Bond Strengths of Metal, Ceramic and Polymer Brackets in Combination with Different Enamel Preconditioning Methods

The introduction of adhesive systems for orthodontic bonding has dramatically decreased a time consuming step in fixed appliance therapy. Since the introduction of the adhesive technology by Buonocore in 1955 and the first report of its use in bracket placement by Newman  in 1964, there have been considerable developments in all areas. Enamel etching was first performedwith 80% phosphoric acid but soon changed to a 37% solution, which was routinely accepted by the end of the last millennium. Subsequently the introduction of self-etching primers has again brought a dramatic change in etching technology. 

Not only were new etching agents such as polyacrylic acid and maleic acid introduced, but the etchant was combined with the low viscosity composite matrix which potentially enhanced the penetration of the etching relief. Alongside the etchants, adhesives have also evolved. Whereas initially Newman advocated the use of an epoxy resin, polyacrylic resins filled with different an organic fillers are more commonly used today. Finally the use of new materials in bracket manufacturing, such as different ceramics and polycarbonates also emphasizes the ongoing development and research in adhesive technology. Read more................