Farnesal-loaded pH-sensitive polymeric micelles provided effective prevention and treatment on dental caries.

BACKGROUND: Farnesol is a sesquiterpene from propolis and citrus fruit that shows promising anti-bacterial activity for caries treatment and prevention, but its hydrophobicity limits the clinical application. We aimed to develop the novel polymeric micelles (PMs) containing a kind of derivative of farnesol and a ligand of pyrophosphate (PPi) that mediated PMs to adhere tightly with the tooth enamel. RESULTS: Farnesal (Far) was derived from farnesol and successfully linked to PEG via an acid-labile hydrazone bond to form PEG-hyd-Far, which was then conjugated to PPi and loaded into PMs to form the aimed novel drug delivery system, PPi-Far-PMs. The in vitro test about the binding of PPi-Far-PMs to hydroxyapatite showed that PPi-Far-PMs could bind rapidly to hydroxyapatite and quickly release Far under the acidic conditions. Results from the mechanical testing and the micro-computed tomography indicated that PPi-Far-PMs could restore the microarchitecture of teeth with caries. Moreover, PPi-Far-PMs diminished the incidence and severity of smooth and sulcal surface caries in rats that were infected with Streptococcus mutans while being fed with a high-sucrose diet. The anti-caries efficacy of free Far can be improved significantly by PPi-Far-PMs through the effective binding of it with tooth enamel via PPi. CONCLUSIONS: This novel drug-delivery system may be useful for the treatment and prevention of dental caries as well as the targeting therapy of anti-bacterial drugs in the oral disease.

Application of green tea extracts epigallocatechin-3-gallate in dental materials: Recent progress and perspectives.

Because of excellent biocompatibility, antioxidant activity, and anti-caries ability, epigallocatechin-3-gallate (EGCG) has been widely studied in the treatment of oral diseases, such as periodontal disease, oral cancer, and dental caries. To reach the site of the lesion or achieve sustained release, play the role of anti-caries, anti-inflammatory, or to maintain or improve the physical properties of the modified material，EGCG need to be cross-linked or embedded with dental adhesives, barrier membranes, bone replacement materials, tissue regeneration materials, and antimicrobial anti-caries materials to better prevent or treat oral diseases. This article reviews the applications of EGCG in oral materials, involving various areas of the oral cavity, reveals their excellent potential, and sees shortcomings in these research to promote the better development of EGCG applications in oral materials such as oral repair materials, bone tissue engineering materials and antibacterial and anti-caries materials.

In situ effect of fluoride toothpaste supplemented with nano-sized sodium trimetaphosphate on enamel demineralization prevention and biofilm composition.

OBJECTIVE: To evaluate the effect of a fluoride toothpaste containing nano-sized sodium trimetaphosphate (TMPnano) on enamel demineralization in situ and composition of the biofilm. DESIGN: This crossover double-blind study consisted of four phases (seven days each) and 12 volunteers who wore oral appliances containing four enamel bovine blocks. The cariogenic challenge was performed by 30% sucrose solution (6x/day). The toothpaste treatments (3x/day) were as follows: no F/TMP/TMPnano (Placebo), 1100 ppm F (1100F), 1100F plus 3% micrometric or nano-sized TMP (1100F/TMP; 1100F/TMPnano). Percentage of surface hardness loss (%SH), and integrated loss of subsurface hardness (ΔKHN), as well as enamel calcium (Ca), phosphorus (P), and fluoride (F) were determined. Moreover, biofilm formed on the blocks were analyzed for F, Ca, P, and insoluble extracellular polysaccharide (EPS) concentrations. Data were analyzed using one-way ANOVA, repeated measures followed by Fisher LSD test (p < 0.001). RESULTS: 1100F/TMPnano promoted the lowest %SH and ΔKHN among all groups (p < 0.001). Regarding the F concentrations in the enamel and in the biofilm, there were no significant differences between 1100 F and 1100 F/TMPnano, but significantly increased enamel Ca concentrations (p < 0.001). 1100F/TMPnano showed lower values of EPS concentration when compared with 1100F (∼80%) (p < 0.001). CONCLUSION: 1100F/TMPnano promoted a greater protective effect against enamel demineralization and significantly affected the composition of biofilm formed in situ when compared to 1100F toothpaste.

The Anticaries Efficacy of a 1.5% Arginine and Fluoride Toothpaste.

Dental caries remains a world-wide disease despite the global distribution of fluoride. It has become apparent that the introduction of significant levels of sugar (fermentable carbohydrate) into the diet has resulted in a change in the biofilm, encouraging acid formation. Further, there has been a shift in the microbiota in the biofilm to a flora that produces acid, and thrives and reproduces in an acidic environment. The management of caries activity under these conditions has focused on brushing to remove the biofilm with fluoride pastes, and high-dose fluoride treatments. Kleinberg, in the 1970s, identified an arginine-containing compound in saliva that several oral biofilm bacterial species metabolize to produce base. Multiple in situ and in vivo studies have been conducted, and have discussed the ability of multiple bacteria to increase the resting pH of the biofilm and even reduce the decrease in pH when the biofilm is challenged with glucose. This shift in resting pH can shift the level of caries formation by the biofilm. Here, we present 8 clinical studies, with different clinical designs, measuring different clinical outcomes, for a diverse, world-wide population. Each of these studies demonstrates reductions in caries formation beyond that seen with fluoride alone and several demonstrate the reversal of early caries lesions. Significant clinical research has been shown that 1.5% arginine combined with fluoride toothpaste has superior anti-caries efficacy to toothpaste containing fluoride alone.

The use of sodium trimetaphosphate for matrix metalloproteinase inhibition, remineralization and bonding to dentin / O uso de trimetafosfato de sódio sobre a inibição de metaloproteinases e na remineralização e adesão à dentina

The adhesive process to dentin substrate depends on the condition determined by the combined action of the mineral loss and the endogenous enzymes activity. Thus, considering a more complete therapeutic approach, sodium trimetaphosphate (STMP) may be a novel strategy that conciliates the remineralization potential to the promotion of dentin strengthening and its stability, possibly directing mineral nucleation and controlling the rate of biodegradation. In this study, the effect of STMP was evaluated in 2 studies. In study 1, different concentrations of STMP (0.5, 1.5, 3.5 and 5%) were investigated to assess their anti-proteolytic capacity on human purified MMPs-2 and -9 by zymography. Afterwards, only the concentrations (1.5, 3.5 and 5%) that showed total inhibition of both MMPs were used to evaluate their remineralizing capacity in dentin substrate submitted to artificial cariogenic challenge, through surface hardness (SH) and cross-sectional hardness (CSH). In study 2, based on the previous results, the capacity of the 1.5% STMP associated or not with NaF or Ca(OH)2 solutions in improving the dentin bond strength of a universal adhesive system was evaluated by the microtensile test . Thus, these studies suggest that 1.5% STMP is an effective inhibitor of collagen degradation mediated by purified human MMPs-2 and -9. In addition, demineralized and treated dentin with 1.5% STMP supplemented with Ca(OH)2 may induce remineralization. Thus, the use of STMP can be introduced as a new strategy that combines enzymatic inhibition and remineralization potential, reestablishing favorable conditions to affected dentin. These evidences support perspectives of therapies to restructure dentin and propose feasible and promising clinical strategies.(AU)

O processo adesivo ao substrato dentinário depende da condição determinada pela ação combinada da perda mineral e atividade de enzimas endógenas. Deste modo, considerando uma abordagem terapêutica mais completa, o trimetafosfato de sódio (STMP) pode ser uma estratégia inovadora que concilia o potencial remineralizador à promoção do fortalecimento da dentina e sua estabilidade, possivelmente direcionando a nucleação mineral e controlando a taxa de biodegradação. Neste trabalho, o efeito do STMP foi avaliado em 2 estudos. No estudo 1, diferentes concentrações de STMP (0,5; 1,5; 3,5 e 5%) foram investigadas para avaliar sua capacidade anti-proteolítica sobre as MMPs-2 e -9 purificadas humanas, por zimografia. Posteriormente, somente as concentrações (1,5; 3,5 e 5%) que apresentaram capacidade de inibição total de ambas MMPs foram utilizadas para avaliar sua capacidade remineralizadora em substrato dentinário submetido ao desafio cariogênico artificial, através da dureza de superfície (DS) e longitudinal (DL). No estudo 2, baseado nos resultados anteriores, foi avaliada a capacidade do STMP à 1,5% associado ou não a soluções de NaF ou Ca(OH)2 em melhorar a resistência de união à dentina de um sistema adesivo universal pelo teste de microtração. Desta forma, estes estudos sugerem que o STMP à 1,5% apresenta-se como um inibidor eficaz da degradação do colágeno mediada por MMPs-2 e -9 humanas purificadas. Além disso, a dentina humana desmineralizada e tratada com STMP à 1,5% suplementada com Ca(OH)2 pode induzir à remineralização. Assim, o uso de STMP pode ser introduzido como uma nova estratégia que combina inibição enzimática e potencial de remineralização, reestabelecendo condições favoráveis a partir de uma dentina afetada. Estas evidências sustentam perspectivas de terapias para reestruturar a dentina e propor estratégias clínicas factíveis e promissoras.(AU)

Fluoride gel supplemented with sodium hexametaphosphate reduces enamel erosive wear in situ.

OBJECTIVE: This study evaluated the effect of fluoride gels, supplemented or not with sodium hexametaphosphate (HMP), on enamel erosive wear in situ. METHODS: Twelve healthy volunteers wore palatal appliances containing four bovine enamel discs. Subjects were randomly allocated into four experimental phases (double-blind, crossover protocol) according to the gels: Placebo (no fluoride or HMP), 1% NaF, 2% NaF, and 1% NaF+9% HMP. Enamel discs were selected after polishing and surface hardness analysis, and treated only once with the respective gels prior to each experimental phase. Erosion (ERO) was performed by extra-oral immersion of the appliance in 0.05M citric acid, pH 3.2 (four times/day, five minutes each, 5 days). Additional abrasion (ERO+ABR) was produced on only two discs by toothbrushing with fluoridated dentifrice after ERO (four times/day, 30s, 5 days). The specimens were submitted to profilometry and hardness analysis. The results were analyzed by two-way ANOVA and the Student-Newman-Keuls test (p<0.05). RESULTS: The 1% NaF+9% HMP gel promoted significantly lower enamel wear for ERO compared to the other groups, being statistically lower than 1% NaF and Placebo for ERO+ABR. Similarly, the lowest values of integrated lesion area were found for 1% NaF+9% HMP and 2% NaF, respectively, for ERO and ERO+ABR. CONCLUSION: The addition of HMP to the 1% NaF gel promoted greater protective effect against ERO and ERO+ABR compared to the 1% NaF gel, achieving similar protective levels to those seen for the 2% NaF gel. CLINICAL SIGNIFICANCE: Gel containing 1% NaF+9% HMP showed a high anti-erosive potential, being a safer alternative when compared to a conventional 2% NaF gel.

Surface degradation of lithium disilicate ceramic after immersion in acid and fluoride solutions.

PURPOSE: To analyze whether immersion in sodium fluoride (NaF) solutions and/or common acidic beverages (test solutions) would affect the surface roughness or topography of lithium disilicate ceramic. METHODS: 220 ceramic discs were divided into four groups, each of which was subdivided into five subgroups (n = 11). Control group discs were immersed in one of four test beverages for 4 hours daily or in artificial saliva for 21 days. Discs in the experimental groups were continuously immersed in 0.05% NaF, 0.2% NaF, or 1.23% acidulated phosphate fluoride (APF) gel for 12, 73, and 48 hours, respectively, followed by immersion in one of the four test beverages or artificial saliva. Vickers microhardness, surface roughness, scanning electron microscopy (SEM) associated with energy dispersive spectroscopy, and atomic force microscopy (AFM) assessments were made. Data were analyzed by nested analysis of variance (ANOVA) and Tukey's test (α = 0.05). RESULTS: Immersion in the test solutions diminished the microhardness and increased the surface roughness of the discs. The test beverages promoted a significant reduction in the Vickers microhardness in the 0.05% and 0.2% NaF groups. The highest surface roughness results were observed in the 0.2% NaF and 1.23% APF groups, with similar findings by SEM and AFM. Acidic beverages affected the surface topography of lithium disilicate ceramic. Fluoride treatments may render the ceramic surface more susceptible to the chelating effect of acidic solutions.

An in vitro study to determine the effect of Terminalia chebula extract and its formulation on Streptococcus mutans.

AIM: Many weapons are available in the arsenal of a dental professional to combat dental caries, which is almost ubiquitously present. From a public health perspective, most of these weapons are far from being an ideal drug. Hence, there is a demand for better and effective antibacterial agents. This factor stimulated the process of the present study. The aim of the study was to determine the effect of ethanol extract of Terminalia chebula on Streptococcus mutans. MATERIALS AND METHODS: Dried ripe fruits of Terminalia chebula were procured and powdered. Physical tests were done to estimate purity of the fruit powder. Hydroethanolic and aqueous extracts were prepared according to standard procedures. Minimum inhibitory concentration of the extracts was determined by tube dilution method and confirmed by agar dilution method. The effect of the hydroethanolic extract on sucrose induced adhesion, glucan-induced aggregation and on glycolysis of Streptococcus mutans was also assessed. Preservative, gelling agent and sweetener were added in suitable quantities to the ethanol extract, and mouthrinse was formulated. Minimum inhibitory concentration of the formulation was also determined. RESULTS: Yield was better in case of aqueous extract. The Minimum inhibitory concentration of hydroethanolic extract was determined to be 2.5%. Minimum inhibitory concentration of the aqueous extract was determined to be 10%. Hydroethanolic extract of Terminalia chebula (2.5%) inhibited sucrose induced adherence and aggregation of Streptococcus mutans in vitro. CONCLUSION: The mouthrinse formulated from ethanol extract of Terminalia chebula demonstrated substantial antibacterial activity and could be used as an effective anticaries agent. CLINICAL SIGNIFICANCE: Terminalia chebula mouthrinse can be effectively used in clinical practice as an anticaries mouthrinse with additional benefit being that it is safe and economical.

Longitudinal evaluation of fluoride levels in nails of 18-30-month-old children that were using toothpastes with 500 and 1100 µg F/g.

OBJECTIVES: This study aimed to evaluate the fluoride concentration in the fingernails and toenails of children aged 18-30 months during use of fluoride-containing toothpastes supplemented with calcium glycerophosphate (CaGP) or sodium trimetaphosphate (TMP). METHODS: According to the toothpaste used, children (n = 56) were randomly assigned into three groups: 500 µg F/g with 1% TMP, 500 µg F/g with 0.25% CaGP, and 1100 µg F/g. Fingernails and toenails were collected monthly over a period of 330 days, from the beginning of toothpaste use. Fluoride concentration in the water consumed by the volunteers and fluoride intake from diet and toothpaste were also determined. Fluoride analyses were performed with the electrode after hexamethyldisiloxane-facilitated diffusion or by the direct method, according to the samples. Data passed normality and homoscedasticity tests and were analyzed by 2-way analysis of variance (anova) and 1-way anova followed by Student-Newman-Keuls test (P < 0.05). RESULTS: Fluoride levels in the fingernails and toenails as well as fluoride intake from toothpaste were similar for the groups treated with 500 µg F/g with 1% TMP and 500 µg F/g with 0.25% CaGP toothpastes, but significantly lower than the 1100 µg F/g group (P < 0.05). No significant differences were noted among the groups regarding fluoride intake from diet and that by water consumed by the volunteers (P > 0.05). CONCLUSION: The results of the longitudinal study suggest that the level of fluoride present in nails was lower with the use of toothpastes with a low fluoride concentration.

Effect of trimetaphosphate and fluoride association on hydroxyapatite dissolution and precipitation in vitro.

The present study analyzed the action of sodium trimetaphosphate (TMP) and/or fluoride on hydroxyapatite. Hydroxyapatite powder was suspended in different solutions: deionized water, 500 µg F/mL, 1,100 µg F/mL, 1%TMP, 3%TMP, 500 µg F/mL plus 1%TMP and 500 µg F/mL plus 3%TMP. The pH value of the solutions was reduced to 4.0 and after 30 min, raised to 7.0 (three times). After pH-cycling, the samples were analyzed by X-ray diffraction and infrared spectroscopy. The concentrations of calcium fluoride, fluoride, calcium and phosphorus were also determined. Adding 1% or 3% TMP to the solution containing 500 µg F/mL produced a higher quantity of calcium fluoride compared to samples prepared in a 1,100 µg F/mL solution. Regarding the calcium concentration, samples prepared in solutions of 1,100 µg F/mL and 500 µg F/mL plus TMP were statistically similar and showed higher values. Using solutions of 1,100 µg F/mL and 500 µg F/mL plus TMP resulted in a calcium/phosphorus ratio close to that of hydroxyapatite. It is concluded that the association of TMP and fluoride favored the precipitation of a more stable hydroxyapatite.

Effect of sodium trimetaphosphate on hydroxyapatite solubility: an in vitro study.

This study evaluated the effect of different concentrations of sodium trimetaphosphate (TMP) with and without fluoride (F) on the concentration of calcium (Ca), phosphorus (P) and F in hydroxyapatite (HA). Synthetic HA powder (0.15 g) was suspended (n=6) in solutions (75 mL) of TMP at 0%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 2.0%, 4.0%, 6.0%, 8.0% and 10% concentrations in the presence and absence of 100 ppm F and subjected to a pH-cycling process. The precipitates were filtrated, dried at 70° C for 24 h and ground onto a fine powder. The concentrations of F (KOH (CaF2) and HCl (FA) soluble), Ca (Arsenazo III), and P (molybdate method) in HA were determined. The Ca P, and Ca/P ratio data were subjected to Tukey's test and the F data were subjected to Student-Newman-Keuls test (p<0.05). The addition of TMP to the samples reduced F deposition to 98% (p<0.001). The groups containing 100 ppm F and 0.4% or 0.6% TMP exhibited a higher Ca concentration than the group containing only 100 ppm F (p<0.05). Furthermore, the HA treated with 0.2% and 0.4% TMP and 100 ppm F showed a higher Ca/P ratio than the other groups (p<0.001). In conclusion, TMP at 0.2%, 0.4% and 0.6% concentrations combined with F seemed to be able to precipitate HA with low solubility. However, especially at high concentrations, TMP interferes with F deposition on HA.

Effect of open-sandwich vs. adhesive restorative techniques on enamel and dentine demineralization: an in situ study.

OBJECTIVES: To assess in situ the effect of different restorative techniques used with fluoride-releasing materials on enamel and dentine demineralization in the presence of a cariogenic challenge. METHODS: Thirty human molars were prepared for 60 Class V cavities, with enamel and dentine margins. The teeth were divided into four groups (n=15): L1 - open sandwich technique with a conventional glass ionomer cement (GIC), L2 - open sandwich technique with a resin-modified GIC, A1 - total-etch bonding with a fluoride-containing adhesive, A2 - total-etch bonding with a nonfluoride-containing adhesive. All the cavities were restored with a nanofilled composite. Fifteen volunteers used appliances containing one specimen from each group. The cariogenic challenge was carried out with a 20% sucrose solution 8×/day for 7 days. The specimens were sectioned for microhardness test and EDS analysis at different depths below the enamel and dentine margins (25, 50 and 100µm) and distances from the tooth-restoration interfaces (25 and 75µm). The data were analyzed by ANOVA and Games-Howell test (α=5%). RESULTS: Both GICs produced higher hardness in enamel at all depth-and-distance combinations, but only L1 produced higher hardness in dentine (p<0.05). L2 and A1 exhibited similar dentine hardness at 25µm distance for all depths (p>0.05). L1 demonstrated significantly higher amounts of calcium in dentine than the other groups, but had similar amounts in enamel to L2 and A1. CONCLUSIONS: The open sandwich technique using conventional GIC proved more effective in reducing enamel and dentine demineralization at depths of up to 100µm under a cariogenic challenge. CLINICAL SIGNIFICANCE: Conventional GICs should be considered the materials of choice for lining of cavities not having all margins in enamel, particularly using the open sandwich technique.

Laboratory and human studies to estimate anticaries efficacy of fluoride toothpastes.

Much more than mechanical biofilm removal, toothbrushing with fluoride toothpastes is an effective way of increasing the availability of fluoride in the oral cavity to reduce demineralization and enhance remineralization of enamel and dentine. These effects of fluoride toothpastes have been estimated by a wide range of laboratory and human studies, which have helped to develop anticaries effective formulations and understand their mechanism of action. These studies have focused on the availability of fluoride in the toothpaste formulations, its bioavailability in saliva and remnants of disturbed biofilm, its reaction with the dental substrate to form loosely bound reservoirs as well as the ultimate reduction of mineral loss and increase in mineral and fluoride content of caries lesions. The specifics of these modes of action and their application in in vitro, in situ and in vivo preclinical tests is presented and discussed.

After-brush rinsing protocols, frequency of toothpaste use: fluoride and other active ingredients.

The intra-oral retention or substantivity of active ingredients in toothpastes is important for their effectiveness, and this is influenced by product-related and user-related factors. Product-related factors include the formulation and the compatibility of active and other agents in the toothpaste and the concentration of the active ingredient. User-related factors include biological aspects such as salivary flow and salivary clearance, and behavioural aspects, such as frequency and duration of brushing, amount of toothpaste used and post-brushing rinsing behaviour. To date, product-related factors have dominated the research agenda for toothpastes, but user-related factors have the potential to significantly enhance or reduce the effectiveness of toothpaste. In this chapter, we will focus on two of the user-related factors that have been most widely studied: (1) frequency of toothbrushing and (2) post-brushing rinsing behaviour. We will then provide an overview of how evidence on these two behaviours has been used to produce guidance both for the profession and for the public, and make suggestions for the future direction of research in this area.

Effect of Sodium Trimetaphosphate on Hydroxyapatite Solubility: An In Vitro Study

This study evaluated the effect of different concentrations of sodium trimetaphosphate (TMP) with and without fluoride (F) on the concentration of calcium (Ca), phosphorus (P) and F in hydroxyapatite (HA). Synthetic HA powder (0.15 g) was suspended (n=6) in solutions (75 mL) of TMP at 0%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 2.0%, 4.0%, 6.0%, 8.0% and 10% concentrations in the presence and absence of 100 ppm F and subjected to a pH-cycling process. The precipitates were filtrated, dried at 70° C for 24 h and ground onto a fine powder. The concentrations of F (KOH (CaF2) and HCl (FA) soluble), Ca (Arsenazo III), and P (molybdate method) in HA were determined. The Ca P, and Ca/P ratio data were subjected to Tukey's test and the F data were subjected to Student-Newman-Keuls test (p<0.05). The addition of TMP to the samples reduced F deposition to 98% (p<0.001). The groups containing 100 ppm F and 0.4% or 0.6% TMP exhibited a higher Ca concentration than the group containing only 100 ppm F (p<0.05). Furthermore, the HA treated with 0.2% and 0.4% TMP and 100 ppm F showed a higher Ca/P ratio than the other groups (p<0.001). In conclusion, TMP at 0.2%, 0.4% and 0.6% concentrations combined with F seemed to be able to precipitate HA with low solubility. However, especially at high concentrations, TMP interferes with F deposition on HA.

Este estudo avaliou o efeito de diferentes concentrações de trimetafosfato de sódio (TMP) com e sem fluoreto (F) nas concentrações de cálcio (Ca), fósforo (P) e F na hidroxiapatita (HA). Pó de HA sintético (0,15 g) foi suspenso (n=6) em soluções (75 mL) de TMP com concentrações de 0%, 0,1%, 0,2%, 0,4%, 0,6%, 0,8%, 1,0%, 2,0%, 4,0%, 6,0%, 8,0% e 10% na presença ou na ausência de 100 ppm F e foram submetidas ao processo de ciclagem de pH. O precipitado foi filtrado seco a 70°C por 24 h e triturado em um pó fino. As concentrações de F (solúvel em KOH: CaF2, e em HCl: FA), Ca (Arsenazo III) e P (método do molibdato) foram determinadas na HA. Os dados de Ca, P e de proporção Ca/P foram submetidos ao teste de Tukey e os dados de F ao teste Student-Newman-Keuls (p<0,05). A adição de TMP reduziu a deposição de F em 98% (p<0,001). Os grupos contendo 100 ppm F e TMP 0,4% e 0,6% apresentaram maiores concentrações de Ca do que o grupo contendo somente 100 ppm F (p<0,05). Além disso, a HA tratada com 0,2% e 0,4% de TMP e 100 ppm F apresentou maiores proporções Ca/P em relação aos demais grupos (p<0,001). Em conclusão, TMP nas concentrações de 0,2%, 0,4% e 0,6% quando associado ao F é capaz de precipitar uma HA com menor solubilidade. Entretanto, especialmente em altas concentrações, TMP interfere com a deposição de F na HA.

Topical laser application enhances enamel fluoride uptake and tribological properties.

Topical fluoride treatment prevents dental caries. However, the resulting calcium-fluoride-like deposits are soft and have poor wear resistance; therefore, frequent treatment is required. Lasers quickly heat surfaces and can be made portable and suitable for oral remedies. We examined the morphology, nanohardness, elastic modulus, nanowear, and fluoride uptake of fluoride-treated enamel followed by CO2 laser irradiation for 5 and 10 sec, respectively. We found that laser treatments significantly increased the mechanical properties of the calcium-fluoride-like deposits. The wear resistance of the calcium-fluoride-like deposits improved about 34% after laser irradiation for 5 sec and about 40% following irradiation for 10 sec. We also found that laser treatments increased fluoride uptake by at least 23%. Overall, laser treatment significantly improved fluoride incorporation into dental tissue and the wear resistance of the protective calcium-fluoride layer.

Use of glass ionomer cement containing antibiotics to seal off infected dentin: a randomized clinical trial.

Dental materials with antibacterial properties can prevent the harmful effects caused by oral cariogenic bacteria. This double-blind controlled clinical trial evaluated the performance of a glass ionomer cement (GIC) added with antibiotics for sealing infected dentin in atraumatic restorations of primary molars. The study enrolled 45 children (45 teeth) between 5 and 8 years of age, of both genders, divided into two groups: GC (n=22), where cavities were lined with a conventional GIC (Vidrion F) and GA (n=23), with cavities lined with Vidrion F added with 1% each of metronidazole, ciprofloxacin and cefaclor antibiotic. Both groups were restored with Ketac Molar Easymix. Molars with carious lesions on the inner half of dentin without clinical or radiographic pulp damage were selected. Patients were evaluated clinically (pain, fistulas or mobility) and radiographically (area of caries, periapical region and furcation) after 1, 3, 6 and 12 months. For statistical analysis, chi-squared or Fisher's exact tests were used with a 5% significance level. GA (82.6-95.7%) had better results than GC (12.5-36.4%) in all evaluations (p<0.05) and the difference in the success rate was 46.2-72.5% higher for GA. The use of the antibiotic-containing GIC liner on infected dentin proved satisfactory when applied in deciduous teeth.

Effects of fluoride on in vitro enamel demineralization analyzed by ¹9F MAS-NMR.

The mechanistic action of fluoride on inhibition of enamel demineralization was investigated using (19)F magic angle spinning nuclear magnetic resonance (MAS-NMR). The aim of this study was to monitor the fluoride-mineral phase formed on the enamel as a function of the concentration of fluoride ions [F(-)] in the demineralizing medium. The secondary aim was to investigate fluorapatite formation on enamel in the mechanism of fluoride anti-caries efficacy. Enamel blocks were immersed into demineralization solutions of 0.1 M acetic acid (pH 4) with increasing concentrations of fluoride up to 2,262 ppm. At and below 45 ppm [F(-)] in the solution, (19)F MAS-NMR showed fluoride-substituted apatite formation, and above 45 ppm, calcium fluoride (CaF2) formed in increasing proportions. Further increases in [F(-)] caused no further reduction in demineralization, but increased the proportion of CaF2 formed. Additionally, the combined effect of strontium and fluoride on enamel demineralization was also investigated using (19)F MAS-NMR. The presence of 43 ppm [Sr(2+)] in addition to 45 ppm [F(-)] increases the fraction of fluoride-substituted apatite, but delays formation of CaF2 when compared to the demineralization of enamel in fluoride-only solution.

Adhesive microbeads for the targeting delivery of anticaries agents of vegetable origin.

The formulation of quinic acid, a food constituent demonstrating potential anticaries and antigingivitis properties, was investigated in an adhesive microparticulate delivery system with the goal of improving its effect by prolonging its residence time at the site of action. Alginate and chitosan were selected as mucoadhesive polymers. The microspheres were prepared by coacervation. Different types of alginates, polymers blends and crosslinking agent concentrations were considered and evaluated. The best results in terms of encapsulation efficiency, in vitro active agent release profile and in vitro adhesive properties, both to oral mucosa and to teeth surface, were obtained with a blend of Alginate Protanal LF200S: Alginate Protanal LF120LS 1:1.5 w/w, 0.1M CaCl(2), and chitosan coating, prepared by a one-step complex coacervation method. This microparticulate delivery system showed prolonged release of quinic acid, and could be used as an active component in chewing gums or mouthwashes for both caries and gingivitis prevention.

Effect of resin composites with sodium trimetaphosphate with or without fluoride on hardness, ion release and enamel demineralization.

PURPOSE: To evaluate the effect of the addition of sodium trimetaphosphate (TMP) with or without fluoride on enamel demineralization, and the hardness and release of fluoride and TMP of resin composites. METHODS: Bovine enamel slabs (4 x 3 x 3 mm) were prepared and selected based on initial surface hardness (n = 96). Eight experimental resin composites were formulated, according to the combination of TMP and sodium fluoride (NaF): TMP/NaF-free (control), 1.6% sodium fluoride (NaF), and 1.5%, 14.1% and 36.8% TMP with and without 1.6% NaF. Resin composite specimens (n = 24) were attached to the enamel slabs with wax and the sets were subjected to pH cycling. Next, surface and cross-sectional hardness and fluoride content of enamel as well as fluoride and TMP release and hardness of the materials were evaluated. Data were statistically analyzed using ANOVA (P < 0.05). RESULTS: The presence of fluoride in enamel was similar in fluoridated resin composites (P > 0.05), but higher than in the other materials (P < 0.05). The combination of 14.1% TMP and fluoride resulted in less demineralization, especially on lesion surface (P < 0.05). The presence of TMP increased fluoride release from the materials and reduced their hardness.