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.

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.

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.

Dispensing Device to Deliver Small and Standardized Amount of Fluoride Dentifrice on the Toothbrush

Abstract Objective: To evaluate the efficacy of a dispensing device specially developed to standardize the amount of fluoride dentifrice to be delivered on the toothbrush. The amount and variability of dentifrice applied using this device were compared with recommendations to apply dentifrice amounts equivalent to "rice size" or "pea-size". Material and Methods: Two dentifrices, one used by children (NaF/Silica-based) and one used by the entire family (MFP/CaCO3-based), and five methods to apply them on the toothbrush (pea and rice sizes, and three different amounts using the developed device) were tested by 12 volunteers. The amount of dentifrice placed on the toothbrush was weighed, and the experiment was repeated three times. Data were analyzed by two-way ANOVA and Tukey test. Results: No differences were observed between the dentifrices used (p>0.05), but the method of application significantly affected the amount of dentifrice applied (p<0.05). Smaller amounts (p<0.05) and less variability were observed when the volunteers used the dispenser device than when they were asked to apply a pea or rice size. Conclusion: The device can help parents and caregivers to safely use fluoride dentifrice on children.

Impact of sense of coherence on oral health-related quality of life among Brazilian adults.

It has been postulated that oral health-related quality of life (OHRQoL) may be affected by the sense of coherence (SOC), but there are no epidemiological studies investigating this association in Brazilian adults. The present study was conducted among adults of a mid-sized Brazilian city, with the aim of looking into this association. The probability sampling consisted of 342 adults aged 35-44 years old, from a mid-sized Brazilian city, who were examined at their homes for caries (Decayed, Missing and Filled Teeth [DMFT] Index) and periodontal disease (Community Periodontal Index - CPI), according to WHO criteria. The questionnaire applied included demographic factors, socioeconomic information, use of dental services, behavior, SOC and the Oral Health Impact Profile (OHIP). The OHIP outcome, measured by prevalence of the impact, was analyzed by binary logistic regression using a hierarchical approach, a conceptual model, and a 5% significance level. A total of 67.9% of the respondents had one or more impacts on OHRQoL, and 54.4% showed a high SOC. The impact on OHRQoL was more prevalent in adults who had a manual occupation (PR = 2.47, 95%CI 1.24-4.93), those who perceived the need for dental treatment (PR = 2.93, 95%CI 1.67-5.14), and those who had untreated caries (PR = 1.93, 95%CI 1.07-3.47). Those with a low SOC had a twofold higher prevalence of impact on OHRQoL (PR = 2.19, 95%CI 1.29-3.71). This impact on OHRQoL was associated with a low SOC, even after adjusted by socioeconomic, behavioral and clinical factors. Future studies should consider the SOC in determining the oral health impact on quality of life.

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.

Impact of sense of coherence on oral health-related quality of life among Brazilian adults

Abstract It has been postulated that oral health-related quality of life (OHRQoL) may be affected by the sense of coherence (SOC), but there are no epidemiological studies investigating this association in Brazilian adults. The present study was conducted among adults of a mid-sized Brazilian city, with the aim of looking into this association. The probability sampling consisted of 342 adults aged 35-44 years old, from a mid-sized Brazilian city, who were examined at their homes for caries (Decayed, Missing and Filled Teeth [DMFT] Index) and periodontal disease (Community Periodontal Index - CPI), according to WHO criteria. The questionnaire applied included demographic factors, socioeconomic information, use of dental services, behavior, SOC and the Oral Health Impact Profile (OHIP). The OHIP outcome, measured by prevalence of the impact, was analyzed by binary logistic regression using a hierarchical approach, a conceptual model, and a 5% significance level. A total of 67.9% of the respondents had one or more impacts on OHRQoL, and 54.4% showed a high SOC. The impact on OHRQoL was more prevalent in adults who had a manual occupation (PR = 2.47, 95%CI 1.24-4.93), those who perceived the need for dental treatment (PR = 2.93, 95%CI 1.67-5.14), and those who had untreated caries (PR = 1.93, 95%CI 1.07-3.47). Those with a low SOC had a twofold higher prevalence of impact on OHRQoL (PR = 2.19, 95%CI 1.29-3.71). This impact on OHRQoL was associated with a low SOC, even after adjusted by socioeconomic, behavioral and clinical factors. Future studies should consider the SOC in determining the oral health impact on quality of life.

Kinetics of calcium binding to dental biofilm bacteria.

Dental biofilm bacteria can bind calcium ions and release them during a pH drop, which could decrease the driving force for dental demineralization (i.e. hydroxyapatite dissolution) occurring at reduced pHs. However, the kinetics of this binding and release is not completely understood. Here we validated a method to evaluate the kinetics of calcium binding and release to/from Streptococcus mutans, and estimated the importance of this reservoir as a source of ions. The kinetics of calcium binding was assessed by measuring the amount of bound calcium in S. mutans Ingbrit 1600 pellets treated with PIPES buffer, pH 7.0, containing 1 or 10 mM Ca; for the release kinetics, bacterial pellets previously treated with 1 mM or 10 mM Ca were exposed to the calcium-free or 1 mM Ca PIPES buffer, pH 7.0, for up to 60 min. Binding and release curves were constructed and parameters of kinetics were calculated. Also, calcium release was assessed by exposing pellets previously treated with calcium to a pH 5.0 buffer for 10 min. Calcium binding to bacteria was concentration-dependent and rapid, with maximum binding reached at 5 min. On the other hand, calcium release was slower, and according to the calculations, would never be complete in the groups pretreated with 10 mM Ca. Decreasing pH from 7.0 to 5.0 caused a release of calcium able to increase the surrounding fluid calcium concentration in 2 mM. The results suggest that dental biofilm bacteria may act as a calcium reservoir, rapidly binding ions from surrounding fluids, releasing them slowly at neutral pH and promptly during a pH drop.

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.

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.

Calcium Prerinse before Fluoride Rinse Reduces Enamel Demineralization: An in situ Caries Study.

A calcium (Ca) prerinse before a fluoride (F) rinse has been shown to increase oral F levels. We tested the anticaries effect of this combination in a dose-response in situ caries model. In a double-blind, crossover experiment, 10 volunteers carried enamel slabs in palatal appliances for 14 days, during which they rinsed twice/day with one of four rinse combinations: (1) a placebo prerinse (150 mM sodium lactate) followed by a distilled water rinse (negative control); (2) a placebo prerinse followed by a 250 ppm F rinse; (3) a placebo prerinse followed by a 1,000 ppm F rinse, or (4) a Ca prerinse (150 mM Ca, as calcium lactate) followed by a 250 ppm F rinse. Sucrose solution was dripped onto the slabs 8×/day to simulate a high cariogenic challenge. The percent surface hardness loss (%SHL) was significantly lower in the Ca prerinse used with the 250 ppm F rinse group (%SHL = 38.0 ± 21.0) when compared with the F rinse alone (%SHL = 59.5 ± 24.1) and similar to the 1,000 ppm F rinse group (%SHL = 42.0 ± 18.3). Compared with the 250 ppm F rinse, the Ca prerinse increased biofilm fluid F only twice (nonsignificant). However, it greatly increased F in biofilm solids (∼22×). The Ca prerinse had little effect on loosely or firmly bound enamel F. The results showed an increased level of protection against demineralization by the use of a Ca prerinse, which seems to be caused by the enhancement of F concentration in the biofilm.

Anticaries Potential of Low Fluoride Dentifrices Found in The Brazilian Market

Abstract Low-fluoride (F) dentifrices (<600 µg F/g) are widely available worldwide, but evidence to recommend the use of such dentifrices, with either regular or improved formulations, is still lacking. Therefore, the aim of this study was to evaluate the anticaries potential of low-F dentifrices found in the Brazilian market, using a validated and tested pH-cycling model. Enamel blocks were selected by surface hardness (SH) and randomized into four treatment groups (n=12): non-F dentifrice (negative control), low-F dentifrice (500 μg F/g), low-F acidulated dentifrice (550 μg F/g) and 1,100 μg F/g dentifrice (positive control). The blocks were subjected to pH-cycling regimen for 8 days and were treated 2x/day with dentifrice slurries prepared in water (1:3, w/v). The pH of the slurries was checked, and only the acidulated one had low pH. After the pH cycling, SH was again determined and the percentage of surface hardness loss was calculated as indicator of demineralization. Loosely- and firmly-bound F concentrations in enamel were also determined. The 1,100 μg F/g dentifrice was more effective than the low-F ones to reduce enamel demineralization and was the only one that differed from the non-F (p<0.05). All F dentifrices formed higher concentration of loosely-bound F on enamel than the non-F (p<0.05), but the 1,100 μg F/g was the only one that differed from the non-F in the ability to form firmly-bound F. The findings suggest that the low-F dentifrices available in the Brazilian market, irrespective of their formulation, do not have anticaries potential.

Resumo Dentifrícios de baixa concentração de fluoreto (F) (< 600 µg F/g) estão amplamente disponíveis no mundo, mas ainda não há evidência para recomendar seu uso, quer seja em formulações regulares ou melhoradas. Assim, o objetivo deste estudo foi avaliar o potencial anticárie de dentifrícios de baixa concentração de fluoreto encontrados no mercado brasileiro, utilizando um modelo de ciclagens de pH validado e testado. Blocos de esmalte bovinos foram selecionados pela dureza de superfície e randomizados em quatro grupos (n=12): dentifrício sem fluoreto (controle negativo), dentifrício de baixa concentração de fluoreto (500 μg F/g), dentifrício acidulado de baixa concentração de fluoreto (550 μg F/g) e dentifrício de 1100 μg F/g (controle positivo). Os blocos foram submetidos ao regime de ciclagem de pH por 8 dias e tratados 2 x/dia com suspensões aquosas dos dentifrícios (1:3 p/v). O pH das suspensões foi checado, e apenas o acidulado tinha baixo pH. Após a ciclagem de pH, a dureza de superfície foi novamente determinada e a porcentagem de perda de dureza foi calculada como indicador de demineralização. As concentrações de fluoreto fracamente e firmemente ligado ao esmalte também foram determinadas. O dentifrício de 1.100 μg F/g foi mais efetivo do que os de baixa concentração na redução da desmineralização do esmalte e foi o único que diferiu significativamente do não fluoretado (p<0,05). Todos os dentifrícios fluoretados foram capazes de formar maiores concentrações de fluoreto fracamente ligado ao esmalte do que o não fluoretado (p<0,05), mas o de 1.100 μg F/g foi o único que diferiu do não fluoretado na capacidade de formar fluoreto firmemente ligado ao esmalte. Os resultados sugerem que dentifrícios de baixa concentração de fluoreto disponíveis no mercado brasileiro, independentemente da formulação, não têm potencial anticárie.

Anticaries Potential of Low Fluoride Dentifrices Found in The Brazilian Market.

Low-fluoride (F) dentifrices (<600 µg F/g) are widely available worldwide, but evidence to recommend the use of such dentifrices, with either regular or improved formulations, is still lacking. Therefore, the aim of this study was to evaluate the anticaries potential of low-F dentifrices found in the Brazilian market, using a validated and tested pH-cycling model. Enamel blocks were selected by surface hardness (SH) and randomized into four treatment groups (n=12): non-F dentifrice (negative control), low-F dentifrice (500 µg F/g), low-F acidulated dentifrice (550 µg F/g) and 1,100 µg F/g dentifrice (positive control). The blocks were subjected to pH-cycling regimen for 8 days and were treated 2x/day with dentifrice slurries prepared in water (1:3, w/v). The pH of the slurries was checked, and only the acidulated one had low pH. After the pH cycling, SH was again determined and the percentage of surface hardness loss was calculated as indicator of demineralization. Loosely- and firmly-bound F concentrations in enamel were also determined. The 1,100 µg F/g dentifrice was more effective than the low-F ones to reduce enamel demineralization and was the only one that differed from the non-F (p<0.05). All F dentifrices formed higher concentration of loosely-bound F on enamel than the non-F (p<0.05), but the 1,100 µg F/g was the only one that differed from the non-F in the ability to form firmly-bound F. The findings suggest that the low-F dentifrices available in the Brazilian market, irrespective of their formulation, do not have anticaries potential.

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.

Fluoride rinse effect on retention of CaF2 formed on enamel/dentine by fluoride application.

Calcium fluoride-like materials ("CaF2") formed on dental surfaces after professional fluoride application are unstable in the oral environment but can be retained longer with a daily NaF mouthrinse. We tested the effect of twice daily 0.05% NaF rinses on the retention of "CaF2" formed on enamel and dentine after applying acidulated phosphate fluoride (APF). "CaF2" formed on enamel/dentine by APF application significantly decreased after exposure to artificial saliva and the 0.05% NaF rinse was ineffective to avoid this reduction. These findings suggest that the combination of APF and 0.05% NaF is not clinically relevant, either for caries or dental hypersensitivity.

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.

Práticas preventivas realizadas por Técnicos em Saúde Bucal: um estudo qualitativo / Preventive practices carried out by technicians in oral health: a qualitative study

A cárie dentária é uma doença comum que pode ser totalmente controlada. Entretanto, a percepção de técnicos em saúde bucal (TSBs) quanto sua prevenção ainda é pouco explorada. O objetivo desse estudo foi identificar a percepção dos TSBs com relação aos fatores facilitadores para adoção de práticas de prevenção no controle da cárie dentária. Participaram desta pesquisa 10 TSBs pertencentes à 15ª Regional de Saúde do Paraná. As entrevistas semiestruturadas foram realizadas face a face e gravadas. A transcrição das gravações foi realizada de forma manual e avaliada segundo a análise de conteúdo proposta por Bardin, utilizando-se o software Visual Qualitative Data Analysis 7.0. Os resultados apontaram 12 fatores facilitadores para a prevenção da cárie, dentre eles: capacitação profissional; consciência, satisfação e motivação em realizar procedimentos preventivos e trabalho em equipe. Além disso, a habilidade de trabalhar com educação em saúde e com educação permanente foram fatores relevantes destacados nas entrevistas. De modo geral, os fatores facilitadores quanto a adoção de práticas de prevenção no controle da cárie dentária, identificados na percepção dos TSBs foram a consciência de realizar a prevenção na sua prática diária; a habilidade de comunicação para realizar educação em saúde e a satisfação do profissional em trabalhar com prevenção. Todos esses fatores relatados parecem ser necessários para o desempenho adequado da função dos TSBs, superando o modelo biologicista e avançando no entendimento do processo saúde-doença, a fim de implementar estratégias para o controle da cárie dentária na população (AU).

Dental caries is a common disease that can be fully controlled. However, the perception of oral health technicians (OHTs) and its prevention is still little explored. The aim of this study was to identify the perception of OHTs with regard to factors that facilitate the adoption of practices in preventing the control of dental caries, participated in this study 10 OHTs belonging to the 15th Regional of Health of Paraná. The semi-structured interviews were conducted face to face and recorded. The transcript of the recordings was done manually and evaluated according to the content analysis proposed by Bardin, using the Visual Qualitative Data Analysis 7.0 software. The results showed 12 facilitating factors for caries prevention, including: professional training; awareness, satisfaction and motivation in performing preventive procedures and teamwork. In addition, the ability to work with health education and continuing education were relevant factors highlighted in the interviews. In general, the risk factors as the adoption of preventive practices in controlling dental caries, identified in the perception of OHTs were the consciousness of performing prevention in their daily practice; the communication skills to carry out health education and professional satisfaction in working with prevention. All of these reported factors appear to be necessary for the proper performance of the function of OHTs, surpassing biologicist model and advancing the understanding of the healthdisease, in order to implement strategies for the control of dental caries in the population (AU).

Necessity to review the Brazilian regulation about fluoride toothpastes.

The aim of this study was to evaluate the adequacy of the Brazilian legislation about fluoride toothpaste. A search was conducted in LILACS, Medline and SciELO databases about the fluoride concentration found in Brazilians toothpastes, using descriptors on health. Publications since 1981 have shown that some Brazilian toothpastes are not able to maintain, during their expiration time, a minimum of 1,000 ppm F of soluble fluoride in the formulation. However, the Brazilian regulation (ANVISA, Resolution 79, August 28, 2000) only sets the maximum total fluoride (0.15%; 1,500 ppm F) that a toothpaste may contain but not the minimum concentration of soluble fluoride that it should contain to have anticaries potential, which according to systematic reviews should be 1,000 ppm F. Therefore, the Brazilian regulation on fluoride toothpastes needs to be revised to assure the efficacy of those products for caries control.

Concentração de fluoreto nos dentifrícios a base de MFP/CaCO3 mais vendidos no Brasil, ao final dos seus prazos de validade / Fluoride concentration in most sold MFP/CaCO3 -based Brazilian toothpastes at the expiration time

Dentifrício fluoretado deve conter pelo menos 1.000 ppm (mg F/kg) do seu flúor total (FT) na forma quimicamente solúvel (FST) para ter o potencial máximo de interferir com o processo de cárie. Em formulações de dentifrícios contendo cálcio no abrasivo, a concentração de FST (íon flúor + íon MFP) diminui em função do tempo de armazenamento. Os quatro dentifrícios a base de MFP/CaCO3 mais vendidos no Brasil são capazes de manter 1.000 ppm de FST nos produtos pelo prazo de um ano de fabricação, mas não é conhecido o que ocorre até o final do prazo de validade. Assim, o objetivo deste estudo foi avaliar a concentração de FST nesses dentifrícios ao final do seu prazo de validade. Após as análises iniciais realizadas em 2010, os cremes dentais (n=30) foram armazenados à temperatura laboratorial (25°C) e as concentrações de FT e FST foram novamente determinadas em 2012, próximo a data de vencimento (36 meses). As análises foram feitas utilizando protocolo validado de extração, as determinações foram feitas com eletrodo íon específico e os resultados expressos em ppm F (mg F/kg). A concentração (média±dp;n=30) de FT encontrada (1.415,2±62,8) estava de acordo com o declarado pelo fabricante (1.450 ppm F), porém a de FST foi 44% menor (814,7±74,7). Ao final do prazo de validade, os dentifrícios brasileiros mais vendidos não mantêm uma concentração de FST máxima desejável, mostrando tanto a importância do Cirurgião-Dentista na orientação do paciente como a necessidade da revisão da resolução Anvisa nº 79 que regulamenta a matéria sobre dentifrícios

Fluoride toothpaste should contain at least 1,000 ppm (mg F/kg) of fluoride chemically soluble to have the maximum potential to interfere with the caries process. In formulations containing calcium--based abrasives, the concentration of total soluble fluoride (TSF = fluoride ion + MFP ion) decreases according to the storage time. The four MFP/CaCO3-based toothpastes most consumed in Brazil are able to maintain 1,000 ppm of TSF throughout one year of manufacturing, but it is not known if it would be maintained up to the expiration date. Thus, this study evaluated the concentration of TSF in these toothpastes at the end of expiration date. As control, the total fluoride (TF) concentration was also determined. After the analysis of fresh samples conducted in 2010, the toothpastes tube (n=30) were stored at temperature of 25°C and the determinations of TF and TSF concentrations were again assessed in 2012, close to the expiration date of the toothpastes (3 years). The analyses were made using a validated protocol of extraction, the determinations were made with an ion specific electrode and the results were expressed in ppm F (mg F/kg). The concentration (mean±SD;n=30) of TF found (1.415.2±62.8) was according to the declared by the manufacturer (1.450 ppm), but the TSF was 44% lower (814.7±74.7). At expiration, the most sold MFP/CaCO3-based brazilian toothpastes do not maintain the maximum TSF concentration required, showing not only the relevance of the Dentist to advise the patients about this subject, but also the necessity to review the Brazilian regulation about toothpastes