Camacho Guilherme Brião, Gonçalves Mariane, Nonaka Tomio, Osório Angela Brys
Department of Dental Prosthesis Unit III, Pelotas Federal University, Pelotas, Rio Grande do Sul, Brazil.
Am J Dent. 2007 Apr;20(2):121-4.
To evaluate the fracture resistance (axial compressive strength) of premolars restored with different dental materials under two axial loads.
Fracture strength was performed using two metal spheres with 3 mm and 9 mm diameter. Five restorative techniques were chosen for MOD cavity preparations (n = 10): (1) direct resin composite restorations (Z-250); (2) indirect resin composite restorations (Z-250 and RelyX); (3) ceramic inlays (Vitadur Alpha); (4) conventional amalgam restorations (GS-80); (5) bonded amalgam restorations. The restored teeth were compared to human caries-free premolars (Group 6/control). Enforce resin cement was used for ceramic and amalgam adhesive restorative techniques, according to the manufacturers' instructions. Whenever required, the teeth were conditioned by the total etch technique.
The ANOVA analysis pointed out a significant difference among the groups (P < 0.01) and the "site" factor (P < 0.1). The ceramic restorations presented the highest values for fracture strength and were similar to the control group. The statistical results of direct and indirect resin composite restorations were similar but inferior to the control group. The amalgam restorations (conventional and bonded) presented the lowest values, with no difference between them. All amalgam groups displayed lower strengths when the load was applied on the central fossa (3 mm 0 sphere) compared to load applied on cusps (9 mm 0 sphere).
评估在两种轴向载荷下，用不同牙科材料修复的前磨牙的抗折性（轴向抗压强度）。
使用直径为3毫米和9毫米的两个金属球进行抗折强度测试。选择五种修复技术用于制备MOD洞型（n = 10）：（1）直接树脂复合材料修复（Z - 250）；（2）间接树脂复合材料修复（Z - 250和RelyX）；（3）陶瓷嵌体（Vitadur Alpha）；（4）传统汞合金修复（GS - 80）；（5）粘结汞合金修复。将修复后的牙齿与无龋的人类前磨牙（第6组/对照组）进行比较。根据制造商的说明，对陶瓷和汞合金粘结修复技术使用强化树脂粘结剂。如有需要，采用全酸蚀技术对牙齿进行预处理。
方差分析指出各组之间存在显著差异（P < 0.01）以及“部位”因素存在显著差异（P < 0.1）。陶瓷修复体的抗折强度值最高，且与对照组相似。直接和间接树脂复合材料修复体的统计结果相似，但低于对照组。汞合金修复体（传统和粘结）的值最低，两者之间无差异。与施加在牙尖上的载荷（9毫米球体）相比，当载荷施加在中央窝（3毫米球体）上时，所有汞合金组的强度都较低。
