Minimizing the extra-oral time in autogeneous tooth transplantation: use of computer-aided rapid prototyping (CARP) as a duplicate model tooth

OBJECTIVES: The maintenance of the healthy periodontal ligament cells of the root surface of donor tooth and intimate surface contact between the donor tooth and the recipient bone are the key factors for successful tooth transplantation. In order to achieve these purposes, a duplicated donor tooth model can be utilized to reduce the extra-oral time using the computer-aided rapid prototyping (CARP) technique. MATERIALS AND METHODS: Briefly, a three-dimensional digital imaging and communication in medicine (DICOM) image with the real dimensions of the donor tooth was obtained from a computed tomography (CT), and a life-sized resin tooth model was fabricated. Dimensional errors between real tooth, 3D CT image model and CARP model were calculated. And extra-oral time was recorded during the autotransplantation of the teeth. RESULTS: The average extra-oral time was 7 min 25 sec with the range of immediate to 25 min in cases which extra-oral root canal treatments were not performed while it was 9 min 15 sec when extra-oral root canal treatments were performed. The average radiographic distance between the root surface and the alveolar bone was 1.17 mm and 1.35 mm at mesial cervix and apex; they were 0.98 mm and 1.26 mm at the distal cervix and apex. When the dimensional errors between real tooth, 3D CT image model and CARP model were measured in cadavers, the average of absolute error was 0.291 mm between real teeth and CARP model. CONCLUSIONS: These data indicate that CARP may be of value in minimizing the extra-oral time and the gap between the donor tooth and the recipient alveolar bone in tooth transplantation.

Application of computer-added measure system in the practice training of root canal therapy / 实用口腔医学杂志

Objective:To test the validity of the computer-added measure system in pre-clinical practice training of root canal treatment with resin transparent tooth models.Methods:Two groups of students prepared resin transparent tooth models in three ways.Transparent root canal preparation was conducted by the first group, blind root canal preparation and blind followed by transparent preparation were conducted by the second group. Resin transparent tooth models were scanned frontally and laterally before and after the preparation. The computer-added measure system was used to evaluate the effect of instrumentation. The data was analyzed by SPSS 10.0 software.Results:It was helpful to understand the change of root canal shape and the problems in instrumentation by using the computer-added measure system with resin transparent tooth models in pre-clinical practice training. The transparent preparation resulted in lower frequency of the preparation defects(P