Investigação do potencial erosivo de gomas de mascar não convencionais / Investigation the erosive potential of unconventional chewing gums

Objetivo: mensurar o potencial erosivo de gomas de mascar não convencionais disponíveis no mercado brasileiro. Material e método: estudo experimental (in vitro) de caráter quantitativo. Foram adquiridos oito sabores de gomas de mascar: Poosh® (pinta língua); Plutonita® (abraço congelante, dentada ardente, baba de bruxa e língua ácida); e TNT® (sangue, lava e tumba). Para análise da acidez, foram realizadas leituras em triplicata do pH e acidez titulável (AT), utilizando um potenciômetro e eletrodo combinado de vidro em soluções obtidas após a maceração das gomas de mascar em água duplamente deionizada. Nas soluções com valores de pH inferiores a 5,5, foi mensurada a AT adicionando-se alíquotas de 100 µLNaOH 0,1 M, até alcançar pH 5,5. Os resultados foram submetidos à Análise de Variância (ANOVA). As comparações das médias de pH e acidez titulável foram realizadas pelo teste de Tukey, com um nível de 5% de significância (p<0,05). Resultados: os valores de pH variaram entre 2,4 (abraço congelante) e 3,5 (baba de bruxa), diferin-do significantemente do controle (água mineral/pH=6,2). Os valores de acidez titulável variaram entre 628µL de NaOH 0,1 M (sangue) e 10700µL de NaOH 0,1 M (abraço congelante). A goma de mascar sabor abraço congelante apresentou o pH mais baixo e a mais elevada acidez titulável, diferindo significantemente dos demais sabores. Conclusões: as gomas de mascar avaliadas são ácidas, mas diferem quanto ao seu potencial erosivo. Seu consumo abusivo pode constituir um fator de risco para erosão dental.(AU)

Objective: to measure the erosive potential of non- -conventional chewing gums available in the Brazilian market. Material and methods: this is an in vitro study using the following flavors of chewing gums from the Brazilian market: Poosh® (tongue cleaner); Plutonita® (freezing hug, burning bite, witch slime and acid tongue); TNT® (blood, lava and tomb). For acidity analysis, pH and titratable acidity (TA) readings were performed in triplicate using a potentiometer and combined glass electrode in solutions obtained after maceration of the chewing gums in double deionized water. In solutions with pH values below 5.5, the TA was measured by adding aliquots of 100 µL 0.1 M NaOH, until pH 5.5 was reached. The results were submitted to Analysis of Variance (ANOVA). Comparisons of pH and titratable acidity means were performed by Tukey test at a 5% significance level (p<0.05). Results: the pH values that ranged from 2.4 (freezing hug) to 3.5 (witch's slime) differed significantly from the control (mineral water/ pH=6.2). Titratable acidity values ranged from 628µL of 0.1 M NaOH (blood) to 10700µL of 0.1 M NaOH (freezing hug). The freezing hug flavor chewing gum had the lowest pH and the highest titratable acidity differing significantly from the other flavors. Conclusions: the evaluated chewing gums are acidic, but differ in their erosive potential. Their abusive consumption may constitute a risk factor for dental erosion.(AU)

Análise físico-química de balas duras e mastigáveis e o seu efeito desmineralizante em esmalte bovino / Physico-chemical analysis of hard and soft candies and their demineralizing effect in bovine enamel

Objetivo: avaliar o potencial cariogênico de balas duras e mastigáveis e seu potencial desmineralizante em esmalte bovino. Métodos: foram selecionadas 30 balas de diferentes marcas, divididas em balas duras (n=11), Tic Tac®, Halls® e IceKiss®, e balas mastigáveis (n=19), Lílith®, Azedinha®, Mentos Rainbow® e Dori Gomets®. As balas foram dissolvidas em água destilada (1:10) e foram avaliados pH, acidez titulável (ATT) e presença de sólidos solúveis totais (SST/°Brix). Na ciclagem erosiva, 40 espécimes de esmalte bovino foram divididos em quatro grupos (n=10): GCN ­ saliva artificial; GCP ­ ácido clorídrico; GT1 ­ solução da bala Lílith® maçã verde; GT2 ­ solução da bala IceKiss® extraforte. O desafio erosivo foi realizado por 2 minutos, 4x/dia, segui-do de 2 horas de imersão em saliva artificial durante cinco dias. Resultados: os valores de pH para as balas duras e mastigáveis variaram de 2,88 a 5,53 e de 2,73 a 4,16, respectivamente. ATT em pH 5,5 variou de 0,07 mL a 39,40 mL de NaOH 0,1 N, para as balas duras, e de 1,53 mL a 35,83 mL, para balas mastigáveis. ATT em pH 7,0 variou de 0,2 mL a 49,13 mL de NaOH, para balas duras, e de 2,37 mL a 49,97 mL, para as mastigáveis. O conteúdo de SST de todas as balas duras foi superior a 8,5°Brix, já entre as mastigáveis variou de 5,3 a 8,83°Brix. O GCP apresentou maior desmineralização que GCN e GT2 (p<0,05). Conclusão: a maioria das balas duras e mastigáveis dissolvidas em água destilada mostraram-se potencialmente erosivas e cariogênicas.(AU)

Objective: evaluate the cariogenic potential of hard and soft candies and their demineralizing potential in bovine enamel. Methods: 30 candies of different brands were selected, divided into hard candies (n=11): Tic Tac®, Halls® and IceKiss® and soft candies (n=19): Lílith®, Azedinha®, Mentos Rainbow® and Dori Gomets®. The candies were dissolved in distilled water (1:10) and pH, titratable acidity (TT) and presence of total soluble solids (SST/°Brix) were evaluated. In erosive cycling, 40 specimens of bovine enamel were divided into four groups (n=10): GCN - artificial saliva; GCP - hydrochloric acid; GT1 - Lilith® apple green candy solution; GT2 - IceKiss® Extra Strong candy Solution. The erosive challenge was performed for 2 minutes, 4X/day, followed by 2 hours of immersion in artificial saliva for five days. Results: pH values for hard and soft candies ranged from 2.88 to 5.53 and 2.73 to 4, respectively. ATT at pH 5.5 varied from 0.07 mL to 39.40 mL of 0.1 N NaOH for hard candies and 1.53 mL to 35.83 mL for soft candies. ATT at pH 7,0 varied from 0.2 mL to 49.13 mL of 0.1 N NaOH for hard candies and from 2.37 mL to 49.97 mL for soft candies. The content of SST of all hard candies was higher than 8.5 °Brix and for soft candies, varied between 5.3 to 8.83 °Brix. The GCP group showed greater demineralization than GCN and GT2 (p<0.05). Conclusion: most hard and soft candies dissolved in distilled water were potentially erosive and cariogenic.(AU)

Surface morphologic evaluation of orthodontic bonding systems under conditions of cariogenic challenge

Abstract: Orthodontic bonding systems are submitted to demineralization and remineralization dynamics that might compromise their surface smoothness, and favor biofilm aggregation and caries development. The aim of the present study was to evaluate the effects of a cariogenic challenge model (in vitro pH-cycling model) on the surface roughness and topography of 3 bonding materials: Transbond™ XT (XT), Transbond™ Plus Color Change (PLUS) and Fuji Ortho™ LC (FUJI), by means of Atomic Force Microscopy (AFM). Six specimens with standardized dimensions and surface smoothness were fabricated per group, and the materials were manipulated in accordance with the manufacturers' instructions. No polishing was necessary. AFM tests were performed before and after pH-cycling, taking 3 readouts per specimen. The roughness results (Ra) were obtained at nanometric levels (nm) and surface records were acquired in two- and three-dimensional images of height and lock-in phase of the material components. The surfaces of all groups analyzed in the study were morphologically altered, presenting images suggestive of matrix degradation and loss of matrix-load integrity. FUJI presented the greatest increase in surface roughness, followed by XT and PLUS, respectively (p≤0.001). Nevertheless, the roughness values found did not present sufficient degradation to harbor bacteria. The surface roughness of all tested materials was increased by pH-cycling. The use of materials capable of resisting degradation in the oral environment is recommended, in order to conserve their integrity and of the surrounding tissues.

The role of human milk and sucrose on cariogenicity of microcosm biofilms

Abstract This study investigated the effect of human milk, alone and associated with sucrose, in the cariogenicity of biofilms in a microcosm biofilm model and compared with the cariogenicity of sucrose and bovine milk. Microcosm biofilms were grown in enamel discs in 24-well plates. Six growth conditions were studied: DMM (chemically defined artificial saliva - negative control), DMM with 1% of sucrose (DMM+s) (positive control), human milk with DMM, human milk with DMM+s, bovine milk with DMM, and bovine milk with DMM+s. After 5 days, the outcome variables surface hardness change (%SHC), microbiological composition of biofilms, and pH of supernatant were analyzed. All groups had significantly lower hardness loss compared to the DMM group with 1% of sucrose. Human and bovine milk associated with sucrose showed higher hardness loss. The supernatant pH values after 6 hours of different treatments were similar for the groups sucrose and human milk associated with sucrose (p>0.05). After 18 hours at rest in pure DMM, an increase in the pH of the supernatant was observed. Higher values of total microorganisms count were found for sucrose and bovine milk groups compared to the group supplemented only by DMM. Bovine milk group showed greater amount of total aciduric microorganisms in comparison to human milk group. Within the limits of this study, it can be infered that both human and cow milks have some cariogenic potential, although differing from sucrose in terms of mineral loss.

Enamel and dentine demineralization by a combination of starch and sucrose in a biofilm - caries model

Abstract Sucrose is the most cariogenic dietary carbohydrate and starch is considered non-cariogenic for enamel and moderately cariogenic for dentine. However, the cariogenicity of the combination of starch and sucrose remains unclear. The aim of this study was to evaluate the effect of this combination on Streptococcus mutans biofilm composition and enamel and dentine demineralization. Biofilms of S. mutans UA159 were grown on saliva-coated enamel and dentine slabs in culture medium containing 10% saliva. They were exposed (8 times/day) to one of the following treatments: 0.9% NaCl (negative control), 1% starch, 10% sucrose, or 1% starch and 10% sucrose (starch + sucrose). To simulate the effect of human salivary amylase on the starch metabolization, the biofilms were pretreated with saliva before each treatment and saliva was also added to the culture medium. Acidogenicity of the biofilm was estimated by evaluating (2 times/day) the culture medium pH. After 4 (dentine) or 5 (enamel) days of growth, biofilms (n = 9) were individually collected, and the biomass, viable microorganism count, and polysaccharide content were quantified. Dentine and enamel demineralization was assessed by determining the percentage of surface hardness loss. Biofilms exposed to starch + sucrose were more acidogenic and caused higher demineralization (p < 0.0001) on either enamel or dentine than those exposed to each carbohydrate alone. The findings suggest that starch increases the cariogenic potential of sucrose.

Calcium binding to S. mutans grown in the presence or absence of sucrose

Sucrose is the most cariogenic dietary carbohydrate because it is a substrate for insoluble extracellular polysaccharide (IEPS) production in dental biofilms, which can proportionally decrease bacterial density and, consequently, the number of biofilm calcium (Ca) binding sites. Ca bound to bacterial cell walls can be released into the biofilm fluid during a cariogenic challenge, reducing the driving force for mineral dissolution provoked by the pH drop. Thus, we investigated the effect of an IEPS-rich extracellular matrix on bacterial Ca binding after treatment with Ca solutions. Streptococcus mutans Ingbritt 1600 was cultivated in culture broths supplemented with 1.0% sucrose or 0.5% glucose + 0.5% fructose. The IEPS concentration in bacterial pellets was determined after alkaline extraction. Bacterial pellets were treated with 1 mM or 10 mM Ca++ solutions at 37ºC for 10 to 60 min. Ca binding to bacterial pellets, determined after acid extraction using the Arsenazo III reagent, was fast and concentration dependent. Although the IEPS concentration was approximately ten times higher in bacterial pellets cultivated in sucrose as compared to its monossaccharides, bound Ca concentration after Ca treatment was similar in both conditions. These results suggest that IEPS may not influence the amount of Ca bound to reservoirs of dental biofilms.

Estimación del riesgo a caries dental en escolares a través de evaluaciones clínicas, microbiológicas y radiológicas / Dental caries risk estimation in schoolchildren, trougth clinical, microbiological and radiological evaluation

The purpose of this epidemiological study was to find correlation among dental caries and S. mutans in schoolchildren from a Protection Center. Quantitative and semiquantitative methods were employed to determine salivary concentration of mutans streptococci. The results showed that 44 percent of children had 1-3 dental caries, while 23 percent had 4-7. A direct relationship was found with the concentration of mutans streptococci in saliva. Both methods employed showed that the caries risk level, can be stabilized approximately in 5 x 105 UFCf S. mutans/mL saliva. Biochemical and serological characterisation of the isolated streptococci mutans group revealed that 95 percent was of biotype I, serotype c (c, e, f) belonged to S. mutans specie, and of 5 percent was S. sobrinus biotype IV, serotype (d, g, h). A direct correlation between decalcified areas and the quantity of salivary S. mutans was also found. Based in these results, a prediction about people in risk of develop dental caries, can be made, and so adequate prevention programs, can be established