Effect of temperature and storage time on dental bleaching effectiveness.

OBJECTIVE: To evaluate the effect of storage time and temperature on the effectiveness of bleaching agents. METHODS: Enamel slabs were randomly allocated according to the concentration of carbamide peroxide (CP): 10% (CP10) and 16% (CP16). Shade evaluations were conducted at baseline and then after 3 and 12 months of storage at 3 different temperatures: 10°C (±2°C), 25°C (±2°C), and 35°C (±2°C). Objective color evaluation was performed (spectrophotometer CIEL*a*b* system and CIEDE2000) to calculate the color change (ΔE00 ). Subjective evaluation was performed using the VITA classical shade guide followed by shade variation (ΔS). RESULTS: The bleaching effect of different CP concentrations (10% and 16%) at baseline showed no differences with regard to objective (ΔE00 ) and subjective parameters (ΔS) (P > .05). No differences were observed between CP concentrations stored for the same length of time and at the same temperature for either parameter (P > .05). In terms of objective measurement (ΔE00 ), a reduction in the bleaching effect was shown for both CP concentrations (10% and 16%) when stored for 12 months at 35°C, and compared with the baseline (P < .05). As regards the subjective parameters (ΔS), after 12 months, both CP concentrations (10% and 16%) stored at 35°C showed a decrease in bleaching capacity compared to baseline (P < .05). CP10 and CP16 stored at 10°C and 25°C did not suffer any loss in bleaching ability, even after 12 months (P > .05). CONCLUSIONS: The storage of bleaching agents for long periods at high temperatures can reduce the bleaching effectiveness of CP at 10% and 16%. CLINICAL SIGNIFICANCE: Clinicians must be made aware that they should store their bleaching products under proper temperature conditions and use them within an appropriate time frame; otherwise, the bleaching effect could be lost.

Vital Pulp Therapies in Clinical Practice: Findings from a Survey with Dentist in Southern Brazil

Studies based on dentists' clinical practice possess vital relevance to understand factors leading the clinicians to choose by a specific technique over another. This study investigated which clinical conduct therapies are adopted by dentists in front of deep caries. Was evaluated how the place of work, post-graduate training and years since complete graduation influenced their decisions. A cross-sectional study was performed using a self-applied questionnaire with dentists (n=276) in Southern Brazil. Information regarding post-graduation training (specialization, master's or PhD), clinical experience (years since completing graduation) and place of work were investigated. The information regarding pulp vital therapies (materials for direct pulp capping; techniques for caries removal in deep cavities and strategies for indirect pulp capping) were collected by specific questions. Data were submitted to descriptive analysis and Exact Fischer Test. Response rate was 68% (187). The majority of dentists selected the calcium hydroxide (CH) as first material for direct (86.3%) and indirect (80.3%) pulp protection. Partial caries removal was reported by 61.9% of dentists. Less experienced clinical dentists choose partial caries removal more frequently (p=0.009), if compared with dentists graduated 10 years and up ago. The use of MTA was more common among professionals working at academic environment. Besides, MTA was not mentioned by professionals working exclusively in the public health service (p=0.003). In conclusion, the time since graduation influenced the clinical conduct related to caries removal. The choice of liner materials was influenced by dentists' workplace.

Resumo Estudos baseados na prática clínica de dentistas possuem relevância vital para o entendimento dos fatores que influenciam os clínicos na escolha de uma técnica específica em detrimento de outra. Este estudo investigou quais condutas clínicas são adotadas por dentistas frente a lesões profundas de cárie. Foi avaliado como o local de trabalho, curso de pós-graduação e tempo desde a graduação influenciaram suas decisões clínicas. Foi conduzido um estudo transversal utilizando questionários auto- aplicados à dentistas no sul do Brasil (n=276). Informações relacionadas a educação continuada (especialização, mestrado ou doutorado), experiência clínica (anos desde a graduação) e local de trabalho foram investigadas. As informações sobre terapias vitais da polpa (materiais para capeamento pulpar direto, técnicas para remoção de carie em cavidades profundas e estratégias para capeamento pulpar indireto) foram coletadas por meio de perguntas específicas. Os dados foram submetidos à análise descritiva e teste exato de Fisher. A taxa de resposta foi de 68% (187). A maioria dos dentistas selecionam o hidróxido de cálcio (HC) como primeiro material para proteção pulpar direta (86,3%) e indireta (80,3%). Remoção parcial de tecido cariado foi relatado por 61,9% dos clínicos. Dentistas com menor experiência clínica optaram pela remoção parcial de tecido cariado com mais frequência (p=0,009), quando comparados a dentistas graduados há mais de 10 anos. O uso do MTA foi mais comum entre os profissionais que trabalham em ambiente acadêmico. Além disso, o MTA não foi mencionado pelos profissionais que trabalham exclusivamente no serviço público de saúde (p=0,003). O tempo desde a graduação influenciou a conduta clínica relacionada à remoção de cárie. A escolha de materiais para proteção pulpar foi influenciada pelo local de trabalho dos dentistas.

Vital Pulp Therapies in Clinical Practice: Findings from a Survey with Dentist in Southern Brazil.

Studies based on dentists' clinical practice possess vital relevance to understand factors leading the clinicians to choose by a specific technique over another. This study investigated which clinical conduct therapies are adopted by dentists in front of deep caries. Was evaluated how the place of work, post-graduate training and years since complete graduation influenced their decisions. A cross-sectional study was performed using a self-applied questionnaire with dentists (n=276) in Southern Brazil. Information regarding post-graduation training (specialization, master's or PhD), clinical experience (years since completing graduation) and place of work were investigated. The information regarding pulp vital therapies (materials for direct pulp capping; techniques for caries removal in deep cavities and strategies for indirect pulp capping) were collected by specific questions. Data were submitted to descriptive analysis and Exact Fischer Test. Response rate was 68% (187). The majority of dentists selected the calcium hydroxide (CH) as first material for direct (86.3%) and indirect (80.3%) pulp protection. Partial caries removal was reported by 61.9% of dentists. Less experienced clinical dentists choose partial caries removal more frequently (p=0.009), if compared with dentists graduated 10 years and up ago. The use of MTA was more common among professionals working at academic environment. Besides, MTA was not mentioned by professionals working exclusively in the public health service (p=0.003). In conclusion, the time since graduation influenced the clinical conduct related to caries removal. The choice of liner materials was influenced by dentists' workplace.

Tooth erosion and dental caries in schoolchildren: is there a relationship between them?

AIM: To identify a possible association between the occurrence of dental caries and tooth erosion and to correlate the dietary factor with an increased risk of dental caries. METHODS: A cross-sectional study in a multistage random sample of 1,211, 8 to 12-years-old Brazilian schoolchildren in private and public schools was conducted in Pelotas, Brazil. The prevalence of dental caries and tooth erosion was assessed. Dietary habits data were collected by a structured questionnaire. Data were analyzed using Poisson regression model taking into account the cluster sample (Prevalence ratio - PR; 95% Confidence Interval - CI). RESULTS: The prevalence of dental caries and tooth erosion was 32.4% (95% CI: 30.0; 35.2) and 25.0% (95% CI: 23.4; 29.0), respectively. Most children had high consumption of sweets (65%). Consumption of fruits, such as oranges (31%), strawberries (23.6%), pineapple (12%), and natural fruit juices (oranges, lemon) was low. Soft drinks consumption, 3 or more times a week was observed in 40% of the children. CONCLUSIONS: Dental caries was not statistically associated with tooth erosion. The consumption of acidic fruits/drinks was not associated with dental caries. Dental caries and dental erosion were not associated with each other and with acidic fruits or drinks consumption.

Changes in oral health related quality of life after dental bleaching in a double-blind randomized clinical trial.

OBJECTIVES: This study aimed to assess changes in oral health-related quality of life (OHRQoL) in individuals enroled in a double-blind randomized clinical trial conducted to evaluate the efficacy and safety of two carbamide peroxide concentrations used in at-home vital bleaching in the city of Pelotas, Southern Brazil. METHODS: Ninety-two volunteers with a shade mean of C1 or darker for the six maxillary anterior teeth were randomized into two balanced groups (n=46) according to bleaching agent concentration: 10% or 16% carbamide peroxide. The patients were instructed to use the whitening agent in a tray for 2h once a day for three weeks. To assess changes in OHRQoL, participants completed the oral impact on daily performance (OIDP) at the start and one week after the completion of treatment. Because there was no difference with regard to whitening effect or tooth sensitivity during or after treatment the two groups were merged for the analyses of the current article. Before-and-after changes in OIDP scores were assessed by chi-square and McNemar tests (p<0.05). RESULTS: Mean pre- and post-treatment OIDP scores varied from 0.42 to 0.60. When the frequency of impacts for different activities were compared, there was an increase in difficulty in cleaning teeth (p=0.02) and a significant reduction in smiling and showing teeth with embarrassment (p=0.03). Regarding the symptoms and main oral conditions that generated impact, there was higher number of participants reporting pain (p=0.05) after treatment. In opposite, significant decrease was observed in individuals reporting being unhappy with their appearance (p=0.03). On the contrary, it was showed a decrease in impacts resulting from dental colour was observed after bleaching (p=0.03). CONCLUSION: Quality of life is complex and encompasses different domains. Although positive impact of the dental bleaching was detected, with patients showing more their teeth without embarrassment, difficult in dental hygiene and pain resulting from the treatment were also reported, and this can negatively impact daily performances. Dentists must consider these aspects when performing aesthetics procedures.

Radiopacity of restorative composites by conventional radiograph and digital images with different resolutions.

PURPOSE: This study was performed to evaluate and compare the radiopacity of dentin, enamel, and 8 restorative composites on conventional radiograph and digital images with different resolutions. MATERIALS AND METHODS: Specimens were fabricated from 8 materials and human molars were longitudinally sectioned 1.0 mm thick to include both enamel and dentin. The specimens and tooth sections were imaged by conventional radiograph using #4 sized intraoral film and digital images were taken in high speed and high resolution modes using a phosphor storage plate. Densitometric evaluation of the enamel, dentin, restorative materials, a lead sheet, and an aluminum step wedge was performed on the radiographic images. For the evaluation, the Al equivalent (mm) for each material was calculated. The data were analyzed using one-way ANOVA and Tukey's test (p<0.05), considering the material factor and then the radiographic method factor, individually. RESULTS: The high speed mode allowed the highest radiopacity, while the high resolution mode generated the lowest values. Furthermore, the high resolution mode was the most efficient method for radiographic differentiation between restorative composites and dentin. The conventional radiograph was the most effective in enabling differentiation between enamel and composites. The high speed mode was the least effective in enabling radiographic differentiation between the dental tissues and restorative composites. CONCLUSION: The high speed mode of digital imaging was not effective for differentiation between enamel and composites. This made it less effective than the high resolution mode and conventional radiographs. All of the composites evaluated showed radiopacity values that fit the ISO 4049 recommendations.

Novel experimental cements for use on the dentin-pulp complex.

This aim of this study was to evaluate the physicochemical and biological properties of novel experimental cements (Hybrid, Paste and Resin) based on synergistic combinations of existing materials, including pH, diametral tensile strength (DTS) and cytotoxicity comparing them with mineral trioxide aggregate (MTA - Angelus®) and a glass ionomer cement (GIC) developed at our laboratory. For the physicochemical and biological tests, specimens with standard dimensions were produced. pH measurements were performed with digital pH meter at the following time intervals: 3, 24, 48 and 72 h. For the DTS test, cylindrical specimens were subjected to compressive load until fracture. The MTT assay was performed for cytotoxicity evaluation. Data were analyzed by ANOVA and Tukey's test (α=0.05). Paste group showed pH values similar to MTA, and Hybrid group presented pH values similar to GIC (p>0.05). The tested materials showed pH values ranging from alkaline to near neutrality at the evaluated times. MTA and GIC showed similar DTS values. The lowest and highest DTS values were seen in the Paste and Resin groups, respectively (p<0.05). Cell viability for MTA and experimental Hybrid, Paste and Resin groups was 49%, 93%, 90% and 86%, respectively, when compared with the control group. The photo-cured experimental resin cement showed similar or superior performance compared with the current commercial or other tested experimental materials.

Elements of implant-supported rehabilitation planning in patients with bruxism.

The rehabilitation of partial or completely edentulous patients with implant-supported prostheses has been widely used, achieving high success rates. However, many studies consider the presence of bruxism as a contraindication for this treatment modality. The purpose of this study was to revise the literature and identify risk factors in implant-supported rehabilitation planning in subjects with bruxism. Available literature was searched through Medline, with no time limit, including only studies in English. Topics discussed were etiology of bruxism and its implications on dental implants, biomechanical considerations regarding the overload on dental implants, and methods to prevent the occurrence of overloads in implant-supported prostheses. The rehabilitation of bruxers using implant-supported prostheses, using implants with adequate length and diameter, as well as proper positioning seems to be a reliable treatment, with reduced risks of failure. Bruxism control through the use of a nightguard by rigid occlusal stabilization appliance relieved in the region of implants is highly indicated. Although it is clear that implant-supported rehabilitation of patients with bruxism requires adequate planning and follow-up, well-designed randomized controlled trials are needed to provide reliable evidence on the long-term success of this treatment modality.

Novel experimental cements for use on the dentin-pulp complex

This aim of this study was to evaluate the physicochemical and biological properties of novel experimental cements (Hybrid, Paste and Resin) based on synergistic combinations of existing materials, including pH, diametral tensile strength (DTS) and cytotoxicity comparing them with mineral trioxide aggregate (MTA - Angelus®) and a glass ionomer cement (GIC) developed at our laboratory. For the physicochemical and biological tests, specimens with standard dimensions were produced. pH measurements were performed with digital pH meter at the following time intervals: 3, 24, 48 and 72 h. For the DTS test, cylindrical specimens were subjected to compressive load until fracture. The MTT assay was performed for cytotoxicity evaluation. Data were analyzed by ANOVA and Tukey's test (α=0.05). Paste group showed pH values similar to MTA, and Hybrid group presented pH values similar to GIC (p>0.05). The tested materials showed pH values ranging from alkaline to near neutrality at the evaluated times. MTA and GIC showed similar DTS values. The lowest and highest DTS values were seen in the Paste and Resin groups, respectively (p<0.05). Cell viability for MTA and experimental Hybrid, Paste and Resin groups was 49%, 93%, 90% and 86%, respectively, when compared with the control group. The photo-cured experimental resin cement showed similar or superior performance compared with the current commercial or other tested experimental materials.

O objetivo deste estudo foi avaliar propriedades físico-químicas e biológicas de novos cimentos experimentais (Híbrido, Pasta e Resinoso) baseado na combinação sinérgica de materiais existentes, incluindo pH, resistência à tração diametral (RTD) e citotoxidade, comparando-os ao MTA (Angelus®) e a um cimento de ionômero de vidro (CIV) desenvolvido em nosso laboratório. Para a realização dos testes físico-mecânico e biológico, foram confeccionados espécimes com dimensões padrão. O teste de pH foi realizado por meio de pH-metro digital nos tempos: 3, 24, 48 e 72 h. Para o teste de RTD, espécimes cilíndricos foram submetidos a carga compressiva até sua fratura. Para avaliação da citotoxidade, utilizou-se o teste MTT. Os dados foram analisados utilizando ANOVA e teste de Tukey (α=0,05). O grupo Pasta apresentou valores de pH semelhantes ao MTA, assim como o grupo Híbrido seguiu os parâmetros do CIV (p>0,05). Todos os materiais apresentaram valores de pH alcalinos ou próximosà neutralidade nos tempos avaliados. MTA e CIV apresentaram valores de RTD similares. Os menores e maiores valores observados foram do grupo Pasta e Resinoso, respectivamente (p<0,05). A viabilidade celular para os grupos MTA, Híbrido, Pasta, Resinoso, quando comparados ao grupo controle foi de: 49, 93, 90 e 86%, respectivamente. O cimento experimental Resinoso apresentou desempenho similar ou superior aos materiais comerciais e experimentais avaliados.

Erosion and abrasion on dental structures undergoing at-home bleaching.

This review investigates erosion and abrasion in dental structures undergoing at- home bleaching. Dental erosion is a multifactorial condition that may be idiopathic or caused by a known acid source. Some bleaching agents have a pH lower than the critical level, which can cause changes in the enamel mineral content. Investigations have shown that at-home tooth bleaching with low concentrations of hydrogen or carbamide peroxide have no significant damaging effects on enamel and dentin surface properties. Most studies where erosion was observed were in vitro. Even though the treatment may cause side effects like sensitivity and gingival irritation, these usually disappear at the end of treatment. Considering the literature reviewed, we conclude that tooth bleaching agents based on hydrogen or carbamide peroxide have no clinically significant influence on enamel/dentin mineral loss caused by erosion or abrasion. Furthermore, the treatment is tolerable and safe, and any adverse effects can be easily reversed and controlled.

Condições de saúde bucal, acesso aos serviços odontológicos e autopercepção de saúde bucal em escolares de 12 anos / Oral health status, access to dental services and self-perception of oral health in 12 years Old schoolchildren

Objetivo: Avaliar a condição de saúde bucal em escolares de 12 anos, na cidade de João Pessoa-PB, e identificar informações sobre acesso aos serviços odontológicos e autopercepção em saúde bucal. Método: Do universo composto por todos os indivíduos de 12 anos matriculados em estabelecimentos de ensino, a casuística foi constituída por 286 crianças que foram avaliadas por examinadores previamente calibrados. As crianças responderam a uma entrevista estruturada com variáveis referentes ao acesso aos serviços odontológicos e a autopercepção em saúde bucal. Os dados foram analisados descritivamente. Resultados: O CPO-D médio foi de 3,62 (DP=±2,95), constatando-se que 35,09% dos escolares se apresentavam livres de cárie. Dentre as necessidades de tratamento, restaurações de uma superfície foram as mais freqüentes (5,75%). A presença de sangramento gengival foi detectada em 8,86% dos sextantes examinados nos escolares e 8,22% apresentavam cálculo. Quanto às anormalidades dento-faciais, 38,14% das crianças necessitavam de algum tipo de intervenção clínica e apenas 0,35% delas apresentou fluorose dentária (Grau 2 - muito leve). Dos 286 escolares, 94,05% foram ao dentista ao menos uma vez na vida e 53,5% relataram uma situação de saúde bucal péssima, ruim ou regular. Conclusão: a prevalência de cárie dentária para escolares de 12 anos é moderada e a necessidade de tratamento se caracteriza especialmente por procedimentos clínicos de baixa complexidade e de fácil resolução. É expressivo o número de escolares que apresentam sinais de alteração gengival, constatou-se uma elevada prevalência de má oclusão e baixa ocorrência de fluorose dentária na população estudada. Os serviços odontológicos se mostraram disponíveis a um número considerável de escolares de 12 anos, que, em sua maioria, não demonstrou possuir uma boa autopercepção de sua saúde bucal.

Objective: to evaluate the oral health status at the population of 12 years of the city of Joao Pessoa-PB and to identify at the sample information about the access to dental services and self-perception in oral health. Method: From the universe composed by all subjects with 12 years old enrolled in educational institutions, the sample consisted of 286 children who were evaluated by examiners previously calibrated. Children answered to a structured interview with variables related to access to dental services and self-perception in oral health. The findings were analyzed of descriptive form. Results: The index DMFT founded was 3.62 (SD=±2.95), noting that 35,09% of the students presented caries free. Among the needs for treatment, restorations of a surface were the most frequent (5.75%). In relation to the DMFT, carious component had the highest percentage (59.86%), followed by obturated (37.52%) and lost (2.61%). The presence of gingival bleeding was detected in 8.86% of sextants examined in scholars and 8.22% had calculus. About the facial abnormalities, 38.14% of the children needed some type of clinical intervention e only 0.35% showed dental fluorosis (grade 2 - very slight). From the 286 interviewed students, 94.05% went to the dentist at least once in their lives and 53.5% reported a situation of poor, bad or regular oral health. Conclusion: the prevalence of caries to scholars of 12 years is moderate and the treatment need is characterized especially by clinical procedures of low complexity and easy resolution. It is expressive the number of scholars who shows signs of gingival alterations, noting a high prevalence of malocclusion and low occurrence of dental fluorosis in the sampled population. Access to dental services was available to a large number of schoolchildren with 12 years, that, in their majority, have not shown a good self-perception of oral health.

Características físico-químicas da dieta líquida cafeinada / Physicochemical characteristics of the caffeinated liquid diet

Objetivo: Estudar as características físico-químicas de bebidas líquidas cafeinadas comercializados na cidade de João Pessoa, PB.Método: Produtos utilizados: Nescafé®, Santa Clara®, São Brás®, Pilão® (cafés); Dr. Oetker®, Madrugada®, Leão® (chás pretos); Coca Cola® , Coca Cola light lemon®, Coca Cola zero®, Coca Cola light® (refrigerantes de cola). O preparo das soluções foi convencionado a uma proporção de 0,8g do pó, medido em balança digital, no caso do café, e um sachê para o chá, utilizando 50ml de água destilada fervida para ambos. Os refrigerantes foram analisados naturalmente, após sua abertura. Utilizando-se pHmetro digital foram feitas as aferições dos valores de pH, logo após o preparo das amostras, sendo obtida a média das três medições para cada produto analisado. Procedeu-se a medição da ATT utilizando 5ml de cada produto, adicionando-se 100ml de água destilada e deionizada acrescida de 5 gotas de indicador fenoftale??na a 1%. Adicionou-se NaOH a 0,01 N à solução até atingir o ponto de viragem. A medição do Brix foi feita com auxílio de um refratômetro com faixa de leitura de ºBrix de 0~32% e precisão de 0,2, utilizando-se aproximadamente 2 gotas de cada produto. Os dados foram analisados descritivamente.Resultados: Os valores de pH, acidez e sólidos solúveis, para os cafés: variaram, respectivamente de 4,69 a 4,78, 0,07% a 0,09%, 1,0 a 2,0 ºBrix; para os chás: foram respectivamente de 4,81 a 4,93, 0,06% a 0,07%, 0,0 ºBrix; e para os refrigerantes obteve-se os respectivos resultados: de 2,33 a 2,83, 0,23% a 0,49%, 0,0 a 0,7 ºBrix.Conclusão: O pH de algumas bebidas cafeinadas é baixo, confirmado pelo valor encontrado para acidez, além disso, o açúcar presente nestas amostras contribui para agravar o potencial cariogênico e erosivo das mesmas.