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Biomedical subjects

R C Paterson

Publications and source records attributed to R C Paterson.

At least 19 recordsLinked to original sources
PubMed1998

Management of fissure caries in the community dental services using sealant restorations: a field trial.

Field trial data two years after the placement of 278 composite or laminate (sandwich) composite sealant restorations by 14 Community Dental Officers, in patients ranging in age from 6 to 16 years, in the West of Scotland, is reported. No restorations were lost and in 76% of the restored teeth, fissure sealant was partly retained. The most common sites of loss of sealant were from the buccal fissures of mandibular molars and from the surface of the restoration. Only 5% of the treated teeth showed complete loss of fissure sealant and the authors considered that after 2 years, 90% of restorations were adequate or only required the simple addition of further fissure sealant.

Adolescent↗
PubMed1997

Prediction of the extent of caries in pit and fissure lesions in a field trial in the west of Scotland.

A field trial is in progress in which 14 community clinical dental officers and 19 general dental practitioners were asked to record the actual extent of fissure lesions and how this compared with the cavity size they expected. Participating operators worked under their normal conditions of daily practice. Forty-eight to fifty-seven percent of 644 prepared cavities were of the expected size upon investigation, depending on the diagnostic technique used. Greater accuracy was achieved among the smaller cavities (58-75% as expected) than with the larger (52-69% larger than expected). More difficulty with cavity size prediction occurred with the lower right first molar than with the other first molar teeth and with both mandibular second molars compared to the maxillary molars. Comparisons between the accuracy of cavity size prediction achieved using a visual inspection in combination with the probe and a visual inspection alone showed no significant difference. Under the conditions of this field trial, considerable difficulties were experienced in predicting cavity size accurately.

Adolescent↗
PubMed1997

Fissure caries diagnosis and resulting treatment decisions by clinical community dental officers and general dental practitioners.

In this in vitro study, 12 General Dental Practitioners and 13 Clinical Community Dental Officers examined the occlusal, buccal and palatal pits and fissures of 35 extracted molar teeth. They were asked to make a management/treatment decision, on the basis of their diagnosis of caries, whether each tooth should be left untreated, fissure sealed or investigated. After all the management/treatment decisions had been made, the teeth were serially sectioned perpendicular to the occlusal surface and examined for the presence of caries in dentine. It was impossible to demonstrate differences in the management/treatment decisions and the diagnosis of caries made by the two groups. No significant difference in sensitivity or specificity could be detected between operators diagnosing by visual inspection alone and those using visual inspection in combination with a tactile method. The use of radiographs did not significantly improve the validity of the diagnosis or management of fissure caries.

Community Dentistry↗
PubMed1995

Initial stages in the development of valid criteria for the replacement of amalgam restorations.

OBJECTIVES: Replacement amalgam restorations account for the largest single cost in the General Dental Services in Scotland. There is little practical advice available to practitioners on the maintenance and replacement of amalgam restorations. A distance learning package is being prepared for distribution to general dental practitioners in Scotland and this paper describes the initial stages in the development of the policy statements for the proposed package. METHODS: In the first stage proposals are being developed by a panel of dental academics using a modified Delphi technique. This technique is designed to produce a consensus view. Seventeen statements have been set out by the expert group. RESULTS AND CONCLUSIONS: While agreement was rapidly reached that 'ditching' of amalgam restoration margins did not justify their replacement and that repair was preferable to total replacement, some difficulty was experienced in arriving at a consensus view on the correct management of 'white spot' lesions at restoration margins and dentinal staining adjacent to amalgam restorations. The next stage in the development will be to present these statements to a selected panel of general dental practitioners and to develop their consensus view of the proposals, again using the Delphi technique.

Delphi Technique↗
PubMed1994

Clinical assessment of glass ionomer/composite resin sealant restorations in permanent teeth: results of a field trial after 1 year.

A large field trial is in progress in the Community Dental Service in the West of Scotland to evaluate the effectiveness of glass ionomer/composite resin sealant restorations in the treatment of fissure caries. 128 of the restorations were placed by 14 community dental officers. After 1 year, 98 restorations were reviewed. All of the glass ionomer restorations were retained but only 12 of the sealants were completely intact. Sealant was retained over only 32% of the restorations and in 13%, 48% and 69% of adjacent buccal, occlusal and palatal fissures, respectively.

Adolescent↗
PubMed1994

Pulp response to a novel adhesive calcium hydroxide based cement.

This study compares pulp responses to 3 formulations of calcium hydroxide, namely: a) An experimental adhesive calcium hydroxide cement containing polyacrylic acid, b) Dycal (L.D> Caulk Co, Milford, Delaware) Batch Nos 176970/176990, c) "Analar" calcium hydroxide mixed with sterile distilled water. After 28 days dentine bridges were present in 77% of teeth capped with the test material, 64% of teeth treated with Dycal and in 62% of teeth capped with calcium hydroxide and water. Inflammatory infiltrates were observed in a number of teeth remote from the bridges. Bacteria were detected in these specimens. Exposed rat molar pulp responses to an experimental adhesive calcium hydroxide cement were similar to to those observed with 2 other calcium hydroxide formulations.

Animals↗
PubMed1993

Development and harmonisation of the norms and parameters in biological testing protocols designed for root canal sealing materials within the European Community.

The EC has mounted the BIOMED 1 as a specific programme to facilitate cooperative research programmes in identified areas of interest throughout Europe. They have recently announced support under this programme for a joint initiative designed to evaluate in vitro and in vivo methods of biological testing of root canal sealing materials. This proposal was prepared by a group of research workers in the field. It provides a summary of the current suggested protocols for the biological testing of dental materials and then provides a detailed protocol of the studies to be carried out in the joint programme which commenced in January 1993. The authors are publishing the proposal to invite comments from colleagues and interested parties.

Animals↗
PubMed1992

Pulp responses to two strains of bacteria isolated from human carious dentine (L. plantarum) (NCTC 1406) and S. mutans (NCTC 10919).

A series of studies has been conducted in which monoinfected gnotobiotic rats were used to study the responses of the dental pulp to micro-organisms isolated from carious lesions in dentine. In this study pulp responses to L. plantarum (formerly odontolyticus) (NCTC 1406) in pure culture and in combination with S. mutans (NCTC 10919) are reported. The incidence of inflammation/necrosis/dentine bridge formation observed in animals monoinfected with L. plantarum was similar to that reported in previous germ-free studies. There was a greater incidence of dentine bridge formation in rats monoinfected with L. plantarum compared with those monoinfected with S. mutans. When the two organisms were combined, periapical inflammation was observed in 14% of the teeth examined after 28 days, but there was no significant difference in the incidence of dentine bridge formation. Considerable variation in the density of staining of the two microorganisms in histological sections was observed.

Animals↗
PubMed1992

Pulp response to, and cariogenicity of, a further strain of Streptococcus mutans (NCTC 10832).

The pulpal response to and cariogenicity of a third strain of Streptococcus mutans, namely S. mutans (NCTC 10832), was studied in monoinfected gnotobiotic rats of the Fischer strain using the techniques described previously by the present authors. Unlike S. mutans (NCTC 10449 and 10919), S. mutans (NCTC 10832) was associated with the presence of inflammatory cell infiltrates in the coronal pulp of a small number of teeth and extensive periapical inflammation 28 days after the creation of untreated pulpal exposures. S. mutans (NCTC 10832) was associated with the presence of extensive pulpal necrosis and reduced dentine bridge formation. These changes were similar to those noted with the other two strains of S. mutans. S. mutans (NCTC 10832) was non-cariogenic in monoinfected gnotobiotic rats of the Fischer strain.

Animals↗
PubMed1992

Continuing education for general dental practitioners using a printed distance learning programme.

This paper describes the development of a printed distance learning programme by a coordinated team approach. The programme has two components, a resource book and three patient management problem leaflets or challenges and is designed to update general dental practitioners on the management of fissure caries. It includes strategies to meet the educational needs of three groups of general dental practitioners with different educational requirements. It is concluded that the approach described meets the CRISIS criteria for effective continuing education and offers a useful approach to distance learning in dentistry.

Education, Dental, Continuing↗
PubMed1991

A review of current proprietary bonding systems.

This is the third of a series of articles reviewing the current knowledge on bonding systems. In the two previous papers the nature of the dentine smear layer and the preparation of the dentine surface for bonding were considered. This article reviews the current knowledge of the mechanisms of dentine bonding and presents a summary of the composition and mode of action of some of the more recent proprietary bonding systems.

Dental Bonding↗
PubMed1990

Reported use of sealant restorations in a group of general practitioners in the west of Scotland.

A postal/telephone survey of 452 general practitioners working in the Greater Glasgow and Lanarkshire Health Board areas was carried out between March and June, 1989. The aim was to investigate the use of sealant restorations under section 6 of the National Health Service fee scale for general dental practitioners. Section 6 itemizes fees for fissure sealant, glass-ionomer cement plus sealant, composite resin plus sealant and the laminate restoration. A response rate of 83% was obtained. Eighty-one per cent of the respondents were placing sealant restorations, but less than half were using the laminate or sandwich technique. A wide variety of materials and curing lights were employed. Enamel etching times varied considerably and rubber dam was seldom used. Eighty-nine per cent indicated that they would welcome illustrated fact sheets demonstrating the use of sealant restorations.

Acid Etching, Dental↗
PubMed1989

Pulp response to, and cariogenicity of, a strain of Streptococcus mutans.

Gnotobiotic rats mono-infected with Streptococcus mutans (NCTC 10919) were maintained on a high sucrose diet in an isolator. When they were 8 weeks old the pulps of their maxillary first and second molars were mechanically exposed and left open to the oral environment. The rats were sacrificed in groups after 7 and 28 days. Thirty-seven teeth were available for study in the 7-day group, and 30 teeth in the 28-day group. The test S. mutans was non-cariogenic. After 7 days, necrosis of the superficial layers of the pulp was noted; however, after 28 days pulpal necrosis was much more extensive and calcific repair was observed in only one-third of the teeth examined. The microorganism did not provoke inflammation in the pulp or periapical tissues. This is the second strain of S. mutans tested in this manner. These results are very similar to those reported previously for S. mutans (NCTC 10449) and strengthens the view that organisms of the S. mutans group have a low pathogenicity for the pulp.

Animals↗