Salivary fluoride bioavailability after use of high-fluoride dentifrices with different compositions: A short-term randomized clinical trial.

OBJECTIVE: The objective of the study was to evaluate the kinetics of salivary F bioavailability after the use of high-fluoride dentifrices with different compositions and their amount of total soluble fluoride (TSF). METHODS: A short-term clinical randomized trial was performed in which 15 adult participants were randomly allocated into three groups: 5000 ppm F-dentifrice, 5000 ppm F-dentifrice + TCP (tri-calcium phosphate) and 1450 ppm F-dentifrice. Unstimulated saliva was collected at different times: baseline (before toothbrushing), immediately after brushing/water rinsing and at 5, 15 and 30 min and 1, 2, 4, 8 and 12 h after brushing. The TSF in dentifrices and saliva samples was analysed using an ion-specific electrode. For statistical analysis, the paired t-test and Kruskal-Wallis were used with Dunn's post-test with a 95% confidence interval. RESULTS: There was no significant difference between the declared TSF and that found in 5000 ppm F-dentifrice and 1450 ppm F-dentifrice (p ≥ 0.13); however, in the 5000 ppm F-dentifrice + TCP, approximately 500 ppm less TSF was observed (p = 0.0024). The area under the curve (AUC, µg F/ml min-1 ) of both high-fluoride dentifrices (321.7 ± 84.0 and 223.6 ± 55.1 for the one without and with TCP, respectively) was higher than the conventional one (89.97 ± 15.6) attesting a higher F-bioavailability (p = 0.04). Furthermore, they were able to provide F-salivary levels higher than the baseline for up to 2 h, while this time was 1 h for the 1450 ppm F-dentifrice (p ≤ 0.003). CONCLUSION: Both high-fluoride dentifrices similarly increased the salivary-F bioavailability in comparison with 1450 ppm F-dentifrice, despite the lower TSF presented by the dentifrice containing TCP.

Effect of high-fluoride dentifrice on root dentine and bacterial composition in a multispecies biofilm model.

The present study evaluated the effect of high-fluoride dentifrice on dentine demineralization and bacterial composition in a multispecies biofilm model in vitro. A seven-organism bacterial consortium was grown on bovine dentine discs in a high-throughput active attachment model. The biofilms were submitted twice per day to the following dentifrices treatments: 5,000 ppm F, 1,100 ppm F, with placebo as a negative control. After 5 days of biofilm growth, dentine samples were assessed by transversal microradiography, the biofilm was collected for bacterial counts and the pH of the media was determined. Lower integrated mineral loss values were observed when 5,000 ppm F-treatment was used compared to the other treatments. Overall microbiological counts decreased with increasing F-concentration as well the pH of the media throughout the experiment. The 5,000 ppm F-treatment caused a shift in microbial composition and reduced dentine demineralization in the in-vitro experimental model.

Chemokines and cytokines profile in whole saliva of patients with periodontitis.

Clinical features suggest differences in immune response among periodontitis forms, albeit a large number of cytokines and chemokines remain to be evaluated. The saliva is an available source of mediators and its analysis would be valuable in order to understand pathophysiological differences. The objective of this study was analyze chemokines/cytokines profile in whole saliva of individuals with severe periodontitis (Stage III) presenting moderate [Grade B; GB] or rapid progression rate with a localized incisor-molar pattern [Grade C; GC/IMP]. A case-control study was designed for each periodontitis group. GB (n = 9) and GC/IMP (n = 7) patients and their healthy controls (C-GB, n = 9 and C-GC, n = 7) were evaluated. Non-stimulated saliva samples were assessed by a multiplex assay for a total of 40 cytokines, C-C and C-X-C motif chemokines. GC/IMP group presented higher levels of CCL17 and CCL27 (p = 0.04, FDR > 0.05), and lower levels of CCL2 (p = 0.04, FDR > 0.05) and CCL25 (p = 0.006, FDR < 0.05) when compared to its control. GB patients had higher levels of IL-6, IL-1ß (p = 0.04, FDR > 0.05), and elevated pro-inflammatory (TNF-α,IL-1ß,INF-γ,IL-6, IL-16): anti-inflammatory (IL-2, IL-4, IL-10) ratio (p = 0.01, FDR < 0.05) compared to its control [p-values by Mann-Whitney test, and False Discovery Rate (FDR) by Benjamini-Hochburg corrections]. CCL-chemokines and cytokines contributed to differences between GC/C-GC and GB/C-GB, respectively (p < 0.05, PERMANOVA test). These preliminary data revealed that each periodontitis phenotype presented distinct immune profiles differentially expressed in saliva compared to their related controls, suggesting differences in the etiopathogenesis of GB and GC/IMP.

Effect of high-fluoride dentifrice and bracket bonding composite material on enamel demineralization in situ.

OBJECTIVE: This in situ study evaluated the effect of high-fluoride dentifrice (5000 µg F-/g) and fluoride-containing bonding composite resin on enamel demineralization adjacent to orthodontic brackets. METHODS: Ten volunteers wore palatal appliances containing bovine enamel blocks with metallic brackets bonded with fluoride-free or fluoride-containing composite resin. During three phases of 14 days each, three dentifrices with different fluoride concentrations (0, 1100, and 5000 µg F-/g) were tested. The cariogenic challenge consisted of 20% sucrose solution dripped 8x/day onto the dental blocks. At the end of each phase, biofilm formed was collected for fluoride analysis. Cross section hardness was performed in enamel blocks, and the lesion area was calculated. Data were analyzed by two-way ANOVA followed by Tukey post hoc test (α = 5%). RESULTS: The only signicant factor for all the variables under study was the dentifrice. Smaller lesion area and higher fluoride concentration on biofilm were found in 5000 µg F-/g group, irrespective of bonding composite resin (p < 0.001). Neither bracket-bonding composite resin nor the interaction between the factors was statistically significant (p > 0.05) for all the variables. CONCLUSION: High-fluoride dentifrice is effective in reducing demineralization on enamel adjacent to orthodontic brackets, while the fluoride-containing bonding composite resin does not influence it. CLINICAL SIGNIFICANCE: Since high-fluoride dentifrice was able to reduce demineralization adjacent to brackets, it can be an option to caries management in orthodontics patients.

Salivary fluoride levels after use of high-fluoride dentifrice.

The aim of the study was to evaluate salivary fluoride (F) availability after toothbrushing with a high-F dentifrice. Twelve adult volunteers took part in this crossover and blind study. F concentration in saliva was determined after brushing with a high-F dentifrice (5000 µg F/g) or with a conventional F concentration dentifrice (1100 µg F/g) followed by a 15 mL distilled water rinse. Samples of nonstimulated saliva were collected on the following times: before (baseline), and immediately after spit (time = 0) and after 1, 2, 3, 4, 5, 10, 15, 20, 30, 45, 60, 90, and 120 min. F analysis was performed with a fluoride-sensitive electrode and the area under curve of F salivary concentration × time (µg F/mL × min(-1)) was calculated. At baseline, no significant difference was found among dentifrices (P > 0.05). After brushing, both dentifrices caused an elevated fluoride level in saliva; however salivary F concentration was significantly higher at all times, when high-F dentifrice was used (P < 0.01). Even after 120 min, salivary F concentration was still higher than the baseline values for both dentifrices (P < 0.001). High-F dentifrice enhanced the bioavailability of salivary F, being an option for caries management in patients with high caries risk.

Lactobacilli Probiotics Modulate Antibacterial Response Gene Transcription of Dendritic Cells Challenged with LPS.

Probiotics are beneficial bacteria that may modulate the immune response by altering the maturation and function of antigen-presenting cells, such as dendritic cells. This study aimed to evaluate the antibacterial gene expression of dendritic cells challenged with LPS and probiotics. Immature dendritic cells were obtained from human CD14+ monocytes and challenged with E. coli LPS and probiotics Lacticaseibacillus rhamnosus (LR-32) and Lactobacillus acidophilus (LA-5) at a ratio DC:bacteria of 1:10. The analysis of gene expression was performed by RT-qPCR using the Kit RT2 human antibacterial response. In the supernatant, the cytokines secretion was determined by ELISA. Tukey post-ANOVA with p at 5% was used for statistical analysis. LPS showed the higher upregulation of 29 genes compared with the groups where probiotics were added to LPS, including genes related to an inflammatory response like BIRC3, CASP1, CCL5, CXCL1, IL12B, IL18, MYD88, NLRP3, RIPK1, and TIRAP. Similarly, LPS increased the transcription of genes enrolled with apoptosis such as CARD6, CASP1, IRF5, MAP2K1, MAP2K4, MAPK1, MYD88, NLRP3, RIPK2, TNF, TNFRSF1A, and XIAP when compared to probiotics groups (p < 0.05). Although probiotics decrease several genes upregulated by LPS, the transcription of encoded cytokines IL12A, IL12B, IL1B, IL6, CXCL8, and TNF genes was maintained upregulated by probiotics, except for IL18, which was downregulated by LA-5. LA-5 led to a higher transcription of IL1B, IL6, and CXCL-8 which was followed by the secretion of these proteins by ELISA. The results suggest that probiotics attenuate the transcription of inflammatory and immune response genes caused by LPS.

Chemical Characterization and Effect of a Lactobacilli-Postbiotic on Streptococcus mutans Biofilm In Vitro.

Postbiotic is the term used to define the soluble factors, metabolic products, or byproducts released by live probiotic bacteria or after its lysis. The objective of this study was to carry out the chemical characterization of the postbiotic of Lacticaseibacillus rhamnosus LR-32 and to evaluate its in vitro effect on the development of the Streptococcus mutans biofilm. After the cultivation of the probiotic strain, the postbiotic was extracted by centrifuging the culture and filtering the supernatant. This postbiotic was characterized by using gas chromatography coupled with mass spectrometry (GC-MS), and then it was used to determine the growth inhibition of S. mutans in its planktonic form; additionally, its effects on the following parameters in 48 h biofilm were evaluated: viable bacteria, dry weight, and gene expression of glucosyltransferases and VicR gene. The control group consisted of the biofilm without any treatment. A paired t-test was performed for statistical analysis, with the p-value set at 5%. Seventeen compounds of various chemical classes were identified in the postbiotic, including sugars, amino acids, vitamins, and acids. The treatment with the postbiotic led to an inhibition of the growth of S. mutans in its planktonic form, as well as a decrease in the number of viable bacteria, reduction in dry weight, and a negative regulation of the gene expression of gtfB, gtfC, gtfD, and vicR in its biofilm state, compared with the nontreated group (p < 0.05). The postbiotic of L. rhamnosus impaired the development of S. mutans biofilm.

Effect of Probiotics Lactobacillus acidophilus and Lacticaseibacillus rhamnosus on Antibacterial Response Gene Transcription of Human Peripheral Monocytes.

Periodontitis and related systemic inflammatory diseases are characterized by imbalanced ratio between pro- and anti-inflammatory factors. Probiotics may control inflammation by altering the inflammatory phenotype of defense cells. We aimed to evaluate the gene transcription of the antibacterial response of monocytes to exposure to probiotic lactobacilli. CD14 + monocytes were obtained by positive selection from peripheral blood mononuclear cells from healthy donors (5 × 104 CD14 + /mL) and cultured with probiotic strains of Lacticaseibacillus rhamnosus (LR-32) and Lactobacillus acidophilus (LA-5) at a 1:10 multiplicity of infection in 24-well plates for 12 h. The gene expression analysis was performed by RT-qPCR using the Kit RT2 human antibacterial response, and in the supernatant, the cytokines were determined by ELISA. Tukey's post hoc test following an ANOVA with a p value of 5% was used for statistical analysis. Both probiotic strains increased the levels of cytokines TNF-α and CXCL-8 in the supernatant compared to the control of non-challenged cells (p < 0.05), but for IL-1Β and IL-6, this effect was observed only for LA-5 (p < 0.05). The fold-regulation values for the following genes for LA-5 and LR-32 were, respectively, IL-12B (431.94 and 33.30), IL-1Β (76.73 and 17.14), TNF-α (94.63 and 2.49), CXCL-8 (89.59 and 4.18), and TLR-2 (49.68 and 3.40). Likewise, most of the other genes evaluated showed greater expression for LA-5 compared to LR-32 (p < 0.05). The positive regulation of inflammatory factors such as IL-1ß promoted by L. acidophilus LA-5 may increase the antibacterial activity of innate defense in periodontal tissues. However, this property may be deleterious by increasing inflammatory response.

Nocturnal Salivary Fluoride Bioavailability After Brushing with a High-fluoride Dentifrice.

The use of fluoridated dentifrices is recognized as the main reason for the decline of dental caries and its effect is associated with the bioavailability of fluoride (F) in the oral cavity. High-fluoride dentifrice has been indicated for patients at high risk of caries and management of root lesions. This study aimed to evaluate the bioavailability of F in saliva after the use of high-fluoride dentifrice during the nocturnal period. Fifteen healthy adults participated in this is in vivo and crossover study in which the concentration of F in their saliva was determined after brushing with the tested dentifrices: a conventional (1450 ppm F) or with high-fluoride concentration (5000 ppm F). Before brushing, the participants collected the non-stimulated saliva (baseline), immediately after brushing (time zero) and after 5min, 2h, 4h, and 8h, during the nocturnal period (between 10:00 pm and 06:00 am). The salivary F concentration was determined using a specific F ion electrode. Regarding statistical analysis, a paired t-test was used to compare dentifrices with p fixed at 5%. At baseline, there was no significant difference between groups (p>0.001). Immediately after brushing, both dentifrices increased the F salivary concentration, with the highest concentration reached in time zero; however, the use of 5000 ppm F dentifrice maintained the higher F salivary concentration at all times evaluated (p<0.001), remaining higher until 8 h after brushing. Furthermore, this treatment showed higher F bioavailability in relation to time, evaluated by the area under the curve (p<0.001). Thus, it can be concluded that the high-fluoride dentifrice increased the bioavailability of salivary F during the nocturnal period in comparison with conventional dentifrice.

Effect of probiotic Lactobacillus rhamnosus by-products on gingival epithelial cells challenged with Porphyromonas gingivalis.

OBJECTIVE: Probiotics are usually given as living cells, but their effects may be also achieved by postbiotics. We hypothesized that probiotics products (spent media and lysate) altered the response induced by P. gingivalis in gingival epithelial cells (GECS). METHODS: Immortalized human OBA-9 GECs (∼2,5 × 105cells/well) were challenged with P. gingivalis ATCC33277, and co-infected with L. rhamnosus Lr-32 for 4 h. L. rhamnosus Lr-32 spent medium or cells lysate was added to GECs co-infected with P. gingivalis. Another set of OBA-9 GECs were first exposed to P. gingivalis ATCC 33277 and then to the living probiotic or probiotic products. Transcription of genes encoding inflammatory mediators (IL-1ß, TNF-α, IL-6, and CXCL-8) and receptors (TLR2 and TLR4) were evaluated by RT-qPCR. P. gingivalis growth under L. rhamnosus Lr-32 postbiotics was also evaluated. RESULTS: L. rhamnosus Lr-32 spent media decreased cell viability, while living cells and cell lysates did not. L. rhamnosus Lr-32 lysate, but not spent media, upregulated transcription of inflammatory mediators (IL-1ß, TNF-α, IL-6, and CXCL-8) in GECs infected with P. gingivalis. Transcription of TRL2 was upregulated in all experimental groups compared to control, whereas TLR4 was upregulated by the probiotic or its postbiotics in P. gingivalis infected cells. Spent media and lysates reduced the growth of P. gingivalis. CONCLUSION: L. rhamnosus Lr-32 cell components rather than live probiotic enhanced the expression of inflammatory mediators in P. gingivalis infected gingival epithelial cells. The increased potential of Lr-32 cell lysates to promote immune response to the periodontopathogen may favor pathogen elimination but may also lead to additional deleterious effects of the exacerbated inflammation.

Development of an Experimental Dentifrice with Hydroxyapatite Nanoparticles and High Fluoride Concentration to Manage Root Dentin Demineralization.

BACKGROUND: High-fluoride dentifrice is used to manage root caries, but there is no evidence whether its association with nanohydroxyapatite could provide an additional protection for root caries. Therefore, this study aimed to develop and evaluate the effect of an experimental dentifrice with high fluoride (F-) concentration and nanohydroxyapatite (nano-HA) on root dentin demineralization. MATERIALS AND METHODS: After formulation of dentifrices, root dentin specimens were randomly assigned to six groups (n = 10) using different dentifrice treatments: placebo; nano-HA without F-; 1,100 µg F-/g; 1,100 µg F-/g + nano-HA; 5,000 µg F-/g; and 5,000 µg F-/g + nano-HA. A pH cycling model was performed for 10 days, in which treatments were performed twice a day. After that period, the longitudinal hardness was evaluated and the area of demineralization (ΔS) was calculated. The formulated dentifrices were evaluated for primary stability, cytotoxicity, and other technical parameters. Two-way ANOVA and Tukey's test with p set at 5% were used for data analysis. RESULTS: The experimental dentifrices were stable and had no cytotoxicity. Regarding dentin demineralization, the placebo group significantly increased ΔS compared to all other treatment groups (p<0.001). The dentifrices containing 5,000 µg F-/g, regardless of the presence of nano-HA, led to a smaller lesion area in relation to the other treatments (p<0.001). CONCLUSION: The findings of this study suggest that nano-HA reduced dentin demineralization, and dentifrice with 5,000 µg F-/g dentifrices, regardless of the presence of nano-HA, showed a greater reduction in root dentin demineralization.

Fluoride Release of Fresh and Aged Glass Ionomer Cements after Recharging with High-Fluoride Dentifrice.

OBJECTIVE: This study aimed to evaluate F release from GICs before and after recharging with F-dentifrices and after aging process. METHODS: Fifteen specimens of GICs (conventional, resin modified, and high viscosity) and composite resin were stored individually in a polystyrene tube containing 2 ml of deionized water (DW), with water replacement every 24 hours. After 15 days, the specimens were treated with a dentifrice suspension (1 : 3 by volume) containing 0 µg F/g (n = 5), 1,100 µg F/g (n = 5), or 5,000 µg F/g (n = 5). After 3 min, the specimens were rinsed and replaced in new tubes with 2 ml of DW. This procedure was performed 2x/day for 2 days. The readings were taken on days 1, 5, 10, and 15 before and after the treatments. A second experiment was performed, using the same specimens of the previous study that were submitted to an aging process (specimens were kept in 2 ml of DW, remaining at 37°C for 36 weeks). Readings using specific electrode for F detection were taken on days 1, 5, 10, and 15 after treatment of the samples as described above. Data were analyzed by ANOVA and Tukey's test with α fixed at 5%. RESULTS: It was observed that the highest release of F for all the GICs occurred on the first day after the treatments, especially when using a high-fluoride dentifrice, with decreasing release over time. Also, although aged GICs still recharge with F treatments, the amount of F released was lower than fresh materials. CONCLUSION: GICs present a high F recharge and release capacity, especially in the first 24 hours and after the treatment with a high-fluoride dentifrice, even after material aging.

Is the fluoride intake by diet and toothpaste in children living in tropical semi-arid city safe?

Data about total fluoride intake in children living in a tropical semi-arid climate city is scarce, thus we conducted this study. Fifty-eight children aged two to five years, living in a Brazilian tropical city with optimally fluoridated water were selected. Dietary samples were collected using the duplicate diet method on two non-consecutive days in the children's home toothpaste was determined by subtracting the amount of fluoride recovered after brushing from the amount placed on the toothbrush. The mean total dose (SD) of fluoride intake was 0.043(0.016) mg F·kg-1·d-1, with the major (60.6%) contribution from water. The factors associated with the ingestion of fluoride from toothpaste were fluoride concentration of the toothpaste (p = 0.03) and the use of kids toothpaste (p = 0.02). The findings suggest that children have a low fluoride intake, measured by at-home meals and use of fluoride toothpaste; drinking water is the main source of fluoride ingestion.

Effect of Mouthwashes on Solubility and Sorption of Restorative Composites.

OBJECTIVE: Composites sorption and solubility can be precursors of several chemical and physical processes, which lead to deleterious effects on the polymer structure. This study evaluated the effect of mouthwashes on solubility and sorption of composite resins. MATERIALS AND METHODS: Forty-two specimens of each evaluated composite (Filtek Bulk Fill Flow, Opallis Flow, Durafill VS, and Filtek Z350) were prepared and randomized into seven groups for each solution (mouth rinses with and without alcohol and distilled water) and stored for seven days. Solubility and sorption tests were performed according to ISO4049. Data were analyzed using 2-way-ANOVA followed by Tukey's test for means comparison (α = 0.05). In addition, paired t-test was performed to analyze the alcohol effect on the studied composite resin properties. RESULTS: Listerine Cool Mint (containing alcohol in its composition) caused the greatest degree of sorption for all composites tested in comparison to other rinses, while for solubility this behavior was observed for Opallis Flow and Durafill VS composite resins (p < 0.05). Regarding the composites, Opallis Flow showed the highest sorption and solubility values in general (p < 0.05). CONCLUSION: Overall, the sorption and solubility of composites were higher in mouthwashes containing alcohol in its composition, with Opallis Flow being the most affected composite resin.

Recolonization of mutans Streptococci after application of chlorhexidine gel.

Streptococcus mutans is specifically suppressed by intensive treatment with chlorhexidine gel, but the time for recolonization and the effect on other oral bacteria are not totally clear. In this study, recolonization of mutans streptococci was evaluated in nine healthy adult volunteers, who were highly colonized with this microorganism. Stimulated saliva was collected before (baseline) and at 1, 7, 14, 21 and 28 days after application of 1% chlorhexidine gel on volunteers' teeth for two consecutive days. On each day, the gel was applied using disposable trays for 3 x 5 min with intervals of 5 min between each application. Saliva was plated on blood agar to determine total microorganisms (TM); on mitis salivarius agar to determine total streptococci (TS) and on mitis salivarius agar plus bacitracin to determine mutans streptococci (MS). Chlorhexidine was capable of reducing the counts of MS and the proportion of MS with regard to total microorganisms (%MS/TM) (p<0.05), but these values did not differ statistically from baseline (p>0.05) after 14 days for MS and 21 days for %MS/TM. The counts of TM and TS and the proportion of MS to total streptococci did not differ statistically from baseline (p>0.05) after chlorhexidine treatment. The results suggest that the effect of chlorhexidine gel treatment on suppression of mutans streptococci is limited to less than a month in highly colonized individuals.

Effect of Sweeteners on Root Dentine Demineralization Using a Microcosm Biofilm Model / Efecto de los Edulcorantes en la Desmineralización de la Dentina Radicular Utilizando un Modelo de Biofilm Microcosmo

ABSTRACT: The aim of the present study was to evaluate the effect of commercial sweeteners on root dentin demineralization using a microcosm biofilm model. Bovine dentin specimens with pre-determined surface hardness were randomized into six groups according to the studied sweeteners: sucralose, stevia, saccharin, aspartame. Sucrose was used as a positive control and an untreated group as a negative control. The specimens were submitted to biofilm development from one saliva donor and the cariogenic challenge occurred on subsequent five days, twice a day. At the end, the percentage of surface hardness loss (%SHL) and biomass was determined and submitted to ANOVA followed by Tukey's test. Sucrose presented the highest rate of demineralization, however, all sweeteners tested lead to a statistically higher root demineralization compared to the negative control (p <0.05). Sucrose caused greater demineralization in root dentin, however, the sweeteners were also able to induce it under this biofilm model.

RESUMEN: El objetivo del presente estudio fue evaluar el efecto de los edulcorantes comerciales en la desmineralización de la dentina radicular utilizando un modelo de biofilm microcosmo. Se asignaron al azar muestras de dentina bovina con una dureza de la superficie predeterminada de acuerdo con los edulcorantes estudiados: sucralosa, estevia, sacarina, aspartame. La sacarosa se utilizó como control positivo y un grupo no tratado como control negativo. Las muestras se enviaron al desarrollo de biopelículas de un donante de saliva y el desafío cariogénico se produjo en los siguientes cinco días, dos veces al día. Al final, se determinó el porcentaje de pérdida de dureza de la superficie (% PDS) y biomasa y se aplicó un estudio estadístico de ANOVA seguido de la prueba de Tukey. La sacarosa presentó la mayor tasa de desmineralización; sin embargo, todos los endulzantes probados condujeron a una desmineralización de la raíz estadísticamente mayor en comparación con el control negativo (p<0,05). La sacarosa causó una mayor desmineralización en la dentina de raíz, sin embargo, los edulcorantes también fueron capaces de inducirla bajo este modelo de biofilm.

Is the fluoride intake by diet and toothpaste in children living in tropical semi-arid city safe?

Abstract: Data about total fluoride intake in children living in a tropical semi-arid climate city is scarce, thus we conducted this study. Fifty-eight children aged two to five years, living in a Brazilian tropical city with optimally fluoridated water were selected. Dietary samples were collected using the duplicate diet method on two non-consecutive days in the children's home toothpaste was determined by subtracting the amount of fluoride recovered after brushing from the amount placed on the toothbrush. The mean total dose (SD) of fluoride intake was 0.043(0.016) mg F·kg-1·d-1, with the major (60.6%) contribution from water. The factors associated with the ingestion of fluoride from toothpaste were fluoride concentration of the toothpaste (p = 0.03) and the use of kids toothpaste (p = 0.02). The findings suggest that children have a low fluoride intake, measured by at-home meals and use of fluoride toothpaste; drinking water is the main source of fluoride ingestion.

Sucrose induced dentin demineralization in a microcosm biofilm model / Desmineralización de la dentina inducida por sacarosa en un modelo de biofilm microcosmo

The aim of this in vitro study was to assess the root dentin demineralization caused by a microcosm biofilm model that has been exposed to sucrose in different ways. Materials and Methods: Saliva of two volunteers was inoculated into an artificial medium for biofilm growth and dentin blocks were immersed into these media. Dentin specimens were randomly exposed to one of the five experimental conditions: C (control group - no saliva inoculum or sucrose), 0S (saliva inoculum without sucrose, negative control), 3S (three daily one-minute immersions in 20 % sucrose), 6S (six daily one-minute immersions in 20 % sucrose), and CS (continuously immersed in 5 % sucrose). After five days, biofilm was collected to determine the concentration of intracellular and extracellular polysaccharides and the dentin surface hardness loss (SHL) was measured. The experiment was carried out in triplicate. Results: The dentin SHL was higher in groups that were exposed to sucrose (3S, 6S and CS) and there was a statistically significant difference between all groups (p<0.001). CS had higher concentrations of polysaccharides (p>0.001) and there was no statistically significant difference between the other groups (0S, 3S and 6S) (p>0.005). Conclusion: The microcosm biofilm model developed has the potential to produce root dentin demineralization at different exposures to sucrose.

El objetivo de esta investigación in vitro fue evaluar la desmineralización de la dentina radicular causada por un modelo de biofilm microcosmo que fue expuesto de diferentes maneras a la sacarosa. La saliva de dos voluntarios fue colocada en un medio artificial para crecimiento del biofilm y los bloques de dentina fueron sumergidos en estos medios. Al aza rlos bloques fueron expuestos a una de las cinco condiciones experimentales: C (grupo control ­ sin inoculación de saliva o sacarosa), 0S (inoculación de saliva sin sacarosa, control negativo), 3S (tres inmersiones diarias de un minuto en sacarosa a 20 %), 6S (seis inmersiones diarias de un minuto en sacarosa a 20 %), y CS (sumergidos continuamente en 5 % de sacarosa). Después de cinco días, el biofilm fue recogido para determinar la concentración de polisacáridos intracelulares y extracelulares y fue medida la pérdida de dureza superficial de la dentina (SHL). El experimento se repitió en tres ocasiones. La dentina SHL era mayor en los grupos que fueron expuestos a la sacarosa (3S, 6S E CS) y hubo diferencia estadísticamente significativa entre todos los grupos (P<0,001). CS presentó mayor concentración de polisacáridos (p<0,001) y no hubo diferencia estadísticamente significativa entre los demás grupos (0S, 3S E 6S) (p>0,005). El modelo del biofilm desarrollado tiene potencial para producir desmineralización de la dentina radicular en diferentes exposiciones a la sacarosa.

Association of chlorhexidine and high fluoride dentifrice on Streptococcus mutans viability using an in vitro biofilm model / Associação de clorexidina e dentifricio com alta concentração de flúor na viabilidade de Streptococcus mutans em um modelo de biofilmes in vitro

Objective: this in vitro study investigated the effect of high-fluoride dentifrice, Chlorhexidine (CHX), and their association on the viability of Streptococcus mutans using a biofilm model. Material and Method: biofilms were anaerobically grown on glass slides that were vertically suspended in 24-well plates for 5 days. After 48 h of initial growth, biofilms were treated for the next 72 h, 2x/day with 0.12% CHX and 2%, F as 0.08% and 0.4% NaF and their association. Results: CHX treatment decreased the bacteria counts either alone or in association with both F concentrations, when compared with control group and the F treatments alone (p < 0.05). Conclusion: no additional effect was observed when CHX and F were used in combination, when compared with CHX used alone.

Objetivo: este estudo avaliou, o efeito do dentifrício com alta concentração de fluor (F), da clorexidina (CHX) e da associação destes na viabilidade de Streptococcus Mutans (SM) utilizando um modelo de biofilme in vitro. Materiais e Métodos: biofilme cresceram anaerobicamente em lamínulas de vidro suspensas, verticalmente, em placas de 24 poços por 5 dias. Após 48h do crescimento inicial, o biofilme formado foi submetido a um tratamento por 72h, 2x/ dia com CHX 0.12%, F na forma de NaF a 0.08% e 0.4%, suas associações, CHX 2% (controle positivo) e solução salina (controle negativo). Os dados obtidos foram transformados e submetidos ao ANOVA e teste de Tukey e em seguida analisados por meio do SAS, com significância fixada em 5%. Resultados: isolada ou em associação com as diferentes concentrações de F, a CHX demonstrou maior potencial em reduzir os níveis de SM quando comparada ao uso isolado de F em ambas concentrações ou com o controle negativo (p < 0,05). Conclusão: o uso da combinação de F e CHX não apresentou efeito adicional na redução dos níveis de SM quando comparado ao uso isolado de CHX.

Candida spp. in complete dentures of institutionalized elderly individuals / Candida spp. en prótesis dentales totales de personas mayores institucionalizadas

The objective of this study was to evaluate the prevalence of Candida spp. in complete dentures of institucionalized elderly, aged 60 or more, in a city of northeast of Brazil. A survey was conducted of the health profile and quantification of Candida spp. from isolation in Sabouraud agar. Our results showed that from 181 institutionalized elderlies, only 17 (66-84 years) met the inclusion criteria. 47.1 % were totally dependent, and 58.8 % needed help with hygiene. The most commonly used drugs were antihypertensive. The results showed a high prevalence of Candida spp. (64.5 %) in the dentures of institutionalized elderly and this may be a reflection of poor oral hygiene.

El objetivo fue asociar el uso de prótesis dentales totales y la prevalencia de Candida spp. en ancianos institucionalizados con 60 o más años de edad, en una ciudad del Nordeste de Brasil. Se llevó a cabo un estudio del perfil de salud y cuantificación de Candida spp. por aislamiento con agar Sabouraud. A partir de 181 ancianos institucionalizados, sólo 17 (66­84 años) cumplieron los criterios de inclusión. 47,1 % eran totalmente dependientes y 58,8 % necesitó ayuda con la higiene. Los fármacos más utilizados fueron antihipertensivos. Los resultados mostraron una alta prevalencia de Candida spp. (64,5 %) en las prótesis dentales totales de los ancianos institucionalizados y esto tal vez sea un reflejo de la deficiente higiene oral.