Performance of Class I composite restorations when polished immediately or after one-day water storage

• Published in: PloS one Vol. 12; no. 8; p. e0183381
• Main Authors: Irie, Masao, Maruo, Yukinori, Nishigawa, Goro
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 17.08.2017; Public Library of Science (PLoS)
• Subjects: Adhesive bonding; Biology and Life Sciences; Bond strength; Composite materials; Composite Resins; Composition; Curing; Dental fillings; Dental Polishing; Dentin; Dentistry; Enamel; Engineering and Technology; Finishing; Flexural strength; Humans; Inspection; Interfacial bonding; Light; Mechanical properties; Medicine and Health Sciences; Modulus of rupture in bending; Molds; Physical Sciences; Polymerization; Polytetrafluoroethylene; Research and Analysis Methods; Restoration; Storage; Studies; Teeth; Water; Water storage; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0183381

This study investigated the effects on gap formation in Class I restorations (observed by vertical and horizontal forms of inspection) and on the mechanical properties of nine resin composite filling materials when the restorations were subject to finishing immediately after setting or after one-day water storage. Class I restorations with resin composite fillings were polished either immediately (3 min) after setting or after one-day water storage. Interfacial gap formation (observed by vertical inspection) was assessed using 14 gap measurement points along the interface between the restoration and cavity walls and floor (n = 10 per resin composite; total points measured per time point = 140). For marginal gaps formed at cavosurface margins in Class I cavities and in Teflon molds, marginal gap formation (observed by horizontal inspection) was assessed by measuring the maximum gap-width and opposing width (if any). Effects on mechanical properties were assessed by measuring shear bond strengths to enamel and dentin, flexural strength and modulus. After one-day storage, marginal gap-widths in Class I restorations were significantly decreased for all composites, alongside a significant increase in shear bond strengths to enamel and dentin, flexural strength and modulus. Resin composite-filled Class I restorations which were polished after one-day delay presented lower gap formation compared with finishing immediately after setting.