density of the assist shape retention group was better than that of the conventional repair group，with significant difference （P<0.05）. Conclusion Increasing hole and groove assist shape retention in clinical tooth preparation can improve the retention effect of restoration and reduce repair failure rate.

[Key words] Tooth preparation；Complete coronal；Assist shape retention form；Retention effect

修复体既要有一定的强度，不易被破损及折裂，也要有良好的固位性能，不易脱落。全冠修复后，由于牙冠短小，发生固位不良并脱落的现象时常发生，临床上可通过减小预备体相对轴面的聚合度、增大预备体的横截面直径、树脂粘结剂粘固全冠、增加辅助固位形等方法提高短小临床牙冠的修复体固位力[1]。目前，临床上常用的辅助固位形主要有洞固位形和沟固位形。为增加修复体的固位效果及辅助固位形，本研究选取本院的牙冠短小磨牙患者作为研究对象，探讨牙体预备中辅助固位形对增加修复体固位效果的影响。……