The effect of scanning device, spacer setting, and cementing on the marginal and internal fit of CADCAM milled all-ceramic full contour crowns
Date
2011
DOI
Authors
Wu, George Ding-Chun
Version
OA Version
Citation
Abstract
Purpose: The purpose of this study was to evaluate the effect of cement, spacer setting, and three scanners on the marginal gap and internal fit of Sirona CAD/CAM all-ceramic full contour crowns.
Materials and Methods: Prepared Ivorine typodont teeth were duplicated using poly-vinyl siloxane and poured with Type IV scannable dental stone. Four groups of twelve dies were divided into: inLab laser scanned dies with crowns milled at a 30 [mu]m spacer setting (in CEREC 3D), InEos red scanned dies with crowns milled at a 30 [mu]m spacer setting, Bluecam scanned dies with crowns milled at a 30 [mu]m spacer setting, and Bluecam scanned dies with crowns milled at a 80 [mu]m spacer setting. All-ceramic crowns were fabricated by a CEREC inLab milling unit using VITA Mark II blocks. Crowns needing adjustments for complete seating to their respective dies were recorded. After adjustments the marginal gap of the milled crowns to their respective dies were measured using an optical microscope. The crowns were then cemented on the dies using resin cement (3M Rely-X Unicem), set into epoxy resin, and sectioned. The marginal gap and internal fit after cementation were measured using an optical microscope.
Results: Measurements for the CEREC inLab (30 [mu]m spacer setting) mean marginal gaps after adjustments were 58.00[mu]m±33 .13[mu]m, cemented crowns' marginal gaps 102.13[mu]m±44.64[mu]m, and cemented crowns' internal fit 169.16[mu]m±91.95[mu]m. Measurements for the CEREC Bluecam (30 [mu]m spacer) mean marginal gaps after adjustments were 26.6 l [mu]m±l 4.25[mu]m, cemented crowns' marginal gaps 79.58[mu]m±24 .98[mu]m, and cemented crowns' internal fit 126.26[mu]m±83.10[mu]m. Measurements for the CEREC inEos red (30 [mu]m spacer) mean marginal gaps after adjustments were 28.83[mu]m±l 5.29[mu]m, cemented crowns' marginal gaps l 18.20[mu]m±43.08[mu]m, and cemented crowns ' internal fit 138.49[mu]m±80.14[mu]m. Measurements for the CEREC Bluecam (80 [mu]m spacer) mean marginal gaps after adjustments were 3l. l 7[mu]m±l 1.79[mu]m, cemented crowns' marginal gaps 45.78[mu]m±l5.60[mu]m, and cemented crowns' internal fit 165.72[mu]m±73.58[mu]m. 8 of 12 crowns for the three scanner groups using a 30 [mu]m spacer setting needed adjustments. None of the crowns from the Bluecam (80 [mu]m spacer) group needed adjustments.
Conclusion: CEREC CAD/CAM crowns fabricated with a 30 [mu]m spacer setting needed adjustments (8 out of 12 crowns). Crowns fabricated with an 80 [mu]m spacer setting did not need any adjustments. ANOVA and Tukey test revealed that before cementation, full contour all-ceramic crowns milled using a 30 [mu]m spacer setting (in CEREC 3D) and generated by scanning dies with the inLab had marginal gaps that were significantly larger than marginal gaps from crowns milled using a 30 [mu]m spacer setting and generated by dies scanned with the Bluecam, crowns milled using an 80 [mu]m spacer setting and generated by dies scam1ed with the Bluecam, and crowns milled using a 30 [mu]m spacer setting and generated by dies scanned with the inEos Red. After cementation, full contour all-ceramic crowns milled using an 80 [mu]m spacer setting and generated by scanning dies with the Bluecam had marginal gaps that were significantly smaller than marginal gaps from crowns milled using a 30 [mu]m spacer setting and generated by dies scanned with the Bluecam, crowns milled using a 30 [mu]m spacer setting and generated by dies scanned with the inLab, and crowns milled using an 30 [mu]m spacer setting and generated by dies scanned with the inEos Red. Crowns fabricated using an 80 [mu]m spacer setting (Bluecam only) had marginal gaps that did not significantly increase after cementation. Crowns fabricated using a 30 [mu]m spacer setting had marginal gaps that significantly increased after cementation. After cementation, full contour all-ceramic crowns milled using a 80 [mu]m spacer setting and generated by scanning dies with the Bluecam had internal gaps that were similar to the crowns milled using a 30 [mu]m spacer setting and generated by scanning dies with the inLab. However, both these two groups had significantly larger marginal gaps than crowns milled using a 30 [mu]m spacer setting and generated by scanning dies with the Bluecam and crowns milled using a 30 [mu]m spacer setting and generated by scanning dies with the inEos Red. With the CEREC Bluecam, the 80 [mu]m spacer setting delivers better fitting crowns after cementation than those with a 30 [mu]m spacer setting.
Description
PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.
Thesis (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2011 (Department of Restorative Sciences and Biomaterials)
Includes bibliographic references: leaves 113-117.
Thesis (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2011 (Department of Restorative Sciences and Biomaterials)
Includes bibliographic references: leaves 113-117.
License
This work is protected by copyright. Downloading is restricted to the BU community. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.