title: Interfacial adaptation of in vivo aged polyacid-modified resin composite (compomer) restorations in primary molars. A SEM evaluation.
abstract: Polyacid-modified resin composite (PMC) restorations are being increasingly used in class II cavities in primary teeth. The aim of this study was to evaluate the interfacial adaptation of 1-month- and 30-month-old in vivo restorations by quantitative scanning electron microscopy (SEM) evaluation. Twelve PMC restorations were performed under clinically controlled conditions in primary molars planned for extraction 1 month later for orthodontic reasons. Eleven other PMC restorations, aged 30 months (range 1.5-3 years) and part of a multicenter study, were collected after exfoliation. To observe the interfacial adaptation of each restoration at several levels a thin layer of the proximal surface was ground off 2-3 times. Replica impressions of each level were prepared for SEM. The interfaces of the replicas were evaluated at x200 and x1000. In the 1-month-old restorations gap-free adaptation to enamel was found in 87% and to dentin in 84% of the total interfacial length investigated. For the 30-month-old restorations gap-free adaptation was registered in 59 and 63%, respectively. The interfacial quality was significantly better in the 1-month-old restorations than in those 30 months of age. Adaptation to enamel was significantly better in the cervical part of the 1-month-old restorations than in the axial walls, whereas there was no significant difference in dentin. No significant difference was found between the cervical and axial cavity walls of the 30-month-old restorations. Enamel fractures were registered in 31 and 24%, respectively of the interfacial length of the 1-month- and 30-month-old restorations. The corresponding findings in dentin were 0 and 0.9%. It can be concluded that restorations aged for a short time showed a high percentage of sealing, which decreased significantly for the 30-month-old ones.
authors.affiliation: Department of Oral Biology, Faculty of Odontology, Umeå University, Sweden. Ingrid.Andersson-Wenckert@oralbio.umu.se
authors.forename: I E
authors.initials: IE
authors.lastname: Andersson-Wenckert
authors.forename: J W
authors.initials: JW
authors.lastname: van Dijken
authors.forename: P
authors.initials: P
authors.lastname: Hörstedt
mesh_terms: D000704:Analysis of Variance; D002675:Child, Preschool; D020770:Compomers; D003188:Composite Resins / Q000737:chemistry; D003743:Dental Enamel / Q000000981:diagnostic imaging; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000379:methods; D003804:Dentin / Q000648:ultrastructure; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008689:Methacrylates; D008855:Microscopy, Electron, Scanning; D008963:Molar; D017640:Silicates; D018709:Statistics, Nonparametric; D013997:Time Factors; D014094:Tooth, Deciduous; D014463:Ultrasonography
chemical_list: D020770:Compomers; D003188:Composite Resins; C088486:Dyract; D005899:Glass Ionomer Cements; D008689:Methacrylates; D017640:Silicates