24 hour polymerization shrinkage of resin composite core materials.
PURPOSE
The study's purpose was to evaluate the 24-hour polymerization shrinkage of resin composite core materials.


MATERIAL AND METHODS
Eleven resin composite core material samples (n = 12) were evaluated using a non-contact imaging device with measurements obtained over 24 h. Shrinkage values were determined corresponding to proposed times involved with CAD/CAM same-day treatment and at 24 h. Shrinkage data was statistically compared using Friedman/Dunn's test for intragroup analysis and Kruskal Wallis/Dunn's test for intergroup analysis, all at a 95% level of confidence (α = 0.05).


RESULTS
Mean results identified a wide volumetric shrinkage range with considerable similarity overlap. Inconsistent shrinkage behavior was evident and all materials reached maximum values before 24 h. No significant difference was observed during proposed digital same day all ceramic crown procedures, but some differences were noted at 24 h.


CONCLUSIONS
Under this study's conditions results were material specific, at times inconsistent, with wide variation. Shrinkage consistently increased for all products and it is not known if the continued shrinkage magnitude may compromise the stability and fit of all-ceramic crowns at 24 h.
['Taylor|Robert|R|', 'Fuentealba|Rodrigo|R|', 'Brackett|William W|WW|', 'Roberts|Howard W|HW|0000-0002-2771-3356']
D003188:Composite Resins D017076:Computer-Aided Design D003776:Dental Porcelain D008422:Materials Testing D058105:Polymerization D013499:Surface Properties
polymerization shrinkage resin composite CAD/CAM resin core material