title: Clinical performance of polyacid-modified resin restorations using "softstart-polymerization".
abstract: This study investigated the influence of "softstart-polymerization" on the clinical performance and marginal integrity of polyacid-modified resin restorations (PMR) in class V cavities. Eighty PMR restorations were placed in 20 patients [40 Dyract (DY); 40 Hytac (HY)] with (npat = 10) and without preparation (npat = 10). Restorations were light cured for 40 s either conventionally (CP) or with a lower light intensity for the first 10 s (SSP). Each patient received four restorations (DY-CP, DY-SSP, HY-CP, HY-SSP), which were examined clinically according to modified USPHS criteria, and by quantitative SEM-analysis after 7 days (baseline), 6 months and 1 year. Statistical analysis was performed using the Mann-Whitney-U test (P < or = 0.05) and error rates method. Clinically, no restoration showed recurrent caries or crevices. After 1 year, margins of 24-47% of the HY- and 36-53% of the DY-restorations were rated "Bravo". Marginal discoloration occurred in 20-37% in HY- and in 18-21% in DY-restorations. The error rates method revealed no significant differences between materials or between polymerization modes with and without preparation. Pairwise testing showed that without preparation, the marginal adaptation to dentin was significantly worse compared to enamel for HY with both polymerization modes, for DY with SSP. With preparation, no significant differences were found. Cavity preparation may have an influence on differences in marginal quality between enamel and dentin.
authors.affiliation: University of Regensburg, Dental School, Department of Operative Dentistry and Periodontology, Germany. heinrich.oberlaender@klinik.uni-regensburg.de
authors.forename: H
authors.initials: H
authors.lastname: Oberländer
authors.forename: K H
authors.initials: KH
authors.lastname: Friedl
authors.forename: G
authors.initials: G
authors.lastname: Schmalz
authors.forename: K A
authors.initials: KA
authors.lastname: Hiller
authors.forename: A
authors.initials: A
authors.lastname: Kopp
mesh_terms: D020770:Compomers / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D003731:Dental Caries / Q000517:prevention & control; D003737:Dental Cavity Preparation; D003743:Dental Enamel; D018772:Dental Marginal Adaptation; D003804:Dentin; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008027:Light; D008689:Methacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D011108:Polymers / Q000737:chemistry; D055502:Secondary Prevention; D017640:Silicates / Q000737:chemistry*; D016037:Single-Blind Method; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013674:Technology, Dental / Q000379:methods; D014783:Viscosity
chemical_list: D020770:Compomers; D003188:Composite Resins; C088486:Dyract; D005899:Glass Ionomer Cements; D008689:Methacrylates; D011108:Polymers; D017640:Silicates; C105429:hytac