Factors contributing to the incompatibility between new adhesive systems and various composite resin restorations Dr. F. Maleknejad* - Dr. H. Moosavi** *- Associate Professor of Operative Dentistry Dept. - Faculty of Dentistry – Mashhad University of Medical Sciences. **- Assistant Professor of Operative Dentistry Dept. - Faculty of Dentistry – Mashhad University of Medical Sciences. Background and Aim: Although light cured composites are easily accessible, self/dual-cure cements and composite resins also have broad clinical applications. The aim of this study was to evaluate the incompatibility between new adhesives and different types of cement and composite resin restorations and their effects on interface bond strength. Materials and Methods: All articles and theses on adhesives and cement/composite resin restorations up to June 2005, available at Mashhad dental school library, medline and other internet information banks were collected and evaluated. Conclusion : Some two–step-total-etch and one–step-self–etch adhesives were incompatible with self/dual–cured cements and composite resins. This is due to the large concentration of acidic, ionic and hydrophilic resin monomers that result in adverse chemical interactions and increased permeability of these adhesives. In order to prevent the adverse acid-base chemical interactions between simplified adhesives, light cured cements or composites or dual cured adhesives containing catalysts should be used. For neutralizing the permeability effect of simplified adhesives, light cured composites or a single layer of unfilled resin bonding or flowable composites should be applied over the adhesive layer to induce rapid curing. Key words: Composite adhesive - Permeability - Incompatibility - Self-etch | 
