Yoon J M, Wang Z X, Chan C K, Sun Y C, Liu Y S, Ye H Q, Zhou Y S
Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China.
Center for Digital Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2021 Feb 22;53(2):406-412. doi: 10.19723/j.issn.1671-167X.2021.02.029.
To compare the differences and indications of three evaluation methods for fitness evaluation of removable partial denture (RPD).
A RPD was fabricated and seated on the stone cast of a partially edentulous mandible, and the spaces between RPD and stone cast were recorded with polyvinyl siloxane (PVS) impression material forming PVS replicas. Using cross sectional measurement, the average thicknesses of PVS replicas were measured under stereomicroscope with different numbers of selected measuring points in the denture base, major connector, occlusal rest of the RPD, and the average thicknesses of the PVS replicas measured with different numbers of measuring points were compared using one-way analysis of variance (ANOVA) and independent sample test. Three kinds of method, including cross sectional measurement, three-dimensional analysis on the stone cast, and three-dimensional analysis on the polyether cast, were applied to measure the average thicknesses of the PVS replicas, and the average thicknesses of the PVS replicas measured by these three evaluation methods were compared with ANOVA.
For cross sectional measurement, statistically significant differences were found in the average thicknesses of the PVS replicas in the denture base and the major connector among the different numbers of measuring points ( < 0.05), but no differences were found in the average thicknesses of the PVS replicas in the occlusal rest (>0.05). There were significant differences among the average thicknesses of the PVS replicas measured by these three evaluation methods in each component of the RPD ( < 0.01). The average thickness measured by three-dimensional analysis on the stone cast and three-dimensional analysis on polyether cast were smaller than that measured by cross sectional measurement ( < 0.05). And there were no differences between the average thicknesses of PVS replicas measured by three-dimensional analysis on stone cast and three-dimensional analysis on polyether cast (>0.05).
For cross sectional measurement, the average thickness of the PVS replicas was influenced by the number of measuring points, and the measurement accuracy of cross sectional measurement was not reliable enough. Three-dimensional analysis on stone cast which is suitable for evaluation and three-dimensional analysis on polyether cast which is suitable for evaluation can evaluate the fitness of RPD more comprehensively and effectively than that of cross sectional measurement.
比较可摘局部义齿（RPD）适合性评价三种方法的差异及适应证。
制作一副RPD并戴入部分牙列缺失的下颌石膏模型上，用聚乙烯基硅氧烷（PVS）印模材料记录RPD与石膏模型之间的间隙，形成PVS复制体。采用横断面测量法，在体视显微镜下测量不同测量点数的RPD基托、大连接体、支托处PVS复制体的平均厚度，对不同测量点数所测PVS复制体的平均厚度进行单因素方差分析（ANOVA）和独立样本检验。应用横断面测量法、石膏模型三维分析法、聚醚模型三维分析法三种方法测量PVS复制体的平均厚度，对这三种评价方法所测PVS复制体的平均厚度进行ANOVA比较。
横断面测量法中，不同测量点数的RPD基托和大连接体处PVS复制体的平均厚度差异有统计学意义（P<0.05），而支托处PVS复制体的平均厚度差异无统计学意义（P>0.05）。三种评价方法所测RPD各部件PVS复制体的平均厚度差异有统计学意义（P<0.01）。石膏模型三维分析法和聚醚模型三维分析法所测平均厚度小于横断面测量法（P<0.05）。石膏模型三维分析法与聚醚模型三维分析法所测PVS复制体的平均厚度差异无统计学意义（P>0.05）。
横断面测量法中，PVS复制体的平均厚度受测量点数影响，测量准确性不够可靠。适合评价的石膏模型三维分析法和适合评价的聚醚模型三维分析法比横断面测量法能更全面、有效地评价RPD的适合性。
