Search PubMed⌕ Search

Biomedical subjects

A Kingman

Publications and source records attributed to A Kingman.

At least 73 records · Page 4Linked to original sources

Effect of local and parenteral immunization on implantation of Actinomyces viscosus T6 in rats.

Groups of rats immunized in the vicinity of the major salivary glands or immunized intraperitoneally with Actinomyces viscosus T6 and their sham-immunized controls were infected with the homologous bacterium. Significantly higher levels of salivary and serum antibody were induced by intraperitoneal than by salivary gland immunization. There were also significant inverse correlations between the levels of salivary and serum antibody and the levels of implantation of A. viscosus T6. The level of implantation of A. viscosus T6 was significantly lower in the immunized animals than in the controls. However, antibody had limited capacity to inhibit the establishment of this bacterium.

Actinomyces↗

An international collaborative study of laboratory methods for assessing abrasivity to dentin.

An International Collaborative Study was conducted in which one surface profile and two radiotracer methods for assessing abrasivity of dentifrices on human dentin were compared. The study consisted of two phases: an open phase in which participating laboratories used the method they routinely practiced; and a controlled phase in which an expert team for each method performed the abrasion tests using all three methods. Four test pastes of known abrasivity were evaluated by each method. Similar abrasivity values for the test pastes were obtained with the radiotracer methods, whereas the surface profile method produced significantly different values. The precision levels of the radiotracer methods were similar, and both were superior to those obtained by the surface profile method. The time needed to perform the tests by the ADA radiotracer method was significantly less than that needed by the other methods. These findings suggest that the ADA radiotracer method will be useful in assessing abrasivity of dentifrices.

Calcium Carbonate↗

Effects of sequential calcium phosphate-fluoride rinses on dental plaque, staining, fluoride uptake, and caries in rats.

Oral rinses which included (1) an acidic calcium phosphate solution containing 0.7 M Ca, 1.9 M PO4, and saturated with respect to CaHPO4 . 2H2O, and with a pH of 2.0, followed by (2) a 0.52 M fluoride solution, from NaF or SnF2, were provided to rats once daily for seven days. The investigation consisted of two studies: In the first study, the amounts of dental plaque on the tooth surfaces and fluoride concentrations in the outer enamel were assessed seven days after the last treatment; in the second study, the extent of dental caries was evaluated seven weeks after the last treatment. All rinse sequences containing fluoride provided significant caries protection. The acidic calcium phosphate treatment markedly enhanced the ability of the enamel to acquire fluoride without change of surface morphology. Only the rinse sequences that included stannous fluoride showed significant plaque suppression.

Animals↗

A new method for assessing the prevalence of dental fluorosis--the Tooth Surface Index of Fluorosis.

A new index for measuring the prevalence of dental fluorosis, the Tooth Surface Index of Fluorosis (TSIF), was used to assess the condition in the permanent teeth of 807 children, aged 8 to 16, who had resided all their lives in one of seven Illinois communities with an optimal concentration of fluoride in its water or with 2, 3, or 4 times the optimal concentration. Fluorosis was absent in 84.5% of all tooth surfaces examined in the community with optimal fluoride. In contract, only 31.9% of tooth surfaces had no fluorosis in the community with 4-times the optimal fluoride level. In the optimal fluoride area, 79% of facial surfaces of maxillary anterior teeth, which are esthetically conspicuous, had no fluorosis, whereas only 15.8% of these surfaces in the 4-times optimal area were unaffected. The percentages of all tooth surfaces affected by fluorosis characterized by staining, pitting, or both were 1%, 8%, 19%, and 38%, respectively, in communities with 1-, 2-, 3-, and 4- times optimal fluoride. Differences in fluorosis based on maximum score for all tooth surfaces in a child were statistically significant (an extended chi 2 statistic) among all communities. First molars and incisors in children 8 to 10 years old were affected by more fluorosis than were the same teeth in children 13 to 16 years old. These teeth had been erupted for about 5 years longer in the older age group. The difference might result from abrasion or remineralization of these teeth in the older children or from greater consumption of fluoride by the younger children during tooth development.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Prevalence of dental caries and dental fluorosis in areas with optimal and above-optimal water fluoride concentrations.

The prevalence of dental caries and dental fluorosis was assessed among 807 schoolchildren in four areas of Illinois where the respective water supplies contained natural fluoride at concentrations of 1, 2, 3, and 4 times the recommended optimal for the geographic area. Mean caries scores in all three above-optimal fluoride areas were significantly lower than in the optimal area. The prevalence of dental fluorosis was characteristically low in the optimal fluoride area. Substantial increases in fluorosis occurred in the above-optimal fluoride areas, with the condition being most pronounced in the 4-times optimal area.

Adolescent↗

Repeat measurements analysis of dental data.

The statistical analysis of trials in which individuals are evaluated repeatedly at several time points is examined. For the case in which correlations between observations follow a specified pattern, a conservative F test is applied to test for the effects of time and for the interaction between time and treatment groups.

Analysis of Variance↗

A method of utilizing the subjects' initial caries experience to increase efficiency in caries clinical trials.

A problem which often occurs in caries clinical trials is the existence of an imbalance by group in the initial DMFS scores among subjects completing the study. Four methods of incorporating the study subjects' initial caries experience were identified and compared in six recently conducted clinical trials to see which of the methods was the most efficient in making treatment group comparisons of study subjects' caries increment scores. The consistent method of choice was one which utilized an adaptation of Grainger's caries severity index as a stratification factor in a blocking analysis of caries increments. The results suggest that more information regarding future caries exist in knowing where decay is present in the dentition than in knowing the subjects' total DMFS counts.

Adolescent↗

Adequte cohort sizes for caries clinical trials.

Methods of determining cohort sizes were examined to determine their appropriateness for use in multi-group caries clinical trials. The appropriate method to sue depends on the type of trial being planned. It is shown that multiple comparison methods using certain Bonferonni type t-statistics ought to be used in trials in which different levels of frequencies of application of known caries inhibitors are being tested. It is also demonstrated that using the F-test procedure in the determination of cohort sizes can result in unacceptable low sensitivity levels being realized for the comparisons of primary concern. Tables are presented which can be used to determine group sizes needed to achieve specified sensitivity levels for two-groups trials and multi-group trials.

Clinical Trials as Topic↗

An evaluation of Knutson's formula for estimating age-specific DMF teeth.

The present study evaluated a formula suggested by Knutson for obtaining an age-specific estimate of mean DMFT in a population on the basis of the age-specific percentage of individuals with 1 or more DMFT. A total of 149 previously collected age-specific data sets from low-flouride areas in the U.S.A. were used, and the two parameters K and B were estimated using the method of weighted least squares. The analysis showed that the formula could be used with good accuracy for certain restrictions of age (5--11 years) and percentage of individuals with 1 or more DMFT (less than or equal to 70%).

Adolescent↗