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Evaluation of Dental Composite Shrinkage and Leakage using X-Ray Microcomputed Tomography



Diana N. Zeiger, Jirun Sun, Gary E. Schumacher, Sheng Lin-Gibson


Polymerization shrinkage of dental composites results in leakage and may lead to secondary caries and restoration failure. This study tested the hypothesis that shrinkage and sites of potential leakage in human teeth evaluated using X-ray microcomputed tomography (μCT) follow the same patterns previously observed in model cavities. Two holes of equal volume but different dimensions were drilled into the exposed dentin of extracted human molars. The cavities were filled with composite and teeth were scanned, before and after curing, using μCT. Three-dimensional (3D) reconstructions of the data showed that cavity geometry did not affect the polymerization shrinkage. Potential leakage sites were identified by gap formations and found to be non-uniformly distributed along the tooth-composite interface. Visualization of sectioned samples with confocal laser scanning microscopy confirmed leakage in regions calculated by μCT. This study demonstrates that μCT is a powerful, non-destructive method for determination of leakage and its distribution in teeth.
Journal of Dental Research


1/4CT, composite, leakage, polymerization shrinkage, image analysis


Zeiger, D. , Sun, J. , Schumacher, G. and Lin-Gibson, S. (2009), Evaluation of Dental Composite Shrinkage and Leakage using X-Ray Microcomputed Tomography, Journal of Dental Research, [online], (Accessed June 20, 2024)


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Created August 23, 2009, Updated October 12, 2021