Development of the three-dimensional evaluation method for alveolar ridge and denture of elderly people and its application

本研究采用触摸式测头(顶端为直径0.5 mm的球体)作为控制点，使用TriStation 600(尼康)三维坐标测量仪对牙槽骨及义齿的三维评价方法进行了研究。坐标系是使用上颌无牙颌模型(402U，Nissin)上腭部3个位置的球心(直径4 mm)来设置的。X-Y参照平面被设置为通过这三个点的平面。X轴与通过后两点的直线平行。这个坐标的原点是经过这三个点的圆的中心。参照点设在上颌全口义齿黏膜面上11个点，义齿上5个点(中切牙、左右双尖牙、左右第二磨牙)。这些点被设置为半球…直径为2 mm的凹痕更具代表性。该方法的测量精度为：X轴5.6μm，Y轴2.9μm，Z轴4.7μm。咬合面X轴为5.6μm，Y轴为3.7μm，Z轴为7.5μm。该方法的这些值足以满足三维评价方法的要求。测量时间分别为工作铸模时间、蜡义齿时间、固化后即刻、储水后1d、储存期1周。为检验不同形态老年人上颌全口义齿的尺寸精度，制作了高、中、低三种牙槽突的U型上颌无牙列模型。在这些模型上，分别采用热固化法(JIS)和微波固化法对试件进行固化，结果表明，在这两种固化方法中，各部位厚度对全口义齿固化后的变形有较大的影响。此外，与上颌高度相比，牙槽骨吸收程度对上颌全口义齿变形的影响更大。结果表明，微波固化后义齿黏膜表面的变形明显小于热固化。此外，微波固化方法中的这些变形比热固化方法中的影响小。较少

In this study, the three-dimensional coordinate measuring machine Tristation 600 (NIKON) was examined as the three dimensional evaluation method for the alveolar ridge and dentures using the touch probe (the tip is a sphere of the 0.5mm diameter) which is more useful it measures the center of the sphere as control point. The coordinate system was set using the center point in the globe division (the 4mm diameter) given for the 3 places of the palate of the maxilla edentulous model (402U, NISSIN). X-Y reference plane was set as the plane that passed through these three points. X-axis was parallel the straight line through the rear two points. The origin of this coordinate was the center of the circle that passes through these three points. The reference points were given 11 points in mucosal surface of the upper complete denture and 5 points on the artificial tooth (central incisor, primary bicuspid of right and left, second molar of right and left). These points were set as a hemispher … More ical dent of the 2mm diameter. The accuracy of this measuring method was 5.6 μ m on the X-axis, 2.9 μ m on the Y-axis, 4.7 μ m on Z-axis in the mucosal surface. On the occlusal surface, it was 5.6 μ m on the X-axis, 3.7 μ m on the Y-axis, 7.5 μ m on Z-axis. These values of this method were sufficient for the three-dimensional evaluation method. The measuring periods were the time of working cast, wax denture, just after curing, one day after the water storage, and the storage of 1 week.In order to examine the dimensional accuracy of the complete upper denture with various forms of elderly people, the maxilla edentulous ridge models with U-shape, which had high, middle and low alveolar ridge, were made. On these models, the specimens were cured by heat curing method (JIS) and microwave curing method.As a result of this study, the thickness of each part greatly influenced in the deformation after the curing of complete upper dentures in either curing method. Furthermore it was suggested the degree of the absorption of an alveolar ridge was more affective for the distortion of upper complete dentures comparing to the height of the palate. It was clear that in the microwave curing method, the distortion of mucosal surface of dentures after curing was smaller than that in the heat curing method. Furthermore these distortion in the microwave curing method was less influence than that in heat cured method. Less