Biomedical subjects
Publications and source records attributed to R C Paterson.
A number of systems for the biological testing of dental materials have been suggested. This paper presents a critical review of the protocols suggested in the ISO standards for the initial and secondary biological testing of root canal sealing materials.
A number of systems for the biological testing of dental materials have been suggested. This paper reviews the protocols suggested in the ISO standards for the in-use or 'usage' tests for root canal sealing materials.
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.
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.
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.
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.
A study is described in which six metallic compounds identified in a previous pilot experiment were tested as pulp-capping agents using the exposed rat molar. Barium sulfate, calcium carbonate, cupric oxide, ferric oxide, and heavy magnesium oxide gave poor results. Stannic oxide gave more favorable results and is being studied further.
A pilot study is described in which the exposed pulps of molar teeth of normal laboratory rats were capped with various metallic compounds in general medical usage. There appeared to be no relationship between the response obtained and the pH of the compounds studied. Aluminum powder, aluminum hydroxide, Aludrox, aluminum oxide, light magnesium oxide, magnesium hydroxide, and titanium dioxide gave poor results. Barium sulfate, calcium carbonate, cupric oxide, ferric oxide, heavy magnesium oxide, and stannic oxide merited more detailed study.
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