Abstract
Purpose: In this study, we investigated the fitness accuracy and retentive force of retainer fabrication using laser-sintering, and the possibility of its clinical application.
Methods: Laser-sintering with a dedicated Co-Cr alloy was used to examine the following two aspects: 1) the quantity of the most suitable undercut using cantilever examination, and 2) fitness accuracy and retentive force of retainer fabrication. We used a dedicated Co-Cr alloy, gold-silver-palladium alloy and a Co-Cr alloy as casting materials. Based on observations from the first experiment, tapered specimens which had a semicircular shape in vertical cross-section were used. In experiment two, a metal prototype was produced based on the average dimensions of the mandibular first molar and samples such as retainers which had been molded by computer generated designs. Fitness accuracy was measured through embedding and cutting. Retentive force was measured using the pulling test.
Results: The quantity of the most suitable undercut using laser-sintered retainer fabrication was 0.14 mm. The result by laser-sintered retainer fabrication was at the same level as casting with regard to both fitness accuracy and retentive force.
Conclusions: Laser-sintered retainer fabrication was comparable with casting, and its clinical application may be possible.
