Assessing the fit accuracy of anatomic full contour monolithic CADCAM crowns and 3 unit FPDs with different materials using an intra-oral scanner on a modified ISO standard die
Date
2014
DOI
Authors
Im, Hyung Gu
Im, Hyunggu
Version
OA Version
Citation
Abstract
OBJECTIVE: The aim of this study is to determine whether the fit of full contour monolithic CAD/CAM restorations made using intra-oral digital scanner will be clinically acceptable.
MATERIALS AND METHODS
Modified ISO/TC106 standard die for a 3 unit FPO was fabricated of aluminum. The modified die was used to fabricate both 3 unit FPDs and single crowns. One scan was made per each group (Group I : FPDs, Group II : single crowns). CEREC Optispray was applied on the die and CEREC Bluecam was used to scan the powder-coated die. A maxillary typodont was used for opposing dentition and was scanned in the same way as the standard die. Single digital impression was made for the 3 unit FPDs. Another scan was made for the single crowns in same manner.
After the 3D images were obtained and processed with the CEREC software 4.2, the restorations were designed for 3 unit FPDs and single crowns.
VITA In-Ceram YZ-40/19 blocks were used for Group I (ZRfp, ZRfm): 3 unit monolithic anatomical full contour zirconia FPDs (n = 5). Single crowns were milled in a same manner as the FPDs. 20 blocks were used for the single crown group (Group II). For Group II-a (ZRc), VITA In-Ceram YZ-20/19 was used, for Group 11-b (EM), IPS e.max CAD for CEREC[R] and inlab[R] LT A1 / C14 was used (n = 5). VITA ENAMIC 1M1 -T EM-14, VITA Mark II 0M1C 114 was used for Group II-c (EN) (n = 5), Group II-d Vita Mark II (MK) (n = 5) correspondingly. Group I, Group II-a specimens were fired according to the manufacturer's instructions in VITA ZyrcomatT furnace after milling. Group II-b specimens were also fired using Ivoclar Vivadent Programat CS furnace after milling according to the manufacturer's instruction.
Internal space discrepancy (test 1) and marginal discrepancy (test 2) was measured for each specimen. For measuring internal space discrepancy, GC FIT CHECKER[R] ADVANCED (FC) was mixed and put in the restoration and the restoration was placed on the ISO die and a load of 50 N was applied on each crown for 30 seconds.
For test 1, volume of the remaining FC film was measured.
For test 2, thickness of the remaining FC film was measured using "replica technique". All the replicas were sectioned vertically into four pieces in mesio distal, bucco-lingual direction through the center of the truncated cone. After the replicas were sectioned, each quarter of the specimens was measured at 3 points. All the measurements were executed at 100X magnification. (object 10X, eyepiece 1OX)
RESULTS
The mean internal discrepancy by volume for Group I was 27.8 mm3 (SD 1.46) for premolars, 26.5 mm3 (SD 1.93) for molars and 27.2 mm3 (SD 1.77) when averaging premolars and molars.
For Group II-a, the mean internal discrepancy by volume was 17.7 mm3 (SD 0.35) before adjustment and 17.5 mm3 (SD 0.15) after adjustment. Group II-b : 27.7 mm3 (SD 8.50), 18.4 mm3 (SD 0.96), Group II-c : 17.7 mm3 (SD 1.36), 21.5 mm3 (SD 2.03), Group 11-d : 21.5 mm3 (SD 5.26), 21.5 mm3 (SD 2.49), before and after adjustment. Group I (ZRfp. ZRfm) had significantly larger value than Group II-a (ZRc, ZRc ad).
Mean marginal discrepancy in thickness for Group I was, ZRfp : 55.4 [mu]m (SD 7.7), ZRfm 31.7 [mu]m (SD 8.9). For Group II-a: 87.5 [mu]m (SD 22.8), 45.1 [mu]m (SD 12.6), Group II-b : 333.8 [mu]m (SD 87.8), 113.1 [mu]m (SD 8.9), Group II-c: 191.5 [mu]m (SD 90.4), 63.0 [mu]m (SD 13.3), Group II-d : 188.5 [mu]m (SD 90.5), 64.6 [mu]m (SD 9.0), before and after adjustment. ZRfm had significantly lower value than ZRfp or ZRc (p [less than] 0.05). Among Group II, EM was significantly larger than any other group (p [less than] 0.01) and ZRc had the lowest mean value of marginal gap.
CONCLUSIONS
Within the limitation of this in-vitro study, the fit accuracy of the CAD/CAM monolithic full contour zirconia 3 unit FPDs and single crowns made on a modified ISO/TC106 standard die by using Bluecam intra-oral scanner was less than 100 [mu]m and thus, clinically acceptable. [ ZRfp: 55.44 [mu]m (SD 7.69 [mu]m), ZRfm : 31.67 [mu]m (SD 8.91 [mu]m), ZRc: 87.48 [mu]m (SD 22.80 [mu]m), ZRc ad : 45.09 [mu]m (SD 12.57 [mu]m)]
However, the fit accuracy of the CAD/CAM monolithic full contour IPS e.max CAD, VITA ENAMIC, VITA Mark II single crowns was over 100 [mu]m, so it was not clinically acceptable before adjusting.
[ EM : 333.8 [mu]m (SD 87.79 [mu]m), EN : 191.49 [mu]m (SD 90.43 [mu]m), MK: 188.53 [mu]m (SD 90.46 [mu]m)]
Description
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Dissertation (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2014 (Department of Restorative Sciences and Biomaterials).
Includes bibliographic references: leaves 65-73.
Dissertation (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2014 (Department of Restorative Sciences and Biomaterials).
Includes bibliographic references: leaves 65-73.
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.