[Failure-time and risk analysis of fixed partial dentures]. / Verweilzeit- und risikofaktorenanalyse von festsitzendem Zahnersatz.

Statistical methods of survival-analysis were applied to investigate the effects of anatomical, constructional and individual factors, which determine the "life-time" of 4371 single crowns, 1669 bridges and 175 fixed splints of a total of 1841 patients of a private insurance company. After 15 years of service 64% of the bridges, 56% of the single crowns and 45% of the splints were still under risk. The number of abutments and units, location, date of insertion, jaw and extension/normal bridge were significant risk factors.

[Clinical long-term results with bonded bridges]. / Klinische Langzeitbefunde bei Adhasivbrückenpatienten.

788 patients with 3-unit resin-bonded bridges were followed up over a time period of up to 5 years after placement. In this multicenter study, the following clinical variables were analyzed: caries, periodontal disease, loss of pulp vitality and the behavior of the dental materials involved were assessed. Adverse findings were rare. More data are needed over a longer period of time to support the present results.

[Risk factors for three-unit bonded bridges]. / Risikofaktoren dreigliedriger Adhäsivbrücken.

Statistical methods of survival-analysis were applied to investigate the effects of anatomical factors and clinical procedures which determine the "life-time" of 3-unit adhesive bridges. Their influences were analyzed until the first loss of retention after insertion. Besides the therapist effect, increased mobility and macromechanical preparation of the abutments could be identified as significant variables. Bridges bonded to one non-mobile and one hypermobile abutment tooth were found to be especially threatened. Extensive macromechanical preparation of the hard tissues reduces the hazard of debonding remarkably; this effect may be replaced by improved retentive mechanism of retainers.