Using artificial intelligence to predict the final color of leucite-reinforced ceramic restorations.

OBJECTIVES: The aim of this study was to evaluate the accuracy of machine learning regression models in predicting the final color of leucite-reinforced glass CAD/CAM ceramic veneer restorations based on substrate shade, ceramic shade, thickness and translucency. METHODS: Leucite-reinforced glass ceramics in four different shades were sectioned in thicknesses of 0.3, 0.5, 0.7, and 1.2 mm. The CIELab coordinates of each specimen were obtained over four different backgrounds (black, white, A1, and A3) interposed with an experimental translucent resin cement using a calibrated spectrophotometer. The color change (CIEDE2000) values, as well as all the CIELab values for each one of the experimental groups, were submitted to 28 different regression models. Each regression model was adjusted according to the weights of each dependent variable to achieve the best-fitting model. RESULTS: Different substrates, ceramic shades, and thicknesses influenced the L, a, and b of the final restoration. Of all variables, the substrate influenced the final ceramic shade most, followed by the ceramic thickness and the L, a, and b of the ceramic. The decision tree regression model had the lowest mean absolute error and highest accuracy to predict the shade of the ceramic restoration according to the substrate shade, ceramic shade and thickness. CLINICAL SIGNIFICANCE: The machine learning regression model developed in the study can help clinicians predict the final color of the ceramic veneers made with leucite-reinforced glass CAD/CAM ceramic HT and LT when cemented with translucent cements, based on the color of the substrate and ceramic thicknesses.

New Single-bottle Ceramic Primer: 6-month Case Report and Laboratory Performance.

INTRODUCTION: This article presents a 6-month case report and an in vitro evaluation of the performance of the new self-etching glass-ceramic monobond etch and prime (MEP) when applied in a lithium disilicate (LD). The MEP contains in the same bottle, along with acid conditioner and silanes. This simplifies the bonding procedures by reducing not only the number of steps, but also the working time. A 42-year-old female patient sought for esthetic treatment, and the main complaint was the darkened appearance of the upper lateral incisor. The esthetic treatment includes dental bleaching and gingivectomy, all-ceramic zirco-nia crowns, and all-ceramic crown and laminate veneer LD. After 6 months of esthetic treatment, marginal staining, gap, or chip fracturing damaging margins after sharp explorer in the margins was not observed. Furthermore, the inferior etching pattern of MEP was compared with traditional hydrofluoric acid (HF) conditioning. The microshear bond strength to the intaglio surface of LD was statistically similar when HF was compared with MEP. This new self-etching glass-ceramic showed good in vitro and 6 months clinical results in this case report. Future long-term clinical studies with more clinical case need to be done to confirm the performance of the use of this new conditioner. CLINICAL SIGNIFICANCE: The use of a new self-etching glass-ceramic showed a good in vitro and 6 months clinical results. This new product can be an easy, simple, and alternative approach for esthetics bonding procedure.

Randomized clinical trial of four adhesion strategies in cervical lesions: 12-month results.

The aim of this study was to evaluate the 6- and 12-month clinical performance of four adhesion strategies from the same manufacturer (Kerr) in non-carious cervical lesions (NCCLs) using two evaluation criteria. Thirty-five patients, with at least four NCCLs each, participated in this study. After samplesize calculation, 180 restorations were assigned to one of the following groups: OFL (Optibond FL), OSP (Optibond Solo Plus), XTR (Optibond XTR), and AIO (Optibond All-In-One). The composite resin Filtek Supreme Ultra (3M ESPE) was placed incrementally. The restorations were evaluated at baseline, after 6 months, and after 12 months, using both the FDI and the USPHS-modified criteria. Statistical analyses were performed with Friedman repeated measures, ANOVA by rank, and the McNemar test for significance in each pair (α=0.05). Six restorations (2 for OFL, 1 for OSP, 2 for XTR, and 1 for AIO) were lost at 12 months (P>0.05 for both evaluation criteria). Marginal staining was observed in seven restorations using the FDI criteria (P>0.05) and three restorations using the USPHSmodified criteria (P>0.05). Eight restorations (2 for OSP, 3 for XTR, and 3 for AIO) were classified as Bravo for marginal adaptation using the USPHSmodified criteria (P>0.05). However, 62 restorations (14 for OFL, 12 for OSP, 15 for XTR, and 21 for AIO) were classified as Bravo using the FDI criteria (P>0.05). The four adhesion strategies showed similar clinical retention at 6 and 12 months. The FDI evaluation criteria tend to be more sensitive than the USPHS-modified criteria.

Simplificando la adhesión con un sistema adhesivo universal: reporte de casos / Clinical application of a new universal adhesive system: case reports

Los sistemas adhesivos tienden a ser cada vez más simplificados y versátiles. Hasta el presente, el clínico todavía debe elegir entre adhesivos autoacondicionantes o convencionales. Objetivo: mostrar la aplicación clínica de un nuevo sistema adhesivo considerado universal, debido a que puede ser usado como adhesivo autoacondicionante o como uno convencional. Caso clínico: fueron realizadas restauraciones cervicales en lesiones no cariosas con varias posibilidades de utilización de un nuevo adhesivo (Scotchbond(TM) Universal, 3M Espe), aplicando el ácido fosfórico en toda la cavidad y dejando la dentina seca o húmeda, o aplicando el ácido fosfórico solamente en el esmalte, o aplicando sólo el adhesivo sin grabado previo con ácido fosfórico. Después de restaurar con resina compuesta, todos los casos fueron evaluados clínicamente en el inicio del tratamiento y a los 6 meses. Conclusión: los resultados demostraron un excelente desempeño clínico de este nuevo sistema adhesivo, utilizado con cualquiera de las distintas técnicas clínicas propuestas. No obstante, deben realizarse estudios de larga duración en un mayor número de casos clínicos, a fin de comprobar los resultados aquí presentados

Simplificando la adhesión con un sistema adhesivo universal: reporte de casos / Clinical application of a new universal adhesive system: case reports

Los sistemas adhesivos tienden a ser cada vez más simplificados y versátiles. Hasta el presente, el clínico todavía debe elegir entre adhesivos autoacondicionantes o convencionales. Objetivo: mostrar la aplicación clínica de un nuevo sistema adhesivo considerado universal, debido a que puede ser usado como adhesivo autoacondicionante o como uno convencional. Caso clínico: fueron realizadas restauraciones cervicales en lesiones no cariosas con varias posibilidades de utilización de un nuevo adhesivo (Scotchbond(TM) Universal, 3M Espe), aplicando el ácido fosfórico en toda la cavidad y dejando la dentina seca o húmeda, o aplicando el ácido fosfórico solamente en el esmalte, o aplicando sólo el adhesivo sin grabado previo con ácido fosfórico. Después de restaurar con resina compuesta, todos los casos fueron evaluados clínicamente en el inicio del tratamiento y a los 6 meses. Conclusión: los resultados demostraron un excelente desempeño clínico de este nuevo sistema adhesivo, utilizado con cualquiera de las distintas técnicas clínicas propuestas. No obstante, deben realizarse estudios de larga duración en un mayor número de casos clínicos, a fin de comprobar los resultados aquí presentados (AU)

A new universal simplified adhesive: 6-month clinical evaluation.

STATEMENT OF THE PROBLEM: Multimode adhesives, which can be used as etch-and-rinse or as self-etch adhesives, have been recently introduced without clinical data to back their use. PURPOSE OF THE STUDY: To evaluate the 6-month clinical performance of Scotchbond Universal Adhesive (SU; 3M ESPE, St. Paul, MN, USA) in noncarious cervical lesions (NCCLs) using two evaluation criteria. METHODS/MATERIALS: Thirty-nine patients participated in this study. Two hundred restorations were assigned to four groups: SU-TEm: etch-and-rinse + moist dentin; SU-TEd: etch-and-rinse + dry dentin; SU-SEet: selective enamel etching; and SU-SE: self-etch. The composite resin Filtek Supreme Ultra (3M ESPE) was placed incrementally. The restorations were evaluated at baseline and after 6 months using both the World Dental Federation (FDI) and the United States Public Health Service (USPHS) criteria. Statistical analyses were performed with Friedman repeated measures analysis of variance by rank and McNemar test for significance in each pair (α = 0.05). RESULTS: Only four restorations (SU-SE: 3 and SU-TEm: 1) were lost after 6 months (p > 0.05 for either criteria). Marginal discoloration occurred in one restoration in the SU-SE group (p > 0.05 for either criteria). Only 2/200 restorations were scored as bravo for marginal adaptation using the USPHS criteria (one for SU-SE and one for SU-SEet, p > 0.05). However, when using the FDI criteria, the percentage of bravo scores for marginal adaptation at 6 months were 32%, 36%, 42%, and 46% for groups SU-TEm, SU-TEd, SU-SEet, and SU-SE, respectively (p > 0.05). CONCLUSIONS: The clinical behavior of the multimode adhesive does not depend on the bonding strategy at 6 months. The FDI evaluation criteria are more sensitive than the USPHS criteria. CLINICAL SIGNIFICANCE: At 6 months, the clinical behavior of the new multimode adhesive Scotchbond Universal was found to be reliable when used in noncarious cervical lesions and may not depend on the bonding strategy employed.

Apliacação de um novo sistema adesivo universal: relato de caso / Aplication of a new universal adhesive system: case report

Apesar de se tentar com que os adesivos atuais sejam cada vez mais simplificados e versáteis, até o momento o clinico deve optar por adesivos autocondicionantes ou convencionais. O presente relato de caso visa apresentar a aplicação clínica de um novo sistema adesivo considerado universal, pois pode ser usado na técnica autocondicionante ou convencional. Foram realizadas restaurações de lesões cervicais não cariosas com as várias possibilidades de aplicação do adesivo Single Bond Universal, ou seja, aplicando o ácido fosfórico em toda a cavidade e deixando a dentina seca ou úmida; aplicando o ácido fosfórico apenas no esmalte, ou aplicando apenas o adesivo sem a utilização do ácido fosfórico. Após a realização das restaurações com resina composta, estas foram avaliadas inicialmente e após seis meses. Os resultados demonstraram um excelente desempenho clínico quando este novo sistema adesivo foi utilizado em quaisquer das estratégias propostas. Estudos de longa duração e um maior número de casos clínicos devem ser realizados para comprovar os resultados aqui apresentados

In spite of trying to make the current adhesive systems more simplified and versatile, until the moment the clinician should choose self-etch or etch-and-rinse adhesives. This case report aims to present the clinical application of a new adhesive system considered as universal, as it can be used under the self-etch or etch-and-rinse protocols. Caries-free cervical lesions were restored with the different application modes of the adhesive Single Bond Universal, that is, etching the entire cavity leaving dry or moist dentin, enamel etching only or applying the adhesive without etching. After finishing the restoration with resin composite, there were evaluated at baseline and after 6 months. The results demonstrated an excellent clinical behavior when this new adhesive system was used under any protocol proposed. Long term studies and more clinical reports are needed to prove the results here presented

Associação de técnicas para diminuição da sensibilidade advinda do clareamento caseiro / Association of techniques for decreasing the sensibility coming from dental bleaching at home

A sensibilidade dentária associada ao clareamento dentário é a principal causa de desistência dos pacientes em relação à procura desse procedimento ou suspensão da continuidade do tratamento clareador. Para isso, tanto modificações químicas nos agentes clareadores, quanto estratégias clínicas têm sido propostas para eliminar e/ou controlar esse sintoma indesejado sem prejudicar o resultado estético final almejado. O presente trabalho relata um caso clínico onde várias estratégias foram utilizadas para eliminar a sensibilidade causada pelo clareamento caseiro com peróxido de carbamida 16 por cento. Ao final, o paciente ficou muito satisfeito com o resultado estético e não houve relato de ocorrência de sensibilidade durante o prOcedimento clareador

The main cause of patients withdrawal in relation to the demand for this procedure or suspension of bleaching is the dental sensitivity. For this, both modifcations in bleaching agents as clinical strategies have been proposed to eliminate and/or control this unwanted symptoms without affecting the fnal esthetic result. The present case report shows the association of several strategies to decrease the dental bleaching sensitivity caused by 16% peroxide carbamide gel for at-home bleaching. The results showed that the patient was very satisfed with the bleaching result and there was no record of sensitivity during the bleaching procedure.

Long-term efficacy of in-office and at-home bleaching: a 2-year double-blind randomized clinical trial.

PURPOSE: This parallel, double-blind randomized clinical trial evaluated the 2-year bleaching efficacy and sensitivity produced by at-home (AH) and in-office (IO) bleaching therapies. METHODS: 60 participants with tooth color darker than C2, without restorations in the anterior dentition and older than 18 years old, were randomly allocated into two groups to receive either IO with 35% hydrogen peroxide or AH with 16% carbamide peroxide. Color was recorded at baseline (BA); 1-week (1W); end of the treatment (ET); and 2 years (2Y) after bleaching, using the Vita Classical shade guide. The perception of TS was recorded on a 0-4 scale during and 2Y after bleaching. The variation in shade guide units (deltaSGU) from BA vs. 1W was compared to deltaSGU from BA vs. 2Y using paired t-test. The percentage of subjects who reported TS was evaluated by Fisher's exact test. The intensity of TS was evaluated by a Mann-Whitney test (alpha=0.05). RESULTS: Both bleaching techniques demonstrated equivalent and significant tooth color shade lightening. No significant color rebound occurred after 2Y for both techniques (P= 0.77 and 0.87, for AH and IO respectively). The absolute risk of TS was similar for IO and AH (P= 0.12), however the intensity of TS was significantly higher for IO (P= 0.001). No subjects reported sensitivity after 2Y.

Previsibilidade com cerâmicas em dentes anteriores: IPS e. max press e e. max ceram / Predictability with ceramics in anterior teeth: IPS e. max press and e. max ceram

Desde o início da utilização das cerâmicas na Odontologia, essas têm recebido grande destaque porque dificilmente algum outro material consegue reproduzir com tanta naturalidade a estrutura dentária. Após o surgimento dos procedimentos adesivos e das cerâmicas metal-free, foi possivel o restabelecimento estético de dentes anteriores com segurança e qualidade estética. O paciente apresentado no presente relato de caso, do sexo masculino, com 28 anos de idade, apresentou-se com os elementos 11 e 21 tratados endodonticamente, escurecidos, com presença de restaurações em resina composta e deficiência no contorno gengival. Para o tratamento, recomendou-se utilização de pinos em fibra de vidro e coroas metal-free. Para melhorar o contorno e nível gengival, foi realizada cirurgia plástica gengival nos elementos 11 e 21. A cerâmica de escolha para a confecção das coroas foi a reforçada por dissilicato de lítio IPS e. max Press e cerâmica de cobertura IPS e. max Ceram com cristais de nanofluorapatita. Após a confecção dos preparos, foi realizada a moldagem e confeccionadas as estruturas cerâmicas, estratificadas com a cerâmica de cobertura. Em seguida, realizou-se a prova das peças protéticas, ajuste com pontas abrasivas para cerâmica e cimentação com cimento resinoso químico. Com as coroas cimentadas, observou-se uma perfeita adaptação marginal e naturalidade com as estruturas dentárias naturais, garantindo o biomimetismo proposto pelas restaurações cerâmicas.

Clinical effects of at-home bleaching along with desensitizing agent application.

PURPOSE: To evaluate whether the use of a desensitizing agent before at-home vital bleaching decreased this sensitivity. METHODS: After informed consent, 60 subjects, 18-31 years of age, participated in the study and were divided into desensitizer and placebo groups. Before bleaching treatment with 16% carbamide peroxide (CP), a placebo or desensitizer gel (DG; 5% potassium nitrate and 2% sodium fluoride) was applied in the tray and used by patients for 10 minutes. Color was evaluated at the baseline, second and fourth week following the initial delivery of bleaching trays. Color change was measured using the Vita Classic Shade Guide arranged by value. The subjects recorded their perception of tooth sensitivity on a 0-4 scale. The bleaching treatment at each week recall was evaluated by repeated measures ANOVA. The percentage of patients with tooth sensitivity was evaluated by Chi-square test. The tooth intensity ratio (% of days with tooth sensitivity) as well as the tooth sensitivity intensity between groups were analyzed using chi-square and the Mann-Whitney tests, respectively (alpha = 0.05). RESULTS: The use of DG did not affect the bleaching efficacy of the CP (P > 0.05). The prevalence and intensity of tooth sensitivity was similar for both groups (P > 0.05). However, participants from the placebo group had sensitivity in 33.6% of the bleaching days, which was significantly higher than the DG experimental group (20.1%) (P < 0.05).

Prevenção da sensibilidade causada pelo clareamento caseiro: relato de caso / Preventive effect af a desensitizing gel befare at -hame bleaching: case repart

o clareamento dental tem se tornado um tratamento de rotina na odontologia atual, mas, apesar dos ótimos resultados obtidos com as técnicas clareadoras, a ocorrência da sensibilidade dental é comum e relatada por grande parte dos pacientes. Diversos estudos indicam que, a utilização de dessensibilizantes diretamente sobre os dentes, ou adicionados nas formulações dos clareadores, pode reduzir a sensibilidade associada ao clareamento. Considerando que esta sensibilidade é um efeito adverso comum e imprevisivel, devemos adotar uma postura preventiva, pois, para alguns pacientes essa sensibilidade pode ser severa o suficiente para causar a interrupção do tratamento, e ainda, causar um efeito negativo sobre a indicação do clareamento para outros pacientes. O objetivo deste relato de caso é demonstrar a utilização dos produtos dessensibilizantes, visando à prevenção da sensibilidade no clareamento caseiro. Antes de cada aplicação do gel clareador, um gel dessensibilizante foi aplicado nas moldeiras e usado durante 10 minutos. Observou-se que o uso do gel dessensibilizante não afetou a eficácia do tratamento clareador, e o paciente não apresentou qualquer sintomatologia dolorosa durante o tratamento.

The dental bleaching has became a routine treatment in current dentistry, but, in spi- te of great results with the bleaching techniques, the tooth sensitivity is a common side effect reported by most of the patients. Many studies indicate that the use of desensitizing agents directly on the teeth surfaces or its addition to bleaching formulations can redu- ce the sensibility associated to the bleaching. Considering the sensitivity a common and unpredictable problem, we should adopt the preventive posture, as for some patients this sensitivity can be severe enough to lead to treatment interruption, and still cause a nega- tive effect in the indication of this treatment to other patients. The purpose of this clinical case report is to demonstrate the use of a desensitizing agent to prevent the sensitivity for at-home bleaching. Before each application with 16% carbamide peroxide, a desensitizing gel was applied in the tray and worn by patients for 10 minutes. It was observed that the use of desensitizing gel did not affect the effectiveness of the bleaching treatment, and the patient did not have any painful symptoms during dental bleaching. Clinical significance: The use of a desensitizing gel along with at-home bleaching can reduce tooth sensitivity, the most common side effect associated with this procedure.

Uso de un agente desensibilizante antes del clareamiento en consultorio: reporte de caso / Use of a desensitizing agent before dental bleaching: case report

La sensibilidad dental se presenta como un problema común e impredecible al realizar tratamientos clareadores, ya sea con técnicas caseras o de consultorio; generalmente esta sensibilidad es moderada y se produce durante o después del tratamiento, pudiendo llegar en algunos casos a interrumpir el tratamiento. Varios estudios sugieren la aplicación de productos desensibilizantes directamente en los dientes, otros adicionan estos productos a las pastas dentales y productos clareadores para reducir el malestar del paciente. En general, los dentistas tratan la sensibilidad cuando ya ocurrió, pero en este momento la cooperación del paciente puede estar ya afectada y como consecuencia llegar a un tratamiento insatisfactorio. El objetivo de este reporte de caso es demostrar un nuevo protocolo de clareamiento usando un agente desensibilizante antes del tratamiento para prevenir la sensibilidad. En este caso, fue colocado un agente desensibilizante en las caras vestibulares de todos los dientes anteriores por 10 minutos antes del tratamiento clareador en consultorio. El mismo procedimiento se repitió después de una semana. Se observó que el uso de un gel desensibilizante a base de nitrato de potasio y flúor antes del clareamiento en consultorio no afecta la eficacia clareadora del peróxido de hidrógeno y el paciente no indicó sensibilidad después del tratamiento.

Tooth sensitivity is a common and unpredictable problem when bleaching treatments are performed in-office and home techniques. This sensitivity is usually mild in nature and resolves either during or upon completion of treatment; however in some cases they are responsible for treatment with drawal. Several studies suggest the use of desensitizing products applied directly on the teeth, others added in the formulation of toothpastes and bleaching products to reduce the discomfort for the patient. In general, dentists treat sensitivity after its occurrence, but at this time the cooperation of the patient may already be affected, leading to an unsatisfactory outcome. The objective of this case report is to demonstrate a new technique of using desensitizing products to prevent the sensitivity. In this case, before the in-office bleaching technique, a desensitizing gel was applied on the buccal surfaces of the anterior teeth for 10 min. The same procedure was repeated after one week. It was observed that the use of the desensitizing gel (5% nitrate potassium/2% NaF) before the in-office bleaching does not affect the bleaching efficacy with hydrogen peroxide and the patient did not indicate sensitivity after treatment.

A clorexidina como alternativa para maximizar a longevidade de união de restaurações adesivas / Chlorhexidine as an alternative to maximize bonding longevity of adhesive restorations

Materiais restauradores e sistemas adesivos são amplamente estudados por pesquisadores do mundo todo, entretanto, parte desses estudos não é conhecida pelos cirurgiões-dentistas. Que deixam de se beneficiar dos avanços dessa área. Além disso, alterações nas técnicas tradicionais não são facilmente incorporadas à rotina desses profissionais. Este artigo apresenta um relato de caso em que se utilizou a clorexidina, de maneira simples, como parte do procedimento adesivo, objetivando ampliar a longevidade da restauração em resina composta. Uma revisão da literatura sobre o assunto é realizada, a fim de justificar a utilização da técnica e destacar os benefícios da clorexidina, mostrados por várias pesquisas, com o propósito de aumentar a longevidade da interface adesiva

Although restorative materials and adhesive systems have been widely studied by worldwide researchers, few private practitioners are aware of their findings and therefore they do not take advances in this field. In addition, changes in routinely used restorative protocols are not easily to daily’s practice. This article reports a clinical case where chlorhexidine was used as a part of the bonding protocol in order to improve the longevity of the adhesive interface of a composite resin restoration. A review of the literature was also performed in order to provide and evidence-based background for this novel bonding protocol and to highlight the ability of the chlorhexidine in improving the longevity of the adhesive interface

Prevenção da sensibilidade causada pelo clareamento de consultório: relato de caso / Prevention of sensitivity caused by in-office tooth bleaching: case report

A sensibilidade dentária é um problema comum e imprevisível quando se realizam tratamentos clareadores, tanto na técnica de consultório como na técnica caseira, sendo que muitas vezes a mesma impossibilita a finalização do tratamento. Diversos estudos sugerem a utilização de dessensibilizantes - aplicados diretamente sobre os dentes, como também adicionados na formulação de dentifrícios e dos próprios clareadores - como forma de diminuir esse desconforto para o paciente. Em geral, os cirurgiões-dentistas tratam a sensibilidade após o seu aparecimento. Porém, nesse momento, a cooperação do paciente pode já estar comprometida, levando a um resultado final insatisfatório. O objetivo deste relato de caso é demonstrar uma nova técnica de utilização dos produtos dessensibilizantes, visando à prevenção da sensibilidade: antes do clareamento na técnica de consultório, um gel dessensibilizante foi aplicado nas faces vestibulares dos dentes durante 10 minutos. O mesmo procedimento foi repetido após uma semana. Observou-se que o uso do gel dessensibilizante não afetou a eficácia do clareamento com peróxido de hidrogênio, e o paciente não apresentou qualquer sintomatologia dolorosa pós-clareamento dentário.

Assessing the effect of a desensitizing agent used before in-office tooth bleaching.

BACKGROUND: Tooth sensitivity has been reported with in-office tooth bleaching. The authors conducted a study to evaluate whether the use of a desensitizing agent before in-office bleaching decreased this sensitivity. METHODS: Before in-office bleaching with a 35 percent hydrogen peroxide gel (three applications of 15 minutes each), clinicians applied a placebo gel on the buccal surfaces of all teeth in 15 participants in the control group, which was left undisturbed for 10 minutes. The clinicians applied a desensitizing agent to the teeth of 15 participants in the experimental group in the same manner as that described for the control (placebo) group. They repeated this protocol one week later. Patients recorded their tooth sensitivity on a 0-to-4 scale. The authors used t test (alpha = .05) to compare the tooth color changes and the intensity of tooth sensitivity between groups at baseline and immediately after the first and second appointments. The authors used Fisher exact test and t test (alpha = .05), respectively, to analyze the percentage of patients with tooth sensitivity and its intensity. RESULTS: The use of a desensitizing gel did not affect the bleaching efficacy. Seven participants (46.7 percent) in the experimental group and 13 participants (86.7 percent) in the control group experienced tooth sensitivity (P < .05). The intensity of sensitivity was statistically significantly higher for participants in the control group (P < .05). CONCLUSIONS: The use of a desensitizing gel (5 percent nitrate potassium/2 percent sodium fluoride) before in-office bleaching did not affect the bleaching efficacy but did reduce tooth sensitivity. CLINICAL IMPLICATIONS: The use of a desensitizing gel before in-office tooth bleaching can reduce tooth sensitivity, the most common side effect associated with this procedure.