Oper Dent. 2020 Sep 1;45(5):496-505. doi: 10.2341/19-101-L.
Shortened light curing does not affect volumetric polymerization shrinkage or cohesive tensile strength but negatively affects the shear bond strength of some bulk-fill resin composites. When performing shortened light curing, clinicians should be aware of the light output of their light-curing units.
Purpose: To evaluate volumetric polymerization shrinkage (VPS), shear bond strength (SBS) to dentin, and cohesive tensile strength (CTS) of bulk-fill resin composites (BFRCs) light activated by different modes.Methods and Materials: Six groups were evaluated: Tetric EvoCeram bulk fill + high mode (10 seconds; TEC H10), Tetric EvoFlow bulk fill + high mode (TEF H10), experimental bulk fill + high mode (TEE H10), Tetric EvoCeram bulk fill + turbo mode (five seconds; TEC T5), Tetric EvoFlow bulk fill + turbo mode (TEF T5), and experimental bulk fill + turbo mode (TEE T5). Bluephase Style 20i and Adhese Universal Vivapen were used for all groups. All BFRC samples were built up on human molar bur-prepared occlusal cavities. VPS% and location were evaluated through micro-computed tomography. SBS and CTS tests were performed 24 hours after storage or after 5000 thermal cycles; fracture mode was analyzed for SBS.Results: Both TEC H10 and TEE H10 presented lower VPS% than TEF H10. However, no significant differences were observed with the turbo-curing mode. No differences were observed for the same BFRC within curing modes. Occlusal shrinkage was mostly observed. Regarding SBS, thermal cycling (TC) affected all groups. Without TC, all groups showed higher SBS values for high mode than turbo mode, while with TC, only TEC showed decreased SBS from high mode to turbo modes; modes of fracture were predominantly adhesive. For CTS, TC affected all groups except TEE H10. In general, no differences were observed between groups when comparing the curing modes.Conclusions: Increased light output with a shortened curing time did not jeopardize the VPS and SBS properties of the BFRCs, although a decreased SBS was observed in some groups. TEE generally showed similar or improved values for the tested properties in a shortened light-curing time. The VPS was mostly affected by the materials tested, whereas the SBS was affected by the materials, curing modes, and TC. The CTS was not affected by the curing modes.
缩短光固化时间不会影响体积聚合收缩或内聚拉伸强度，但会降低某些块状填充树脂复合材料的抗剪粘结强度。当进行缩短光固化时，临床医生应注意其光固化器的光输出。
目的：评估不同模式激活的块状填充树脂复合材料（BFRC）的体积聚合收缩（VPS）、牙本质抗剪粘结强度（SBS）和内聚拉伸强度（CTS）。
评估了 6 组：Tetric EvoCeram 块状填充+高模式（10 秒；TEC H10）、Tetric EvoFlow 块状填充+高模式（TEF H10）、实验性块状填充+高模式（TEE H10）、Tetric EvoCeram 块状填充+涡轮模式（5 秒；TEC T5）、Tetric EvoFlow 块状填充+涡轮模式（TEF T5）和实验性块状填充+涡轮模式（TEE T5）。所有组均使用 Bluephase Style 20i 和 Adhese Universal Vivapen。所有 BFRC 样本均在人磨牙预备的颌面窝洞内构建。通过微计算机断层扫描评估 VPS%和位置。24 小时储存后或 5000 次热循环后进行 SBS 和 CTS 测试；SBS 测试分析断裂模式。
TEC H10 和 TEE H10 的 VPS%均低于 TEF H10，但涡轮固化模式无显著差异。同一 BFRC 之间，固化模式无差异。观察到主要为牙合面收缩。SBS 方面，热循环（TC）影响所有组。无 TC 时，高模式下所有组的 SBS 值均高于涡轮模式，而有 TC 时，只有 TEC 显示高模式到涡轮模式 SBS 降低；断裂模式主要为黏附性。对于 CTS，TC 除 TEE H10 外，影响所有组。一般来说，比较固化模式时，各组间无差异。
增加光输出并缩短固化时间不会危及 BFRC 的 VPS 和 SBS 性能，尽管一些组的 SBS 降低。在缩短的光固化时间内，TEE 通常对测试性能表现出相似或更好的数值。VPS 主要受测试材料影响，而 SBS 受材料、固化模式和 TC 影响。固化模式不影响 CTS。
