Salvage of a Blade‐Implant Bridge Thomson, David H.
Australian dental journal,
September 2001, Letnik:
46, Številka:
3
Journal Article
Recenzirano
Odprti dostop
This paper describes an aesthetic and functional treatment for the replacement of a failing bridge supported by blade implants where the patient refused further surgery
The aim of this study is to investigate the thermal stresses caused by temperature change on the upper canine coated by various dental materials. In this study, first of all the modeling of tooth has ...been done by using a specific computer program Ansys 5.3 that is capable of both finite element modeling and stress-strain analysis. Secondly, themal stresses arising from the temperature difference between the tooth temperature and the temperatures of the food and drinks taken to mouth have been examined. It has been demonstrated that the lowest thermal stresses occur in metal crowns, while the highest thermal stresses occur in metal- ceramic crowns. It has been shown that metal-ceramic crowns are more prone in terms of heat compared to metal crowns and that these crowns may deteriorate in time and may even become unusable.
The corrosion behaviour of eight commercial high-Pd alloys was investigated and compared to that of Pd-Ag systems. They were tested with standard potentiodynamic techniques in 0.9 per cent saline ...solution and an artificial saliva. The corrosion behaviour of the high-Pd alloys was satisfactory and essentially equivalent. In more systems anodic overloading in 0.9 per cent saline in this alloy group seemed to be superior compared to the Pd-Ag alloy group. Within the high-Pd alloy systems compositional and constitutional variations were apparently too small to result in substantial electrochemical effects.
In the present retrospektive study the situation of the natural crown as well as the restoration types placed prior to endodontic treatment was examined.
A total of 782 teeth from 545 patients (54.3% ...men; 45.7% women; mean age: 49.9 +/- 12.1 years) were investigated. In addition to the evaluation of the medical history of the patients, x-rays and a clinical investigation were carried out in order to assess the clinical condition of the crown as well as the restoration types. Of special interest were: carious lesions, composite fillings, amalgam, ceramic or gold crowns and/or bridge restorations.
305 of the examined teeth were located in the mandible and 477 in the maxilla. 26.3% of the teeth were anteriors, 31.2% were premolars and 42.5% were molars. 24.2% of the teeth were restored with metal ceramic crowns, 15.1% were restored with gold cast crowns or served as abutment teeth for bridgework; untreated caries was found in 21.1%, and composite fillings were found in 13.7% of the cases. 23.8% of the front teeth, 26.6% of the premolars and 22.6% of the molars showed a metal ceramic restoration. 21% of all carious defects were found in the maxilla as well as in the mandible.
In addition to the high number of untreated carious lesions, the presence of metal ceramics restorations was significantly higher than other restorations types. Carious lesions are main aetiological factors for endodontic measures, but also ceramic restorations including premature contacts have to be considered as causal factors for pulpal irritations.
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