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.

Effect of a third application of toothpastes (1450 and 5000 ppm F), including a 'massage' method on fluoride retention and pH drop in plaque.

OBJECTIVE: The aim was to investigate fluoride (F) retention in plaque, saliva and pH drop in plaque using high-F toothpaste (5000 ppm F) or standard toothpaste (1450 ppm F) twice a day or 3-times a day. A method using the toothpaste as a 'lotion' and massaging the buccal surfaces with the fingertip was also evaluated. MATERIALS AND METHODS: The investigation had a randomized, single-blinded, cross-over design and 16 subjects participated in six brushing regimes: (1) 5000 ppm F; twice a day, (2) 5000 ppm; 3-times/day, (3) 5000 ppm; twice a day, plus the 'massage' method once a day, (4) 1450 ppm F; twice a day, (5) 1450 ppm; 3-times/day and (6) 1450 ppm; twice a day, plus the 'massage' method once a day. The outcome measure was F retention in plaque, saliva and the plaque-pH change after a sucrose rinse. RESULTS: The highest F concentration was found using high-F toothpaste (No 1-3) and differed significantly from those with 1450 ppm (No 4-6). Brushing with high-F toothpaste 3-times a day (No 2) resulted in a 3.6-times higher F saliva value compared with standard toothpaste twice a day (No 4) (p < 0.001). Increasing the frequency of application, from twice to 3-times a day, increased the F retention in plaque significantly when the two methods for application 3-times a day were pooled (p < 0.05). Brushing with 5000 and 1450 ppm toothpastes twice a day plus the 'massage' once a day resulted in the same F concentration in saliva and plaque as brushing 3-times a day with the same paste. CONCLUSION: A third application of toothpaste is increasing the F retention and toothpaste as a 'lotion' and massaging the buccal surfaces with the fingertip may be a simple and inexpensive way of delivering F a third time during the day.

Effect of iron II on hydroxyapatite dissolution and precipitation in vitro.

The aim of this study was to evaluate the effect of iron II on the dissolution and precipitation of synthetic hydroxyapatite (HA). HA powder was suspended in solutions of iron (0.84 µg/ml, Fe0.84; 18.0 µg/ml, Fe18; 70.0 µg/ml, Fe70), fluoride (1,100 µg/ml, F1,100), and deionized water and submitted to pH cycling. After pH cycling, the samples were analyzed by infrared spectroscopy and X-ray diffraction. The concentrations of fluoride, calcium, phosphorus, and iron were also analyzed. The data were submitted to ANOVA, and analyzed by Tukey's test (p < 0.05). The infrared spectrum showed a reduction in all bands corresponding to phosphates and hydroxyls and an increase in the carbonate band in the groups with iron. The intensity of the phosphate bands increased and that of the hydroxyl bands decreased in the group F1,100. It was observed that there was a higher concentration of Ca in the group F1,100, with no significant difference between the groups Fe18 and Fe70 (p > 0.05). There was an increase in Fe concentration in the HA directly related to the Fe concentration of the treatment solutions. Results show that the presence of Fe causes the precipitation of apatite with high solubility.

Evaluation of the efficacy of two mouthrinses formulated for the relief of xerostomia of diverse origin in adult subjects.

OBJECTIVE: To evaluate the efficacy of two new mouthrinses in the reduction of xerostomía-associated symptomatology. BACKGROUND: Xerostomia is a common chronic health condition that affects a great number of adults and significantly deteriorates quality of life, such that treatment is necessary. MATERIALS AND METHODS: Sixty-seven adult subjects of both sexes presenting xerostomia of diverse origin were selected. Mouthrinses were tested using a double-blind, randomized, cross-over clinical trial with an intervining wash out period. RESULTS: The 100% of subjects presented sensation of dry mouth, and 86% stated sensation of thick saliva. Burning tongue sensation, need to drink liquids to swallow and the sensation of swallowing difficulty were recorded in more than 50% of the patients. The most frequent pathologies in the sample were depression, arthritis, and arterial hypertension. Results of the clinical tests showed that mouthrinse 1 relieves sensation of dry mouth, need to drink liquids, and swallowing difficulty. In contrast, mouthrinse 2 relieves only latter two symptoms. Both rinses were more effective in relieving xerostomía-associated symptomatology in patients taking 3 or more medicines simultaneously. CONCLUSION: Both mouthrinses were effective in relieving various xerostomia symptoms, could be distributed at a low cost, thereby improving the quality of life of population affected.

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.

Effect of fluoride exposure on bone metabolism indicators ALP, BALP, and BGP.

OBJECTIVE: To analyze the changes in serum alkaline phosphatase (ALP) and bone alkaline phosphatase (BALP) activity and changes in osteocalcin (BGP) content following fluoride exposure and, thereby, determine the reference indications of fluoride-induced changes in bone metabolism. METHODS: In the animal study, rats were allowed free access to drinking water containing different concentrations (10, 150, or 400 mg/L) of sodium fluoride. Serum ALP and BALP activity and serum BGP content were assessed at three exposure time-points. In the spot study, serum ALP and BALP activity and serum BGP content were assessed in workers exposed to fluoride in their working environment for different periods of time. RESULTS: Compared with the control group, on days 15 and 30, the activity of serum ALP in the low- and medium-dose group was significantly higher (p < 0.05), while in the high-dose group it was significantly lower (p < 0.05). Only on day 30 was the activity of serum BALP in the medium-dose group significantly higher than that of the control group (p < 0.05). BGP content was lower in the high-dose group than in the control group (p < 0.05) on days 30 and 90, but it was higher in the medium-dose group on day 90. Compared with the control group, BGP content in the fluoride-exposed group was higher (p < 0.05). In the spot study, serum ALP activity and serum BGP content in the medium working-age group were higher than that in the short working-age group (p < 0.05). However, serum ALP activity and serum BGP content were lower in the long working-age group than in the medium working-age group (p < 0.05). CONCLUSIONS: Our results suggest that serum fluoride and urinary fluoride can be used as reference indications to provide an overall reflection of the body's fluoride-load and fluoride exposure level. Serum ALP activity and serum BGP content can be used as important reference indications for diagnosing bone metabolism changes resulting from fluoride exposure.

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.

Effect of boron as an antidote on dry matter intake, nutrient utilization and fluorine balance in buffalo (Bubalus bubalis) exposed to high fluoride ration.

It is well known that excessive accumulation of fluorides can exert toxic effects on various tissues and organs so as to severely damage the health and production of animals. The aim of this study was to determine beneficial effect of boron on nutrient utilization in buffalo calves exposed to high fluoride (F) ration. For this purpose, we used three groups of four male Murrah buffalo calves (body weight 98-100 kg, aged 6-8 month) each. Control animal was given only basal diet and concentrate mixture. However, treatment I animals were fed basal diet, concentrate mixture, and F [as NaF, 60 ppm of dry matter (DM)]. The treatment II animals were fed basal diet, concentrate mixture, F (as NaF, 60 ppm of DM), and B (as sodium tetraborate, 140 ppm of DM). After 90 days of experimental feeding, a metabolism trial of 7 days duration was conducted to study the treatment effect on nutrient utilization of proximate nutrients, absorption, excretion, and retention of N, Ca, P, Fe, Zn, Cu, and F. Dietary F significantly (p < 0.05) depressed the dry matter intake and increased the apparent digestibility, absorption, and retention of F. However, boron supplementation significantly (p < 0.05) decreased the apparent digestibility, absorption, and retention of F and improved the dry matter intake, fecal excretion, and percent of absorbed F excreted via urine. Apparent digestibility of proximate nutrients (viz. DM, crude protein, crude fiber, ether extract, and nitrogen free extract) was unaffected on either F or F+B treatment. However, absorption and excretion of N, Ca, P, Fe, Zn, and Cu were affected significantly (p < 0.05) on F or F+B treatment. These findings suggest that fluoride-containing diet for short duration has effect on nutrient utilization, and boron at 140-ppm dose level, in general, antagonized the absorption and retention of F and also improved the feed intake in buffalo calves.

Low-fluoride dentifrice and the effect of postbrushing rinsing on fluoride availability in saliva.

AIM: Post-brushing water rinsing may reduce the risk of fluoride (F) ingestion from dentifrice, however the decreased salivary F bioavailability may compromise any consequent anticaries benefits. As the use of low-F concentration dentifrices is still a matter of debate, a comparison was made between the salivary F bioavailability after brushing with a conventional F dentifrice followed by a water rinse and after brushing with a low-F dentifrice without post-brushing rinse. STUDY DESIGN AND METHODS: In a crossover, blind study, F concentration in saliva of 5 adult volunteers was determined after brushing with a low-F dentifrice (500 microg F/g) or with a conventional F concentration dentifrice (1100 microg F/g), followed or not by a 15-mL water rinse. RESULTS: Salivary F bioavailability was reduced by 2.5 times when a water rinse was used (p<0.05), irrespective of dentifrice concentration, and it was 2 times lower for the low-F dentifrice (p<0.05). The salivary F bioavailability was similar when the low-F dentifrice was used without post-brushing rinse and the conventional F dentifrice was followed by a rinse (p>0.05). CONCLUSION: Habits of post-brushing rinse should be taken into account on the recommendation of dentifrice use by young children, considering the risks and benefits balance of F use.

[Concentration of fluoride in mixed saliva of patients with end-stage renal disease undergoing renal replacement therapy]. / Stezenie fluorków w slinie mieszanej osób ze schylkowa niewydolnoscia nerek leczonych metodami nerkozastepczymi.

This study was carried out on 48 patients with ESRD undergoing hemodialysis treatment (29 males and 19 females, mean age 50.8 years) and renal transplantation (15 females and 33 males, mean age 42.2 years). The results were compared with a group of 44 healthy persons (23 females and 21 males, mean age 49.5 years). The aim of our investigation was to examine the content of fluoride in the mixed unstimulated saliva of the patients undergoing renal replacement therapy and in the control group of healthy persons. We studied the influence of hemodialysis on saliva fluoride levels. Saliva samples were collected by the spitting method according to Navazesh. Samples were collected before and after hemodialysis session and once in graft recipients and controls. Fluoride concentrations were determined with an Orion fluoroselective electrode model 96-09. The fluoride level in healthy persons was 4.92 +/- 2.30 micromol/L. Before hemodialysis, the mean fluoride level was 9.63 +/- 3.90 micromol/L and decreased significantly to 7.52 +/- 2.71 micromol/L after hemodialysis (p < 0.0001). Saliva content of fluorides in patients before and after hemodialysis was significantly higher than in healthy subjects and kidney graft recipients (p < 0.0001). There was no significant difference in fluoride concentration between patients after kidney transplantation and controls. The results suggest the need for individual fluoride supplementation in chronically hemodialysed patients.

The choice of controls in toothpaste studies. The effect of a number of commercially available toothpastes compared to water on 4-day plaque regrowth.

Toothpastes have been shown to have an antimicrobial activity both in vitro and in vivo; this activity variably translates into a plaque inhibitory effect in vivo. Commercially available toothpastes have a complex chemical make-up and some contain additional chemicals for which improved effects against plaque have been claimed. The aim of this study was to assess the plaque inhibitory properties of 5 commercially available toothpastes compared to a rinse of water over 4 days. The study was a randomised, single-blind, cross-over design balanced for residual effects. Volunteers were rendered plaque-free at each baseline and rinsed for 1 min, under the supervision of an assistant, 2x a day with the allocated mouthrinse or toothpaste slurry. At the end of the 4-day test period, the plaque was disclosed and measured by plaque index and plaque area. The plaque measurements indicated a significant difference between the toothpastes. The order of efficacy was Colgate Total, Crest regular, Crest Tartar, Colgate regular, Colgate 0-6 gel and water. This confirms previously reported data confirming the plaque inhibitory properties of certain toothpastes compared to water. These data indicate that the choice of control toothpaste with which to compare toothpastes formulated for plaque control is important and could influence conclusions drawn from clinical trials of such products.

Effect of post-brushing water rinsing on caries-like lesions at approximal and buccal sites.

The aim was to study the effect of two different water rinsing procedures after toothbrushing with an NaF-containing dentifrice on the degree of de- or remineralization of enamel and dentine at approximal and buccal sites. Seven adults, wearing complete dentures, participated in two experimental periods (A and B) in a randomised order. During period A, they brushed with the dentifrice for 2 min, followed by 1-min active mouthrinse with the toothpaste-foam combined with 10 ml of water. No more water was used after the slurry had been spat out. During period B, the brushing was followed by 3 thorough rinsings of approximately 15 ml water each. These two procedures were carried out twice daily, i.e. in the morning (after breakfast) and in the evening (just before bedtime), during 3 months. Demineralized enamel and dentine samples were mounted at two locations--approximally and buccally--in the first molar region of the upper prostheses. Quantitative microradiography (TMR) was used to assess the lesion depth (ld) and the mineral loss (delta Z). The results showed that the approximally located samples continued to lose mineral during both periods A and B. However, the ld and delta Z values for enamel (p < 0.01) and dentine (p < 0.05) increased less during A than B. The buccally located enamel and dentine samples remineralized during the experiment, but no statistically significant differences were found for the ld and delta Z values of either enamel or dentine between periods A and B.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction of vitamin A deficiency and excess fluoride in calcification of rat bones and teeth.

Using a 2 X 2 factorial design, we evaluated the possible interaction of vitamin A deficiency and excess fluoride in rat dentin and bone. Simultaneous presence of excess fluoride plus vitamin A deficiency resulted in a significant decrease in bone fluoride concentration compared to the presence of excess fluoride alone. Vitamin A deficiency alone significantly reduced calcium concentration in dentin formed during the deficient period.