[Dental-prosthetic margin in bonded esthetic restorations. Clinical aspects].

The long term success of any bonded prosthesis mainly depends on the quality of the marginal adaptation. Its degradation has been noted both at the clinical and the experimental levels. It may be due to biological, chemico-physical, mechanical and clinical factors. Improving the marginal gap closure is based on some principles: the type of preparations on which depends the stabilisation and the good positioning of the restorations; the quality of the clinical isolation which will avoid any humidity on the bonded surfaces (saliva, blood, gingival fluids); the chemical and physical type of the bonding polymer and the quality of its polymerisation; the finishing and final surface condition directly related to the kind of finishing burs used. The understanding and application of these few clinical principles enable the practitioner to expect a better clinical result as regards the bonding of aesthetic restorations.