[Osseointegrated implants in clinical dentistry from the point of view of prosthodontics].

With the life expectancy of our country reaching 80s we are encountering a society with greater proportion of the population in old ages. This social problem creates a relatively important assignment in the area of prosthodontics, especially in full denture prosthodontics. Though the most important factor that affects the success or failure of full denture prosthodontics is the condition of the residual ridge, recent studies have shown that the residual ridges continue to resorb throughout one's life span. Also our survey on the present Japanese denture patients tells us that an average person becomes edentulous at an age of 57.6, has made a full denture twice or more, has worn the denture for 8 to 10 years, and by age 65 to 67 over half of the patients have their mandibular residual ridges being even or the ridge has resorbed extremely so that the ridge is actually lower than the floor of the mouth. With the situation as it is, when we look into the future of the full denture prosthodontics it is inevitable that there will be a rapid increase in patients with extremely resorbed ridges which the present theory of full denture prosthodontics could not handle. In this sense, prosthodontic treatment of edentulous patients with implants is a relatively interesting field. In this article we will comment of the basic application technique and the prosthodontic technique which we have improved of the Brånemark's Osseointegrated implants which possess the long term basic objective clinical data and whose long term safety has been established in edentulous patients. First we will explain the basic application technique using a real case. The patient was a 56 years old female. She came to the clinic with the chief complaint of severe masticatory dysfunction due to unstable full dentures. She strongly desired fixed prosthodontics. She had worn dentures for the past 17 years. The dentures that she had on when she came in for the first visit were her 4th set of dentures. For the past 8 years she had her dentures adjusted and rebased repeatedly. Her maxillary residual ridge had an average height but her mandibular residual ridge was extremely resorbed. EMG examination exhibited conspicuous distortion in chewing rhythm. From the mandibular movement, radiographs of the TMJ regions and the clinical observations it was determined that the vertical dimension had been lost and that her mandible was displaced toward her left and anteriorly. Palpation indicated the condition of muscular tension similar to that of TMJ dysfunction patients.(ABSTRACT TRUNCATED AT 400 WORDS)