Hannover Medical School, Department of Conservative Dentistry, Periodontology and Preventive Dentistry, OE 7740, Carl-Neuberg-Straße 1, Hannover 30625, Germany.
Hannover Medical School, Department of Conservative Dentistry, Periodontology and Preventive Dentistry, OE 7740, Carl-Neuberg-Straße 1, Hannover 30625, Germany.
J Dent. 2024 Mar;142:104852. doi: 10.1016/j.jdent.2024.104852. Epub 2024 Jan 18.
The aim of this study was to compare the dentin adhesion of bulk-fill composites in high C-factor class I-cavities before and after thermocycling to a control group using incremental layering technique.
A standardized class I-cavity was prepared into 195 human molars, then different universal adhesives were applied either in self-etch or etch & rinse mode, and the cavity was filled according to each materials application protocol. The material combinations used were a conventional layered composite as control, the respective bulk-fill product, two other bulk-fill composites made by different manufacturers, with one of them being tested using two different polymerization times. Furthermore, one thermoviscous bulk-fill composite and one self-adhesive restorative were examined of which the latter can only be applied in self-etch mode. In each group the dentin adhesion to the cavity bottom was measured using microtensile bond strength test initially (24 h water storage) and after thermocycling. All results were statistically analyzed using STATA 17.0.
The statistical analysis showed significant differences between the control and the experimental groups (p < 0.001). The highest mean bond strength before (14.8 ± 10.7 MPa) and after aging (14.2 ± 11.5 MPa) was measured for the etch & rinse-control group. Among the bulk-fill groups, the etch & rinse technique consistently showed higher bond strengths. Bond strength of groups with shortened polymerization did not exceed 2.1 MPa. The bond strength of the self-adhesive restoration material was low before and after thermocycling (2.7 MPa/ 0.0 MPa). Groups with low bond strength values showed a high number of pre-testing-failures.
Bulk-fill materials used in high C-factor class I-cavities showed lower bond strength during self-etch application. The same applies for a shortened polymerization regime, which cannot be recommended for high C-factor cavities.
Today, a large variety of materials and application techniques can be used when placing an adhesive restoration. Whether new instead of established procedures should be applied in high C-factor cavities has to be critically assessed, as they are a demanding scenario for adhesive restorations.
本研究旨在比较高 C 因素 I 类洞在热循环前后使用增量分层技术的大块填充复合材料与对照组的牙本质黏附力。
将标准化的 I 类洞制备于 195 个人类磨牙中，然后分别以自酸蚀或酸蚀-冲洗模式应用不同的通用粘结剂，并根据每种材料的应用方案填充空腔。使用的材料组合为常规分层复合材料作为对照组，各自的大块填充产品，另外两种由不同制造商生产的大块填充复合材料，其中一种用两种不同的聚合时间进行测试。此外，还检查了一种热粘性大块填充复合材料和一种自粘结修复材料，其中后者只能在自酸蚀模式下应用。在每组中，使用微拉伸粘结强度试验初始（24 小时水储存）和热循环后测量空腔底部的牙本质粘结力。使用 STATA 17.0 对所有结果进行统计分析。
统计分析显示对照组和实验组之间存在显著差异（p < 0.001）。在老化前后（14.2 ± 11.5 MPa），蚀刻-冲洗对照组的平均粘结强度最高（14.8 ± 10.7 MPa）。在大块填充组中，蚀刻-冲洗技术始终显示出较高的粘结强度。缩短聚合时间的组的粘结强度不超过 2.1 MPa。自粘结修复材料的粘结强度在热循环前后均较低（2.7 MPa/0.0 MPa）。粘结强度低的组在预测试中出现大量失败。
在自酸蚀应用中，高 C 因素 I 类洞使用的大块填充材料显示出较低的粘结强度。对于缩短的聚合时间也适用，不建议用于高 C 因素的腔。
如今，在放置粘结修复体时，可以使用多种材料和应用技术。在高 C 因素的腔中是否应使用新的而不是既定的程序，必须进行批判性评估，因为它们是粘结修复的苛刻情况。
