Eroded enamel rehardening using two intraoral appliances designs in different times of salivary exposure.

BACKGROUND: The aim of this study was evaluated the eroded enamel rehardening potential using upper palatal and lower buccal removable appliances in different times of salivary exposure (30 min, 1h, 2h, 12h) after a single erosive challenge event. MATERIAL AND METHODS: After initial surface hardness evaluation, bovine enamel blocks were eroded in vitro (0.01 M hydrochloric acid, pH 2.3, 30 seconds), selected (n = 160) and randomly assigned to the two appliance designs and twenty volunteers. Four enamel blocks were inserted in each removable appliance. On the in situ phase, the volunteers were instructed to use the upper palatal and lower buccal appliances simultaneously for 12 nonconsecutive hours. After each predetermined period of time of salivary exposure, the enamel blocks were removed from the appliances for immediate evaluation of surface hardness, enabling percentage of surface hardness recovery calculation (%SHR). The data were analyzed using two-way ANOVA and Tukey's test (α=5%). RESULTS: The results showed no difference in the degree of enamel rehardening by the upper palatal or lower buccal appliances (p >0.0001). Regarding the time of use of the appliances, it was demonstrated that 30 minutes (upper = 21.12%, lower = 19.84%) and 1 hour (upper = 35.69%, lower = 30.50%) promoted lower hardness recovery than two hours (upper = 44.65%, lower 40.80%) of salivary exposure (p<0.0001). The use of 12 hours (upper = 49.33%, lower = 49.00%), including the sleeping time of the volunteers did not increase the %SHR. CONCLUSIONS: The location of the appliance does not influence the re-hardening ability of saliva and the use of intraoral appliances for 2 hours seems to be appropriate for partial rehardening of the softened enamel surface. Key words:Tooth erosion, in situ, saliva, tooth remineralization.

Oral health-related quality of life of children with oral clefts and their families.

Oral health problems can influence people's Quality of Life (QoL) because of pain, discomfort, limitations, and other esthetics problems, affecting their social life, feeding, daily activities, and the individual's well-being. To compare oral health-related quality of life (OHRQoL) of children with and without oral clefts and their families. 121 children aged from 2 to 6 years, from both sexes, enrolled in the treatment routine of the Pediatric Dentistry Clinics of a Dental School and a Hospital for Cleft Treatment were divided into two groups: Group 1 - children with cleft lip and palate; Group 2 - children without cleft lip and palate. The OHRQoL was assessed using the validated Portuguese version of the Early Childhood Oral Health Impact Scale (B-ECOHIS). The questionnaire was answered individually, only once, at a private place. Mann-Whitney U test was used to verify differences between groups. Spearman's Rho test was used to associate sex and age with quality of life. The level of significance was set at 5% (p<0.05). According to the parents' perception on the OHRQoL of children with and without cleft lip and palate, oral health of children with oral clefts (Group 1) had a statistically significant impact on OHRQoL. The correlation of sex with impact on OHRQoL did not show statistically significant differences. On the other hand, the higher the age the higher the impact on QoL. The group comparison revealed that the cleft lip and palate negatively impacted on OHRQoL of 2 to 6-year-old children and their parents.

Dental enamel defect diagnosis through different technology-based devices.

INTRODUCTION: Dental enamel defects (DEDs) are faulty or deficient enamel formations of primary and permanent teeth. Changes during tooth development result in hypoplasia (a quantitative defect) and/or hypomineralisation (a qualitative defect). OBJECTIVE: To compare technology-based diagnostic methods for detecting DEDs. MATERIAL AND METHODS: Two-hundred and nine dental surfaces of anterior permanent teeth were selected in patients, 6-11 years of age, with cleft lip with/without cleft palate. First, a conventional clinical examination was conducted according to the modified Developmental Defects of Enamel Index (DDE Index). Dental surfaces were evaluated using an operating microscope and a fluorescence-based device. Interexaminer reproducibility was determined using the kappa test. To compare groups, McNemar's test was used. Cramer's V test was used for comparing the distribution of index codes obtained after classification of all dental surfaces. RESULTS: Cramer's V test revealed statistically significant differences (P < .0001) in the distribution of index codes obtained using the different methods; the coefficients were 0.365 for conventional clinical examination versus fluorescence, 0.961 for conventional clinical examination versus operating microscope and 0.358 for operating microscope versus fluorescence. The sensitivity of the operating microscope and fluorescence method was statistically significant (P = .008 and P < .0001, respectively). Otherwise, the results did not show statistically significant differences in accuracy and specificity for either the operating microscope or the fluorescence methods. CONCLUSION: This study suggests that the operating microscope performed better than the fluorescence-based device and could be an auxiliary method for the detection of DEDs.

Oral health-related quality of life of children with oral clefts and their families

Abstract Oral health problems can influence people's Quality of Life (QoL) because of pain, discomfort, limitations, and other esthetics problems, affecting their social life, feeding, daily activities, and the individual's well-being. Objective: To compare oral health-related quality of life (OHRQoL) of children with and without oral clefts and their families. Materials and Methods: 121 children aged from 2 to 6 years, from both sexes, enrolled in the treatment routine of the Pediatric Dentistry Clinics of a Dental School and a Hospital for Cleft Treatment were divided into two groups: Group 1 - children with cleft lip and palate; Group 2 - children without cleft lip and palate. The OHRQoL was assessed using the validated Portuguese version of the Early Childhood Oral Health Impact Scale (B-ECOHIS). The questionnaire was answered individually, only once, at a private place. Mann-Whitney U test was used to verify differences between groups. Spearman's Rho test was used to associate sex and age with quality of life. The level of significance was set at 5% (p<0.05). Results: According to the parents' perception on the OHRQoL of children with and without cleft lip and palate, oral health of children with oral clefts (Group 1) had a statistically significant impact on OHRQoL. The correlation of sex with impact on OHRQoL did not show statistically significant differences. On the other hand, the higher the age the higher the impact on QoL. Conclusions: The group comparison revealed that the cleft lip and palate negatively impacted on OHRQoL of 2 to 6-year-old children and their parents.

Susceptibility of bovine dental enamel with initial erosion lesion to new erosive challenges.

This in vitro study evaluated the impact of initial erosion on the susceptibility of enamel to further erosive challenge. Thirty bovine enamel blocks were selected by surface hardness and randomized into two groups (n = 15): GC- group composed by enamel blocks without erosion lesion and GT- group composed by enamel blocks with initial erosion lesion. The baseline profile of each block was determined using the profilometer. The initial erosion was produced by immersing the blocks into HCl 0.01 M, pH 2.3 for 30 seconds, under stirring. The erosive cycling consisted of blocks immersion in hydrochloric acid (0.01 M, pH 2.3) for 2 minutes, followed by immersion in artificial saliva for 120 minutes. This procedure was repeated 4 times a day for 5 days, and the blocks were kept in artificial saliva overnight. After erosive cycling, final profile measurement was performed. Profilometry measured the enamel loss by the superposition of initial and final profiles. Data were analyzed by t-test (p<0.05). The result showed no statistically significant difference between groups (GS = 14.60±2.86 and GE = .14.69±2.21 µm). The presence of initial erosion on bovine dental enamel does not enhance its susceptibility to new erosive challenges.

Influence of removing excess of resin-based materials applied to eroded enamel on the resistance to erosive challenge.

OBJECTIVES: The aim of this study was to evaluate the effect of removing excess of resin-based materials applied to eroded enamel, subjected to erosive challenge. METHODS: Bovine enamel blocks were immersed in HCl 0.01M, pH 2.3, for 30s under agitation at 50 rpm in room temperature, in order to form a softened erosion lesion. The blocks were then randomly divided into eight groups (n=12) and treated as follows: Cn- and Ce-control without treatment, Hn- and He-fissure resin sealant (Helioseal Clear(®)), An- and Ae-self-etch adhesive (Adhese(®)), In- and Ie-infiltrant (Icon(®)); being n-with excess removal and e-without excess removal of the material. After application of the materials, the blocks were immersed in HCl for 2 min, followed by immersion in artificial saliva for 120 min. This cycle was repeated four times a day for five days. Material thickness and enamel wear were assessed using profilometry. Data were analyzed by two-way ANOVA and Tukey's test (P<0.05). RESULTS: Groups He, Ae, and Ie resulted in the formation of a layer of material over enamel, being similar effective in inhibiting erosion progression (P>0.05). Groups Hn, An, and In (with excess removal) were similar to controls (Cn, Ce) and resulted in near enamel loss after application and after erosive challenge (P>0.05). CONCLUSIONS: Resin-based materials are able to protect enamel against erosion only when they are present over enamel, as a physical barrier. CLINICAL SIGNIFICANCE: The resin-based materials demonstrated potential to prevent the progression of erosion lesions when the material remains on the dental surface.

Penetration of resin-based materials into initial erosion lesion: A confocal microscopic study.

The application of resin-based materials is an alternative of treatment for eroded lesions. Nevertheless, there are no studies about the penetration of these materials into eroded lesion, which might affect its adhesion. Therefore, this study evaluated the penetration of four resin-based materials, with and without enamel etching. By using an in vitro protocol, types of treatment were studied at five levels (AdheSE(®) , Tetric N-Bond(®) , Single Bond 2(®) , Helioseal Clear(®) , Icon(®) ) and types of enamel etching in two levels (with and without). Materials were stained with 0.02 mg/mL ethanolic solution of tetramethylrhodamine isothiocyanate. Bovine enamel samples (4 × 4 mm) were immersed in 0.01 M HCl, pH 2.3, for 30 seconds to produce initial eroded lesions. Afterward, the materials were applied on half of sample enamel surface following the manufacturer's instructions. On the other half of sample, the materials were applied without etching the enamel. Materials penetration into the enamel was assessed by Confocal Laser Scanning Microscopy on reflection and fluorescence modes. The penetration depth (PD) was measured using ImageJ software. Data were analyzed by two-way ANOVA and Tukey test (P < 0.05). Regardless of the material, etched enamel resulted in higher PD than non-etched (P < 0.05). Icon(®) showed the highest PD in enamel followed by Helioseal Clear(®) (P < 0.05), with significant difference between them (P < 0.05) and no difference was found among AdheSE(®) , Tetric N-Bond(®) , and Single Bond 2(®) (P > 0.05). It can be concluded that prior enamel etching increased the materials penetration into eroded enamel and the Icon(®) -infiltrant presented highest penetration.

Relação entre tempo de aleitamento materno, hábitos bucais deletérios e cárie dentária em bebês / The relationship between breastfeeding duration, deleterious oral habits, and dental caries in babies

A associação entre amamentação materna e cárie dentária é controversa. O presente estudo avaliou a experiência de cárie dentária entre bebês exclusivamente amamentados pelo seio materno ou pelo uso complementar de métodos artificiais auxiliares. Dados demográficos, valores do índice ceod, tempo de aleitamento materno e diagnóstico de hábitos bucais deletérios de sucção foram coletados dos prontuários clínicos-odontológicos de 299 bebês. Valores de P < 0,05 foram considerados para diferenças estatisticamente significantes. Os resultados demonstraram um significativo aumento da experiência de cárie dentária entre os bebês amamentados exclusivamente pelo seio materno. A média do tempo de aleitamento materno foi maior entre bebês com diagnóstico de cárie precoce da infância (CPI) (14,7±8,7 meses) quando comparado com bebês sem diagnóstico de CPI (8,3±6,8 meses) (P<0,001). Entretanto, bebês que desenvolveram hábitos bucais deletérios foram amamentados por menos tempo. O aleitamento materno deve ser estimulado, pois é capaz de prevenir infecções, mortalidade infantil, respiração bucal e hábitos bucais deletérios, além de favorecer o estabelecimento do vínculo emocional entre mãe e flho. Entretanto, o maior risco de lesões de cárie dentária deve determinar atenção especial da equipe de saúde da família em relação à manutenção das condições adequadas da saúde bucal dos bebês

The association between breastfeeding and dental caries is controversial. This study aimed to evaluate the experience of dental caries among exclusively breastfed infants and non-exclusively breastfed infants. Demographic data, dmft index scores, breastfeeding duration, and diagnosis of deleterious oral sucking habits were collected from 299 patient records of the Clinic of Babies of Cuiabá School of Dentistry. Statistical differences were considered to be signifcant with P values < 0.05. The results demonstrated a signifcant increase of experience of dental caries among exclusively breastfed infants. The mean of breastfeeding duration in infants with early childhood caries (ECC) diagnosis (14,7±8,7 months) was higher than those infants without ECC diagnosis (8,3±6,8 months) (P<0,001). The breastfeeding needs to be continuously estimulated because it prevents infections, infant mortality, oral breathing, deleterious oral sucking habits, besides favoring the maternal bonding. Higher risks of dental caries lesions among infants breastfed for longer, however, must lead family health teams to a special focus on the maintenance of good conditions of infants' oral health

Do technology-based devices improve carious lesion detectionin children with oral cleft? / Os aparelhos baseados em tecnologia melhoram a detecção de lesões de cárie em crianças com fissura labiopalatina?

Objetivo: Comparar o exame visual-tátil com os exames baseados em tecnologia na detecção de lesões de cárie em crianças com fissuras labiopalatina. Material e Métodos: 405 faces mesial, distal, vestibular e palatina dos dentes permanentes anteriores superiores próximos a área da fissura de 95 crianças com idade entre 6-12 anos (média 10 anos± 2 anos e 9 meses) foram avaliadas por dois examinadores previamente calibrados. Os seguintes métodos de detecção de lesão de cárie foram usados: exame visual-tátil (Método 1), exame visual-tátil com o auxílio do microscópio operatório (Método 2), exame visual por meio de um aparelho de fluorescência por LED (Método 3). ICDAS foi o sistema usado para classificar todas as lesões de cárie nos três métodos. A sonda OMS foi usada durante o exame visual-táctil. O microscópio operatório foi usado em magnificação de 10x. O aparelho de fluorescência por LED (Evince ®) tinha uma câmera ligada à peça de mão e conectada ao computador. Os métodos auxiliares de detecção de cárie foram comparados ao exame visual-táctil pelo teste de Friedman (P < 0,05). Resultados: Não houve diferença estatisticamente significante na eficácia dos métodos de detecção de lesão de cárie (P = 0,786). Conclusão: O microscópio operatório e o aparelho de fluorescência por LED não mostraram diferença na a detecção de lesão de cárie para avaliar dentes próximos à área da fissura labiopalatina.

Objective: To compare the visual-tactile examination with the technology-based caries detection examinations in children. Material and Methods: Two previously calibrated examiners assessed 405 mesial, distal, labial, and palatal surfaces of the upper anterior permanent teeth next to the cleft area of 95 children aged 6 to 12 years (mean age of 10 years ± 2 years and 9 months) with oral clefts but without the presence of any associated syndrome or craniofacial anomaly. The following detection methods were used: visual-tactile examination (Method 1), visual-tactile examination through operating microscope (Method 2), visual examination through LED-based fluorescence device (Method 3). ICDAS was the system used to score all caries lesions for all methods. WHO probe was used during the examination with visual-tactile examination. Operating microscope was used at x10 magnification. LED-based fluorescence (Evince™) had a video camera coupled to the handpiece and linked to a computer. The adjunct caries detection methods were compared to visual-tactile examination by Friedman test (P < 0.05). Results: The efficacy of carious lesion detection methods were statistically similar (P = 0.786). Conclusion: Both the operating microscope and the LED-based fluorescence device did not improve caries lesion detection in the permanent anterior teeth next to the cleft area.

Mini-implants: alternative for oral rehabilitation of a child with ectodermal dysplasia.

Ectodermal dysplasia is a rare congenital disease that affects several structures of ectodermal origin. The most commonly related oral characteristics are hypodontia, malformed teeth and underdeveloped alveolar ridges. New alternative treatments are needed due to the failure of the conventional prosthesis retention. This case report outlines the oral rehabilitation treatment of a 9-year-old girl with ectodermal dysplasia. The treatment was performed with conventional prosthesis upon mini-implants. The mini-implants provided prosthetic retention. The patient reported a good adaptation of the dental prosthesis and satisfaction with the treatment. The increased self-esteem improved the socialization skills of the girl. In this case report, use of prosthesis with mini-implants was satisfactory for prosthetic retention. However, clinical studies with long-term follow-up are needed to test the mini-implants as an alternative for oral rehabilitation of children with ectodermal dysplasia.

Mini-implants: Alternative for Oral Rehabilitation of a Child with Ectodermal Dysplasia

Ectodermal dysplasia is a rare congenital disease that affects several structures of ectodermal origin. The most commonly related oral characteristics are hypodontia, malformed teeth and underdeveloped alveolar ridges. New alternative treatments are needed due to the failure of the conventional prosthesis retention. This case report outlines the oral rehabilitation treatment of a 9-year-old girl with ectodermal dysplasia. The treatment was performed with conventional prosthesis upon mini-implants. The mini-implants provided prosthetic retention. The patient reported a good adaptation of the dental prosthesis and satisfaction with the treatment. The increased self-esteem improved the socialization skills of the girl. In this case report, use of prosthesis with mini-implants was satisfactory for prosthetic retention. However, clinical studies with long-term follow-up are needed to test the mini-implants as an alternative for oral rehabilitation of children with ectodermal dysplasia.

A displasia ectodérmica é uma doença congênita rara, que afeta várias estruturas de origem ectodérmica. As principais características na cavidade oral são hipodontia, má formação dentária e subdesenvolvimento do rebordo alveolar. Devido às falhas de retenção das próteses convencionais, novas alternativas de tratamento são necessárias. Este relato de caso descreve o tratamento de reabilitação oral em uma menina de 9 anos de idade com displasia ectodérmica. O tratamento foi realizado com próteses dentárias convencionais sobre mini-implantes. Os mini-implantes promoveram a retenção da prótese. A paciente relatou uma boa adaptação das próteses e satisfação com o tratamento. O aumento da autoestima melhorou as atividades de socialização da criança. Neste estudo de caso, o uso de prótese com mini-implantes foi satisfatória para a retenção da prótese. No entanto, estudos clínicos longitudinais são necessários para testar os mini-implantes como uma alternativa para a reabilitação oral de crianças com displasia ectodérmica.

Fatores etiológicos do bruxismo do sono: revisão de literatura / Etiology of sleep bruxism: literature review

Inúmeros estudos trazem o bruxismo como tema central, relacionando-o com vários distúrbios, tais como problemas dentários, problemas do sono, dores de cabeça e nos músculos da face. Para compreendermos profundamente essa atividade muscular que o bruxismo provoca, temos que compreender seus fatores etiológicos. Porém, o bruxismo é multifatorial e alguns estudos têm demonstrado quais fatores estão comumente associados a ele. O objetivo deste trabalho é realizar uma revisão de literatura, analisando quais fatores etiológicos são mais comumente citados em estudos sobre o bruxismo do sono

Studies having bruxism as main theme relate it to many disturbs, such as dental problems, sleep problems, headaches and facial muscle pain. The etiology is important to deeply understand the muscular activities originated by the bruxism. However, bruxism is multifactorial and some common factors are often associated. The purpose of this study is to make a literature review that analyzes which etiological factors are more often reported in sleep bruxism studies

Photodynamic inactivation of Candida albicans mediated by a low density of light energy.

Shorter times and lower energies of application of light sources are desirable to use photodynamic antimicrobial chemotherapy (PACT) to the clinical control of candidiasis, especially among babies and children. Light energies ranging from 39.5 to 100 J/cm(2) were previously applied to kill Candida albicans by PACT. The present study evaluated the efficacy of a combination of 0.05 mg/mL toluidine blue O (TBO) and a short time of application (60 s) and a low density of light energy (18 J/cm(2)) of a red light-emitting diode (LED) in killing C. albicans planktonic cells. Standard suspensions of C. albicans were randomly assigned for four treatment groups: control (L-P-), LED alone (L+P-), TBO alone (L-P+), and PACT (L+P+). After treatments, serial dilutions of suspensions were prepared and streaked on Sabouraud dextrose agar to determine colony-forming units of C. albicans per milliliter (CFU/mL). The results were analyzed by ANOVA and Tukey's post-hoc test (P < 0.05). PACT significantly reduced CFUs of C. albicans in comparison to other three treatments. Our results demonstrated a fungicidal effect of PACT mediated by a shorter time of application of LED on C. albicans planktonic cells. Further in vivo studies are needed to elucidate the efficacy of PACT to treat human fungal infections.

Oral antibacterial effect of chlorhexidine treatments and professional prophylaxis in children

Aim: The primary aim of this longitudinal study was to evaluate additional effects of 4-weekchlorhexidine digluconate (CHX) gel treatments to control Aggregatibacter actinomycetemcomitanscounts in children after professional dental prophylaxis. Porphyromonas gingivalis and Streptococcusmutans counts were also determined to evaluate the secondary effects of anti-plaque treatments onmicrobial shifts. Methods: Twenty-six children with A. actinomycetemcomitans counts >4 log10/mL of saliva and/or Quigley-Hein plaque index >3.0 were enrolled in this study. Patients wererandomly assigned to groups GI (placebo gel), GII (0.5% CHX gel), GIII (1% CHX gel), and GIV(2% CHX gel). Four sessions of treatment were performed during 4 weeks after a session ofprofessional dental prophylaxis. Real-Time polymerase chain reaction (PCR) was used todetermine viable microorganism counts in non-stimulated whole saliva samples collected atbaseline, one week, one month and three months after interruption of treatments. Results: Areduction of all bacterial counts was detected after the 3-month follow-up in all groups. Lowercounts of P. gingivalis were achieved from 1 week on after treatments. The 2% CHX concentrationseemed to contribute to lower A. actinomycetemcomitans levels and increase S. mutans levels.Conclusions: Professional dental prophylaxis was effective to control salivary levels of A.actinomycetemcomitans, P. gingivalis and S. mutans. Additional antimicrobial effects, however,were not observed by the combination of professional dental prophylaxis and 4-week chlorhexidinegel treatments.

Reconstituição estética do espaço negro gengival baseada em terapêutica multidisciplinar: relato de caso / Aesthetic reconstruction of gingival black space based on multidisciplinary therapeutic: case report

O espaço negro gengival é caracterizado por um espaço triangular na região cervical entre os incisivos, acarretando importante comprometimento estético e funcional ao indivíduo. O presente relato de caso tem por objetivo descrever o sucesso clínico do tratamento multidisciplinar de espaço negro gengival localizado entre os dentes 21 e 22 de paciente do gênero feminino, 30 anos de idade. O tracionamento ortodôntico lento foi significativo para a resolutividade deste caso, devendo sempre ser considerado para a recuperação das distâncias biológicas e manutenção da saúde periodontal do paciente.

The gingival black space problem is characterized by a triangular space in the cervical region between the upper incisors that causes aesthetic and functional implication. The purpose of this study was to describe the clinical success of a multi-disciplinary treatment of gingival black space located between the teeth 21 and 22 in a female patient aged 30. It was observed that the orthodontic slow traction was significant to solve this case, therefore, it should always be considered for recovery of biological distances and maintenance of the periodontal health of patients.

Xylitol concentrations in artificial saliva after application of different xylitol dental varnishes.

OBJECTIVE: The present study analyzed xylitol concentrations in artificial saliva over time after application of varnishes containing 10% and 20% xylitol. MATERIAL AND METHODS: Fifteen bovine enamel specimens (8x4 mm) were randomly allocated to 3 groups (n=5/group), according to the type of varnish used: 10% xylitol, 20% xylitol and no xylitol (control). After varnish application (4 mg), specimens were immersed in vials containing 500 µL of artificial saliva. Saliva samples were collected in different times (1, 8, 12, 16, 24, 48 and 72 h) and xylitol concentrations were analyzed. Data were assessed by two-way repeated-measures ANOVA (p<0.05). RESULTS: Colorimetric analysis was not able to detect xylitol in saliva samples of the control group. Salivary xylitol concentrations were significantly higher up to 8 h after application of the 20% xylitol varnish. Thereafter, the 10% xylitol varnish released larger amounts of that polyol in artificial saliva. CONCLUSIONS: Despite the results in short-term, sustained xylitol releases could be obtained when the 10% xylitol varnish was used. These varnishes seem to be viable alternatives to increase salivary xylitol levels, and therefore, should be clinically tested to confirm their effectiveness.

Xylitol concentrations in artificial saliva after application of different xylitol dental varnishes

OBJECTIVE: The present study analyzed xylitol concentrations in artificial saliva over time after application of varnishes containing 10% and 20% xylitol. MATERIAL AND METHODS: Fifteen bovine enamel specimens (8x4 mm) were randomly allocated to 3 groups (n=5/group), according to the type of varnish used: 10% xylitol, 20% xylitol and no xylitol (control). After varnish application (4 mg), specimens were immersed in vials containing 500 µL of artificial saliva. Saliva samples were collected in different times (1, 8, 12, 16, 24, 48 and 72 h) and xylitol concentrations were analyzed. Data were assessed by two-way repeated-measures ANOVA (p<0.05). RESULTS: Colorimetric analysis was not able to detect xylitol in saliva samples of the control group. Salivary xylitol concentrations were significantly higher up to 8 h after application of the 20% xylitol varnish. Thereafter, the 10% xylitol varnish released larger amounts of that polyol in artificial saliva. CONCLUSIONS: Despite the results in short-term, sustained xylitol releases could be obtained when the 10% xylitol varnish was used. These varnishes seem to be viable alternatives to increase salivary xylitol levels, and therefore, should be clinically tested to confirm their effectiveness.

Estudo dos efeitos da terapia fotodinâmica sobre Streptococcus mutans / Study of effects of photodynamic antimicrobial chemotherapy on Streptococcus mutans

Este estudo teve por objetivos (1) estudar os efeitos de diferentes parâmetros de terapia fotodinâmica sobre a viabilidade de células planctônicas e biofilme de S. mutans UA159, (2) verificar a viabilidade de uso de um modelo para crescimento de biofilme bacteriano no estudo do processo de desmineralização, (3) avaliar a capacidade da terapia fotodinâmica em controlar o processo de desmineralização mediado por biofilme de S. mutans crescidos sobre discos de dentina bovina e (4) mensurar a capacidade da terapia fotodinâmica em promover estresse celular a S. mutans UA159 com deleção do gene VicK. Os procedimentos de terapia fotodinâmica foram realizados pela associação do fotossensibilizador Photogem® e de um LED vermelho visível (Biotable®, 630 nm, 50 mW/cm2) como fonte de luz. A viabilidade de células bacterianas foi determinada por dois métodos distintos: teste de atividade metabólica pelo uso da resazurina (etapa 1) e contagem de UFC (etapas 1,2 e 3). Microrradiografia transversal e análise da concentração de cálcio por espectrometria de absorção atômica foram os métodos de escolha para a determinação do perfil do conteúdo mineral (%vol), perda mineral integrada (PMI, %vol x m), profundidade de lesão (PL, m) e concentração de cálcio liberado em meio de cultura (mg/dL). A intensidade de fluorescência emitida pela modulação da proteína GFP após ensaio de estresse celular foi determinada por citometria de fluxo. Os diferentes parâmetros de terapia fotodinâmica foram capazes de reduzir a viabilidade de células planctônicas de S. mutans, bem como das células organizadas em biofilme (ANOVA a um critério, Games-Howell, p<0,05), sendo o resultado dose-dependente. Quando Photogem® a 0,25 mg/mL foi associado ao LED a 150 J/cm2, uma redução de aproximadamente 3,9 log10 na contagem de células viáveis provenientes de biofilme foi observada. O modelo para crescimento de biofilme permitu a progressão do processo de...

The present study aimed (1) to assess the effects of different parameters of Photodynamic Antimicrobial Chemotherapy (PACT) on the viability of planktonic cells and biofilm of S. mutans UA159, (2) to test the effectiveness of a biofilm model in evaluating the demineralization process, (3) to assess the influence of PACT on the control of demineralization process mediated by S. mutans biofilm growth on dentin discs, and (4) to measure the ability of PACT in promoting cellular stress on S. mutans UA159 knockout vicK gene. PACT procedures were performed by association between a photosensitizer (Photogem®) and a visible red LED (Biotable®, 630 nm, 50 mW/cm2) as light source. Viability of bacterial cells was determined by two distinct methods: resazurin assay (phase 1) and Colony Forming Unit (CFU) counts (phases 1, 2, and 3). Transversal microradiography and calcium release analysis by atomic absorption spectrometry were chosen to analyze mineral content profile (%vol), integrated mineral loss (IML, %vol x m), lesion depth (LD, m), and concentration of calcium release in culture media (mg/dL). Fluorescence intensity levels, which were modulated by expression of Green Fluorescent Protein-reporter (GFP) after cellular stress, were measured by flow cytometer. A dose-dependent effect on the reduction of viability of planktonic cells and biofilm of S. mutans was observed after application of different parameters of PACT (one-way ANOVA, Games-Howell, p<0.05). 0.25 mg/mL Photogem® plus 150 J/cm2 LED decreased in nearly 3.9 log10 the viability of S. mutans biofilm. Progression of demineralization process was correlated with the time (24 h IML: 1905±391 vol% x m, LD: 69.9±12,2 m; 48 h - IML: 3529±886 vol% x m, LD: 114.2±24.6 m; 72 h - IML: 4186±1099 vol% x m, LD: 146.1±20.1 m). Integrated mineral loss, lesion depth and concentration of calcium release...

Estudo dos efeitos da terapia fotodinâmica sobre Streptococcus mutans / Study of effects of photodynamic antimicrobial chemotherapy on Streptococcus mutans

Este estudo teve por objetivos (1) estudar os efeitos de diferentes parâmetros de terapia fotodinâmica sobre a viabilidade de células planctônicas e biofilme de S. mutans UA159, (2) verificar a viabilidade de uso de um modelo para crescimento de biofilme bacteriano no estudo do processo de desmineralização, (3) avaliar a capacidade da terapia fotodinâmica em controlar o processo de desmineralização mediado por biofilme de S. mutans crescidos sobre discos de dentina bovina e (4) mensurar a capacidade da terapia fotodinâmica em promover estresse celular a S. mutans UA159 com deleção do gene VicK. Os procedimentos de terapia fotodinâmica foram realizados pela associação do fotossensibilizador Photogem® e de um LED vermelho visível (Biotable®, 630 nm, 50 mW/cm2) como fonte de luz. A viabilidade de células bacterianas foi determinada por dois métodos distintos: teste de atividade metabólica pelo uso da resazurina (etapa 1) e contagem de UFC (etapas 1,2 e 3). Microrradiografia transversal e análise da concentração de cálcio por espectrometria de absorção atômica foram os métodos de escolha para a determinação do perfil do conteúdo mineral (%vol), perda mineral integrada (PMI, %vol x m), profundidade de lesão (PL, m) e concentração de cálcio liberado em meio de cultura (mg/dL). A intensidade de fluorescência emitida pela modulação da proteína GFP após ensaio de estresse celular foi determinada por citometria de fluxo. Os diferentes parâmetros de terapia fotodinâmica foram capazes de reduzir a viabilidade de células planctônicas de S. mutans, bem como das células organizadas em biofilme (ANOVA a um critério, Games-Howell, p<0,05), sendo o resultado dose-dependente. Quando Photogem® a 0,25 mg/mL foi associado ao LED a 150 J/cm2, uma redução de aproximadamente 3,9 log10 na contagem de células viáveis provenientes de biofilme foi observada. O modelo para crescimento de biofilme permitu a progressão do processo de...

The present study aimed (1) to assess the effects of different parameters of Photodynamic Antimicrobial Chemotherapy (PACT) on the viability of planktonic cells and biofilm of S. mutans UA159, (2) to test the effectiveness of a biofilm model in evaluating the demineralization process, (3) to assess the influence of PACT on the control of demineralization process mediated by S. mutans biofilm growth on dentin discs, and (4) to measure the ability of PACT in promoting cellular stress on S. mutans UA159 knockout vicK gene. PACT procedures were performed by association between a photosensitizer (Photogem®) and a visible red LED (Biotable®, 630 nm, 50 mW/cm2) as light source. Viability of bacterial cells was determined by two distinct methods: resazurin assay (phase 1) and Colony Forming Unit (CFU) counts (phases 1, 2, and 3). Transversal microradiography and calcium release analysis by atomic absorption spectrometry were chosen to analyze mineral content profile (%vol), integrated mineral loss (IML, %vol x m), lesion depth (LD, m), and concentration of calcium release in culture media (mg/dL). Fluorescence intensity levels, which were modulated by expression of Green Fluorescent Protein-reporter (GFP) after cellular stress, were measured by flow cytometer. A dose-dependent effect on the reduction of viability of planktonic cells and biofilm of S. mutans was observed after application of different parameters of PACT (one-way ANOVA, Games-Howell, p<0.05). 0.25 mg/mL Photogem® plus 150 J/cm2 LED decreased in nearly 3.9 log10 the viability of S. mutans biofilm. Progression of demineralization process was correlated with the time (24 h IML: 1905±391 vol% x m, LD: 69.9±12,2 m; 48 h - IML: 3529±886 vol% x m, LD: 114.2±24.6 m; 72 h - IML: 4186±1099 vol% x m, LD: 146.1±20.1 m). Integrated mineral loss, lesion depth and concentration of calcium release...

The use of xylitol as a strategy for prevention of dental caries / Utilização do xilitol como uma estratégia para prevenção da cárie dentária

Dental caries is a multifactorial disease, which depends on the fermentation of carbohydrates by microorganisms of the dental biofilm. Xylitol is a sugar-alcohol, which cannot be fermented by oral cariogenic bacteria. This article aimed to review the literature on the use of xylitol for prevention of dental caries. There is little conclusive scientific evidence about this subject, although several studies have been performed. The development of products and clinical protocols should be based on studies with sound experimental design, which will permit the understanding of clinical and laboratorial parameters, such as mecanisms of action, vehicles of delivery, dose-response effects, and frequency of use of the polyol. Clarification of the potential and limitations of the use of xylitol for prevention of dental caries would help clinicians to select preventive protocols more efficient and cost-effective for specific groups.

A cárie dentária é uma doença multifatorial, dependente da fermentação de carboidratos por microrganismos formadores do biofilme dentário. O xilitol é um açúcar-álcool que não pode ser fermentado por bactérias orais cariogênicas. Esta revisão da literatura teve por objetivo propiciar o maior entendimento sobre o uso do xilitol na prevenção da cárie dentária. Apesar de inúmeros trabalhos realizados na área, poucas são as evidências científicas sobre o tema. O desenvolvimento de produtos e protocolos capazes de tornar o xilitol mais eficiente e eficaz contra a cárie dentária só será possível através da realização de estudos mais bem delineados, pautados no entendimento de parâmetros clínicos e laboratoriais, como mecanismos de ação, veículo de administração, efeito dose-resposta e frequência de uso. O esclarecimento do potencial e das limitações de uso do xilitol para prevenção de cárie dentária auxiliaria o cirurgião dentista na seleção de protocolos preventivos mais eficientes e com melhor custobenefício para grupos específicos.