正圆形圆洞标记法测量口腔不规则藻酸盐印模形变的实验研究

Application of round-shape pin-hole marker measurement in irregular alginate dental impression deformation

目的探讨添加正圆形圆洞标记点测量口腔不规则藻酸盐印模形变的可行性。方法模拟临床固定修复基牙牙备体制作金属母模,表面有互成三角形的凸出圆形钢针,分别用两种藻酸盐印模材料(Alginoplast和Palgat Plus)制取印模样本各10个,钢针对应部位形成圆洞标记。脱模后运用体式显微镜观察标记点边缘情况,以正圆心模拟软件标定坐标,测量脱模后0、2、4、6、8、10、12、15、20 min时间点的标记点位移值(测量CG长径线段变化时增加30 min时间点),计算印模样本的线性变化率。结果脱模后的圆洞标记点边缘轮廓清晰,圆心坐标重复性好。在脱模后20 min时间点,Alginoplast印模样本的线性变化率为0.38%,Palgat Plus印模样本的线性变化率为0.45%。Alginoplast印模样本在脱模后2 min时间点的标记点位移增大0.040%(8.4μm),最大减小值为30 min时的0.237%(49.4μm);Palgat Plus印模样本在脱模后2 min时间点的标记点位移增大0.068%(14.2μm),最大减小值为30 min时的0.189%(39.5μm)。结论采用正圆形圆洞标记法对口腔不规则藻酸盐印模形变情况进行检测是可行的。

Objective To investigate the feasibility of round-shape pin-hole marker measurement of irregular alginate dental impression deformation.Methods The metal model simulating abutment preparations was obtained,which had triangle-formed circular needles on the surface.Two types of alginate impression（Alginoplast and Palgat Plus,n=10 for each material） made by the metal model had the corresponding pin-hole markers.The dimensional changes of the markers after model withdrawl were observed by stereomicroscopy.The data of coordinates 0 min,2 min,4 min,6 min,8 min,10 min,12 min,15 min and 20 min after model withdrawl were output by the software which could simulate the center of a circle to measure the displacement and impression accuracy（additional time point of 30 min after model withdrawl for CG length recording）,and the linear dimensional change rates of impression samples were calculated.Results The outline of the pin-hole marker was clear,and the values of center coordinates were well repeated.The linear dimensional change rate of Alginoplast impression samples was 0.38% 20 min after model withdrawl,and that was 0.45% for Palgat Plus impression samples.For Alginoplast impression samples,the coordinate increased by 0.040%（8.4 μm） 2 min after model withdrawl,and decreased by 0.237%（49.4 μm） 30 min after model withdrawl.For Palgat Plus impression samples,the coordinate increased by 0.068%（14.2 μm） 2 min after model withdrawl,and decreased by 0.189%（39.5 μm） 30 min after model withdrawl.Conclusion The round-shape pin-hole marker measurement of irregular alginate dental impression deformation is feasible.