Development of precise tooth preparation technique and instruments

Objectives: Tooth preparation has been playing an important role in Prosthodontics, especially in the Esthetic Dentistry and the Perio-Prosthodontics. The horizontal and vertical marginal distance between dental prostheses and the abutment teeth affects the prognosis and the esthetics of the prostheses. The operating microscope gives higher resolution, brighter and enlarged three-dimensional images and an optimal treatment posture for dentists. In this presentation, newly developed tooth preparation burs and technique are examined. Methods: Extracted incisor teeth have prepared with 3 kinds of preparation burs, 2 kinds of preparative technique, and 3 groups of dentists (N=216). The extra fine diamond bur, the carbide bur, and a developed micro finishing bur are used. The conventional (counterclockwise rotational) tooth preparation technique and the special (pulling) tooth preparation technique have performed. Nine dentists are divided into 3 clinical experienced yearfs groups: 1 to 3 years, 4 to 6 years, and 7 to 10 years. Sixteen times magnification has used. The prostheses were manufactured by the CAD/CAM system reducing a fabricatorfs error. The profile of the prepared tooth base surface and marginal line has analyzed and observed by the scanning electron microscope and the color laser 3D profile microscope. The horizontal and vertical marginal distance between the prostheses and the abutment teeth has measured. The statistical analysis of the experimental results was accomplished with the one-way analysis of variance (ANOVA). Scheffefs F test was used for all post-hock pair wise comparison at a 99% confidence level. Results: The minimal marginal distance has obtained by the combination of micro finishing burs and pulling preparation technique. Conclusions: With the usage of the operating microscopes for precision tooth preparation, the combination of the micro finishing burs and the pulling preparation technique shows significantly better results compare to other preparation methods.