Desensitizing Agent Previously Applied During In-Office Bleaching: A Double-Blind Randomized Clinical Trial

Abstract Objective: To compare the clinical effect of two desensitizing agents used before the application of a bleaching gel based on 35% hydrogen peroxide (HP). Material and Methods: 30 patients were selected, and two desensitizing agents with different mechanisms of action were applied: Fluorine Neutral 2% (FN), which acts by blocking dentinal canaliculi while Potassium Nitrate 5% with 2% Sodium Fluoride (PN/SF) that acts in nerve transmission and blockade. Desensitizers were used before the application of 35% HP. For whitening, three clinical sessions were performed, with an interval of seven days, with three applications of the bleaching gel for 15 minutes, totaling 45 minutes/session. Tooth sensitivity (TS) was assessed with the numerical analog scale, and a spectrophotometer was used to obtain the color variation (ΔE). ΔE were submitted to ANOVA and Tukey test (p<0.05), and TS data were submitted to a two-way ANOVA analysis. Results: For sensitivity experience, the Tukey test indicated differences between PN/SF and the placebo I, but there was no statistically significant difference between FN and the placebo II. The TS was lower when the desensitizing gel was used during the bleaching procedure compared to after treatment, regardless of the desensitizing agents. Conclusion: PN/SF before in-office tooth bleaching can reduce TS intensity, and the use of desensitizing gel before bleaching did not affect the bleaching efficacy.

The in vitro effect of solutions with or without sugar in dental bleaching.

The interaction of bleaching technique (in-office or at-home) and solutions (deionized distilled water with and without sugar, red wine with and without sugar, coffee with and without sugar) on the effectiveness of in vitro dental bleaching was evaluated. Hydrogen peroxide (HP) 37.5% gel was used for in-office bleaching, 3 applications of 8 min each, 3 sessions with an interval of 7 days. At-home bleaching was performed with 10% Carbamide peroxide (CP), 2 h/day, for 30 days. The enamel vestibular surfaces (n = 72) were subjected daily to test solutions for 45 min, washed with distilled water for 5 min and stored in artificial saliva. The enamel color analysis was performed with a spectrophotometer through color variation (ΔE) and luminosity variation (ΔL). Roughness analysis was performed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Enamel composition was determined by energy dispersive X-ray spectrometry (EDS). The results were submitted to one-way analysis of variance (ANOVA) for ΔE, ΔL and EDS and two-way for AFM. For ΔE and ΔL there was no statistically significant difference. An increase in roughness was observed on the surface when exposed to a sugar-water solution for at-home bleaching and a lower concentration of Ca and P in the deionized water solution with sugar. Solutions containing or not sugar did not influence the bleaching potential, however the presence of sugar in the water solution increased the surface roughness with CP.

Surface roughness evaluation and whitening efficiency on tooth enamel after using whitening toothpaste: a randomized double-blinded study

The aim of this randomized double-blinded study was to evaluate the enamel surface roughness and color change after one month of whitening toothpaste use and the color stability obtained 1 month after its interruption. 30 volunteers were divided into 3 groups (n = 10) corresponding to the dentifrices: 1) Colgate Total 12 Clean Mint (TD) (Control), 2) Colgate Luminous White (LW) and 3) Sensodyne Whitening Extra Fresh (SB). The volunteers were impression with addition silicone to obtain an epoxy resin replica of the upper central incisor for the initial surface roughness evaluation using a profilometer and the initial color of the incisors and canines was evaluated with a spectrophotometer after one week of wash-out. After 1 month, the color of the central incisors and canines was measured again, and the volunteers were molded to obtain a second replica to the final roughness analysis. Data were submitted to ANOVA-one way (p≤0.05). The results showed that there was no statistical difference between the dentifrices for color difference and surface roughness for all the studied conditions. It was possible to conclude that the whitening dentifrices used in this study were not able to alter the initial color of the teeth and did not cause changes in the surface roughness of enamel.

Ellagic acid on the quality of the adhesive interface of class I composite resin restorations after aging

To evaluate the effect of ellagic acid on the inhibition of matrix metalloproteinase by analyzing the quality of the adhesive interface with bond strength measures in periods of 24 hours and six months of storage. Method: 40 healthy human third molars were prepared with class I cavities (5x4x3mm). The teeth were divided into four experimental groups: Group 1- without application of ellagic acid and storage time of 24 hours; Group 2- with ellagic acid/24 hours; G3- without ellagic acid/six months; Group 4- with ellagic acid/six months. Then, the cavities were restored with Single Bond Universal adhesive and Z350 composite resin, with and without the previous application of ellagic acid. Subsequently, hourglass-shaped specimens were obtained and subjected to the bond strength (BS) test (n = 10) in a universal testing machine. The bond test was performed after 24 hours and six months of storage. For the standard evaluation (n = 3) the samples were infiltrated with silver nitrate and placed in a developing solution for analysis in a Scanning Electron Microscope (SEM). The data obtained were analyzed with the Kruskal-Wallis non-parametric test, showing a statistically significant difference. Results: The highest bond strength values were found for the 24-hour groups followed by the groups with six months of storage. For nano-infiltration, groups G1 and G2 showed lower infiltration than groups G3 and G4. Conclusion: The previous application of ellagic acid did not affect the BS of the adhesive interface of the adhesive system analyzed, regardless of storage time.

Minimally invasive aesthetic treatment of white spots by dental fluorosis in children: case report

The presence of white spots due to dental fluorosis can cause aesthetic discomfort, being one of the factors for a search for dental treatment. Objective: Report a clinical case in which the aesthetic complaint was solved through the association of the dental bleaching to the microabrasion technique. Case report: Male patient, 13 years, attended to the Integrated Clinic of the School of Dentistry of the Federal University of Rio de Janeiro, with fluorosis, mainly in the antero-superior teeth and aesthetic complaint. Initially, it was made an immediate bleaching with hydrogen peroxide at 35%, in 3 sessions of 15 minutes each, to soften the disparity of shades between tooth-stain. The result was insufficient and the dental microabrasion technique was adopted. A pumice paste was applied together with gel of phosphoric acid at 37% under relative isolation, in a total of 8 applications (1 minute each). At the end of each application, it was made an abundant water washing, microengine mounted fine-grained disc polishing and topical application of neutral NaF2 in gel (4 minutes each application) to eliminate possible postoperative sensitivity. Conclusion: The dental bleaching and the microabrasion technique promoted satisfactory immediate clinical results that increased self-esteem of the patient in a minimally invasive way to dental structure.

Introdução: A presença de manchas brancas por fluorose dentária pode causar desconforto estético, sendo um dos fatores para busca de tratamento odontológico. Objetivo: Relatar um caso clínico em que a queixa estética foi resolvida através da associação do clareamento dentário à técnica de microabrasão. Relato do caso: Paciente do sexo masculino, 13 anos, compareceu a Clínica Integrada da Faculdade de Odontologia da UFRJ, com fluorose, principalmente nos dentes ântero-superiores e queixa estética. Inicialmente, realizou-se clareamento imediato com peróxido de hidrogênio a 35%, em 3 sessões de 15 minutos, para suavizar a disparidade de tons entre mancha-dente. O resultado obtido foi insuficiente e a técnica de microabrasão dentária foi adotada. Uma pasta de pedra pomes foi aplicada juntamente com gel de ácido fosfórico a 37% sob isolamento relativo, perfazendo um total de 8 aplicações (1 minuto cada). Ao final de cada aplicação, foi realizada lavagem abundante com água, polimento com disco de granulação fina montado em micromotor e aplicação tópica de NaF2 neutro em gel (4 minutos cada aplicação) para eliminar possível sensibilidade pós-operatória. Conclusão: O clareamento dentário e a técnica de microabrasão promoveram resultados clínicos imediatos satisfatórios que elevaram a autoestima do paciente, de maneira minimamente invasiva para estrutura dentária.

Correction to: The use of clays for chlorhexidine controlled release as a new perspective for longer durability of dentin adhesion.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Effect of tooth enamel staining by coffee consumption during at-home tooth bleaching with carbamide peroxide / Efeito da coloração do esmalte dentário pelo consumo de café durante o clareamento dentário caseiro com peróxido de carbamida

Introduction: Obtaining the result expected during tooth bleaching requires a correct diagnosis of the type of staining presented. The causes of tooth staining differ depending on the etiological factor. Objective: To assess the color change caused by the immersion of bovine teeth in coffee solution during at-home tooth bleaching using a 16% carbamide peroxide gel. Material and method: Thirty-three sound bovine teeth were assigned to three groups of eleven teeth each: 1 - Teeth bleached (TB) four hours per day for 21 days; 2 - TB four hours per day for 21 days and immersed in coffee solution immediately after tooth bleaching; 3 - TB four hours per day for 21 days and immersed in coffee solution four hours after the end of tooth bleaching. Immersed in coffee was performed for 15 minutes and tooth color was assessed before the start of the bleaching procedure and after 21 days with an intraoral spectrophotometer. Test Shapiro-Wilk was used to assess homoscedasticity and data were submitted to one-factor Analysis of Variance (ANOVA) and Tukey's test (p <0.05). Result: The color change observed in group 1 (5.76 ± 2.74)A was not statistically different from group 2 (8.83 ±5.11)A, which was immersed in coffee solution immediately after tooth bleaching, and from group 3, which was immersed in coffee solution four hours after tooth bleaching (8.20 ±3.71)A. Conclusion: Coffee did not interfere with the tooth bleaching results, regardless of the time after the procedure. Hence, diet restrictions are not necessary during tooth bleaching.

Introdução: A obtenção do resultado esperado durante o clareamento dental exige um diagnóstico correto do tipo de coloração apresentado. As causas da coloração dos dentes diferem dependendo do fator etiológico. Objetivo: Avaliar a mudança de cor causada pela imersão dos dentes bovinos na solução de café durante o clareamento dentário caseiro, utilizando gel de peróxido de carbamida a 16%. Material e método: Trinta e três dentes bovinos hígidos foram distribuídos em três grupos de onze dentes cada: 1 - Dentes clareados quatro horas por dia durante 21 dias; 2 - Dentes clareados quatro horas por dia durante 21 dias e imerso em solução de café imediatamente após o clareamento dentário; 3 - Dentes clareados quatro horas por dia durante 21 dias e imerso em solução de café quatro horas após o término do clareamento dentário. Imersão em café foi realizada durante 15 minutos e a cor dos dentes foi avaliada antes do início do procedimento do clareamento e após 21 dias com um espectrofotômetro intraoral. O teste Shapiro-Wilk foi utilizado para avaliar a homocedasticidade e os dados foram submetidos à análise de variância de um fator (ANOVA) e ao teste de Tukey (p <0,05). Resultado: A mudança de cor observada no grupo 1 (5,76 ± 2,74)A não foi estatisticamente diferente do grupo 2 (8,83 ± 5,11)A, imerso em solução de café imediatamente após o clareamento dentário, e do grupo 3, imerso em café quatro horas após o clareamento dental (8,20 ± 3,71). Conclusão: O café não interferiu nos resultados do clareamento dental, independentemente do tempo após o procedimento. Portanto, restrições alimentares não são necessárias durante o clareamento dental.

Effect of pigmenting agents on tooth enamel staining during immediate tooth whitening: an in vitro study / Efeito de agentes pigmentantes no manchamento do esmalte dental durante o clareamento dentário imediato: estudo in vitro

Introduction: Considering the increased search for esthetic procedures, questions emerge about the maintenance and regression of color, especially regarding the need to restrict dark foods during bleaching procedures or their influence on the stability and effectiveness of the treatment. Objective: To assess the influence of staining agents on tooth enamel during immediate bleaching treatment with 35% hydrogen peroxide. Material and method: Sixty bovine teeth were divided into six groups (G) (n=10): G1: distilled water (control); G2: coffee; G3: cola soft drink; G4: wine; G5: mate tea; and G6: industrialized açaí. The samples were subjected to immediate bleaching using 35% hydrogen peroxide for 21 days (three applications of 15 minutes per session, every seven days) and pigment immersion between each session for 15 minutes. The color was assessed before starting bleaching and after 21 days, using a spectrophotometer. The data obtained were subjected to one-way ANOVA and heteroscedasticity analysis by the Welch and Brown-Forsythe tests. The Tamhane test was used for group comparison. Result: The color change was visible to the naked eye, considering the mean ΔE in all groups tested was higher than 3.7. However, there was no statistical difference between the control group and the groups assessed. Conclusion: The contact of staining agents on bovine tooth enamel did not affect the final result of the immediate tooth bleaching.

Introdução: Com o aumento da procura por procedimentos estéticos, dúvidas surgem quanto à manutenção e regressão de cor, especialmente, no que tange a necessidade de restrição quanto à alimentos escuros durante o procedimento clareador ou a sua influência quanto à estabilidade e eficácia do tratamento. Objetivo: Avaliar a influência de agentes pigmentantes sobre o esmalte dental durante o tratamento clareador imediato com peróxido de hidrogênio a 35%. Material e método: 60 dentes bovinos foram divididos em 6 grupos (G) (n=10): G1: água destilada (controle), G2: café, G3: refrigerante à base de cola, G4: vinho, G5: chá-mate, e G6: açaí industrializado. As amostras foram submetidas ao clareamento imediato utilizando peróxido de hidrogênio a 35% durante 21 dias (3 aplicações de 15 minutos por sessão a cada 7 dias) e submetidas à imersão dos pigmentos entre cada sessão durante 15 minutos. A avaliação da cor foi realizada antes do inicio do clareamento e após 21 dias, mediante o uso do espectrofotômetro. Os dados obtidos foram submetidos ao ANOVA one-way e análise de heterocedasticidade pelos testes de Welch e Brown-Forsythe. O teste de Tamhane foi utilizado para a comparação entre os grupos. Resultado: Houve alteração de cor visível ao olho nu, uma vez que a média de ΔE em todos os grupos testados foi maior que 3,7. Contudo, não houve diferença estatística entre o grupo controle em relação aos grupos avaliados. Conclusão: O contato de agentes pigmentantes no esmalte dental bovino não influenciou o resultado final do clareamento dental imediato.

Effects of desensitizing dentifrices on the reduction of pain sensitivity caused by in-office dental whitening: a double-blind controlled clinical study.

Objective: The purpose of this study was to clinically evaluate the influence of desensitizing dentifrices applied through a plastic tray on reducing the pain sensitivity and color variation caused by in-office dental whitening and to evaluate differences among such dentifrices through a controlled double-blind clinical study. Materials and methods: A prospective study was conducted with 48 individuals between 18 and 30 years without gender distinction. For the dental whitening, 35% hydrogen peroxide was used in three clinical sessions. After each whitening session, the volunteers used a plastic tray containing one of the dentifrices (sucralose- S, sodium fluoride - SF, arginine and calcium carbonate - ACC, and 5% potassium nitrate - PN) for 4 hrs during the night. The evaluation of the sensitivity associated with the use of the plastic tray in each whitening session was performed using the analog numerical scale with scores from 0 to 10. The color variation (ΔE) was determined with a spectrophotometer. The pain sensitivity data were submitted to the multivariate analysis of variance with repeated measurements and a Lambda Wilks test (p<0.05). To analyze the color variation, a one-way ANOVA was applied (p<0.05). Results: The ACC and 5% NP groups showed a reduction in sensitivity in relation to the other groups (p<0.05). There was a reduction in sensitivity after placement of the tray with dentifrice. The color evaluation associated with the dentifrice showed no difference (p=0.9186). Conclusion: The use of desensitizing dentifrices with ACC or 5% NP in a plastic tray was effective for the reduction of pain sensitivity, and the use of a desensitizing dentifrice did not decrease the effectiveness of whitening.

Aesthetic recovery of the smile using a simple and effective application of prepolymerized composite veneers

Introduction: The prefabricated composite resin veneers are prepolymerized laminates of composite that appeared in the market to simplify the restorative procedure, reducing working time. They are extremely thin veneers fabricated in several sizes, which allows performing restorations with high aesthetic standard in anterior teeth using a minimally invasive technique. Objectives: This study aimed to show the use of prefabricated resin veneers in the re-anatomization and recovery of dental aesthetics of a young patient with history of fracture and darkening of anterior teeth after aesthetic periodontal surgery. Case report: The patient attended the clinic with a smile complaint and the clinical examination showed tooth 11 with cervical fracture, tooth 21 with color change and caries infiltration, and tooth 22 with inclination of the distal surface toward the palatal region. As treatment, was opted for the use of prefabricated composite resin veneers. Conclusion: The aesthetic results of this case were highly satisfactory, especially when compared with clinical time, cost, and the laboratory work of ceramic veneers, showing the quality and advantages of this material.

Introdução: As facetas pré-fabricadas de resina composta são laminados prépolimerizados de compósito que surgiram no mercado para simplificar o procedimento restaurador, reduzindo o tempo de trabalho. São facetas extremamente finas, fabricadas em diversos tamanhos, com as quais é possível realizar restaurações com alto padrão estético em dentes anteriores através de uma técnica minimamente invasiva. Objetivo: Esse trabalho teve como objetivo demonstrar o uso de facetas pré-fabricadas de resina na reanatomização e recuperação da estética dentária de um paciente jovem com histórico de fratura e escurecimento dos dentes anteriores, após cirurgia estética periodontal. Relato de caso: Paciente compareceu à clínica com queixa do sorriso e ao exame clínico, observou-se dente 11 com fratura cervical, dente 21 com alteração de cor e infiltração por cárie e dente 22 com inclinação da face distal para palatina. Como tratamento, foi optado pela utilização das facetas pré-fabricadas de resina composta. Conclusão: Os resultados estéticos deste caso foram altamente satisfatórios, principalmente quando comparados ao tempo clínico, custo e trabalho laboratorial de facetas de cerâmica, mostrando a qualidade e as vantagens desse material.

Aesthetic solution for ceramic restoration on cast metal core

Introduction: In order to satisfy the aesthetic desires of the population, by masking the restorations was the search for the evolution of restorative materials enabling the introduction of metal-free materials. But previous studies that have been made with metal structures often cannot be removed and therefore require devices that can be masked, because there is no desire for a total passage of light avoiding dim reflection of these funds. For these situations, you must opt for a ceramic system to provide a degree of opacity, without losing its characteristics of light transmission, reflectance and saturation. Case report: In case the patient had clinical a metal ceramic crown on the molten core element 21, it was confirmed radiographically the core could not be removed because it would fracture risk to the tooth. We chose to use an opaquer ceramic framework to prevent the passage of light over dark metal. The material of choice was zirconia ceramic by high flexural strength, allowing it to function as a framework for crowns. Conclusion: With the correct application of ceramic coverage on Caquetá noted that it is possible to mask the gray color of the metal through the knowledge of the optical material, the correct use of these properties, opacity and translucidus, and a close contact between dentists and prosthetic.

Introdução: A fim de satisfazer os anseios estéticos, da população, por mascarar as restaurações houve a busca pela evolução dos materiais restauradores possibilitando a introdução de materiais livres de metais. Porém trabalhos prévios que foram confeccionados com estruturas metálicas muitas vezes não podem ser removidos e, portanto, necessitam de artifícios para que possam ser mascarados, pois não há o desejo de uma total passagem de luz evitando a reflexão desses fundos escurecidos. Para estas situações, é necessário optar por um sistema cerâmico que apresente um grau de opacidade, sem perda de suas características de translucidez, refletância e saturação. Relato do caso: A paciente possuía uma coroa metalo-cerâmica sobre núcleo fundido no elemento 21, constatou-se radiograficamente que o núcleo não podia ser retirado, pois traria risco de fratura ao dente. Optou-se por utilizar uma cerâmica mais opaca de arcabouço para evitar a passagem de luz sobre o metal escurecido. O material de escolha foi à cerâmica de zircônia por apresentar alta resistência à flexão, permitindo que funcione como arcabouço para coroas unitárias. Conclusão: Com a correta aplicação de cerâmicas de cobertura sobre o casquete observou- se que é possível mascarar a cor acinzentada do metal através dos conhecimentos ópticos do material, a correta utilização dessas propriedades, opacidade e translucides, e um estreito contato entre dentista e protético.

Effects of primer excess on marginal adaptation, nanoleakage and bond strength of adhesive systems after aging

There is no consensus about the amount of primer inserted into the cavity. Aim: This study aimed to evaluate the effects of the amount of primer used on dentin microtensile bond strength (µTBs), nanoleakage and marginal sealing, following thermomechanical aging. Methods: 48 human third molars were selected and a box-shaped class I cavity was constructed to maintain enamel margins. Teeth were randomly assigned to 6 experimental groups (n=8). For the bonding protocols of the restorative procedure, two adhesive systems were used: three-step etch-and-rinse and two-step self-etch. Epoxy resin replicas of the occlusal surface were made, and the specimens were submitted to thermomechanical aging. Newer replicas were obtained after thermomechanical aging, and marginal adaptation was observed using SEM. To obtain sections (0.7 x 0.7 mm) for testing at a tension of 0.5 mm/min, teeth were serially sectioned in the buccallingual direction, parallel to the occlusal surface. Failure mode was then obtained. For nanoleakage evaluation, one section of each tooth was immersed in AgNO3 and evaluated using SEM. The µTBs data were submitted to a two-way ANOVA and Tukey's test (α= 0.05) Results: One drop of primer promoted higher µTBs than two or three drops. Besides, the three-step etch-and-rinse promoted greater µTBs (19.78) than the two-step self-etch adhesive (12.23). The increase in the amount of primer was directly proportional to the increase of infiltration. All groups exhibited more gaps after thermomechanical aging. Conclusion: Using an excess of primer is not recommended because it reduces the µTBs and forms an unsatisfactory hybrid layer

Rubber dam isolation--key to success in diastema closure technique with direct composite resin.

The use of direct composite resin for diastema closure has technique advantages, including that the restorative procedure can be carried out in one appointment at a reasonable cost and without the removal of sound tooth structure. The use of a rubber dam for closing diastemas with composite resin is of paramount importance as it prevents moisture contamination and ensures increased gingival retraction compared to other techniques. This provides better access to the cervical area of the tooth, facilitating proper placement of resin to recreate the natural anatomical contours and contact point. Thus, there is a more natural adaptation of the restoration to the gingival tissue, avoiding a space between the papilla and the restored tooth. To illustrate the advantages of this technique, two diastema closure cases are presented using direct composite resin with rubber dam isolation.