A spectroscopic and surface microhardness study on enamel exposed to beverages supplemented with lower iron concentrations.

OBJECTIVES: This study aimed to compare the in vitro mineral loss and surface microhardness (SMH) changes in human enamel specimens following supplementation of acidic carbonated beverages with low iron concentrations than when treated without. STUDY DESIGN: 180 enamel blocks each from primary and permanent teeth were prepared and equally subdivided (n=10) for their respective treatments in Group 1 (Coca Cola and Sprite without iron supplementation) and Group 2 (beverages supplemented with 2/5 mmol/L FeSO4.7H2O). Following initial SMH estimation, the blocks were subjected to 3 treatment cycles of 5/20 minute incubation periods, equally interspaced by a 5-min treatment in artificial saliva. The calcium and phosphate released after each cycle were analyzed spectrophotometrically and the final SMH was recorded. The results were tested using student's T test, One-way ANOVA and Kruskal Walli's test (p<0.05). RESULTS: Two and five mmol/L FeSO4.7H2O supplementation produced a highly significant SMH change and calcium and phosphate reduction than when treated without (p<.0005). Both the enamel specimens showed similar patterns of mineral loss and SMH reduction, with pronounced effects in the twenty minute incubation cycles. CONCLUSION: Our results suggest that 2 mmol/L FeSO4.7H2O supplementation to acidic beverages is beneficial in reducing mineral loss and preserving surface microhardness of human enamel.

In situ evaluation of a low fluoride concentration gel with sodium trimetaphosphate in enamel remineralization.

PURPOSE: To evaluate the capability of gels with low fluoride (F) concentration and supplemented with sodium trimetaphosphate (TMP) to promote in situ enamel remineralization. METHODS: Bovine enamel blocks were selected on the basis of their surface hardness after demineralization, and divided into five groups: gel without F or TMP (placebo); gel with 4,500 ppm F (4,500); gel with 4,500 ppm F + 5% TMP (4,500 5% TMP); gel with 9,000 ppm F (9,000) and gel with 12,300 ppm F (12,300). The study design was blind and cross-over: 12 subjects used palatal devices with four demineralized enamel blocks for 3 days, after topical fluoride application (TFA). Two blocks were removed immediately for analysis of the loosely bound fluoride (CaF2) and firmly bound fluoride (F) after TFA in enamel. In the remaining blocks, the percentage of surface hardness recovery (% SH), cross-sectional hardness (deltaKHN) and CaF2 and F were determined after remineralization. The results were subjected to ANOVA and Bonferroni tests (P < 0.05). RESULTS: The groups 4,500 5% TMP, 9,000, and 12,300 showed the best results with regard to % SH (P < 0.05). Lower deltaKHN values were observed in the 4,500 5% TMP and 12,300 gel groups (P < 0.05). Higher concentrations of CaF2 and F were observed in the 12,300 group, followed by the 4,500 5% TMP and 9,000 groups (P > 0.05). It was concluded that it is possible to promote enamel remineralization using gels with low fluoride concentration supplemented with TMP.

Effect of resin composites with sodium trimetaphosphate with or without fluoride on hardness, ion release and enamel demineralization.

PURPOSE: To evaluate the effect of the addition of sodium trimetaphosphate (TMP) with or without fluoride on enamel demineralization, and the hardness and release of fluoride and TMP of resin composites. METHODS: Bovine enamel slabs (4 x 3 x 3 mm) were prepared and selected based on initial surface hardness (n = 96). Eight experimental resin composites were formulated, according to the combination of TMP and sodium fluoride (NaF): TMP/NaF-free (control), 1.6% sodium fluoride (NaF), and 1.5%, 14.1% and 36.8% TMP with and without 1.6% NaF. Resin composite specimens (n = 24) were attached to the enamel slabs with wax and the sets were subjected to pH cycling. Next, surface and cross-sectional hardness and fluoride content of enamel as well as fluoride and TMP release and hardness of the materials were evaluated. Data were statistically analyzed using ANOVA (P < 0.05). RESULTS: The presence of fluoride in enamel was similar in fluoridated resin composites (P > 0.05), but higher than in the other materials (P < 0.05). The combination of 14.1% TMP and fluoride resulted in less demineralization, especially on lesion surface (P < 0.05). The presence of TMP increased fluoride release from the materials and reduced their hardness.

In vitro evaluation of the effects of a fluoride-releasing composite on enamel demineralization around brackets.

OBJECTIVES: The aim of this in vitro study was to evaluate the effectiveness of a fluoride-releasing bonding agent in inhibiting enamel demineralization around orthodontic brackets after the exposure to a demineralizing solution. MATERIALS AND METHODS: Twenty-six extracted upper molars were bonded with two different composites: Transbond XT (TXT) and Transbond Plus (TPlus), fluoride-releasing (both 3M Unitek, Monrovia, CA, USA). The samples were exposed to an acid lactic solution for three days and then subjected to Metallographic Optical Microscope (MOM) and Scanning Electron Microscope/Energy Dispersive X-Ray (SEM/EDX) analyses. Enamel surface was examined in different areas: un-treated, etched and primer-painted, un-treated area with no acid exposure, central area with bracket bonded. The maximum demineralization depths and the fluoride content at 100, 200 and 300 µm depth were evaluated. RESULTS: MOM analysis showed statistically significant (p<0.001) differences in demineralization depth for TPlus group compared to TXT group with lower values for the first one. EDX analysis confirmed the presence of fluoride in TPlus group. CONCLUSIONS: The fluoride content of TPlus appeared able to weakly reduce the enamel demineralization.

Caries protective agents in human milk and bovine milk: an in vitro study.

OBJECTIVES: To estimate Calcium and Phosphorus withdrawal from hydroxyapatite in the presence of bovine milk and human milk from which the following protective fractions namely Casein, Whey protein, Lactose and Milk fat have been individually removed and to compare the above protective fractions in human and bovine milk. METHOD: Human milk obtained from lactating mothers in the labor ward of Kshema hospital was subjected to immediate analysis. Bovine milk was obtained from a local dairy. Equal quantities of human milk and bovine milk (1 ml) were separately subjected to the systematic removal of the four milk fractions. As each fraction was removed, the remaining milk samples were subjected to testing. Powdered hydroxyapatite from human dental enamel was subjected to demineralization with the addition of the milk sample under test for 20 minutes. This mixture was then centrifuged. Aliquots of the supernatant were taken for calcium and Phosphorus analysis using photospectrometry. Ten demineralization tests were similarly carried out for every milk fraction for both human and bovine milk separately. Equal samples of whole bovine milk and whole human milk were also subjected to similar testing. RESULTS: The calcium and phosphorus dissolution values were higher when the individual fractions were eliminated from both human milk/enamel samples and bovine milk/enamel samples as compared to the values obtained from whole human milk/whole bovine milk/enamel samples. Further higher calcium and phosphorus dissolution values were observed when the fractions were individually and separately removed from the whole human milk/enamel samples as compared to the corresponding values obtained when these fractions were removed from bovine milk/enamel samples. CONCLUSION: The evaluated milk fraction in bovine milk namely casein, whey protein, lactose and milk fat were individually more caries protective when compared to the corresponding fractions in human milk.

Alimentary fluoride intake in preschool children.

BACKGROUND: The knowledge of background alimentary fluoride intake in preschool children is of utmost importance for introducing optimal and safe caries preventive measures for both individuals and communities. The aim of this study was to assess the daily fluoride intake analyzing duplicate samples of food and beverages. An attempt was made to calculate the daily intake of fluoride from food and swallowed toothpaste. METHODS: Daily alimentary fluoride intake was measured in a group of 36 children with an average age of 4.75 years and an average weight of 20.69 kg at baseline, by means of a double plate method. This was repeated after six months. Parents recorded their child's diet over 24 hours and collected duplicated portions of food and beverages received by children during this period. Pooled samples of food and beverages were weighed and solid food samples were homogenized. Fluoride was quantitatively extracted from solid food samples by a microdiffusion method using hexadecyldisiloxane and perchloric acid. The content of fluoride extracted from solid food samples, as well as fluoride in beverages, was measured potentiometrically by means of a fluoride ion selective electrode. RESULTS: Average daily fluoride intake at baseline was 0.389 (SD 0.054) mg per day. Six months later it was 0.378 (SD 0.084) mg per day which represents 0.020 (SD 0.010) and 0.018 (SD 0.008) mg of fluoride respectively calculated per kg bw/day.When adding the values of unwanted fluoride intake from the toothpaste shown in the literature (0.17-1.21 mg per day) the estimate of the total daily intake of fluoride amounted to 0.554-1.594 mg/day and recalculated to the child's body weight to 0.027-0.077 mg/kg bw/day. CONCLUSIONS: In the children studied, observed daily fluoride intake reached the threshold for safe fluoride intake. When adding the potential fluoride intake from swallowed toothpaste, alimentary intake reached the optimum range for daily fluoride intake. These results showed that in preschool children, when trying to maximize the benefit of fluoride in caries prevention and to minimize its risk, caution should be exercised when giving advice on the fluoride containing components of child's diet or prescribing fluoride supplements.

A comparative study of pH modulation and trace elements of various fruit juices on enamel erosion: an in vitro study.

Fruit juices are popular worldwide with children of all ages as they are sweet and perceived to be healthful. This in vitro study was sought to measure pH of 10 different fruit juices, to find out possible erosive effects on human dental enamel of 40 extracted sound premolars and also to measure fluoride and trace elements of these juices. The estimation of pH of fruit juices was done by using Systronic upH 362 pH meter. The erosive effects of fruit juices were tested by using polarized light microscope. Orion electrode was used to measure fluoride. The trace elements were estimated by using Atomic Absorption Spectrophotometer No. 6501F. The pH values in different juices were observed at different levels, and pH values of these juices were more acidic than baseline after 24 hours. As the time increased, the erosion effect became more in pineapple; grape and sugarcane juices, and they had more cariogenic trace elements like selenium, iron and manganese. So, these juices were found to be cariogenic. To conclude, orange, mousambi, mango, pomegranate, apple, chikku and watermelon juices had no erosive effect on the human enamel, with the presence of highest amount of trace elements like fluoride and phosphorous which are considered as strongly cariostatic.

Effects of zinc and fluoride on the remineralisation of artificial carious lesions under simulated plaque fluid conditions.

The aim was to study the effects of zinc (Zn) and fluoride (F) on remineralisation at plaque fluid concentrations. Artificial carious lesions were created in 2 acid-gel demineralising systems (initially infinitely undersaturated and partially saturated with respect to enamel) giving lesions with different mineral distribution characteristics (high and low R values, respectively) but similar integrated mineral loss values. Lesions of both types were assigned to 1 of 4 groups and remineralised for 5 days at 37°C. Zn and F were added, based on plaque fluid concentrations 1 h after application, to give 4 treatments: 231 µmol/l Zn, 10.5 µmol/l F, Zn/F combined and an unmodified control solution (non-F/non-Zn). Subsequently remineralisation was measured using microradiography. High-R lesions were analysed for calcium, phosphorus, F and Zn using electron probe micro-analysis. All lesions underwent statistically significant remineralisation. For low-R lesions, remineralisation was in the order F(a) < non-F/non-Zn(a) < Zn(a, b) < Zn/F(b), and for high-R lesions F(a) < non-F/non-Zn(b) < Zn(b) < Zn/F(c) (treatments with the same superscript letter not significantly different, at p < 0.05). Qualitatively, remineralisation occurred throughout non-F/non-Zn and Zn groups, predominantly at the surface zone (F) and within the lesion body (Zn/F). Electron probe micro-analysis revealed Zn in relatively large amounts in the outer regions (Zn, Zn/F). F was abundant not only at the surface (F), but also in the lesion body (Zn/F). Calcium:phosphate ratios were similar to hydroxyapatite (all). To conclude, under static remineralising conditions simulating plaque fluid, Zn/F treatment gave significantly greater remineralisation than did F treatment, possibly because Zn in the Zn/F group maintained greater surface zone porosity compared with F, facilitating greater lesion body remineralisation.

Total and free fluoride concentrations of African dentifrices marketed in West Africa.

OBJECTIVE: To determine the fluoride concentrations of commercial dentifrices marketed in West Africa. DESIGN: In vitro measurement of the total fluoride concentration by liquid gas chromatography, and of the free fluoride concentration with a fluoride sensitive electrode. SETTING: Collection of fluoride dentifrices in public markets and supermarkets in and around the capital of The Republic of The Gambia, Banjul, after a systematic search. MATERIALS: All commercially available different brands sold in The Gambia and produced locally or in other African countries (Egypt, Morocco, Nigeria and South Africa). OUTCOME MEASURES: Total and free fluoride concentrations of dentifrices in parts per million. RESULTS: Seven different dentifrices were detected with NaMFP as the predominant fluoride source. Four dentifrices showed a total fluoride concentration above 1,000 ppm F-. The products showed - in general - a lower free fluoride concentration. Only one product with NaF as fluoride supplement showed both total and free fluoride concentrations above 1,000 ppm F-. Four products contained calcium-based abrasive additives. CONCLUSION: The measurement of total and free fluoride concentrations of dentifrices available in The Gambia (West Africa) showed inhomogeneities. This was particularly verified where fluoride compounds were combined with calcium-based abrasives. If so, it is recommended that the total fluoride content should be measured by gas chromatography. Periodic quality control of dentifrices should be introduced in areas with an under-developed consumer-counselling infrastructure.

Diode laser irradiation and fluoride uptake in human teeth.

AIM: To evaluate chemically the effects of diode laser on fluoride uptake before and after laser irradiation of enamel surfaces. METHODS: Crowns of 20 sound human teeth were halved and a 3 x 3 mm acid-resistant varnish uncovered window left for: A) no treatment; B) fluoride (Elmex gel); C) diode (fluoride + diode laser); D) diode (diode laser + fluoride). The dental surfaces were analysed using a fluoride ion-selective electrode, in order to evaluate the fluoride treatment in combination with a diode laser. Also, to investigate laser-induced compositional changes (contents in F(-)) in enamel before/after laser irradiation and topical fluoride application. RESULTS: The mean ± SD of fluoride uptake of teeth of group A was 1.55 ± 0.89 mg/l. Mean fluoride uptake increased sevenfold after fluoride gel treatment: 10.51 ± 3.38 mg/l for group B, up to 15 times after gel and laser treatment: 23.62 ± 3.58 mg/l for group C and was 22.7 ± 4.60 mg/l for group D (diode laser before fluoride application). The Kruskal Wallis test indicated a statistically significant effect of fluoride uptake for all three treatments (p<0.001). The Student-Newman-Keuls multiple comparison test indicated a statistically significant increase of fluoride uptake before and after all treatments, and also a statistically significant difference for laser treatment versus fluoride gel. However, there was no statistically significance difference between laser groups. CONCLUSIONS: There is an enhanced capability of lasers to increase fluoride uptake of enamel and providing protection to enamel surface from acid attack.

Exposure to lead exacerbates dental fluorosis.

AIM: Our aim was to test the hypothesis that co-exposure to lead and fluoride alter the severity of enamel fluorosis. MATERIALS AND METHODS: Wistar rats were allocated in four groups: control, and 3 groups that received water containing 100 ppm of fluoride (F), 30 ppm of lead (Pb), or 100 ppm of F and 30 ppm of Pb (F+Pb) from the beginning of gestation. Enamel analysis and F and Pb determinations in enamel, dentine, and bone were performed in 81-day-old animals. Fluorosis was quantified using a new fluorosis index based on the identification of incisor enamel defects (white bands and white islets, representing hypomineralization, and cavities) weighted according to their severity and quantity. Hypomineralization was validated histopathologically by polarizing microscopy and microradiography. Scores were given by two blinded calibrated examiners (intra and interexaminer kappa values were 0.8 and 0.86, respectively). RESULTS: The control and the Pb groups presented normal enamel. The F+Pb group presented more severe enamel defects compared with the F group (P<0.0001). CONCLUSIONS: This study shows that lead exacerbates dental fluorosis in rodents, suggesting that co-exposure to lead may affect the degree of fluorosis.

Fluoride content of commercially-available bottled water in Bangkok, Thailand.

AIM: To determine the fluoride content of commercially-available bottled water in Bangkok. METHODS: Thirty brands of bottled water (17 bottled plain water and 13 bottled mineral water) were obtained from supermarkets in Bangkok. Two randomly-selected samples of each brand were purchased 6 months apart. A 5-mL sample was mixed with 5 mL of total ionic-strength adjusting buffer III. The fluoride content of each sample was determined in triplicate by a fluoride ion-selective electrode. Fluoride standards ranging in concentration from 0.01 to 1.00 ppm were used to calibrate the measurements. Data were analyzed by Statistical Package for the Social Sciences software, version 13.0. RESULTS: The fluoride content of bottled water in Bangkok ranged from 0.03 to 0.72 ppm, with a mean ± standard deviation of 0.17 ± 0.16 ppm. The mean fluoride content of bottled mineral water was slightly higher than that of bottled plain water, but the difference was not statistically significant. CONCLUSIONS: Most commercially-available bottled water in Bangkok contains negligible amounts of fluoride. This serves as baseline data for dentists prescribing a fluoride supplement to make the utmost use of the fluoride caries preventive effect, while avoiding adverse effects, such as dental fluorosis.

Associations between fluorosis of permanent incisors and fluoride intake from infant formula, other dietary sources and dentifrice during early childhood.

OBJECTIVES: The authors describe associations between dental fluorosis and fluoride intakes, with an emphasis on intake from fluoride in infant formula. METHODS: The authors administered periodic questionnaires to parents to assess children's early fluoride intake sources from beverages, selected foods, dentifrice and supplements. They later assessed relationships between fluorosis of the permanent maxillary incisors and fluoride intake from beverages and other sources, both for individual time points and cumulatively using area-under-the-curve (AUC) estimates. The authors determined effects associated with fluoride in reconstituted powdered infant formulas, along with risks associated with intake of fluoride from dentifrice and other sources. RESULTS: Considering only fluoride intake from ages 3 to 9 months, the authors found that participants with fluorosis (97 percent of which was mild) had significantly greater cumulative fluoride intake (AUC) from reconstituted powdered infant formula and other beverages with added water than did those without fluorosis. Considering only intake from ages 16 to 36 months, participants with fluorosis had significantly higher fluoride intake from water by itself and dentifrice than did those without fluorosis. In a model combining both the 3- to 9-months and 16- to 36-months age groups, the significant variables were fluoride intake from reconstituted powder concentrate formula (by participants at ages 3-9 months), other beverages with added water (also by participants at ages 3-9 months) and dentifrice (by participants at ages 16-36 months). CONCLUSIONS: Greater fluoride intakes from reconstituted powdered formulas (when participants were aged 3-9 months) and other water-added beverages (when participants were aged 3-9 months) increased fluorosis risk, as did higher dentifrice intake by participants when aged 16 to 36 months. CLINICAL IMPLICATIONS: Results suggest that prevalence of mild dental fluorosis could be reduced by avoiding ingestion of large quantities of fluoride from reconstituted powdered concentrate infant formula and fluoridated dentifrice.

Combination of high-fluoride toothpaste and no post-brushing water rinsing on enamel demineralization using an in-situ caries model with orthodontic bands.

OBJECTIVE: To compare the effects on enamel demineralization and fluoride (F) retention of two different brushing­rinsing regimens. MATERIAL AND METHODS: An in-situ caries model with orthodontic bands was used for 8­9 weeks. A total of 20 orthodontic patients participated. They were randomized into two groups: (1) a test group using 5000 ppm F (n = 10) with no post-brushing water rinsing; and (2) a control group using 1450 ppm F (n = 10) with three sessions of post-brushing water rinsing. Orthodontic stainless-steel bands were applied to the two upper first premolars, leaving 2­3 mm of space away from the exposed buccal surface in order to accumulate plaque and provoke initial caries development. The teeth were extracted after 8 and 9 weeks, then analysed using quantitative light-induced fluorescence (QLF). Additionally, oral F retention was compared for the two groups. RESULTS: In comparison to the control group, the test regimen resulted in a non-significant smaller QLF lesion area and a significantly lower average QLF loss of fluorescence (P < 0.05). The highest F retention concentration under the band was found in the test group (P < 0.001). CONCLUSIONS: The combination of using a 5000 ppm F toothpaste and no post-brushing water rinsing had a greater anti-caries potential and resulted in elevated oral F retention compared to a 1450 ppm F toothpaste with three sessions of post-brushing water rinsing.

Fluoride content of beverages intended for infants and young children in Poland.

Results of the studies indicate that fluoride content in beverages may be highly variable and children can consume substantial amounts of fluoride with these products. Ingestion of excessive fluoride during infancy and early childhood may cause dental fluorosis of permanent maxillary central incisors--the most aesthetically important teeth. The aim of this study was to determine the fluoride content in Polish beverages designed for infants and young children nutrition. Forty-three brands of juices and juice-flavored drinks and 23 instant teas were evaluated. Analyses were performed with the use of ion-selective fluoride electrode (09-37 type) and a RAE 111 chloride-silver reference electrode (MARAT). Fluoride concentrations in most beverages did not exceed 0.3 ppm. However, in three beverages containing tea extract levels of fluoride were higher (0.35-1.14 ppm). Consumption of these beverages could significantly increase child's fluoride exposure. Therefore, the need exists for continuous monitoring of fluoride levels in products intended for children. Listing fluoride content on beverages would be desirable. Knowledge about possible fluoride ingestion from dietary sources permits the clinician to recommend the safest schedule of fluoride treatment so as the optimal caries preventive effect can be obtained and the risk of dental fluorosis reduced.

Differences in exposure and biological markers of fluoride among White and African American children.

OBJECTIVE: To determine differences in self-reported fluoride exposure and fluoride exposure biomarkers between two racial groups. METHODS: Questionnaires regarding fluoride exposure, urine and water collection kits were distributed to African American and White 7-14-year-old children. Children received a dental exam for fluorosis. Water, urine, and saliva were analyzed for fluoride content. Questionnaire responses and results of sample analyses were compared and observed differences were analyzed. RESULTS: 83 African American and 109 White children completed the study. Dental fluorosis was observed in 62.5 percent White and 80.1 percent African American children. Significant differences were found for fluorosis prevalence and severity between the groups (P < 0.05). Less African American children reported having used fluoride supplements in the past. White children began brushing their teeth at an earlier age. More White children visited a dentist for the first time before age 3. African American children reported currently using larger amounts of toothpaste. More Whites than African Americans had received topical fluoride treatments over the previous year. All of these differences were significant. Multivariate models showed that supplement use and amount of toothpaste used for brushing had significant associations to a child's fluorosis scores. Fluoride concentration of water and saliva was not different for the two groups; however, the fluoride content in urine was significantly higher in African Americans than in Whites [P < 0.05; 1.40 +/- standard deviation (SD) 0.65 ppm versus 1.08 +/- SD 0.28 ppm]. CONCLUSIONS: Differences in fluoride exposure between two racial groups were observed. These differences are complex and need to be better defined.

Effect on de novo plaque formation of rinsing with toothpaste slurries and water solutions with a high fluoride concentration (5,000 ppm).

The aim of this study was to evaluate the effect, on de novo plaque formation, of rinsing with toothpaste slurries and water solutions containing a high concentration of fluoride (F). Sixteen subjects rinsed three times per day for 4 d with dentifrice slurries containing 5,000, 1,500, and 500 ppm F, while 12 subjects rinsed with water solutions containing 5,000, 1,500, 500, and 0 ppm F, and 1.5% sodium lauryl sulphate (SLS). Plaque was scored [using the Quigley & Hein index (QHI)] after each 4-d period. Plaque samples for F analysis were collected. Significantly less plaque was scored for the dentifrice slurry containing 5,000 ppm F (buccal and all surfaces) and for 1.5% SLS (buccal surfaces). The differences in plaque scores between dentifrice containing 5,000 and 1,500 ppm F were 19% for all surfaces and 33% for buccal surfaces. The difference between the water solutions containing 1.5% SLS and 1,500 ppm F for buccal surfaces was 23%; the corresponding difference for 5,000 ppm F was 17%. The dentifrice slurry containing 5,000 ppm F accumulated 56% more F in plaque. The combination of high levels of F and SLS in dentifrice reduces de novo plaque formation and increases the accumulation of F in plaque after 4 d.

Effect of long-term consumption of milk supplemented with probiotic lactobacilli and fluoride on dental caries and general health in preschool children: a cluster-randomized study.

The aim of this study was to evaluate the effect of milk supplemented with probiotic bacteria and fluoride on caries development and general health in preschool children. Children 1-5 years of age (n = 248) attending 14 day care centres with 27 units in northern Sweden entered the study. The centres were randomly assigned to two parallel groups: children in the intervention group were served 150 ml milk supplemented with Lactobacillus rhamnosus LB21 (10(7) CFU/ml) and 2.5 mg fluoride per litre for lunch while the control group received standard milk. The double-blind intervention lasted for 21 months (weekdays) and data were collected through clinical examinations and questionnaires. The primary outcome was caries increment and secondary outcomes were measures of general health. The dropout rate was 25%. The mean baseline caries experience was 0.5 dmfs in the intervention units and 0.6 in the control units and after 21 months 0.9 and 2.2 (p < 0.05). The number of days with sick leave was similar in both groups but the children of the intervention units displayed 60% fewer days with antibiotic therapy (mean 1.9 vs. 4.7 days) and 50% less days with otitis media (0.5 vs. 1.0) (p > 0.05). In children who had participated during the whole 21-month intervention, fewer days with otitis media were reported (0.4 vs. 1.3 days, p < 0.05). No serious side effects were reported. It is concluded that daily consumption of milk containing probiotic bacteria and fluoride reduced caries in preschool children with a prevented fraction of 75%. Additional beneficial health effects were evident.

Kinetics of fluoride release from glass components of glass ionomers.

OBJECTIVES: To compare the F release from glass ionomer glasses (GICs) into water changed periodically with release into an unchanged "sink" [Williams JA, Billington RW, Pearson GJ. The glass ionomer cement: the sources of soluble fluoride. Biomaterials 2002;23:2191-200]. To evaluate the effect of replacing Ca wholly or partially by Sr. To compare two different methods of decomplexing F containing species. METHODS: All four glasses contained Al, Si, P, O and F. Glass AH2 (Advanced Healthcare Ltd.) had Na and Ca, LG26 (Advanced Healthcare Ltd.) had Ca, LG26Sr (ULTRASET project) had Ca and Sr, and LG125 (ULTRASET project) had Sr. Glasses were tested: after ball-milling, after washing in dilute acid, and W mixed with 35% acetic acid to form a "pseudo-cement". F(-) release was from 130mg samples into 10ml of deionised water changed at 1, 3, 7, 14, 21, 28, 35, and 42 days. Analysis was carried out: (a) using ISE without decomplexing, (b) using TISAB buffer, and (c) acid hydrolysis+TISAB (after Hattab). RESULT: The cumulative release rates from all glasses and treatments are linear with respect to t(1/2) with r=0.97 or greater (p=<0.001). F release into a "sink" showed no such correlation. The higher release rate from AH2 is more than accounted for by its higher F content. Most F release is not complexed except of AH2. AH2 has 20% of complex fluoride from raw glass, 44% from acid-washed glass and 51% from pseudo-cement. More fluoride is released after acid treatment from all 4 glasses, these are on average 4.4 times higher from acid-washed glass and 5.3 times higher from pseudo-cement. For TISAB fluoride release, LG26Sr is 26% more than LG26. Hattab fluoride>TISAB fluoride only for raw glasses. CONCLUSIONS: Changing water produces diffusion controlled kinetics. Acid treated will increase the complex fluoride from AH2. Replacing Ca by Sr enhances F release rate slightly.

[Dental fluorosis: an epidemiological investigation in the area of Ouardanine in Tunisia]. / La fluorose dentaire: enquête epidémiologique dans la région de ouardanine en Tunisie.

In this work, we carried out a transverse epidemiological investigation about the oral health state of pupils in the Ouardanine area. The investigation concerned 300 fifteen-year-old pupils. An amount of fluoride was administrated within drinking water. Further studies, within few years, will be desirableto follow the fluorosis evolution in this area.