Alghazzawi TF, Al-Samadani KH, Lemons J, Liu PR, Essig ME, Bartolucci AA, Janowski GM. Effect of
imaging powder and CAD/CAM stone types on the marginal gap of zirconia crowns.
J Am Dent Assoc 2016;
146:111-20. [PMID:
25637209 DOI:
10.1016/j.adaj.2014.10.006]
[Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 10/18/2014] [Accepted: 10/21/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVE
To compare the marginal gap using different types of die stones and titanium dies with and without powders for imaging.
METHODS
A melamine tooth was prepared and scanned using a laboratory 3-shape scanner to mill a polyurethane die, which was duplicated into different stones (Jade, Lean, CEREC) and titanium. Each die was sprayed with imaging powders (NP, IPS, Optispray, Vita) to form 15 groups. Ten of each combination of stone/titanium and imaging powders were used to mill crowns. A light-bodied impression material was injected into the intaglio surface of each crown and placed on the corresponding die. Each crown was removed, and the monophase material was injected to form a monophase die, which was cut into 8 sections. Digital images were captured using a stereomicroscope to measure marginal gap. Scanning electron microscopy was used to determine the particle size and shape of imaging powders and stones.
RESULTS
Marginal gaps ranged from mean (standard deviation) 49.32 to 1.20 micrometers (3.97-42.41 μm). There was no statistical difference (P > .05) in the marginal gap by any combination of stone/titanium and imaging powders. All of the imaging powders had a similar size and rounded shape, whereas the surface of the stones showed different structures.
CONCLUSIONS
When a laboratory 3-shape scanner is used, all imaging powders performed the same for scanning titanium abutments. However, there was no added value related to the use of imaging powder on die stone. It is recommended that the selection of stone for a master cast be based on the hysical properties.
PRACTICAL IMPLICATIONS
When a laboratory 3-shape scanner is used, the imaging powder is not required for scanning die stone. Whenever scanning titanium implant abutments, select the least expensive imaging powder.
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