Academics knowledge about tooth bleaching: technical and ethical issues / Conhecimento de acadêmicos acerca do clareamento dental: questões técnicas e éticas

ABSTRACT Objective: The aim of this study was to evaluate the level of knowledge of UFES dental students about home bleaching treatment. Methods: As a methodology, a descriptive and cross-sectional study was carried out through the application of practice to 109 students, containing questions about home tooth whitening, technical care and possible complications of the treatment. Data were tabulated and submitted to descriptive statistics. Results: Of the total number of students, 88.99% said they knew the factors that limit or contraindicate the bleaching treatment, 16.51% of students recognize hydrogen peroxide as a possible inducer of oral cancer, 30.27% of the students had their teeth whitened inside the University, 44.03% had their teeth whitened outside the University without professional supervision. In addition, 56.88% believe anamnesis and clinical examination are necessary before the bleaching treatment. Conclusion: It is concluded that students have limited knowledge about certain points of at-home tooth whitening. Students know the risk factors of bleaching treatment, except regarding hydrogen peroxide being a possible inducer of oral cancer. It can be inferred that academics highlight the importance of associating the clinical examination with the patient's anamnesis before performing the bleaching treatment. Most students have had their teeth whitened outside the University, which calls attention to reinforce knowledge about the ethical issues of the profession.

RESUMO Objetivo: O objetivo deste estudo foi avaliar o nível de conhecimento dos acadêmicos de odontologia da UFES sobre o tratamento clareador caseiro. Métodos: Como metodologia, foi realizado um estudo descritivo e transversal por meio da aplicação de questionário a 109 estudantes contendo perguntas sobre o clareamento dental caseiro, cuidados técnicos e possíveis riscos do tratamento. Os dados foram tabulados e submetudos à estatística descritiva. Resultados: Do total de estudantes, 88,99% disse conhecer os fatores que limitam ou contraindicam o tratamento clareador; 16,51% dos estudantes reconhecem o peróxido de hidrogênio como possível indutor de câncer bucal; 30,27% dos estudantes realizaram o clareamento dental dentro da Universidade, 44,03% realizaram o clareamento dental fora da Universidade sem supervisão profissional. Além disso, 56,88% acreditam que são necessários anamnese e exame clínico antes de realizar o tratamento clareador. Conclusão: Conclui-se que os alunos têm conhecimento limitado sobre determinados pontos do clareamento dental caseiro. Os estudantes conhecem os fatores de risco do tratamento clareador, exceto a respeito do peróxido de hidrogênio ser um possível indutor de câncer bucal. Pode-se inferir que os acadêmicos relevam a importância da associação do exame clínico com a anamnese do paciente antes de se realizar o tratamento clareador. A maioria dos estudantes tem realizado o clareamento dental fora da Universidade, o que chama atenção para reforçar o conhecimento sobre as questões éticas da profissão.

Effects of polyvinyl chloride film and oxygen-blocking gel on irradiance and depth of cure.

This study aimed to analyze the effects of polyvinyl chloride (PVC) film and oxygen-blocking gel (OBG) on the irradiance from an LED source and the depth of cure of a composite resin. Irradiance was measured with a curing radiometer, and curing depth was evaluated according to the methods described by the International Organization for Standardization (ISO 4049). Twelve experimental conditions were investigated in a 3 × 4 factorial design (n = 5 specimens per condition): no PVC film at the tip of the device, fitted PVC film, or misfit PVC film; and no OBG or a 1-, 2-, or 3-mm-thick layer of OBG. The data were analyzed using analysis of variance and Tukey tests (P < 0.05), and a linear regression test was performed between the variables (P < 0.05). The analyses showed that the variables under study influenced the irradiance (P < 0.05) but not the curing depth (P > 0.05). The 3 groups that did not have the PVC film and either did not have the OBG or had the OBG in a thickness of 1 or 2 mm were not significantly different from each other (P > 0.05) but presented the highest irradiance values among all the groups (P < 0.05). The use of the misfit PVC film with a 3-mm layer of OBG led to the lowest irradiance values (P < 0.05). The variables did not influence each other (P > 0.05). The results of this study indicated that the presence of PVC film, especially misfit film, reduced the irradiance. In addition, the greater the thickness of the OBG, the lower the irradiance. None of the PVC film barrier conditions or OBG thicknesses had an effect on the depth of cure.

The Use of Resinous Infiltrants for the Management of Incipient Carious Lesions: a Literature Review / Uso de Infiltrantes Resinosos para Tratamento de Lesões Cariosas Incipientes: uma Revisão da Literatura

The objective of this work was to analyze scientific evidence from a literature review pertaining to the effectiveness of resinous infiltrants for minimally invasive treatment of incipient carious lesions. Studies published between 2002 and 2019 were queried from the following databases: Capes, PubMed, Medline, BBO, Lilacs and SciELO. The search keywords included "Dental Caries", "Tooth Remineralization", "Dental Leakage". Most of the studies found resin-infiltrating treatment to be a viable option for the minimally invasive treatment of incipient carious lesions; this treatment was able to fulfill the primary expected effects: inhibition of carious progression and the lesions esthetic improvement. However, some issues need to be clarified to improve the safety of this treatment because it can be recommended in clinical practice. Inconclusion, the use of resinous infiltrants has been reported as promising for the treatment of incipient carious lesions. However, there is a need for long-term studies to confirm the effectiveness of this treatment to determine its applicability for clinical use. (AU)

O objetivo desse trabalho foi analisar evidências científicas, por meio de uma revisão de literatura, sobre a eficácia do uso de infiltrantes resinosos para o tratamento minimamente invasivo de lesões cariosas incipientes. A seleção do material literário utilizado foi realizada por pesquisa sobre o tema nas bases de dados: portal de periódicos Capes, PubMed, Medline, BBO, Lilacs e SciELO, abrangendo prioritariamente, o período de 2002 a 2019. Para busca nas bases de dados foram utilizadas palavras-chave como "Cárie Dentária", "Remineralização Dentária", "Infiltração Dentária", assim como suas correspondentes na língua inglesa. A maioria dos estudos encontrados aponta o tratamento infiltrante resinoso como uma opção viável para o tratamento minimamente invasivo de lesões cariosas incipien tes sendo capaz de cumprir os principais efeitos esperados: inibição da progressão cariosa e melhoria estética das lesões. Entretanto, alguns impasses necessitam ser esclarecidos para que o tratamento seja recomendado com mais segurança na prática clínica. Conclui-se que o uso de infiltrantes resinosos tem sido relatado como promissor para o tratamento de lesões cariosas incipientes, contudo há necessidade de novas pesquisas e estudos a longo prazo para confirmar sua eficácia em todos aspectos desejáveis para seu uso clínico. (AU)

Critérios clínicos para decisão entre substituição ou reparo de restaurações em resina composta - revisão de literatura / Clinical criteria for decisions between the replacement and repair of restoration in composite resin restorationsliterature review

Objetivo: Este estudo objetivou analisar os critérios USPHS e USPHS modificados e oferecer subsídios para a decisão clínica entre o reparo e a substituição das restaurações em resina composta. Material e Métodos: Utilizou-se um levantamento bibliográfico através do Portal de Periódicos CAPES, PubMed, Cochrane e Medline utilizando as seguintes palavras-chave: USPHS, avaliação clínica, resina composta, restauração dental permanente. A partir dessa pesquisa, foram selecionados trabalhos publicados entre 2000 e 2016. Resultados: Os estudos avaliados indicaram que os critérios mais prevalentes nas restaurações insatisfatórias são "cáries secundárias" e "perda da forma anatômica". Além disso, a maioria dos estudos avaliados indica o reparo de restaurações com falhas pequenas e localizadas como estratégia para o aumento da longevidade das restaurações em resina composta. Conclusão: Os critérios USPHS auxiliam na correta decisão clínica entre substituição ou reparo de restaurações em resina composta. O reparo de compósitos é uma alternativa que deve ser realizada sempre que possível.

Objective: This study aimed to analyze the United States Public Health Service (USPHS) and USPHS modified criteria and offer subsidies for clinical decisions between the repair and replacement of composite resin restorations. Material and Methods: We have selected, through a literature search, papers published between 2000 and 2016 on CAPES Journal Portal, PubMed, Cochrane, and Medline. The keywords used were as follows: USPHS, clinical trial, composite resin, and permanent dental restoration. Results: The evaluated studies indicated that the most prevalent criteria on unsatisfactory restorations are the "secondary caries" and "loss of anatomical shape." In addition, majority of the evaluated studies indicate the repair of restorations with minor and localized failures as a strategy to increase the longevity of composite resin restorations. Conclusion: The USPHS criteria assist in the correct clinical decision between the replacement and repair of composite resin restorations. Repairing the restoration is a clinical alternative that should be performed whenever it is possible.

The effect of preheating and opacity on the sorption and solubility of a composite resin.

This study evaluated the influence of material opacity and preheating on the sorption and solubility of a composite resin material. A commercially available composite resin and an 8 × 2-mm circular metallic matrix were used to fabricate a total of 60 specimens in 6 shades, of which 3 had conventional opacity (CA2, CA3, and CA3.5) and 3 were opaque (OA2, OA3, and OA3.5). Specimens were prepared at a room temperature of 25°C or preheated to 60°C (n = 5 per shade at each temperature). The specimens were weighed 3 times: M1, dried for 24 hours at 37°C; M2, stored for 7 days in 75% ethanol at 37°C; and M3, dried for an additional 24 hours at 37°C. The weights were used to calculate the sorption and solubility of the composite resin and were analyzed using 2-way analysis of variance and Tukey tests (α = 5%). Composite resin specimens heated at 60°C yielded lower values of sorption and solubility than did specimens prepared at 25°C (P < 0.05). The sorption and solubility of conventional and opaque composite shades were found to be similar (P > 0.05), except for shade CA2, which presented a greater mean solubility value than OA2 (P = 0.004). Therefore, preheating was beneficial, as it lowered both the sorption and solubility of the evaluated composite resin, but opacity had little effect on these properties.

Molar incisor hypomineralization: an aesthetic conservative restorative approach / Hipomineralização molar-incisivo: uma abordagem restauradora estética conservadora

ABSTRACT The aim this study is to present a clinical case of conservative aesthetic restorative treatment of teeth 11 and 21 in a patient diagnosed with molar incisor hypomineralization. An 18-year-old female patient came to the Outpatient Restorative Dentistry Clinic at the Federal University of Espírito Santo, complaining mainly of not feeling comfortable with a color change in her anterior teeth. Molar incisor hypomineralization was diagnosed in molars and incisors and the negative psychosocial implications for the aesthetics involved were noticed. Due to factors such as age, financial viability, technical facility and low degree of severity, we opted for maximum preservation of the healthy tooth structure, through minimal surgical intervention to remove the irregular enamel only and subsequently restore the teeth involved (11 and 21) with resin composite. For the patient, this conservative procedure restored function and aesthetics, and thereby improved her emotional and social behavior. Conservative restorations can provide real solutions, especially in cases of molar incisor hypomineralization in anterior teeth where the patient's psychological state should always be considered. An appropriate assessment of the dental substrate and a careful restorative technique are necessary for success in terms of aesthetics and function and can quickly promote the patient's well-being.

RESUMO O objetivo do trabalho é apresentar um caso clínico de tratamento restaurador estético conservador de dentes anteriores (11 e 21) em paciente com diagnóstico de hipomineralização-molar incisivo. A paciente do sexo feminino, 18 anos, procurou o ambulatório de Odontologia Restauradora Clínica da Universidade Federal do Espírito Santo, com queixa principal de incômodo com a alteração de cor dos dentes anteriores. Houve o diagnóstico de hipomineralização-molar incisivo em dentes molares e incisvos, percebendo-se uma implicação psicossocial negativa pela estética envolvida. Devido aos fatores idade, viabilidade financeira, facilidade técnica e baixo grau de severidade da lesão, optou-se por privilegiar uma maior preservação possível de estrutura dentária sadia, sendo realizada mínima intervenção operatória, removendo-se somente o esmalte irregular com subsequente restauração com resina composta nos elementos envolvidos (11 e 21). Este procedimento restaurador conservador foi capaz de devolver à paciente função e estética, melhorando seu comportamento emocional e social. As restaurações estéticas conservadoras podem ser altamente resolutivas, principalmente em casos de hipomineralização-molar incisivo em dentes anteriores, onde o fator psicológico do paciente deve sempre ser considerado. Uma avaliação adequada do substrato dentário e criteriosa técnica restauradora são necessárias para o sucesso no âmbito estético-funcional, sendo capaz de restabelecer rapidamente o bem-estar do paciente.

56-month clinical performance of Class I and II resin composite restorations.

OBJECTIVE: This study evaluated the 56-month clinical performance of Class I and II resin composite restorations. Filtek P60 was compared with Filtek Z250, which are both indicated for posterior restorations but differ in terms of handling characteristics. The null hypothesis tested was that there is no difference in the clinical performance of the two resin composites in posterior teeth. MATERIAL AND METHODS: Thirty-three patients were treated by the same operator, who prepared 48 Class I and 42 Class II cavities, which were restored with Single Bond/Filtek Z250 or Single Bond/Filtek P60 restorative systems. Restorations were evaluated by two independent examiners at baseline and after 56 months, using the modified USPHS criteria. Data were analyzed statistically using Chi-square and Fisher's Exact tests (a=0.05). RESULTS: After 56 months, 25 patients (31 Class I and 36 Class II) were analyzed. A 3% failure rate occurred due to secondary caries and excessive loss of anatomic form for P60. For both restorative systems, there were no significant differences in secondary caries and postoperative sensitivity. However, significant changes were observed with respect to anatomic form, marginal discoloration, and marginal adaptation. Significant decreases in surface texture were observed exclusively for the Z250 restorations. CONCLUSIONS: Both restorative systems can be used for posterior restorations and can be expected to perform well in the oral environment.

56-month clinical performance of Class I and II resin composite restorations

OBJECTIVE: This study evaluated the 56-month clinical performance of Class I and II resin composite restorations. Filtek P60 was compared with Filtek Z250, which are both indicated for posterior restorations but differ in terms of handling characteristics. The null hypothesis tested was that there is no difference in the clinical performance of the two resin composites in posterior teeth. MATERIAL AND METHODS: Thirty-three patients were treated by the same operator, who prepared 48 Class I and 42 Class II cavities, which were restored with Single Bond/Filtek Z250 or Single Bond/Filtek P60 restorative systems. Restorations were evaluated by two independent examiners at baseline and after 56 months, using the modified USPHS criteria. Data were analyzed statistically using Chi-square and Fisher's Exact tests (a=0.05). RESULTS: After 56 months, 25 patients (31 Class I and 36 Class II) were analyzed. A 3% failure rate occurred due to secondary caries and excessive loss of anatomic form for P60. For both restorative systems, there were no significant differences in secondary caries and postoperative sensitivity. However, significant changes were observed with respect to anatomic form, marginal discoloration, and marginal adaptation. Significant decreases in surface texture were observed exclusively for the Z250 restorations. CONCLUSIONS: Both restorative systems can be used for posterior restorations and can be expected to perform well in the oral environment.

Influence of differently oriented dentin surfaces and the regional variation of specimens on adhesive layer thickness and bond strength.

STATEMENT OF THE PROBLEM: Adhesive systems can spread differently onto a substrate and, consequently, influence bonding. PURPOSE: The purpose of this study was to evaluate the effect of differently oriented dentin surfaces and the regional variation of specimens on adhesive layer thickness and microtensile bond strength (MTBS). MATERIALS AND METHODS: Twenty-four molars were sectioned mesiodistally to expose flat buccal and lingual halves. Standardized drop volumes of adhesive systems (Single Bond [SB] and Prime & Bond 2.1 [PB2.1]) were applied to dentin according to the manufacturer's instructions. Teeth halves were randomly divided into groups: 1A-SB/parallel to gravity; 1B-SB/perpendicular to gravity; 2A-PB2.1/parallel to gravity; and 2B-PB2.1/perpendicular to gravity. The bonded assemblies were stored in 37 degrees C distilled water for 24 hours and then sectioned to obtain dentin sticks (0.8 mm2). The adhesive layer thickness was determined in a light microscope (x200), and after 48 hours the specimens were subjected to MTBS test. Data were analyzed by one-way and two-way analysis of variance and Student-Newman-Keuls tests. RESULTS: Mean values (MPa +/- SD) of MTBS were: 39.1 +/- 12.9 (1A); 32.9 +/- 12.4 (1B); 52.9 +/- 15.2 (2A); and 52.3 +/- 16.5 (2B). The adhesive systems' thicknesses (microm +/- SD) were: 11.2 +/- 2.9 (1A); 18.1 +/- 7.3 (1B); 4.2 +/- 1.8 (2A); and 3.9 +/- 1.3 (2B). No correlation between bond strength and adhesive layer thickness for both SB and PB2.1 (r = -0.224, p = 0.112 and r = 0.099, p = 0.491, respectively) was observed. CONCLUSIONS: The differently oriented dentin surfaces and the regional variation of specimens on the adhesive layer thickness are material-dependent. These variables do not influence the adhesive systems' bond strength to dentin. CLINICAL SIGNIFICANCE Adhesive systems have different viscosities and spread differently onto a substrate, influencing the bond strength and also the adhesive layer thickness. Adhesive thickness does not influence dentin bond strength, but it may impair adequate solvent evaporation, polymer conversion, and may also determine water sorption and adhesive degradation over time. In the literature, many studies have shown that the adhesive layer is a permeable membrane and can fail over time because of its continuous plasticizing and degradation when in contact with water. Therefore, avoiding thick adhesive layers may minimize these problems and provide long-term success for adhesive restorations.

Effect of the number of coats of simplified adhesive systems on microleakage of dentin-bordered composite restorations.

AIM: This study tested the null hypothesis that there is no difference on microleakage of dentin-bordered composite restorations using single or double coats of adhesive from one-bottle adhesive systems. METHODS AND MATERIALS: The enamel surface was removed from freshly extracted bovine teeth, and standardized Class V cavities (3 x 3 x 1.5 mm) were made at the cervical areas of buccal surfaces. Teeth were restored and grouped according to type of adhesive systems [Prime Bond 2.1 (PB2.1), Prime & Bond NT (PBNT), and Single Bond (SB)] and to the number of coats (one or two) to be used. The restorations were polished and immersed in a 0.5% aqueous solution of basic fuchsin for four hours. Teeth were then sectioned and the most infiltrated section of each tooth was selected under magnification, scanned, and quantitatively analyzed using a computer program. Data were analyzed using two-way analysis of variance (ANOVA) and Student-Newman-Keuls (a=0.05). RESULTS: Groups without filler content (PB2.1 and SB) showed no difference in microleakage using single or double coats. However, PBNT (with nanofiller) showed statistically less microleakage when only one coat was applied. The influence of the number of coats of the adhesive systems on dentin margin microleakage was material dependent. CONCLUSION: All adhesive systems demonstrated microleakage, however, it could be minimized using two coats of non-filled or one coat of a filled adhesive system.

Influence of temperature on the spreading velocity of simplified-step adhesive systems.

BACKGROUND: Flowability and viscosity vary for different adhesive systems owing to differences in their composition. These characteristics can be modified by environmental temperature. PURPOSE: The purpose of this study was to determine the influence of temperature on the spreading (flow capacity) of simplified-step adhesive systems. MATERIALS AND METHODS: Spreading velocities of adhesive systems (Adper Single Bond and Single Bond Plus [3M ESPE, St. Paul, MN, USA]; Prime & Bond 2.1 and Prime & Bond NT [Dentsply Indústria e Comércio Ltda, Petrópolis, RJ, Brazil]; Adper Prompt [3M ESPE]; and One Up Bond F [Tokuyama Corp, Tokyo, Japan]) were analyzed at intervals of 10, 15, 20, and 30 seconds at both 25 degrees C and 37 degrees C by placing 10 microL drops on a glass slide surface with an inclination of 45 degrees. The spreading of each adhesive system was measured in millimeters per second. RESULTS: Data were analyzed by two-way analysis of variance and Student-Newman-Keuls tests. Regression analysis was used to determine a correlation between spreading velocity and time. Statistical significance was considered at a confidence level of 95%. Temperature influenced the spreading velocity, increasing it for Single Bond and Prime & Bond 2.1 and decreasing it for Adper Prompt (p < .05). No differences on spreading were observed for the other adhesives studied (p >.05). Regression analysis of each adhesive system demonstrated an inverse correlation between mean spreading velocity and time (R2 = .999) on both temperatures. CONCLUSIONS: Temperature increases yielded an increase of spreading for Single Bond and Prime & Bond 2.1. The influence of temperature on the spreading velocity was material dependent. CLINICAL SIGNIFICANCE: Environmental temperature can influence the rate of spreading of the adhesive system in clinically relevant times and may influence adhesive thickness on cavity walls.

Influência do posicionamento do espécime na resistência adesiva à dentina e na espessura da camada de sistemas adesivos / Influence of dentin surface on bond strength and adhesive layer thickness

Investigou-se a influência da inclinação das paredes de dentina (paralela ou perpendicular à ação da gravidade) e da variação regional dos espécimes (terços cervical ou oclusal) na resistência adesiva e na espessura da camada de adesivo. Vinte e cinco molares humanos foram seccionados no sentido mésio-distal e paralelamente ao seu longo eixo, obtendo-se secções vestibulares e linguais, as quais foram lixadas produzindo-se superfícies planas de dentina. Sistemas adesivos (Adper Single Bond-SB e Prime & Bond 2.1- PB2.1) foram aplicados na dentina, ora paralelamente ora perpendicularmente à ação da gravidade, padronizando-se o volume de adesivo (3,5 µl por gota) através do uso de uma micropipeta e seguindo-se as instruções dos fabricantes. Os grupos de estudo foram: 1A (SB, paralelo), 1B (SB, perpendicular), 2A (PB2.1, paralelo) e 2B (PB2.1, perpendicular). Após 24h de armazenamento em água deionizada a 37°C, espécimes foram preparados na forma de palitos de dentina com área adesiva de 0,8 mm2, aproximadamente. Na seqüência, foi determinada a espessura do adesivo de cada espécime, em micrômetros (µm), sob microscopia óptica (200X de aumento) e auxílio do programa Image Pro-Plus 4.5. Posteriormente, os espécimes foram submetidos à microtração sob velocidade de 0,5 mm/min. Todos os espécimes fraturados foram examinados sob microscopia óptica (40X de aumento) para a determinação dos planos de fratura. Os dados coletados foram submetidos aos testes ANOVA a 1 e 2 critérios e SNK (α= 0,05). Para determinação da correlação entre resistência adesiva e espessura do adesivo foi utilizado o teste de Correlação de Pearson. Os valores médios (MPa±d.p.) de resistência adesiva dos grupos 2A (52,93±15,19) e 2B (52,27±16,54) foram superiores àqueles dos grupos 1A (39,09±12,90) e 1B (32,94±12,42), independente da inclinação das paredes de dentina dos mesmos. Não houve diferença nos valores de resistência adesiva à dentina, independente da variação regional do espécime. Os valores médios (µm±d.p.) de espessura da camada de adesivo dos grupos 1A (11,24±2,92) e 1B (18,11±7,31) foram superiores àqueles dos grupos 2A (4,20±1,81) e 2B (3,87±1,29) (p > 0,05). O grupo 1B promoveu os maiores valores de espessura de adesivo, seguido do grupo 1A. As espessuras do adesivo nos grupos 2A e 2B apresentaram-se similares entre si. Houve influência da variação regional do espécime na espessura de adesivo somente para o grupo 1B. Não houve correlação entre resistência adesiva e espessura de adesivos para ambos SB e PB2.1 (r = -0,224, p = 0,112 e r = 0,099, p = 0,491, respectivamente). Conclui-se que a influência da inclinação das paredes de dentina e da variação regional dos espécimes na espessura da camada de adesivo é material-dependente, porém não influem na resistência adesiva dos sistemas adesivos à dentina.

To determine the effect of the inclination of dentin surfaces (parallel or perpendicular to the force of gravity) and the regional variation of specimens (cervical or occlusal thirds) on the dentin bond strength and adhesive layer thickness. Twenty-five extracted human molars were sectioned in a mesio-distal direction to expose flat dentin. Standardized drop volumes of adhesive systems (Single Bond-SB and Prime & Bond 2.1-PB2.1) were applied to dentin according to manufacturers instructions. Teeth were randomly divided into the following groups: 1A (SB, parallel), 1B (SB, perpendicular), 2A (PB2.1, parallel) and 2B (PB2.1, perpendicular). Teeth were stored in 37°C distilled water for 24h and then serially sectioned to obtain sticks with cross-sectional area of approximately 0.8 mm2 for microtensile bond strength test (MTBS). The thickness of adhesive layer of the MTBS specimen was determined in a light microscope at 200X magnification. Forty-eight hours after adhesion procedures the specimens were subjected to MTBS at a crosshead speed of 0.5 mm/min. After testing, the fracture modes of each specimen were determined by examination under a 40X magnification. One and two-way ANOVA and Student- Newman-Keuls-SNK tests were performed do determine differences in MTBS and in adhesive layer thickness among groups. The correlation between MTBS and adhesive layer thickness was compared with Pearson Product Moment Correlation (α= 0.05). Mean values (MPa±s.d.) for bond strength were higher for groups 2A (52.93±15.19) and 2B (52.27±16.54) than for groups 1A (39.09±12.90) and 1B (32.94±12.42), regardless of the position of dentin surfaces. There was no difference in MTBS, despite the regional variation of specimens. The thickness of adhesive systems (µm±s.d.) was higher for groups 1A (11.24±2.92) and 1B (18.11±7.31) than those for groups 2A (4.20±1.81) and 2B (3.87±1.29). Group 1B provided the greater mean values of adhesive thickness followed by the Group 1A. Similar adhesive thicknesses were found for Groups 2A and 2B, but significantly lower than the other groups. There was a significant influence of the regional variation of specimens on the adhesive thickness of group 1B. No correlation was found between bond strength and adhesive layer thickness for both SB and PB 2.1 (r = -0.224, p = 0.112 and r = 0.099, p = 0.491, respectively). The inclination of dentin surface and the regional variation of specimens on the adhesive layer thickness are materialdependent. These variables do not influence the adhesive systems bond strength to dentin.

Influência do instrumental nas características superficiais pós-acabamento e polimento de restaurações de resinas compostas / Instrumental influence on the superficial characteristics after finishing and polishing composite resin restorations

Acabamento e polimento de restaurações de resinas compostas, embora muitas vezes negligenciados, são responsáveis pela caracterização superficial e restituição anatômico-funcional do conjunto dente-restauração. No entanto, devido aos diversos materiais e instrumentos que podem ser empregados, as etapas de acabamento e polimento podem levar a diferentes características superficiais nas restaurações de resina composta e no dente, as quais são comparadas e exemplificadas, neste artigo, sob forma de fotomicrografias em microscópio eletrônico de varredura.

Efeitos das diversas técnicas de acabamento e polimento sobre as características superficiais das restaurações de resina composta / Effects of several finishing and polishing on superficial characteristics of resin composite restorations

As etapas de acabamento e polimento de rstaurações de resinas compostas são responsáveis pela caracterização supeficial e restituição anatômico-funcional do conjunto dente-restauração, e, quando bem realizadas, permitem uma saudável relação com o periodonto. No entanto, o resultado final desses procedimentos é dependente do material e das várias técnicas que podem ser utilizadas

Estudo de microinfiltração: análise crítica da matodologia / Microleakage studies: critical analysis of methodology

A infiltração marginal permanece como fator limitante na longevidade das restaurações, principalmente as de resina composta. O entedimento dos fatores que causam a desadaptação marginal é preponderante para o desenvolvimento de técnicas e materiais que a minimizem. Da mesma maneira, a escolha de uma técnica padronizada para análise da microinfiltração é importante para a discussão dos resultados das diversas pesquisas nessa área. Uma vez que não há padronização das técnicas de análise da infiltração marginal por meio de corantes nos diversos estudos publicados na literatura, realizamos uma discussão crítica de fatores inerentes a algumas técnicas, assim como procedimentos operatórios, que podem interderir nos resultados. Verificamos que várias são as metodologias empregadas e que, talvez, a facilidade de realização das mesmas seja o principal fator de sua escolha

Effect of the number of thermocycles on microleakage of resin composite restorations

A ciclagem térmica tem por objetivo simular, in vitro, as mudanças térmicas intra-orais que ocorrem clinicamente. Sendo o seu efeito bastante discutido, o presente trabalho tem como objetivo avaliar a relação da ciclagem térmica e o número de ciclos na infiltração marginal. Foram confeccionadas cavidades classe V com dimensões de 3 mm de altura, 3 mm de largura e 1,5 mm de profundidade, em dentes bovinos. Os dentes foram restaurados com o sistema Single Bond/Z250 (3M/ESPE) e, então, divididos em 5 grupos de 10 dentes cada: grupo 1 (controle) sem ciclagem; grupos 2, 3, 4 e 5 com 500, 1.000, 2.500 e 5.000 ciclos, respectivamente (5º-55º ± 2ºC, 15 segundos por banho). A seguir, os dentes foram seccionados e analisados em microscópio com 100 X de aumento para a escolha da fatia mais infiltrada, que foi escaneada e quantificada pelo programa ImageTool. Os dados submetidos ao teste ANOVA a um critério não apresentaram diferença significante (p > 0,05), resultando em valores médios de infiltração em milímetros: grupo 1 (3,92), grupo 2 (3,13), grupo 3 (4,48), grupo 4 (4,33) e grupo 5 (3,42). A análise dos dados permitiu concluir que não há relação entre o aumento do número de ciclos e o aumento da infiltração marginal.

Effect of the number of thermocycles on microleakage of resin composite restorations.

Thermocycling simulates, in vitro, thermal changes that occur in the oral cavity. The aim of this study was to evaluate the influence of the number of cycles on microleakage. Class V cavities (1.5 mm deep, 3 mm in height and 3 mm in width) were prepared in bovine teeth, restored with a Single Bond/Z250 restorative system (3M/ESPE) and then divided into five groups of ten teeth each: group 1 was not thermocycled (control group), and groups 2, 3, 4 and 5 were thermocycled 500, 1,000, 2,500 and 5,000 times, respectively (5 degrees -55 degrees +/- 2 degrees C, 15 s dwell time). The teeth were immersed in 0.5% basic fuchsin aqueous solution for 24 h, sectioned and the sections with the highest degree of microleakage were selected, scanned and the extent of dye penetration was measured by the ImageTool program. The results submitted to one-way ANOVA showed no significant differences between the groups (p > 0.05). The averages of microleakage values in millimeters were: group 1 (3.92); group 2 (3.13); group 3 (4.48); group 4 (4.33) and group 5 (3.42). Thus, it was concluded that there is no relation between the increase of the number of cycles and the increase in microleakage.

Estética em dente anterior: uma integraçäo multidisciplinar / Esthetics in anterior teeth: a multidisciplinar integration

O objetivo deste trabalho é apresentar uma soluçäo clínica para casos de dentes anteriores perdidos, através da integraçäo multidisciplinar. Apresentamos o caso clínico de uma criança de sete anos com perda do elemento 11 por traumatismo. Após um reimplante fracassado, a opçäo de tratamento escolhida foi a associaçäo das técnicas de transplante dental autógeno e de dentística restauradora, devido aos custos x benefícios frente às razöes biológicas, funcionais e sócio-econômicas