Radiographic Evaluation Consistency of CAD/CAM Crowns and Conventional Crowns among Different Clinicians.
Abstract: Aim & Hypothesis This study aimed to evaluate the consistency of dentists in assessing the radiographic marginal gap of crown restorations. The concordance between the crown marginal gaps under an optical microscope and evaluator judgment was assessed among different clinicians. Materials and methods In vitro, a mandibular molar was prepared to receive twelve different types of crown ... read morefollowed by radiographs and an evaluation survey. Three groups of the crowns were fabricated with different materials (Cast metal, e.max (lithium disilicate) and Zicornia) and each groups of the crowns had four different marginal gaps (75 microns, 150 microns, 225 microns and 300 microns) using an optical microscope. Twelve radiographs of each crown were taken and a radiographic evaluation survey was conducted. The scores of the clinicians' radiographic assessments were analyzed using SPSS. Data and results The median total score among all clinicians was 15.5 (scale of 0-24), with an interquartile range of 5. The median was highest in the operative faculty group (median = 18) and lowest in the dental student group (median = 14). The result of the Kruskal-Wallis test showed a significant difference between groups (p=0.003). In post-hoc Mann-Whitney U tests with Bonferroni correction, the operative faculty group and dental student group showed a significant difference (p=0.002). For the comparison of the different crown groups (cast metal crowns, e.max (lithium disilicate) crowns and zirconia crowns), the median of the e.max crown group was 6 (scale of 0-8), which was one point higher than the cast metal and zirconia groups. The result of the Friedman test showed a significant difference between groups (p<0.001). The e.max crown group showed a significant difference with the other groups (both p<0.001), whereas the difference between the cast metal and zirconia crown groups was not significant (p=0.326). For the comparison of different marginal gap groups, the median of the 150 micrometer group was 1 (scale of 0-6), which was significantly different from all the other groups which had a median of 5 (p<0.001). Conclusion The 150µm marginal gap crown group tended to exhibit false positive perceived acceptable seating on the radiographs. Clinicians tended to have greater success in classifying the marginal gaps of the e.max crown group, possibly due to the favorable radiopacity of e.max crowns. The clinical experience may affect radiographic evaluation of clinicians. The linear measurements of the marginal gaps and the radiographic evaluation of the clinicians can be different depending on the materials and the marginal gap of the evaluated crown.
Thesis (M.S.)--Tufts University, 2015.
Submitted to the Dept. of Other.
Advisor: Ali Müftü.
Committee: Nopsaran Chaimattayompol, Matthew Finkelman, and Ala Ali.
Keyword: Dentistry.read less