Dental Fluorosis Treatment Can Improve the Individuals' OHRQoL? Results from a Randomized Clinical Trial.

This study aimed to evaluate the effect on oral health-related quality of life (OHRQoL) of two treatment protocols for dental fluorosis in individuals enrolled in a randomized clinical trial. Seventy volunteers, who lived in a fluorosis endemic area in Brazil, and had at least four maxillary anterior teeth showing fluorosis with a Thylstrup and Fejerskov index from 1 to 7, were randomized into two treatment groups (n= 35): GI- enamel microabrasion; or GII- microabrasion associated with at-home bleaching. Microabrasion was performed using 37% phosphoric acid and pumice, and at-home tooth bleaching with 10% carbamide peroxide in a tray. Volunteers completed a questionnaire at baseline and 1-month post treatment to assess changes in OHRQoL, using the Oral Impact on Daily Performance (OIDP). Differences in overall impact scores between and within treatment groups were analyzed with Wilcoxon (within) and Mann-Whitney (between) tests. Changes in performance scores were analyzed using Wilcoxon tests (a< 0.05). One month after treatment, subjects reported improvement in OHRQoL. Both groups showed lower OIDP scores (p< 0.001), but there was no difference between them. Eating, cleaning teeth, smiling and emotional state performance scores were lower after treatment for the whole sample. In conclusion, the treatment with microabrasion improved the OHRQoL in this sample of individuals living in a fluorosis endemic area regardless of the addition of at-home bleaching.

Dental fluorosis treatment can improve the individuals' ohrqol? results from a randomized clinical trial

Abstract This study aimed to evaluate the effect on oral health-related quality of life (OHRQoL) of two treatment protocols for dental fluorosis in individuals enrolled in a randomized clinical trial. Seventy volunteers, who lived in a fluorosis endemic area in Brazil, and had at least four maxillary anterior teeth showing fluorosis with a Thylstrup and Fejerskov index from 1 to 7, were randomized into two treatment groups (n= 35): GI- enamel microabrasion; or GII- microabrasion associated with at-home bleaching. Microabrasion was performed using 37% phosphoric acid and pumice, and at-home tooth bleaching with 10% carbamide peroxide in a tray. Volunteers completed a questionnaire at baseline and 1-month post treatment to assess changes in OHRQoL, using the Oral Impact on Daily Performance (OIDP). Differences in overall impact scores between and within treatment groups were analyzed with Wilcoxon (within) and Mann-Whitney (between) tests. Changes in performance scores were analyzed using Wilcoxon tests (a< 0.05). One month after treatment, subjects reported improvement in OHRQoL. Both groups showed lower OIDP scores (p< 0.001), but there was no difference between them. Eating, cleaning teeth, smiling and emotional state performance scores were lower after treatment for the whole sample. In conclusion, the treatment with microabrasion improved the OHRQoL in this sample of individuals living in a fluorosis endemic area regardless of the addition of at-home bleaching.

Resumo Este estudo teve como objetivo avaliar o efeito na qualidade de vida relacionada à saúde bucal (QVRSB) de dois protocolos de tratamento para fluorose dentária, em indivíduos incluídos em um ensaio clínico randomizado. Setenta voluntários, os quais viviam em uma área de fluorose endêmica no Brasil, e que possuíam pelo menos quatro dentes ântero-superiores com índice de Thylstrup e Fejerskov de 1 a 7, foram randomizados em dois grupos de tratamento (n= 35): GI- microabrasão de esmalte; ou GII- microabrasão associada com clareamento caseiro. A microabrasão foi realizada com ácido fosfórico 37% e pedra pomes e, o clareamento caseiro com peróxido de carbamida 10% e uso de moldeira. Os voluntários responderam um questionário antes e 1 mês após o tratamento, visando avaliar mudanças na QVRSB através do instrumento Oral Impact on Daily Performance (OIDP). Diferenças nos escores de impacto geral entre e nos mesmos grupos de tratamento foram analisadas através dos testes Wilcoxon (mesmo grupo) e Mann-Whitney (entre grupos), respectivamente. Alterações no escores dos domínios foram analisadas usando o teste Wilcoxon (a<0.05). Um mês após o tratamento, os indivíduos relataram melhora na QVRSB. Ambos os grupos apresentaram menores escores do OIDP (p<0,001), sem diferença entre eles. Os escores dos domínios comer, limpar os dentes, sorrir e estado emocioal diminuíram após o tratamento para toda a amostra. Concluiu-se que o tratamento com microabrasão melhorou a QVRSB de indivíduos vivendo em uma área de fluorose endêmica independentemente da associação com o clareamento caseiro.

Does active application of universal adhesives to enamel in self-etch mode improve their performance?

OBJECTIVES: To evaluate the effect of adhesion strategy on the enamel microshear bond strengths (µSBS), etching pattern, and in situ degree of conversion (DC) of seven universal adhesives. METHODS: 84 extracted third molars were sectioned in four parts (buccal, lingual, proximal) and divided into 21 groups, according to the combination of the main factors adhesive (AdheSE Universal [ADU], All-Bond Universal [ABU], Clearfil Universal [CFU], Futurabond U [FBU], G-Bond Plus [GBP], Prime&Bond Elect (PBE), and Scotchbond Universal Adhesive [SBU]), and adhesion strategy (etch-and-rinse, active self-etch, and passive self-etch). Specimens were stored in water (37°C/24h) and tested at 1.0mm/min (µSBS). Enamel-resin interfaces were evaluated for DC using micro-Raman spectroscopy. The enamel-etching pattern was evaluated under a field-emission scanning electron microscope (direct and replica techniques). Data were analyzed with two-way ANOVA and Tukey's test (α=0.05). RESULTS: Active self-etch application increased µSBS and DC for five out of the seven universal adhesives when compared to passive application (p<0.001). A deeper enamel-etching pattern was observed for all universal adhesives in the etch-and-rinse strategy. A slight improvement in etching ability was observed in active self-etch application compared to that of passive self-etch application. Replicas of GBP and PBE applied in active self-etch mode displayed morphological features compatible with water droplets. The DC of GBP and PBE were not affected by the application/strategy mode. CONCLUSIONS: In light of the improved performance of universal adhesives when applied actively in SE mode, selective enamel etching with phosphoric acid may not be crucial for their adhesion to enamel. CLINICAL SIGNIFICANCE: The active application of universal adhesives in self-etch mode may be a practical alternative to enamel etching in specific clinical situations.

Dinâmica da população de coliformes durante a compostagem automatizada de dejetos líquidos de suínos / Population dynamics during composting of fecal automated pig slurry

Microrganismos presentes em dejetos de suínos podem contaminar o meio ambiente. Embora a compostagem seja preconizada como um método eficiente para reduzir este potencial poluidor dos dejetos, existem poucas informações de pesquisa sobre tal processo. O presente trabalho teve o objetivo de avaliar a eficiência da compostagem automatizada dos dejetos líquidos de suínos (DLS) na redução da população de coliformes, usados como indicadores de poluição fecal. Os DLS foram adicionados periodicamente, durante 106 dias, em substrato constituído pela mistura, em partes iguais, de maravalha e serragem. Foram efetuadas 14 adições de DLS, e em cada adição as leiras de compostagem eram revolvidas por meio de uma máquina especialmente desenvolvida para este fim. Foram avaliados dois tratamentos com três repetições, sendo um com e outro sem adição de ácido fosfórico aos dejetos, até pH 6,0. A adição de ácido visou reduzir as perdas de N por volatilização de amônia (NH3) durante a compostagem. A avaliação da população de coliformes foi feita pela técnica do número mais provável (NMP), com uso do caldo Fluorocult, incubado a 37ºC por 24h e posterior leitura em luz ultravioleta. A população de coliformes fecais não foi afetada pela adição de ácido fosfórico. O processo de compostagem automatizada foi eficiente na redução de coliformes fecais, cuja população original passou de 4,2x1010 para 1,2 x 105 ao final da compostagem (156 dias) sem adição de ácido e de 3,8x1010 para 2,3x104 na compostagem com adição de ácido. Essa remoção de coliformes fecais, promovida pela compostagem automatizada dos dejetos líquidos de suínos, corresponde a 99,99 por cento...

Microorganisms present in pig manure can contaminate the environment. Although composting is recommended as an efficient method to reduce the pollution potential of waste, there is little research information on this process. This study aimed to evaluate the efficiency of automated composting of pig slurry (PS) in reducing the population of coliforms, used as fecal pollution indicators. The PS was added periodically during 106 days in substrate, with a mixture, in equal parts, of wood shavings and sawdust. There were 14 additions of PS and at each addition the compost windrows were revolved through a machine especially developed for this purpose. Two treatments with three replications were evaluated, one with and one without the addition of phosphoric acid to the slurry up to pH 6.0. The acid addition aimed to reduce N losses through the volatilization of ammonia (NH3) during composting. Coliforms were evaluated by the technique of most probable number (MPN) using the Fluorocult broth, incubated at 37 ° C for 24 h and subsequent reading in ultra violet light. The population of fecal coliforms was not affected by the addition of phosphoric acid. The automated composting process was effective in reducing faecal coliforms, whose original population decreased from 4.2 x 1010 to 1.2 x 105 at the end of composting (156 days) without addition of acid and from 3.8 x1010 to 2,3 x104 in compost with added acid. This removal of faecal coliforms, promoted by automated composting of pig slurry, corresponds to 99.99 percent...

Dinâmica da população de coliformes durante a compostagem automatizada de dejetos líquidos de suínos / Population dynamics during composting of fecal automated pig slurry

Microrganismos presentes em dejetos de suínos podem contaminar o meio ambiente. Embora a compostagem seja preconizada como um método eficiente para reduzir este potencial poluidor dos dejetos, existem poucas informações de pesquisa sobre tal processo. O presente trabalho teve o objetivo de avaliar a eficiência da compostagem automatizada dos dejetos líquidos de suínos (DLS) na redução da população de coliformes, usados como indicadores de poluição fecal. Os DLS foram adicionados periodicamente, durante 106 dias, em substrato constituído pela mistura, em partes iguais, de maravalha e serragem. Foram efetuadas 14 adições de DLS, e em cada adição as leiras de compostagem eram revolvidas por meio de uma máquina especialmente desenvolvida para este fim. Foram avaliados dois tratamentos com três repetições, sendo um com e outro sem adição de ácido fosfórico aos dejetos, até pH 6,0. A adição de ácido visou reduzir as perdas de N por volatilização de amônia (NH3) durante a compostagem. A avaliação da população de coliformes foi feita pela técnica do número mais provável (NMP), com uso do caldo Fluorocult, incubado a 37ºC por 24h e posterior leitura em luz ultravioleta. A população de coliformes fecais não foi afetada pela adição de ácido fosfórico. O processo de compostagem automatizada foi eficiente na redução de coliformes fecais, cuja população original passou de 4,2x1010 para 1,2 x 105 ao final da compostagem (156 dias) sem adição de ácido e de 3,8x1010 para 2,3x104 na compostagem com adição de ácido. Essa remoção de coliformes fecais, promovida pela compostagem automatizada dos dejetos líquidos de suínos, corresponde a 99,99 por cento.(AU)

Microorganisms present in pig manure can contaminate the environment. Although composting is recommended as an efficient method to reduce the pollution potential of waste, there is little research information on this process. This study aimed to evaluate the efficiency of automated composting of pig slurry (PS) in reducing the population of coliforms, used as fecal pollution indicators. The PS was added periodically during 106 days in substrate, with a mixture, in equal parts, of wood shavings and sawdust. There were 14 additions of PS and at each addition the compost windrows were revolved through a machine especially developed for this purpose. Two treatments with three replications were evaluated, one with and one without the addition of phosphoric acid to the slurry up to pH 6.0. The acid addition aimed to reduce N losses through the volatilization of ammonia (NH3) during composting. Coliforms were evaluated by the technique of most probable number (MPN) using the Fluorocult broth, incubated at 37 ° C for 24 h and subsequent reading in ultra violet light. The population of fecal coliforms was not affected by the addition of phosphoric acid. The automated composting process was effective in reducing faecal coliforms, whose original population decreased from 4.2 x 1010 to 1.2 x 105 at the end of composting (156 days) without addition of acid and from 3.8 x1010 to 2,3 x104 in compost with added acid. This removal of faecal coliforms, promoted by automated composting of pig slurry, corresponds to 99.99 percent.(AU)

Acid etching concentration as a strategy to improve the adhesive performance on Er:YAG laser and bur-prepared demineralized enamel.

OBJECTIVE: This study investigated the effect of phosphoric acid concentration on microshear bond strength (µSBS) of an etch-and-rinse adhesive system to demineralized irradiated enamel. BACKGROUND DATA: Er:YAG laser irradiation may increase acid resistance of enamel; however, its use is associated with reduced bonding effectiveness. MATERIALS AND METHODS: Three experimental etching agents and one bonding agent were fabricated. Enamel pretreatment was tested in two levels (bur and laser) and phosphoric acid was tested in four levels (control and at 35, 45, or 55%). Commercially available phosphoric acid and a bonding agent were used as control. Enamel samples were submitted to a pH-cycling model to induce demineralization. Half of the exposed demineralized enamel area was prepared with diamond bur and half was prepared with an Er:YAG laser (λ=2.94 µm, 300 mJ, 2 Hz). Specimens were randomly allocated to receive different acid etching concentrations and either the experimental or the commercial adhesive system. Microshear bond strength and the adhesive remnant index (ARI) scores were determined. µSBS's data were evaluated by two way analysis of variance (ANOVA) and Tukey's test. Kruskal-Wallis followed by Dunn's method and Mann-Whitney test were used for ARI comparisons (α=5%). RESULTS: For µSBS, no significant difference among the groups was found, either for phosphoric acid concentration or surface preparation. For ARI scores, statistically higher resin retention was found for lased groups (p<0.001). CONCLUSIONS: The increase of phosphoric acid concentration did not impair bond strength regardless of surface preparation; however, increased retention was found when demineralized enamel was prepared with laser.

Effect of organic acids and mannanoligosaccharide on excretion of Salmonella typhimurium in experimentally infected growing pigs.

The effect of organic acids and mannanoligosaccharide addition to the diet was assessed in pigs orally inoculated with Salmonella typhimurium. Forty-six growers were distributed among four treatments: Basal Diet (BD); BD+encapsulated organic acids; BD+free organic acids; BD+mannanoligosaccharide. Seroconversion was monitored, and feces and tissue samples were tested for Salmonella isolation. No treatment prevented the carrier state, but a tendency of lower fecal excretion was observed in the group treated with mannanoligosaccharide.

Efficacy of smear layer removal by cavity cleaning solutions: an atomic force microscopy study / Eficácia da remoção da lama dentinária por soluções de limpeza cavitária: estudo de microscopia de força atômica

PURPOSE: To evaluate the efficacy of smear layer removal by cavity cleaning agents by the use of atomic force microscopy (AFM). METHODS: Five intact human third molars were sectioned in the coronal portion to obtain dentin disks, which were ground with 600-grit abrasive paper for 10 s. Serial longitudinal sections were made perpendicular to each other to create four specimens, from each tooth. The specimens were divided into four treatment groups: GI, 2 percent chlorhexidine; GII, calcium hydroxide solution; GIII, 1.23 percent fluoride solution; and GIV, 37 percent phosphoric acid. The solutions were applied with a brush for 60 s, with the exception of the 37 percent phosphoric acid, which was applied for 15 s and rinsed with distilled water for 60 s. The specimens were examined by AFM. RESULTS: All of the specimens in GI and GII showed 100 percent of the dentin tubules obliterated by the smear layer. However, all of the specimens in GIII and GIV showed 0 percent of the dentin tubules obliterated by the smear layer. CONCLUSION: The 1.23 percent fluoride solution was effective in removing the smear layer and can be used as a cavity cleanser.

OBJETIVO: Avaliar a eficácia da remoção de lama dentinária por agentes de limpeza cavitária através da análise de microscopia de força atômica (MFA). METODOLOGIA: Cinco terceiros molares humanos hígidos foram seccionados transversalmente na porção coronária, obtendo discos de dentina de 2 mm, que foram desgastados com lixas de granulação 600, por 10 s.Foram feitos cortes seriados longitudinais e perpendiculares entre si, obtendo-se quarto espécimes de cada dente. Os espécimes foram divididos em 4 grupos: GI- clorexidina a 2 por cento; GII- água de hidróxido de cálcio; GIII- solução fluoretada a 1,23 por cento; GIV - ácido fosfórico 37 por cento. As soluções foram aplicadas com pincel por 60 s, com exceção do ácido fosfórico que foi aplicado por 15 s e lavado com água destilada pelo mesmo tempo. Os espécimes foram analisados por MFA. RESULTADOS: Todos os espécimes de GI e GII apresentaram 100 por cento dos túbulos dentinários obliterados por lama dentinária. Os espécimes de GIII e GIV apresentaram 0 por cento dos túbulos obliterados por lama dentinária. CONCLUSÃO: A solução de fluoretada a 1,23 por cento foi eficiente na remoção de lama dentinária, podendo ser empregada na limpeza de cavidades.

Morphology of the dentin on primary molars after the application of phosphoric acid under different conditions.

The aim of this study was to evaluate changes in the superficial dentin pattern of primary teeth after applying different phosphoric acid concentrations and conditioning times. Twenty-four dentin surfaces were divided in 4 groups with 10 teeth each: GI -no treatment; GII to GIV -phosphoric acid at 37%, 32%, and 10% respectively. The samples were divided into two halves: one treated for 7 seconds (T1) and the other one for 15 seconds (T2). They were submitted to scanning electronic microscopy (SEM). A reticule was superimposed upon the images to randomly select dentinal tubules measured in µm². The conditioning times did not cause significant differences in the mean diameter values of the dentin tubules within each test group: GII (T1= 4.86; T2= 4.70); GIII (T1 = 3.83; T2= 3.08); GIV (T1= 5.04; T2= 5.23). Comparing different groups, there were no differences in T1. The same results were observed in T2, except for GIV which presented higher mean diameter values than GIII. The extent of acid conditioning did not influence tubule opening within groups. When different types of acids where compared, only the 10% phosphoric acid showed upper tubule opening than 32% phosphoric acid. The dentin pattern varied according to the type of acid used for conditioning.

Morphology of the dentin on primary molars after the application of phosphoric acid under different conditions

The aim of this study was to evaluate changes in the superficial dentin pattern of primary teeth after applying different phosphoric acid concentrations and conditioning times. Twenty-four dentin surfaces were divided in 4 groups with 10 teeth each: GI -no treatment; GII to GIV -phosphoric acid at 37 percent, 32 percent, and 10 percent respectively. The samples were divided into two halves: one treated for 7 seconds (T1) and the other one for 15 seconds (T2). They were submitted to scanning electronic microscopy (SEM). A reticule was superimposed upon the images to randomly select dentinal tubules measured in µm². The conditioning times did not cause significant differences in the mean diameter values of the dentin tubules within each test group: GII (T1= 4.86; T2= 4.70); GIII (T1 = 3.83; T2= 3.08); GIV (T1= 5.04; T2= 5.23). Comparing different groups, there were no differences in T1. The same results were observed in T2, except for GIV which presented higher mean diameter values than GIII. The extent of acid conditioning did not influence tubule opening within groups. When different types of acids where compared, only the 10 percent phosphoric acid showed upper tubule opening than 32 percent phosphoric acid. The dentin pattern varied according to the type of acid used for conditioning.

Influence of intracoronal bleaching agents on the ultimate strength and ultrastructure morphology of dentine.

OBJECTIVE: To evaluate the effects of intracoronal bleaching on ultimate tensile strength (UTS) of sound and etched dentine and its ultrastructure morphology. METHODOLOGY: Bovine dentine specimens with (e) or without previous etching with 37% phosphoric acid for 15 s were used for the intracoronal bleaching experiments. Teeth were randomly assigned to five treatments (n = 10): (C) control--no bleaching, (SP) sodium perborate, (CP) 35% carbamide peroxide, (25% HP) 25% hydrogen peroxide and (35% HP) 35% hydrogen peroxide. Bleaching was performed four times within a 72 h interval and afterwards, dentine pulp chamber blocks were obtained. The blocks were sectioned in 0.7 mm-thick slices and these were trimmed to reduce the inner dentine to a dumbbell shape with a cross-sectional area of 0.8 mm(2). Specimens were tested with the microtensile method (0.5 mm min(-1)) and data were analysed (two-way ANOVA-Tukey test, P < 0.05). Additional teeth were prepared for transmission electron microscopy (TEM) to evaluate dentine ultramorphology. RESULTS: The mean values of the UTS (SD) in MPa for sound dentine were: C = 48.3(8.5)a, SP = 34.6 (8.2)b, CP = 32.9 (8.9)b, 25% HP = 28.0(4.6)b, 35% HP = 26.4(6.6)b, and pre-etched dentine: Ce = 38.9(13.8)a, SPe = 31.3 (9.3)ab, CPe = 28.4 (6.2)ab, 25% HPe = 30.0 (7.9)ab, 35% HPe = 19.9(4.6)b. Significant differences between the means are indicated by the letters. TEM observations exhibited demineralization areas for all bleaching treatments. CONCLUSION: Bleaching decreased dentine UTS after treatment. Pre-etched not-bleached dentine (Ce) presented UTS similar to pre-etched bleached dentine, except for 35% HPe. The decrease of UTS of bleached dentine could be attributed to ultrastructural alterations such as loss of inorganic components.

Primary tooth enamel loss after manual and mechanical microabrasion.

PURPOSE: This study's purpose was to assess the amount of dental enamel loss on primary incisors after manual or mechanical microabrasion with a phosphoric acid/pumice paste. METHODS: Ten exfoliated primary maxillary incisors were bisected faciolingually and the resulting 20 halves were randomly assigned to 2 groups: group 1 (N = 10)-manual technique (plastic spatula); and group 2 (N = 10)-mechanical technique (rubber cup attached to a low-speed handpiece). Microabrasion was performed on the buccal surface using an abrasive paste prepared with 37% phosphoric acid and pumice. Ten 20-second applications alternated with 20-second risings were performed in each group. Enamel thickness measurements made under stereomicroscopy before and after microabrasion were analyzed statistically by analysis of variance and pairwise t test. RESULTS: There was a statistically significant difference (P = .003) between the manual and mechanical techniques. The mechanical technique produced a mean enamel loss of 274.16 microm (66% of total enamel thickness), while the mean enamel loss with the manual technique was 152.59 microm (39% of total enamel thickness). CONCLUSION: Manual microabrasion using a plastic spatula removed less enamel, but was sufficient to eliminate most superficial stains and defects, and may be a viable option for the microabrasive technique on primary teeth.

Microabrasão como tratamento de esmalte fluorótico / Microabrasion as treatment of enamel fluorosis

Atualmente há forte tendência internacional a opinião favorável sobre a importância da utilização do flúor como coadjuvante na redução dos índices de cárie, tanto em países desenvolvidos quanto subdesenvolvidos. Todavia, simultaneamente os índices de fluorose dental parecem crescer em proporção inversa. Esta ocorre como resultado da intoxicação crônica por flúor, ocasionada pela ingestão acima do limite adequado por um período de tempo prolongado. A microabrasão do esmalte é um método efetivo para remover descolorações superficiais que esta condição provoca no esmalte, afetando sua estética. A utilização de ácido clorídrico a 18% associado à pedra pomes apesar de ser simples e de baixo custo foi paulatinamente substituída devido ao ácido clorídrico ser de alto risco de causar alguns danos aos tecidos periodontais. Por este motivo, este trabalho mostra um caso clínico de tratamento de fluorose de esmalte resolvido com microabrasão, usando o ácido fosfórico. A ingestão deliberada de creme dental foi a provável causa das manchas. Devido à posição do dentes na arcada e à amplitude do sorriso do paciente, selecionaram-se apenas os seis dentes anteriores superiores para receberem o tratamento proposto. Quatro sessões, intervaladas por sete dias cada, foram executadas, utilizando-se pasta de pedra pomes e ácido fosfórico a 37%. Nas duas primeiras sessões, sob isolamento absoluto do campo operatório, friccionou-se a pasta sobre o esmalte com taça de borracha acionada por micromotor de baixa rotação, e nas regiões de difícil usou-se tiras de lixa. Nas duas últimas sessões, foram feitos apenas pequenos retoques, fricionando-se a pasta com espátula de madeira manualmente.

There is currently a trend in favor of using fluoride as a coadjuvant in reducing caries indexes, as much in underdeveloped as in developed countries. However, simultaneously the indexes of dental fluorosis seem to grow in an inverse proportion. This is brought about by chronic ingestion of fluoride for a prolonged length of time or in high concentration. Enamel microabrasion is an effective method to remove superficial stains caused by this condition, which affects esthetics of that tissue. The use of 18% hydrochloric acid in association with pumice, despite being a simple and low cost method, has been gradually replaced due to its potential of causing damage to periodontal tissues. Thus, this article reports the treatment of a fluorosis clinical case solved with microabrasion using phosphoric acid 37%, because its cost-benefit is supposedly better than with chloridric acid. The deliberate ingestion of toothpaste was the probable cause of the tooth stains. Due to the location of the teeth and to the patient's smile, only the six upper anterior teeth were selected to receive the proposed treatment. Four clinical sessions, with a seven days interval between each other, were carried out using 37% phosphoric acid and pumice. Under rubber dam isolation, the two first sessions consisted of rubbing the acid-pumice mix on enamel surface using a rubber cup on slow speed, and abrasive paper strips on the interproximal tooth surfaces. On the two final sessions, only finishing touches were performed using a wooden spatula to manually rub the acid-pumice paste.

Design and bioevaluation of a 32P-patch for brachytherapy of skin diseases.

The purpose of this study was to design and evaluate a 32P patch for brachytherapy of skin diseases. We employed Phosphoric-32P-acid and Chromic 32P-phosphate in combination with natural rubber or silicone to produce the patches. Stability studies in vitro to evaluate the leakage of radioactivity, autoradiographic studies to evaluate homogeneity and shielding, as well as therapeutic efficacy in an animal model of skin cancer of the selected 32P patch were performed. The 32P-silicone-patch demonstrated its safety for external application. Tumor growth was arrest and complete regressions of tumors were seen in some other cases with 40 Gy applied in a single-dose scheme. In conclusion, the 32P-silicone-patch is easy to prepare and use in the treatment of skin diseases.

Effect of air abrasion on tensile bond strength of a single-bottle adhesive/indirect composite system to enamel.

This study evaluated the efficiency of air abrasion alone and associated with phosphoric acid etching on tensile bond strength of a single-bottle adhesive/indirect composite restorative system (Bond 1/Alert) to human enamel. Forty enamel surfaces from extracted human third molars were assigned to 4 groups (n= 10). Mach 4.1 (Kreativ Inc.) air abrasion equipment was used for 20 s. A special system of rod pairs aligned in a specific apparatus was used for tensile strength tests, according to ISO/TR 11405 standard (1994) with some modifications. Bond strength means were: G1 (air abrasion + rinsing + condensable composite resin Alert) = 3.46 +/- 0.83 MPa; G2 (air abrasion + rinsing + Bond 1 adhesive system + Alert) = 4.00 +/- 1.60 MPa; G3 (air abrasion + rinsing + 37% phosphoric acid + rinsing + Bond 1 + Alert) = 20.80 +/- 3.95 MPa; and G4 (37% phosphoric acid + rinsing + Bond 1 + Alert) = 17.00 +/- 2.74 MPa. The statistical analysis by Kruskal-Wallis test revealed that G1 and G2 presented statistically significant difference (p< 0.05) from G3 and G4 (p<0.01) and G1 and G3 did not differ significantly (p> 0.05) from G2 and G4, respectively.

Density and diameter of dentinal tubules in etched and non-etched bovine dentine examined by scanning electron microscopy.

Bovine teeth have been widely used in studies focusing adhesion to dentine over the last years. However, little is known about main structural aspects of bovine dentine, especially regarding density and diameter of its tubules. Thirty bovine incisors were randomly divided into two groups. In group I, teeth were cross-sectioned at three depths: outer, middle and inner. The dentinal surfaces were etched with 35% phosphoric acid for 90s. In group II, the teeth were fractured at the same three depths. All the specimens were processed and examined in a Jeol 6100 SEM. Fifteen micrographs from each depth were obtained for the two groups at a magnification of 2500x. To determine the diameter of the dentinal tubules, the LEICA Q500 MC software was used. All the results were statistically processed in the EXCEL software. The dentinal tubules were wider at the outer regions (GI: 5.21+/-0.64microm; GII: 2.30+/-0.09microm) than that at the inner regions (GI: 2.71+/-0.72microm; GII: 1.77+/-0.06microm). Tubular density was higher at the inner regions (50310+/-11178tubules/mm(2)) than that at the outer regions (18772+/-2951tubules/mm(2)). In addition, the peritubular dentine was wider at the outer depth than at the inner one. Our results showed that bovine dentine possesses some structural aspects different from those previously reported for human dentine, mainly related to the diameter of dentinal tubules and to the thickness of peritubular dentine at the several depths.

Effect of air abrasion on tensile bond strength of a single-bottle adhesive/indirect composite system to enamel

This study evaluated the efficiency of air abrasion alone and associated with phosphoric acid etching on tensile bond strength of a single-bottle adhesive/indirect composite restorative system (Bond 1/Alert) to human enamel. Forty enamel surfaces from extracted human third molars were assigned to 4 groups (n= 10). Mach 4.1 (Kreativ Inc.) air abrasion equipment was used for 20 s. A special system of rod pairs aligned in a specific apparatus was used for tensile strength tests, according to ISO/TR 11405 standard (1994) with some modifications. Bond strength means were: G1 (air abrasion + rinsing + condensable composite resin Alert) = 3.46 ± 0.83 MPa; G2 (air abrasion + rinsing + Bond 1 adhesive system + Alert) = 4.00 ± 1.60 MPa; G3 (air abrasion + rinsing + 37 percent phosphoric acid + rinsing + Bond 1 + Alert) = 20.80 ± 3.95 MPa; and G4 (37 percent phosphoric acid + rinsing + Bond 1 + Alert) = 17.00 ± 2.74 MPa. The statistical analysis by Kruskal-Wallis test revealed that G1 and G2 presented statistically significant difference (p< 0.05) from G3 and G4 (p<0.01) and G1 and G3 did not differ significantly (p> 0.05) from G2 and G4, respectively.

O objetivo deste estudo foi avaliar a eficiência da abrasão a ar associada ou não ao condicionamento com ácido fosfórico na resistência à tração de um sistema restaurador composto por adesivo frasco único/resina composta indireta (Bond 1/Alert) ao esmalte humano. Quarenta superfícies de esmalte de terceiros molares humanos extraídos foram alocadas em 4 grupos (n=10). Foi utilizado o sistema de ar abrasivo Mach 4.1 (Kreativ Inc.) durante 20 s. Um sistema especial de pares de hastes alinhadas em um equipamento específico foi usado para realização dos testes de tração, de acordo com a Norma ISO/TR 11405 (1994) com algumas modificações. Os valores médios obtidos foram: G1 (ar abrasivo + lavagem + resina condensável Alert) = 3,46 ± 0,83 MPa; G2 (ar abrasivo + lavagem + adesivo Bond 1 + Alert) = 4,00 ± 1,60 MPa; G3 (ar abrasivo + lavagem + ácido fosfórico 37 por cento + lavagem + Bond 1 + Alert) = 20,80 ± 3,95 MPa; e G4 (ácido fosfórico 37 por cento + lavagem + Bond 1 + Alert) = 17,00 ± 2,74 MPa. Pela análise estatística (teste Kruskal Wallis), G1 e G2 apresentaram diferença estatisticamente significante em relação a G3 e G4 (p<0,01) e G1 e G3 não diferiram dos grupos G2 e G4, respectivamente (p>0,05).

Direct pulp capping with a dentin bonding system in human teeth: a clinical and histological evaluation.

This study evaluated the pulpal response in human dental pulp to direct pulp capping with the Single Bond Adhesive System (SBAS) after 10% or 37% phosphoric acid etching and after capping with Calcium Hydroxide (CH). The degree of bleeding and hemostasis conditions was considered during the adhesive technique. The pulps of 78 sound premolars were capped with SBAS after 37% phosphoric acid etching (Group I) or 10% phosphoric acid etching (Group II) and CH (Group III-control). The cavities were restored with a resin composite (Charisma). After 1, 3, 7 and 30 days, the teeth were extracted and processed for light microscopical examination (H/E, AgNOR silver stain and Brown-Brenn). The patients were followed for postoperative symptomatology evaluation. Clinical results showed the possibility of hemostasis with saline solution only. There was no statistical difference between bleeding generated by 10% and 37% acid solutions. In some cases, contact of the pulp tissue with SASB started the bleeding process, thus damaging the adhesive technique. The histological response was similar in Groups I and II, without signs of cellular differentiation and dentin neoformation up to 30 days. Bacteria were not observed in any specimens. In the control group (CH) at day 7, the pulps exhibited cells with high synthetic activity (Ag-NOR-positive) underneath the area of coagulation necrosis. Dentin bridging was observed at the thirtieth day. The postoperative period was asymptomatic for all groups. In conclusion, SBAS should be avoided for vital pulp therapy, while CH remains the capping agent of choice for mechanically exposed human dental pulp.

Effect of a self-etching primer on shear bond strength of adhesive precoated brackets in vivo.

The aim of this study was to evaluate the influence of a self-etching primer (SEP) (Transbond Plus SEP, 3M Unitek, Monrovia, Calif) on shear bond strength of adhesive uncoated and precoated Victory brackets (3M Unitek). The sample group consisted of 23 patients, with four premolars each, equally divided in four different groups. Brackets were bonded in vivo by the same operator using a split-mouth random technique: group 1, 37% phosphoric acid + primer + composite + conventional Victory bracket; group 2, 37% phosphoric acid + primer + precoated Victory bracket; group 3, SEP + composite + conventional bracket; group 4, SEP + precoated bracket. After 30 days, premolars were extracted for orthodontic reasons and a Universal Instron Machine was used to apply an occlusal shear force directly to the enamel-bracket interface at a speed of 0.5 mm/min. The groups were compared using two-way analysis of variance. Mean results and standard deviation for the groups were: group 1 = 11.60 +/- 2.65 Mpa, group 2 = 9.79 +/- 2.71 Mpa, group 3 = 10.75 +/- 2.67 Mpa, and group 4 = 10.31+/- 2.70 Mpa. No difference was observed between the conventional etching and primer or SEP (P = .948). However, significant differences in bond strength were present between the uncoated and precoated brackets (P = .032). Considering the values required to withstand normal orthodontic forces (8-9 Mpa), it could be concluded that the SEP combined with adhesive precoated brackets showed adequate shear bond strength and may be suitable for clinical use.

Influence of Er:YAG laser irradiation distance on the bond strength of a restorative system to enamel.

OBJECTIVES: The aim of the present study was to investigate in vitro the effect of Er:YAG laser on bonding to enamel, varying the irradiation distance. METHOD: Tensile bond strength of an adhesive restorative system to non-irradiated and irradiated enamel surfaces was evaluated. Thirty caries-free human third molars were sectioned in mesio-distal direction and embedded in acrylic resin. Enamel was flattened, and a 3-mm-diameter bonding area was demarcated. Specimens were randomly assigned into six groups: groups I-V were treated with the Er:YAG laser (80 mJ/2 Hz), varying the irradiation distance (11, 12 mm-focused, 14, 16 and 17 mm, respectively), followed by 35% phosphoric acid etching. Control group (VI) received treatment with phosphoric acid alone. Single Bond adhesive system was applied on the conditioned enamel, and composite resin cones, bonded to enamel, were fabricated with Z250. After storage, samples were tested in tensile to failure (50 kgf and 0.5 mm/min). RESULTS: Means in MPa were: I-9.67 (+/-3.44); II-13.29 (+/-2.65); III-13.33 (+/-2.22); IV-14.87 (+/-3.58); V-16.43 (+/-4.52); VI-22.90 (+/-3.03). ANOVA and Tukey test revealed statistically significant decrease of bond strength in group I (P < 0.05). Groups II-IV presented similar results, as did groups IV and V. Control group (VI) yielded the best overall performance (P < 0.05). CONCLUSION: Er:YAG laser irradiation adversely affected adhesion to enamel. However, bond strength was influenced by the irradiation distance, thus being stronger with the increase of distance to the target tissue.