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S K Pountney

Publications and source records attributed to S K Pountney.

3 recordsLinked to original sources

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

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