A WITHIN-SUBJECT COMPARISON OF MANDIBULAR LONG-BAR AND HYBRID IMPLANT-SUPPORTED PROSTHESES - PSYCHOMETRIC EVALUATION AND PATIENT PREFERENCE

Although it has been shown that patients are more satisfied with prost heses supported by implants than with conventional dentures, there hav e been few direct comparisons of the various designs of implant-suppor ted prostheses. This within-subject crossover clinical trial was desig ned to compare two forms of removable prostheses which are frequently prescribed for the edentulous mandible: a long-bar overdenture support ed by 4 implants and a two-implant hybrid overdenture. Sixteen complet ely edentulous subjects were given a new maxillary conventional dentur e: Ten of them received the mandibular long-bar prosthesis first and s ix the hybrid. After a two-month adaptation period, psychometric measu res of various aspects of the prostheses and physiological tests of ma sticatory efficiency were carried out over three weeks. The mandibular prostheses were then changed and the procedures repeated. At the end of the study, subjects were asked to choose the mandibular prosthesis that they wished to keep, and final psychometric measures were taken. In this paper, the results of the psychometric assessment and patient preference are presented. Subjects assessed factors such as general sa tisfaction, quality of life, stability, retention, comfort, esthetics, ease of cleaning, speaking, and chewing, and how well-chewed foods we re before being swallowed. Most of the factors except ease of cleaning and speaking were rated significantly better with long-bar overdentur es than with hybrid ones. These results are consistent with the fact t hat all subjects chose long-bar overdentures, reporting stability, eas e of chewing, and comfort as the most important factors influencing th eir choice. These results suggest that, although subjects assign high ratings for most factors to hybrid overdentures, they find long-bar ov erdentures to be significantly more stable, comfortable, and easier fo r chewing.