Bleaching gel volume influences hydrogen peroxide diffusion, inflammation, and the presence of nitric oxide in the pulp tissue: in vitro and in vivo model.

OBJECTIVE: To assess whether bleaching gel volume influences chromatic changes, hydrogen peroxide (HP) diffusion, inflammation, and oxidative stress in the pulp tissue. METHODOLOGY: A total of 60 bovine teeth were divided into four groups, according to bleaching gel volume (n=15): without gel (WG); V30 (30 µL of 35% HP); V60 (60 µL); and V120 (120 µL). HP diffusion analysis was performed in the first session (T1). Chromatic changes (ΔE, ΔE00, and WID) were assessed after the first (T1), second (T2), third (T3) sessions, and 15 d (T4) after the end of treatment. Moreover, 20 rats were randomly divided into four groups (n=10) and their upper first molars were treated with different gel volumes: control (no treatment); V2 (2 µL of 17.5% HP); V4 (4 µL); and V8 (8 µL). After 24 h, rats were euthanized and the specimens processed for histological and immunohistochemical (nitric oxide synthase) evaluation. Data were analyzed using the Wilcoxon and Mann-Whitney tests (p<0.05). RESULTS: In vitro (bovine teeth), chromatic changes were not influenced by bleaching gel volume, showing similar values in all groups and sessions, except for the control group (p<0.05). The V120 group had the highest HP diffusion values (p<0.05). In vivo (pulp tissue), the V4 and V8 groups showed the highest inflammatory infiltrate in the pulp and significant oxidative stress (p<0.05). CONCLUSION: The adverse effects on the dental pulp related to HP diffusion, pulp inflammation, and oxidative stress depend on bleaching gel volume, while the bleaching effect is not proportional to the volume used.

Bleaching gel volume influences hydrogen peroxide diffusion, inflammation, and the presence of nitric oxide in the pulp tissue: in vitro and in vivo model

Abstract Objective To assess whether bleaching gel volume influences chromatic changes, hydrogen peroxide (HP) diffusion, inflammation, and oxidative stress in the pulp tissue. Methodology A total of 60 bovine teeth were divided into four groups, according to bleaching gel volume (n=15): without gel (WG); V30 (30 µL of 35% HP); V60 (60 µL); and V120 (120 μL). HP diffusion analysis was performed in the first session (T1). Chromatic changes (ΔE, ΔE00, and WID) were assessed after the first (T1), second (T2), third (T3) sessions, and 15 d (T4) after the end of treatment. Moreover, 20 rats were randomly divided into four groups (n=10) and their upper first molars were treated with different gel volumes: control (no treatment); V2 (2 μL of 17.5% HP); V4 (4 μL); and V8 (8 μL). After 24 h, rats were euthanized and the specimens processed for histological and immunohistochemical (nitric oxide synthase) evaluation. Data were analyzed using the Wilcoxon and Mann-Whitney tests (p<0.05). Results In vitro (bovine teeth), chromatic changes were not influenced by bleaching gel volume, showing similar values in all groups and sessions, except for the control group (p<0.05). The V120 group had the highest HP diffusion values (p<0.05). In vivo (pulp tissue), the V4 and V8 groups showed the highest inflammatory infiltrate in the pulp and significant oxidative stress (p<0.05). Conclusion The adverse effects on the dental pulp related to HP diffusion, pulp inflammation, and oxidative stress depend on bleaching gel volume, while the bleaching effect is not proportional to the volume used.

Photobiomodulation reduces inflammation but does not influence the hypoxia-inducible factor-1α in pulp tissue of rats after bleaching.

OBJECTIVES: To evaluate the influence of photobiomodulation with infrared laser (IRL) in the rat pulp tissue after bleaching, considering the immunolabeling of interleukin (IL)-23 and hypoxia-inducible factor (HIF)-1α. METHODOLOGY: The right and left molars of forty rats were divided into groups: Control - with placebo gel and Bleached - with 35% hydrogen peroxide (H2O2). Half of the rats received one IRL application on both sides, establishing a split-mouth design, which resulted in 4 groups with 20 hemi-maxillae each: Control, Bleach, IRL, and Bleached-IRL. Rats (n=10) from each group were euthanized, at 2- and 30-days mark, and the pulp tissue was evaluated using inflammation and immunolabeling scores. Wilcoxon and Mann-Whitney statistical tests were performed (p<0.05). RESULTS: At the 2-days mark, the Bleached group had severe inflammation and necrosis in the occlusal thirds of the pulp, and moderate to severe inflammation in cervical third, whereas the Bleached-IRL had mild to moderate inflammation (p<0.05). At the 30-days mark, there was no inflammation, but tertiary dentine formation in the bleached groups. Regarding IL-23, severe immunolabeling was observed in the Bleached group (p<0.05) at the 2-days mark; at the 30-days mark, there was a reduction in immunolabeling, in which the Bleached group had moderate and the Bleached-IRL group had mild immunolabeling (p>0.05). HIF-1α was more evident at the 2-days mark in the Bleached group, without significant difference with the Bleached-IRL (p>0.05). The difference was observed between the bleached and control groups, without immunolabeling (p<0.05); at the 30-days mark, the Bleached group had reduction in HIF-1α immunolabeling, while the Bleached-IRL had an increase; the difference remained between the bleached and the controls groups (p<0.05). CONCLUSION: Photobiomodulation using IRL minimized the inflammation and IL-23 immunolabeling in the pulp tissue of rats after dental bleaching, but did not influence significantly the HIF-1α immunolabeling.

Influence of low-level laser therapy on inflammation, collagen fiber maturation, and tertiary dentin deposition in the pulp of bleached teeth.

OBJECTIVES: We evaluated the effects of low-level laser therapy (LLLT) using an infrared laser (IRL) and a red laser (RL) on the pulp of molar teeth in rats after dental bleaching to assess inflammation, collagen fiber maturation, and tertiary dentin formation. MATERIALS AND METHODS: Eighty Wistar rats (Rattus norvegicus, albinus) were randomly divided into eight groups with 10 hemimaxillae in each of the following: control; bleached (Ble, 35% hydrogen peroxide [H2O2]); Ble-1IRL and Ble-1RL (one IRL [808 nm, 30 s, 3 J] or RL [660 nm, 15 s, 1.5 J] application immediately after H2O2); Ble-3IRL and Ble-3RL (three [immediately, 24 h, and 48 h] IRL or RL applications after H2O2); and 3IRL and 3RL (three IRL or RL applications without bleaching). The rats were euthanized after 2 and 30 days for histological evaluation of inflammation (hematoxylin-eosin) and maturation of collagen fibers (picrosirius red). Additionally, the dentin deposition in the specimens obtained at 30 days was quantified via microtomography of the pulp chamber volume. Statistical analyses were performed (P < 0.05). RESULTS: Initially, severe damages to the pulp were observed in the Ble and Ble-1RL groups. Ble-1IRL and Ble-3RL groups showed lower inflammation. The bleached groups had a greater amount of mature collagen fibers than the control group. The Ble-3IRL group had a greater number of immature fibers than the Ble group. At 30 days, there was an absence of inflammation and equal proportion of mature and immature collagen fibers. All bleached groups showed a reduction in the volume of the pulp chamber. CONCLUSION: Three consecutive applications of RL and one IRL application can minimize damage to the pulp of bleached teeth, whereas three IRL applications can minimize pulp fibrosis. However, LLLT did not prevent deposition of tertiary dentin. CLINICAL RELEVANCE: This study describes LLLT protocols capable of minimizing inflammation and maturation of collagen fibers in pulp tissue after dental bleaching. However, the protocols proved insufficient for reducing the formation of tertiary dentin in bleached teeth.

Influência da laserterapia de baixa intensidade no processo inflamatório e na imunomarcação da interleucina­23 e do fator indutor de hipóxia 1-alfa no tecido pulpar de dentes clareados / Influence of low-level laser therapy on the inflammatory process and immunolabeling of interleukin-23 and hypoxia-inducing factor 1-alpha in the pulp tissue of bleached teeth

Introdução: O uso do laser infravermelho (LIV) através da fotobiomodulação, tem demonstrado efeitos benéficos aos tecidos. Objetivos: Avaliar a influência do LIV sobre o processo inflamatório, por meio da imunomarcação da interleucina próinflamatória IL-23, e sobre a angiogênese, por meio da imunomarcação do fator induzível por hipóxia-1 alfa (HIF-1α), no tecido pulpar de dentes clareados. Materiais e métodos: Quarenta ratos Wistar foram distribuídos aleatoriamente em 4 grupos de 20 hemi-maxilas cada: Grupo Controle ­ recebeu o tratamento com o gel placebo; Grupo Cla - recebeu 30 minutos do gel clareador H2O2 a 35%; Grupo LIV ­ recebeu uma aplicação de LIV (808 nm, 30 segundos, 3J); Grupo Cla-LIV ­ imediatamente após a aplicação do H2O2 a 35%, recebeu uma aplicação de LIV, como descrito no grupo LIV. Após 2 e 30 dias (n = 10), os animais foram eutanasiados e as maxilas removidas e processadas para avaliação histológica (H.E.) e imunoistoquímica. Forma de análise: Os cortes teciduais seriados e com espessura de 5 µm corados em H.E. foram avaliados por escores atribuídos à inflamação, e a análise imunoistoquímica foi realizada através de escores atribuídos à imunomarcação. Os dados foram submetidos aos testes de Wilcoxon e Mann Whitney (p < 0,05). Resultados: Aos 2 dias, houve inflamação severa e necrose nos terços oclusal e médio do tecido pulpar no grupo Cla, diferente do grupo Cla-LIV com inflamação leve à moderada (p < 0,05). No terço cervical, houve inflamação moderada a severa no grupo Cla, e leve no grupo Cla-LIV (p < 0,05). Aos 30 dias, houve ausência de inflamação e os grupos clareados apresentaram deposição de dentina terciária. Em relação à IL-23, aos 2 dias foi observada imunomarcação severa no grupo Cla e moderada no grupo Cla-LIV (p < 0,05); aos 30 dias, houve redução na imunomarcação de IL-23 nos grupos clareados, onde o grupo Cla apresentou imunomarcação moderada, e o grupo Cla-LIV leve imunomarcação, sem diferença significante (p > 0,05). HIF-1α foi mais presente aos 2 dias no grupo Cla, sem diferença significativa com Cla-LIV (p > 0,05). Foi observada diferença entre os grupos clareados e seus respectivos controles, que não apresentaram imunomarcação (p < 0,05); aos 30 dias, o grupo Cla apresentou redução na imunomarcação para HIF-1α, enquanto o grupo Cla-LIV apresentou aumento da imunomarcação, mas a diferença permaneceu apenas entre os grupos clareados e seus controles (p > 0,05). Conclusão: O laser infravermelho minimizou o infiltrado inflamatório e a imunomarcação de IL-23 no tecido pulpar após a clareação dentária, mas não influenciou a imunomarcação de HIF-1α(AU)

Introduction: The use of infrared laser (IRL) through photobiomodulation has shown beneficial effects on tissues. Objectives: To evaluate the influence of LLL on the inflammatory process, by immunolabeling IL-23 pro-inflammatory interleukin, and on angiogenesis, by immunolabeling hif-1 alpha inducible factor (HIF-1α) in the pulp tissue of bleached teeth (HIF-1α). Materials and methods: Forty Wistar rats were randomly divided into 4 groups of 20 hemimaxilla each: control group - received treatment with placebo gel; Ble group - received 30 minutes of 35% H2O2 bleaching gel; IRL group - received one application of IRL (808 nm, 30 seconds, 3 J); Ble-IRL group - immediately after application of 35% H2O2, received an application of IRL, as described in the IRL group.. After 2 and 30 days (n = 10), the rats were euthanized and the jaws removed and processed for histological evaluation (H.E.) and immunohistochemistry. Form of analysis: Serial tissue sections with thickness of 5 µm stained in H.E. were evaluated by scores attributed to inflammation, and immunohistochemical analysis was performed by scores attributed to immunolabeling. The data were submitted to the Wilcoxon and Mann Whitney tests (P < 0.05). Results: At 2 days, there was a severe inflammation and the presence of necrosis in the occlusal and middle thirds of the pulp tissue in the Ble group, different compared to the Ble-IRL group with moderate to mild inflammation (P < 0.05). In the cervical third, there was moderate to severe inflammation in the Ble group, and mild in the Ble-IRL group (P < 0.05). At 30 days, there was absence of inflammation and bleached groups had an extensive deposition of tertiary dentin. Regarding IL-23, at 2 days was observed severe immunolabeling in the Ble group and moderate in the Ble-IRL group (P < 0.05); at 30 days, there was a reduction in IL-23 immunolabeling in the bleached groups, where Ble group had moderate immunolabeling, and Ble-IRL group had mild immunolabeling, without significant difference (P > 0.05). HIF-1α was more evident at 2 days in the Ble group, without significant difference with Ble-IRL (P > 0.05). The difference was observed between the bleached groups and their respective controls, which had no immunolabeling (P < 0.05); at 30 days, the Ble group had a reduction in HIF-1α immunolabeling, while the Ble-IRL group had an increase in immunolabeling from moderate to severe; however, the difference remained only between the bleached groups and their controls (P > 0.05). Conclusion: Infrared laser minimized the inflammatory infiltrate and IL-23 immunolabeling in the pulp tissue after dental bleaching, but did not influenced HIF-1α immunolabeling(AU)

Fechamento de diastema interincisal superior associado a dente supranumerário com intervenção ortodôntica: relato de caso clínico / Closure of superior intercernal diastema associated to supranumerary tooth with orthodontic intervention: clinical case / Cierre de diastema interincisal superior asociado a diente supernumerario con intervención ortodóntica: reporte de caso

A abordagem correta e precoce de paciente infantil frente a alteração de desenvolvimento como a presença de dentes supranumerários modificando a oclusão normal tem apresentado resultados satisfatórios e importantes para manter a função e estética da cavidade bucal. O objetivo deste trabalho é apresentar um caso clínico com tratamento multidisciplinar envolvendo dente supranumerário e diastema interincisal em paciente infantil. Paciente com 7 anos de idade, gênero masculino, compareceu a clínica de Odontopediatria da Faculdade Morgana Potrich, com a queixa de um dente da frente torto. O exame clínico e radiográfico revelou a presença de um mesiodens causando um diastema na região anterior da maxila, com evidentes transtornos estéticos. O plano de tratamento estabelecido foi a remoção cirúrgica do dente supranumerário e tratamento ortodôntico para fechamento do diastema, possibilitando um resultado funcional e estético satisfatório, melhorando a qualidade de vida deste paciente. Dessa forma, o tratamento em paciente com pouca idade propiciou uma intervenção simples e com boa resolubilidade, devolvendo sua autoestima e bem-estar no seu convívio social(AU)

The correct and early approach on children patient in relation to developmental alteration as the presence of supernumerary teeth modifying normal occlusion has presented satisfactory and important results to maintain the function and aesthetics of the oral cavity. The objective of this work is to present a clinical case with multidisciplinary treatment involving supernumerary tooth and interincisal diastema in a child patient. A 7-year-old male patient attended the pediatric dentistry clinic at Morgana Potrich College, complaining of a crooked front tooth. The clinical and radiographic examination revealed the presence of a mesiodens causing a diastema in the anterior region of the maxilla, causing evident aesthetic disorders. The treatment plan established was the surgical removal of the supernumerary tooth and orthodontic treatment for closure of the diastema, allowing a satisfactory functional and aesthetic result, improving the quality of life of this patient. Thus, the treatment in a patient at young age provided a simple and good solvability intervention, giving back his self-esteem and well-being in his social life(AU)

El abordaje correcto y temprano del paciente infantil frente a las alteraciones de desarrollo como la presencia de dientes supernumerarios que modifican la oclusión normal ha presentado resultados satisfactorios e importantes para mantener la función y estética de la cavidad oral. El objetivo de este trabajo es presentar un caso clínico con tratamiento multidisciplinar que involucra un diente supernumerario y diastema interincisal en un paciente infantil. Paciente con 7 años de edad, género masculino, compareció a la clínica de odontopediatría de la facultad Morgana Potrich, con queja de un diente al frente del otro. Al examen clínico y radiográfico se reveló la presencia de un mesiodens causando diastema en la región anterior del maxilar, con evidentes trastornos estéticos. El plan de tratamiento establecido fue la remoción quirúrgica del diente supernumerario y tratamiento ortodontico para cierre del diastema, posibilitando un resultado funcional y estético satisfactorio, mejorando la calidad de vida de este paciente. De esta forma, el tratamiento en un paciente con poca edad propicio una intervención simple y con buena resolución, devolviendo su autoestima y bienestar en su convivencia social(AU)