Implant-supported single-tooth replacements: risk of implant and prosthesis failure.

Data from 236 patient cases of implant-supported single-tooth replacements in the maxillary anterior region were sequentially recorded and documented. The time in situ ranged from a minimum of five to a maximum of 19 years. Twenty-two implants failed during the observation period. The causes of such failure were peri-implantitis, implant fracture, and trauma. The probability of success according to the Kaplan-Meier method decreased to 0.89 over a period of 10 years. The failure rate for implants replacing lateral incisors was lower than that for implants replacing central incisors. Seventy-six cases were clinically documented for 10 years or more. In 15 cases, replacement of the prosthetic superstructure was necessary during the 10-year period. The course of therapy and clinical follow-up care is described by a multi-state distribution.

[Long-term success of various implant types--a study over 15 years]. / Langzeiterfolge verschiedener Implantattypen--eine 15-Jahres-Studie.

This study reports the clinical success rates of 6 different implant types inserted with defined clinical indications. The criterium used was implant loss. The survival periods of a total of 1723 implants were statistically evaluated according to Kaplan and Meier's method in relation to the type of implant used and the indication chosen.

[The significance of generally accepted rules and their criteria in the discussion on the quality of dental treatment]. / Die Bedeutung allgemein anerkannter Regeln und ihrer Kriterien für die Qualitätsdiskussion in der Zahnmedizin.

The significance of generally accepted rules and their criteria in the discussion on the quality of dental treatment is pointed out. The fact that dental treatment is based not only on empirical but to a great extent also on hypothetically established rules emphasizes the importance of epidemiologic clinical research. Dental treatment cannot be considered purely under the aspects of mechanics. The consideration of dental activities by mechanical and technical parameters alone is not permissible, because this approach disregards the non-mechanical nature of dental interventions.

[Considerations in weighing dental intervention]. / Die Wägbarkeit des zahnärztlichen Eingriffes.

The dental operation as an intervention in the physical and psychical integrity of human beings is controlled by three main regulators: the concurrence of dental treatment with scientific knowledge, its accordance with the law to secure dental treatment and its supervision by law. The significance of these three regulators for the weigheability of dental operations is described and analyzed.

[Prognosis of abutment teeth in severely reduced residual dentitions]. / Die Prognose von Pfeilerzähnen bei stark reduziertem Restzahnbestand.

The survival rate of 2094 abutment teeth in 671 removable partial denture cases was analysed. Within an interval of 2-7 years 150 abutments were lost. The survival-rate of abutments in severely reduced dentitions differs significantly from that in dentitions with more than 3 teeth. Regarding the framework design there was no significant difference in the survival-rate of abutment teeth for removable partial dentures supported by more than 3 teeth.

[Occlusal margin quality of Cerec-inlays several months after insertion]. / Okklusale Randschlussqualitat von Cerec-Inlays nach mehrmonatiger Tragedauer.

The quality of the occlusal margins of 58 computer-machined ceramic inlays (Cerec) was examined by SEM. The adhesion of the luting composite to enamel and to the inlay appeared more of less stable. However, the wear of the composites was substantial and more pronounced in Brilliant and in Microfill pontic C than it was in Heliomolar.

[Prognosis of periodontally reduced abutment teeth under removable dentures]. / Die Prognose von Pfeilerzähnen mit reduziertem Parodont bei herausnehmbarem Zahnersatz.

The extraction rate was studied in a group of 151 patients treated for periodontal and prosthodontic reasons. 29 of 588 abutments had to be extracted due to periodontal problems within a period of 6 years after prosthodontic treatment. The initial findings of the extracted teeth are correlated with the initial findings of all abutments. It can be shown that periodontally reduced teeth involve a higher risk of extraction; nevertheless, in the majority of the cases, they could be successfully used as abutments.

[Electronic analysis of the limits of mandibular movement]. / Elektronische Analyse der Unterkiefergrenzbewegung.

In this investigation, the speed and acceleration of the movement limit of the mandible were registered electronically for the first time. Beginning with the registration of the path alteration via the time, the first and second differential quotient was formed using a special electronic experimental apparatus; this quotient was then represented as a curve. The experimental apparatus facilitates a deeper understanding of microscopic alterations in the movement of the mandible.

[Electronic studies on the biological tolerance of the mandibular movement limits]. / Elektronische Untersuchungen zur biologischen Toleranz der Unterkiefergrenzbewegungen.

Three-dimensional synchronized position-limits of the mandible were electronically derived and evaluated in 10 adult subjects with normal mastication. It was shown that the respective positions could not be identically reproduced. To define this physiologic distribution, parameters were introduced with which the biologic tolerance and the reproducibility of the position-limits of the mandible can be described in the first approach.

[Systematic studies on decision making in dental therapy]. / Arbeitssystematische Untersuchungen zur Therapiefindung in der Zahnheilkunde.

The decision for restorative treatment was analyzed in this study, and models were discussed. As model of the first approach, the dental treatment was reproducible, but the findings should not be considered universally valid since psychic factors were not considered.