Abstract

FLORES VALVERDE, Yovana Elisa et al. Adaptation of metallic copings made with two techniques: loss wax cast conventional centrifugation and selective laser melting. Rev. Estomatol. Herediana [online]. 2017, vol.27, n.2, pp.88-100. ISSN 1019-4355.  http://dx.doi.org/https://doi.org/10.20453/reh.v27i2.3139.

A good marginal adaptation decreases the probability of caries, periodontal disease and failure of there storation. The internal adaptation is the adjustment between the preparation surface and the internal surface of the restoration, providing retention. The most commonly used metal alloy is nickel-chromium (Ni-Cr); how ever it has limitations such as allergic reactions. The cobalt-chromium alloy (Co-Cr) is an alternative to have biocompatibility, mechanical strength, corrosion resistance and acceptable cost. The new digitized technologies havea llowed to migrate from the technique of wax loss cast by centrifugation (CPC) to the manufacture of subtraction or additive manufacturing, such as selective laser melting (SLM). Objectives: To compare the marginal and internal discrepancies of Cobalt-Chromium alloy copings units (Co-Cr) on a chamfer termination line, made with two techniques: CPC and SLM, determining which technique had better marginal and internal adaptation. Material and Methods: 13 Co-Cr alloy unit copings were fabricated for each technique to be evaluated. Silicon replication was used to evaluate the marginal and internal discrepancies. Each sample was cross-sectioned in the vestibular-palatine and mesio-distal directions, then the cervical, axial and occlusal zones were evaluated with a stereomicroscope. Results: The normality assumptions were evaluated with the Shapiro-Wilk test. Statistical analyzes were Student’s t test and U Mann-Whitney test. The SLM had a smaller marginal discrepancy compared to CPC, with statistically significant differences (p <0.05) between both techniques. On the other hand, when comparing the internal discrepancy, no statistical differences were found. Conclusions: The best marginal adaptation was for metal fittings of SLM. As for the internal adaptation, the descriptive values were not conclusive to decide which technique was best.

Keywords : Computer-Aided Design; Adaptation; Lasers Solid-State.