Properties of athletic mouth protectors and materials.
The properties of a variety of mouth protectors and sheet materials used to fabricate custom mouth protectors were determined in order to recommend limits for a specification. Hardness, water sorption, water solubility, impact absorption, and tear strength were measured, and limits for these properties were suggested.
DENTAL/OROFACIAL TRAUMA IN CONTACT SPORTS AND INTRAORAL MOUTHGUARD PROGRAMMES
Since dental/orofacial injuries were the commonest type of injuries sustained during participation in sports activities in the 1980s, when it was apparent that one third of dental injuries was due to sporting involvement, with the remainder being due to accidents, especially at home, the role of the dental profession in relation to dental/orofacial sports injuries became very important. This has inevitably led to the rapid development of a new branch of dentistry called sports dentistry. In line with the development of sports dentistry the causes of dental/orofacial trauma have been examined and a number of studies on the prevalence and aetiology of sports-related injuries has been conducted. Mouthguards worn during participation in sports activities have been shown to provide the most effective protection against dental/orofacial injuries. Moreover, it has been concluded by a number of scientists that mandatory dental/orofacial and periodontal protection for all athletes involved in sporting activities would have major effects in preventing unnecessary injuries and associated life-long discomfort, as well as reducing the high prosthodontic treatment costs involved. Intraoral mouthguards include: stock, self-adapting, and custom-made. Ideally, the dentist should make a treatment plan for mouthguard fabrication. Subsequent care and maintenance should also be accomplished by the dentist alone. In other words, athletes should not wear mouthguards the physical and technological properties of which cannot offer a quality prevention against injuries to the dental/orofacial system. Only the custom-made mouthguard has proved to be the most effective means in the prevention against injuries to the orofacial system. Athletes consider the custom-made mouthguard pleasant to wear either during training sessions or when competing due to its technological properties and appropriate design. The profession should make efforts to promote the use of mouthguards by informing athletes of the possibilities of active prevention against injuries to dental/oral regions in order to reduce their number.
Microstructure of the solder-casting zone in bridges of dental gold alloys.
The composition and structure were studied in the cast and in the solder of bridges which had failed clinically. Both materials were gold alloys but with different contents of Pt, Ag and Zn. The metallographic investigation revealed defects mostly in the solder, situated in the subsurface layer. SEM studied of the fracture surface revealed large porosites and a structure of dense parallel lines--striations--, indicating that the material had failed from fatigue. The materials in the fractured bridges were identified by micro-probe measurements. It was stated that cast material and solder material used together, were of different composition.