Surface zone: surface zone is relatively constant and more radiopaque than the other zones.

表层：龋损区表面有一较为完整的表层，且较深层有更强放射阻射。

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Surface zone: surface zone is relatively constant and more radiopaque than the other zones.

表层：龋损区表面有一较为完整的表层，且较深层有更强放射阻射。

youdao