Plaque Fluoride Concentrations Research Articles

A method for the quantitative site-specific study of the biochemistry within dental plaque biofilms formed in vivo.

The study of plaque biofilms in the oral cavity is difficult as plaque removal inevitably disrupts biofilm integrity precluding kinetic studies involving the penetration of components and metabolism of substrates in situ. A method is described here in which plaque is formed in vivo under normal (or experimental) conditions using a collection device which can be removed from the mouth after a specified time without physical disturbance to the plaque biofilm, permitting site-specific analysis or exposure of the undisturbed plaque to experimental conditions in vitro. Microbiological analysis revealed plaque flora which was similar to that reported from many natural sources. Analytical data can be related to plaque volume rather than weight. Using this device, plaque fluoride concentrations have been shown to vary with plaque depth and in vitro short-term exposure to radiolabelled components may be carried out, permitting important conclusions to be drawn regarding the site-specific composition and dynamics of dental plaque.

Fluoride Concentration, Mutans Streptococci and Lactobacilli in Plaque from Old Glass lonomer Fillings

Previous studies have found that the fluoride concentration of plaque growing on or adjacent to glass ionomer cement (GIC) is increased and the proportion of mutans streptococci in plaque is reduced. So far, there are only a few studies of the long-term effect of glass ionomer fillings on plaque in vivo. The aim of this study was to determine whether old GIC fillings have effects on plaque fluoride and microflora and whether this effect can be increased by topical application of fluoride on GIC fillings in vivo. The participants were 27 adults with at least 3 GIC fillings about 3 years old. Plaque was collected from sites adjacent to the GIC fillings and from the contralateral teeth, after which a 1.2% fluoride gel was applied to all teeth. Three days later, plaque was collected from the same sites as before. Stimulated saliva was also collected at both appointments. The results show that none of the patients had elevated levels of fluoride in their saliva either before or 3 days after the fluoride treatment. The fluoride concentration was 0.51 microgram/mg protein in plaque on GICs and 0.35 microgram/mg protein in plaque on contralateral teeth (p = 0.028). After the fluoride treatment, the respective fluoride concentrations were 0.59 microgram/mg and 0.75 microgram/mg (p = 0.849). No significant differences in the proportion of mutans streptococci and lactobacilli in plaque from GIC and contralateral teeth were found. The results suggest that the fluoride concentration of plaque growing on old GIC fillings is slightly increased. In this study, however, this had no significant effect on the cariogenic microflora.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer simulation of oral fluoride clearance

The presence of fluoride in saliva and dental plaque is important for prevention of dental caries. The elimination of fluoride from the oral cavity after introduction of a fluoride containing agent is a complicated physiological process. This process was simulated with a Pascal program running under MS-DOS on IBM-compatible microcomputers. The program calculated the fluoride concentration in saliva as a function of time from several input parameters, the most important being the amount of fluoride, salivary stimulation due to the fluoride vehicle, resting salivary flow rate and volume factors. Furthermore, factors such as excretion of fluoride in the saliva following fluoride absorption in the intestinal tract were modeled. The fluoride concentration in dental plaque due to diffusion was also calculated. Output was directed to files which could be processed by a graphics interface. The results of the computations were very similar to findings in vivo.

The effect of salivary clearance of sucrose and fluoride on human dental plaque acidogenicity

Ten subjects rinsed with a 20% (0.58 M) sucrose solution with or without 0.2% NaF (905 parts/10 6 F −) added in two separate experiments. Saliva and plaque were collected before rinsing and after 2, 5, 10 and 30 min. Sucrose and fluoride concentrations in saliva and acid anion and fluoride concentrations in plaque were analysed. There was a statistically significant and positive correlation between the concentration of sucrose in the saliva 2 min after the rinse and the subsequent concentrations of lactate in plaque at 10 and 30 min after the rinse with sucrose alone but not in the presence of fluoride. Salivary fluoride concentrations during 2–30 min after the sucrose rinse were significantly correlated with plaque fluoride concentrations during the same time. The addition of fluoride to the sucrose rinse significantly inhibited lactate production.

Fluoride in plaque following use of dentifrices containing sodium monofluorophosphate.

Previous work showed that plaque fluoride increased with increasing NaF content of mouthwashes following daily use. The main aim of this study was to test whether a similar relationship was detectable after regular use of dentifrices containing amounts of sodium monofluorophosphate equivalent to 1000, 1500, and 2500 micrograms F/g. Plaque was collected from three groups, each consisting of approximately 80 children, who had each used one of the dentrifrices for one year. Plaque fluoride increased significantly with increasing Na2FPO3 content of the dentifrices. For the 1000-micrograms-F/g group, plaque fluoride also increased significantly with increasing frequency of dentifrice use, but did not correlate with amount of dentifrice applied per brushing. The inverse correlation observed between mean plaque fluoride concentrations and mean three-year caries increments suggests that oral fluoride measurements may prove valuable in estimating the likely anti-caries efficacy of fluoride-containing dental products.

天然フッ素地区ならびに非フッ素地区の小児（４〜５歳および１４〜１５歳）のプラーク中フッ素濃度の測定

Total fluoride (F) concentrations in dental plaque obtained from children aged 4-5yr and 14-15yr in F area (0.3-1.8ppm F in natural drinking water) and non F area (under 0.1ppm F) were determined by the AlF molecular absorption spectrometry. The logarithmic normal distribution was showed in F concentration of dental plapue. The geometric means of F concentration in plaque obtained from the non F area were 25.7ppm (4-5yr) and 18.1ppm (14-15yr) as dry weight. The contents of plaque in F area, contrary, were significantly higher than those in non F area (4-5yr: 54.4ppm, 14-15yr: 24.3ppm).The plapue F from 4-5yr group was significantly higher than that from 14-15yr group in both areas. A possible explanation for the different levels of F in dental plaque from two age groups might be due to the difference of plaque quality such as plapue age.The present experiments confirmed the higher levels of F in dental plaque were acquired from naturaly fluoridated drinking water.

Evaluation of an intraoral controlled release delivery system for fluoride in primates.

An intraoral delivery system designed to release 0.5 mg of fluoride per day was evaluated in short-term studies in primates. This fluoride-releasing device, bonded to the buccal surface of the maxillary right central incisor of each of six monkeys (Macaca fascicularis), produced marked elevations in saliva and plaque fluoride concentrations without increases in serum fluoride concentrations. No changes were observed in the plaque and gingival scores or the populations of various species of plaque bacteria.

Fluoride concentration in dental plaque of naval recruits with and without caries

Plaque samples were evaluated for fluoride concentration, the degree of the fluoride binding and uptake of fluoride from 1 and 225 parts/10 6 F solutions. The plaque of the caries-free individuals contained significantly higher fluoride concentrations, but no difference was found in binding strength between the caries-free and caries-active groups. Uptake of fluoride from a 1 part/10 6 solution was slightly less for plaque of caries-free recruits, but there was no difference between the groups in uptake from the more concentrated solution.

Correlations between fluoride concentration, sample weight and acid production in dental plaque from children

Plaque was collected from 60 children aged 7 yr who were participating in a short-term study on the effect of fluoridized milk on plaque F. Plaque F was unaffected by 1 or 5 parts 10 6 F in milk. Correlations and partial correlations were calculated between: plaque weight, plaque F and the initial and final pH of plaque/sugar incubations. The mean (±SD) plaque weight was 10.1 mg (±4.83) and plaque F (wet weight) was 3.5 parts 10 6 (±1.79). Plaque F was significantly correlated with final pH ( r = +0.42; p < 0.01) but the correlation was of border-line significance ( r = +0.23; p = 0.06) when data were standardized on weight. Plaque F and weight were significantly correlated ( r = −0.33; p < 0.05). The correlation between weight and final pH ( r = −0.64; p < 0.01) was little affected by standardizing the data on initial pH or plaque F. The results indicate the importance of considering the weight of plaque when comparing F concentration or pH changes in plaque. The findings do not cast doubt on the validity of earlier results suggesting that pH falls were smaller in plaques from high fluoride areas because there is no evidence that fluoridated water reduced plaque weight.

A study of inorganic constituents in dental plaque.

The presence of human enamel did not affect the inorganic composition of plaque grown under standardized conditions on an intraoral device. Only enamel recently topically treated with fluoride increased plaque-fluoride concentrations beyond the average value of 25 ppm dry weight (about a tenth of previously reported values).