Ozcan Mutlu, van der Sleen Jeroen M, Kurunmäki Hemmo, Vallittu Pekka K
Faculty of Medical Sciences, Department of Dentistry and Dental Hygiene, University of Groningen, Groningen, The Netherlands.
J Prosthodont. 2006 Sep-Oct;15(5):283-8. doi: 10.1111/j.1532-849X.2006.00124.x.
The objective of this study was to evaluate the effect of four repair methods on the fracture load of repaired ceramic-fused-to-metal crowns.
Metal-ceramic crowns were fractured, and the failure load was measured. The fractured metal-ceramic crowns (n = 9) were assigned randomly to the following treatment groups: (1) hydrofluoric acid (9.5%) etching, (2) air-particle abrasion (50 microm Al(2)O(3)), (3) silica coating (30 microm SiO(x)), and (4) the application of a layer of glass fiber-reinforced composite (FRC) (thickness: 0.12 mm) on the repair surface. The crowns were repaired with a highly filled resin composite and subjected to 3 repair cycles (n = 27). All specimens were stored in water at 37 degrees C for 24 hours and then thermocycled (6000 cycles, 5 degrees C to 55 degrees C). The fracture load values for final failure of intact and repaired crowns were measured with a universal testing machine, and failure types were recorded.
No significant differences (p > 0.05) were found between the final failure values for the groups treated with 9.5% hydrofluoric acid (376 N) and airborne particle abrasion with either Al(2)O(3) (432 N) or SiO(x) (582 N) followed by silanization, respectively. Significantly, higher (p < 0.0001) final failure values (885 N) were obtained with the use of the FRC layer when compared with the other repaired groups. There was no significant difference (p > 0.05) between the final fracture load of intact crowns (872 N) and those repaired with FRC (885 N) (One-way ANOVA with repeated measures, Bonferroni test). No significant difference in fracture loads was found between the 1st, 2nd, and 3rd repair cycles (558 N, 433 N, 485 N, respectively). Failure sites were predominantly at the alloy/veneering resin interface in Group 1; Groups 2 and 3 both showed more cohesive failures than Group 1. In the case of FRC, the failure pattern was exclusively cohesive between the two laminates of FRC layer.
The conditioning methods (Groups 1 to 3) of the repair surfaces did not show differences between each other; each resulted in mean fracture loads at lower levels than that of the intact crowns. Addition of an FRC layer increased the fracture load to the level of intact crowns. This suggests that the use of FRC in repairs of metal-ceramic crowns might be a viable option.
本研究的目的是评估四种修复方法对烤瓷熔附金属全冠修复体断裂载荷的影响。
将金属烤瓷冠折断并测量其破坏载荷。将折断的金属烤瓷冠（n = 9）随机分为以下治疗组：（1）氢氟酸（9.5%）蚀刻，（2）气粒喷砂（50μm Al₂O₃），（3）二氧化硅涂层（30μm SiOₓ），（4）在修复表面涂覆一层玻璃纤维增强复合材料（FRC）（厚度：0.12mm）。用高填料树脂复合材料修复全冠，并进行3个修复周期（n = 27）。所有标本在37℃水中储存24小时，然后进行热循环（6000次循环，5℃至55℃）。用万能试验机测量完整和修复后全冠最终破坏时的断裂载荷值，并记录破坏类型。
用9.5%氢氟酸处理组（376N）、用Al₂O₃（432N）或SiOₓ（582N）气粒喷砂后再硅烷化处理组的最终破坏值之间无显著差异（p > 0.05）。与其他修复组相比，使用FRC层时获得的最终破坏值显著更高（p < 0.0001）（885N）。完整全冠（872N）与用FRC修复的全冠（885N）的最终断裂载荷之间无显著差异（p > 0.05）（重复测量的单因素方差分析，Bonferroni检验）。在第1、2和3个修复周期之间，断裂载荷无显著差异（分别为558N、433N、485N）。第1组的破坏部位主要在合金/饰面树脂界面；第2组和第3组的内聚破坏均多于第1组。对于FRC，破坏模式仅发生在FRC层的两个层板之间的内聚破坏。
修复表面的预处理方法（第1至3组）之间未显示出差异；每种方法导致的平均断裂载荷均低于完整全冠。添加FRC层可将断裂载荷提高到完整全冠的水平。这表明在金属烤瓷冠修复中使用FRC可能是一种可行的选择。
