To evaluate the marginal discrepency and internal fit of dmls copings fabricated using 3 different dmls machines

Abstract

10 newline ABSTRACT newlineStatement of the problem: Metal-ceramic restorations are frequently made newlineusing laser sintering. Also the sintering process and material layer thickness newlinemay have an impact on restoration adaptation. However, there is little newlineinformation about its impact. newlinePurpose of the study: The goal of this in vitro experiment was to compare newlinethe marginal and internal adaptation of laser-sintered cobalt-chromium long newlinespan bridges and single crown frameworks made on different DMLS newlinemachines. newlineMaterials and methods: Tooth preparation was carried out on a typhodont newlineteeth set from 14-22 and for 16. The dies were scanned and the samples were newlinedesigned using 3 Shape software. The samples were then laser sintered using newline3 different DMLS machines. Sample size consisted of 6 samples for the long newlinespan framework and 6 samples for the single crown framework per machine. newlineMarginal accuracy was evaluated at 6 different points (mesiobuccal, buccal, newlinedistobuccal, mesiopalatal, palatal and distoplatal surface). Light body newlineimpressions were recorded for all the single crown prosthesis. The impression newlinewas then sectioned into 3 transverse slices (coronal, middle and cervical). newlineInternal thickness was evaluated at 4 different points on each slice of the light newlinebody impression. The microscopic evaluation was carried out using a newlinestereomicroscope. The discrepancy and internal fit values were recorded and newlinetabulated. Spss version 20 software was used to carry out statistical analysis. newlineDescriptive ANOVA test followed by Benferroni test was used to evaluate the newlinestatistical significance. newlineRESULTS: The EOS machine (0.0763 and#22303; 0.0602m) followed by Shining 3D newlinemachine (0.1148 and#22303; 0.923) showed the lowest overall marginal discrepancy newlinevalues, whereas the OR laser (0.1449 and#22303; 0.0687) machine showed the highest newlinemarginal discrepancy values. There was a significant difference in the overall newline11 newlinemarginal discrepancy values after applying ANOVA test (P value 0.00). The newlineproximal surfaces showed higher discrepancy levels as compared to the other.