下颌单侧球帽附着体覆盖义齿再就位的研究

Clinical study of base adaptation of unilateral ball attachment overdentures before and after in place again

目的：通过比较球帽附着体覆盖义齿再就位前后适合性的变化，评价其再就位的效果。方法选择戴用30-36个月的下颌单侧球帽覆盖义齿4例，利用硅橡胶法分别制取附着体再就位前后规定咬合状态下的义齿组织面的适合性记录，利用透光法拍摄记录的图像，在Photoshop软件中确定硅橡胶膜的灰度，结合硅橡胶膜片厚度与透光性的关系计算出适合性记录的实际厚度，再计算出硅橡胶膜厚度的变化来反映义齿再就位前后基托适合性的变化，评价附着体再就位的效果。结果义齿再就位后下颌各测量位点适合性数值均较附着体再就位前明显减小50%以上，前牙区及有球帽侧磨牙区差值是无球帽侧磨牙区差值的2倍多，上颌前牙区和有球帽侧对应的上颌磨牙区数值较再就位前增大。与戴用3个月的下颌单侧球帽覆盖义齿比较，再就位前覆盖义齿适合性记录厚度是戴用3个月的义齿适合性记录厚度的2~4倍，再就位后与戴用3个月的义齿各位点适合性记录厚度相近，差值很小。结论附着体再就位能够显著改善下颌义齿的适合性，明显减小或消除基牙支点效应，并对上颌义齿功能状态下的固位和稳定有积极影响。

Objective To compare the adaptation of ball attachment overdentures before and after in place again and to evaluate the effect. Methods Four cases of unilateral ball attachment overdentures after 30-36 months of service were included. The adaptation record of the foundation surface of overdenture under the provisions of occlusal state was obtained and photographed with silicone rubber and before and after in place again. The grayscale difference in Photoshop CS was measured and the actual thickness of adaptation record calculated by combining the thickness with the translucency of adaptation record. The results of the attachment in place again was evaluated. Results The values of adaptation record in all measurements of the mandible after in place again were 50% less than before in place. The values of adaptation record in maxillary anterior and molar region were all increased. The value of adaptation record before in place again was twice as much as the unilateral attachment overdentures in service for 3 months, and the value of adaptation record after in place again was similar. Conclusion The attachment in place again could significantly improve the adaptation of mandibular overdentures, reduce or eliminate the effect of abutment fulcrum and benefit the retention and stability of the maxillary complete dentures.