Methods To incubate the caries free permanent teeth with acid gelatinoid and/or collagenase, then to observe the ultrastructural change of root surface under scanning electron microscope .

• 方法将无龋恒牙分组经酸性胶液和胶原酶分别或共同孵化处理后切割制样,脱水干燥,喷金,扫描电镜观察根面超微结构的变化。