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Biomedical subjects

E C Combe

Publications and source records attributed to E C Combe.

At least 19 recordsLinked to original sources
PubMed1992

Acoustic evaluation of earmoulds in situ: a comparison of impression and earmould materials.

Laboratory research has been carried out on the accuracy of both ear impression and earmould materials. The present work was undertaken to assess such materials in vivo. An objective clinical method of earmould evaluation was developed, based on estimation of the attenuation in the acoustic feedback path. The method was used to assess the acoustic performance of earmoulds made from three earmould materials of different texture, when prepared from two different impression materials. It was shown that the choice of impression material made a significant difference to earmould performance. For greatest accuracy, addition cured silicone impression materials are recommended.

Adolescent↗
PubMed1991

Tin oxide coating of aluminous porcelain by reactive ion plating.

Alumina reinforced dental porcelain has been coated directly with tin oxide by reactive ion plating. Samples were prepared at different distances from the tin source in the ion plating rig. Tensile bond strengths of treated and untreated porcelain discs to a commercially available phosphate-methacrylate based dental cement were determined. Bond strengths of certain coated samples were found to be in excess of the cohesive strength of the porcelain substrates (greater than 7.8 MPa), whereas untreated porcelain achieved an average bond strength of only 3.4 MPa. The microstructures of coatings produced under conditions similar to those which yielded the maximum bond strength were examined in a scanning electron microscope and were found to be approximately 0.5 microns thick. It is believed that ion plating has great potential for rendering inert ceramic surfaces capable of direct bonding to dental cements.

Adhesives↗
PubMed1991

Factors influencing the efficacy of light cured materials for earmoulds.

This work was undertaken to investigate two systems for producing light-cured earmoulds, in order to evaluate the factors which influence the efficacy of such procedures. It was shown that there were variations in light intensity in the light boxes, and that the depth and age of gel in which curing takes place was important. Degree of cure of the materials was assessed by hardness measurements for hard materials and resistance to tearing for hard materials. Light-cured technology has great potential for the rapid production of earmoulds.

Equipment Design↗
PubMed1979

Periodontal dressing materials.

A detailed review of periodontal dressings is presented, covering physical, chemical and biological aspects. Areas requiring further research are outlined, particularly in the physico-chemical sphere; and some contra-indications to particular substances are described. It is concluded that there is a definite place for dressings, but that more knowledge is required before optimal properties can be developed.

Bacteria↗
PubMed1977

Factors influencing the retention of dowels.

A technique for assessing the axial retention of dowels has been developed. This method uses whalebone instead of extracted teeth. Threaded dowels appear to have better resistance to axial displacement than other types. Resistance of threaded dowels to torsional forces can be significantly improved by a rotation lock technique.

Adhesives↗