Zaruba M, Kasper R, Kazama R, Wegehaupt F J, Ender A, Attin T, Mehl A
Clinic for Preventive Dentistry, Periodontology and Cariology, University of Zurich, Plattenstrasse 11, CH-8032, Zurich, Switzerland,
Clin Oral Investig. 2014;18(2):579-87. doi: 10.1007/s00784-013-0988-1. Epub 2013 May 1.
This study aims to evaluate the effect of a minimally invasive mesial-occlusal-distal (mod) preparation on the marginal adaptation of ceramic and composite inlays with the aim of saving sound dental substance.
Class II mod cavities were prepared in 50 extracted human molars and randomly allocated to five groups (n = 10). In all groups, the mesial-proximal box margins were located in the dentin, 1 mm below the cementoenamel junction (CEJ), while the distal box margins were 1 mm above the CEJ. In groups A and B, conventional standard preparations with a divergent angle of α = 6° were prepared. In groups C, D, and E, minimally invasive standard preparations with a convergent angle of α = 10° were prepared. In groups A and D, composite inlays and, in groups B and C, ceramic inlays were fabricated (chairside economical restoration of esthetic ceramics (CEREC)) and adhesively inserted. In group E, a direct composite filling using the incremental technique was placed. Replicas were taken before and after thermomechanical loading (1,200,000 cycles, 50/5 °C, max. load 49 N). Marginal integrity (tooth-luting composite, luting composite-inlay) was evaluated by scanning electron microscopy (× 200). The percentage of continuous margins in the different locations was compared between and within groups before and after cycling, using ANOVA and Scheffé post hoc test.
After the thermomechanical loading, no significant differences were observed between the different groups with respect to the interface of luting composite-inlay. At the interface of tooth-luting composite for preparations involving the dentin, groups A and B behaved significantly better compared to the control group E, which in turn were not different to groups C and D.
Composite and ceramic inlays inserted in minimally invasive prepared mod cavities result in margins not different from those of inlays placed in conventional mod preparations. Direct composite filling margins, however, were inferior to those attained by conventional indirect restorations.
Minimally invasive preparations for mod inlays with undercuts show marginal adaptation equal to that of conventional inlay preparation design.
本研究旨在评估微创近中-咬合面-远中（MOD）预备对陶瓷和复合树脂嵌体边缘适合性的影响，以期保留健康牙体组织。
在50颗拔除的人磨牙上制备Ⅱ类MOD洞型，并随机分为五组（n = 10）。所有组中，近中邻面盒状边缘位于牙本质内，在釉牙骨质界（CEJ）下方1 mm处，而远中盒状边缘在CEJ上方1 mm处。A组和B组制备具有α = 6°发散角的传统标准预备体。C组、D组和E组制备具有α = 10°会聚角的微创标准预备体。A组和D组制作复合树脂嵌体，B组和C组制作陶瓷嵌体（椅旁美学陶瓷修复体（CEREC））并粘结就位。E组采用分层技术进行直接复合树脂充填。在热机械加载（1,200,000次循环，50/5°C，最大载荷49 N）前后制作复制体。通过扫描电子显微镜（×200）评估边缘完整性（牙齿-粘结性复合树脂、粘结性复合树脂-嵌体）。使用方差分析和Scheffé事后检验比较循环前后组间和组内不同位置连续边缘的百分比。
热机械加载后，在粘结性复合树脂-嵌体界面方面，不同组之间未观察到显著差异。在涉及牙本质的预备体的牙齿-粘结性复合树脂界面，A组和B组的表现明显优于对照组E，而E组与C组和D组没有差异。
在微创预备的MOD洞中插入的复合树脂和陶瓷嵌体，其边缘与传统MOD预备体中放置的嵌体边缘无差异。然而，直接复合树脂充填的边缘不如传统间接修复体的边缘。
有倒凹的MOD嵌体的微创预备显示出与传统嵌体预备设计相同的边缘适合性。
