Serious tooth defect which involved cuspid, incisal Angle, marginal ridge and occlusal surface can't be filled and need occlusal reconstruction.

各种严重的牙体缺损已涉及牙尖、切角、边缘嵴以及合面，需要咬合重建而不能使用一般充填修复者。

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An alternative rest-seat preparation, on the marginal ridge of the canine crown, conserves tooth structure and provides a rest seat of adequate length and depth to ensure support for a cast framework.

另一种休息座位的筹备工作，对边缘嵴冠的犬，保存牙齿结构和提供了充足的休息座位的长度和深度，以确保支持铸造框架。

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