Gordan Valeria V, Mondragon Eduardo, Shen Chiayi
Department of Operative Dentistry, University of Florida, College of Dentistry, Health Science Center, PO Box 100415, Gainesville, Florida 32610, USA.
Quintessence Int. 2002 Apr;33(4):273-8.
The aim of this study was to evaluate the effect of different cavity designs, cavity depths, and shade matching on the dimensions of Class I resin-based composite preparations during replacement of the restoration.
Forty Class I cavity preparations were prepared in extracted premolars. The occlusal depths varied from 1.5 to 2.5 mm. In 20 teeth, the buccal and lingual walls were perpendicular to the pulpal floor; in another 20, they were divergent to the pulpal floor. Impressions were made of all preparations. The cavities were restored with resin-based composite. All subgroups were further divided into another two subgroups (n = 5), in which half of the teeth were restored with shade that matched the tooth and the other half were restored with a resin composite that was three shades different from the tooth. After 168 hours in distilled water, the restorations were removed. New impressions were made, and a total of 80 stone casts were fabricated. The perimeter and area of the restorations were recorded with a video-based imaging system. The dimensions of the postoperative cavity preparations were compared to the initial cavity sizes.
The depth of the original cavity preparation had a statistically significant effect on the change in cavity dimension, as measured by area and perimeter. The 2.5-mm-deep cavities showed greater loss of tooth structure. No statistically significant difference was found for different cavity designs or shade matching.
Replacement of Class I resin-based composite restorations results in loss of tooth structure. The deeper the original cavity preparation, the greater the loss of tooth structure at the occlusal cavosurface margin during replacement.
本研究旨在评估在修复体替换过程中，不同的窝洞设计、窝洞深度和颜色匹配对I类树脂基复合树脂修复体尺寸的影响。
在拔除的前磨牙上制备40个I类窝洞。咬合面深度在1.5至2.5毫米之间变化。在20颗牙齿中，颊壁和舌壁与髓室底垂直；在另外20颗牙齿中，颊壁和舌壁向髓室底发散。对所有制备的窝洞取印模。用树脂基复合材料修复窝洞。所有亚组进一步分为另外两个亚组（n = 5），其中一半牙齿用与牙齿颜色匹配的材料修复，另一半用与牙齿颜色相差三个色阶的树脂复合材料修复。在蒸馏水中放置168小时后，取出修复体。制作新的印模，共制作80个石膏模型。用基于视频的成像系统记录修复体的周长和面积。将术后窝洞制备的尺寸与初始窝洞尺寸进行比较。
通过面积和周长测量，原始窝洞制备的深度对窝洞尺寸变化有统计学显著影响。2.5毫米深的窝洞显示出更大的牙体组织损失。不同的窝洞设计或颜色匹配未发现统计学显著差异。
I类树脂基复合树脂修复体的替换会导致牙体组织损失。原始窝洞制备越深，替换过程中咬合面洞缘处的牙体组织损失越大。
