Optimization of a Validated Protocol That Determines Bioavailable Fluoride in Toothpastes.

A validated protocol used to determine how much of total fluoride is bioavailable in toothpaste formulations was evaluated if it could be simplified regarding the following parameters: (1) concentration of the slurry (0.25-4%), (2) centrifugation speed (1,000-12,000 g) and time (1-10 min), and (3) incubation time for FPO32- ion hydrolysis and insoluble-F dissolution (15-60 min). Fresh and aged Na2FPO3/CaCO3 and fresh NaF/SiO2-based toothpastes were analyzed (n = 9). The improvements were the centrifugation at 1,000 g for 5 min is enough to separate insoluble-F and the time for FPO32- ion hydrolysis and insoluble-F dissolution can be shortened to 30 min.

Sugar intake above international recommendations and oral disease burden: A population-based study.

OBJECTIVE: To evaluate the association between added sugar intake above the daily limit for the risk of noncommunicable diseases (NCDs) and the Chronic Oral Disease Burden in adolescents. METHODS: This was a population-based study using cross-sectional data nested to RPS Cohorts Consortium, São Luís, Brazil, from the 18-19-year-old follow-up (n = 2515). High consumption of added sugars was estimated according to the limits of the World Health Organization guidelines (WHO) (≥5% of total energy/day) and the American Heart Association statement (AHA) (≥25 g/day). The Chronic Oral Disease Burden was a latent variable (number of decayed teeth, periodontal probing depth ≥4 mm, clinical attachment level ≥3 mm, and bleeding on probing). Models were adjusted for Socioeconomic Status, sex, obesity, and plaque index and analyzed through structural equation modeling. RESULTS: Adolescents had high sugar consumption according to the WHO (78.6%) and AHA (81.4%) recommendations. High sugar intake, according to WHO (SC = 0.096; p = 0.007) and AHA (SC = 0.056; p = 0.027), was associated with a heavier Chronic Oral Disease Burden. Even half of the recommended dose was sufficient to affect some oral disease indicators. CONCLUSION: Sugar intake over international statements to prevent NCDs is associated with higher Chronic Oral Disease Burden among adolescents.

Fluoride Formed on Enamel by Fluoride Varnish or Gel Application: A Randomized Controlled Clinical Trial.

Although fluoride varnish (FV) and acidulated phosphate fluoride gel (APF-gel) are considered clinically effective to reduce caries, in vitro studies have shown that FV reacts slowly with enamel because most NaF present in the formulation is not solubilized in the FV. Therefore, we conducted a clinical study to evaluate if the time that FV remains on dental surfaces could overcome its slower chemical reactivity when compared with APF-gel. Sixty-eight volunteers were randomly allocated into 4 groups: negative control (Control, no treatment), APF-gel application (1.23% F applied for 4 min), and FV application (Duraphat®, 2.26% F) for 4 h (FV-4h) or 24 h (FV-24 h). To evaluate fluoride formed and retained on enamel, acid biopsies were made on the buccal surfaces of the maxillary central incisors before, at the end of the application of fluoride products (immediately after gel application, or after 4 or 24 h of varnish application), and after 7 and 28 days. Fluoride concentration in dental biofilm was also analyzed before and up to 28 days after initial application. The data were analyzed by 2-way ANOVA, considering treatment and time as factors. The APF-gel and FV-24h groups formed greater fluoride concentration on enamel than the FV-4h and the control group at the end of application (p = 0.0001), with no difference from each other (p = 0.99). The groups did not differ regarding fluoride in biofilm fluid (p = 0.73) and solids (p = 0.40). In conclusion, FV needs to remain in contact with the teeth for prolonged times (>4 h) to reach the same reactivity obtained by a 4-min application of APF-gel.

Combination Effect of Diurnal Exposure to Sucrose and Nocturnal Exposure to Lactose on Enamel Demineralization.

We have hypothesized that the association between human milk and caries in breastfeeding children could be explained by the combination of a diurnal cariogenic diet with the nocturnal lactose fermentation, conditions simulated in this experimental study. Cariogenic biofilm was formed on bovine enamel slabs, which were exposed 8x/day for 3 min to a 10% sucrose solution, simulating a highly cariogenic diurnal diet, or 50 mM NaCl solution (control). Simulating the nocturnal retention of milk in mouth, biofilms were transferred to culture medium containing 0.7% lactose for 2 h, or only to culture medium (control). Four groups were designed (n = 12): Ctrl, no exposure to diurnal sucrose or nocturnal lactose; Lac, only nocturnal exposure to lactose (2 h); Suc, only diurnal exposure to sucrose (8x/day); and Suc→Lac, diurnal exposure to sucrose (8x/day) followed by nocturnal exposure to lactose (2 h). The medium was changed 3x/day, at the beginning of the day and after diurnal and nocturnal exposures. Calcium in the medium was determined as a chemical indicator of partial demineralizations occurred during the diurnal and the nocturnal treatments; the medium pH was also determined. After 96 h of growth, biofilms were harvested to evaluate CFU, biomass, and extracellular polysaccharides, soluble and insoluble. The percentage of enamel surface hardness loss (%SHL) was evaluated as cumulative demineralization. Data were analyzed by one-way ANOVA and Tukey's test (α = 5%). Highest %SHL (p < 0.05) was found for the Suc→Lac (40.6%) group when compared to Suc (32.1%), Lac (6.6%), and Ctrl (2.4%) groups. Calcium released during the diurnal and nocturnal treatments was, respectively, Suc→Lac = Suc > Lac = Ctrl and Suc→Lac > Lac > Suc = Ctrl (p < 0.05). Regarding the Ctrl group, calcium released from nocturnal lactose fermentation by the Suc→Lac group was 4-fold greater than that provoked by the Lac group. The findings were supported by the pH of the media. The data suggest that the biofilm formed under diurnal exposure to sucrose enhances the cariogenicity of nocturnal exposure to lactose.

Soluble Fluoride in Na2FPO3/CaCO3-Based Toothpaste as an Indicator of Systemically Bioavailable Fluoride.

Fluoride chemically soluble in toothpaste is an indicator of fluoride bioavailability when the teeth are brushed, and the same should be expected systemically when toothpaste is ingested. A 4-phases study was conducted, in which 8 participants were subjected in each phase to one of the assigned treatment groups: group I: fresh sample of a Na2FPO3/CaCO3 toothpaste with 1,334 µg F/g of total soluble fluoride (TSF) and groups II-IV: aged samples of toothpaste presenting TSF concentrations of 1,128, 808, and 687 µg F/g, respectively. In all phases, the participants ingested an amount of toothpaste equivalent to 70.0 µg F/kg body weight, as total fluoride (TF). Blood was collected before (baseline) and up to 180 min after toothpaste ingestion as indicator of fluoride bioavailability. Total urine (24 h before and 24 h after ingestion) was collected as indicator of absorbed fluoride that was excreted. F concentration in blood plasma and urine was determined with a fluoride ion-specific electrode. The areas under the curve (AUC) of F concentration versus time (AUC = ng F/mL × min) and the peaks of fluoride concentration in blood plasma (Cmax) were calculated. The net amount of fluoride excreted (mg/day) was calculated by subtraction. A significant correlation of the amount (mg) of TSF ingested was found between the AUC (r = 0.76; p < 0.01) and Cmax (r = 0.86; p < 0.01) in plasma, and the fluoride excreted (r = 0.65; p < 0.01). For TF, no statistical correlations were found (p > 0.05). Data suggest that the concentration of TSF found in Na2FPO3/CaCO3-based toothpastes is a useful predictor of how much fluoride will be systemically bioavailable when this type of formulation is ingested.

Fluoride Binding to Streptococcus mutans Pellets Rich in Extracellular Polysaccharides.

Extracellular polysaccharides (EPS), mainly the insoluble ones, increase the cariogenicity of dental biofilm, but whether they interfere with the binding and retention of fluoride is unknown. EPS-rich (EPS+) and EPS-poor (EPS-) pellets of Streptococcus mutans were formed and treated with increasing fluoride concentrations (0, 0.1, 1, or 10 mM). A concentration-dependent fluoride binding was observed in both EPS- and EPS+ pellets, but the presence of EPS did not affect the retention of fluoride in the pellets. In conclusion, the data suggest that a matrix of dental biofilm rich in EPS does not affect fluoride retention in the biofilm.

Chemically Soluble Fluoride in Na2FPO3/CaCO3-Based Toothpaste as an Indicator of Fluoride Bioavailability in Saliva during and after Toothbrushing.

The relationship between the concentration of chemically soluble fluoride found in toothpaste and that present in saliva, during and after brushing, was evaluated as an indicator of potentially bioavailable fluoride in toothpaste. Ten adult participants brushed their teeth with the assigned toothpastes: group I: fresh sample of a fluoride toothpaste: Na2FPO3/CaCO3, 1,378 µg F/g of total soluble fluoride (TSF); groups II-IV: aged samples of toothpaste presenting TSF concentrations of 1,160, 900, and 597 µg F/g, respectively; group V: non-F placebo toothpaste. The volunteers brushed their teeth for 1 min with 0.7 g of the toothpaste, all toothbrushing residues (TR) produced were collected, the mouth was rinsed with water, and saliva samples were collected up to 120 min. Total fluoride (TF) and TSF concentrations were determined in TR and in saliva samples using a fluoride ion-selective electrode. TSF concentration (µg F/mL) in TR was determined as an indicator of fluoride bioavailability during toothbrushing and the areas under curves of saliva fluoride concentration versus time (area under the curve, AUC = µg F/mL × min) were calculated as an indicator of fluoride bioavailability after toothbrushing. A significant correlation was found between the TSF concentrations in the toothpastes and the variables TR (r = 0.850; p = 0.0001) and AUC (r = 0.445; p = 0.004). For TF no significant correlation was found for TR (r = -0.099; p = 0.542) and AUC (r = -0.018; p = 0.912). The findings suggest that TSF concentration chemically found in Na2FPO3/CaCO3-based toothpaste could estimate how much fluoride would be bioavailable in saliva when the teeth are brushed.

Proteolytic activity, degradation, and dissolution of primary and permanent teeth.

BACKGROUND: Primary and permanent teeth composition may influence dissolution and degradation rates. AIM: To compare the dissolution and degradation of primary and permanent teeth. DESIGN: Enamel and dentin powders were obtained from primary molars and premolars and incubated within different pH buffers. Calcium and inorganic phosphate release was quantified in the buffers by atomic absorption and light spectrophotometry. A colorimetric assay was used to assess the MMP activity of primary dentin (PrD) and permanent dentin (PeD). Collagen degradation was assessed by dry mass loss, change in elastic modulus (E), and ICTP and CTX release. Data were submitted to ANOVA and Tukey's tests (α = 0.05). RESULTS: Similar dissolution was found between PrD and PeD after 256 hours. At pH 4.5, enamel released more minerals than dentin whereas at pH 5.5 the inverse result was observed. MMP activity was similar for both substrates. PrD showed higher dry mass loss after 1 week. In general, greater reduction in E was recorded for PrD. Higher quantities of ICTP and CTX were released from PrD after 1 week. CONCLUSIONS: Primary and permanent teeth presented similar demineralization rates. Collagen degradation, however, was faster and more substantial for PrD.

Fluoride Dentifrice Overcomes the Lower Resistance of Fluorotic Enamel to Demineralization.

We evaluated if the low resistance of fluorotic enamel to demineralization could be overcome by fluoride dentifrice (FD) treatment. Paired enamel slabs of sound and fluorotic enamel (n = 20/group) from human teeth presenting Thylstrup and Fejerskov index (TF) scores from 0 to 4 were obtained. Half of the anatomic surface of the enamel slabs was isolated and used as a control (baseline) regarding enamel mineralization and fluoride concentration. The slabs were submitted to a pH-cycling model simulating a high cariogenic challenge, and 2×/day they were treated with placebo dentifrice (PD) or FD (1,100 µg F/g, as NaF). After 10 days, the slabs were cut into two halves. Enamel demineralization was evaluated by cross-sectional microhardness in one half, and the fluoride formed (FF) concentration was determined in the other half. For statistical analysis, the data on net demineralization area (ΔΔS) and FF (µg F/g) were grouped into TF0, TF1-2, and TF3-4, and analyzed by two-way ANOVA followed by Tukey's test (α = 5%). The factors studied were TF (0, 1-2, and 3-4) and dentifrice treatment (PD or FD). The effect of the factors was statistically significant for ΔΔS and FF (p < 0.05). In the PD group, the following pattern for ΔΔS was observed: TF3-4 > TF1-2 > TF0 (p < 0.05); however, the groups did not differ (p > 0.05) when FD was used. Regarding FF, the groups treated with PD did not differ (p > 0.05), but the greatest (p < 0.05) FF concentration was found in group TF3-4 treated with FD. These findings suggest that the higher susceptibility of fluorotic enamel to demineralization lesions is decreased by the use of FD.

Fluoride Binding to Dental Biofilm Bacteria: Synergistic Effect with Calcium Questioned.

It has been suggested that fluoride binding to dental biofilm is enhanced when more bacterial calcium binding sites are available. However, this was only observed at high calcium and fluoride concentrations (i.e., when CaF2 precipitation may have occurred). We assessed fluoride binding to Streptococcus mutans pellets treated with calcium and fluoride at concentrations allowing CaF2 precipitation or not. Increasing calcium concentration resulted in a linear increase (p < 0.01) in fluoride concentration only in the pellets in which CaF2 precipitated. The results suggest that CaF2 precipitation, rather than bacterially bound fluoride, is responsible for the increase in fluoride binding to dental biofilm with the increase in calcium availability.

Fluoride Penetration and Clearance Are Higher in Exopolysaccharide-Containing Bacterial Pellets.

Extracellular polysaccharides (EPS) could increase the penetration of fluoride through dental biofilm, reducing its cariogenicity. We measured the concentration of fluoride in EPS-containing (EPS+) or not-containing (EPS-) Streptococcus mutans bacterial pellets resembling test biofilms, before and up to 60 min after a 0.05% NaF rinse in situ. Fluoride penetration and clearance were higher in EPS+ bacterial pellets. The data suggest that EPS enhances fluoride penetration, but also accelerates fluoride clearance from dental biofilms.

Starch Combined with Sucrose Provokes Greater Root Dentine Demineralization than Sucrose Alone.

Since there is no consensus about whether starch increases the cariogenic potential of sucrose, we used a validated 3-species biofilm model to evaluate if starch combined with sucrose provokes higher root dentine demineralization than sucrose alone. Biofilms (n = 18) composed by Streptococcus mutans (the most cariogenic bacteria), Actinomces naeslundii (which has amylolytic activity), and Streptococcus gordonii (which binds salivary amylase) were formed on root dentine slabs under exposure 8 ×/day to one of the following treatments: 0.9% NaCl, 1% starch, 10% sucrose, or a combination of 1% starch and 10% sucrose. Before each treatment, biofilms were pretreated with human whole saliva for 1 min. The pH of the culture medium was measured daily as an indicator of biofilm acidogenicity. After 96 h of growth, the biofilms were collected, and the biomass, bacteria viability, and polysaccharides were analyzed. Dentine demineralization was assessed by surface hardness loss (% SHL). Biofilm bioarchitecture was analyzed using confocal laser scanning microscopy. Treatment with a starch and sucrose combination provoked higher (p = 0.01) dentine demineralization than sucrose alone (% SHL = 53.2 ± 7.0 vs. 43.2 ± 8.7). This was supported by lower pH values (p = 0.007) of the culture medium after daily exposure to the starch and sucrose combination compared with sucrose (4.89 ± 0.29 vs. 5.19 ± 0.32). Microbiological and biochemical findings did not differ between biofilms treated with the combination of starch and sucrose and sucrose alone (p > 0.05). Our findings give support to the hypothesis that a starch and sucrose combination is more cariogenic for root dentine than sucrose alone.

Effect of 5,000 ppm Fluoride Dentifrice or 1,100 ppm Fluoride Dentifrice Combined with Acidulated Phosphate Fluoride on Caries Lesion Inhibition and Repair.

High fluoride dentifrice (FD; 5,000 ppm F) has been recommended to arrest root dentine lesions and to control enamel caries in high-risk patients. Also, standard FD (1,100 ppm F) in combination with professional fluoride application has been recommended to control dentine caries, but the effect of this combination on enamel has been considered modest. Considering the lack of evaluation comparing the use of 5,000 ppm FD (5,000-FD) versus acidulated phosphate fluoride (APF) application combined with 1,100 ppm FD (1,100-FD) on the inhibition and repair of caries lesions in both enamel and dentine, we conducted this in situ, double-blind, crossover study of 3 phases of 14 days. In each phase, 18 volunteers wore palatal appliances containing enamel and root dentine specimens, either sound or carious, to evaluate the effect of the treatments on the inhibition or repair of caries lesions, respectively. The treatments were non-FD (negative control), 5,000-FD, or 1 APF gel application on dental specimens combined with 1,100-FD used twice per day (APF + 1,100-FD). The reduction of demineralization and enhancement of remineralization were assessed by surface and cross-sectional hardness. Fluoride concentration was determined on dental specimens and on the formed biofilm. For enamel, APF + 1,100-FD and 5,000-FD did not differ regarding the inhibition of demineralization and repair of caries lesions. However, for dentine the difference between these treatments was inconclusive because while APF + 1,100-FD was more effective than 5,000-FD in caries lesion reduction and repair, 5,000-FD was more effective than APF + 1,100-FD in the reduction of surface demineralization. Therefore, the findings show that the combination of APF + 1,100-FD is as effective as 5,000-FD in enamel inhibition of demineralization and enhancement of remineralization.

Frequency of Fluoride Dentifrice Use and Caries Lesions Inhibition and Repair.

The clinical relevance of the frequency of fluoride dentifrice (FD) use on enamel caries is based on evidence. However, the relative effect of FD on reduction of demineralization or enhancement of remineralization is unknown and the effect of frequency on root dentine caries has not been explored. The aim of this double-blind, crossover, in situ study, which was conducted in 4 phases of 14 days each, was to evaluate the relationship between the frequency of FD use and enamel and root dentine de- and remineralization. Eighteen volunteers wore palatal appliances containing enamel and root dentine slabs, either sound or carious. Biofilm accumulation on the slab surface was allowed, and 20% sucrose solution was dripped 3 or 8 times per day on the carious and sound slabs, respectively. Volunteers used FD (1,100 µg F/g) in the frequencies 0 (fluoride-placebo dentifrice), 1, 2 and 3 times per day. The demineralization and remineralization that occurred in sound or carious slabs was estimated by the percentage of surface hardness loss (%SHL) or recovery (%SHR). Loosely (CaF2) and firmly (FAp) bound fluoride concentrations were also determined. The relationship between the variables was analyzed by linear regression. The %SHL, CaF2 and FAp concentrations were a function of the frequency of FD use for enamel and dentine, but the %SHR was a function of the frequency of FD use only for enamel (p < 0.05). The results suggest that demineralization in enamel and root dentine is reduced in proportion to the frequency of FD use, but for remineralization the effect of the frequency of FD use was relevant only to enamel.

Higher Fluorosis Severity Makes Enamel Less Resistant to Demineralization.

Fluorotic teeth could either be more resistant or more susceptible to the caries process than sound ones due to their higher enamel fluoride concentration and higher porosity (subsurface hypomineralization), respectively; however, there is no consensus on this subject. In this study, a total of 49 human unerupted third molars presenting Thylstrup and Fejerskov (TF) fluorosis scores 0-4 were used. Two enamel slabs were obtained from each tooth. The rest of the tooth crown was powdered, and the enamel was separated from the dentine. In purified powdered enamel, the calcium (Ca), inorganic phosphate (Pi), and fluoride (F) concentrations were determined. The F concentration gradient throughout the enamel and in the enamel volume was determined in one slab. The other enamel slab was isolated with acid-resistant varnish, subjecting the exposed enamel surface half to a pH-cycling model to evaluate its demineralization resistance and to calculate the demineralization area. The nonexposed surface was used to determine the natural hypomineralization area found in fluorotic enamel and normalize the demineralization data. The hypomineralization and demineralization areas were assessed by cross-sectional microhardness. For statistical analyses, the data for TF1 and 2, and for TF3 and 4 were pooled. Concentrations of powered enamel Ca and Pi were not significantly different (p > 0.05) among groups TF0, TF1-2 and TF3-4, but a higher F concentration was found in fluorotic enamel (p < 0.05). Highly fluorotic teeth (TF3-4) presented a greater hypomineralization subsurface area and demonstrated lower demineralization resistance than sound enamel (p < 0.05). The findings suggest that a higher severity of fluorosis makes enamel less resistant to the caries process due to its greater subsurface mineral area exposed to demineralization and deeper acid diffusion through the enamel.

Breastfeeding, Dental Biofilm Acidogenicity, and Early Childhood Caries.

AIM: This study evaluated the acidogenicity of human milk by the dental biofilms of children with and without early childhood caries (ECC). METHOD: Biofilms of 16 children (7 with ECC; 9 caries free) were exposed to human milk or 10% sucrose solution in the crossover design, and the biofilm pH was determined. RESULTS: Breastfeeding did not provoke a decrease in biofilm pH, irrespective of the children's caries status, whereas sucrose decreased the pH for both groups. In addition, higher x0394;pH5min (pH variation occurring at 5 min) was observed in the biofilms of ECC children (p < 0.05). The results suggest that breastfeeding may not contribute to ECC.

Evaluation of low fluoride toothpaste using primary enamel and a validated pH-cycling model.

AIM: To develop and validate pH-cycling model for primary enamel, which was then used to evaluate the anti-caries potential of fluoride toothpastes. DESIGN: Human primary enamel slabs were subjected to pH-cycling model for 10 days and maintained for 6 h in demineralizing solution and 18 h in remineralizing solution daily. Twice/day, the slabs were treated. To validate it, the treatments were water or solutions containing 62.5, 125, 250, and 375 µg F/mL. Commercial toothpastes containing no fluoride, 500, 1100, and 1450 µg F/g were evaluated. Demineralization was assessed by percentage of surface hardness loss (%SHL) and cross-sectional hardness (ΔS). Fluoride dose-response effect was analysed by quadratic regression and the effects of toothpastes by Tukey's test. RESULTS: Dose-response effect was found between fluoride concentration and %SHL (R2  = 0.7047; P < 0.01) or ΔS (R2  = 0.4465; P < 0.01). %SHL and ΔS (mean ± SD) for the group treated with 500 µg F/g toothpaste was 36.6 ± 8.0 and 6298.5 ± 1221.3, respectively, which were significantly higher than those treated with 1100 (25.2 ± 8.7; 4565.7 ± 1122) and 1450 µg F/g (24.2 ± 5.2; 2339.1 ± 879.7) toothpastes. CONCLUSION: The developed pH-cycling model may be used to evaluate and compare the anti-caries potential of toothpaste formulations with low fluoride concentration because it presents dose-response effects on the reduction of primary enamel demineralization.

A three-species biofilm model for the evaluation of enamel and dentin demineralization.

Although Streptococcus mutans biofilms have been useful for evaluating the cariogenic potential of dietary carbohydrates and the effects of fluoride on dental demineralization, a more appropriate biofilm should be developed to demonstrate the influence of other oral bacteria on cariogenic biofilms. This study describes the development and validation of a three-species biofilm model comprising Streptococcus mutans, Actinomyces naeslundii, and Streptococcus gordonii for the evaluation of enamel and dentin demineralization after cariogenic challenges and fluoride exposure. Single- or three-species biofilms were developed on dental substrata for 96 h, and biofilms were exposed to feast and famine episodes. The three-species biofilm model produced a large biomass, mostly comprising S. mutans (41%) and S. gordonii (44%), and produced significant demineralization in the dental substrata, although enamel demineralization was decreased by fluoride treatment. The findings indicate that the three-species biofilm model may be useful for evaluating the cariogenic potential of dietary carbohydrates other than sucrose and determining the effects of fluoride on dental substrata.

Influence of daily immersion in denture cleanser on multispecies biofilm.

OBJECTIVE: The aim of this study was to evaluate the effect of daily exposure to a denture cleanser on a multispecies biofilm. MATERIALS AND METHODS: Multispecies biofilms (five bacteria and Candida albicans) were developed for 64.5 h on acrylic resin specimens and randomized into control and experimental groups. In the experimental group, biofilms were immersed in denture cleanser for 3 min/day for seven consecutive days. In the control group, the biofilms were developed with no treatment for the same period. Biofilms from both groups were collected after 1, 4, and 7 days and analyzed for the number of microorganisms and polysaccharide concentrations. Scanning electron microscopy (SEM) and confocal microscopy (CLSM) analyses were performed. RESULTS: The total microorganism counts and bacterial populations were lower in the experimental group compared to the control group for all of the periods evaluated. However, the C. albicans counts continuously increased in all of the cleanser-exposed biofilms, with abundant hyphae forms on SEM and CLSM images. The polysaccharide concentration was significantly higher in the experimental group after 7 days. CONCLUSIONS: Daily exposure of a multispecies biofilm to a denture cleanser reduces the number of total microorganisms but favors C. albicans development. CLINICAL RELEVANCE: Daily use of denture cleanser is an effective method for controlling bacteria in biofilm, but it can potentially select C. albicans, an important etiological agent of oral candidosis.

Brazilian primary dental care in a universal health system: Challenges for training and practice.

OBJECTIVES: To report the challenges for training and practice for the Brazilian primary dental care in a universal health system. METHODS: Health, education and protection rights against poverty are guaranteed by the 1988 Brazilian Constitution and public health in Brazil is provided by the Unified Health System (SUS), one of the largest public health systems in the world. According to SUS, every Brazilian citizen has the right to free primary oral health care as secondary and tertiary care, offering a unique opportunity to integrate oral care within general health care. RESULTS: The Brazilian undergraduate Dental curriculum was updated in 2021 aiming to graduate general practitioners with a major in comprehensive health care in primary health care, integrated with public and general health. This curriculum update requires at least 20% of the academic hours to be exercised outside the university walls (extramural or community work), preferably within the SUS. CONCLUSIONS: Considering the World Health Organization (WHO) agenda, Brazil needs to advance the innovative oral health workforce, the integration of oral health into primary care, the population access to essential dental medicines and optimal fluorides for caries control. CLINICAL SIGNIFICANCE: It is necessary political action and the engagement of multiple stakeholders, mainly from the health and education sectors, to improve primary health care.