Treatment outcomes with implant-supported overdentures: Clinical considerations (original) (raw)

1998, The Journal of Prosthetic Dentistry

Adapt ation to wearing complete dentures is a complex process and must be considered from both somatic and psychologic standpoints. Incorporating a foreign body in the oral cavity may be a difficult task. Documentation on success and failure with complete dentures is sparse and not reliable, because the correlation between a favorable shape of the residual ridge, the technical accuracy of the dentures, and the ease of adaptation to wearing dentures is low. 1,2 Motor skills tend to decrease with increasing age. The difficulties of wearing dentures has been attributed to deficiencies of the denture-bearing tissues, reduced salivary flow, vulnerable tissue, and severe ridge resorption. Patients may also have an aversion against a foreign body in the oral cavity. For many patients, the wearing of complete dentures also means to be old and socially handicapped. Problems with adaptation to complete dentures are observed with a higher incidence for mandibular dentures than for maxillary dentures. Historically, surgeons focused on improving the structure of the residual mandibular ridge by various preprosthetic surgical techniques and less frequently the maxillary ridge. These techniques appear to be more invasive than the surgery for osseointegrated implants, and there is no scientific evidence of its success and usefulness. The use of implants to substitute for missing teeth was systematically developed by Brånemark et al. 3,4 Since the 1980s, several studies have demonstrated the reliability of this treatment modality. 5-7 The clinical concept of this treatment consisted of inserting five to six implants into the edentulous mandible to provide support and retention for a fixed prostheses, which was retrievable by the dentist only. While the Brånemark groups focused on fixed prostheses, Schroeder et al 8-10 developed the ITI implant system to deal with the problems of unilateral distal extension situations. He suggested that overdentures supported by four implants should be used in situations of