N. Omid

Fluoridated toothpaste: usage and ingestion of fluoride by 4‐ to 6‐yr‐old children in England

Fluoridated toothpaste is effective for dental caries control, yet may be a risk factor for dental fluorosis. This study aimed to quantify fluoride ingestion from toothpaste by children and to investigate the effects of age, gender, and social class on the amount of fluoride ingested per toothbrushing session. Sixty-one children, 4-6 yr of age, were recruited: 38 were from low socio-economic (LSE) areas of Newcastle, UK, and 23 were from high socio-economic (HSE) areas of Newcastle, UK. All expectorated saliva, rinse water (if used), and residual toothpaste were collected after brushing at home and were analysed for fluoride. Of the children, 74% and 69% from HSE and LSE areas, respectively, claimed that they brushed twice per day. The mean (SD) weight of toothpaste dispensed was 0.67 (0.36) g. The mean (SD) amount of fluoride ingested per toothbrushing session and per day was 17.0 (14.7) and 29.3 (32.8) μg kg(-1) of body weight, respectively. Daily fluoride intake per kilogram of body weight did not differ significantly between children from LSE and HSE areas. Fluoride intake per toothbrushing session was significantly influenced by weight of toothpaste, its fluoride concentration, and the childs age. Whilst the average amount of toothpaste used per toothbrushing session was more than twice the recommended amount (of 0.25 g), only one child had a daily fluoride intake that exceeded the tolerable upper intake level of 0.1 mg kg(-1) of body weight for this age group.

Effect of Rinsing with Mouthwashes after Brushing with a Fluoridated Toothpaste on Salivary Fluoride Concentration

The aim of the study was to determine whether rinsing with a mouthwash after brushing with a fluoridated toothpaste affected oral fluoride (F) retention and clearance compared with an oral hygiene regime without mouthwash. In this supervised, single-blind study, 3 regimes were compared: (A) brushing for 1 min with 1 g of 1,450 μg F/g NaF toothpaste followed by rinsing for 5 s with 10 ml water; (B) as A but followed by rinsing for 30 s with 20 ml of 100 mg F/l NaF mouthwash, and (C) as B but rinsing for 30 s with a non-fluoridated mouthwash. Twenty-three adults applied each treatment once in a randomised order, separated by 1-week washout periods, and used a non-fluoridated toothpaste at home prior to and during the study. Whole saliva samples (2 ml), collected before each treatment commenced and 10, 20, 30, 60, 90 and 120 min afterwards, were subsequently analysed for fluoride by ion-specific electrode. The mean (SD) back-transformed log (area under salivary F clearance curve) values were: A = 2.36 (+3.37, –1.39), B = 2.54 (+2.72, –1.31) and C = 1.19 (+1.10, –0.57) mmol F/l × min, respectively. The values for regimes A and B were statistically significantly greater than that for regime C (p < 0.001; paired t test). These findings suggest that use of a non-F mouthwash after toothbrushing with a F toothpaste may reduce the anticaries protection provided by toothbrushing with a F toothpaste alone. The use of a mouthwash with at least 100 mg F/l should minimise this risk.

Fractional urinary fluoride excretion of 6-7-year-old children attending schools in low-fluoride and naturally fluoridated areas in the UK

F is an important trace element for bones and teeth. The protective effect of F against dental caries is well established. Urine is the prime vehicle for the excretion of F from the body; however, the relationship between F intake and excretion is complex: the derived fractional urinary F excretion (FUFE) aids understanding of this in different age groups. The present study aimed to investigate the relationships between (1) total daily F intake (TDFI) and daily urinary F excretion (DUFE), and (2) TDFI and FUFE in 6-7-year-olds, recruited in low-F and naturally fluoridated (natural-F) areas in north-east England. TDFI from diet and toothbrushing and DUFE were assessed through F analysis of duplicate dietary plate, toothbrushing expectorate and urine samples using a F-ion-selective electrode. FUFE was calculated as the ratio between DUFE and TDFI. Pearsons correlation and regression analysis were used to investigate the relationship between TDFI and FUFE. A group of thirty-three children completed the study; twenty-one receiving low-F water (0·30 mg F/l) and twelve receiving natural-F water (1·06 mg F/l) at school. The mean TDFI was 0·076 (SD 0·038) and 0·038 (SD 0·027) mg/kg per d for the natural-F and low-F groups, respectively. The mean DUFE was 0·017 (SD 0·007) and 0·012 (SD 0·006) mg/kg per d for the natural-F and low-F groups, respectively. FUFE was lower in the natural-F group (30 %) compared with the low-F group (40 %). Pearsons correlation coefficient for (1) TDFI and DUFE was +0·22 (P= 0·22) and for (2) TDFI and FUFE was − 0·63 (P< 0·001). In conclusion, there was no correlation between TDFI and DUFE. However, there was a statistically significant negative correlation between FUFE and TDFI.

Fluoride content of ready-to-feed (RTF) infant food and drinks in the UK.

BACKGROUND The level of Fluoride exposure needed to cause dental fluorosis is not known precisely. An awareness of total F intake from all sources, especially during the critical stages of dental development during infancy and early childhood, is important in preventing the development of dental fluorosis. OBJECTIVES The aim of the study was to measure F content of ready-to-feed (RTF) infant drinks and foods in the UK. METHODS In total, 122 infant foods were analysed for F concentrations, in triplicate, indirectly by an acid diffusion method and 25 infant drinks analysed directly using an F-ion-selective electrode after addition of TISABIII. RESULTS The median (range) F concentration was 0.110 (0.030-0.221) μg/g for breakfast cereals, 0.112 (0.040-1.200) μg/g for savoury meals, 0.056 (0.030-0.379) μg/g for desserts, 0.044 (0.020-0.191) μg/g for fruits, 0.196 (0.040-0.397) μg/g for baked goods, 0.069 (0.050-0.148) μg/ml for juices, 0.016 (0.009-0.030) μg/ml for milks and 0.041 (0.022-0.069) μg/ml for waters. The median (range) F concentration of all RTF infant foods and drinks by recommended age of consumption was 0.029 (0.010-0.245), 0.088 (0.020-0.500), 0.108 (0.100-0.510) and 0.108 (0.060-1.200) μg/g for infants from birth, 4+ month, 6+ month and 10+ month, respectively. CONCLUSION The results suggest that the F concentrations of UK-marketed RTF infant foods, drinks and formula milk are not sufficiently high to be a risk factor for dental fluorosis, if consumption is within the limits recommended for infants and young children.

Fluoride concentrations of Ready-to-Feed (RTF) infant foods and drinks in the UK

BACKGROUND The level of Fluoride exposure needed to cause dental fluorosis is not known precisely. An awareness of total F intake from all sources, especially during the critical stages of dental development during infancy and early childhood, is important in preventing the development of dental fluorosis. OBJECTIVES The aim of the study was to measure F content of ready-to-feed (RTF) infant drinks and foods in the UK. METHODS In total, 122 infant foods were analysed for F concentrations, in triplicate, indirectly by an acid diffusion method and 25 infant drinks analysed directly using an F-ion-selective electrode after addition of TISABIII. RESULTS The median (range) F concentration was 0.110 (0.030-0.221) μg/g for breakfast cereals, 0.112 (0.040-1.200) μg/g for savoury meals, 0.056 (0.030-0.379) μg/g for desserts, 0.044 (0.020-0.191) μg/g for fruits, 0.196 (0.040-0.397) μg/g for baked goods, 0.069 (0.050-0.148) μg/ml for juices, 0.016 (0.009-0.030) μg/ml for milks and 0.041 (0.022-0.069) μg/ml for waters. The median (range) F concentration of all RTF infant foods and drinks by recommended age of consumption was 0.029 (0.010-0.245), 0.088 (0.020-0.500), 0.108 (0.100-0.510) and 0.108 (0.060-1.200) μg/g for infants from birth, 4+ month, 6+ month and 10+ month, respectively. CONCLUSION The results suggest that the F concentrations of UK-marketed RTF infant foods, drinks and formula milk are not sufficiently high to be a risk factor for dental fluorosis, if consumption is within the limits recommended for infants and young children.

Estimation of daily dietary fluoride intake: 3-d food diary v . 2-d duplicate plate

The 3-d food diary method (3-d FD) or the 2-d duplicate plate (2-d DP) method have been used to measure dietary fluoride (F) intake by many studies. This study aimed to compare daily dietary F intake (DDFI) estimated by the 3-d FD and 2-d DP methods at group and individual levels. Dietary data for sixty-one healthy children aged 4-6 years were collected using 3-d FD and 2-d DP methods with a 1-week gap between each collection. Food diary data were analysed for F using the Weighed Intake Analysis Software Package, whereas duplicate diets were analysed by an acid diffusion method using an F ion-selective electrode. Paired t test and linear regression were used to compare dietary data at the group and individual levels, respectively. At the group level, mean DDFI was 0·025 (sd 0·016) and 0·028 (sd 0·013) mg/kg body weight (bw) per d estimated by 3-d FD and 2-d DP, respectively. No statistically significant difference (P=0·10) was observed in estimated DDFI by each method at the group level. At an individual level, the agreement in estimating F intake (mg/kg bw per d) using the 3-d FD method compared with the 2-d DP method was within ±0·011 (95 % CI 0·009, 0·013) mg/kg bw per d. At the group level, DDFI data obtained by either the 2-d DP method or the 3-d FD method can be replaced. At an individual level, the typical error and the narrow margin between optimal and excessive F intake suggested that the DDFI data obtained by one method cannot replace the dietary data estimated from the other method.

The fluoride contents of commercially-available soya milks in the UK

Background In some parts of the world, soya milks are found to be a significant source of fluoride (F). Among western commercial markets, although there has been a sustained increase in soya milk products available for purchase, there are limited data on their F content.Objective To determine the F content of soya milk products available in the UK market including fresh and ultra-high temperature products in addition to sweetened and unsweetened soya milks.Materials and methods Fifty-two traditional and UK-produced soya milk samples commercially available in northeast England were analysed to determine their F concentration using a modified hexamethyldisiloxane-facilitated diffusion method with a F-ion-selective electrode coupled to a potentiometer.Results The median F concentration of all products was 0.293 μg/ml ranging from 0.015 μg/ml to 0.964 μg/ml. The median F concentration of ultra-high temperature (UHT) (n = 42) milks was 0.272 μg/ml lower than 0.321 μg/ml obtained for fresh (n = 10) soya milks. Organic soya milks contained less F compared with non-organic for sweetened and unsweetened categories.Conclusion Commercially available soya milks in the UK do not pose an increased risk for dental fluorosis development. Further research is necessary into the manufacturing process of soya milks, which may influence the overall F content of the end product.

Comparison of total ionic strength adjustment buffers III and IV in the measurement of fluoride concentration of teas

Background: Tea is the second most consumed drink in the UK and a primary source of hydration; it is an important source of dietary fluoride (F) for consumers and also abundant in aluminium (Al). Varying ranges of F concentrations in teas have been reported worldwide which may be, in part, due to differences in analytical techniques used to measure this ion. Aim: The effect of using total ionic adjustment buffers (TISAB) III or IV when measuring F concentration of black teas available in the UK was investigated and compared. Based on this evaluation, the effects of three different infusion times, 1 min, 10 min and 1 h, caffeine content and tea form on the F contents of the tea samples were investigated. Methods: The F concentrations of 47 tea samples were measured directly using a fluoride ion-selective electrode (F-ISE), TISAB III and IV and infusion times of 1 min, 10 min and 1 h. Results: Mean (SD) F concentration of tea samples for all infusion times was statistically significantly higher (p < 0.001) measured by TISAB IV (4.37 (2.16) mg/l) compared with TISAB III (3.54 (1.65) mg/l). A statistically significant positive correlation (p < 0.001) was found between Al concentration (mg/l) and differences in F concentration (mg/l) measured using the two TISABs; the difference in F concentration measured by the two TISABs increased with the magnitude of Al concentration. Conclusion: Due to higher concentrations of F and Al in teas and their complexing potential, use of TISAB IV facilitates more accurate measurement of F concentration when using an F-ISE and a direct method.

Erosive characteristics and fluoride content of cola-type drinks

Aim Excessive consumption of carbonated soft drinks is detrimental to general and oral health. This study determined endogenous pH, titratable acidity (TA) and fluoride (F) ion concentration of cola-type drinks available in the UK. Subsidiary aims were to compare: (i) endogenous pH and TA of drinks upon opening (T0) and after 20 minutes (T20); (ii) endogenous pH, TA and F ion concentration of diet vs regular and plastic bottle vs canned drinks.Methods Endogenous pH, TA (mls 0.1M NaOH) and F ion (mg/L) of 71 products were measured using a pH meter and F-ISE. A Wilcoxon Signed Ranks Test compared pH and TAs at T0 and T20; a Mann-Whitney U test compared pH, TAs and F ion concentration for; a) regular vs diet drinks; and b) plastic bottle vs canned drinks.Results Mean (±SD) pH for regular and diet drinks was 2.44± 0.12 and 2.83± 0.33 respectively (p = 0.001). Mean NaOH (ml) to raise pH to 5.5 and 5.7 was 5.49± 0.76 and 6.40± 0.78 (regular drinks); 5.17±1.03 and 6.03±1.07 (diet drinks). Diet (p = 0.040) and regular (p = 0.041) drinks had higher TA to pH 5.7 at T0 compared with T20; at T20 regular drinks had higher TA to pH 5.5 (p = 0.026) and pH 5.7 (p = 0.030) than diet drinks. There was no difference in F ion concentration between regular vs diet drinks (p = 0.754) and no significant container effect.Conclusion Erosive characteristics were similar between manufacturers, but higher erosive potentials were evident at T0 compared with 20 minutes later and for regular compared with diet drinks. F ion concentration of drinks was low.

Urinary Fluoride Excretion in 6- to 7-Year-Olds Ingesting Milk Containing 0.5 or 0.9 mg Fluoride

Effectiveness of 0.5 mg fluoride (F) milk ingestion in preventing caries has been termed only ‘moderate’. In this 3-arm partial cross-over intervention, 32 children aged 6–7 years in a non-F area were recruited and urinary F excretion (UFE) measured before and after ingestion of 0.5 or 0.9 mg F milk. Maintaining customary dietary and oral hygiene habits, children underwent a 2-week ‘wash-in’ with non-F milk, providing a 24-hour urine sample on day 4 of non-F (baseline) and F milk ingestion containing either (i) 0.5 mg or (ii) 0.9 mg F (intervention). A comparative group of thirteen 6- to 7-year-olds living in fluoridated areas provided a 24-hour urine sample on day 4 of daily non-F milk ingestion, following a 2-week non-F milk wash-in. Valid urine samples were analysed for F and UFE estimated from corrected 24-hour urine volume and F concentration. For the 24 test children providing 2 valid urine samples, mean (95% CI) change in corrected 24-hour UFE was 0.130 (0.049, 0.211) and 0.153 (0.062, 0.245) mg/day for 0.5 mg (p < 0.007) and 0.9 mg F (p < 0.001) groups, respectively. Post-intervention, mean (SD) corrected 24-hour UFE was 0.437 (0.153) mg/day and 0.420 (0.188) mg/day for the 0.5 and 0.9 mg F groups, respectively, which were lower than the WHO provisional standards (0.48–0.60 mg F/day). F milk consumption significantly increased UFE; however, the F content of 0.5 and 0.9 mg F milk may be too low to achieve WHO provisional UFE standards concomitant with optimal F exposure in children aged ≥6 years.