One-year clinical observation of the effect of internal bleaching on pulpless discolored teeth / 华西口腔医学杂志

OBJECTIVES@#This study aimed to observe the color rebound and rebound rates of non-pulp discolored teeth within 1 year after routine internal bleaching to guide clinical practice and prompt prognosis.@*METHODS@#In this work, the efficacy of bleaching was observed in 20 patients. The color of discolored teeth was measured by using a computerized colorimeter before bleaching; immediately after bleaching; and at the 1st, 3rd, 6th, 9th, and 12th months after bleaching. The L*, a*, and b* values of the color of cervical, mesial, and incisal parts of the teeth were obtained, and the color change amounts ΔE*, ΔL*, Δa*, and Δb* were calculated. The overall rebound rate (P*) and the color rebound velocity (V*) were also analyzed over time.@*RESULTS@#In 20 patients following treatment, the average ΔE* of tooth color change was 14.99. After bleaching, the neck and middle of the teeth ΔE* and ΔL* decreased in the 1st, 3rd, 6th, 9th, and 12th months, and the differences were statistically significant. Meanwhile, from the 9th month after bleaching, the rebound speed was lower than that in the 1st month, and the difference was statistically significant. The incisal end of the tooth ΔE* and ΔL* decreased in the 6th, 9th, and 12th months after bleaching, and the differences were statistically significant. No significant difference was found in the rebound speed between time points. However, this rate settled after the 9th month, with an average color rebound rate of 30.11% in 20 patients.@*CONCLUSIONS@#The results indicated that internal bleaching could cause a noticeable color change on pulpless teeth. The color rebound after bleaching was mainly caused by lightness (L*), which gradually decreased with time, and it was slightly related to a* and b*. The color of the teeth after internal bleaching rebounded to a certain extent with time, but the color rebound speed became stable from the 9th month. Clinically, secondary internal bleaching can be considered at this time according to whether the colors of the affected tooth and the adjacent tooth are coordinated and depending on the patient's needs.

Effect of bleaching protocols on surface roughness and color change of high- and low-viscosity bulk-fill composite resins / Efeito de protocolos clareadores na rugosidade de superfície e alteração de cor de resinas compostas bulk-fill de alta e baixa viscosidade

ABSTRACT The aim of this in vitro study was to evaluate the effect of bleaching protocols on the surface roughness (Ra), color change and surface micromorphology of a low-viscosity bulk-fill composite (Filtek Bulk Fill Flow, 3M ESPE), a highviscosity bulk-fill composite (Filtek Bulk Fill, 3M ESPE) and a conventional nanoparticulate composite resin (control) (Filtek Z350 XT, 3M ESPE). Forty samples of each composite (disks 5 mm in diameter and 2 mm thick) were randomly divided into four groups (n=10), according to bleaching protocol: a) 10% carbamide peroxide gel (Opalescence, Ultradent Products) (2 h/ day, for 14 days); b) 40% hydrogen peroxide gel (Opalescence Boost, Ultradent Products) (three bleaching sessions, once a week, 45 min/session); c) whitening rinse (Listerine Whitening Extreme, Johnson & Johnson) (2 min/day, for 14 days); and d) distilled water (control). The samples were submitted to triplicate readings (Ra and color [CIELAB parameters]) before and after contact with bleaching protocols. Micromorphology was analyzed in a scanning electron microscope (SEM). Ra and color parameters (ΔL, Δa, Δb and ΔE) were analyzed by generalized linear models (α=0.05). The Ra of the high-viscosity bulk-fill was significantly higher than that of the other composites (p<0.05). Ra increased significantly (p<0.05) and surface became more irregular (SEM analysis) in all the composite resins, regardless of the bleaching protocol (p<0.05). The high-viscosity bulk-fill composite resin group had significantly lower ΔE (p<0.05) than the nanoparticulate composite resin group immersed in distilled water. It was concluded that the characteristics of each resin significantly influenced the Ra more than the bleaching protocol. The high-viscosity bulk-fill resin presented minor color change.

RESUMO Este estudo in vitro teve objetivo de avaliar o efeito de protocolos clareadores sobre a rugosidade de superfície (Ra), alteração de cor e micromorfologia de resina bulk-fill de baixa viscosidade (Filtek Bulk Fill Flow, 3M ESPE), alta viscosidade (Filtek Bulk Fill, 3M ESPE) e de uma resina composta nanoparticulada (controle) (Filtek Z350 XT, 3M ESPE). Quarenta amostras de cada resin composta (discos de 5 mm de diâmetro e 2 mm de espessura) foram aleatoriamente divididas em quatro grupos , de acordo com protocolo clareador (n=10): a) Gel de peróxido de carbamida (Opalescence, Ultradent Products) (2 horas/dia, por 14 dias); b) Gel de peróxido de hidrogênio (Opalescence Boost, Ultradent Products) (3 sessões de clareamento, uma por semana, 45 min/sessão); enxaguatório clareador (Listerine Whitening Extreme, Johnson & Johnson) (2 min/dia, por 14 dias); d) água destilada (controle). As amostras foram submetidas a leituras, em triplicata (Ra e cor (parâmetros CIELab) antes e depois do contato com os protocolos clareadores. A micromorfologia de superfície foi conduzida em microscópio eletrônico de varredura (MEV). Ra e parâmetros de cor (ΔL, Δa, Δb e ΔE) foram analisados por modelos lineares generalizados (α=0.05). A Ra da resina bulk-fill de alta viscosidade foi significantemente superior do que para os outros compósitos (pp<0.05). A Ra aumentou significantemente (p<0.05) e a superfície ficou mais irregular (MEV) para todos os compósitos, independente do protocolo clareador (pp<0,05). A resina bulk-fill de alta viscosidade obteve menor ΔE (pp<0.05) do que a resina composta nanoparticulada, imersa em água destilada. Pode-se concluir que as características de cada resina composta influenciaram de forma mais significativa a Ra do que o protocolo clareador. A resina bulk fill de alta viscosidade apresentou menor alteração de cor.

Efectividad del Oleozón® en el tratamiento de pacientes con discromía dental / Effectiveness of Oleozon® in the treatment of patients with dental dischromya

Se realizó un estudio cuasiexperimental, de intervención terapéutica, para evaluar la efectividad del Oleozón® tópico y la luz halógena como fuente de luz azul y calor en el tratamiento de 52 pacientes con discromías dentales, atendidos en el Policlínico Docente Ramón López Peña del municipio de Santiago de Cuba, desde junio del 2015 hasta marzo del 2016. Se conformaron 2 grupos: de estudio (pares), a los cuales se les aplicó Oleozón® tópico; de control (impares), quienes recibieron tratamiento convencional con peróxido de hidrógeno. Al culminar las sesiones, ambos medicamentos resultaron efectivos en 100 por ciento de los afectados, aunque los del segundo grupo evolucionaron más rápidamente que los del primero. Se demostró que el Oleozón® tópico y la luz halógena son efectivos en el tratamiento de pacientes con discromías dentales y no provocan efectos adversos en los dientes tratados

A quasi-experiment, of therapeutic intervention study was carried out, to evaluate the effectiveness of the topic Oleozon® and the halogen light as source of blue light and heat in the treatment of 52 patients with dental dischromyas, assisted in Ramón López Peña Teaching Polyclinic in Santiago de Cuba from June, 2015 to March, 2016. Two groups were conformed: a study group (pairs), to whom topic Oleozon® was applied; a control group (odd numbers) who received conventional treatment with peroxide of hydrogen. When culminating the sessions, both medications were effective in 100 percent of the affected patients, although those of the second group evolved more quickly than those of the first one. It was demonstrated that topic Oleozon® and halogen light are effective in the treatment of patients with dental dischromyas and they cause no adverse effects in the treated teeth

Dental bleaching with ozone: effects on color and enamel microhardness / Clareamento dental com ozônio: efeitos na cor e na microdureza do esmalte

The aim of this in vitro study was to evaluate the effects of dentalbleaching with ozone (O3) on color change and enamelmicrohardness. Enamel blocks (3 x 3 x 3mm) were randomlydistributed for treatments (n=10). Color change (ΔE) and Knoopmicrohardness of the enamel blocks were evaluated before andafter the following treatments: C – deionized water (control); HP– 37.5% hydrogen peroxide (Pola Office+/ SDI); PLA – placebogel; O3– ozone; and O2– oxygen. Four 8-minute applicationswere used for HP and PLA, and one 19-minute application for O3and O2.One-way ANOVA revealed that ΔE was not significantlyinfluenced by the treatment (p = 0.112). For the treatments withHP, PLA, O3 and O2, ΔE was greater than 3.3. The paired t testshowed significant decrease in microhardness after treatments (p< 0.001) but no significant difference between treatments(ANOVA; p = 0.313). Dental bleaching treatments with O3, HP,O2and PLA induced enamel color changes that may be clinicallydiscernible, although enamel microhardeness decreased.

O objetivo deste estudo in vitro foi avaliar os efeitos doclareamento dental com ozônio (O3) quanto à alteração de core microdureza do esmalte. Blocos de esmalte (3 x 3 x 3mm)foram aleatoriamente distribuídos entre os tratamentos(n=10). Alteração de cor (ΔE) e microdureza Knoop foramavaliados antes e após cada um dos seguintes tratamentos: C– água deionizada (controle); PH – peróxido de hidrogênio a37,5% (Pola Office+/ SDI); PLA – gel placebo; O3– ozônio;O2– oxigênio. Quatro aplicações de PH e PLA foramrealizadas por 8 minutos cada e uma aplicação de O3e O2foram realizados por 19 minutos em cada bloco de esmalte.ANOVA a um critério mostrou que os valores de ΔE não foramsignificativamente influenciados pelo tratamento (p = 0,112).Para os tratamentos com PH, PLA, O3 e O2, o ΔE foi maior que3,3. O teste t pareado mostrou diminução significativa dosvalores de microdureza no final do tratamento quandocomparado com o tempo baseline (p < 0,001), mas não houvediferença significativa entre os tratamentos (ANOVA; p =0,313). O tratamento com O3, PH, O2e PLA levou a alteraçãode cor do esmalte clinicamente perceptível, embora tenha sidoobservada diminuição da microdureza do esmalte com arealização dos tratamentos.

Effectiveness of nano-calcium phosphate paste on sensitivity during and after bleaching: a randomized clinical trial

The study aimed to evaluate the effectiveness of in-office bleaching and associated tooth sensitivity on application of nano-calcium phosphate paste as desensitizing agent. Bleaching was performed with 35% hydrogen peroxide gel in 40 patients who were randomly divided into placebo and nano-calcium phosphate paste groups. Bleaching efficacy (BE) was evaluated using a value-oriented Vita shade guide. Tooth sensitivity was recorded using a numeric rating scale (0–4) during bleaching and up to 48 h after each session. The primary outcome of absolute risk of tooth sensitivity was compared using the Fisher’s exact test (α = 0.05). The intensity of tooth sensitivity and the efficacy of in-office bleaching were also statistically evaluated. No significant differences in absolute risk and intensity of tooth sensitivity were detected between the groups (p = 1.0 and p = 0.53, respectively). BE was also found to be similar between the groups (p = 0.67). Although the use of a nano-calcium phosphate paste associated with fluoride and potassium nitrate did not influence the whitening outcome, but it also did not reduce bleaching-induced tooth sensitivity.

In vitro study on tooth enamel lesions related to whitening dentifrice.

Background: The tooth whitening substances for extrinsic use that are available in Brazil contain hydrogen peroxide or carbamide peroxide. Several studies have attributed the appearance of lesions in the enamel morphology, including hypersensitivity, to these substances. Such lesions justify fluoride therapy and application of infrared lasers, among other procedures. However, there is no consensus among researchers regarding the relevance of the severity of lesions detected on the tooth surface. Objectives: The present study was carried out with an aim of evaluating in vitro the effects of the hydrogen peroxide, carbamide peroxide and sodium bicarbonate contained in dentifrice formulations, on human tooth enamel. Materials and Methods: After darkening process in laboratory, human premolars were brushed using dentifrice containing the two whitening substances (Rembrandt - carbamide peroxide and Mentadent - hydrogen peroxide) and the abrasive product (Colgate - sodium bicarbonate). The degree of specimen staining before and after this procedure was determined using spectrophotometry. Scanning electron microscopy (SEM) was used to obtain images, which were analyzed to show the nature of the lesions that appeared on the enamel surface. Results: The effectiveness of the whitening caused by hydrogen peroxide and carbamide peroxide and the abrasion caused by bicarbonate were confirmed, given that the treated test pieces returned to their original coloration. Based on SEM, evaluation of the enamel surfaces subjected to the test products showed that different types of morphologic lesions of varying severity appeared. Conclusions: Whitening dentifrice containing hydrogen peroxide and carbamide peroxide produced lesions on the enamel surface such that the greatest sequelae were associated with exposure to hydrogen peroxide.

Blanqueamiento dentario: aplicaciones clínicas / Tooth bleaching: clinical applications

El presente artículo describe al blanqueamiento dental como una técnica de mínima intervención dentro de laodontología estética actual, la enumeración de los agentes blanqueadores y su mecanismo de acción, sus indicaciones y limitaciones así como los protocolos clínicos con el fin de lograr la armonía óptica de las piezas dentarias.