title: The effects of various clinical factors on marginal enamel micro-cracks produced around composite restoration.
abstract: In this study, enamel micro-cracks produced around composite restorations were observed on surfaces and vertical sections, using a stereomicroscope and a scanning electron microscope (SEM). The effects of various clinical factors, i.e. the curing system, the marginal form and the polishing period after filling, on the incidence of marginal enamel micro-cracks were examined. Enamel micro-cracks were observed on all of the class 1 and 5 composite restorations when the cavity had no marginal bevel and the restorations were polished immediately after filling. Enamel micro-cracks distributed approximately parallel to the cavity margin and located 0.01-0.3 mm from the restored cavity margin. The occurrence of enamel micro-cracks was higher in light-cured composite resin restorations than in chemical-cured ones, for non-beveled cavities when polished 10 min or 24 hours after filling. The occurrence of micro-cracks was reduced by marginal beveling and delayed polishing.
authors.affiliation: Niigata University School of Dentistry, Japan.
authors.forename: L
authors.initials: L
authors.lastname: Han
authors.forename: A
authors.initials: A
authors.lastname: Okamoto
authors.forename: M
authors.initials: M
authors.lastname: Iwaku
mesh_terms: D003188:Composite Resins / Q000009:adverse effects*; D003743:Dental Enamel / Q000648:ultrastructure; D003763:Dental Leakage / Q000209:etiology*; D003775:Dental Polishing; D003793:Dental Restoration, Permanent / Q000379:methods*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D013997:Time Factors
chemical_list: D003188:Composite Resins