Effect of storage media on subsequent water loss and regain by human and bovine dentine and on mechanical properties of human dentine in vitro.

This study was designed to determine whether storage media and time affect any changes in water loss with dehydration of dentine. The effect of storage of prepared bars was also compared with storage of whole teeth. Prepared bovine dentine bars were stored for 3 days or 12 weeks in deionized water, phosphate-buffered saline or neutral-buffered formalin and whole teeth were stored in neutral-buffered formalin for 12 weeks before the preparation of dentine bars.

The effects of dehydration and rehydration on some mechanical properties of human dentine.

This study was designed to investigate the effect of dehydration and rehydration on the brittleness and toughness of human dentine. Tensile and three-point bend tests were carried out on hydrated, dehydrated and rehydrated dentine bars, sectioned from sound extracted, human third molar teeth. The stress, strain and fracture energy (toughness) were calculated and the results were analysed using ANOVA and Duncan's multiple range test at p = 0.

Simulation models for teaching endodontic surgical procedures.

Models which simulate oral conditions pertaining to endodontic surgical procedures are most suitable if they contain natural teeth and have hard and soft tissues which handle realistically. In addition, the model should possess radiological characteristics similar to bone. A simple custom-built model which fulfils these requirements is described.

Dentinal tubules at the root ends of apicected teeth: a scanning electron microscopic study.

Two groups of teeth, one of which contained teeth of known age, were examined by scanning electron microscopy to ascertain the presence of a potential pathway for leakage at the root ends of apicected teeth. At a point approximately 3 mm from the apex, a level chosen as being typical for apicectomy, and half-way between the root canal and the dentine-cementum junction, there were found to be, on average, 27,000 tubules per mm2. Older teeth also displayed large numbers of tubules.

Radiographic interpretation of endodontic lesions--a shadow of reality.

The radiographic interpretation of pathological lesions which are endodontic in origin is relatively imprecise as so many variables are involved. Even the presence or absence of a lesion cannot be determined with accuracy and there is little agreement on the criteria which should be applied. Strict attention to the technique of exposing, processing and viewing radiographs is necessary if the information to be gained is to be optimal.

Porous metal coatings for resin-bonding systems.

Two porous coating systems produced surfaces 20 to 30 microns thick, capable of engaging the unfilled component of composite during bonding procedures. A technique is suggested whereby the thickness of porous coating may be compensated by die spacing. The film thickness of the cement tested would be unlikely to affect the fit of any such prosthesis.