A RADIOGRAPHIC AND SCANNING ELECTRON-MICROSCOPIC STUDY OF APPROXIMAL MARGINS OF CLASS-II RESIN COMPOSITE RESTORATIONS PLACED IN-VIVO

Introduction: Clinical studies on the quality of Class II amalgam and resin composite restorations frequently report defective cervical marg ins. Aim: The aim of this study was to evaluate the quality of the app roximal margins of Class II resin composite restorations placed in viv o using various application techniques and adhesive systems. Materials and Methods: Class II restorations were placed in premolar teeth in v ivo, using different adhesive systems and application techniques. Afte r extraction of the teeth, the restorations were evaluated radiographi cally and by SEM. Results: One-hundred and forty-four resin composite Class II restorations were evaluated. According to the radiographs, 4% of the restorations were overfilled and 33% were underfilled. SEM pic tures revealed that 43% of the restorations were overfilled and 25% un derfilled. Thirty-two per cent of the restored teeth showed a flash of bonding agent on the approximal surface. Conclusions: Class II resin composite restorations placed in vivo may be found frequently to show imperfect cervical margins. Overextended margins observed by SEM are d ifficult to detect on radiographs. When seen on a radiograph, a thick layer of bonding agent may be interpreted as an underfilled restoratio n. (C) 1998 Elsevier Science Ltd. All rights reserved.