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Objective@#To investigate the efficacy of different bleaching methods on white-spot lesions of the enamel using optical coherence tomography and to evaluate its feasibility for monitoring the therapeutic effects on white-spot lesions. @*Methods@#Forty-eight sound premolars extracted for orthodontic reasons were selected and cut for 4 mm×4 mm×2 mm enamel blocks in buccal surfaces of the crowns. The samples were covered with acid-resistant varnish (except for the buccal surfaces) and immersed in demineralization solution for 18 days to establish the white-spot lesion models of the enamels. Samples were randomly divided into four groups (n=12). Group A was given demineralization only. Specimens in Group B, C and D were treated with 40% hydrogen peroxide, resin infiltration and 40% hydrogen peroxide combined with resin infiltration, respectively. Eight samples in each group were randomly selected. OCT was applied to observe the optical changes of the enamel surface and according to the OCT scanning results, the demineralization depth of enamel samples in each group was calculated. Then, the enamel blocks were embedded in epoxy resins, except the buccal surfaces, and measured for the microhardness values of the enamel surface by a microindentation hardness tester. Four samples in each group were cut longitudinally, and the ultrastructural changes of enamel samples in each group were observed by scanning electron microscope. @* Results@#OCT showed that the light scattering characteristics of enamel surface changed in all groups, and the bright layer was formed, but the thickness of bright layer in Group C and D was significantly lower than that in Group A and B (P<0.05). The microhardness values (kg/mm2) of the samples in Group A-D were (214.99±31.70), (250.66±33.64), (312.42±18.01) and(286.53±26.65), respectively. The microhardness of enamel surfaces in Group C and D was significantly higher than that in Group A and B (P<0.05), and the ultrastructure of enamel surfaces in Group C and D were more flat and dense in SEM observation (P<0.05). @*Conclusion@#The methods of resin infiltration therapy or 40% hydrogen peroxide combined with resin infiltration could effectively improve white-spot lesions of the enamel and the non-invasive OCT can be used as a better evaluation method for the diagnosis and treatment of white-spot lesions of the enamel.
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Bleaching of vital teeth is a very common practice nowadays prompted by high esthetic demands of patients. But bleaching agents are known to cause some transient damage to enamel microstructure, so the need arises to determine the effect of bleaching agents on the mineral content of enamel. Aim: To evaluate mineral loss from enamel using in-office bleaching agent Hydrogen Peroxide and the effect of LED and Laser activated bleaching agent on mineral loss from enamel. Methods: Forty human premolar crowns were divided into buccal and lingual specimens and 80 blocks of 4x4x3mm each were obtained. Samples were randomly divided into four groups of twenty each depending upon the beaching treatment and activation method. Group I – Hydrogen Peroxide without additional activation, Group II – Hydrogen Peroxide with additional activation by Diode Laser, Group III – Hydrogen Peroxide with additional activation by LED Light and Group IV – Control group. Amount of calcium and Phosphate loss was calculated using atomic absorption spectrophotometry. Results: Results showed that bleaching with hydrogen peroxide leads to calcium and phosphate loss from enamel with additional activation resulting in higher amounts of mineral loss especially with Laser activation. Conclusion: Bleaching agents result in calcium and phosphate loss from enamel with significantly high loss of minerals due to additional activation by Laser and LED Light. Therefore bleaching procedures must be followed by remineralization treatments to prevent damage to enamel.
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Resumen Objetivo: Analizar los cambios en la molécula de fosfato v1 en el esmalte dental luego de la aplicación de blanqueamiento dental de oficina a diferentes concentraciones y tipo de activación. Material y métodos: 30 piezas dentales humanas recién extraídas, libres de caries y pigmentaciones fueron distribuidas aleatoriamente en tres grupos experimentales. Los blanqueamientos dentales utilizados en cada grupo experimental fueron Zoom! WhiteSpeed (grupo 1), Pola Office con fotoactivación (grupo 2) y Pola Office sin fotoactivación (grupo 3). Los agentes blanqueadores fueron aplicados de acuerdo con las instrucciones del fabricante, con dos aplicaciones en la primera sesión y una aplicación en la segunda sesión. Se midió la concentración de la molécula de fosfato v1 en el esmalte dental previo al tratamiento y después de cada sesión de blanqueamiento por medio de espectroscopia Raman. Se realizó el análisis de varianza ANOVA para mediciones repetitivas (p ≤ 0.05) y test de Bonferroni para comparaciones entre sesiones de tratamiento y semana control. Resultados: Los tres blanqueamientos de oficina utilizados causaron un incremento en la concentración de la molécula de fosfato v1 durante el proceso de blanqueamiento (p ≤ 0.05). Pola Office, con ambos tipos de activación, causó un aumento significativo en fosfato durante todo el tratamiento. Zoom! WhiteSpeed mostró un incremento significativo respecto a la semana control, pero no entre la primera y segunda sesión (p ≤ 0.05). Conclusiones: Dentro de las limitaciones de este estudio es posible concluir que los tres blanqueamientos de oficina estudiados provocaron un aumento de la molécula fosfato v1. El tipo de activación no causó una diferencia significativa.
Abstract Objective: To analyze changes in phosphate molecules in dental enamel after application of in-office dental bleach at different concentrations and type of activation. Material and methods: 30 recently extracted, human teeth free of caries and pigmentations were randomly distributed into three experimental groups. Tooth whitening materials used in each experimental group were Zoom! WhiteSpeed (group 1), Pola Office with light-activation (group 2) and Pola Office without light activation (group 3). Bleaching agents were applied according to manufacturer's instructions; two applications on the first sessions and one application in the second session. With Raman spectroscopy phosphate v1 molecule concentration was measured in tooth enamel before treatment and after each bleaching session. ANOVA variance analysis was used for repetitive measurements (p ≤ 0.05); Bonferroni post hoc test was used for comparisons between treatment sessions and control week. Results: All three in-office bleachers elicited increase in phosphate v1 molecule concentration during bleaching process (p ≤ 0.05), Pola Office, with both types of activation caused significant phosphate increase during the whole treatment. Zoom! WhiteSpeed showed significant increment with respect to control week, but did not show increase between first and second session (p ≤ 0.05). Conclusions: Within the scope of this study's limitations, it is possible to conclude that all three studied in-office bleaching agents increased phosphate v1 molecule. Activation type did not elicit significant difference.
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Abstract Hydrogen peroxide (H2O2) penetrates into the dental hard tissues causing color alteration but also alterations in pulpal tissues. Hard-tissue penetration, color alteration and the pulp response alterations were evaluated for two in-office bleaching protocols with H2O2. For trans-enamel/dentin penetration and color alteration, discs of bovine teeth were attached to an artificial pulp chamber and bleached according to the groups: BLU (20% H2O2 - 1x50 min, Whiteness HP Blue); MAX (35% H2O2 - 3x15 min, Whiteness HP Maxx); Control (1x50 min, placebo). Trans-enamel/dentin penetration was quantified based on the reaction of H2O2 with leucocrystal violet and the color analyzed by CIELab System. Twenty Wistar rats were divided into two groups (BLU and MAX) and their maxillary right molars were treated according to the same protocols of the in vitro study; the maxillary left molars were used as controls. After 2 days, the animals were killed and their maxillae were examined by light microscopy. The inflammation of pulp tissue was scored according to the inflammatory infiltrate (1, absent; 2, mild; 3, moderate; 4, severe/necrosis). Data were analyzed by statistical tests (α=0.05). MAX showed higher trans-enamel/dentinal penetration of H2O2 (p<0.05). The color alteration was similar for both groups (p>0.05), and different when compared to Control group (p<0.05). MAX showed severe inflammation in the upper thirds of the coronal pulp, and BLU showed moderate inflammation (p<0.05). In-office bleaching protocols using lower concentrations of hydrogen peroxide should be preferred due to their reduced trans-enamel/dentinal penetration since they cause less pulp damage and provide same bleaching efficiency.
Resumo O peróxido de hidrogênio (H2O2) é capaz de penetrar pelos tecidos dentários, alterando a coloração destes, e causar danos a polpa. Este estudo avaliou a penetração por esmalte e dentina, a alteração de cor e a reposta tecidual pulpar, provocadas pelo uso de duas concentrações de H2O2 em protocolos de clareação dentária de consultório. Discos de dentes bovinos em câmaras pulpares artificiais receberam géis clareadores para avaliação da penetração por esmalte e dentina e da alteração de cor, formando os grupos: BLU (H2O2 20% - 1x50 min, Whiteness HP Blue); MAX (H2O2 35% - 3x15 min, Whiteness HP Maxx); e Controle (gel placebo - 1x50 min). A penetração por esmalte e dentina foi quantificada baseada na reação do H2O2 com o corante violeta leucocristal, e a alteração de cor foi analisada pelo sistema CIELab. Vinte ratos Wistar foram divididos em dois grupos (BLU e MAX), e tiveram os molares direito superiores tratados com os mesmos protocolos do estudo in vitro; os molares superiores do lado esquerdo serviram de controle. Após 2 dias, os animais foram eutanasiados e as maxilas examinadas por microscopia de luz. Foram atribuídos escores ao infiltrado inflamatório (1, ausente; 2, leve; 3, moderado; 4 severo ou necrose). Os dados foram submetidos a testes estatísticos (=0,05). O grupo MAX apresentou maior penetração de H2O2 por esmalte e dentina (p<0,05). A alteração de cor foi semelhante nos grupos clareados (p>0,05), mas diferente quando comparados grupos clareados com controle (p<0,05). MAX apresentou inflamação severa nos terços superiores da polpa coronária, e BLU apresentou inflamação moderada (p<0,05). Assim, protocolo para procedimento clareador de consultório utilizando baixas concentrações de H2O2 deve ser de escolha na clínica, por reduzir a penetração por esmalte e dentina, causando menos danos à polpa, e proporcionar mesma eficiência clareadora.
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Animales , Masculino , Bovinos , Ratas , Color , Blanqueamiento de Dientes , Ratas WistarRESUMEN
OBJECTIVES: This clinical study evaluated the effect of light activation on the whitening efficacy and safety of in-office bleaching system containing 15% hydrogen peroxide gel. MATERIALS AND METHODS: Thirty-three volunteers were randomly treated with (n = 17, experimental group) or without light activation (n = 16, control group), using Zoom2 white gel (15% H2O2, Discus Dental) for a total treatment time of 45 min. Visual and instrumental color measurements were obtained using Vitapan Classical shade guide and Shadepilot (DeguDent) at screening test, after bleaching, and 1 month and 3 month after bleaching. Data were analyzed using t-test, repeated measure ANOVA, and chi-squared test. RESULTS: Zoom2 white gel produced significant shade changes in both experimental and control group when pre-treatment shade was compared with that after bleaching. However, shade difference between two groups was not statistically significant (p > 0.05). Tooth shade relapse was not detected at 3 months after bleaching. The incidence of transient tooth sensitivity was 39.4%, with being no differences between two groups. CONCLUSIONS: The application of light activation with Zoom2 white gel system neither achieved additional whitening effects nor showed more detrimental influences.
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Humanos , Hidrógeno , Peróxido de Hidrógeno , Hipersensibilidad , Incidencia , Luz , Tamizaje Masivo , Recurrencia , Diente , Blanqueamiento de DientesRESUMEN
Son varias las fuentes de energía utilizadas para acelerar la descomposición del peróxido de hidrógeno durante el blanqueamiento realizado en el consultorio. Durante su aplicación, los sistemas de blanqueamiento dental que utilizan fuentes de energía, aumentan la temperatura de los tejidos dentarios. Existen evidencias de que el aumento de la temperatura intracámara pulpar puede causar daño a este tejido. Este trabajo tuvo por objetivo presentar a través de una revisión de la literatura los diferentes tipos de luz utilizados para blanqueamiento y el calentamiento intracámara pulpar generado por estos. El aumento de temperatura intracámara pulpar crítico es considerado de 5,5º C. En estudios in vitro varios son los sistemas y combinaciones de tiempo que llegan o pasan esta temperatura. Antes de la utilización de estos sistemas el odontólogo debe conocer los riesgos existentes y leer las instrucciones de los fabricantes
To accelerate the decomposition of hydrogen peroxide during the in-office bleaching process, various energy sources can be used. During the application of these energy systems, an increase of temperature in teeth tissue has been reported. The temperature rise in the pulp might be harmful to this tissue. The objective of this work was to present through a literature review the different lights for an in-office bleaching and the resultant intrapulpal temperature rise produced by these lights. The critical temperature rise in pulp chamber is considered to be 5.5º C. On in vitro studies there are many systems and time combinations that achieved or passed this critical limit. Before the use of any energy source for the in- office bleaching, the dentist should be concerned about the existing risk and must read the manufacturer's instructions
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Humanos , Masculino , Femenino , Luz , Blanqueamiento de Dientes , OdontologíaRESUMEN
O objetivo deste trabalho clínico foi avaliar a sensibilidade e a alteração de cor dos elementos dentais, quando submetidos ao clareamento de consultório, com um produto à base de peróxido de hidrogênio a 35%, sem fotoativação. Fizeram parte dessa pesquisa clínica 22 voluntários. Os fatores em estudo foram Tratamento Clareador em dois níveis (gel experimental a base de peróxido de hidrogênio a 35% e placebo) e Tipo de Dente em dois níveis (incisivos e caninos). Os voluntários tiveram suas hemiarcadas superiores direita e esquerda submetidas ao tratamento placebo ou experimental, caracterizando um delineamento tipo split-mouth, ou de boca dividida. Foram realizadas quatro sessões de clareamento, com uma semana de intervalo entre as sessões. A mensuração da variável alteração da cor foi realizada, pelo método visual, previamente ao início do experimento e após a aplicação dos materiais; e da variável sensibilidade durante e após a aplicação da técnica clareadora. De acordo com os fatores clareamento e sessões de clareamento em estudo; assim como com as variáveis de resposta cor e sensibilidade, foram aplicados os testes não paramétricos do sinal, de Mann-Whitney e de Kruskal-Wallis, ao nível de significância de 5%. Foi observado que após a primeira, segunda e terceira sessões, os dentes foram clareados quando tratados com o agente experimental a base de peróxido de hidrogênio a 35%; para a variável sensibilidade, foi verificado após a terceira e quarta sessões de clareamento com o agente experimental peróxido de hidrogênio a 35%, a presença de sensibilidade estatisticamente superior ao tratamento com o produto placebo, em todos os tempos de avaliação. Concluiu-se que a alteração de cor e a sensibilidade dental foram provocadas pelo gel clareado.
This clinical research will be evaluating the sensitivity, the alteration and stability colors dental, on patients when submitted to in-office dental bleaching with 35% HP, without light-activation sources. According to pre-established criteria, 20 patients will be selected. The factors will be Bleaching Procedures in two levels (experimental gel based on 35% HP and placebo) and Teeth in two levels (incisors and canines). According to a randomly draw, the volunteers will be theirs superior hemiarches, right and left, submitted to placebo treatment or experimental treatment, characterizing a split-mouth design. It will be carry out four sessions of the bleaching procedures with a one week break between sessions. The response variables analysed at each session will be: Dental Color, measured previously and immediately after application of the materials and removal of absolute isolation; and Sensitivity, measured during and till 24 hours after the aplication of the bleaching procedures. The results obtained will be submitted to appropriate Statistical analysis. It was observed that after the first, second and third sessions, the teeth were bleached when treated with the experimental agent on hydrogen peroxide 35%. The variable sensitivity was observed after the third and fourth sessions of bleaching agent experimental hydrogen peroxide 35%. It was concluded that the color change and tooth sensitivity are varied depending on the whitening gel.
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Humanos , Adolescente , Adulto Joven , Color , Sensibilidad de la Dentina , Peróxido de Hidrógeno , Blanqueamiento de DientesRESUMEN
This study investigated the clinical effectiveness and safety of sealed bleaching compared to conventional in-office bleaching using a randomized clinical trial of split arch design. Ten participants received a chairside bleaching treatment on the upper anterior teeth, and each side was randomly designated as sealed or control side. A mixture of Brite powder (PacDent, Walnut, USA), 3% hydrogen peroxide and carbamide peroxide (KoolWhite, PacDent, Walnut, USA) were used as bleaching agent. The control side was unwrapped and the experimental side was covered with a linear low density polyethylene (LLDPE) wrap for sealed bleaching. The bleaching gel was light activated for 1 hour. The tooth shades were evaluated before treatment, after treatment, and at one week check up by means of a visual shade (VS) assessment using a value oriented shade guide and a computer assisted shade assessment using a spectrophotometer (SP). The data were analyzed by paired t-test. In the control and sealed groups, the visual shade scores after bleaching treatment and at check up showed statistically significant difference from the preoperative shade scores (p < .05). The shade scores of the sealed group were significantly lighter than the control immediately after bleaching and at the check-up appointment (p < 0.05). Compared to prebleaching status, the DeltaE values at post-bleaching condition were 4.35 +/- 1.38 and 5.08 +/- 1.34 for the control and sealed groups, respectively. The DeltaE values at check up were 3.73 +/- 1.95 and 4.38 +/- 2.08 for the control and sealed groups. DeltaE values were greater for the sealed group both after bleaching (p < .05) and at check up (p < .05). In conclusion, both DeltaE and shade score changes were greater for the sealed bleaching group than the conventional bleaching group, effectively demonstrating the improvement of effectiveness through sealing.