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Biomedical subjects

D H Edmunds

Publications and source records attributed to D H Edmunds.

At least 19 recordsLinked to original sources
PubMed1993

An in vitro study into the effect of a bacterial artificial caries system on the enamel adjacent to composite and amalgam restorations.

A microbial artificial caries system was used to produce caries-like lesions adjacent to amalgam and composite restorations. Polarised microscopy allowed measurement of outer and wall lesions depths. Comparison was made of the depths found in relation to the restorative materials, margin finishing procedures (composite group), varnish application (amalgam group) and thermal stressing. It was found that differences were detectable between the different restorative materials and the type of margin finishing procedure used in the composite group. Varnish application and thermal stressing had little effect. Some comparison is made between this microbial technique, other artificial caries techniques, and other methods of assessing marginal leakage.

Adolescent↗
PubMed1990

The production of secondary caries-like lesions on cavity walls and the assessment of microleakage using an in vitro microbial caries system.

The aim of this study was to assess microleakage along restored cavity walls using a new in vitro microbial technique. Extracted human teeth containing cavities restored with a microfine posterior composite were incubated in broth inoculated with a single strain of Streptococcus mutans for 10 days, using a sequential batch culture technique. Each margin of the cavities was finished in one of three ways: butt joint and etching; butt joint and no etching, or; bevel joint and etching. The assessment of microleakage was achieved by examining sections of the teeth histologically using polarized light for the presence or absence of caries-like cavity wall lesions. Outer (surface) lesions were also examined and displayed the characteristic zones of early natural caries lesions. The cavity wall lesions were observed as a translucent zone in 31% of butt and unetched margins, 16% of butt and etched margins, and 5% of bevelled and etched margins.

Acid Etching, Dental↗
PubMed1990

Root canal retained restorations: 1. General considerations and custom-made cast posts and cores.

The first article in this series reviews general considerations relating to the use of root canal retained restorations. The authors discuss factors affecting retention, the arguments for cast versus wrought posts, reinforcement of the tooth, and treatment planning. Clinical procedures for constructing custom-made cast posts and cores, using direct and indirect techniques, are also described. The three subsequent articles will deal with threaded and unthreaded prefabricated post-and-core systems, and root-face attachments for the retention of complete and partial overdentures.

Humans↗
PubMed1990

Root canal retained restorations: 3. Root-face attachments.

It has been common practice for many years to use retained roots to provide support and stability for partial or full dentures. The retention of such overdentures is greatly enhanced if the remaining roots are modified and restored with posts and root-face attachments. The final article in this series on root canal retained restorations classifies and describes some of the root-face attachments currently available, and also describes a number of prefabricated post systems with integral overdenture attachments. Guidelines for clinical and laboratory procedures are given.

Denture Design↗
PubMed1989

Management of anxiety in dental practice in the UK.

A postal questionnaire was sent to a random sample of dentists in the United Kingdom. The response rate was 59.9%. Anxiety was reported as a significant problem by 66% of dentists and information was gained regarding the techniques used to manage this anxiety. 'Patient management' and general anaesthesia were the techniques most commonly employed. The frequency of usage of intravenous and inhalational sedation varied according to the age of the patient. Only 55.3% of dentists in general practice had any training in a sedative technique.

Anesthesia, Dental↗
PubMed1989

The sealing ability of injection-moulded thermoplasticized gutta-percha.

The root canals of 120 single rooted teeth were prepared with files and then divided randomly into twelve subgroups. Four operators each filled three of these subgroups, one group with laterally condensed gutta-percha, one group with thermoplasticized gutta-percha with sealer and one group with thermoplasticized gutta-percha without sealer. The fillings were assessed radiographically and a dye penetration test was used to investigate the leakage. The lowest leakage values were found in those canals filled with laterally condensed gutta-percha. The sealing ability of thermoplasticized gutta-percha was enhanced by the use of a sealer. There was greater variation between operators in those groups where thermoplasticized gutta-percha was used.

Dental Leakage↗
PubMed1989

Root resorption in autotransplanted maxillary canine teeth.

The results of the endodontic management of root resorption in 77 transplanted teeth are described. Apical bony radiolucency healed in 75 per cent of cases but the prognosis for root resorption was poorer; in only 34 per cent of cases was the resorption arrested. Various factors which might have influenced the outcome of treatment are discussed.

Adolescent↗
PubMed1989

Sealing ability of amalgam used as a retrograde root filling in endodontic surgery.

A dye penetration technique was used to investigate the sealing ability of amalgam retrograde root fillings in vitro. A factorial design was employed to determine the effect of amalgam fillings of 1, 2 and 4 mm in length with and without prior filling of the canals with gutta-percha. The results were compared with a group of teeth filled with laterally condensed gutta-percha alone and another with laterally condensed gutta-percha plus root resection but with no retrograde filling. It was concluded that increasing the length of the amalgam filling did not improve the seal, that prior filling of the canal did not improve the seal, that retrograde root fillings were no worse than laterally condensed gutta-percha alone and that root resection of teeth filled with laterally condensed gutta-percha without retrograde filling was no worse than those filled with laterally condensed gutta-percha without root resection or retrograde root filling.

Dental Amalgam↗
PubMed1989

Sealing ability of materials used as retrograde root fillings in endodontic surgery.

The sealing ability of retrograde root fillings of amalgam plus cavity varnish, EBA cement, glass ionomer cement, light-cured composite resin, dentine bonding agent, and light-cured composite resin plus dentine bonding agent were compared with laterally condensed conventional root fillings. A dye penetration technique was used to assess microleakage and it was concluded that none of the materials produced a perfect seal but that glass ionomer cement, light-cured composite resin, light-cured composite resin plus dentine bonding agent and dentine bonding agent alone produced better seals than conventional laterally condensed gutta-percha, amalgam plus cavity varnish and EBA cement.

Composite Resins↗
PubMed1988

Suitability of human, bovine, equine, and ovine tooth enamel for studies of artificial bacterial carious lesions.

The progress of artificial caries-like lesions created in human, bovine, equine, and ovine enamel has been studied. Lesions were produced by exposure to an acid gel system or by 5-day exposure to a sequential batch culture technique using Streptococcus mutans NCTC 10832. Longitudinal ground sections were prepared. The lesions were of similar appearance in all species when examined in polarized light. The depth in human enamel was approximately half that in the animal species. Microradiography confirmed subsurface demineralization in all four species. Similar depth ratios were seen in the scanning electron microscope, but there were structural differences between lesions in human and animal teeth. Lesions in bovine teeth were more like those in human, but lesions in equine and ovine teeth were markedly different. Substitution of these animal enamels for human enamel in caries experiments demands that these differences be taken into account. Scanning electron microscopy is capable of resolving features in artificial caries lesions which cannot be differentiated by polarized light techniques. The latter will demonstrate generalized mineral loss, but scanning electron microscopy is required to characterize the sites of mineral loss.

Adult↗
PubMed1984

Inhalation sedation with 25% nitrous oxide. Report of a field trial.

A field trial is reported of the use of a fixed concentration of 25% nitrous oxide to produce sedation in anxious dental patients. Three hundred and ninety-four patients were treated on 1005 occasions. Ninety-nine per cent of patients were treated successfully without any incidence of loss of consciousness, including 47 children who were treated on 88 occasions.

Adolescent↗