New dental restorative materials: research and practice.

Practitioners spent a lot of time replacing or performing resin restorations due to recurrent caries formation. Antibacterial-containing dental adhesives may have therapeutic effects, working as an additional source to reduce recurrent caries development in patients with highrisk of caries. Antibacterial properties in adhesive systems or composites are considered a viable option. Besides resin monomers, chemical initiators and organic solvents, dental adhesives may contain filler, fluoride, desensitizing or antimicrobial agents. The antibacterial properties of these agents and their effects on physical strength and long-term performance of dental restorations have been investigated. Commercially available resin-based composites/adhesive systems show antibacterial activity, this is normally only an adverse reaction of the components of the composites and the inhibitory effect against bacteria is unlikely to be reliable. According to examination by scanning electron microscope of the resin-based composite/ adhesive systems bond to dentin, the adhesive layer or hybrid layer is usually only 2 to 5 μmthick between the dentin wall and the bonding surface of resin-based composite restoration. The biggest challenge in the development of antibacterial dental adhesives is leakage at the interface between tooth surface and restorative material, leading to secondary caries. Bonding of dentin to the restoration has been shown to be even more challenging for successful restoration. Future developments should focus on dental adhesives with synergistic effects that will not only replace missing volume but also will have bioactive and therapeutic properties. Through multidisciplinary efforts, the development of antimicrobial dental adhesives promises tremendous advances. Keywords: resin restorations, dental adhesives, hybrid layer, bioactive.