6 октября, 2015 
Malyar Eberhard W. Neuse and Eliakim Mizrahi
University of the Witwatersrand, Johannesburg, South Africa
The success of modern restorative dentistry in the repair, restoration, and replacement of tooth structure is critically dependent on the availability of specialized metallic and nonmetallic materials and on procedures for their proficient application. Most of the non — metallics are polymeric in nature, and on a volume basis, the greatest share by far of these polymeric materials find use in the construction of dentures, and to a lesser extent also in the preparation of impression materials and prosthetic restorations such as crowns or bridges. Materials of this type do not display adhesive functions; at best, they may act as adherends. Yet there are different procedures, generally in operative dentistry, where certain polymers, sometimes in combination with inorganic compounds, have come to assume leading roles as active participants in adhesion processes in addition to other vital functions associated with their particular applications in restorative and preventive dentistry. In the classification of the FDI (Federale Dentaire Internationale), polymers of this type fall under the description of group Ml (dental filling and related materials) and include such items as luting agents, cavity liners, pit and fissure sealants, and finally, the important class of cavity-filling cements. Although some of these materials truly conform to the characteristics of an adhesive—namely, to bond two surfaces together—others, such as the cavity-filling cements, are in a sense half-sided adhesives insofar as they bond to one adherend surface only; yet they are included here because their one-sided bonding represents a realistic process of retention. The bonding reaction may involve mechanical interlocking, and this is indeed the mechanism utilized in the majority of adhesion processes encountered in dentistry. Alternatively, it may involve a chemical, generally ionic or covalent, bond-forming process, which one finds invariably coupled with smaller or larger contributions by the mechanical retention mode.
To facilitate presentation and digest of the subject, this chapter has been subdivided into four main sections in accordance with fields of application rather than composition of materials. Brief discussions of the applications and materials requirements are followed in each category by presentations of the working materials of choice, their mode of action, and where applicable, their strong and weak points in performance. In view of the abundance of publications in the field of dental materials, no attempt has been made to provide a comprehensive compilation of references. Instead, preference has been given to the citation of selected recent publications by leading specialists, in which reference has been made to previous work on the subject. Fundamental facts and relationships presented as background information, which are considered textbook knowledge, have not been referenced. Exemplifying texts to be consulted for details are those of McCabe [1] and Wilson et al. [2].
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