Influence of intraoral and laboratory scanning systems on the marginal fit of direct metal laser-sintered copings: An in vitro study.
TL;DR
Copings fabricated from dies scanned using IOS demonstrated significantly lower vertical marginal discrepancies compared to those scanned using the laboratory scanner, however, the marginal gaps observed in both groups were within clinically acceptable limits.
Abstract
Aim
This study aimed to evaluate and compare the vertical marginal discrepancy of DMLS copings fabricated from stone dies scanned using an intraoral scanner (IOS) and a laboratory scanner. SETTINGS AND
Design
An in vitro comparative study was conducted to evaluate the influence of intraoral and laboratory scanning systems on the vertical marginal discrepancy of DMLS copings.
Materials And Methods
A customised stainless-steel model simulating a prepared tooth with a shoulder finish line was fabricated. Impressions of the model were made using elastomeric impression material. Forty dies ( n =40) were poured using type IV dental stone and divided into two groups ( n =20). Group 1 dies were scanned using a 3Shape TRIOS IOS and Group 2 dies were scanned using a 3Shape extraoral laboratory scanner. Copings were fabricated using CAD/CAM software. Marginal gap between the die and the coping was measured at 4 predetermined points (buccal, lingual, mesial, and distal) using a stereomicroscope at ×40 magnification. STATISTICAL ANALYSIS USED Data were analysed using SPSS (version 21, IBM Corp., Armonk, NY, USA). Student's unpaired t-test was used to compare the tested groups. The collected data were analysed at a significance level set at P < 0.05.
Results
The mean marginal gap between the die and coping was 11.44 μm for Group 1 and 29.62 μm for Group 2. The difference between the groups was statistically significant ( P < 0.001).
Conclusion
Copings fabricated from dies scanned using IOS demonstrated significantly lower vertical marginal discrepancies compared to those scanned using the laboratory scanner. However, the marginal gaps observed in both groups were within clinically acceptable limits.
