Marginal and internal fit of lithium disilicate endocrowns fabricated using conventional, digital, and combination techniques.

ABSTRACT

OBJECTIVE: To compare the marginal and internal adaptation of endocrowns produced using conventional technique, digital technique, and combination (cast digitization) techniques using microcomputed tomography (micro-CT). MATERIALS AND METHODS: Ten freshly extracted human mandibular molar teeth were prepared for all-ceramic endocrowns. A total of 40 Lithium Disilicate (IPS e.max) endocrowns were fabricated and grouped according to the impression and production technique to four groups Group (CO) Conventional impression/heat pressed endocrowns (n = 10), Group (CAD) Direct scanning of teeth/CAD-CAM endocrowns (n = 10), Group (COMIO) Combination; Cast digitization using Intraoral scanner/CAD-CAM endocrowns (n = 10), Group (COML) Combination; Cast digitization using laboratory scanner/CAD-CAM endocrowns (n = 10). Micro-computed tomography was used to measure the marginal and internal gaps in 11 predetermined sites. Mean marginal and internal gaps were compared using analysis of variance and Scheffe's post hoc test. RESULTS: CO, CAD, COMIO, and COML groups showed significant differences in the mean marginal gap (150 ± 35 µm, 120 ± 27 µm, 110 ± 24 µm, 120 ± 29 µm, respectively p = 0.013), gap at line angle (280 ± 70 µm, 130 ± 37 µm, 140 ± 54 µm, 130 ± 33 µm, respectively, p < 0.001), gap at cavity wall (210 ± 76 µm, 140 ± 43 µm, 140 ± 52 µm, 150 ± 44 µm, respectively, p = 0.010) and gap at pulpal floor (500 ± 150 µm, 240 ± 58 µm, 260 ± 59 µm, 240 ± 64 µm, respectively, p < 0.001). CONCLUSION: Digitally fabricated endocrowns showed superior marginal and internal fit compared to the conventionally fabricated endocrowns. CLINICAL SIGNIFICANCE: Marginal and internal adaptation are detrimental factors for the success and survival of dental restorations including endocrowns. When compared with the conventional impressions and conventional production techniques, Digital workflow is more predictable and reliable as it reduces errors and improves the accuracy of fit.