3D non-destructively Evaluation of microleakage induced by polymerization of dental composites

Jirun Sun and Sheng Lin-Gibson

Polymeric composites are increasingly drawing attention as dental restoratives because of their good mechanical and aesthetic properties; however, their long term performance remains inadequate and frequently results in costly replacement procedures. More than half of these replacements are due to the formation of secondary caries in which microleakage (gaps between the tooth and composites) is strongly susceptible to bacteria infiltration leading to tooth decay in the restorative material interface. This research evaluates microleakage formation and mechanisms using X-ray microcomputed tomography (mCT) with the aid of fiduciary markers. By comparing the volume and position of composites before and after polymerization, gaps between composites and walls of sample holders (model polymethyl methacrylate cavities) are calculated, and thus the microleakage is evaluated. Results from mCT are compared with those from dye penetration methods. Effects of sample volumes, configuration factors (C-factors, defined as the ratio of bonded to unbonded area), and geometries are discussed using microleakage results determined by mCT. Financial support was provided through an NIDCR/NIST Interagency Agreement Y1-DE-7005-01.

Jirun Sun,

Mentor: Sheng Lin-Gibson

Biomaterials Group, Polymers Division, MSEL

Room A111, Building 224, Mail stop 8543

Tel: (301)975-5439

Fax: (301)975-4977

jsun@nist.gov

not a member of Sigma Xi

 

Poster Category:  Materials