| 0427 Quantitative Evaluation of Occlusal Reduction of Prepared Tooth | ||
|
Y. OKUYAMA1, T. ABE1, S. KASAHARA1, M. MURAMOTO2, and K. KIMURA1, 1Tohoku University, Graduate School of Dentistry, Sendai, Miyagi, Japan, 2Unisn Inc, Osaka, Japan Objectives: The objective of this study was to quantitatively evaluate occlusal reduction of prepared teeth using a non-contact measuring system. Methods: A total of 58 artificial teeth prepared by dental students for full-cast restorations were evaluated. The students prepared the maxillary left first molar in a dental cast mounted in a manikin head. One requisite regarding the preparation form was a uniform space 1.0 to 1.5 mm between the occluded teeth. The shape of the prepared tooth was measured within 100 seconds using a non-contact measuring system with a minimal resolution of 0.035 mm. The prepared tooth was computer-graphically superimposed over the non-reduced artificial tooth. Perpendicular lines were drawn from seven standard points (four cusps and three fossae) on the non-reduced artificial tooth to the prepared tooth. Distances between the foot of perpendicular and standard point were calculated automatically; one-way analysis of variance (ANOVA) was used for testing significance. Results: The average reductions (with standard deviation (SD) in parentheses) of mesiobuccal cusp, mesiolingual cusp, distobuccal cusp, and distolingual cusp were 2.71 (1.05), 1.70 (0.63), 1.67 (0.60), and 1.79 (1.19) mm, respectively. The mesiobuccal cusp showed the greatest quantity of occlusal reduction (p < 0.01). The average reduction of the four cusps was 1.97(1.01) mm. The average reductions (mm with SD) of mesial fossa, central fossa, and distal fossa were 0.86 (0.31), 0.64 (0.32), and 0.65 (0.28) mm, respectively. There were no significant differences among the three fossae (p < 0.05). The average reduction of the three fossae was 0.72(0.32) mm. Conclusion: It is concluded that occlusal reduction of prepared teeth can be evaluated quantitatively using a non-contact measuring system. The participating students tended to excessively reduce the cuspal region, whereas fossal reduction was insufficient. | ||
| Seq #69 - Fixed Prosthodontic Research, Preparations, and Impressions 10:15 AM-11:30 AM, Thursday, 11 March 2004 Hawaii Convention Center Exhibit Hall 1-2 | ||
|
Back to the Prosthodontics Research Program
| ||