J.A. von Fraunhofer

Filled diacrylate resins have been found to satisfactorily bond metal gauze-backed orthodontic attachments directly to enamel. Polymeric materials do not bond to stainless steel and usually gauze is welded to brackets and other attachments to provide mechanical retention. Gauzes of various mesh sizes were welded to orthodontic buttons and the bond strength to etched human enamel determined. It was found that the mesh size of the gauze affects the bond strength between the orthodontic button and enamel.

The phenomena of adhesion and cohesion are reviewed and discussed with particular reference to dentistry. This review considers the forces involved in cohesion and adhesion together with the mechanisms of adhesion and the underlying molecular processes involved in bonding of dissimilar materials. The forces involved in surface tension, surface wetting, chemical adhesion, dispersive adhesion, diffusive adhesion, and mechanical adhesion are reviewed in detail and examples relevant to adhesive dentistry and bonding are given. Substrate surface chemistry and its influence on adhesion, together with the properties of adhesive materials, are evaluated. The underlying mechanisms involved in adhesion failure are covered. The relevance of the adhesion zone and its importance with regard to adhesive dentistry and bonding to enamel and dentin is discussed.