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Biomedical subjects

R C Paterson

Publications and source records attributed to R C Paterson.

At least 37 records · Page 2Linked to original sources
PubMed1988

Preliminary investigation into the validity of dentists' decisions to restore occlusal surfaces of permanent teeth.

This study investigates the validity of the treatment decisions made by 10 hospital dentists, who examined the fissures of extracted teeth using a visual-only technique. The study shows that 8 of the 10 dentists were more likely to leave carious teeth unrestored than unnecessarily treat sound teeth. The authors suggest that this system of diagnosing occlusal caries is a satisfactory one in terms of its sensitivity and specificity.

Dental Caries↗
PubMed1987

Differential regulation of gamma-crystallin genes during mouse lens development.

Using gene-specific probes derived from four mouse gamma-crystallin cDNAs, we have examined the regulation of different members of the mouse gamma-crystallin gene family during lens development. Our analysis revealed that, while the different gamma-crystallin genes appear to be coordinately activated during embryogenesis, the steady-state levels of their corresponding transcripts are differentially regulated, resulting in variations in the relative abundance of individual species at different stages of development. This complex pattern of gene regulation presumably accounts for one of the mechanisms determining the spatial distribution of different gamma-crystallins within the lens.

Aging↗
PubMed1987

Pulp response to Streptococcus mutans.

The maxillary molar pulps of germ-free rats were mechanically exposed, and suspensions of a strain of freshly grown Streptococcus mutans were applied to the pulp wounds. The pulps were left open to the oral environment, and the animals were maintained in the isolator until they were killed in groups after 2, 7, and 28 days. After 2 days there was little evidence of any pulp response. In the 7-day group early pulp necrosis was present. No evidence of inflammatory infiltration was detected in either the 2- or 7-day animals. After 28 days there was extensive pulp necrosis in many specimens. Dentine bridges were present in fewer than one fourth of the teeth.

Animals↗
PubMed1987

Pulp response to and cariogenicity of Lactobacillus casei in monoinfected gnotobiotic rats.

The maxillary molar pulps of germ-free rats were mechanically exposed and suspensions of a strain of freshly grown Lactobacillus casei were applied to the pulp wounds. The pulps were left open to the oral environment, and the animals were maintained within the isolator until death. In the majority of teeth, pulp necrosis was evident and apical inflammation was present in 40% of the specimens. The remaining monoinfected animals were bred and the litters were placed on a 46% sucrose diet to determine the cariogenicity of the test strain of L. casei in the mandibular molars. The organism proved to be noncariogenic. The effects of mechanical exposure of the maxillary molars in these animals were similar to those observed in the direct-inoculation study, with the exception of a reduced incidence of apical inflammation.

Animals↗
PubMed1987

Bacterial contamination as a factor influencing the toxicity of materials to the exposed dental pulp.

Three materials, which had been previously found to be toxic when applied as pulp-capping agents in conventional rat molar pulps, were retested in germ-free rats. All produced much more favorable responses in the pulp, with a lack of inflammation and the presence of dentine bridges in the majority of teeth. It appears that much of the pulp damage previously attributed to the chemical toxicity of materials may be caused by the presence of bacteria. The design of studies intended to evaluate the response of the pulp to materials should include staining techniques that will detect the presence of bacteria on the floors of test cavities.

Aluminum Hydroxide↗
PubMed1983

Drill and fill.

Explore the source record for details and available documents.

Dental Restoration, Permanent↗
PubMed1983

Bacterial contamination and the "toxicity" of materials to the exposed pulp.

The role of bacterial contamination in the toxicity to the pulp of a number of metallic salts was investigated. These had been tested as pulp-capping agents in previous studies involving 228 exposed rat molars. Material from the previous investigations was stained to demonstrate bacteria. This revealed bacteria in necrotic pulp tissue and/or the cavity-restoration interface in approximately 60% of the specimens. The presence of bacteria appeared to be related to pulpal inflammation, necrosis, and failure of calcific repair.

Animals↗