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)

Hipomineralización incisivo molar y factores etiológicos ambientales. Revisión de la literatura / Molar incisor hypomineralization and etiological environmental factors. Review of the literature

La etiología de la hipomineralización incisivo-molar (HIM) aún no está totalmente definida, por lo que el objetivo del presente artículo fue hacer una revisión de la literatura de los posibles factores etiológicos asociados. Se realizó una búsqueda inicial en las bases de datos Elsevier, EBSCO, PubMed y Medline usando las siguientes palabras clave: molar incisor hypomineralisation, hypoplasia, dental enamel defects epidemiology, etiology. Se incluyeron artículos en inglés y español, estudios epidemiológicos de casos y controles de HIM, descripción del método de diagnóstico y registro, y descripción del factor asociado, publicados entre 1987 y 2018. Tomando en consideración 40 artículos que cumplían con los criterios de búsqueda. Se dividieron los factores etiológicos encontrados en tres etapas: prenatal, perinatal y posnatal. La causa exacta aún no está del todo definida, pero con base en los estudios tenemos indicios que nos podrían ayudar a prevenir este tipo de defectos. Sin embargo, son necesarios más estudios longitudinales para poder determinar la etiología exacta de esta alteración en la formación dental, mientras tanto los médicos pediatras y odontopediatras deben estar conscientes que el manejo temprano y adecuado de estas del HIM es importante. (AU)

The etiology of molar incisor hypomineralization (MIH) is not yet fully defined, therefore the objective of this article was to review the literature on the possible associated etiological factors. An initial search was performed in the Elsevier, EBSCO, PubMed and Medline databases using the following keywords: molar incisor hypomineralization, hypoplasia, dental enamel defects epidemiology, and etiology. Articles in English and Spanish were included as well as epidemiological studies of cases and controls of MIH, descriptions of the method of diagnosis and registration, and descriptions of associated factors published between 1987 and 2018. Forty articles met the search criteria. The etiological factors found were divided into three stages: prenatal, perinatal and postnatal. While the cause of MIH has yet to be fully defined, the studies available describe indications to help prevent this type of defects. Nonetheless, more longitudinal studies are necessary to determine the exact etiology of this alteration, and pediatricians and pediatric dentists should take into account the importance of early, adequate management of MIH. (AU)

Effect of fluoride application during radiotherapy on enamel demineralization

Abstract Radiation-related caries are one the most undesired reactions manifested during or after head and neck radiotherapy. Fluoride application is an important strategy to reduce demineralization and enhance remineralizaton. Objective: To evaluate the effect of the topical application of fluoride during irradiation on dental enamel demineralization. Material and Methods: Thirty molars were randomly divided into three groups: Non-irradiated (NI), Irradiated (I), Irradiated with fluoride (IF). Each group was subdivided according to the presence or absence of pH-cycling (n=5). In the irradiated groups, the teeth received 70 Gy. The enamel's chemical composition was measured using Fourier Transform Infrared Spectrometry (organic matrix/mineral ratio - M/M and relative carbonate content - RCC). Vickers microhardness (VHN) and elastic modulus (E) were evaluated at three depths (surface, middle and deep enamel). Scanning electron microscopy (SEM) was used to assess the enamel's morphology. Results: The FTIR analysis (M/M and RCC) showed significant differences for irradiation, pH-cycling and the interaction between factors (p<0.001). Without pH-cycling, IF had the lowest organic matrix/mineral ratio and relative carbonate content. With pH-cycling, the organic matrix/mineral ratio increased and the relative carbonate content decreased, except for IF. VHN was influenced only by pH-cycling (p<0.001), which generated higher VHN values. ANOVA detected significant differences in E for irradiation (p<0.001), pH-cycling (p<0.001) and for the interaction between irradiation and pH-cycling (p<0.001). Increased E was found for group I without pH-cycling. With pH-cycling, groups I and IF were similar, and showed higher values than NI. The SEM images showed no morphological changes without pH-cycling. With pH-cycling, fluoride helped to maintain the outer enamel's morphology. Conclusions: Fluoride reduced mineral loss and maintained the outer morphology of irradiated and cycled enamel. However, it was not as effective in preserving the mechanical properties of enamel. Radiotherapy altered the enamel's elastic modulus and its chemical composition.

Erosive potential of sports beverages on human enamel "in vitro" / Potencial erosivo de bebidas esportivas no esmalte humano "in vitro" / Potencial erosivo de bebidas deportivas en el esmalte humano "in vitro"

INTRODUCTION: The low pH of sports drinks may cause tooth enamel demineralization. Objective: To measure Vickers hardness of human enamel exposed to sports drinks. METHODS: Human molars were used to collect the enamel samples. Each sample had a test surface (exposed to the drinks) and a control surface (unexposed). The samples were exposed to isotonic drinks Gatorade and Powerade, and to maltodextrin drinks Malto Advanced and Malto Active, for 10 minutes every 12 hours over 30 days. The Vickers microhardness test was conducted with three indentations on each surface. The mean of the indentations within each group was considered in the statistical analysis. Sports drinks variables were analyzed with ANOVA/Tukey (p≤0.01). The independent t-test was used in the comparison between the control and test surfaces of each drink (p ≤ 0.05). RESULTS: Enamel exposure to Gatorade (p = 0.000) Malto Advanced (p = 0.000) and Malto Active (p = 0.000) was seen to significantly reduce microhardness, while the isotonic drink Powerade had no significant effect on enamel (p = 0.248). CONCLUSION: It was concluded that with the exception of the isotonic drink Powerade, all the sports drinks tested caused a reduction in the microhardness of human enamel. Evidence Level III; Therapeutic studies - Investigating the Results of Treatment.

INTRODUÇÃO: O baixo pH de bebidas esportivas pode promover perda mineral do esmalte dental. OBJETIVO: Avaliar a microdureza Vickers do esmalte humano exposto a bebidas esportivas. MÉTODOS: Dentes molares humanos foram usados para coletar as amostras de esmalte. Cada amostra apresentou uma superfície de teste (exposta às bebidas) e uma superfície de controle (não exposta). As amostras foram expostas aos isotônicos Gatorade e Powerade e às maltodextrinas Advanced Series e Malto Active durante 10 minutos de 12/12 horas, durante 30 dias. O teste de microdureza Vickers foi realizado com três indentações em cada superfície. Na análise estatística, foi considerada a média das indentações dentro de cada grupo. As variáveis bebidas esportivas foram avaliadas com ANOVA/Tukey (p ≤ 0,01). Na comparação entre a superfície controle e teste de cada bebida foi utilizado o Teste t para amostras independentes (p ≤ 0,05). RESULTADO: Observou-se que a exposição do esmalte a Gatorade (p = 0,000), Malto Advanced (p = 0,000) e Malto Active (p = 0,000) reduz significativamente a microdureza, enquanto que o isotônico Powerade não produziu efeito significativo sobre o esmalte (p = 0,248). CONCLUSÃO: Concluiu-se que com exceção do isotônico Powerade, todas as bebidas esportivas testadas provocaram redução na microdureza do esmalte dental humano. Nível de Evidência III; Estudos terapêuticos ­ investiga o resultado de um tratamento.

INTRODUCCIÓN: El bajo pH de bebidas deportivas puede favorecer la pérdida mineral del esmalte dental. OBJETIVO: Evaluar el esmalte dureza Vickers humano expuesto a las bebidas deportivas. MÉTODOS: Se utilizaron los dientes molares para la toma de las muestras de esmalte. Cada muestra tenía una superficie de prueba (expuestos a las bebidas) y una superficie de control (no ex-puesta). Las muestras fueron expuestas en isotónica Gatorade y Powerade, y maltodextrinas, y la serie Advanced activo Malto durante 10 minutos 12/12 horas durante 30 días. La prueba de dureza Vickers se realizó con tres muescas en cada superficie. El análisis estadístico fue la media de las muescas dentro de cada grupo. variables de bebidas deportivas se analizaron con ANOVA / Tukey (p≤0,01). La comparación entre la superficie de control y prueba de cada bebida se utilizó la prueba t para muestras independientes (p ≤ 0,05). RESULTADOS: Se observó que la exposición del esmalte Gatorade (p = 0,000) Malto avanzada (p = 0,000) y Malto activo (p = 0,000) reduce significativamente la dureza, mientras que Powerade isotónica ningún efecto significativo sobre el esmalte (p = 0,248). CONCLUSIÓN: Se concluye que con la excepción de Powerade isotónica, todas las bebidas deportivas probados causó una reducción en la dureza del esmalte humano. Nivel de Evidencia; Estudios terapéuticos - Investigación de los resultados del tratamento.

Molar-Incisor Hypomineralization and Associated Factors: A Case- Control Study

Objective: To evaluate systemic factors those are related to molar incisor hypomineralization (MIH), its association with dental caries, and the impact on oral health-related quality of life (OHRQoL) in Brazilian children. Material and Methods: This case-control study was conducted at the Pediatric Dentistry Clinic, Federal University of Parana, Brazil. Patients with MIH who were assisted from 2014 to 2015 were included in the study, for a total of 31 children, 6-13 years of age. The control group consisted of 62 children who were matched by sex and age. European Academy of Pediatric Dentistry criteria were used for MIH diagnosis. The children's mothers answered a questionnaire regarding the children's history of health intercurrences in the pre-, peri-, and postnatal periods. The Decayed, Missing, or Filled Teeth indices for permanent and primary teeth (dmft index and DMFT index, respectively) were used for dental caries examination by two calibrated examiners. Child Perceptions Questionnaires for 8- to 10-year-old children and 11- to 14-year-old children (CPQ8-10 and CPQ11-14) were used to assess OHRQoL. Results: Prematurity and prolonged delivery were significantly associated with the occurrence of MIH. In the postnatal period, recurrent fevers in the first 3 years of life were associated with MIH. Of the 339 incisors and first permanent molars that were examined, 178 presented MIH, of which 116 (65%) were demarcated opacities. A significant difference was found in the mean DMFT index between groups. No impact of MIH on OHRQoL was observed. Conclusion: The present results suggest higher intercurrences during the perinatal period and a higher incidence of caries among children with MIH.

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.

Odontopediatría y enfermedad celíaca: diagnóstico y tratmaiento de las lesiones bucales / Pediatric dentistry and celiac disease: diagnosis and treatment of the oral lesions

La enfermedad celíaca es una alteración de base inmunológica que puede presentarse en cualquier etapa de la vida. La causa es la intolerancia al gluten en aquellas personas predispuestas genéticamente. El diagnóstico precoz en niños permite adherir auna dieta libre de gluten y evitar consecuencias vinculadas con la enfermedad. El objetivo de este trabajo es orientar sobre las lesiones en tejidos blandos y duros de la cavidad bucal o retardo en la cronología de la erupción, que podrían asociarse a enfermedad celíaca (EC) y realizar la derivación oportuna al médico pediatra...

Prevalence and severity of molar incisor hypomineralization in students of Belém, Brazil

To measure the prevalence of Molar Incisor Hypomineralization (MIH), its severity and association with dental caries among public school children from Belém/PA, Brazil.Material and Methods:This is a cross-sectional study conducted with children enrolled in three public schools of Belém, which were selected by simple random sampling. MIH diagnosis was carried out according tocriteria of the European Academy of Pediatric Dentistry.Results:Among the 260 students that met the inclusion criteria, 56.92% were male and 43.07% female. The average age was 10.22 years. Of these, 8.84% (n = 23) had MIH, but there was no statistically significant difference in this prevalence between sexes (p = 0.6244). The most affected teeth were the upper first permanent molars, followed by lower first permanent molars and upper permanent central incisors. About 43.48% of students had at least one tooth with severe defect in enamel and 30.43% of students with MIH presented dental caries in the affected teeth. Conclusion:Severe MIH was not the most prevalent among schoolchildren, but the relationship with dental caries found demonstrates the importance of knowledge about diagnosis and treatment of enamel defects, which should be part of promotion and prevention actions in oral health due to its epidemiological impact in the demographic change of dental caries...

Molar-incisor hypomineralization in schoolchildren of Manaus, Brazil

To analyze the prevalence and severity of Molar Incisor Hypomineralization (MIH) and its relationship with dental caries in public school children in Manaus/AM.Material and Methods:Overall, 2,062 primary school children aged 6-10 years were examined to obtain MIH, DMFT, dmft and DDE indexes. The participation of five schools in each district of the city of Manaus was randomly determined, totaling 40 schools, and in each of them, two classes of each grade of elementary school in two shifts were selected, totaling 10 classes. Clinical examinations were conducted by two previously calibrated examiners in school environment under natural lighting. Data collected were submitted to descriptive statistical analysis by Chi-square, Fisher's Exact and Mann-Whitney tests at 5% significance level. Results:The prevalence of MIH in Manaus was 9.12% and no significant association with gender and age of schoolchildren was found. The mandibular arch was the most affected, with greaternumber of teeth being affected on the left side. The most frequently affected teeth were the mandibular permanent first molars, followed by maxillary counterparts and maxillary/mandibular central incisors. The most frequent diagnosis was mild MIH. The DMFT of children with MIH was 1.58 and dmft was 2.47, higher than those of the unaffected group. A correlation was found between DDE and MIH. Conclusion:Earlydiagnosis of MIH is imperative, since children affected show high risk for the development of dental caries...

Influence of deciduous molar hypomineralization on the development of molar-incisor hypomineralizarion

Defects similar to Molar-Incisor Hypomineralization (MIH) in second primary molars can be found in the literature, being recently named Deciduous Molar Hypomineralization (DMH). Researchers have stated that the presence of DMH in primary dentition represents a risk for MIH in permanent teeth. The explanation for this association is probably related to the etiological factors. AIM: To investigate prospectively the association between DMH and MIH and the etiologic factors involved in both defects. METHODS: One hundred and thirty four children aged 4 to 6 years from Botelhos, MG, Brazil, were evaluated six-monthly until they completed the eruption of the first permanent molars. A structured questionnaire was developed with questions about the child's health up to the first year of life and the mother's health during pregnancy. RESULTS: It could be noted that, although most children with DMH in the primary dentition had higher incidence of MIH in permanent dentition, this difference was not statistically significant. CONCLUSIONS: None of the possible etiologic factors had associations with the studied enamel defects, even among children who presented two types of enamel defects in the mixed dentition. However, further studies with larger samples should be conducted in order to confirm or refute the findings of the present study.

Influence of photo-activation source on enamel demineralization around restorative materials

This study evaluated the effects of the photoactivation source and restorative material on the development of caries-like lesions on human enamel after an in vitro pH challenge. Enamel cavities were prepared in 36 blocks, which were assigned to two groups according to the restorative material: resin-modified glass ionomer (RMGI) and composite resin (CR). Samples were exposed to quartz-tungsten-halogen lamp, argon-ion laser, or light-emitting diode (n = 6). The Knoop microhardness (KHN) values of the top surface of all materials were evaluated. Restored enamel blocks were thermocycled and subjected to 10 demineralization-remineralization cycles at 37°C. KHN analysis of the superficial enamel was performed by four indentations located 100 mm from the restoration margin. The material KHN was not affected by the photoactivation source. No significant difference in KHN was noted between CR and RMGI. The enamel surface around RMGI exhibited a higher KHN (272.8 KHN) than the enamel around CR (93.3 KHN), regardless of the photoactivation source. Enamel demineralization around the dental restoration was not influenced by the photoactivation source. Less enamel demineralization was observed around the RMGI than around the CR restoration.

Molar incisor hypomineralization: three case reports and discussion of etiology, diagnosis, and management strategies / Hipomineralização de molar e incisivo: três relatos de caso e discussão sobre etiologia, diagnóstico e estratégias de tratamento

O objetivo deste artigo, que inclui três relatos de caso, é discutir brevemente a etiologia, o diagnóstico e as estratégias de tratamento de três pacientes com hipomineralização de molares e incisivos. Nos três casos apresentados, a etiologia estava relacionada a fatores sistêmicos que ocorreram durante o primeiro ano de vida, especialmente deficiência do sistema respiratório e episódios de febre alta. O diagnóstico foi realizado com base em exame clínico de características específicas como mudanças na cor e opacidade e perda de estrutura dentária. Decisões de tratamento foram tomadas de acordo com a severidade da hipomineralização em cada paciente, variando desde conduta expectante/acompanhamento até a restauração estética de incisivos permanentes. Nossos relatam indicam que a hipomineralização de molares e incisivos pode ocorrer, predominantemente, em crianças com história de deficiência respiratória e episódios de febre alta durante o primeiro ano de vida. O diagnóstico inicial normalmente é determinado pelo exame visual, e a decisão de tratamento dependerá da severidade da hipomineralização.

The aim of this article including three case reports is to briefly discuss the etiology, diagnosis, and treatment of patients with molar incisor hypomineralization. In all three cases presented, the etiology was related to systemic factors that occurred in the first year of life, especially respiratory deficiency and episodes of high fever. Diagnosis was based on clinical examination of specific characteristics such as changes in color and opacity and loss of tooth structure. Treatment decisions were made according to severity of hypomineralization in each patient, ranging from expectant management/follow-up to esthetic restoration of permanent incisors. Our reports suggest that molar incisor hypomineralization occur predominantly in children with a history of respiratory deficiency and episodes of high fever in the first year of life. Early diagnosis is usually determined by visual examination and treatment decision is dependent on condition severity.

Etiología de las opacidades severas del esmalte: una evaluación basada en un estudio prospectivo médico y social en 17000 niños / Aetiology of severe demarcated enamel opacities: an evaluation based on prospective medical and social data from 17000 children

Durante los años 70s, los odontólogos describieron una prevalencia creciente de un nuevo tipo de alteración en el esmalte. Este era muy específico, con áreas de demarcado esmalte hipomineralizado y se encontraba en su mayoría en los primeros molares permanentes y en los incisivos. Diferentes estudios trataron de relelar la etiología de estas alteraciones, pero hasta ahora no se han encontrado factores claramente relacionados. El propósito del presente trabajo fue evaluar los factores etiológicos de las opacidades demarcadamente severas (OSD) en los primeros molares permanentes en una gran cohorte de niños incluidos en el proyecto "Todos los niños del sudeste de Suecia" (ABIS). Se llevó a cabo un estudio prospectivo de los niños de 5 condados suecos nacidos entre el 1º de octubre de 1997 y el 1 de octubre de 1999, un total de 17000 niños que fueron seguidos desde su nacimiento y fueron registrados un gran número de factores sobre nutrición, enfermedades, medicación, infecciones, situación social, etc. Con la ayuda de 89 clínicas del Servicio Dental Público, en la misma área, se realizaron exámenes preliminares de los niños nacidos entre octubre 1º de 1997 y octubre 1º de 1999. Se analizaron 595 niños con opacidades severamente marcadas (OSD) en los primeros molares. Estos niños, y un grupo control de 1200 niños seleccionados al azar fueron luego invitados para ser examinados por odontopediatras. En estos exámenes se identificaron 224 casos severos, como así también 253 niños sin ninguna alteración en el esmalte. Fueron analizados estos dos grupos. No hubo ninguna correlación entre OSD y las variables del banco de datos del ABIS. Los análisis muestran que no existe asociación entre OSD y datos pre, peri y neonatales. Sin embargo, hemos encontrado una asociación positiva entre OSD y el alimento a pecho por más de 6 meses.

Avaliação microestrutural do esmalte bovino exposto a bebidas lácteas fermentadas e propriedades físico químicas / Microstructural evaluation of bovine enamel exposed to fermented dairy beverages and analysis of their physical-chemical properties

Objetivo: Analisar o padrão de desmineralização do esmalte bovino submetido à ação de bebidas lácteas fermentadas frente a variações de tempo e avaliar as propriedades físico-químicas destes componentes da dieta líquida. Método: Analisaram-se seis marcas de bebidas lácteas, utilizando-se refrigerante a base de cola e água destilada como controle positivo (CP) e negativo (CN), respectivamente. Avaliou-se o pH por meio de pHmêtro digital enquanto a concentração de sólidos solúveis totais (°Brix) foi mensurada por um refratômetro específico de campo. Por meio de um viscosímetro capilar aferiu-se a viscosidade cinemática. Analisou-se a ação das bebidas sobre o esmalte em Microscopia Eletrônica de Varredura (MEV) após exposição às soluções nos intervalos de tempo: 5, 15 e 30 minutos, sendo as alterações microestruturais classificadas em escores, de acordo com o grau de desmineralização promovido na estrutura dentária. Resultados: Os valores de pH variaram de 2,59 (CP) a 6,24 (CN), estando as demais bebidas lácteas fermentadas abaixo do pH 3,92. Os valores de °Brix oscilaram de 0° a 19° Brix e a viscosidade variou de 2,41 mm²/s a 7,26 mm²/s. Alterações sugestivas de erosão foram evidentes nos espécimes submetidos ao CP e ao produto de menor pH. A maioria das bebidas registrou dissoluções iniciais a partir de 15 minutos, correspondendo a alterações Grau 1 (leve alteração microestrutural). Conclusão: As bebidas lácteas revelaram-se potencialmente erosivas e cariogênicas, apresentando valores de pH críticos para dissolução do esmalte, bem como presença de sólidos solúveis totais e expressiva variação de viscosidade. A análise morfológica pela MEV da superfície dentária revelou alterações microestruturais de leve a acentuada, de acordo com o tempo de exposição às bebidas.

Objective: The aim of this study was to analyze the pattern of demineralization of bovine enamel subjected to the action of fermented dairy beverages after different times and to evaluate their physical-chemical properties. Method: Six brands of dairy beverages were analyzed, having cola-type soft drink and distilled water as positive (PC) and negative (NC) controls, respectively. The pH was evaluated using a digital pH-meter and the soluble solids content (°Brix) was measured using a specific refractometer. A capillary viscometer measured the kinematic viscosity. The action of the beverages on enamel was analyzed by scanning electron microscopy (SEM) after exposure to solutions at the following time intervals: 5, 15 and 30 minutes. The microstructural alterations were scored according to the degree of demineralization observed on tooth structure. Results: The pH values ranged from 2.59 (PC) to 6.24 (NC), while the pH of the fermented dairy beverages was below 3.92. The soluble solids content values ranged from 0° to 19° Brix and viscosity ranged from 2.41 to 7.26 mm²/s. Changes suggestive of erosion were evident in the specimens submitted to the PC and to the beverage with the lowest pH. Most beverages promoted initial enamel dissolution after 15 minutes, corresponding to grade 1 alterations (mild microstructural alteration). Conclusion: The fermented dairy beverages were found to be potentially erosive and cariogenic, presenting pH values compatible with the critical value for enamel dissolution as well as total soluble solids and significant viscosity variation. Morphological analysis of tooth surface by SEM revealed microstructural changes from mild to severe, according to the exposure time to the beverages.

Evaluation of demineralization adjacent to orthodontic bracket and bond strength using fluoride-releasing and conventional bonding agents.

Background and Objectives: One of the most difficult problems encountered in orthodontic treatment with fixed appliance is the control of enamel demineralization around the brackets. Fluoride-releasing bonding adhesives were introduced to aid in the prevention of demineralization adjacent to orthodontic brackets. Hence, an in vitro study was conducted to evaluate and compare demineralization adjacent to the orthodontic bracket and the bond strength using fluoride-releasing adhesive and conventional adhesive. Materials and Methods: One hundred and twenty healthy extracted premolars were selected for the study and were divided into two groups, each group consisting of 60 teeth. Both groups were further divided into three subgroups consisting of 20 samples each. Samples of subgroups A and B were bonded with two prototypes of fluoride-releasing adhesives (i.e. Rely-a-bond and Tru-bond). Samples of subgroup C (ortho-one) were bonded with conventional non-fluoride-releasing adhesive. Group I samples were subjected to demineralization in an acidic medium (methyl cellulose buffered with acetic acid at a pH of 4.5) for 4 weeks, which were later observed under a stereomicroscope. Group II samples were tested for shear bond strength using the Instron Universal testing machine. Results: Both fluoride-releasing adhesives showed statistically significant lower enamel demineralization around the bracket when compared with the conventional adhesive. There was no statistically significant difference on comparing the demineralization between the two prototypes of fluoride-releasing adhesive. Evaluation of shear bond strength revealed that there was no significant difference between the subgroups. Conclusion: Fluoride-releasing adhesives might aid in the prevention of demineralization adjacent to the orthodontic bracket with acceptable bond strength.

Desmineralização dentária de pacientes respiradores orais submetidos à expansão maxilar / Demineralization of teeth in mouth-breathing patients undergoing maxillary expansion

A respiração oral pode causar deformações na arcada dentária e representar risco a cáries e doenças periodontais, podendo ser agravado pela utilização de aparelhos fixos. OBJETIVO: Avaliar o grau de mineralização do esmalte dentário e a microbiota cariogênica bucal de respiradores orais que utilizaram disjuntores maxilares. MATERIAL E MÉTODO: Estudo prospectivo com 20 pacientes respiradores orais com atresia maxilar, idades entre 9 e 13 anos. A mineralização do esmalte dentário foi medida pela técnica de fluorescência, antes da instalação do disjuntor maxilar e após sua remoção. A microbiota cariogênica foi avaliada pelo No Caries®. Na análise estatística utilizamos o teste "t" (p<0,05), e a microbiota oral analisada por incidência. RESULTADOS: Houve diferença estatisticamente significante no grau de mineralização do esmalte dentário após a disjunção maxilar, com valor médio de 3,08. O teste colorimétrico demonstrou que 45 por cento diminuiu e 15 por cento aumentou o potencial à cárie dentária, sendo que 40 por cento permaneceu inalterado após o uso do disjuntor maxilar. CONCLUSÃO: Houve diferença estatisticamente significante no grau de mineralização do esmalte dentário nos pacientes respiradores orais após a utilização de disjuntor, porém dentro da faixa de normalidade clínica, e um número pequeno de pacientes aumentou o potencial cariogênico durante o tratamento ortodôntico.

Mouth breathing may cause deformities on the dental arch and be a risk factor for caries and periodontal disease; fixed orthodontic appliances compound the problem. AIM: to evaluate mineralization of tooth enamel and the oral cariogenic microbiota of mouth breathers that are using maxillary expanders. MATERIAL AND METHOD: a prospective study of 20 mouth-breathing patients with maxillary atresia, aged from 09 to 13 years. Enamel mineralization was measured using a fluorescence technique, before installing the expander and after its removal. The cariogenic microbiota was evaluated by the No Caries®. The t test (p<0.05) was applied for the statistical analysis, and the oral microbiota was analyzed by incidence. RESULTS: there was a statistically significant difference in the enamel mineralization level after maxillary expansion; the mean value was 3.08. The colorimetric test showed that the caries development potential was reduced in 45 percent, increased in 15 percent, and unaltered in 40 percent after maxillary expander use. CONCLUSION: there was a statistically significant difference in enamel mineralization after maxillary expansion; this difference was within the clinically normal range; the cariogenic potential increased in a small number of patients during orthodontic treatment.

Effect of different frequencies of fluoride dentifrice and mouthrinse administration: an in situ study

The effect of a combination of topical fluoridation methods for inhibition of enamel demineralization in the face of a cariogenic challenge has not been clearly established. This in situ crossover study aimed to assess whether the addition of daily use of fluoride mouthrinse (FR) to that of fluoride dentifrice (FD) is equivalent to increasing the frequency of FD application in terms of the effect on enamel demineralization and fluoride content. Over 3 phases of 14 days each, 12 volunteers wore appliances containing enamel blocks exposed to a 20 percent sucrose solution 8 times/day. During each phase the blocks underwent one of the following treatments: 2x/day FD, 2x/day FD + 1x/day FR, and 3x/day FD. The blocks were assessed for hardness and fluoride content. Three x/day FD did not differ from 2x/day + 1x/day FR, however it enhanced demineralization protection when compared to 2x/day FD. All treatments produced an increase in enamel fluoride content compared to no treatment (sound blocks) (p < 0.05), but the differences between them were not significant. The results of this study suggest that the daily use of fluoride mouthrinse combined with that of fluoride dentifrice has similar effects on enamel demineralization and fluoride content when compared to increasing the frequency of fluoride dentifrice use.

Refrescos ácidos: dissolução do esmalte / Acid fizzy drink: dissolution of enamel

Introdução: erosão é a perda superficial do esmalte causado por processos químicos que não envolvem bactérias, mas fatores extrínsecos como o alto consumo de bebidas que possuem pH muito baixo. Objetivo: avaliação da rugosidade superficial do esmalte de dentes bovinos após a ação de bebidas ácidas. Material e métodos: as amostras foram imersas nas seguintes soluções: GI limonada, GII refresco artificial em pó sabor limão e GIII refrigerante light a base de cola contendo limão, verificando a rugosidade superficial do esmalte após a imersão. Resultados: a média da rugosidade foi GI (0,0120), GII (0,3215), GIII (0,0275). Conclusão: todas as bebidas testadas interferiram na rugosidade do esmalte; o suco em pó light causou o maior dano ao esmalte; o tempo de exposição do esmalte as bebidas, aumentou os valores da rugosidade.

Introduction: erosion is the superficial loss of enamel caused by chemical process do not involve bacterias but extrinsic factors as the high consumption of low pH drinks. Aim: evaluate the enamel superficial roughness of the bovine teeth after the contact of acid solutions. Material and methods: lemonade (group 1), artificial juice in powder with lemon flavor (group 2), and a light soft drink made of cola and lemon (group 3), evaluate the enamel superficial roughness of the bovine after action of solutions. Results: the roughness average was: GI (0,0120), GII (0,3215), GIII(0,0275). Conclusion: the beverage’s effects and the time were statistically significant, GII showed the biggest superficial roughness when compared with GI and GIII.