Comparative Effect of Calcium Mesoporous Silica Versus Calcium and/or Fluoride Products on the Reduction of Erosive Tooth Wear and Abrasive Enamel Lesion

Abstract Objective: To evaluate the effect of a calcium nanocompound on the reduction of erosive tooth wear and abrasion. Material and Methods: Bovine enamel specimens (BE), were randomly assigned to the following groups (n = 10): G1 = Calcium mesoporous silica nanoparticles (Ca2+MSNs); G2 = casein phosphopeptide-amorphous calcium phosphate (CPP-ACP, 2% CPP-ACP, GC®); G3 = casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP, 2% CPP-ACP + 900 ppm F-, GC®); G4 = sodium fluoride NaF (900 ppm F-, positive control); and G5 = distilled and deionized water (negative control). Each product was applied to the exposed area for one minute, three times per day for three consecutive days, and followed by the immersion of the specimens in Sprite Zero™ - a low-pH solution (2.58) for five minutes (Coca-Cola™). After the first and last erosive challenges of the day, the specimens were submitted to abrasion in a toothbrush machine for 15 seconds (200 g/BE). The specimens were analysed using 3D non-contact optical profilometry, with tooth structure loss (TSL) measurements and scanning electron microscopy (SEM). TSL values were analysed by Kruskal-Wallis and Mann-Whitney tests (p<0.05). Results: There were no significant differences between G1 (10.95 µm) and G3 (10.80 µm) treatments for TSL values; however both resulted in significantly reduced TSL values compared with the G5 (16.00 µm) (p<0.05). The G4 (12.26 µm) showed no statistically significant difference when compared to the G5 (16.00 µm). The groups G1 and G3 presented higher surface preservation than the G5. Conclusion: Ca2+MSNs was effective for reducing tooth surface loss caused by erosive tooth wear and abrasion.

Influence of desensitizers agents on the dentin bond strength after one-year water storage

Aim: Evaluate the effect of adhesives systems combined with desensitizer agents on the microtensile bond strength (µTBS) of a composite resin to dentin. Methods: Cervical dentin of thirty-two human molars were used to simulate hypersensitivity areas. The teeth were divided into four groups (n=8), according to the type of adhesive system and desensitizer agents. No desensitizer was used in the control (Clearfil SE Bond ­ CS). Two experimental groups were pretreated with either MS Coat Bond (MS) or Biofluorid 12 (BF) immediately prior to bonding with CS. The last group corresponded to Gluma Comfort Bond + Desensitizer (GC) application. After dentin treatments, a composite block was built-up on dentin surface and after 24 hours teeth were serially sectioned to obtain bonded bean specimens. Beams were stored in water for 24 hours or one year. Subsequently, the specimens were submitted to the µTBS test. Data were analyzed by two-way mixed ANOVA and Bonferroni's test (α = 0.05). Results: At 24 hours, there was no significant difference in µTBS among groups. However, at one year, dentin treated with MS or BF demonstrated significantly lower µTBS of CS to dentin compared to control and GC, which kept their µTBS stable. Conclusion: The effect of MS and BF desensitizer agents on the µTBS of CS to dentin did not reduce the µTBS at 24 hours, but it decreases significantly after one year

In Situ Effect of Intra-Oral Application of Pastes Containing CPP-ACP or CPP-ACPF Against Initial Enamel Erosion

Objective: To evaluate in situ the effect of toothpastes containing casein phosphopeptide - amorphous calcium phosphate (CPP-ACP) and casein phosphopeptide-amorphous calcium phosphate associated to fluoride (CPP-ACPF) on initial erosion prevention. Material and Methods: Bovine enamel blocks (n = 192) were randomly assigned into 4 phases according to the baseline surface hardness: GI: CPP-ACP Paste (MI Paste™), GII: CPP-ACPF Paste (MI Paste Plus™), GIII: Fluoridated paste and GIV: Placebo Paste. In each of the 4 crossover phases, twelve volunteers wore intraoral palatal appliances containing 4 enamel blocks for 2 hours, then the tested treatments were applied intraorally (3 min) and the appliance was maintained in the mouth for another 3 hours. After, the appliances were removed and immersed in hydrochloric acid (0.01 M, pH 2.3) for 30 seconds to promote erosive demineralization. The final surface hardness was evaluated and percentage of surface hardness loss was calculated. The data were analyzed by ANOVA and Tukey's test (α = 5%). Results: The application of CPP-ACP paste, independent of fluoride content, resulted in significant lower enamel hardness loss (GI: 9.26% ±3.48 and GII: 9.14% ±1.73) compared to NaF (GIII: 15.5% ± 3.94) and placebo (GIV: 16.7% ± 4.07) pastes, which did not show difference between them. Conclusion: The CPP-ACP pastes were able to reduce initial erosive demineralization in relation to fluoride and placebo pastes. Nevertheless the formulation of CPP-ACP with fluoride did not provide an additional benefit.

Effect of iontophoresis on fluoride uptake in enamel with artificial caries lesion

Abstract: Iontophoresis is a noninvasive technique, based on the application of a constant low-intensity electric current to facilitate the release of a variety of drugs, whether ionized or not, through biological membranes. The objective of this research was to evaluate the effect of iontophoresis using different electric current intensities on the uptake of fluoride in dental enamel with artificial caries lesions. In this in vitro operator-blind experiment, bovine enamel blocks (n = 10/group) with caries-like lesions and predetermined surface hardness were randomized into 6 groups: placebo gel without fluoride applied with a current of 0.8 mA (negative control), 2% NaF gel without application of any current, and 2% NaF gel applied with currents of 0.1, 0.2, 0.4 and 0.8 mA. Cathodic iontophoresis was applied for 4 min. The concentration of loosely bound fluoride (calcium fluoride) and firmly bound fluoride (fluorapatite) was determined. The results were analyzed by the nonparametric Kruskal-Wallis and Dunn tests. Iontophoresis at 0.8 mA, combined with the application of fluoridated gel (2% NaF), increased fluoride uptake in enamel with caries-like lesions, as either calcium fluoride or fluorapatite.

Excessive fluoride inducing calcium overload and apoptosis of ameloblasts / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the effect of excessive fluoride on calcium overload and apoptosis in cultured rat ameloblasts in vitro.</p><p><b>METHODS</b>Logarithmic-phase ameloblasts (HAT-7) were treated with 0, 0.4, 0.8, 1.6, 3.2, and 6.4 mmol · L(-1) sodium fluoride (NaF) solution. Cell activities were detected by using a Cell Counting Kit 8 (CCK-8) assay after 48 h of treatment. The effect of fluoride on cell apoptosis was analyzed by using flow cytometry. Excessive fluoride-induced calcium concentration and calreticulin expression changes in ameloblasts were detected by using laser scanning confocal microscopy, Western blot analysis, and real-time quantitative polymerase chain reaction.</p><p><b>RESULTS</b>NaF inhibited ameloblast activity at 1.6, 3.2, and 6.4 mmol · L(-1) (dose-dependent) after 48 h of induction. The Ca2+ fluorescence intensity of HAT-7 cells incubated with 1.6 and 3.2 mmol · L(-1) NaF was higher than that in the control group. The fluoride-induced early-stage apoptosis of ameloblasts after 48 h of induction and the early-stage apoptosis rate was positively correlated with fluoride concentration. Calreticulin mRNA expression in HAT-7 cells was higher than that in the control group after 48 h of incubation with 0.8, 1.2, and 1.6 mmol · L(-1) NaF.</p><p><b>CONCLUSION</b>Excessive fluoride-induced calcium overload in ameloblasts and further caused endoplasmic reticulum stress-mediated apoptosis.</p>

Therapeutic effect of two fluoride varnishes on white spot lesions: a randomized clinical trial

The aim of this randomized clinical trial study was to evaluate the therapeutic effect of two varnish formulations (G1 = 5 percent NaF, G2 = 6 percent NaF + 6 percent CaF2) on the remineralization of white spot lesions (WSL). The sample was composed of 15 (7- to 12-year-old) children with 45 active WSL in anterior permanent teeth. The children were randomly divided into two groups providing 22 lesions for G1 and 23 for G2. The children were submitted to weekly varnish applications 4 times. The WSL were evaluated twice: baseline and on week 4. Maximum lesion dimensions (mesiodistal and incisogingival) were measured in millimeters and classified in four grades of size. WSL were also assessed regarding lesion activity by one calibrated examiner. The Pearson chi-square and Fisher's exact tests were used (P < 0.01). WSL reductions were observed in both varnish groups (Chi-square = 0.15, d.f. = 1, P = 0.90), and with similar magnitude (in mm): 1.19 and 1.29 for G1 and G2, respectively. Thirty-six WSL (15 in G1 and 21 in G2) were classified as inactive on week 4, reaching an overall value of 80 percent. No difference was observed between G1 and G2 regarding activity scores (Fisher's exact test, p > 0.01). It was concluded that after 4 applications the two varnish formulations tested produced similar clinical effects, indicating the reduction and the control of carious activity in most WSL.

Effect of fluoride-containing desensitizing agents on the bond strength of resin-based cements to dentin

OBJECTIVE: The objective of this study was to evaluate the effect of desensitizing agents containing different amounts of fluoride on the shear bond strength of a dual polymerized resin cement and a resin-modified glass ionomer cement (RMGIC) to dentin. MATERIAL AND METHODS: One hundred human molars were mounted in acrylic resin blocks and prepared until the dentin surface was exposed. The specimens were treated with one of four desensitizing agents: Bifluorid 12, Fluoridin, Thermoline and PrepEze. The remaining 20 specimens served as untreated controls. All groups were further divided into 2 subgroups in which a dual polymerized resin cement (Bifix QM) or a resin-modified glass ionomer cement (AVANTO) was used. The shear bond strength (MPa) was measured using a universal testing machine at a 0.5 mm/min crosshead speed. The data were analyzed statistically with a 2-way ANOVA, Tukey HSD test and regression analysis (α=0.05). The effect of the desensitizing agents on the dentin surface was examined by scanning electron microscopy. RESULTS: The fluoride-containing desensitizing agents affected the bond strength of the resin-based cements to dentin (p<0.001). PrepEze showed the highest bond strength values in all groups (p<0.001). CONCLUSION: Regression analysis showed a reverse relation between bond strength values of resin cements to dentin and the amount of fluoride in the desensitizing agent (p<0.05).

Urinary fluoride output in children following the use of a dual-fluoride varnish formulation

OBJECTIVE: This study evaluated the bioavailability of fluoride after topical application of a dual-fluoride varnish commercially available in Brazil, when compared to DuraphatTM. MATERIAL AND METHODS: The urinary fluoride output was evaluated in seven 5-year-old children after application of the fluoride varnishes, in two different phases. In the first phase (I), children received topical application of the fluoride varnish Duofluorid XII (2.92 percent fluorine, calcium fluoride + 2.71 percent fluorine, sodium fluoride, FGM TM). After 1-month interval (phase II), the same amount (0.2 mL) of the fluoride varnish Duraphat (2.26 percent fluorine, sodium fluoride, ColgateTM) was applied. Before each application all the volunteers brushed their teeth with placebo dentifrice for 7 days. Urinary collections were carried out 24 h prior up to 48 h after the applications. Fluoride intake from the diet was also estimated. Fluoride concentration in diet samples and urine was analyzed with the fluoride ion-specific electrode and a miniature calomel reference electrode coupled to a potentiometer. Data were tested by ANOVA and Tukey's post hoc test (p<0.05). RESULTS: There were significant differences in the urinary fluoride output between phases I and II. The use of Duofluorid XII did not significantly increase the urinary fluoride output, when compared to baseline levels. The application of Duraphat caused a transitory increase in the urinary fluoride output, returning to baseline levels 48 h after its use. CONCLUSIONS: The tested varnish formulation, which has been shown to be effective in in vitro studies, also can be considered safe.

Anticaries potential of a fluoride mouthrinse evaluated in vitro by validated protocols

This blind and randomized study tested in vitro, using validated protocols, the anticaries potential of an experimental fluoride mouthrinse. One-hundred enamel slabs, half sound and half with caries-like lesions (carious), all with known surface microhardness (SMH), were submitted to 3 treatment groups: A) a placebo mouthrinse (negative control); B) a positive control mouthrinse containing 0.05 percent NaF; and C) an experimental formulation containing 0.05 percent NaF and cetylpyridinium chloride as an antibacterial substance. To evaluate the formation of F products on enamel, sound (n=10) and carious (n=10) slabs were treated with the formulations during 10 min and loosely and firmly-bound F formed in enamel were determined after extraction with alkali and acid, respectively. To evaluate the inhibition of enamel demineralization, sound enamel slabs (n=10) were treated with the mouthrinse formulations 2x/day during 1 min and subjected to a pH-cycling regimen simulating a cariogenic challenge (demineralization). To evaluate enamel remineralization, the carious slabs (n=10) were submitted to the treatments 3x/day and subjected to a pH-cycling model simulating a remineralizing condition. After 8 days, enamel SMH was determined again and the percentage of SMH loss or SMH recovery was calculated for the sound and carious slabs, respectively. The experimental formulation was superior to the negative control (p<0.05) and equivalent to the positive control (p>0.05) in the formation of F products in enamel, and in the inhibition of enamel demineralization and enhancement of remineralization. These data suggest that the tested experimental fluoride mouthrinse has anticaries potential.

Este estudo in vitro, cego e randomizado avaliou o potencial anticárie de uma formulação experimental de enxaguatório fluoretado (F), usando protocolos previamente validados. Blocos de esmalte (120), 60 hígidos e 60 com lesão artificial de cárie, com microdureza de superfície (MDS) conhecida, foram submetidos a 3 grupos de tratamentos: A) Enxaguatório placebo (controle negativo); B) Controle positivo contendo NaF 0,05 por cento e C) Uma formulação experimental contendo NaF 0,05 por cento e cloreto de cloreto de cetil-piridínio como antibacteriano. Para testar a capacidade de formação de produtos fluoretados no esmalte, blocos hígidos (n=10) e cariados (n=10) foram tratados durante 10 min e os fluoretos fracamente e fortemente ligados formados foram determinados após extração com álcali e ácido, respectivamente. Para avaliar a inibição da desmineralização do esmalte, os blocos hígidos (n=10) foram tratados com as formulações 2 x/dia durante 1 min e submetidos a um modelo de ciclagem de pH, simulando o processo de desmineralização. Para avaliar a ativação da remineralização do esmalte, os blocos com lesões de cárie (n=10) foram tratados 3 x/dia e submetidos a um modelo de ciclagens de pH, simulando uma condição de remineralização. Após 8 dias, a MDS do esmalte foi novamente determinada e as porcentagens de sua redução ou aumento foram calculadas, respectivamente para os blocos hígidos ou com lesão de cárie. A formulação experimental foi superior ao controle negativo (p<0,05) e equivalente ao positivo (p>0,05), na formação de produtos fluoretados no esmalte e na inibição de sua desmineralização e ativação da remineralização. Conclui-se que o enxaguatório experimental apresenta fluoreto ativo com potencial para controlar cárie dental.

[Inhibitory effects of NaF-varnish and APF-gel on cariogenic bacteria: an in vitro study]

While there are multiple components of preventive programs developed for caries prevention in children, perhaps none is as important and effective as the appropriate use of fluoride. The primary caries preventive effects of fluoride result from its topical contact with enamel and through its antibacterial actions. Till now bulk of research exists which has compared the antibacterial effects of ordinary topical fluoride gels and solutions. Little or no evidence is seen to tell us which topical fluoride including varnishes is more antibacterial. We suggested further research about antibacterial effect of APF gel and NaF varnish against cariogenic microorganisms [streptococcus mutans and lactobacillus], so use of these may have benefit in reduction of caries. Comparison of inhibitory effect of NaF-varnish versus APF-gel on concentration of cariogenic bacteria [streptococcus mutans and lactobacillus], was the primary goal of this research. In this exprimental study, twenty premolars were sectioned buccolingually. With the use of "window method" certain surfaces of enamel were covered with APF-gel and NaF-varnish. Then, the number of streptococcus mutans and lactobacillus were counted after 18, 24 and 48 hours. In the "Disk diffusion" method the streptococcus mutans with the concentration of 108/ml and volume of 0.1cc were introduced to the M.S.Media culture after application of APF gel and NaF varnish. Then the inhibition zone, measured. Statistical analysis in this research was multilevel modeling. The comparison between gel and varnish after 18, 24 and 48 hours showed that gel has more effect than varnish over the number of lactobacillus. The difference with lactobacillus was statistically significant [p<0.005], but with streptococcus Mutans was not. APF gel was more effective [70.23%] than NaF varnish. Based on the obtained results, APF gel can be used with more thrust than NaF varnish in caries prevention

Efeito da ingestão de água na deposição de fluoreto de cálcio sobre o esmalte após aplicação tópica de gel fluoretado acidulado / Drinking water effect in calcium fluoride deposited on enamel after topical treatment with acidulated phosphate fluoride gel

O objetivo deste trabalho foi verificar a influência da ingestão de água de beber sobre a adsorção de fluoreto de cálcio no esmalte dental humano, após tratamento tópico com flúor-fosfato acidulado (FFA). Utilizaram-se 36 fragmentos de terceiros molares inclusos, inseridos em dispositivo intrabucal usado por uma voluntária. As amostras foram divididas aleatoriamente em dois grupos e removidas imediatamente, 15 minutos e 30 minutos, após tratamento com FFA durante quatro minutos. No grupo teste, a voluntária ingeriu água potável logo após o tratamento, e no grupo controle as amostras foram avaliadas depois do tratamento com fluoreto. Fez-se uso da metodologia proposta por Caslavska et. al (1975) para quantificar o produto reacional depositado na superfície do esmalte dental, e os resultados foram submetidos ao teste estatístico de Wilcoxon. Não foram observadas diferenças estatisticamente signifcantes entre os dois grupos, em qualquer dos tempos utilizados, favorecendo o ponto de vista de que a ingestão de água de beber, após o tratamento tópico com gel fluoretado, parece não interferir no produto reacional na superfície do esmalte dental.

Desmineralización-remineralización del esmalte dental / Demineralization-remineralization of the dental enamel

Si la estructura del diente se encuentra intacta, la desmineralización del esmalte dental puede ser reversible en las pequeñas lesiones de esmalte con un tratamiento no agresivo

Cementos de vidrio ionómero: liberación de flúor / Glass ionomer cements: fluoride release

Los cementos de vidrio ionómero (CVI) fueron introducidos en el mercado odontoestomatológico durante la década del setenta. Desde entonces, tanto su empleo como sus variaciones, mejoras e indicaciones han ido aumentando año tras año. Una de las características más importantes de los cementos de vidrio ionómero es la liberación de flúor, cualidad que no es superada actualmente por ningún otro material de restauración o cementado. A pesar de su frecuente empleo y su carácter preventivo gracias a esta propiedad, el mecanismo de liberación y de recarga de flúor, así como su efecto anticariogénico, no son totalmente conocidos, por lo que se siguen realizando múltiples e interesantes investigaciones a este respecto

Calcium fluoride uptake by human enamel after use of fluoridated mouthrinses / Incremento de CaF2 sobre o esmalte dental humano após utilização de soluções fluoretadas

O presente estudo teve como objetivo verificar, através da microscopia eletrônica de varredura (MEV), a formação e retenção de fluoreto de cálcio (CaF2) sobre a superfície do esmalte dental humano in situ após tratamento tópico com diferentes soluções fluoretadas disponíveis para bochecho no mercado, durante 5 e 10 minutos. Foram selecionados três produtos: solução fluoretada em pH neutro (Fluordent), solução fluoretada acidulada (Fluorgard) e uma solução fluoretada associada à clorexidina (Duplak). Cinqüenta e seis secções, obtidas de 14 terceiros molares hígidos, foram divididas em dois grupos: grupo A: 5 minutos de tratamento e grupo B: 10 minutos de tratamento. Através da análise dos resultados foi possível observar que as amostras tratadas por 5 min com solução associada à clorexidina demonstraram maior formação do produto semelhante ao CaF2. No grupo tratado por 10 min, as amostras em pH neutro demonstraram maior incremento de CaF2. De qualquer forma pôde-se perceber que o produto reacional foi formado e retido em quantidades significantes em todas as situações. Estes resultados demonstraram que os produtos utilizados neste experimento foram capazes de formar e depositar CaF2 sobre as superfícies do esmalte dental, podendo ser recomendados como coadjuvantes na prevenção e no controle da cárie dentária

A comparative evaluation of three fluoride varnishes: an in-vitro study.

This study was conducted to compare the caries preventive efficacy of Fluoritop - SR; the first fluoride varnish manufactured in India with Fluor Protector and Bifluorid 12, the two commercially available fluoride varnishes which have to be imported from other countries and are cost prohibitive. The demineralization inhibitory effects and the antibacterial effects on Streptococcus mutans were studied (in vitro). Calcium and Phosphorus dissolutions were estimated as a measure of the demineralization inhibitory effect. Antibiotic sensitivity tests using the serial tube dilution method and disk diffusion method were used to evaluate the antibacterial effects of the fluoride varnishes. Of the three varnishes, Fluor Protector was seen to exhibit the highest demineralization inhibitory effect, while Fluoritop-SR was found to be comparable to Bifluorid 12 in its caries protective effects.

Efectividad de dos barnices en la remineralización de la mancha blanca / Effectiveness of two varnishes in the remineralization of white spots

El objetivo de este trabajo es evaluar clínicamente la efectividad de la remineralización de las manchas blancas (MB) utilizando dos barnices fluorados. Se diagnosticaron 90 superficie sde MB. Los pacientes fueron divididos en tres grupos, GA: tratado con laca fluorada (FNa al 6 por ciento y F2Ca al 6 por ciento; Bifluorid 11/VOCO), GB: tratado con barniz fluorado (FNa al 5 por ciento, Fluoridin N 5/VOCO) y GC: control. Se realizaron tres topicaciones a los 0, 15 y 30 días La remineralización fue evaluada a los 15, 30 y 90 días. El grupo control no mostró remineralización en ninguno de los controles realizados (p menor 0.05. Para el tratamiento con laca (GA), se observó remineralización a los 15 días luego de la 1ra. topicación (p menor 0.01). Mientras que para el barniz (GB) la misma fue registrada a los 30 días (p menor 0.05). El tratamiento de las superficies dentarias con laca fluorada resulta ser más efectivo luego de la primera topicación con respecto al tratamiento con barniz fluorado

Análise in vitro do fluoreto no esmalte humano decíduo após tratamento com géis fluoretados / CCAF2 uptake on deciduos human enamel after fluoridated gels treatment in vitro

O objetivo deste estudo foi verificar, in vitro, a deposiçäo do fluoreto de cálcio (CaF²) após aplicaçäo de géis fluoretados neutro e acidulado sobre as superefícies hígida (H) e desmineralizada (D) do esmalte dental decíduo. Foram utilizadas 96 seçöes de esmalte, obtidas de 24 segundos molares decíduos, que foram divididas em quatro grupos: 1) HA, tratado com FFA; 2) DA, com FFA; 3) HN, com gel neutro; 4) DN, com gel neutro. As amostras foram tratadas durante 1 min e 4min. A deposiçäo de Caf² foi analisada pelo método de CASLAVSKA et al. (3) e os resultados, submetidos ao teste estatítico de Wilcoxon. Foi possível constatar a presença do Caf² após todos os tratamentos, porém ela foi maior no tempo de 4min. Quando foram comparados os dois produtos, tanto sobre os esmaltes H e D, a diferença foi estatisticamente significativa apenas com 4min de tratamento. Ao serem comparados os dois tipos de esmalte, näo foram observadas diferenças estatisticamente significativa, entre os dois produtos. Os resultados demonstraram que houve deposiçäo de Caf² decorrente da aplicaçäo tópica dos géis fluoretados na superfície dos dois tipos de esmalte, existindo uma relaçäo direta com o tempo de tratamento