Photobiomodulation therapy for oral mucositis management in head and neck cancer patients undergoing radiotherapy: case reports

Introduction: Photobiomodulation therapy (PBM) has been recommended for the prevention of oral mucositis (OM). Objective: to evaluate the use of PBM to prevent and control the severity of oral mucositis lesions and painful sensitivity in patients undergoing radiotherapy for head and neck cancer (HNC) treatment. Case reports: Eight patients with HNC attended for radiotherapy treatment, either associated with chemotherapy, or not were followed up. Clinical evaluation was performed, including meticulous anamnesis. The patients were followed up throughout the entire period of radiotherapy treatment. For the protocol of prophylaxis of OM, low level laser equipment was used, with a wavelength in the range of 660nm, in a contact mode, 30 mW of continuous emission 4J/cm² three times per week and for the therapeutic protocol wavelength in the range of 660nm, in a contact mode, 30 mW of continuous emission 8 J/cm², in the respective areas compromised by oral mucositis, 3 times per week till the complete remission of the lesions. All the patients were clinically followed up from the beginning of the antineoplastic therapy up to the conclusion of the medical treatment or total remission of the oral lesion, involving post radiotherapy control. A visual analog scale (VAS) was used to measure pain every week. Results: A progressive development of the lesions was observed from the 1st to the 5th week. Remission of OM was observed from the 7th week up to the conclusion of treatment. There is a continuous increase in the pain process, attaining the maximum level in the 6th week, with decline occurring up to the 7th week. Conclusion: Photobiomodulation therapy was able to control the severity of OM lesions and painful sensitivity in patients undergoing radiotherapy for head and neck cancer treatment, avoiding the interruption of the cancer therapy.

Introdução: A terapia com fotobiomodulação (FBM) tem sido recomendada para a prevenção da mucosite oral (MO). Objetivo: avaliar o uso de FBM para prevenir e controlar a gravidade das lesões da mucosite oral e a sensibilidade dolorosa em pacientes submetidos à radioterapia para tratamento de câncer de cabeça e pescoço (CCP). Relato dos casos: Oito pacientes com CCP atendidos para tratamento radioterápico, associado ou não à quimioterapia, foram acompanhados. Foi realizada avaliação clínica, incluindo anamnese meticulosa. Os pacientes foram acompanhados durante todo o período de tratamento radioterápico. Para o protocolo de profilaxia de MO, foi utilizado um equipamento laser de baixa potência, com comprimento de onda na faixa de 660nm, em modo de contato e 30 mW de emissão contínua com 4J/cm2. Para o protocolo terapêutico, e para comprimento de onda na faixa de 660nm, em modo de contato e 30 mW de emissão contínua com 8J/cm2 na área da lesão, até sua completa remissão. Todos os pacientes foram acompanhados clinicamente desde o início da terapia antineoplásica até a conclusão do tratamento médico ou remissão total da lesão oral, envolvendo o controle pós-radioterapia. Uma escala visual analógica (EVA) foi usada para medir a dor semanalmente. Resultados: Observou-se um desenvolvimento progressivo das lesões da 1ª à 5ª semana. A remissão da mucosite oral foi observada a partir da 7ª semana até o final do tratamento. Houve um aumento contínuo do processo doloroso, atingindo o nível máximo na 6ª semana, com declínio ocorrendo até a 7ª semana. Conclusão: A terapia de fotobiomodulação foi capaz de controlar a gravidade das lesões de MO e a sensibilidade dolorosa em pacientes submetidos à radioterapia para tratamento do câncer de cabeça e pescoço, evitando a interrupção da terapia oncológica.

An In Vitro Evaluation of Human Enamel Surfaces Subjected to Erosive Challenge After Bleaching.

OBJECTIVES: This study aimed to evaluate whether tooth enamel bleached with hydrogen peroxide (H2 O2 ) is more susceptible to erosion when compared with unbleached tooth enamel; and whether the presence of calcium (Ca) in the bleaching gel influenced this process. MATERIALS AND METHODS: Enamel blocks were prepared from human molars, and submitted to surface microhardness analysis (baseline). Blocks were prepared and randomly divided into four treatment groups (n = 20): G1 and G2-bleached with 7.5% H2 O2 , with and without Ca, respectively; G3 and G4-bleached with 35% H2 O2 , with and without Ca, respectively. After bleaching, these groups were submitted to an erosive challenge with 1% citric acid. G5 and G6 (n = 20, each) were the negative (without bleaching) and positive controls (without bleaching, but with erosion), respectively. The percentage of surface hardness loss (%SHL), the 3D non-contact profilometry and Scanning Electron Microscopy (SEM) analyses were performed. RESULTS: G2 showed the highest %SHL after bleaching. G1 presented the lowest %SHL in comparison with G2, G3, G4, and G6 after erosion (p < 0.05), which was confirmed only by the SEM analysis. CONCLUSION: It is suggested that low concentration of H2 O2 with calcium can be recommended for at-home bleaching agents, which may avoid the mineral loss of bleached enamel after an erosive challenge. CLINICAL SIGNIFICANCE: Low concentration of H2 02 with calcium can be recommended for at-home bleaching agents, which may avoid the mineral loss of bleached enamel after an erosive challenge. (J Esthet Restor Dent 29:128-136, 2017).

Assessment of maxillary bone density by the tomodensitometric scale in Cone-Beam Computed Tomography (CBCT) / Avaliação da densidade óssea dos maxilares por meio de escala tomodensitométrica em Tomografia Computadorizada de Feixe Cônico (TCFC)

Objective ­ To analyze bone density in images of the anterior and posterior regions of the mandible and maxilla obtained with ConeBeam Computed Tomography. Planning of surgeries for implant placement requires information about bone density, which is directly related to stability. Methods ­ This retrospective study included female (25) and male (25) patients (50) with ages in the range 30-40/45 years. Images of their exams (200 transaxial slices; 2-mm thick) were analyzed in the anterior (50) and posterior (50) regions of the mandible and anterior (50) and posterior (50) regions of the maxilla using the bone density tool of the Xoran (i-CAT®) software. Our data were compared and correlated with computed tomography data obtained in the literature. Results ­ Mean gray values were utilized to determine the density values for the anterior mandible (562.2, 3.3) and maxilla (531.3, 2.8) and the posterior mandible (503.8, 3.0) and maxilla (394.5, 2.9). The results were statistically analyzed for correlation between our findings and those of the literature. The t test was utilized to obtain additional information related to gender; and the Pearson correlation analysis was utilized to assess the differences between observers 1 and 2. Conclusions ­ Statistically significant differences (p>0.05) between densities in the anterior and posterior regions were not found, and our values were consistent with those in the literature obtained with Computed Tomography.

Objetivo ­ Analisar a densidade óssea nas regiões anterior e posterior dos maxilares em imagens obtidas por meio de Tomografia Computadorizada de Feixe Cônico. O planejamento de cirurgias requer informações sobre a densidade óssea da região escolhida para instalação de implantes. Métodos ­ Este estudo retrospectivo incluiu 50 pacientes, sendo 25 do gênero feminino e 25 masculino com idades na faixa 30-40/45 anos. As imagens de seus exames (200 cortes transaxiais com espessura de 2 mm) foram analisadas nas regiões anterior (50) e posterior (50) da mandíbula e anterior (50) e posterior (50) da maxila usando a ferramenta de densidade óssea do software Xoran (tomógrafo i-CAT®). Os nossos dados foram comparados e correlacionados com aqueles de tomografia computadorizada obtidos na literatura. Resultados ­ Valores médios de cinza foram usados para determinar os valores de densidade para mandíbula (562,2; 3,3) e maxila (531,3; 2,8) anteriores, e mandíbula (503,8; 3,0) e maxila (394,5; 2,9) posteriores. Os resultados foram submetidos à análise estatística para comparação entre os achados deste estudo e aqueles da literatura. O teste t foi usado para obter informações adicionais relacionadas aos gêneros; e a análise de correlação de Pearson foi usada para avaliar a diferença entre os observadores 1 e 2. Conclusões ­ Diferenças estatisticamente significantes (p< 0,05) entre as densidades nas regiões anterior e posterior não foram encontradas, e os valores que nós obtivemos com Tomografia Computadorizada de Feixe Cônico foram compatíveis com aqueles da literatura com Tomografia Computadorizada.

Dental bleaching agents with calcium and their effects on enamel microhardness and morphology

Aim: To evaluate enamel microhardness and morphology after bleaching with hydrogen peroxide containing calcium in different concentrations. Methods: One hundred specimens of human teeth were ground and polished and had the initial microhardness evaluated. The specimens were randomly assigned into five groups (n=20): Group 1 - Control group (no treatment); Group 2 - Home Peroxide 6% (without calcium); Group 3 - Home Peroxide 7.5% (without calcium); Group 4 - White Class 6% (with calcium); Group 5 - White Class 7.5% (with calcium). For each group, the bleaching was performed according to the manufacturer's specifications. The specimens were bleached once a day for 5 days and subjected to pH cycling. Microhardness and scanning electron microscopy (SEM) analysis were performed before and after bleaching. Results: The results showed that groups submitted to bleaching treatment presented hardness loss compared to the control group. The group of 7.5% hydrogen peroxide with calcium showed a lower percentage of hardness loss in relation to other groups. Conclusion: Calcium in association with a higher hydrogen peroxide concentration may decrease microhardness changes on enamel.

Assessment of bone healing in rabbit calvaria grafted with three different biomaterials.

This study evaluated the bone regeneration process in rabbit calvaria induced by three types of biomaterials: two xenogenous, consisting of deproteinized bovine bone, while the other was alloplastic, based on biphasic calcium phosphate. Five New Zealand white rabbits weighing between 2,900 and 3,500 g were submitted to four standard 8 mm-diameter perforations at the parietal bone. Three perforations were filled with three grafts and biomaterials, two of them received bovine Bio-Oss® and Endobon® Xenograft Granules, and the other consisted of fully alloplastic Straumann® Bone Ceramic. The fourth remaining cavity was used as control with coagulum. After eight weeks, the animals were sacrificed, and the samples were prepared for morphometric and qualitative analysis. The cavities filled with alloplastic biomaterials showed higher percentages of newly formed bone (p<0.05), while the cavities with xenogenous biomaterials showed higher amount of residual graft (p<0.05). Although the results showed greater bone formation with Straumann® Bone Ceramic, further studies are required to prove which is the more effective biomaterial for bone induction process.

Assessment of Bone Healing in Rabbit Calvaria Grafted with Three Different Biomaterials

This study evaluated the bone regeneration process in rabbit calvaria induced by three types of biomaterials: two xenogenous, consisting of deproteinized bovine bone, while the other was alloplastic, based on biphasic calcium phosphate. Five New Zealand white rabbits weighing between 2,900 and 3,500 g were submitted to four standard 8 mm-diameter perforations at the parietal bone. Three perforations were filled with three grafts and biomaterials, two of them received bovine Bio-Oss(r) and Endobon(r) Xenograft Granules, and the other consisted of fully alloplastic Straumann(r) Bone Ceramic. The fourth remaining cavity was used as control with coagulum. After eight weeks, the animals were sacrificed, and the samples were prepared for morphometric and qualitative analysis. The cavities filled with alloplastic biomaterials showed higher percentages of newly formed bone (p<0.05), while the cavities with xenogenous biomaterials showed higher amount of residual graft (p<0.05). Although the results showed greater bone formation with Straumann(r) Bone Ceramic, further studies are required to prove which is the more effective biomaterial for bone induction process.

Este estudo avaliou o processo de reparação óssea induzida por três biomateriais, dois de origem xenógena constituído de osso bovino desproteinizado e um aloplástico à base de fosfato de cálcio bifásico, em calota craniana de coelhos. Em cinco coelhos brancos da Nova Zelândia com peso entre 2.900 e 3.500 g, foram realizadas quatro perfurações padronizadas de 8 mm de diâmetro nos ossos parietais e enxertados dois biomateriais de origem bovina: Bio-Oss(r) e Endobon(r) Xenograft Granules e um totalmente aloplástico: Straumann(r)Bone Ceramic. Uma cavidade permaneceu com coágulo e foi utilizado como controle. Após oito semanas os animais foram sacrificados e as amostras preparadas para análise morfométrica e qualitativa. Os resultados mostraram que as cavidades preenchidas com o biomaterial aloplástico apresentaram percentualmente maior quantidade de osso neoformado (p<0,05). Apesar dos resultados mostrarem maior neoformação óssea pelo Straumann(r)Bone Ceramic, há a necessidade de mais estudos para se comprovar qual biomaterial é mais efetivo no processo de indução óssea.

Effect of chlorhexidine on the 18-month clinical performance of two adhesives.

PURPOSE: This study tested the hypothesis that 2% chlorhexidine (CHX) does not affect the 18-month clinical performance of two dentin adhesives, XP Bond (XPB) and XENO V (XEN). MATERIALS AND METHODS: A total of 120 noncarious cervical lesions (NCCL) were selected and assigned to 4 groups: (1) XPB; (2) CHX prior to the application of XPB; (3) XEN; (4) CHX prior to the application of XEN. A hybrid composite resin, Esthet•X, was used for all restorations. Restorations were evaluated blindly at 6 and 18 months by two evaluators using the University of North Carolina (UNC)-modified USPHS criteria. Statistical analyses included the Mann Whitney and McNemar nonparametric tests (p < 0.05). RESULTS: At 6 months, 91 (75.2%) restorations were evaluated, while 92 (76.7%) restorations were evaluated at 18 months. The 6-month/18-month overall retention rates (%) were 100/100 for XPB, 96.0/95.0 for CHX+XPB, 100/91.3 for XEN, and 100/95.8 for CHX+XEN with no statistical difference between any pair of groups at each recall. Sensitivity to air improved significantly for groups XPB, XEN, and CHX+XEN from pre-operative conditions to 1 week after insertion, to 6 and to 18 months after inserting. For group CHX+XPB, there was a statistically significant difference only between pre-operative conditions and 1 week after insertion. Marginal adaptation deteriorated for all groups, but no statistically significant differences were found. All other criteria remained statistically similar. CONCLUSION: The application of CHX prior to the dentin adhesive did not influence the 6-month/18-month clinical performance of the two adhesives.

Avaliação e comparação da satisfação de pacientes reabilitados na região mandibular com prótese total convencional ou overdenture implantorretida estabilizada com attachment bola / Evaluation and comparison of patient satisfation regarding conventional and ball-attached, implant-retained mandibular overdentures

Objetivo: avaliar e comparar o nível de satisfação de pacientes que receberam próteses totais convencionais (PTC) ou overdentures implantorretidas (OIR) estabilizadas com attachment bola na região mandibular. Material e Métodos: aplicação de questionário composto por fatores de satisfação (adaptação, retenção, mastigação, fonética, conforto, condições de higienização, estética e autoestima) e por níveis de satisfação (insatisfeito, satisfeito e muito satisfeito), em 124 pacientes com idade média de 55 anos, divididos em dois grupos: grupo PTC (n = 60) e grupo OIR (n = 64). Resultados: os dados obtidos foram analisados através de análise estatística descritiva e inferencial (teste de Mann-Whitney) e mostraram que os pacientes que receberam OIR demonstraram maior satisfação em todos os fatores avaliados (p < 0,05). Conclusão: a OIR proporciona maior satisfação aos pacientes quando comparada com a PTC; no entanto, há necessidade de mais estudos comparativos em relação a seleção das amostras e aplicação de outros instrumentos de avaliação

Objective: the aim of this study was to evaluate and compare satisfaction levels of patients receiving conventional dentures (CDS) or implant-retained mandibular overdentures (IROVD) with ball attachments. Material and Methods: one-hundred and twenty four patients (mean age 55 years) were divided into two groups: CD (n = 60) and IROVD (n = 64). A questionnaire consisting of several factors (adaptation, retention, chewing, phonetics, comfort, oral hygiene, esthetics, and self-esteem) and levels of satisfaction (unsatisfied, satisfied, and very satisfied) was applied. Descriptive and inferential statistics (Mann-Whitney) were performed. Results: IROVD patients demonstrated greater satisfaction for all factors evaluated (p < 0.05). Conclusion: the IROVD provides better results than CDS. However, there is a need for more comparative studies regarding sample selection and the use of other evaluation instruments.

Avaliação da microdureza em resinas compostas fotopolimerizadas com sistemas de luz halógena e diodo emissor de luz / Evaluation of microhardness on polymerization's photo of resin composites by helogen light and light emitting diode

O objetivo deste estudo foi o de avaliar a microdureza de duas resinas compostas, uma compactável (Tetric Ceram) e outra do tipo flow (Tetric Flow), utilizando-se duas fontes de luz, uma halógena e outra à base de diodo emissor de luz (LED). Foram confeccionados quarenta corpos de prova, utilizando-se uma matriz de teflon, e divididos em quatro grupos: Grupo I - Tetric Ceram Halógena; Grupo II - Tetric Ceram LED; Grupo III - Tetric Flow Halógena e Grupo IV - Tetric Flow LED. Após o lixamento e polimento dos corpos de prova, foi realizada a análise da microdureza (Vickers) nas regiões de topo e de base em cada amostra. A análise de variância (ANOVA) e o teste de Tukey foram aplicados ao nível de significância de 5%. Os resultados mostraram que a fonte de luz halógena foi estatisticamente mais efetiva (p=0,05) que o LED na microdureza superficial; quando comparados os tipos de resina compostas, a Tetric Ceram apresentou valores de microdureza estatisticamente maiores (p,<,05) que a Tetric Flow, e as regiões de topo apresentaram microdureza maior (p<0,05) em relação às regiões de base, independente da fonte de luz e do material resinoso utilizado. Os resultados sugerem que a fonte de luz halógena é mais efetiva que o LED.

The light curing of resin composite by halogen light is frequent in dental. Therefore the emitting diodes (LEDs), have been suggested in opposite to halogen light, which can present more advantages. The aim of this study was to evaluate the microhardness of the two resin composites, a condensable resin (Tetric Ceram) and other flow resin (Tetric Flow), using two light curing units, a halogen light (Ultarlux EL) and a LED (Ultraled XP). Forty specimens (5x5x6mm) were obtained using a matrix of teflon and dividing in four groups: Group I - Halogen Tetric Ceram; Group II - LED Tetric Ceram; Group III - Halogen Tetric Flow e Grupo IV - LED Tetric Flow. After the sandpaper and the polish of specimens, the Vickers' microhardness analysis on top and base was measured in all specimens. The values obtained were submitted to a two-way variation of ANOVA analysis and the pared test t (Student's) to level of 5% significance. The results showed that source halogen light was more effective (p?0,05) than LED. When two types of resin composite were compared, the Tetric Ceram presented microhardness values higher (p?0,05) than Tetric Flow and the top regions obtained microhardness values higher (p?0,05) in relation to base regions independently of light unit used. The results suggest that halogen light curing unit is more effective than LED.

Evaluation of organic and inorganic compounds in the saliva of patients with chronic periodontal disease / Avaliação de compostos orgânicos e inorgânicos na saliva de pacientes com doença periodontal crônica

The aim of this study was to evaluate the influence of periodontal disease on the biochemical parameters of the saliva, including salivary flow rate, pH, total protein, alkaline phosphatase activity and urea concentration, in individuals with chronic periodontitis. Methods: Forty subjects were allocated into two groups: twenty subjects without periodontal disease (control group) and twenty subjects with chronic periodontitis (test group). Plaque index (PI), gingival index (GI), probing depth (PD) and clinical attachment level (CAL) were obtained by a previously trained and calibrated clinical examiner. Saliva from both groups was collected for analysis of its biochemical parameters. The Student’s t-test and correlation coefficient (Pearson) were used at a 5% level of significance. Results: The results showed alterations in the alkaline phosphatase activity, urea concentration and total protein in the subjects of the test group compared to the control group (P<0.05). However, there was no correlation between the clinical periodontal parameters and the salivary parameters (P>0.05). Conclusion: The results suggest that chronic periodontitis can affect the composition of the saliva and that analysis of the salivary parameters can be useful as an additional exam for the diagnosis of periodontal disease.

Objetivo: O objetivo deste estudo foi avaliar a influência da doença periodontal sobre os parâmetros bioquímicos da saliva, incluindo taxa de fluxo salivar, pH, proteína total, atividade de fosfatase alcalina e a concentração de uréia, em indivíduos com periodontite crônica. Metodologia: Quarenta indivíduos foram alocados em dois grupos: vinte indivíduos sem doença periodontal (grupo controle) e vinte indivíduos com periodontite crônica (grupo teste). Índice de placa (IP), índice gengival (IG), profundidade de sondagem (PD) e nível de inserção clínica (CAL) foram obtidos anteriormente por um examinador treinado e calibrado clinicamente. Saliva de ambos os grupos foram coletadas para análise de seus parâmetros bioquímicos. O teste T de Student e coeficiente de correlação (Pearson) foram utilizados em um nível 5% de significância. Resultados: Os resultados mostraram alterações na atividade da fosfatase alcalina, uréia e proteína total nos indivíduos do grupo teste em comparação ao grupo controle (P<0,05). No entanto, não houve correlação entre os parâmetros clínicos periodontais e os parâmetros salivares (P>0,05).Conclusão: Os resultados sugerem que a periodontite crônica pode afetar a composição da saliva e que a análise dos parâmetros salivares pode ser útil como um exame complementar para o diagnóstico da doença periodontal.

Clinical and microbiological effects of an essential-oil-containing mouth rinse applied in the "one-stage full-mouth disinfection" protocol--a randomized doubled-blinded preliminary study.

The aim of this randomized double-blinded preliminary study was to evaluate the clinical and microbiological long-term effects of an essential-oil-containing mouth rinse as the active agent utilized in the "one-stage full-mouth disinfection protocol." Probing pocket depth and plaque and gingival indices were evaluated by the same calibrated examiner in all teeth of 20 moderate chronic periodontitis subjects. Presence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythensis were determined by polymerase chain reaction in nonstimulated saliva, tongue dorsum, and pooled subgingival samples. The subjects were randomized into two groups: full-mouth disinfection plus essential oils (Listerine) or full-mouth disinfection plus placebo. Clinical and microbial parameters were evaluated at baseline (T0), 45 (T1) and 180 (T2) days after therapy and analyzed using analysis of variance, Student t, and Wilcoxon tests (p < 0.05). No significant differences were observed between groups regarding clinical measurements at baseline. However, in the later examinations, T1 and T2, the test group always presented higher reductions of pocket depth, plaque index, and gingival index compared to the control group. The essential-oils group revealed significant reduction on occurrence of P. gingivalis in saliva comparing baseline and 45 days; this difference still remain at 180 days. The essential-oil-containing mouth rinse demonstrated beneficial effects on clinical parameters. Microbiological findings were less consistent. The results of this preliminary study suggest further investigations.

pH-cycling models to evaluate the effect of low fluoride dentifrice on enamel de- and remineralization.

Since the currently available pH-cycling models do not differentiate the anti-caries potential of dentifrices with low fluoride (F) concentration, two models were developed and tested in the present. Bovine enamel blocks were subjected to the models and treated with F solutions containing from 70 to 280 microg F/mL in order to validate them in terms of dose-response effect. The models were also tested by evaluating the dentifrices Colgate Baby (500 microg F/g, as a low fluoride dentifrice), Tandy (1,100 microg F/g, as an active F-dentifrice) and Crest (1,100 microg F/g, as positive control). Enamel mineral loss or gain was assessed by surface and cross-sectional microhardness, and lesion depth was analyzed by polarized light microscopy. The pH-cycling models showed F dose-response effect either reducing enamel demineralization or enhancing remineralization. The low F dentifrice presented anti-caries potential, but it was not equivalent to the dentifrices containing 1,100 microg F/g. These data suggest that the models developed in this study were able to evaluate the anti-caries potential of low F dentifrice either on resistance to demineralization or on enhancement of remineralization.

pH-cycling models to evaluate the effect of low fluoride dentifrice on enamel de- and remineralization

Since the currently available pH-cycling models do not differentiate the anti-caries potential of dentifrices with low fluoride (F) concentration, two models were developed and tested in the present. Bovine enamel blocks were subjected to the models and treated with F solutions containing from 70 to 280 mug F/mL in order to validate them in terms of dose-response effect. The models were also tested by evaluating the dentifrices Colgate Baby (500 mug F/g, as a low fluoride dentifrice), Tandy (1,100 mug F/g, as an active F-dentifrice) and Crest (1,100 mug F/g, as positive control). Enamel mineral loss or gain was assessed by surface and cross-sectional microhardness, and lesion depth was analyzed by polarized light microscopy. The pH-cycling models showed F dose-response effect either reducing enamel demineralization or enhancing remineralization. The low F dentifrice presented anti-caries potential, but it was not equivalent to the dentifrices containing 1,100 mug F/g. These data suggest that the models developed in this study were able to evaluate the anti-caries potential of low F dentifrice either on resistance to demineralization or on enhancement of remineralization.

Tendo em vista que os modelos atuais de ciclagens de pH não diferenciam o potencial anti-cárie de dentifrícios com baixa concentração de fluoreto (F), dois modelos foram desenvolvidos e testados. Blocos de esmalte bovino foram submetidos aos modelos e tratados com soluções de concentrações crescentes de F (70 a 280 mig F/mL) para validar os modelos em termos de dose-resposta. A seguir, os modelos foram testados avaliando o potencial anti-cárie dos dentifrícios Colgate Baby (500 mig F/g, dentifrício de baixa concentração), Tandy (1.100 mig F/g, como controle ativo) e Crest (1.100 mig F/g, como controle positivo). Perda ou ganho de mineral pelo esmalte foi avaliada por microdureza e profundidade de lesão de cárie foi avaliada por microscopia de luz polarizada. Os modelos de ciclagens de pH desenvolvidos mostraram efeito do F dose-resposta quer seja na redução da desmineralização como na remineralização do esmalte. O dentifrício de baixa concentração de F mostrou ter potencial anti-cárie, o qual não foi equivalente aos dentifrícios contendo 1.100 mig F/g. Os resultados sugerem que os modelos desenvolvidos são capazes de avaliar o potencial anti-cárie de dentifrício de concentração reduzida de F, quer seja na sua capacidade de aumentar a resistência do esmalte a desmineralização como na ativação da remineralização.

Alkali-soluble fluoride deposition on enamel after professional application of topical fluoride in vitro

Considerando que a eficácia dos produtos para aplicação tópica profissional de flúor (géis, espumas e vernizes) está relacionada com a reatividade do flúor (F) com o esmalte e sendo esta dependente da disponibilidade do F em cada produto, este estudo foi conduzido. A concentração de F nos seguintes produtos foi estudada: I - Flúor Fosfato Acidulado (FFA) gel (1,23% F), II - FFA espuma (1,23% F) e III- Verniz fluoretado (2,26% F). Foram confeccionados 40 blocos de esmalte bovino, tratados de acordo com os grupos descritos, sendo um deles utilizado como controle. O F fracamente ligado (''CaF2'') ao esmalte foi determinado após a extração com 1.0 M KOH e analisado em eletrodo específico. A concentração de F encontrada no gel foi de 12.642, na espuma 12.755 e no verniz 23.183 mg F/g. Todos os produtos formaram uma quantidade significantemente maior de ''CaF2'' na superfície do esmalte, comparado ao grupo controle (p < 0,05), mas entre eles, esta diferença não foi significante (p > 0,05). Assim, a formação de ''CaF2'' na superfície do esmalte não foi proporcional ao conteúdo de F nos produtos, sugerindo que o pH e o veículo utilizado são mais importantes.

Fluoride and aluminum in teas and tea-based beverages.

OBJECTIVE: To evaluate fluoride and aluminum concentration in herbal, black, ready-to-drink, and imported teas available in Brazil considering the risks fluoride and aluminum pose to oral and general health, respectively. METHODS: One-hundred and seventy-seven samples of herbal and black tea, 11 types of imported tea and 21 samples of ready-to-drink tea were divided into four groups: I-herbal tea; II-Brazilian black tea (Camellia sinensis); III-imported tea (Camellia sinensis); IV-ready-to-drink tea-based beverages. Fluoride and aluminum were analyzed using ion-selective electrode and atomic absorption, respectively. RESULTS: Fluoride and aluminum levels in herbal teas were very low, but high amounts were found in black and ready-to-drink teas. Aluminum found in all samples analyzed can be considered safe to general health. However, considering 0.07 mg F/kg/day as the upper limit of fluoride intake with regard to undesirable dental fluorosis, some teas exceed the daily intake limit for children. CONCLUSIONS: Brazilian and imported teas made from Camellia sinensis as well as some tea-based beverages are sources of significant amounts of fluoride, and their intake may increase the risk of developing dental fluorosis.

Fluoride and aluminum in teas and tea-based beverages

OBJECTIVE: To evaluate fluoride and aluminum concentration in herbal, black, ready-to-drink, and imported teas available in Brazil considering the risks fluoride and aluminum pose to oral and general health, respectively. METHODS: One-hundred and seventy-seven samples of herbal and black tea, 11 types of imported tea and 21 samples of ready-to-drink tea were divided into four groups: I-herbal tea; II-Brazilian black tea (Camellia sinensis); III-imported tea (Camellia sinensis); IV-ready-to-drink tea-based beverages. Fluoride and aluminum were analyzed using ion-selective electrode and atomic absorption, respectively. RESULTS: Fluoride and aluminum levels in herbal teas were very low, but high amounts were found in black and ready-to-drink teas. Aluminum found in all samples analyzed can be considered safe to general health. However, considering 0.07 mg F/kg/day as the upper limit of fluoride intake with regard to undesirable dental fluorosis, some teas exceed the daily intake limit for children. CONCLUSIONS: Brazilian and imported teas made from Camellia sinensis as well as some tea-based beverages are sources of significant amounts of fluoride, and their intake may increase the risk of developing dental fluorosis.

Alkali-soluble fluoride deposition on enamel after professional application of topical fluoride in vitro.

Since the efficacy of topical fluoride products is related to the fluoride (F) availability and its reactivity with enamel, this study was conducted. The F concentration of the following materials was verified: I- acidulated phosphate fluoride (APF) gel (1.23% F), II- APF foam (1.23% F) and III- Varnish (2.26% F). Forty blocks of bovine enamel were divided into 4 groups and treated according to the materials described, being one of them used as control. Loosely bound fluoride (''CaF2'') was determined on enamel after extraction with 1.0M KOH and analyzed by ion-selective electrode. Total F concentration found in gel was 12,642, in foam 12,755 and in varnish 23,183 mg F/g. All products formed statistically higher amounts of ''CaF2'' on enamel compared to the control group (p < 0.05), but the difference between them was not significant (p > 0.05). Thus, ''CaF2'' formation was not proportional to the total F content in the products, suggesting that the pH and the vehicle used are more important.

Relationship between stressful situations, salivary flow rate and oral volatile sulfur-containing compounds.

The relationship between stress, salivary flow rate and oral volatile sulfur-containing compounds (VSCs) is not clearly established. Two stressful situations were studied: psychological stress caused by a biochemistry examination (Study I) and psychophysiological stress caused by premenstrual syndrome (PMS) (Study II). Seventy-one undergraduate dental students took part in Study I and VSCs were measured 1 wk before the examination, on the day of examination and 1 wk after. In Study II, 50 women were selected (23 with and 27 without PMS) and the measurements were made during non-menstrual, premenstrual and menstrual stages. Unstimulated salivary flow was determined in the subjects of both studies. On the day of the biochemistry examination, VSCs significantly increased and salivary flow decreased compared with baseline values. Women with PMS showed higher VSC concentrations during the premenstrual stage than those without PMS (P < 0.05), but the salivary flow was not statistically different. A change in VSCs was observed during different stages of the menstrual cycle for the groups of women, but the salivary flow did not change. The results suggest that a stressful situation can be a predisposing factor for the increase of VSCs in the mouth air, but the mechanism cannot be simply explained by reduction of the salivary flow.