K.W. Stephen

Effect of Oral Care Habits on Caries in Adolescents

Data on toothbrushing habits were collected during a 3-year caries clinical trial of sodium monofluorophosphate toothpastes in Lanarkshire, Scotland, involving 3,005 schoolchildren of mean age 12.5 years at baseline. Stated normal brushing frequency and oral rinsing method after brushing were recorded. Half the panel indicated they rinsed their mouths after toothbrushing using a beaker. The proportion of the panel brushing once per day or more increased during the trial. Differences in oral habits were observed between the sexes, with 42% of girls and 52% of boys being non-beaker rinsers and 73% of girls, but only 44% of boys, brushing their teeth at least twice per day. Twice-a-day brushers had a consistently lower caries increment than less frequent brushers. This was also seen in the baseline prevalence data, but did not account for all incremental differences noted. Subjects using beakers had consistently higher increments than non-beaker rinsers. Again, this difference could not be explained by variations in baseline prevalence. Differences in the caries increment were also observed between boys and girls, these appearing to be linked both to the cumulative effect of male/female habit variations plus a difference in the baseline caries prevalence. A dose response to the three fluoride levels, i.e 1,000, 1,500, and 2,500 ppm F, was seen for the different habit combinations which again could not be explained by differences in the baseline caries prevalence.

Total tooth loss and prevalent cardiovascular disease in men and women: Possible roles of citrus fruit consumption, vitamin C, and inflammatory and thrombotic variables

BACKGROUND AND OBJECTIVE Tooth loss has been associated with cardiovascular disease (CVD), but the mechanisms are unclear. We evaluated the association of total tooth loss with prevalent CVD in men and women; as well as with citrus fruit consumption, plasma vitamin C, and inflammatory and thrombotic variables. METHODS We used an age-and sex-stratified population survey, of men and women aged 25-74 years, in North Glasgow. RESULTS Thirty-eight percent of women and 29% of men were edentulous. Total tooth loss was associated with prevalent CVD in both sexes. After adjustment for major potential confounders (age, sex, smoking, and social class), the odds ratio (95% CI) for prevalent CVD was 1.55 (1.13, 2.13) in the edentulous. Total tooth loss was also associated with low citrus fruit consumption and low plasma vitamin C levels, increased plasma C-reactive protein in men, and with increased plasma interleukin-6, fibrinogen, and factor VIII levels in women. CONCLUSION Prevalent CVD is associated with total tooth loss. Possible mechanisms include low intake of citrus fruit, and hence, low plasma vitamin C levels, and a predisposition to low-grade inflammation and thrombosis. It may be prudent to ensure adequate vitamin C intake in people with no teeth.

Effect of Mouthrinsing after Toothbrushing with a Fluoride Dentifrice on Human Salivary Fluoride Levels

In a recent clinical trial of sodium monofluorophosphate dentifrices, oral rinsing habits were found to influence dental caries. Thus an oral fluoride clearance study has been undertaken which was designed to test a possible mechanism for the observed effects. Eight subjects brushed with one of the trial dentifrices and then rinsed using 1 of 8 procedures of varying thoroughness. The salivary fluoride concentration measured 5 min after dentifrice application decreased significantly with increasing rinse volume, rinse duration, and rinse frequency (p less than 0.01, analysis of variance). The area under the clearance curve determined over a further 3 h was significantly higher (300%; p less than 0.01) following use of the least thorough rinsing procedure (5 ml x 2 s once) as compared with the corresponding area under the clearance curve following the most thorough procedure (20 ml x 10 s twice). These findings indicate that rinsing habits may play an important role in the oral retention of fluoride from dentifrices which may, in turn, affect their clinical efficacy.

Effect of Fluoride Concentration on Remineralization of Carious Enamel an in vitro pH-Cycling Study

An in vitro pH-cycling experiment was carried out to investigate the effect of fluoride concentration on enamel demineralization and remineralization. Artificial caries lesions were formed in an acid-buffered solution and subjected daily to a 3-hour acid attack, a 5-min immersion in the test NaF solution (0, 1, 250, 500, 1,000, 1,750 and 2,500 ppm F), and to 21 h in an artificial saliva. Changes in mineral content were assessed weekly for 5 weeks using microradiography/microdensitometry. The lesions in the control group (0 ppm F) and the 1-ppm F group demineralized. Remineralization was significantly higher in the 500-ppm F group compared to the 250-ppm F group. However, higher fluoride concentrations did not produce any further significant increase in remineralization. Laminations were apparent in lesions subjected to the 250- and 500-ppm F solutions.

Prevalence of dental fluorosis in children from non-water-fluoridated Halmstad, Sweden: fluoride toothpaste use in infancy

Objectives. To determine the prevalence and severity of dental fluorosis in children aged 7–9 years from non-water-fluoridated Halmstad, Sweden, and to relate the results to their reported fluoride exposure history during infancy. Material and Methods. In Spring 2002, a questionnaire distributed to a cluster random sample of 1039 parents enquired into their childs early oral health behaviors and included a “photographic toothpaste menu”. The permanent upper anterior teeth (13–23) were examined clinically (+10% repeats) using a modified Thylstrup-Fejerskov Index. Results. Complete data were available for 53% (n=548) of the sampled children. The prevalence of fluorosis at any level was 49% (95% CI: 45–54%), and of fluorosis with esthetic concern (TF score ≥3) 4% (95% CI: 3–6%). Based on repeat observations, reliability was good (kappa=0.82). There was no statistically significant increased risk of dental fluorosis prevalence associated with any of the fluoride exposure risk factors examined, including reported usage of (1000 ppm) fluoride toothpaste from time of first deciduous tooth eruption. Conclusions. While there were low levels of dental fluorosis of esthetic concern, half the children had some degree of dental fluorosis. The prevalence of dental fluorosis was not explained by the risk factors, including fluoride toothpaste usage as explored in this study.

Comparison of the Plaque Microflora from Natural and Appliance-Borne Enamel Surfaces

Human enamel sections and slabs, mounted on a mandibular removable appliance, were worn by 5 adult subjects for a 1-week period. Plaque was allowed to accumulate on the in situ test sites and on the adjacent natural dentition. At the end of the experimental period, the plaque microflora associated with (1) the enamel sections, (2) the enamel slabs, and (3) the acrylic base of the appliance test site was compared with that obtained from lingual and interproximal areas of the lower molar teeth. In addition, the acid anion and pH profiles of plaque obtained from both the exogenous and natural tooth surfaces were also determined. Although some quantitative differences were found between the proportions of isolates obtained from the different enamel surfaces, qualitatively the microflora was very similar, and no significant differences were found in the plaque lactate/acetate ratios or pH measurements following a sucrose mouthrinse. Thus, human tooth specimens mounted on the intra-oral device produced a plaque ecosystem similar to that present on the adjacent natural dentition, suggesting that the model is suitable for studies on early plaque development and the microbiology of enamel demineralization.

Long-Term Exposure of Plaque to Zinc Citrate

The effect of 3 years’ continuous exposure to dentifrices containing different levels of sodium monofluorophosphate, with or without 0.5% zinc citrate, has been investigated on plaque growth inhibitio

An in-dwelling electrode for in-vivo measurement of the pH of dental plaque in man

A system for the measurement of plaque pH in vivo has been developed, using an in-dwelling miniature glass electrode. The reliability of the electrode and the closeness of the experimental conditions to natural ones compared favourably with previous techniques for measuring plaque pH. The effect on plaque pH of sucrose and saccharin rinses, and a chlorhexidine mouthwash were studied. Continuous small, rapid fluctuations in the pH of both stimulated and resting plaques were consistently observed and larger changes of pH were noted on opening the mouth and swallowing.

Fluoride Tablets and Salivary Fluoride Levels

Mixed salivary fluoride levels have been measured after 9 subjects sucked or slowly dissolved three different brands of 1 mg F–– fluoride tablets. Results indicate that for all preparations

The effect on human salivary fluoride concentration of consuming fluoridated salt-containing baked food items

Salt fluoridation is recognised world-wide as a proven and viable alternative means of consumer choice-related, community-based fluoridation where water fluoridation is either technically or politically impossible. However, as most salt consumed is contained within cooked food products, rather than sprinkled over prepared food at the table, the purpose of this study was to investigate the effects on salivary fluoride concentration of consuming baked food products prepared with 250 and 350 ppm fluoridated salt (as KF). Six food items were baked with (a) normal non-fluoridated salt, (b) 250 mg F/kg salt and (c) 350 mg F/kg salt. Eleven adult volunteers consumed these foodstuffs on separate occasions and salivary samples were collected for fluoride analyses before and at various time points (1-30 min) after eating. For most foodstuffs, small but significant increases in salivary fluoride concentration occurred for at least 5 min after ingestion of the fluoridated salt-containing items. Salivary fluoride concentrations peaked 1 or 2 min after eating, with highest values for the six test foods ranging from 0.16 to 0.25 ppm F, and from 0.18 to 0.44 ppm F for the 250 and 350 mg F/kg salt products, respectively. In all cases, salivary fluoride concentrations had returned to baseline by 20 min. The clinical significance of such small, short-term increases in salivary fluoride is uncertain, but the findings suggest that a more frequent intake of foods with fluoridated salt substituted for normal salt could help sustain slightly elevated salivary fluoride concentrations for more prolonged periods of the day, and might thus potentiate the cariostatic effects of saliva on tooth mineral.