Lee J-W, Park J-M.
Evaluation of marginal and internal gap under model-free monolithic zirconia
restoration fabricated by digital intraoral scanner
Journal of Korean Acad Prosthodont. 2016;54(3):210-7. PURPOSE.
The aim of this study was to evaluate the marginal and internal adaptation of monolithic zirconia
restoration made without physical model by digital intraoral scanner
.MATERIALS AND METHODS.
A prospective clinical trial was performed on 11 restorations as a pilot study. The monolithic zirconia
restorations were fabricated after digital intraoral impression taking by intraoral scanner
(TRIOS, 3shape, Copenhagen, Denmark), computer-aided designing, and milling
manufacturing process. Completed zirconia crowns were tried in the patients’ mouth and a replica technique was used to acquire the crown-abutment replica. The absolute marginal discrepancy, marginal gap, and internal gap of axial, line
angle, and occlusal part were measured after sectioning the replica in the mesiodistal and buccolingual direction
. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U test (a=.05).RESULTS.
From the adaptation analysis by replica, the statistically significant difference was not found between mesiodistal and buccolingual sections (P>.05), but there was significant difference among the measurement location (P<.01). The amount of absolute marginal discrepancy was larger than those of marginal gap and internal gap (P<.01).CONCLUSION.
Within the limitations of this study, the adaptation accuracy
of model-free monolithic zirconia
restoration fabricated by intraoral scanner
exhibited clinically acceptable result. However, the margin of zirconia crown showed tendency of overcontour and cautious clinical application
and follow up is necessary.