Application Tip and Concentration of a Self-mixing Bleach: Hydrogen Peroxide Inside the Pulp Chamber, Color Change, and Amount of Bleaching Gel Used.

PURPOSE: The objective of this study was to evaluate if the application method (tip with brush or tip without brush) and hydrogen peroxide (HP) concentration (6% or 35% self-mixing) of in-office bleaching gel influences the penetration of HP into the pulp chamber, color change, and the amount of bleaching gel used. METHODS: Forty healthy premolars were randomly divided into the following five groups (n=8): no treatment; HP6% using a tip with a brush, HP6% using a tip without a brush, HP35% using a tip with a brush, and HP35% using a tip without a brush. After treatments, the HP concentration (µg/mL) within the pulp chamber was determined using UV-Vis spectrophotometry. The color change (ΔEab, ΔE00, and ΔWID) was evaluated using a digital spectrophotometer. The amount of gel used (g) in each group was measured using a precision analytical balance. Data from each test were submitted to parametric tests (α=0.05). RESULTS: The tip with a brush resulted in a lower amount of HP inside the pulp chamber and less gel used when compared with the tip without a brush, regardless of HP concentration (p<0.05). However, regarding the tip used, although no significant difference was observed when HP35% was used (p>0.05), a higher whitening effect was observed when the 6% HP was applied without a brush as opposed to with a tip brush (p<0.05). CONCLUSIONS: The use of a tip with a brush, regardless of the in-office bleaching gel concentration (6% or 35% self-mixing), presented a lower penetration and lower volume of spent gel when compared to a tip without brush. However, the whitening effect depended on the concentration of HP used.

Color Changes Associated with Sandblasting, Hydrofluoric Acid Etching, and Er:YAG Laser Irradiation of Milled Feldspathic Porcelain Laminate Veneers.

OBJECTIVES: To evaluate color changes in milled feldspathic porcelain laminate veneers following hydrofluoric acid etching (HFA), sandblasting (SB), or Er:YAG laser irradiation (LI). METHODS AND MATERIALS: Disc-shaped specimens (thickness=1 mm, diameter=8 mm) were milled from feldspathic porcelain blocks (n=40). Glazed specimens were randomly assigned to four subgroups (n=10 each) according to surface treatment: negative control, HFA, SB, and LI. A layer of translucent, light-cured resin cement (thickness=0.1 mm) was then applied following silanization. The color was characterized by the L*, a*, and b* uniform color space (CIE) using a reflection spectrophotometer. CIEDE2000 (ΔE00) was calculated to determine the color difference between each surface treatment and negative control groups. Data were statistically analyzed using analysis of variance (ANOVA), Kruskal-Wallis, and Dunn-Bonferroni post hoc tests. RESULTS: There were no significant differences in CIEL* and CIEb* coordinates between negative control and all surface treatment groups (p≥0.108). The SB group demonstrated significantly lower mean CIEa* (higher greenish hue) compared to other groups (p≤0.003). HFA exhibited significantly higher CIEa* (closer to red) when compared to LI (p=0.039). LI induced the smallest overall color change compared to negative control (ΔE00=1.43 [1.07]). However, the differences in ΔE00 values were not statistically significant (p=0.648). CONCLUSIONS: The tested surface treatments did not affect the lightness or the yellowness of the 1-mm-thick milled feldspathic porcelain veneers. However, sandblasting resulted in a significant increase in the greenish hue. The Er:YAG laser resulted in the closest ΔE00 (1.43) to the 50:50% perceptibility threshold (ΔE00=1.2).

A meta-analysis of ozone effect on tooth bleaching.

This systematic review assessed the effectiveness of ozone (O3) in the color change of in-office tooth bleaching in vital teeth (TB) and the sensitivity control. Only randomized controlled clinical trials were included. Seven databases were used as primary search sources, and three additional sources were searched to capture the "grey literature" partially. The JBI tool was used to assess the risk of bias. TB was assessed using the ΔELab color change metric comparing tooth color pre- and post-bleaching. We meta-analyzed the ΔELab estimates per method and calculated the absolute standardized mean difference using random-effect models. The GRADE approach assessed the certainty of the evidence. The ΔELab estimates ranged from 1.28 when the O3 was used alone to 6.93 when combined with hydrogen peroxide (HP). Two studies compared O3 and HP alone, but their TB was similar (SMD = - 0.02; 95%CI: - 0.54; 0.49). The bleaching effectiveness for the combination of O3 + HP compared to HP was similar (SMD = 0.38; 95%CI: - 0.04; 0.81). Thus, based on the available literature, our findings suggest that O3 is not superior to the conventional technique using HP on the change of tooth color. The O3 did not present sensitivity when used alone. When O3 was used in combination with HP, patients reported hypersensitivity only when O3 was applied before HP, i.e., no sensitivity was perceived when O3 was applied after HP.

Effect of violet LED light on in-office bleaching protocols: a randomized controlled clinical trial.

Objective This study evaluated the clinical effect of violet LED light on in-office bleaching used alone or combined with 37% carbamide peroxide (CP) or 35% hydrogen peroxide (HP). Methodology A total of 100 patients were divided into five groups (n=20): LED, LED/CP, CP, LED/HP and HP. Colorimetric evaluation was performed using a spectrophotometer (ΔE, ΔL, Δa, Δb) and a visual shade guide (ΔSGU). Calcium (Ca)/phosphorous (P) ratio was quantified in the enamel microbiopsies. Measurements were performed at baseline (T 0 ), after bleaching (T B ) and in the 14-day follow-up (T 14 ). At each bleaching session, a visual scale determined the absolute risk (AR) and intensity of tooth sensitivity (TS). Data were evaluated by one-way (ΔE, Δa, ΔL, Δb), two-way repeated measures ANOVA (Ca/P ratio), and Tukey post-hoc tests. ΔSGU and TS were evaluated by Kruskal-Wallis and Mann-Whitney, and AR by Chi-Squared tests (a=5%). Results LED produced the lowest ΔE (p<0.05), but LED/HP promoted greater ΔE, ΔSGU and Δb (T 14 ) than HP (p<0.05). No differences were observed in ΔE and ΔSGU for LED/CP and HP groups (p>0.05). ΔL and Δa were not influenced by LED activation. After bleaching, LED/CP exhibited greater Δb than CP (p>0.05), but no differences were found between these groups at T 14 (p>0.05). LED treatment promoted the lowest risk of TS (16%), while HP promoted the highest (94.4%) (p<0.05). No statistical differences of risk of TS were found for CP (44%), LED/CP (61%) and LED/HP (88%) groups (p>0.05). No differences were found in enamel Ca/P ratio among treatments, regardless of evaluation times. Conclusions Violet LED alone produced the lowest bleaching effect, but enhanced HP bleaching results. Patients treated with LED/CP reached the same efficacy of HP, with reduced risk and intensity of tooth sensitivity and none of the bleaching protocols adversely affected enamel mineral content.

Impact of transparent tray-based application of bioactive glasses desensitizer on the permeability of enamel and dentin to hydrogen peroxide: an in vitro study.

BACKGROUND: To investigate the effect of transparent tray-based application of bioactive glasses (BGs) desensitizer on the permeability of enamel and dentin to hydrogen peroxide (H2O2). METHODS: Freshly extracted human first premolars were divided into 6 groups (n = 8). Group A and B: without pretreatments; Group C and E: treated with BGs desensitizer only; Group D and F: treated with BGs desensitizer dispensed with a transparent tray. After roots and pulp tissues of the treated tooth specimens were thoroughly removed, acetate buffer was added into pulp chambers and the treated specimens were immersed in distilled water (Groups A, E, and F) or 30% H2O2 (Groups B, C, and D) for 30 min at 37 °C. The amount of H2O2 in the pulp chamber of each group was measured using ultraviolet-visible spectrophotometry. RESULTS: In control groups (Group A, E, and F), H2O2 was not detected. The amount of pulpal H2O2 in Group B, C, and D were 21.149 ± 0.489 µg, 9.813 ± 0.426 µg, and 4.065 ± 0.268 µg respectively. One-way ANOVA analysis indicated that significant differences existed in these groups (F = 459.748, p < 0.05). CONCLUSIONS: The effect of BGs desensitizer in reducing the permeability of enamel and dentin to H2O2 could be enhanced when dispensed with a transparent tray.

Clinical Evaluation of In-Office Dental Bleaching Using a Violet Light-Emitted Diode.

Objective: To clinically evaluate the effect of the violet light-emitted diode (LED) light (405-410 nm) associated to in-office dental bleaching with 35% carbamide peroxide, on tooth color change and sensitivity. Participant's satisfaction after treatment was also evaluated. Materials and methods: A total of 50 participants were selected and randomized into a treatment group (n = 25): G1-two bleaching sessions of 30 min each, with 7-day interval (D0 and D7); G2-two bleaching sessions (same protocol as G1) associated with violet LED light, 30 min each session. The color evaluation was performed before and after 7 days of the second session (D0 and D14); the medium third of buccal surface of canine and central incisor teeth were evaluated under VITA Shade Guide and spectrophotometry (subjective and objective). Tooth sensitivity was evaluated immediately after the treatment and after 48 h of each bleaching session (D0, D2, D7, and D9), and a self-perception questionnaire was applied on D14. Results: Data were subjected to nonparametric Mann-Whitney test and both canine and central incisor teeth presented color change. Group G2 showed significantly more change than G1. Fisher's exact test showed no statistically significant dental sensitivity differences between groups. Both groups reported a high level of satisfaction but chi-square test showed statistically higher satisfied patients with dental bleaching in G2 than G1. Conclusions: The violet LED light (405-410 nm) could improve dental bleaching effectiveness, without sensitivity increase.

Conhecendo a terapia clareadora: efeito do local de aplicação e do volume de gel clareador na alteração cromática e sensibilidade pós-operatória: estudo clínico randomizado / Knowing the whitening therapy: effect of the application site and the volume of whitening gel on the chromatic alteration and postoperative sensitivity: randomized clinical trial

Embora o sucesso do clareamento dental tenha sido considerado dependente da dosagem utilizada, este procedimento ainda é cercado de importantes lacunas no que se refere à posologia utilizada e a forma de aplicação dos produtos clareadores. O objetivo deste estudo foi avaliar clinicamente o efeito do posicionamento do gel clareador e a influência de seu volume na alteração cromática e sensibilidade pósoperatória. Para o estudo referente ao posicionamento do gel clareador, trinta pacientes foram selecionados e alocados em três grupos (n=10): GI-aplicação na metade cervical, GII- aplicação na metade incisal, GIII- aplicação em toda a face vestibular. A quantidade e o tempo de aplicação do gel Peróxido de Hidrogênio a 35% foram padronizados. A análise de cor foi realizada pelo ΔE e WID (índice de clareamento), utilizando os valores obtidos pelas leituras realizadas em espectrofotômetro digital. As leituras foram realizadas nas regiões cervical e incisal dos dentes. A sensibilidade espontânea foi avaliada por questionário e a sensibilidade provocada através da análise termosensorial (TSA). As análises foram realizadas em 5 tempos: baseline, após 1º sessão clareadora (S), 2ºS e 3ºS e 14 dias após o término do clareamento. Os dados foram analisados pelo modelo de regressão linear com efeitos mistos e pós-teste por contrastes ortogonais (p< 0,05). Pode-se observar que, em relação à alteração cromática, apesar da região incisal ser momentaneamente favorecida pela aplicação do gel, ao final do tratamento, a restrição do local de aplicação à região cervical ou incisal proporcionaram resultados semelhantes aos obtidos quando o gel foi aplicado em toda a face vestibular. Quanto à sensibilidade, apenas o grupo que recebeu gel clareador na porção cervical apresentou sensibilidade espontânea. Já na análise termosensorial, o grupo que recebeu gel na face vestibular exerceu menor influência no limiar de sensação térmica. Paralelamente, no segundo estudo, em que se avaliou a influência do volume de gel clareador, os trinta pacientes foram alocados em três grupos: GI- 0,025mL, GII-0,05mL, GIII-0,10mL, e receberam o produto apenas nos caninos inferiores (n=10). A análise da alteração cromática foi realizada utilizando um espectrofotômetro digital portátil, sendo calculados os valores de ΔE, ΔL*, Δa*, Δb*, bem como o índice de clareamento (WID). A sensibilidade espontânea foi avaliada por aplicação de questionário e a sensibilidade provocada através da análise termosensorial. As análises foram realizadas em 5 tempos: baseline, após 1º, 2º e 3º sessões clareadoras e 14 dias após o término. Os dados foram analisados pelos testes Anova dois fatores com medidas repetidas e pós-teste de Tukey (p< 0,05). Observouse que o ΔE e o ΔL* foram semelhantes entre os grupos ao final da terapia clareadora. Os valores de Δa*, Δb*, bem com o WID foram mais intensos no grupo que recebeu 0,10mL, que também apresentou a maior sensibilidade espontânea e estimulada. Assim, através dos dois estudos realizados, pode-se concluir que ao final do tratamento, a alteração cromática independe do local de aplicação do gel clareador, entretanto, a região incisal, apresenta saturação cromática mais rápida que a região cervical. Constatou-se também que quanto maior o volume, maior a resposta clareadora nas coordenadas especificas e no índice de clareamento, entretanto, não apresentando diferença na alteração cromática e na luminosidade analisada. Já a sensibilidade dental foi mais intensa quando a aplicação do gel foi concentrada na região cervical, sendo também marcadamente proporcional ao volume empregado. Com isso, em relação ao grupo dental analisado, a redução do posicionamento do gel clareador para a incisal e a utilização de um volume intermediário (0,05mL), proporcionaram efeitos positivos para a alteração cromática e redução da resposta de sensibilidade(AU)

Although the success of tooth whitening was considered to be dependent on the dosage used, this procedure still has important gaps with regard to the dosage used and the form of application of the whitening products. The aim of this study was to evaluate clinically the effect of the positioning of the bleaching gel and the influence of its volume on the chromatic alteration and on the postoperative sensitivity. For the study of the positioning of the bleaching gel, thirty patients were selected and allocated into three groups (n = 10): GI- application on the cervical half, GII- application on the incisal half, GIII- application on the entire buccal surface. The amount and time of application of the 35% hydrogen peroxide gel were standardized. The color analysis was performed by ΔE and WID (lightening index), using the values obtained in the readings performed on a digital spectrophotometer. The readings were made in the cervical and incisal regions of the teeth. Spontaneous sensitivity was assessed using a questionnaire and the sensitivity caused by thermo-sensory analysis (TSA). The analyzes were carried out in 5 stages: baseline, after the 1st whitening session (S), 2ºS and 3ºS and 14 days after the end of the whitening. The data were analyzed using the linear regression model with mixed effects and post-test using orthogonal contrasts (p < 0.05). It can be seen that, regarding the chromatic alteration, although the incisal region is momentarily favored by the application of the gel, at the end of the treatment the restriction of the application site to the cervical or incisal region provided results similar to those obtained when the gel was applied throughout the vestibular face. As for sensitivity, only the group that received whitening gel in the cervical portion had spontaneous sensitivity. In the thermosensory analysis, the group that received gel on the vestibular face had less influence on the threshold of thermal sensation. In parallel, in the second study, in which the influence of the volume of the bleaching gel was evaluated, the thirty patients were allocated into three groups: GI-0.025mL, GII0.05mL, GIII-0.10mL, and received the product only in lower canines (n = 10). The chromatic alteration analysis was performed using a portable digital spectrophotometer, being calculated the values of ΔE, ΔL *, Δa *, Δb *, as well as the bleaching index (WID). Spontaneous sensitivity was assessed by applying a questionnaire and sensitivity by thermo-sensory analysis. The analyzes were carried out in 5 stages: baseline, after 1st, 2nd and 3rd whitening sessions and 14 days after the end. Data were analyzed using two-way ANOVA tests with repeated measures and Tukey's post-test (p < 0.05). It was observed that ΔE and ΔL * were similar between the groups at the end of the bleaching therapy. The values of Δa *, Δb *, as well as the WID were more intense in the group that received 0.10mL, which also showed the highest spontaneous and stimulated sensitivity. Thus, through the two studies carried out, it can be concluded that at the end of the treatment the chromatic alteration does not depend on the application site of the whitening gel, however, the incisal region, presents chromatic saturation faster than the cervical region. It was also found that the greater the volume, the greater the bleaching response in the specific coordinates and in the bleaching index, however, showing no difference in the chromatic alteration and in the analyzed luminosity. The tooth sensitivity was more intense when the application of the gel was concentrated in the cervical region, being also markedly proportional to the volume used. Thus, in relation to the analyzed dental group, the reduction of the positioning of the bleaching gel to the incisal and the use of an intermediate volume (0.05mL), provided positive effects for the chromatic alteration and reduction of the sensitivity response(AU)

Effect of violet LED light on in-office bleaching protocols: a randomized controlled clinical trial

Abstract Objective This study evaluated the clinical effect of violet LED light on in-office bleaching used alone or combined with 37% carbamide peroxide (CP) or 35% hydrogen peroxide (HP). Methodology A total of 100 patients were divided into five groups (n=20): LED, LED/CP, CP, LED/HP and HP. Colorimetric evaluation was performed using a spectrophotometer (ΔE, ΔL, Δa, Δb) and a visual shade guide (ΔSGU). Calcium (Ca)/phosphorous (P) ratio was quantified in the enamel microbiopsies. Measurements were performed at baseline (T 0 ), after bleaching (T B ) and in the 14-day follow-up (T 14 ). At each bleaching session, a visual scale determined the absolute risk (AR) and intensity of tooth sensitivity (TS). Data were evaluated by one-way (ΔE, Δa, ΔL, Δb), two-way repeated measures ANOVA (Ca/P ratio), and Tukey post-hoc tests. ΔSGU and TS were evaluated by Kruskal-Wallis and Mann-Whitney, and AR by Chi-Squared tests (a=5%). Results LED produced the lowest ΔE (p<0.05), but LED/HP promoted greater ΔE, ΔSGU and Δb (T 14 ) than HP (p<0.05). No differences were observed in ΔE and ΔSGU for LED/CP and HP groups (p>0.05). ΔL and Δa were not influenced by LED activation. After bleaching, LED/CP exhibited greater Δb than CP (p>0.05), but no differences were found between these groups at T 14 (p>0.05). LED treatment promoted the lowest risk of TS (16%), while HP promoted the highest (94.4%) (p<0.05). No statistical differences of risk of TS were found for CP (44%), LED/CP (61%) and LED/HP (88%) groups (p>0.05). No differences were found in enamel Ca/P ratio among treatments, regardless of evaluation times. Conclusions Violet LED alone produced the lowest bleaching effect, but enhanced HP bleaching results. Patients treated with LED/CP reached the same efficacy of HP, with reduced risk and intensity of tooth sensitivity and none of the bleaching protocols adversely affected enamel mineral content.

Effect of gel replacement during in-office dental bleaching: a case report.

In-office dental bleaching allows the dentist to have greater control of the procedure and prevents patients from ingesting chemicals. To obtain optimum results, in-office bleaching usually requires a longer period of application as well as changes of the bleaching agent applied to the tooth surfaces at each appointment. The objective of this case report was to assess, by means of a split-mouth design in a single patient, the final tooth color and tooth sensitivity resulting from 2 different bleaching protocols: 1 application of 35% hydrogen peroxide for 45 minutes and 3 applications of 35% hydrogen peroxide for 15 minutes each. Neither the patient nor 5 individuals who were blinded to the techniques noted a difference in the final esthetic results of the 2 protocols immediately after the procedure. In addition, the patient reported that no tooth sensitivity was associated with either protocol. The results of dental bleaching on both sides were maintained after 15 days. The results shown in the present case report suggest that there may be no need to renew the gel during in-office dental bleaching.

Hydrogen peroxide-based products alter inflammatory and tissue damage-related proteins in the gingival crevicular fluid of healthy volunteers: a randomized trial.

Hydrogen peroxide (H2O2)-based products are effective in tooth whitening; however, their safety is controversial as they may harm patient tissues/cells. These effects are suggested to be concentration-dependent; nonetheless, to date, there are no reports on H2O2-mediated oxidative damage in the gingival tissue, and neither whether this can be detected in gingival crevicular fluid (GCF) samples. We hypothesize that H2O2 whitening products may cause collateral oxidative tissue damage following in office application. Therefore, H2O2 and nitric oxide (NO) levels were investigated in GCF samples obtained from patients undergoing dental bleaching with H2O2 at different concentrations, in a randomized, double-blind, split-mouth clinical trial. A proteomic analysis of these samples was also performed. H2O2-based whitening products promoted inflammation which was detected in GCF samples and lasted for longer following 35% H2O2 bleaching. This included time-dependent changes in NO levels and in the abundance of proteins associated with NO synthesis, oxidative stress, neutrophil regulation, nucleic acid damage, cell survival and/or tissue regeneration. Overall, H2O2-based products used in office promote inflammation irrespective of their concentration. As the inflammation caused by 35% H2O2 is longer, patients may benefit better from using lower concentrations of this bleaching product, as they may result in less tissue damage.

In vivo and in vitro assessment of the bleaching effectiveness of a brush-off patch containing 3.0% hydrogen peroxide.

OBJECTIVES: To evaluate the efficacy of a brush-off patch containing 3.0% hydrogen peroxide, which is a new over-the-counter (OTC) product for tooth whitening, and determine the optimal protocol for use. MATERIALS AND METHODS: We performed an in vitro study using hydroxyapatite specimens and a clinical trial involving 140 volunteers. The brush-off patch was applied to the specimens (in vitro) or the maxillary anterior teeth (in vivo; 14 days) for 10 min twice daily (case 10 group) or 30 min once daily (case 30 group). We also included control groups in both experiments. Lightness (L*), redness (a*), and yellowness (b*) values were measured using a colorimeter. In the in vivo study, color changes were measured at baseline and 7 and 14 days after the start of patch application. The overall color change (ΔE) was statistically analyzed. RESULTS: In the in vitro study, the color change (ΔE*) after the experiment was significantly different between the two case groups and the control group (p < 0.001). In the in vivo study, the case groups showed color changes at both 7 and 14 days after patch application. In particular, the change in the case 30 group was significantly more prominent on day 14 than on day 7 (p < 0.05). CONCLUSION: Our findings suggest that brush-off patches containing 3.0% hydrogen peroxide are effective OTC products for tooth whitening. CLINICAL RELEVANCE: For best results, brush-off patches containing 3.0% hydrogen peroxide can be applied once daily for 30 min.

Effect of photobiomodulation with low-level laser therapy combined with potassium nitrate on controlling post-bleaching tooth sensitivity: clinical, randomized, controlled, double-blind, and split-mouth study.

OBJECTIVES: To evaluate the effect of photobiomodulation with low-level laser therapy (PBM-LLLT) combined with 5% potassium nitrate (KNO3) on controlling tooth sensitivity (TS) after in-office tooth bleaching. MATERIALS AND METHODS: Fifty volunteers were selected based on the inclusion and exclusion criteria and were randomly allocated into four groups: G1 (control): placebo gel application, 35% hydrogen peroxide bleaching (HP35) and mock PBM-LLLT without light emission; G2: placebo gel application, bleaching with HP35 and PBM-LLLT; G3: application of KNO3, bleaching with HP35 and mock PBM-LLLT; and G4: application of KNO3, bleaching with HP35 and PBM-LLLT. A pain assessment questionnaire was used to evaluate TS during the 21 days of treatment. The Friedman test was used for intragroup analysis, and the Wilcoxon and Mann-Whitney tests were used for intergroup comparisons. RESULTS: The intragroup evaluation showed significant differences among the evaluation times in all groups (p ≤ 0.05). The highest pain sensitivity levels were recorded on the 1st, 8th, and 15th days. In G1, TS manifested for up to 3 days after each bleaching session, while G2, G3, and G4 presented TS only on the days of the bleaching sessions. Intergroup analysis showed that TS manifestation differed significantly between G1 and the other groups (p ≤ 0.05) but did not differ significantly among G2, G3, and G4 (p ≥ 0.05). CONCLUSION: PBM-LLLT and KNO3 are effective at reducing pain sensitivity after tooth bleaching, but no synergistic effect between these treatments was observed for the different evaluation periods. CLINICAL RELEVANCE: The effect of PBM-LLLT combined with KNO3 on post-bleaching tooth sensitivity is similar to their individual use alone.

Clinical evaluation of color change and tooth sensitivity with in-office and home bleaching treatments.

BACKGROUND: Among the number of vital bleaching techniques currently available to the clinicians, home bleaching and in-office bleaching are widely used in dental practice. AIM AND OBJECTIVES: The aim of this in vivo study was to compare the clinical performance, durability, and related tooth sensitivity with two vital bleaching procedures (in-office and at-home bleaching), in a split-mouth design. PATIENTS AND METHODS: Thirty adult participants having teeth shade mean of A2 or darker were selected for the study. One-half of the maxillary arch of each patient received in-office bleaching with 35% hydrogen peroxide gel, and the other half received 16% carbamide peroxide night guard bleaching. Shade evaluation was done with shade guide and spectrophotometer at 1, 2, 3, and 4 week intervals during bleaching and postoperatively at 3 and 6 month intervals. Tooth sensitivity was recorded using the visual analog scale during the experimental period. STATISTICAL ANALYSIS: Collected data of color and sensitivity readings were subjected to statistical analysis using SPSS/PC version 20 software. Intergroup comparison through unpaired t-test and within the groups using paired t-test was done. RESULTS: At-home and in-office bleaching procedures are equally effective in producing tooth whitening. Color evaluation after 3 and 6 months showed more color decline for in-office bleaching procedure. For sensitivity parameter also, in-office procedure recorded higher sensitivity compared to home bleaching (P < 0.05). CONCLUSION: Both the bleaching procedures are equally effective in producing tooth whitening. In-office bleaching recorded higher levels of tooth sensitivity and greater color rebound than home bleaching.

High-concentration carbamide peroxide can reduce the sensitivity caused by in-office tooth bleaching: a single-blinded randomized controlled trial.

Objectives A single-blinded, randomized, parallel clinical trial evaluated the use of 37% carbamide peroxide (CP) on bleaching effectiveness and tooth sensitivity reported by patients undergoing in-office tooth bleaching, in comparison with the results of using 35% hydrogen peroxide. Material and Methods Forty patients were allocated to receive two sessions of in-office tooth bleaching using either 35% hydrogen peroxide (HP) or 37% CP. Each patient's sensitivity level was evaluated during and up to 24 h after bleaching. The effectiveness of the bleaching procedures was evaluated with a spectrophotometer one week after each session and 30 days after the last session. The impact of tooth bleaching on the patients' perceptions regarding smile changes, in addition to the bleaching procedures and their results, were also recorded. Absolute and relative sensitivity risks were calculated. Data on sensitivity level were analyzed using the Mann-Whitney or T-test, and data from the color evaluation were subjected to 2-way repeated measures ANOVA. Results The use of CP reduced the risk and level of tooth sensitivity to values close to zero, whereas the difference between the bleaching agents disappeared after 24 h. An increased bleaching effect was observed for HP, mainly due to an improved reduction of redness and yellowness. Participants perceived improved tooth bleaching for HP and reduced sensitivity for CP, but no differences regarding the comfort of the techniques were noted. Conclusions In our study, 37% CP resulted in reduced tooth sensitivity but decreased the tooth bleaching effectiveness. However, both bleaching agents resulted in high levels of patient satisfaction.

Quality of life and stability of tooth color change at three months after dental bleaching.

PURPOSE: Intracoronary bleaching is a minimally invasive, alternative treatment that addresses aesthetic concerns related to non-vital teeth discoloration. However, to the best of our knowledge, no studies have assessed the psychosocial impacts of such procedures on patients' aesthetic perceptions. The aim of this study was to evaluate aesthetic perceptions and the psychosocial impact of patients up to 3 months after their teeth had been bleached with hydrogen peroxide (35%) and carbamide peroxide (37%) using the walking bleach technique. METHODS: The patients were randomly divided into two groups according to the bleaching agent used: G1 = hydrogen peroxide 35% (n = 25) and G2 = carbamide peroxide 37% (n = 25). Non-vital bleaching was performed in four sessions. Color was objectively (ΔE) and subjectively (ΔSGU) evaluated. Aesthetic perception and psychosocial factors were evaluated before, 1 week and 1 month after the bleaching using the Oral Health Impact Profile (OHIP) and Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) questionnaires. RESULTS: The color change (ΔE) values at 1 month were G1 = 16.80 ± 6.07 and G2 = 14.09 ± 4.83. These values remained stable until the third month after treatment (p > 0.05). There was a decrease in the values of OHIP-aesthetics and PIDAQ after treatment versus baseline (p < 0.05). This status was maintained through the third month after treatment. CONCLUSIONS: Both agents were highly effective and had a positive impact on the aesthetic perception and psychosocial impact of patients, values that also remained stable over time. Non-vital bleaching yields positive and stable impacts on aesthetic perception and psychosocial factors. ClinicalTrials.gov identifier NCT02718183.

Tooth whitening efficacy of pigmented rice gels containing carbamide peroxide.

Carbamide peroxide (CP) is commonly used as a tooth whitening agent. However, efficacy of CP can be enhanced if it is in the suitable delivery system. In the present study, CP loaded in pigmented rice gels were developed and investigated for their physicochemical properties and tooth whitening efficacy. The modified pigmented rice of two varieties, Homnil (HN) and Doisket (DS) were prepared and used as a gelling agent. The outer appearance of the obtained rice gels containing 10% CP (CP-HN and CP-DS, respectively) were transparent and homogeneous texture. The pH of both rice gel bases was neutral but became slightly acidic after incorporating with CP. The adhesive property of HN gel was significantly higher than DS gels. In vitro drug release profile exhibited that the release of CP from CP-DS was significantly higher than CP-HN and the commercial gel (CP-CG), respectively. In vitro tooth whitening efficacy in 45 normal teeth revealed that the tooth whitening efficacy of the gels was time dependent. At the end of the treatment, CP-HN showed significantly higher tooth whitening efficacy than CP-DS and CP-CG, respectively. It is concluded that the physicochemical properties, particularly the adhesive and dissolution properties, play an important role in the tooth whitening efficacy of the CP gels.

In-office tooth bleaching with 38% hydrogen peroxide promotes moderate/severe pulp inflammation and production of ll-1ß, TNF-ß, GPX, FGF-2 and osteocalcin in rats.

OBJECTIVES: To study the intensity of inflammatory infiltrate and production of interleukin-1ß (ll-1ß), tumor necrosis factor-ß (TNF-ß), fibroblast growth factor-2 (FGF-2), glutathione peroxidase (GPX), and osteocalcin in response to in-office tooth bleaching in rats. MATERIAL AND METHODS: Twenty male Wistar rats were randomized into four groups (n=5) according to the received treatment (tooth bleaching or no treatment - control) and the period of euthanasia after treatment (24 h or 10 days). We performed tooth bleaching using a 38% hydrogen peroxide gel on maxillary and mandibular incisors. After euthanasia, incisors (20 per group) were processed for histological analysis, immunohistochemistry staining of ll-1ß, TNF-ß, FGF-2 and GPX and osteocalcin by immunofluorescence. We analyzed data using the Mann-Whitney and Kruskal-Wallis/Dunn tests (p<0.05). RESULTS: The bleached groups presented statistically significant differences regarding the pulp inflammation stage compared with the control groups. Bleached teeth showed moderate/severe inflammatory infiltrate and control groups presented absent inflammatory cells or a negligible number of mononuclear cells (p<0.001) at two times (24 h and 10 days). There was strong staining for ll-1ß, TNF-ß, and GPX in bleached groups at 24 h and strong staining for ll-1ß, TNF-ß, GPX and FGF-2 at 10 days. After 10 days of tooth bleaching, the bleached group showed a statistically superior amount of osteocalcin than the other groups (p<0.01). CONCLUSIONS: Tooth bleaching with 38% hydrogen peroxide causes severe pulp inflammation, but characteristics of tissue repair after 10 days.

Effectiveness of In-office Hydrogen Peroxide With Two Different Protocols: A Two-center Randomized Clinical Trial.

OBJECTIVES: The aim of this study was to compare the bleaching efficacy and tooth sensitivity (TS) of a 38% hydrogen peroxide bleaching agent used for in-office bleaching, applied under different time protocols: a 40-minute application or two 20-minute applications. METHODS AND MATERIALS: Forty-four patients from Brazil and Colombia, with right superior canines darker than C2, were selected for this multicenter, single-blind, randomized trial. The teeth were bleached in two sessions, with a one-week interval between them, in a split-mouth design. The bleaching agent was applied in two 20-minute (2×20) applications or one 40-minute (1×40) application in each session according to the manufacturer's instructions. The color changes were evaluated by using subjective (Vita Classical and Vita Bleachedguide) and objective (Easyshade Spectrophotometer) methods at baseline and 30 days after the second session. Tooth sensitivity was recorded up to 48 hours with a 0-10 visual analog scale. Also, the pH values during the application of bleaching were recorded. Color change in shade guide units and ΔE were analyzed by using the Student t-test (α=0.05). The absolute risk and intensity of TS were evaluated with the McNemar test, the Wilcoxon signed-rank test, and the Friedman test, respectively (α= 0.05). RESULTS: Significant whitening was observed in both groups after 30 days of clinical evaluation. The use of a 40-minute application did not significantly influence the absolute risk of TS (68%, 95% confidence interval [CI] = 53-80) as well as the intensity of TS compared with the acid bleaching gel (absolute risk of 82%, 95% CI = 68-91). The pH values did not differ significantly between groups and at the different assessment periods ( p=0.42). CONCLUSION: The use of a 40-minute in-office bleaching agent gel application produced the same whitening degree and TS that the two 20-minute bleaching agent applications did. The former preferably should be applied because one 40-minute application does not require gel refreshing.

Color stability, psychosocial impact, and effect on self-perception of esthetics of tooth whitening using low-concentration (6%) hydrogen peroxide.

OBJECTIVE: The aim of this study was to assess the bleaching efficacy and impact on psychosocial and esthetics self-perception of a low-concentration (6%) hydrogen peroxide (H2O2) gel compared with a conventional (37.5%) H2O2 gel when used as an in-office treatment. METHOD AND MATERIALS: In total, 35 participants received two sessions of three 12-minute applications of treatment with 37.5% H2O2 on one side of the mouth and 6% H2O2 on the other. Color changes were measured objectively using total variation in color (ΔE) and subjectively using Vita Classical scale (ΔSGU). The Psychosocial Impact of Dental Aesthetic Questionnaire (PIDAQ) and Oral Health Impact Profile (OHIP-14) esthetic questionnaires were administered to measure self-perception and the psychosocial impact of the whitening procedure. RESULTS: Both gels produced significant changes in tooth color at 1 and 3 months post-whitening. The objective efficacy (ΔE) of 37.5% H2O2 (9.06 ± 2.96) was significantly higher than that of 6% H2O2 (5.69 ± 3.06). The results of the subjective assessment were not statistically different. There was a positive impact on esthetic auto perception (OHIP-14, P < .05) and psychosocial impact (PIDAQ, P < .05) at the 3-month time point. CONCLUSION: Low concentration of H2O2 (6%) achieved effective bleaching (ΔE > 5 units) with good stability at 3 months accompanied by a positive psychosocial impact and enhanced self-perception. However, the traditional 35% concentration was objectively more effective.

Home Dental Bleaching Monitored With Microelectronic Sensors to Record the Wearing Times of an Acetate Tray/Bleaching Product.

The present case study quantifies the clinical wearing time of an acetate tray/bleaching product during home dental bleaching. The patient was instructed to use a 10% carbamide peroxide gel for 6-8 hours each day for 20 days. The wearing time of the tray was measured by a microsensor from TheraMon microelectronic system (Sales Agency Gschladt, Hargelsberg, Austria) completely embedded in the tray so that the clinician would be informed as to the precise time the tray was placed in the mouth. Evaluation of the daily printout during dental bleaching demonstrated that the patient did not correctly follow the clinician's instructions as to the wearing time of the tray. Recording the wearing time of dental bleaching agents can be beneficial for both dental professional and patient to obtain a more effective treatment according to the patient's needs and expectations.