Combination of strontium chloride and photobiomodulation in the control of tooth sensitivity post-bleaching: A split-mouth randomized clinical trial.

OBJECTIVE: This split-mouth randomized controlled clinical trial assessed the effect of 10% strontium chloride in combination with photobiomodulation (PBM) for the control of tooth sensitivity (TS) post-bleaching. METHODS: The upper/lower, right and left quadrants of fifty volunteers were randomized and allocated to four groups (n = 25): PLACEBO-placebo gel + simulation of PBM; Placebo + PBM; STRONTIUM-10% strontium chloride + simulation of PBM; and PBM + STRONTIUM-10% strontium chloride + PBM. All groups received tooth bleaching treatment with 35% hydrogen peroxide. For the PBM treatment, the laser tip was positioned in the apical and cervical regions of the teeth bleached in the respective hemi-arch. The laser system was operated in continuous mode, using 1.7 J of energy. A dose of 60 J/cm2 was applied to each point for 16 seconds under 808 nm near-infrared light (100mW of power), with a point area of 0.028 cm2. TS was assessed during a 21-day follow-up, using the modified visual analogue scale. RESULTS: In the intragroup assessment, the Friedman test indicated that PBM + STRONTIUM promoted the greatest reduction in TS after the second week of treatment (p ≤ 0.05). The Wilcoxon-Mann-Whitney test indicated that the groups Placebo + PBM, STRONTIUM, and STRONTIUM + PBM did not differ statistically (p ≥ 0.05) in the first and third weeks of treatment The group PLACEBO exhibited the greatest TS in the first three days after each bleaching session. CONCLUSION: The combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, the combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, it did not differ from the individual use of Placebo + PBM or STRONTIUM groups assessed after 21 days of follow-up.

A yellowness index for use in dentistry.

OBJECTIVES: To develop an equation that predicts the perceptual yellowness of teeth. METHODS: A large set of new psychophysical yellowness data were generated from an experiment where 500 participants each ranked a set of 58 shade guide samples. Two existing equations (WIO and b*) and one new equation (YIO) were evaluated by comparing their values for the 58 shade guide tabs with the psychophysical data. Coefficient of determination (r2), '% wrong decisions', and STRESS were used as measures of performance. The YIO equation was optimized using these data to maximize the r2 value. A validation set of psychophysical data was prepared in an experiment where 40 participants each ranked 5 sets of 9 samples that were viewed on an emissive display. The candidate equations were evaluated using these data and the r2, %WD, and STRESS metrics. RESULTS: All three metrics YIO, WIO and b* were strongly correlated with perceptual yellowness. YIO and WIO both showed stronger correlation than b*. CONCLUSIONS: A new yellowness equation YIO has been developed to correlate with tooth yellowness. It is suggested that tooth yellowness and whiteness are highly related concepts.

Avaliação de diferentes protocolos no clareamento dentário / Evaluación de diferentes protocolos en el blanqueamiento dental / Evaluation of different protocols in dental bleaching

Introdução: A estética é a principal busca nos consultórios odontológicos e um dos tratamentos mais realizados é o clareamento dentário, a cada ano mais profissionais buscam a melhor técnica no que diz respeito a longevidade, efetividade, facilidade de passos clínicos e menor desconforto para o paciente Objetivo: Avaliar a influência da modificação do protocolo para aplicação de agentes clareadores utilizados em consultórios odontológicos, determinando a mudança de cor de diferentes agentes clareadores em dentes submetidos a diferentes protocolos. Material e métodos: Uma amostra de 20 dentes selecionados e codificados tiveram suas cores estabelecidas de acordo com a escala Vita Classica. Seccionados e divididos em quatro grupos entre protocolo convencional e modificado e uso dos agentes clareadores Whiteness HP e Whiteness HP Maxx. Resultados: A modificação do protocolo alcança resultados satisfatórios e sem diferença estatisticamente significativa quando comparado ao que é preconizado pelos fabricantes. Conclusões: Os resultados sugerem que a modificação pode representar uma ferramenta útil na prática clínica, uma vez que permite torna-lo mais eficaz, diminuir custos e quantidade de material utilizado(AU)

Introduction: Aesthetics is the main search in dental offices and one of the most accomplished treatments is dental bleaching, each year more professionals seek the best technique regarding longevity, effectiveness, ease of clinical steps and less discomfort for the patient Objective: To evaluate the influence of the modification of the protocol for the application of bleaching agents used in dental practices, determining the color change of different bleaching agents in teeth submitted to different protocols. Material and methods: A sample of 20 selected and coded teeth had their colors established according to the Vita Classica scale. Sectioned and divided into four groups between conventional and modified protocol and use of whitening agents Whiteness HP and Whiteness HP Maxx. Results: Modification of the protocol achieves satisfactory results and without statistically significant difference when compared to what is recommended by the manufacturers. Conclusions: The results suggest that the modification can represent a useful tool in clinical practice, since it allows to makes it more effective, to reduce costs and quantity of material used(AU)

Introducción: La estética es la principal búsqueda en los consultorios odontológicos y uno de los tratamientos más realizados es el blanqueamiento dental, cada año más profesionales buscan la mejor técnica en lo que se refiere a la longevidad, efectividad, facilidad de pasos clínicos y menor incomodidad para el paciente Objetivo: Evaluar la influencia de la modificación del protocolo para aplicación de agentes blanqueadores utilizados en consultorios odontológicos, determinando el cambio de color de diferentes agentes blanqueadores en dientes sometidos a diferentes protocolos. Material y métodos: Una muestra de 20 dientes seleccionados y codificados tuvo sus colores establecidos de acuerdo con la escala Vita Classica. Seccionados y divididos en cuatro grupos entre protocolo convencional y modificado y uso de los agentes blanqueadores Whiteness HP y Whiteness HP Maxx. Resultados: La modificación del protocolo alcanza resultados satisfactorios y sin diferencia estadísticamente significativa en comparación con lo que preconizan los fabricantes. Conclusiones: Los resultados sugieren que la modificación puede representar una herramienta útil en la práctica clínica, ya que permite hacer que sea más eficaz, disminuir los costos y la cantidad de material utilizado(AU)

Tooth whitening for the under-18-year-old patient.

Following changes in the EU regulations, it became legal for bleaching to be undertaken by dentists and their trained team. However, restrictions remained on bleaching for patients under the age of 18. A revised position statement by the General Dental Council (GDC) determined that bleaching could be undertaken on these patients if it was wholly for the purpose of treating or preventing disease. The purpose of this paper is to discuss the safety, efficacy, indications and techniques for under-18 bleaching.

Fechamento de diastema com resina composta direta: relato de caso clínico / Diastema closure with direct composite restorations: a case report

Com a evolução dos materiais restauradores adesivos diretos e das técnicas restauradoras minimamente invasivas, é possível realizar o fechamento de diastemas inter incisivos superiores de maneira efetiva e estética em uma única sessão. O presente trabalho consiste em um relato de caso clínico que aborda o clareamento dental e o fechamento de diastema entre os dentes 11 e 21 de um paciente jovem. Previamente ao procedimento restaurador foi realizado clareamento de consultório em todos os dentes com peróxido de hidrogênio 35%. Então, o planejamento restaurador foi auxiliado por modelos de estudo associado ao enceramento diagnóstico.A técnica restauradora de eleição foi a resina composta direta com o auxílio de uma matriz/guia de silicona para a confecção das faces palatinas das restaurações. Após o acabamento e polimento, obteve-se a reanatomização dos incisivos centrais com a eliminação do diastema. O tratamento realizado baseado no clareamento dental seguido por restaurações diretas de resina composta foi eficaz na solução estética do sorriso, atingindo a expectativa do paciente e dentro dos princípios de máxima preservação dos tecidos dentais.

After the evolution of restorative adhesive materials and minimal invasive restorations, it ispossible to close a maxilar interincisal diastema in an effective and aesthetical way, performingit in only one session. This clinical case report approaches a teeth bleaching and diastema closurewith composites between teeth 11 and 21, of a young male patient. The elective restorative technique was direct composite restoration with a silicon putty matrix to make the shape of thelingual surfaces of the restorations. Before the restoration procedure, it was performed “in office”bleaching technique, in addition to the case planning with the assistance of a wax-up. The tooth whitening therapy followed by direct composite restorations was effective, contributing to clinical success, esthetic and patient´s satisfaction.

Non-vital bleaching PART 1: an audit of practice in the Belfast and Cork restorative departments prior to the release of the 2012 European Cosmetic Directive PART 2: an audit on the perceived clinical impact of the 2012 European Cosmetic Directive in the Belfast and Cork restorative departments.

Intrinsic discolouration of teeth often requires bleaching to improve the aesthetics. There are three techniques available for non-vital bleaching: chairside; walking; and, inside/outside. Before the 2012 Cosmetic Directive was released, an audit of non-vital bleaching practice in the Belfast and Cork restorative departments was undertaken (Part 1). Results showed a variation in clinical procedures from the gold standard and therefore the latter was used to develop a clinical protocol and pro forma for use in the restorative departments. These were designed to be useful in the hospital and general dental practice settings, and should hopefully increase compliance with the gold standard and therefore improve both the consent process and record keeping. With the change in the European Cosmetic Directive Guidelines on October 31, 2012, dentists were confined to using a maximum of 6% hydrogen peroxide in tooth bleaching products provided the first application was by a dentist or under their direct supervision. A high proportion of audit responses in Part 1 involved concentrations of hydrogen peroxide, in both the walking and chairside techniques, that no longer complied with the new Directive. This suggested that the new Cosmetic Directive could significantly impact the practice of non-vital bleaching in the Belfast and Cork restorative departments. This in turn prompted an evaluation on the perceived clinical impact of the European Cosmetic Directive since its release in 2012 (Part 2). Surprisingly, clinicians found similar clinical outcomes following the restriction in the concentration of bleach, although 50% felt that more treatment visits were required to achieve an acceptable result. Moreover, the results of the audit revealed that clinicians were most concerned that the introduction of a ban on treating patients under 18 years of age might exacerbate psychological issues in this vulnerable age group if discoloured teeth were left untreated.

[Research on the designing method of a special shade guide for tooth whitening].

OBJECTIVE: To investigate a method of designing an accurate and scientific shade guide, especially used for judging the effect of tooth whitening, by analyzing the colorimetric values of discolored teeth statistically. METHODS: One hundred thirty-six pictures of patients who had been receiving the Beyond cold light whitening treatment from February 2009 to July 2014 were analyzed, including 25 tetracycline teeth, 61 mottled-enamel teeth, and 50 yellow teeth. The colorimetric values of discolored teeth were measured. The L* values of shade tabs were calculated by hierarchical clustering of those of discolored teeth. The a* and b* values of shade tabs were the mean of those observed for discolored teeth. Accordingly, different shade guides were designed for each type of discolored teeth, and the effects were evaluated. RESULTS: A statistically significant difference in colorimetric values was found among the three types of discolored teeth. Compared with the Vitapan Classical shade guide, the shade guides designed through the present method were more scientific and accurate in judging the effect of tooth whitening. Moreover, the arrangement of shade tabs was more logical, and the color difference between shade tabs and discolored teeth was smaller. CONCLUSION: The proposed designing method is theoretically feasible, although its clinical effect has yet to be proven.

Tooth whitening: what we now know.

UNLABELLED: Current research about tooth whitening shows that it is safe and effective when manufacturer's protocol is followed, yet there are risks of which the profession and users should be aware. This update provides a summary of current research and assessment of the safety and efficacy of tooth whitening regimens. BACKGROUND: Tooth whitening has become one of the most frequently requested dental procedures by the public. The public has come to demand whiter, more perfect smiles and in response many choices for tooth whitening have been made available. These include home-based products such as toothpastes, gels, and films, as well as in-office based systems where products containing highly concentrated bleaching agents are applied under professional supervision. The profession and public have been aware of certain risks related to tooth whitening such as increased tooth sensitivity and gingival irritation. New research has shown that there are other risks such as tooth surface roughening and softening, increased potential for demineralization, degradation of dental restorations, and unacceptable color change of dental restorations. The new research is also focused on optimizing whitening procedures to reduce tooth sensitivity and to increase the persistence of the whitening. METHODS: Current reports in the literature are reviewed that are related to the use of peroxide based whitening methods. These reports include in vitro studies for method optimization and mechanism as well as clinical studies on effects of various whitening regimens. CONCLUSIONS: When manufacturer's instructions are followed, hydrogen peroxide and carbamide peroxide based tooth whitening is safe and effective. Patients should be informed of the risks associated with tooth whitening and instructed on identification of adverse occurrences so that they may seek professional help as needed.

Concentrations of and application protocols for hydrogen peroxide bleaching gels: effects on pulp cell viability and whitening efficacy.

OBJECTIVES: To assess the whitening effectiveness and the trans-enamel/trans-dentinal toxicity of experimental tooth-bleaching protocols on pulp cells. METHODS: Enamel/dentine discs individually adapted to trans-well devices were placed on cultured odontoblast-like cells (MDPC-23) or human dental pulp cells (HDPCs). The following groups were formed: G1 - no treatment (control); G2 to G4 - 35% H2O2, 3 × 15, 1 × 15, and 1 × 5 min, respectively; and G5 to G7 - 17.5% H2O2, 3 × 15, 1 × 15, and 1 × 5 min, respectively. Cell viability and morphology were evaluated immediately after bleaching (T1) and 72 h thereafter (T2). Oxidative stress and cell membrane damage were also assessed (T1). The amount of H2O2 in culture medium was quantified (Mann-Whitney; α=5%) and colour change (ΔE) of enamel was analysed after 3 sessions (Tukey's test; α=5%). RESULTS: Cell viability reduction, H2O2 diffusion, cell morphology alteration, oxidative stress, and cell membrane damage occurred in a concentration-/time-dependent fashion. The cell viability reduction was significant in all groups for HDPCs and only for G2, G3, and G5 in MDPC-23 cells compared with G1. Significant cell viability and morphology recovery were observed in all groups at T2, except for G2 in HDPCs. The highest ΔE value was found in G2. However, all groups presented significant ΔE increases compared with G1. CONCLUSION: Shortening the contact time of a 35%-H2O2 gel for 5 min, or reducing its concentration to 17.5% and applying it for 45, 15, or 5 min produce gradual tooth colour change associated with reduced trans-enamel and trans-dentinal cytotoxicity to pulp cells. CLINICAL SIGNIFICANCE: The experimental protocols tested in the present study provided significant tooth-bleaching improvement associated with decreased toxicity to pulp cells, which may be an interesting alternative to be tested in clinical situations intended to reduce tooth sensitivity and pulp damage.

Evaluation of the effectiveness of an in-office bleaching system and the effect of potassium nitrate as a desensitizing agent.

The aims of the study were to evaluate by spectrophotometer the in vivo colour changes resulting from the application of an in-office tooth bleaching system containing 28% H2O2 by light-emitting diode (LED) activation and to determine whether the application of 5% potassium nitrate 30 min before bleaching decreased tooth sensitivity. Thirty-two individuals were assigned randomly to two groups (n = 16). Group A received 5% potassium nitrate as a desensitizing agent 30 min before bleaching with 28% hydrogen peroxide activated by LED. Group B received glycerin as a placebo and the same bleaching protocol was applied. The colour of the right central incisor of each patient was measured visually and by spectrophotometer before bleaching, immediately thereafter, 15 days and 3 months later. Differences in L* a* b* values were tested with a repeated measures analysis of variance (ANOVA). Differences in ΔΕ values were tested with ANOVA statistical analysis at a 0.05 level of significance. Significant (p < 0.05) differences were detected in L*, as well as in b* values, between initial (I) and post bleaching (PB) and between initial (I) and 3 months post-op. In contrast, there was no significant difference between PB and 3 months post-op. The a* values showed no statistically significant differences among the different time points. Tooth sensitivity decreased significantly when potassium nitrate was applied. In-office bleaching system gave quantitatively stable results over a 3-month period. Tooth sensitivity was reduced significantly, when a desensitizing agent was applied 30 min before treatment, but the efficacy of bleaching decreased.

Development of polarization dental imaging modality and evaluation of its clinical feasibility.

OBJECTIVES: In the evaluation of tooth color, the specular reflection caused by roughness or saliva on the tooth surface may cause artefacts in image analysis. In this study, a polarization dental imaging modality (PDIM) was developed to obtain cross-polarized images and, therefore, to address the problem of specular reflection. Its clinical validity was evaluated by performing 3 studies of shade tab selection for implant, plaque distribution detection, and evaluation of tooth whitening. METHODS: In vivo human tooth and shade guide color images were obtained, and the minimum color difference between them was calculated for the best color matching shade tab selection. A dental plaque disclosing agent was used to differentiate plaque regions on teeth, and plaque distribution was detected by applying the K-means algorithm. In vivo human teeth were treated with a commercial tooth whitening gel, and tooth whitening was quantitatively evaluated using the PDIM images. RESULTS: The PDIM produced repeatable glare-free tooth color images by effectively removing the specular reflection from the tooth surface. The cross-polarized tooth images were successfully utilized for shade guide selection, plaque detection, and tooth whitening by minimizing artefacts in the quantitative image analysis. The PDIM could simultaneously provide both qualitative and quantitative assessment of the tooth condition in clinical diagnosis. CONCLUSIONS: The clinical feasibility of the PDIM was successfully verified in 3 clinical studies by showing its clinical efficacy as a new imaging modality.

A novel method for testing the veridicality of dental colour assessments.

The Commission Internationale de l'Eclairage (CIE) L*a*b* three-dimensional coordinates suggest strong correlations between the data of a* (red-green axis) and b* (blue-yellow axis), as both are located on the same plane in the model and should therefore show a strong dependency. In order to assess the veridicality of colour determinations, the null hypothesis of no significant changes in CIE-a*/b* coherences of dental colours following a colour or lightness change induced by external dental bleaching was tested. Values from 231 extracted anterior teeth were assessed using the digital photographic CIELAB recalculation method. Teeth were then assigned to three groups (n = 77) with contrasting baseline CIE-L* values. Group A served as the control with no alteration in dental colour. The specimens in the two other groups were altered in colour or lightness employing treatment with either 15 per cent carbamide peroxide (group B) or 38 per cent hydrogen peroxide (group C). Pearson's pairwise correlation coefficient of CIE-L*; a*, CIE-L*; b*, and CIE-a*; b* were calculated for assessments at baseline (T0) and after 2 (T1), 4 (T2), 12 (T3), and 24 (T4) weeks. The correlations of a* and b* from T0 to T4, in relation to group A, were stable, with coefficients of 0.78→0.65→0.65→0.69→0.67. Bleaching-induced colour and lightness changes did not have a significant influence on the a*/b* coherences assessed. A distinctly weaker and inverse relationship was observed between L* and a* values and between L* and b* values in the groups, with correlation coefficients ranging from -0.54 to -0.12. Colour coherences detected at specific points in time were in agreement with theoretical CIE colour coherences. In order to compare the methodology of different colour analyses, the analysis of correlations between CIE-a* and -b* values is advocated as an additional routine test in future CIELAB studies.

Safety controversies in tooth bleaching.

Tooth bleaching using peroxide-based materials is an effective procedure in dentistry. Studies provide evidence on the safety of bleaching by dental professionals. However, concerns and controversy remain regarding the safety of bleaching systems that do not involve dental professionals, especially those available at mall kiosks, salons, spas, and cruise ships. Bleaching causes tooth sensitivity and/or gingival irritation in a significant portion of patients. Bleaching requires proper examination, diagnosis, and treatment plan, which can be performed appropriately only by dental professionals; therefore, involvement of dental professionals in bleaching is necessary to maximize the efficacy and minimize potential risks.

Over-the-counter whitening agents: a concise review.

Tooth discoloration is commonly found in the dental clinic and tooth bleaching has been considered the preferred esthetic alternative, being more conservative, safe and with predictable results. Supervised home-use of 10% Carbamide Peroxide (CP) bleaching with custom-trays is the most common bleaching procedure dispensed by dentists to their patients. The good results obtained with this technique stimulated the flourishing of new products and techniques. Over-the-counter (OTC) bleaching products appeared as a low-cost alternative to bleach discolored teeth without dentist supervision. Different OTC products are available in supermarkets, drug stores or on the Internet, including rinses, paint-on brushes, toothpastes, chewing guns, dental floss, and whitening strips. There is lack of clinical evidence regarding the safety and effectiveness of these products, being most of the studies supported by the manufacturers'. Basically, toothpastes, chewing gums, and dental floss are removal agents of superficial stains. Rinses and paint-on brushes with low levels of hydrogen peroxide have some whitening effect, but without clinical relevance. Strips present similar esthetic results and side-effects, compared to bleaching with 10% CP using trays; however, the studies have financial support from the manufacturers and were based on short term evaluations. Legislation varies widely in different countries regarding OTC dental bleaching. Concerns have appeared due to the potential abusive use of these self-medication agents, especially in young patients, with potential harmful results. Dentists should be acquainted with this kind of products to be able to inform their patients. In conclusion, there is a need for independent clinical trials to provide sufficient evidence regarding the use of OTC bleaching products.