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Biomedical subjects

R J Wilding

Publications and source records attributed to R J Wilding.

29 records · Page 2Linked to original sources
PubMed1988

Tooth wear measurements using a reflex microscope.

The resistance to wear of composite resins is an important feature of their suitability for use as posterior restorative materials. The in vivo clinical evaluation of new materials requires an accurate and reliable method of assessing tooth wear. The purpose of this study was too investigate the possibility of using a new stereometric measuring instrument for this purpose. Tooth wear was experimentally produced on a lead cast. The volume and average depth lost was measured using a reflex microscope. A gravimetric method of wear measurement was used as a control. When the results of both methods were compared it was found that the mean difference in depth of wear measured between the two methods was 10 microns. The reflex microscope appears to be ideally suited to making objective comparisons between the wear characteristics of composite resins.

Humans↗
PubMed1987

Periodontal disease in partial denture wearers--a biological index.

Studies on the adverse effects of partial dentures on the remaining tissues require both a yardstick of measurement to record the level of oral disease, and the use of controls, preferably within the same patient. A method was devised for pooling the individual values related to the level of periodontal disease on abutment and control teeth in partial dentitions. The difference in these combined values was expressed as the Biological Price. This value provided a useful means of evaluating partial denture designs and patient features, in attempting to assess the major contributing factors responsible for the Biological Price levied by the denture. Whilst wearing an acrylic partial denture at night adds to the price paid by the remaining tissues, the mechanical features of the partial denture, and the overall features of the patient and his remaining dentition appear to be insignificant in determining the Biological Price.

Adolescent↗
PubMed1987

The prevalence of temporomandibular joint dysfunction in edentulous non-denture wearing individuals.

This study reports on the prevalence of temporomandibular joint dysfunction in a sample of fifty-one edentulous non-denture wearing individuals. In comparison with other studies using similar criteria, and considering the anomalous mandibular postures observed, this sample of patients appears to have a low prevalence of dysfunction. Loss of vertical occlusal height on its own may not be responsible for the temporomandibular joint dysfunction occasionally seen in denture wearers with reduced vertical height. The possibility that posterior occlusal wear producing incisal interference is an aetiological factor, is discussed.

Adult↗
PubMed1987

The use of panoramic radiographs to measure alveolar bone areas.

The purpose of the study was to determine the accuracy of measurements made of the mandible from panoramic radiographs. A comparison was made between measurements made directly from dry mandibles, and measurements made from panoramic radiographs of the same mandibles. The use of linear proportions reduced the errors of successive radiographic observations but failed to reveal left- and right-side differences. A method was developed to demarcate two areas of the radiograph, one of which was defined by the crest of the residual alveolar ridge and the other independent of the alveolar ridge. Both areas were measured and their proportions calculated for each mandible observed. This proportional value was referred to as the Area Index. The method was applied to panoramic radiographs of individuals with complete dentitions. The inter-observation error of the Area Index was found to be 4.9%. It was concluded that, in selected cases, panoramic radiographs can be used to provide information about resorption of the residual mandibular alveolar bone.

Alveolar Process↗
PubMed1985

A photogrammetric method for monitoring changes in the residual alveolar ridge form.

Resorption of the residual alveolar ridge calls for regular attention to the fitting surface of a denture. In the case of distal extension partial dentures, changes which occur in less than a year may require attention. These changes are apparent, though difficult to measure using radiographic techniques. Stereophotogrammetry is a means of recording and measuring contours of land masses. A short focus non-metric camera was used in this study to produce stereoscopic paired pictures of four casts of the same partial dentition. Additional casts were made 2 and 12 months after a partial denture had been made. A stereophotogrammetric plotting instrument was used to map the alveolar ridge area of each cast. A prescribed area for each map was traced out and the volume above a reference height was calculated. The percentage error between the four columns for the pre-treatment casts was +/- 2%. A 10% loss of ridge volume was observed after wearing a partial denture for 2 months. The same area observed 12 months later revealed an 18% volume reduction. Short range stereophotogrammetry may be applied to study changes in alveolar ridge morphology which may result from wearing a partial denture.

Alveolar Process↗