Secundar Bilal, Fathi Amirhossein, Baghaei Kimia, Atash Ramin
Researcher, School of Dentistry, Free University of Brussels (ULB), Brussels, Belgium.
Assistant Professor, Dental Prosthodontics Department, Dental Materials Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
J Prosthet Dent. 2024 Dec;132(6):1328.e1-1328.e6. doi: 10.1016/j.prosdent.2024.09.004. Epub 2024 Sep 20.
The clinical success of ceramic veneers cemented with preheated composite resin has been reported to be acceptable. Although the cementing technique requires sufficient light energy to activate its polymerization, the ability of light to penetrate through ceramic restorations of different thicknesses is unclear.
The purpose of this in vitro study was to evaluate the polymerization quality and bond joint thickness of a dual-component adhesive and a heated composite resin when bonding ceramic onlays of varying thicknesses.
Sixty noncarious maxillary premolars, extracted for orthodontic or periodontal reasons, were divided into 6 groups (n=10) and sectioned apically to the marginal ridge. Computer-aided design and computer-aided manufacturing (CAD-CAM) was used to create onlays of varying thicknesses. Following the manufacturers ' instructions, the onlays were cemented using a dual-polymerizing resin for group DP1, DP2, and DP3 groups and preheated light-polymerizing resin for groups LP1, LP2, and LP3. The numbers indicate onlay thickness in each group. Vickers testing was performed 24 hours after polymerization, with a 0.49-N static load applied for 10 seconds. Film thickness was analyzed under an optical microscope, and temperature changes were measured using a thermal imaging camera. Statistical analysis was done with the 2-factor mixed ANOVA tests (α=.05).
The Vickers hardness of a dual-polymerizing cement was lower compared with heated light-polymerizing cement (P<.05). Moreover, the thickness of the resin-ceramic restoration did not significantly affect the polymerization of a dual-polymerizing cement. However, the polymerization of the preheated light-polymerizing composite resin in group LP3 was significantly lower compared with other thicknesses (P<.05). In group LP3, the Vickers hardness of the tooth adjacent to the surface of the cement (DX2) was lower compared with indentations closer to the restoration surface (DX3, DX6), demonstrating a reduction in polymerization in the internal part. In addition, the mean film thickness of the dual-polymerizing groups (96 ±18 µm) was significantly lower than of the heated light-polymerizing groups (294 ±64 µm) (P<.05). A temperature reduction of 15 °C in the heated composite resin was also observed after 8 seconds CONCLUSIONS: The thickness of the ceramic restoration did not significantly affect the polymerization of a dual-polymerizing cement. However, the polymerization of the preheated light-polymerizing composite resin under the same ceramic restoration with a thickness of 3 mm was significantly lower. In addition, the mean film thickness for the dual-polymerizing composite resin groups was significantly lower than for the heated light-polymerizing composite resin groups.
据报道，用预热复合树脂粘结的陶瓷贴面的临床成功率是可以接受的。尽管粘结技术需要足够的光能来激活其聚合反应，但光穿透不同厚度陶瓷修复体的能力尚不清楚。
本体外研究的目的是评估在粘结不同厚度的陶瓷嵌体时，双组分粘结剂和加热复合树脂的聚合质量和粘结层厚度。
60颗因正畸或牙周原因拔除的无龋上颌前磨牙，分为6组（n = 10），并在边缘嵴根尖方向进行切片。采用计算机辅助设计和计算机辅助制造（CAD - CAM）制作不同厚度的嵌体。按照制造商的说明，DP1、DP2和DP3组使用双固化树脂粘结嵌体，LP1、LP2和LP3组使用预热光固化树脂粘结嵌体。数字表示每组嵌体的厚度。聚合24小时后进行维氏测试，施加0.49 N的静态载荷10秒。在光学显微镜下分析膜厚度，并使用热成像相机测量温度变化。采用双因素混合方差分析进行统计分析（α = 0.05）。
与加热光固化粘结剂相比，双固化粘结剂的维氏硬度较低（P < 0.05）。此外，树脂 - 陶瓷修复体的厚度对双固化粘结剂的聚合没有显著影响。然而，LP3组中预热光固化复合树脂的聚合度与其他厚度相比显著较低（P < 0.05）。在LP3组中，靠近粘结剂表面的牙齿（DX2）的维氏硬度低于靠近修复体表面的压痕（DX3、DX6），表明内部聚合度降低。此外，双固化组的平均膜厚度（96 ± 18 µm）显著低于加热光固化组（294 ± 64 µm）（P < 0.05）。8秒后还观察到加热复合树脂温度降低了15°C。
陶瓷修复体的厚度对双固化粘结剂的聚合没有显著影响。然而，在相同的3 mm厚陶瓷修复体下，预热光固化复合树脂的聚合度显著较低。此外，双固化复合树脂组的平均膜厚度显著低于加热光固化复合树脂组。
