Department of Conservative Dentistry, King's College London Dental Institute, London SE1 9RT, UK.
Int Endod J. 2009 Dec;42(12):1071-6. doi: 10.1111/j.1365-2591.2009.01632.x.
To compare the volume of hard tooth tissue lost after caries removal, access cavity preparation, root canal preparation, fibre post space and cast post preparation in carious premolar teeth. The null hypothesis tested was that there is no difference between the volumes of hard tooth tissue lost expressed as a percentage of the preoperative hard tooth tissue volume, after each operative procedure.
Twelve extracted human premolars with mesial or distal carious cavities penetrating into the pulp chamber were selected. Teeth were scanned using a microCT scanner. After each operative procedure the loss of hard tooth tissue volume was measured. The data were statistically analysed using one-way analysis of variance and Fisher's PLSD test with statistical significance set at alpha = 0.01.
The percentage of preoperative hard tooth tissue volume lost after caries removal was 8.3 +/- 5.83, after access cavity preparation the loss of volume reached 12.7 +/- 6.7% (increase of 4.4%). After root canal preparation, fibre post space and cast post preparation the hard tissue volume lost reached, 13.7 +/- 6.7 (increase of 1%), 15.1 +/- 6.3 (increase of 1.4%) and 19.2 +/- 7.4 (increase of 4.1%) respectively. Each procedure performed after caries removal significantly increased (P < 0.01) the amount of hard tissue volume lost with the exception of the root canal preparation.
Access cavity and post space preparation are the procedures during root canal treatment which result in the largest loss of hard tooth tissue structure. Cast post space preparation causes a larger loss of tooth structure than fibre post space preparation. This should be taken into account when planning root canal treatment and restoration of root filled teeth that are to be restored with cuspal coverage restorations.
比较龋坏牙体硬组织在去龋、制备洞型、根管预备、纤维桩核预备、铸造桩核预备后丢失的体积。检验的零假设为：每种操作后，以术前牙体硬组织体积的百分比表示，丢失的牙体硬组织体积无差异。
选择 12 颗具有近中或远中龋损、穿髓腔的人离体磨牙。使用 microCT 扫描仪扫描牙齿。每种操作后测量牙体硬组织丢失的体积。采用单因素方差分析和 Fisher 的 PLSD 检验对数据进行统计学分析，显著性水平设为α=0.01。
去龋后丢失的术前牙体硬组织体积百分比为 8.3%±5.83%，制备洞型后丢失的体积达到 12.7%±6.7%（增加 4.4%）。根管预备、纤维桩核预备和铸造桩核预备后，牙体硬组织丢失体积分别达到 13.7%±6.7%（增加 1%）、15.1%±6.3%（增加 1.4%）和 19.2%±7.4%（增加 4.1%）。去龋后进行的每种操作均显著增加（P<0.01）牙体硬组织丢失量，除根管预备外。
在根管治疗过程中，制备洞型和桩核预备会导致牙体硬组织结构丢失最多。铸造桩核预备引起的牙体组织丢失大于纤维桩核预备。在计划根管治疗和用牙尖覆盖修复体修复根管填充牙时，应考虑这一点。
