大 MOD 修复体的优化：复合树脂嵌体与短纤维增强型直接修复体。

Optimization of large MOD restorations: Composite resin inlays vs. short fiber-reinforced direct restorations.

机构信息

Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, USC, 925 W 34th St, Los Angeles, CA 90089, USA.

出版信息

Dent Mater. 2018 Apr;34(4):587-597. doi: 10.1016/j.dental.2018.01.004. Epub 2018 Jan 20.

DOI:10.1016/j.dental.2018.01.004

PMID:29366492

Abstract

OBJECTIVE

To compare mechanical performance and enamel-crack propensity of direct, semi-direct, and CAD/CAM approaches for large MOD composite-resin restorations.

METHODS

45 extracted maxillary molars underwent standardized slot-type preparation (5-mm depth and bucco-palatal width) including immediate dentin sealing (Optibond FL) for the inlays (30 teeth). Short-fiber reinforced composite-resin (EverX Posterior covered by Gradia Direct Posterior) was used for the direct approach, Gradia Direct Posterior for the semi-direct, and Cerasmart composite resin blocks for CAD/CAM inlays. All inlays were adhesively luted with light-curing composite-resin (preheated Gradia Direct Posterior). Shrinkage-induced enamel cracks were tracked by transillumination photography. Cyclic axial isometric chewing (5-Hz) was simulated, starting with a load of 200N (5000 cycles), followed by stages of 400, 600, 800, 1000, 1200, and 1400N (maximum 30,000 cycles each) until fracture or to a maximum of 185,000 cycles. Survived specimens were subjected to cyclic-load-to-failure test at 30-degree angle on the palatal cusp.

RESULTS

Only small shrinkage-induced cracks were found in 47% of the direct restorations compared to 7% and 13% of semi-direct and CAD/CAM inlays, respectively. Survival to accelerated fatigue was similar for all three groups (Kaplan-Meier p>.05) and ranged between 87% (direct) and 93% (semi-direct and CAD/CAM). Cyclic-load-to-failure tests did not yield significant differences either (Life Table analysis, p>.05) with median values of 1675N for CAD/CAM inlays, 1775N for fiber-reinforced direct restorations and 1900N for semi-direct inlays.

SIGNIFICANCE

All three restorative techniques yielded excellent mechanical performance above physiological masticatory loads. Direct restorations performed as good as inlays when a short-fiber reinforced composite-resin base was used.

摘要

目的

比较直接法、半直接法和 CAD/CAM 法修复大 MOL 复合树脂嵌体的机械性能和釉质裂纹倾向。

方法

45 颗上颌磨牙进行标准化槽型制备（5mm 深度和颊腭向宽度），包括即刻牙本质封闭（Optibond FL）用于嵌体（30 颗牙）。短纤维增强复合树脂（EverX Posterior 覆盖 Gradia Direct Posterior）用于直接法，Gradia Direct Posterior 用于半直接法，Cerasmart 复合树脂块用于 CAD/CAM 嵌体。所有嵌体均采用光固化复合树脂（预热 Gradia Direct Posterior）进行胶结。通过透照摄影跟踪收缩引起的釉质裂纹。模拟循环轴向等距咀嚼（5Hz），首先施加 200N 的载荷（5000 次循环），然后进行 400、600、800、1000、1200 和 1400N 的阶段（每个阶段最大 30000 次循环），直到断裂或达到最大 185000 次循环。存活的标本在腭尖上以 30 度角进行循环载荷至失效试验。

结果

与半直接和 CAD/CAM 嵌体分别为 7%和 13%相比，只有 47%的直接修复体发现较小的收缩诱导裂纹。所有三组的加速疲劳存活率相似（Kaplan-Meier p>.05），范围在 87%（直接）和 93%（半直接和 CAD/CAM）之间。循环载荷至失效试验也没有显著差异（寿命表分析，p>.05），CAD/CAM 嵌体的中位数为 1675N，纤维增强直接修复体为 1775N，半直接嵌体为 1900N。