Selamento dentinário imediato em restauração semidireta: relato de caso / Immediate dentin sealing in semi-direct restoration: case report

O selamento dentinário imediato é um procedimento essencial na Odontologia, que envolve a aplicação de agentes de selamento na interface entre a dentina e o material restaurador imediatamente após a remoção da cárie e do preparo da cavidade dentária. Este processo busca selar os túbulos dentinários expostos, proporcionando proteção à polpa dentária. O presente caso foi realizado em um paciente do sexo masculino, 56 anos que se queixou de desconforto no elemento dentário 17. Após avaliação clínica e radiográfica, foi constatado uma ampla restauração desadaptada na porção mesio - oclusal do referido dente, sendo que o elemento em questão não possui tratamento endodôntico. Após planejamento e assinatura do TCLE, os seguintes passos foram realizados: remoção da lesão cariosa do dente 17, seguido da realização do levantamento marginal mesial e a realização do selamento dentinário imediato. Moldagem com silicone de adição do dente em questão e do antagonista, assim como registro da mordida. Foi confeccionada uma restauração semidireta em resina composta sob o modelo de gesso obtido. A cimentação da restauração foi feita na consulta seguinte, cumprindo os requisitos fundamentais para restaurar forma, função e estética, resultando na melhoria da qualidade de vida do paciente(AU)

Immediate dentin sealing is an essential procedure in dentistry, involving the application of sealing agents at the interface between dentin and the restorative material immediately after caries removal and cavity preparation. This process aims to seal exposed dentinal tubules, providing protection to the dental pulp. The present case involved a 56-year-old male patient who complained of discomfort in tooth number 17. After clinical and radiographic evaluation, a wide, maladapted restoration in the mesio-occlusal portion of the tooth was identified, with no endodontic treatment in the affected element. Following planning and informed consent, the following steps were taken: removal of the carious lesion from tooth number 17, followed by the execution of mesial marginal elevation and immediate dentin sealing. Silicone addition molding of the affected tooth and antagonist, along with bite registration, was performed. A semi-direct restoration in composite resin was fabricated based on the obtained gypsum model. The restoration was cemented in the subsequent appointment, meeting the essential requirements to restore form, function, and aesthetics, resulting in an improvement in the patient's quality of life(AU)

Restauração indireta em resina composta: um relato de prontuário / Indirect resin composite restoration: a dental record report

Restaurações diretas em resina composta são amplamente utilizadas em odontologia para restaurar dentes posteriores. Todavia, quando há grande destruição coronária, onde a distância do istmo excede dois terços da distância intercuspídea, as restaurações indiretas em resina composta são indicadas. O presente estudo teve como objetivo relatar a análise de um prontuário de um paciente que recebeu uma restauração indireta em resina composta em dente posterior amplamente destruído. Através da análise de prontuários de pacientes atendidos nas disciplinas de Estágios Supervisionados do Curso de Odontologia da FSG Centro Universitário no ano de 2023, foi selecionado um prontuário de um paciente que compareceu a clínica odontológica da FSG com uma restauração em amálgama fraturada com reparo em resina composta que apresentou sintomatologia dolorosa. O procedimento diagnóstico ocorreu através de exame clínico e radiográfico, que constatou a indicação de substituição da restauração insatisfatória e realização de uma restauração indireta em resina composta. Os resultados estéticos e funcionais apresentados demostraram a viabilidade da técnica restauradora indireta em resina composta para reabilitar dentes posteriores com ampla destruição coronária(AU)

Direct composite resin restoration are widely used in dentistry to restore posterior teeth. However, when there is large coronary destruction, that the distance from the isthmus exceeds two- thirds of the intercuspal distance, indirect composite resin restorations are indicated. This study aimed to report the analysis of a dental record of a patient who received an indirect restoration in composite resin in a badly destroyed posterior tooth. Through the analysis of dental records of patients seen in the disciplines of Supervised Internship of the Dentistry Course at FSG Centro Universitário in the year 2023, the dental record of a patient who attended the FSG dental clinic with fractured amalgam restoration with composite resin repair was selected who had painful symptoms. The diagnostic procedure took place through clinical and radiographic examination, which revealed the indication of replacing the unsatisfactory restoration and carrying out an indirect restoration in composite resin.The aesthetic and functional results presented demonstrated the viability of the indirect composite resin restoration technique for rehabilitating posterior teeth with extensive coronal destruction(AU)

Restauração em resina composta semidireta em dente posterior: relato de caso / Semi-direct composite restoration in posterior toth: a case report

A escolha da técnica restauradora desempenha papel fundamental na eficácia e duração de um tratamento reabilitador. O objetivo deste relato de caso foi descrever a utilização da técnica semidireta para a confecção de uma restauração em resina composta em um primeiro molar inferior. A paciente apresentava uma restauração insatisfatória no dente 36, que necessitava ser substituída devido à infiltração por cárie. Optou-se pela técnica semidireta devido à amplitude da cavidade, que envolvia estruturas de suporte, e pela combinação das vantagens das abordagens direta e indireta. O procedimento envolveu a remoção de tecido cariado, a aplicação de hidróxido de cálcio pasta, seguida da aplicação de uma fina camada de ionômero de vidro e, posteriormente, resina fluída para realizar o selamento dentinário. O preparo foi realizado seguindo os princípios necessários. O elemento em questão foi moldado com silicone de adição e o arco antagonista, com alginato. Ambos modelos foram vertidos com silicone para modelos semirrígidos e montados em oclusor de peças de brinquedo. A restauração semidireta foi confeccionada em resina composta Filtek Z350 XT, respeitando a anatomia do dente 36. Pigmentos foram utilizados para aprimorar detalhes estéticos. Após acabamento e polimento, a peça foi condicionada e cimentada com cimento dual Relyx Ultimate. Pode-se concluir que a abordagem restauradora por meio da técnica semidireta construída em modelo semirrígido é uma opção terapêutica conservadora e vantajosa para dentes com extensa destruição coronária. Essa técnica possibilita a restauração de forma eficaz, garantindo tanto a estética quanto a função adequada do dente afetado(AU)

The choice of restorative technique plays a fundamental role in the effectiveness and duration of rehabilitation treatment. The objective of this case report was to describe the use of the semi-direct technique to create a composite resin restoration in a lower first molar. The patient had an unsatisfactory restoration on tooth 36, which needed to be replaced due to cavity infiltration. The semi-direct technique was chosen due to the amplitude of the cavity, which involved support structures, and the combination of advantages of the direct and indirect approaches. The procedure involved the removal of carious tissue, and the application of calcium hydroxide paste, followed by the application of a thin layer of glass ionomer and, subsequently, fluid resin to seal the dentin. The preparation was carried out following the necessary principles. The element in question was molded with addition silicone and the antagonist arch was molded with alginate. Both models were poured with silicone for semi-rigid models and mounted on toy parts occluders. The semi-direct restoration was made in Filtek Z350 XT composite resin, respecting the anatomy of tooth 36. Pigments were used to improve aesthetic details. After finishing and polishing, the piece was conditioned and cemented with Relyx Ultimate dual cement. It can be concluded that the restorative approach using the semi-direct technique built on a semi-rigid model is a conservative and advantageous therapeutic option for teeth with extensive coronal destruction. This technique allows for effective restoration, ensuring both the aesthetics and adequate function of the affected tooth(AU)

Modificação de uma resina composta Bulk Fill Flow com extrato acetônico da casca da romã / Modification of a Bulk Fill Flow composite resin with acetonic extract from pomegranate peel

Introdução: A cárie dentária ainda se constitui um problema de saúde pública. Áreas adjacentes a restaurações são frequentemente acometidas por cárie. Por mais que as resinas compostas estejam sendo estudadas e melhoradas, ainda não apresentam atividade antimicrobiana. As cascas da romã (Punica Granatum) são um recurso potencial para compostos bioativos como fenólicos, proantocianidinas e flavonoides, além de apresentarem atividade antioxidante e efeito inibitório contra bactérias Gram-negativas e Gram-positivas. Objetivo: modificar a resina composta Opus Bulk Fill Flow (FGM®) com o extrato acetônico da casca da romã em diferentes concentrações e avaliar a rugosidade da superfície e mudança de cor. Metodologia: foi realizada a extração de 5g de casca da romã utilizando 100mL de solvente acetona 70%. Após rotaevaporação, filtragem e liofilização do extrato, este foi macerado, peneirado e pesado em concentrações diferentes a partir da concentração inibitória mínima capaz de inibir o crescimento de Streptococcus mutans ATCC 700610. A resina composta Opus Bulk Fill Flow foi modificada com esse extrato em diferentes concentrações de forma a gerar 5 grupos: Controle 0 µg (n=10), G930 µg (n=10), G1860 µg (n=10), G3730 µg (n=10) e G7460 µg (n=10). Rugosidade (Ra), diferença de cor (ΔE00) e índice de brancura (WID) foram submetidos aos testes de normalidade. Os dados não-paramétricos de Ra foram submetidos ao teste de Kruskal-Wallis com pós-teste de Dunn e os dados paramétricos do ΔE00 e WID foram submetidos ao teste ANOVA 1 Fator com pósteste de Tukey por meio do software GraphPad Prism 8 e Microsoft Excel 2019. Resultados: Verificou-se que a média do índice de brancura (WID) diminuiu conforme o aumento da concentração do extrato na resina modificada (p<0,05), assim como, as resinas modificadas se tornaram, visivelmente a olho nu, um pouco mais amareladas. Após 1 mês, as amostras dos grupos experimentais sofreram a mesma variação de cor (ΔE00) que o grupo controle, uma vez que os valores das médias foram semelhantes. Portanto, todos os grupos apresentaram estabilidade de cor. A rugosidade superficial (Ra) não mostrou diferença estatisticamente significativa (p>0,05). Todos os grupos apresentaram médias com valores similares a 0,06µm. Conclusão: A alteração de cor na resina, com a inserção do extrato, ainda na maior concentração, se manteve na classificação do matiz A. O que não afeta as propriedades organolépticas e pode ser considerada uma cor similar à cor dos dentes naturais. A adição do extrato na resina manteve a rugosidade superficial de todos os grupos dentro do valor ideal, prevenindo a adesão de biofilmes e microrganismos e proporcionando conforto ao toque da língua (AU).

Introduction: Dental caries still constitutes a public health problem. Areas adjacent to restorations are often affected by caries. Even though resin composites are being studied and improved, they still do not have antimicrobial activity. Pomegranate peels (Punica Granatum) are a potential resource for bioactive compounds such as phenolics, proanthocyanidins and flavonoids, in addition to presenting antioxidant activity and inhibitory effects against Gram-negative and Gram-positive bacteria. Objective: to modify the Opus Bulk Fill Flow (FGM™) resin composite with the acetone extract of pomegranate peel in different concentrations and evaluate the surface roughness, and color change. Methodology: 5g of pomegranate peel was extracted using 100mL of 70% acetone solvent. After rotary evaporation, filtering and lyophilization of the extract, it was macerated, sieved and weighed at different concentrations based on the minimum inhibitory concentration capable of inhibiting the growth of Streptococcus mutans ATCC 700610. The Opus Bulk Fill Flow resin composite was modified with this extract in different concentrations to generate 5 groups: Control 0 µg (n=10), G930 µg (n=10), G1860 µg (n=10), G3730 µg (n=10) e G7460 µg (n=10). Roughness (Ra) and color difference (ΔE00) were subjected to normality tests and non-parametric data were subjected to the Kruskal-Wallis test with Dunn's post-test using GraphPad Prism 8 and Microsoft Excel 2019 software. Results: It was found that the average whiteness index (WID) decreased as the concentration of the extract in the modified resin increased (p<0.05), as well as the modified resins became, visibly to the naked eye, a little more yellowish. After 1 month, samples from the experimental groups suffered the same color variation (ΔE00) as the control group, since the average values were similar. Therefore, all groups showed color stability. Surface roughness (Ra) did not show a statistically significant difference (p>0.05). All groups presented average values similar to 0.06µm. Conclusion: The color change in the resin, with the insertion of the extract, even at the highest concentration, remained in the classification of hue A. This does not affect the organoleptic properties and can be considered a color similar to the color of natural teeth. The addition of the extract to the resin composite maintained the surface roughness of all groups within the ideal value, preventing the adhesion of biofilms and microorganisms and providing comfort to the touch of the tongue (AU).

Reanatomização estética dos dentes anteriores com resina composta: relato de caso / Reanatomización estética de dientes anteriores com resina compuesta: reporte de caso / Aesthetic reanatomization of front teeths with composite resin: case report

Introdução: A alta busca por tratamentos estéticos levou a indústria odontológica a aprimorar suas técnicas e desenvolver materiais com novas características que possibilitam a mimetização da estrutura dental, associando alta qualidade estética à saúde. Para isso, é necessário uma anamnese detalhada e exame físico intra e extrabucal, análise morfológica dos dentes e da face, para que a reabilitação proposta seja adequada. Objetivo: O objetivo deste estudo é descrever um caso clínico de reanatomização dos elementos dentais anteriores superiores, por meio de restaurações diretas em resina composta, restabelecendo a estética e função da paciente. Relato de caso: Paciente do sexo feminino, 19 anos, procurou a Clínica Escola da Faculdade de Odontologia do Recife -FOR relatando insatisfação com seu sorriso e declarou não estar disposta a se submeter a um tratamento ortodôntico. Ao realizar o exame clínico, observou-se que havia desalinhamento dos elementos dentários ântero-superiores. Após a realização do enceramento diagnóstico e validação da mesma através do mockupcom resina bisacrílica, optou-se por realizar a reanatomização estética com resina composta nanohíbrida, de forma conservadora, ou seja, sem desgastar os dentes em questão. Conclusão: As etapas do planejamento foram fundamentais para maior previsibilidade e obtenção do excelente resultado. Os materiais e técnicas selecionados para realização dos procedimentos aliaram características de resistência e estética, visando maior longevidade (AU).

Introduction: The high demand for aesthetic treatments has led the dental industry to improve its techniques and develop materials with new characteristics that allow mimicking the tooth structure, associating high aesthetic quality with health. This requires a detailed anamnesis,intra-and extraoral physical examination, and morphological analysis of the teeth and faceto allow an adequate proposed rehabilitation. Objective:The objective of this study is to describe a clinical case of reshaping of upper anterior teeth, by direct composite resin restorations, reestablishing the patient's aesthetics and function. Case report:Female patient, 19 years old, sought the Clínica Escola da Faculdade de Odontologia do Recife -FOR, reporting dissatisfaction with her smile and declared that she was unwilling to undergo orthodontic treatment. Clinical examinationrevealed misalignment of the upper anteriorteeth. After diagnostic waxing and validation by mockup with bis-acryl resin, it was decided to perform the aesthetic reshaping with nanohybrid composite resin in a conservative manner, i.e., without tooth wearing . Conclusion:The planning stages were fundamental for greater predictability and obtaining excellent results. The materials and techniques selected for the procedurescombined resistance and aesthetic characteristics, aiming at greater longevity (AU).

Introducción:La gran demanda para tratamientos estéticos ha llevado a la industria dental a mejorarsus técnicas y desarrollar materiales con nuevas características que permitan mimetizar la estructura dental, combinando una alta calidad estética con la salud. Para que esto ocurra, es necesario realizer una anamnesis detallada y un examen físicointra y extraoral, así como un análisis morfológico de los dientes y de la cara, para que la rehabilitación propuesta sea da adecuada. Objetivo:El objetivo de este studio es describir un caso clínico de reanatomización de los elementos dentales de resinacompuesta, restabeleciendo la estética y función de la paciente. Informe de caso:Paciente del sexo feminine, 19 años de edad, que acudió a la Clínica Escuela de La Facultad de Odontología de Recife ­FOR menifestando insatisfaccíon con su sonrisa y declarando no estar dispuesta a someterse a tratamiento de ortodoncia. En el examen clínico se observódesalineación de los elementos dentarios anterosuperiores. Tras realizar un encerado diagnóstico y validarlo con un mock-up de resina bisacrílica, se optó porrealizer una reanatomización estética con resina compuesta nanohíbrida de forma conservadora, es decir, sin desgastarlos dientes implicados. Conclusión:Las etapas de planificacíon han sido fundamentales para una mayor previsibilidad y la obtención de excelentes resultados. Los materiales y técnicas seleccionados para la realización de los procedimentos combinaron características de resistencia y estética, buscando una mayor longevidad (AU).

Bisphenol A released and ultrastructural changes in dental composite resins

Dental composite resins may release bisphenol-A or similar molecules affecting patient health and the environment. This study measured bisphenol-A release from three commonly used in patients composite resins (Filtek™ Z350 XT, Filtek™ P60, Filtek™ Bulk Fill) immersed in three liquid mediums (artificial saliva, 0.001 M lactic acid and 15% ethanol) and assessed the changes in the surface micromorphology.The released BPA was measured by HPLC at basal time (t=0), 1 h, 1 d, 7 d and 30 d. Topographic analysis of specimens was performed by scanning electron microscopy (SEM). The data were analyzed using one-way ANOVA and Tukey post-hoc test (P < 0.05). BPA in solution increased significantly in the three DCRs immersed in 0.001 M lactic acid at all times. SEM micrographs of the specimen in 0.001 M lactic acid disclosed more structural defects than others. The surface of the three composite resins was morphologically affected by their immersion in all solutions. SEM evidenced that the dental materials underwent erosion and cracks with filler particles protruding from the surface. The morphological changes in tested dental materials produced by exposure to these solutions are potentially dangerous to patients by causing caries, infections, and partial loss of dental material.

Alternative method of photopolymerization of composite resin specimen for flexural strength test / Método alternativo de fotopolimerização de resinas compostas para teste de flexão

The flexural resistence is one of the most used test in researchs of mechanical characterization of resin composites for dental restoration. ISO 4049 photopolymerization technique performed static application stages of light tip. To polymerize the entire area of the specimen some areas must receive extra radiation. These areas with extra radiation are called overlap areas. In an attempt to remedy this problem, this research compared the ISO method with a new method using constant movement (CM) during photopolymerization. Twenty specimens (SPs) were produced with 25 x 2 x 2 mm, for each group, 10 specimens being polymerized by the static technique recommended by the ISO-4049 and 10 specimens polymerized by the CM technique for each LED curing light used. After Tukey's statistical analysis, it was found that there was no statistical difference in relation to flexural strength (FS) and for the flexural modulus of elasticity (EF). However, the standard deviation of both FS and EF were much lower in MC than in ISO. Therefore, the photopolymerization by CM of the samples for the flexural strength test proved to be a possible solution to the problem of overlap of the technique proposed by ISO.

O teste de flexão é um dos mais utilizados em pesquisa de caracterização mecânica de compósitos resinosos para restauração dentária. A técnica ISO 4049 é feita em etapas com aplicação estática da luz. Para que toda a área do corpo de prova receba esta radiação é preciso que outras áreas recebam radiação extra. Na tentativa de sanar tal problema, esta pesquisa comparou o método da ISO com um método que utiliza um movimento constante (MC) durante a fotopolimerização. Foram produzidos 20 corpos de provas (CPs) com 25 x 2 x 2 mm, para cada grupo, sendo 10 polimerizados pela técnica estática recomendada pela normativa ISO-4049 e 10 polimerizados pela técnica de movimentação contínua (MC) para cada fotopolimerizador LED utilizado. Após análise estatística de Tukey apurou-se que não houve diferença estatística em relação à resistência à flexão (RF) e para o módulo de elasticidade em flexão. Porém, percebe-se, que o desvio padrão tanto da RF quanto do EF foram bem menores em MC do que em ISO. Sendo assim, a fotopolimerização em movimentação constante (MC) das amostras para o teste de resistência à flexão se mostrou como uma possível solução para o problema de sobreposição na técnica proposta pela ISO.

Clinical observation of the success rate of flowable resin filling wedge-shaped defects / 实用口腔医学杂志

90 patients(251 teeth)with wedge-shaped defects were included and randomly divided into the study group(45 patients with 125 teeth,treated with flowable resin filling)and the control group(45 patients with 126 teeth,treated with composite resin).The success rates were compared between the 2 groups.The results showed that the success rate of flowable resin was basically the same with that of com-posite resin,and the clinical operation time was shorter.

Design,synthesis and properties of oral composite resin monomers with different photoinitiators / 中国组织工程研究

BACKGROUND:At present,the dental composite resin filling material composed of resin matrix monomer is the first choice material for the filling treatment of dental defects,but with the increase of its use time in the oral environment,the dental tissue will develop secondary caries and the filling material will wear and break.The main cause of these problems is the polymerization shrinkage of the filling material and its mismatch with the mechanical properties of the dental tissue. OBJECTIVE:To synthesize a new type of dental composite resin monomer by adding initiators with different components,to improve the traditional double bond conversion rate of the system and further improve the mechanical properties of the material. METHODS:A new composite resin matrix system was prepared by adding different initiators to the monomer of 3,3′,5,5′-tetramethoxybiphenyl-4,4′-diol epoxy acrylate resin.In group A,camphorquinone with a mass fraction of 1.1%was added.In group B,1-phenyl-1,2-propanedione with a mass fraction of 2.1%was added.In group C,a mixture of camphorquinone and 1-phenyl-1,2-propanedione(a mass ratio of the two was 1:1)with a mass fraction of 3.1%was added.The double bond conversion,polymerization shrinkage and mechanical properties of the samples were determined. RESULTS AND CONCLUSION:(1)The double bond conversion rate of groups B and C was higher than that of group A(P<0.05).The polymerization shrinkage of group B was higher than that of group A(P<0.05),while that of group C was lower than that of group A(P<0.05).(2)The flexural strength,elastic modulus and compressive strength of groups B and C were higher than those of group A(P<0.05,P<0.01).Vickers hardness of group B was higher than that of group A(P<0.05),and the Vickers hardness of group C was lower than that of group A(P<0.01).(3)These findings suggest that 1-phenyl-1,2-propanedione is an initiator with ideal performance.The combined application of 1-phenyl-1,2-propanedione and camphorquinone can effectively improve the double bond conversion rate of the resin matrix system and further improve the mechanical property of the resin.

Effect of Morinda citrifolia juice on the bonding strength and nanoleakage of crowns dentin / 口腔疾病防治

Objective@#To explore the effect of Morinda citrifolia juice (MCJ) combined with ethylene diamine tetraacetic acid (EDTA) on premolar bonding strength and nanoleakage and compare the results with those of the most commonly used root canal irrigation solution, sodium hypochlorite (NaClO), to provide a reference for clinical application.@*Methods@#This study was approved by the ethics review committee. Sixty-three human premolars extracted for orthodontic treatment were randomly divided into a control group (distilled water group) and 6 experimental groups according to the different rinsing solutions used after the surface enamel was removed. The experimental groups included Group A (2.5% NaClO), Group B (5.25% NaClO), Group C (6% MCJ), Group D (2.5% NaClO-17% EDTA), Group E (5.25% NaClO-17% EDTA), and Group F (6% MCJ-17% EDTA) (n = 9). After soaking in the corresponding rinsing solution for 20 minutes, they were layered and stacked on their surfaces to form 4 mm × 4 mm × 3 mm Z350 resin blocks. Six samples from each group were cut into 1 mm × 1 mm × 8 mm specimen strips for microtensile bonding strength testing. The fracture type was determined under a stereomicroscope, and the remaining 3 samples from each group were aged and cut into 1 mm thick slices for interface nanoleakage testing and scanning electron microscopy observation of the resin dentin bonding interface.@*Results@#There were significant differences in the microtensile bonding strength among the groups (P<0.05), and the control group had the highest bonding strength. Among experimental groups, Group B had the lowest bonding strength, mainly bonding interface fracture, and Group F had the highest bonding strength, mainly mixed fracture. There were significant differences in nanoleakage among all groups (P<0.05), and the control group had the lowest nanoleakage value. Among experimental groups, Group B had the highest nanoleakage, with resin protrusions being unaltered, and Group F had the lowest nanoleakage value, with resin protrusions being thick and dense.@*Conclusion@#The higher the concentration of NaClO was, the worse the bonding strength and edge sealing of the crown dentin were. The effects of root canal irrigation with MCJ and EDTA on the adhesive strength and edge sealing of crown dentin were less pronounced than those of root canal irrigation with NaClO and EDTA.

Color variation of composite resins in relation to the Vita Classical shade guide: colorimetric analysis

Aim: The aim of this study was to verify the color variation between different composite resins and the Vita Classical Shade Guide. Methods: Two-millimeter thickness samples were made (n = 6) from eight commercial brands of composite resin (shade A2): Charisma (Kulzer), Forma (Ultradent), Harmonize (Kerr), Luna (SDI), Opallis (FGM), Oppus Bulk Fill (FGM), Vittra (FGM) and Filtek Z250 XT (3M ESPE). Specimens were stored in distilled water for 7 days and then polished. Color measurements of samples and A2 shade of the Vita Classical Shade Guide were performed using the Vita Easy Shade Advance 4.0 spectrophotometer on a black background. Color variations were calculated using the CIEDE2000 formula, considering values ≥0.81 being noticeable by the human eye and ≥1.77 being clinically unacceptable. Results were statistically analyzed with a 5% significance level. Results: Color variation (ΔE) of composite (E1 ) compared to the Vita Classical Shade Guide (E0 ) was greater than clinically acceptable for all the materials evaluated in this study. Forma (ΔE=2.08 ± sd=0.47) and Filtek Z250 XT (2.50 ± 0.20) had the smallest amount of color variation values found in the results. Harmonize (3.32 ± 0.63) presented values similar to Filtek Z250 XT, but it was worse than Forma. Vittra (3.51 ± 0.28), Charisma (3.80 ± 0.20), Opallis (4.24 ± 0.30) and Luna (5.67 ± 0.20) did not differ among each other and presented higher color variation than Forma, Filtek Z350XT and Harmonize. Oppus Bulk Fill (13.94 ± 1.12) was the composite with the greatest color variation. Conclusions: The findings in this study show that attention should be taken when using the Vita Color Shade Guide for composite shade selection

Evaluation of orthodontists' attitudes and practices regarding residual resin removal methods

ABSTRACT Introduction: The removal of residual resins is a routine procedure in orthodontic clinics and of great importance to the final result of the treatment. Objective: To evaluate the main methods of residual resin removal used by orthodontists, and the main reasons for choosing these methods. Methods: A questionnaire consisting of 21 questions: 6 relating to demographic data and the other 15 relating to two methods used to remove residual resins (drills or pliers) was sent by e-mail to orthodontists registered with the Regional Councils of Dentistry of São Paulo and Rio de Janeiro (Brazil) within April and June, 2023. Questionnaires were sent back by 153 professionals. Results: Residual resin removal is always carried out with high speed drill for 44.7% of the sample, and with low speed drill for 28.7%; 61.3% use irrigation. The multi-laminate carbide bur is used by 82.5% of orthodontists. Pliers are always used by 12.4%. Resin-removing pliers with Widia are used in 39% of cases. The use of high speed was justified by the shorter working time, and the choice of pliers was justified by the smaller damage to the tooth enamel. Conclusion: The most used residual resin removal method was the multi-laminate carbide bur at high speed with irrigation, justified the by shorter working time.

RESUMO Introdução: A remoção de resinas residuais é um procedimento rotineiro na clínica ortodôntica e de grande importância para o resultado final do tratamento. Objetivo: Avaliar os principais métodos para remoção de resinas residuais utilizados por ortodontistas e os principais motivos para a escolha desses métodos. Métodos: Um questionário composto por 21 perguntas: 6 relativas aos dados demográficos e 15 relativas aos métodos de remoção de resinas residuais (brocas ou alicates) foi enviado por e-mail para ortodontistas dos conselhos regionais de São Paulo e Rio de Janeiro entre os meses de abril e junho de 2023, com o total de 153 respostas. Resultados: A remoção de resinas residuais é realizada sempre com brocas em alta rotação para 44,7% da amostra e em baixa rotação para 28,7%; 61,3% utilizam irrigação. A broca carbide multilaminada é utilizada por 82,5% dos ortodontistas. Os alicates são sempre utilizados por 12,4%. O alicate removedor de resina com Wídea é utilizado em 39% dos casos. O uso da alta rotação foi justificado pelo menor tempo de trabalho e a escolha por alicates, justificada pelos menores danos ao esmalte. Conclusão: O método de remoção de resinas residual mais utilizado foi a broca carbide multilaminada em alta rotação com irrigação, justificado pelo menor tempo de trabalho.

Evaluation of polymerization shrinkage stress and cuspal strain in natural and typodont teeth

Abstract To evaluate the polymerization shrinkage stress and cuspal strain (CS) generated in an artificial (typodont) and in a natural tooth using different resin composites. Twenty artificial and 20 extracted natural molars were selected. Each tooth was prepared with a 4x4 mm MOD cavity. The natural and typodont teeth were divided into four experimental groups (n=10), according to the resin composite used: Filtek Z100 (3M Oral Care) and Beautifil II LS (Shofu Dental). The cavities were filled using two horizontal increments and the CS (µS) was measured by the strain gauge method. Samples were sectioned into stick-shaped specimens and the bond strength (BS) (MPa) was evaluated using a microtensile BS test. Shrinkage stress and CS were analyzed using 3D finite element analysis. No difference was found between the type of teeth for the CS as shown by the pooled averages: Natural tooth: 541.2 A; Typodont model: 591.4 A. Filtek Z100 CS values were higher than those obtained for Beautifil II LS, regardless of the type of teeth. No statistical difference was found for the BS data. Adhesive failures were more prevalent (79.9%). High shrinkage stress values were observed for Filtek Z100 resin, regardless of tooth type. The CS of typodont teeth showed a shrinkage stress effect, generated during restoration, equivalent to that of natural teeth.

Envelhecimento bucal precoce e suas consequências para a cavidade oral com foco em reabilitação com resina composta: relato de caso / Early oral aging and its consequences for the oral cavity focusing on rehabilitation with composite resin: case report

O envelhecimento bucal precoce apresenta cada vez uma maior incidência nos consultórios odontológicos e sua degradação aos tecidos orais exige uma atenção por parte do cirurgiãodentista devido ao seu alto grau de complexidade. Esse envelhecimento precoce é causado principalmente por hábitos parafuncionais, dieta ou ambos. Suas consequências são desgastes patológicos dos tecidos dentários, extrusão passiva, perda de dimensão vertical e comprometimento estético e funcional. Por conta disso, o presente estudo teve como objetivo realizar um relato de caso clínico em um paciente jovem e com queixa estética como consequência de hábitos parafuncionais, aonde foram realizados uma reabilitação oral envolvendo aumento da dimensão vertical de oclusão através de Table Tops sem desgastes dentários e restaurações estéticas, ambas com resina composta. Essa reabilitação devolveu a DVO da paciente, trazendo conforto, contatos estáveis, guias de desoclusão e satisfação estética e funcional por parte da paciente(AU)

Early oral aging has an increasing incidence in dental offices and its degradation to oral tissues requires attention from the dentist due to its high degree of complexity. This premature aging is mainly caused by parafunctional habits, diet, or both. Its consequences are pathological wear of dental tissues, passive extrusion, loss of vertical dimension and aesthetic and functional impairment. Because of this, the present study aims to carry out a clinical case report in a young patient with an aesthetic complaint as a result of parafunctional habits, where an oral rehabilitation was carried out involving an increase in the vertical dimension of occlusion through Table Tops without dental wear and aesthetic restorations, both with composite resin. This rehabilitation returned the patient's OVD, bringing comfort, stable contacts, disocclusion guides and aesthetic and functional satisfaction on the part of the patient(AU)

Degree of Conversion and Mechanical Properties of a Commercial Composite with an Advanced Polymerization System / Avaliação do grau de conversão e das propriedades mecânicas de um compósito comercial com sistema avançado de polimerização

ABSTRACT Advanced Polymerization System (APS) technology in a commercial composite resin enables reduction of the concentration of camphorquinone without altering composite physicochemical properties. Aim: The aim of this study was to evaluate the degree of conversion and mechanical properties of a commercial composite with an advanced polymerization system (APS) and compare it to other composites that do not use this system. Materials and Method: Five groups were analyzed. Group 1 (VT: Vittra APS - FGM); G2 (AU: Aura - SDI); G3 (ES: Quick Sigma Stelite - TOKOYAMA); G4 (FZ: Filtek Z350 XT - 3M ESPE); G5 (OP: Opallis -FGM). Degree of conversion (DC, n=3) was analyzed immediately and after 24h by analysis with FTIR spectroscopy. For Knoop hardness (KHN, n=3), 5 indentations were made at the top and bottom of specimens 2 mm thick. Flexural strength (FS, n=10) was determined by the three-point method in a universal testing machine. Polymerization stress (PS) was determined by light-curing the material (1.0 mm high) between polymethylmethacrylate rods in a universal testing machine. Light curing was performed with a Valo Cordless LED (1,000 mW/cm2 x 20 s: 20J). The results were analyzed using ANOVA and complemented by Tukey's test (α=0.05). Results: The highest DC values (immediate and 24h after) were observed for VT and OP resins, followed by FZ, AU and ES. FZ (top and bottom) had the highest KHN values, similar to VT top. AU, ES, OP and VT had statistically different KHN between their top and bottom surfaces. The highest RF values were observed for FZ, followed by OP/VT, ES and AU. The highest TP values were observed for FZ, OP and VT. Conclusion: The Vittra APS resin with a new polymerization system presents satisfactory performance for the parameters evaluated.

RESUMO A tecnologia Advanced Polymerization System (APS) presente em uma resina composta comercial permite reduzir a concentração de canforoquinona sem alterar as propriedades físico-químicas do compósito. Objetivo: o objetivo deste estudo foi avaliar o grau de conversão e as propriedades mecânicas de um compósito comercial com sistema avançado de polimerização (SAP) e comparálo com outros compósitos que não utilizam esse sistema. Materiais e Método: cinco grupos foram analisados. Grupo 1 (VT: Vittra APS - FGM); G2 (AU: Aura - SDI); G3 (ES: Quick Sigma Stelite - TOKOYAMA); G4 (FZ: Filtek Z350 XT - 3M ESPE); G5 (OP: Opallis -FGM). O grau de conversão (GC, n=3) foi analisado imediatamente e após 24h através da análise com espectroscopia FTIR; para dureza Knoop (DK, n=3), foram feitas 5 indentações no topo e na base de corpos de prova de 2 mm de espessura; para determinar a resistência à flexão (RF, n=10), o método de três pontos foi realizado em uma máquina universal de ensaios; a tensão de polimerização (TP) foi determinada pela fotopolimerização do material (1,0 mm de altura) entre hastes de polimetilmetacrilato em uma máquina de teste universal. A fotopolimerização foi realizada com um Valo Cordless LED (1.000 mW/cm2 x 20 s: 20J). Os resultados foram analisados por ANOVA e complementados pelo teste de Tukey (α=0,05). Resultados: os maiores valores de GC (imediato e 24h após) foram observados para as resinas VT e OP, seguidas de FZ, AU e ES. A resina FZ (superior e inferior) apresentou os maiores valores de DK, semelhante ao VT superior. As resinas AU, ES, OP e VT apresentaram DK estatisticamente diferente entre suas superfícies de topo e base. Os maiores valores de RF foram observados para FZ, seguido de OP/VT, ES e AU. Os maiores valores de TP foram observados para FZ, OP e VT. Conclusão: com base nos resultados, pode-se concluir que a resina Vittra APS com um novo sistema de polimerização apresenta desempenho satisfatório para os parâmetros avaliados.

Facetas diretas em resina composta utilizando o fluxo digital para planejamento: relato de caso / Direct facets in composite resin using digital flow for planning: case report / Facetas directas en resina compuesta utilizando flujo digital para planificación: reporte de caso

Introdução:O aprimoramento das resinas compostas nos últimosanos em associação com a difusão de informações nas redes sociais tornou as facetas diretas tratamentos populares na dentística restauradora. No entanto, são procedimentos que exigem ampla destreza manual e conhecimento técnico. O fluxo digital através doescaneamento, enceramento digital e prototipagem 3D para construção de guias tem se tornado uma excelente alternativa para aumentar a previsibilidade e aumentar a longevidade destes trabalhos. Objetivo:Descrever o protocolo de confecção de facetas diretas em resina composta, através de um relato de caso, utilizando como auxílio o planejamento digital para confecção de modelo 3D, guia de silicone e paredes palatinas. Descrição do Caso:Paciente do gênero masculino, 43 anos, queixava-se do formato dos seus dentes. Ao exame clínico percebeu-se desgaste dental nos incisivos centrais e linha do sorriso levemente invertida. Após duas sessões de clareamento de consultório com Peróxido de hidrogênio (35%) e mockup direto com resina composta, foi realizada a moldagem e escaneamento do modelo de gesso no laboratório. O enceramento digital foi aprovado, o modelo 3D foi impresso para confecção da guia de silicone. Com auxílio da guia foram executadas facetas diretas nos elementos 13, 12, 11, 21, 22 e 23. Conclusão:O fluxo digital pode ser uma alternativa viável para minimizar as falhas na confecção de facetas diretas em resina composta (AU).

Introduction:The improvement of composite resins in recent years, together with information disseminated on social media, has made direct veneers popular treatments in restorative dentistry. However, these procedures require significant manual dexterity and technical knowledge. Digital work flow using scanning, digital wax-up and 3D prototyping for the construction of guides has become an excellent alternative to increase predictability and the longevity of these procedures. Objective:Describe the manufacturing protocol for direct composite resin veneers, using a case report and digital to construct the 3D model, silicone guide and palatine walls. Case description:Male patient, 43 years old, complained of the shape of his teeth. Clinical examination revealed tooth wear on the central incisors and a slightly inverted smile line. After two whitening sessions with hydroigen peroxide (35%) and direct mockup with composite resin, the plaster model was molded and scanned in the laboratory. Digital wax-up was approved, and the 3D model was printed to manufacture the silicone guide. With the help of the guide, the direct veneers were applied to elements 13, 12, 11, 21, 22 and 23.Conclusions:Digital flow may be a feasible alternative to minimize manufacturing flaws in direct composite resin veneers (AU).

Introducción: La mejora de las resinas compuestas en los últimos años, y la difusión de información en las redes sociales, ha popularizado las facetas directas en los tratamientos en odontología restauradora. Sin embargo, son procedimientos que requieren demasiado destreza manual y conocimientos técnicos. El flujo digital usando escaneo, encerado digital y prototipado 3D para la construcción de guías se ha convertido en una excelente alternativa para aumentar la previsibilidad y la longevidad de estos procedimientos. Objetivo: Describir el protocolo para la realización de carillas directas en resina compuesta, a través de un reporte de caso, utilizando el planeo digital como ayuda para la realización de un modelo 3D, guía de silicona y paredes palatinas. Descripción del caso: Paciente masculino, 43 años, se quejó de la forma de sus dientes. El examen clínico reveló desgaste dental en los incisivos centrales y una línea de sonrisa levemente invertida. Después de dos sesiones de blanqueamiento en consultorio con peróxido de hidrógeno (35%) y maqueta directa con resina compuesta, el modelo de yeso fue moldeado y escaneado en el laboratorio. El encerado digital fue aprovado, el modelo 3D fue impreso para hacer la guía de silicona. Con la ayuda de la guía se realizaron carillas directas en los elementos 13, 12, 11, 21, 22 y 23. Conclusiones: El fluxo digital puede ser una alternativa viable para minimizar fallas en la fabricación de carillas directas en resina compuesta (AU).

Reabilitação estética e funcional com resina composta após trauma dentário: relato de caso / Aesthetic and functional rehabilitation with composite resin after dental trauma: case report

As lesões dentárias traumáticas são um problema de saúde pública mundial, dentre as quais a fratura dentária é a de maior ocorrência, envolvendo principalmente os dentes anteriores. A abordagem de grandes fraturas anteriores é um desafio para cirurgiões dentistas de qualquer nível pois, além da função, afetam diretamente a estética do paciente, fazendo-se necessário um planejamento que envolva diferentes especialidades na odontologia. Objetivo: Relatar um caso clínico de reabilitação funcional e estética de fratura dentária nos incisivos centrais superiores envolvendo tratamento endodôntico, instalação de pino de fibra de vidro e restauração direta em resina composta. Relato de Caso: O paciente de 17 anos sofreu fratura nos incisivos centrais superiores causada por uma queda de bicicleta. Devido à busca tardia por tratamento o elemento 21 foi diagnosticado com necrose pulpar e, portanto, foi submetido à tratamento endodôntico pela Técnica Crown Down e reabilitação com pino de fibra de vidro Splendor-SAP. Posteriormente, os elementos 11 e 21 foram restaurados com facetas diretas em resina composta pela técnica incremental. Conclusão: A reabilitação com instalação de pino de fibra de vidro associada à técnica de estratificação incremental em resina composta se mostra como uma boa opção para reabilitação estética pois permite dar forma anatômica ao dente com riqueza de detalhes na estratificação da dentina e esmalte, além de máxima preservação da estrutura dental. Os resultados obtidos reforçam o sucesso estético e funcional com significativo impacto na qualidade de vida do paciente(AU)

Traumatic dental injuries are a worldwide public health problem, among which dental fractures are the most frequent, mainly involving the anterior teeth. The approach of large anterior fractures is a challenge for dental surgeons of any level because, in addition to function, they directly affect the patient's esthetics, requiring a plan that involves different specialties in dentistry. Objective: Report a clinical case of functional and aesthetic rehabilitation of dental fractures in maxillary central incisors involving endodontic treatment, installation of a fiberglass post and direct restoration in composite resin. Case Report: The 17-year-old patient suffered a fracture in the upper central incisors caused by a fall from a bicycle. Due to the late search for treatment, element 21 was diagnosed with pulp necrosis and, therefore, underwent endodontic treatment using the Crown Down Technique and rehabilitation with a Splendor-SAP fiberglass pin. Later, elements 11 and 21 were restored with direct veneers in composite resin using the incremental technique. Conclusion: Rehabilitation with the installation of a fiberglass post associated with the incremental layering technique in composite resin is a good option for aesthetic rehabilitation as it allows the anatomical shape of the tooth with rich details in the layering of dentin and enamel, in addition to maximum preservation of the tooth structure. The results obtained reinforce the aesthetic and functional success with a significant impact on the patient's quality of life(AU)

In vitro comparison of marginal infiltration between a conventional resin and a bulk-fill resin, in the relocation of cervical margins technique / Comparación in vitro de la infiltración marginal entre una resina convencional y una resina bulk-fill, en la técnica de reubicación de márgenes cervicales

Introduction: Proximal lesions that exceed the cement enamel limit (ACE) under the gingival margin complicate impressions and the adhesive technique. Compare the magnitude of micro infiltration between conventional resin and bulk fill resin in the cervical margin relocation technique. Materials and Methods: 48 samples of human teeth re-ceived two preparations: occluso-mesial (OM) and occluso-distal (OD) under LAC; first they received the cervical margin relocation technique (RMC) with bulk fill and conventional resin; then restored with semi-direct resinous inlays. Sample analysis: immersion in 50% colloidal silver nitrate solution, 24 hours, 37°C and cut mesiodistally. Observed under a stereoscopic magnifying glass to assess dye penetration and digitally photographed, analyzed with "Image J" software. Results: Sample of 96 cavities in two groups of 48 units; control group restored with conventional resin with incremental technique and study group restored with bulk fill resin, mono-incremental technique. Probabilistic sampling. No statistically significant diffe-rences in percentage of microinfiltrated area between Filtek™ Z250™ and Filtek™ Bulk Fill™ (p-value= 0.68). Discussion: Various studies show that the presence of marginal microinfiltration exist independent of: restorative technique, consistency, adhesive mechanism and polyme-rization technique. The research carried out is no exception, observing a similar degree for both systems. Conclusions: Results allow us to conclude that conventi-onal resin and bulk fill resin did not show significant differences in microleakage percentages for the RMC technique. Outside the study framework, bulk fill resins would have comparative advantages; better behavior against light in depths greater than 2 mm, less sensitivity to the "C" factor, and less clinical time.

Introducción: Las lesiones proximales que superan el límite cemento esmalte (ACE) por debajo del margen gingival complican las impresiones y la técnica adhesiva. Comparar la magnitud de la microinfiltración entre la resina convencional y la resina de relleno en la técnica de reubicación del margen cervical. Materiales y Métodos: 48 muestras de dientes humanos recibieron dos preparaciones: ocluso-mesial (OM) y ocluso-distal (OD) bajo LAC, primero recibieron la técnica de reubicación del margen cervical (RMC) con relleno en bloque y resina convencional; luego restaurado con incrustaciones resinosas semidirectas. Análisis de la muestra: inmersión en solución de nitrato de plata coloidal al 50%, 24 horas, 37°C y corte mesiodistal. Observado bajo una lupa estereoscópica para evaluar la penetración del tinte y fotografiado digitalmente, analizado con el software "Image J". Resultados: Muestra de 96 cavidades en dos grupos de 48 unidades; grupo control restaurado con resina convencional con técnica incremental y grupo estudio restaurado con resina bulk fill, técnica mono-incremental. Muestreo probabilístico. No hubo diferencias estadísticamente significativas en el porcentaje de área microinfiltrada entre Filtek™ Z250™ y Filtek™ Bulk Fill™ (p-value = 0,68) Discusión: Diversos estudios evidencian presencia de microinfiltración marginal, independiente de técnica restauradora, consistencia, mecanismo adhesivo y técnica polimerizadora. La investigación realizada no es excepción, observándose grado similar para ambos sistemas. Conclusiones: Los resultados permiten concluir que resina convencional y resina bulk fill no presentaron diferencias significativas en porcentajes de microinfiltración para técnica RMC. Fuera del marco del estudio, resinas bulk fill tendrían ventajas comparativas; mejor comportamiento frente a la luz en profundidades superiores a 2 mm, menor sensibilidad al factor "C", y menor tiempo clínico.

Application of virtual training system for composite resin filling technique in undergraduate stomatology teaching / 中华医学教育探索杂志

Objective:To assess the influence of a virtual simulation-based training system for composite resin filling on the knowledge acquisition, skill development, and overall learning experience of undergraduate stomatology students.Methods:Forty-one undergraduate students of grade 2019 majoring in stomatology were divided into two groups for preclinical training before their internships: the experimental group used a virtual training system for composite resin filling, while the control group watched instructional videos of the procedure. The two groups were compared for their first performance in composite resin filling during the internships and teaching feedback. The t-test and chi-square test were conducted for data analysis using SPSS 20.0. Results:After repeatedly using the virtual training system for composite resin filling, the students in the experimental group were able to master the key operational points of the procedure, all achieving high scores (an average of 91.77 points) with an average time of 10.39 minutes. During the internship phase, the experimental group and control group showed significant differences in the accuracy rates of instrument selection (85.71% vs. 40.00%), adhesive applying (76.19% vs. 45.00%), and layered filling (100.00% vs. 75.00%; all P<0.05). All the students unanimously recognized the value of the virtual simulation system and expressed their willingness to use it for preclinical training before internships. Nineteen students (90.48%) were satisfied with the learning experience with the virtual simulation training system. Conclusions:The virtual simulation training system for composite resin filling can improve students' understanding and proficiency levels of the technique before clinical internships, facilitating a smoother transition to the internship phase.

Effects of applying procyanidins on the bond strength of bleached dentin to composite resin / 口腔疾病防治

Objective@#To study the influence of procyanidins on the bonding strength of dentin bleached by carbamide peroxide to composite resin.@*Methods @#By applying different treatments to dentin bonding interfaces, 120 human third molars were randomly divided into 12 groups (n = 10): W group (no bleaching+deionized water), Wa group (no bleaching+deionized water+aging), WT1 group (no bleaching+5% procyanidins for 1 min), WT1a group (no bleaching+5% procyanidins for 1 min+aging), WT2 group (no bleaching+5% procyanidins for 5 min), WT2a group (no bleaching+5% procyanidins for 5 min+aging), C group (carbamide peroxide+deionized water), Ca group (carbamide peroxide+deionized water+aging), CT1 group (carbamide peroxide+5% procyanidins for 1 min), CT1a group (carbamide peroxide+5% procyanidins for 1 min+aging), CT2 group (carbamide peroxide+5% procyanidins for 5 min), and CT2a group (carbamide peroxide+5% procyanidins for 5 min+aging). The bond strength to composite resin was measured by universal mechanical testing machine, microstructure and the nanoleakages were measured by scanning electron microscope immediately or after the thermal cycling aging test.@*Results@#The immediate bond strength of the bleached groups pretreated with procyanidins for 1 min (P<0.001) and 5 min (P<0.001) was higher than that of Group C, and the difference was statistically significant. Meanwhile, there was no statistically significant difference between Group CT1 and Group CT2 (P = 1.000). After the thermal cycles, the bond strength of each group declined. The differences between Group W and Group Wa (P<0.001) and Group C and Group Ca (P<0.001) were statistically significant, but no significant differences between Group CT1 and Group CT1a (P = 0.052) or Group CT2 and Group CT2a (P = 0.053) were found. The main effects of “aging” (P<0.001), “bleaching” (P<0.001) and “procyanidins” (P<0.001) and the second-order interaction effects of “bleaching * procyanidins” (P = 0.008), “bleaching * aging” (P = 0.024), and “aging * procyanidins” (P<0.001) were statistically significant. SEM observations showed that the hybrid layers in Groups C, CT1 and CT2 were not clear, and the hybrid layers in Groups Ca, CT1a and CT2a were partially destroyed and disintegrated. Under backscattering mode, it was observed that there were a large number of silver nitrate particles in the hybrid layer of Group Ca, and the residual silver ions in the hybrid layer of Groups CT1a and CT2a were decreased. @*Conclusion@# Pretreatment with 5% procyanidins for 1 min can improve the immediate bond strength of dentin bleached by carbamide peroxide to composite resin and maintain bonding durability.