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Biomedical subjects

M E Curzon

Publications and source records attributed to M E Curzon.

At least 73 records · Page 4Linked to original sources
PubMed1988

Site-specific differences in human dental plaque pH after sucrose rinsing.

The object was to find out whether site-specific variations of pH might correlate with those of oral clearance as indicated by past studies using fluoride, sucrose and glucose as markers. Eleven subjects with 24 h growth of dental plaque rinsed the mouth with a 10% solution of sucrose. The pH of plaque, harvested from the labial or buccal cervical and approximal regions of certain teeth or groups of teeth, was then measured. The results confirmed previous reports that plaque pH varies from site to site in the mouth; the pattern observed was similar in each of the subjects. In the anterior part of the mouth, concentrations of hydrogen ion were invariably higher in plaque from the upper than from the lower surfaces of the teeth. The reverse pattern was found in the posterior part. This site-specific pattern was similar to that of oral clearance, as indicated by comparison with known values for glucose concentrations, a finding consistent with the view that site-specific pattern of plaque pH may reflect or at least be influenced by such differential clearance patterns.

Adolescent↗
PubMed1987

Inhibitory effect of barium on human caries prevalence.

The aim of this investigation was to determine if barium in drinking water, in combination with fluoride, has an effect on caries prevalence in a human population. Children, aged 12-14 yr, were selected from two towns which had a similar socioeconomic and racial balance but one had a barium concentration of 8.0-10.0 ppm in its drinking water and the other a level which was less than 0.03 ppm. The caries prevalence, as mean DMFS, was significantly lower in the high barium town (2.76 +/- 0.82) than in the low barium town (5.14 +/- 0.65). The difference in mottling scores between the two towns was not significant (P = 0.44, chi-square test). This difference in mean DMFS between the high and low barium communities could not be explained by an effect of other covariate factors.

Adolescent↗
PubMed1986

Dental caries prevalence in Texas schoolchildren using water supplies with high and low lithium and fluoride.

The effect of lithium (Li) in drinking water on caries prevalence in seven Texas towns was investigated. Children (life-long residents) aged 12-14 years were examined for caries prevalence, as DMFS, in towns with drinking water Li concentrations ranging from 0.0 to 165 micrograms/L and fluoride (F) concentrations ranging from 0.20 to 1.94 mg/L. A significant negative relationship was found between F in drinking water and DMFS. When corrected for the F contribution, Li in water supplies showed a positive correlation with DMFS.

Adolescent↗
PubMed1985

The relation between caries prevalence and strontium concentrations in drinking water, plaque, and surface enamel.

Samples of plaque and surface enamel were collected from 80 boys aged 14 years living in five communities in Ohio (USA). Mean (+/- SE) strontium concentrations in plaque were 1.43 +/- 0.18 micrograms/g (wet) and 12.34 +/- 1.63 micrograms/g (dry). For surface enamel, the mean concentration was 421 +/- 31 micrograms Sr/g. Concentrations of strontium in both plaque and enamel were significantly related to strontium levels in the drinking water. Caries prevalence as DMFS was inversely related to strontium levels in water, plaque, and enamel.

Adolescent↗
PubMed1984

Strontium concentrations in whole human saliva.

Whole unstimulated saliva samples were collected from 91 male, 14-yr-old school children in seven Wisconsin (U.S.A.) communities with varying strontium levels in their drinking water (0.22-33.6 mg/l). There was a mean concentration of 0.035 mg/l (+/- 0.001 SEM) with a range of 0.02 to 2.93 mg/l of strontium. Saliva-strontium concentrations were weakly associated with drinking-water concentrations. A negative relationship between saliva-strontium concentrations and caries prevalence was found. Strontium concentrations in saliva were related to time of ingestion of the element and levels of strontium as high as 15 mg/l occurred in saliva within 1 hr of ingesting 30 mg strontium as a single dose.

Adolescent↗
PubMed1984

Effects of fluoride, lithium, and strontium on intracellular polysaccharide accumulation in S. mutans and A. viscosus.

Fluoride (5 mg/l) consistently depressed the accumulation of intracellular iodophilic polysaccharides (IPS) in Streptococcus mutans strains BHT, FA-1, and GS-5 by over 90% and in Actinomyces viscosus strain RC-45 by over 50%. There was little further reduction in IPS content when fluoride was increased from 5 to 100 mg/l. Lithium (0 to 1 mg/l) neither enhanced nor inhibited IPS accumulation, nor did it modify the inhibitory effects of fluoride in three of the four strains tested. Strontium (0 to 100 mg/l) did not alter IPS accumulation in S. mutans GS-5 but decreased accumulation (less than 10%) in S. mutans FA-1 and BHT and significantly enhanced IPS accumulation in A. viscosus RC-45. Analysis of variance indicated no statistically significant interactions between fluoride and strontium, fluoride and lithium, or strontium and lithium.

Actinomyces↗
PubMed1983

Combined effect of trace elements and fluoride on caries: changes over ten years in northwest Ohio (U.S.A.).

Dental caries examinations were carried out in an area of low caries prevalence, ascribed to a combined effect of fluoride and other trace elements. Repeat examinations in 1978 on lifelong resident children aged from 12 to 14 yr showed caries distribution patterns to be essentially the same as those found in a previous study in 1968. Some changes in DMFS scores had occurred, which were associated with changes in the strontium content of the drinking water; low caries levels were significantly associated with high strontium concentrations.

Adolescent↗
PubMed1982

An experimental study of lithium and dental caries in the rat.

Lithium chloride, given via the drinking water, was tested for its effect on dental caries. In a preliminary experiment lithium at concentrations of 0, 5, 20, 40, 60, 125 and 250 microgram/l showed a significant dose-related effect by ANOVA with the lowest smooth-surface scores at 20 microgram Li. Lithium was also used at 20 microgram/l with and without fluoride at 5, 10 and 20 mg/l. No greater effect on caries was seen of the lithium-fluoride combination than fluoride alone. Using 0, 5, 20 and 40 microgram Li/l, and larger groups of rats, a trend for lower caries was seen but the variance of the data was too large to be statistically significant. Despite a number of epidemiologic studies associating low caries prevalence with lithium, animal model research has not demonstrated a clear reduction in caries due to lithium added to the drinking water.

Animals↗