Is a White Diet Necessary for Tooth Bleaching Procedures? A Systematic Review and Meta-Analysis.

The aim of this investigation was to conduct a systematic review and meta-analysis to determine the necessity of a white diet during or following a bleaching procedure. This systematic review and meta-analysis followed the PRISMA guidelines meticulously. The research question was: Is a white diet necessary during and/or after a bleaching treatment? In vitro studies or clinical trials reporting the color change in bleached enamel after the use of a free-staining diet were considered for full-text review. For the analyses, a random-effects model was employed. Statistical significance was defined as a p-value < 0.05. A total of 17 documents were eligible for qualitative analysis: 5 clinical trials and 12 in vitro studies. Only data from the clinical trials were included in the meta-analysis. For at-home bleaching, differences in the color among the subjects were not statistically significant during the first (p = 0.64), second (p = 0.26) or third (p = 0.43) weeks of treatment. Also, the color difference one month after finishing the bleaching treatment were not statistically significant (p = 0.27). The color difference one month after finishing an in-office treatment showed that the restrictions on diet did not significantly improve the bleaching outcomes (p = 0.90). According to the findings of this review, dietary restrictions are not necessary during or after bleaching procedures.

Effect of At-Home Versus Over-the-Counter Bleaching Agents on Enamel Color, Roughness, and Color Stability.

Background This study was designed to evaluate the efficacy of standard at-home bleaching agents in comparison to new over-the-counter (OTC) products on human enamel regarding color change, color stability, and surface roughness. Methodology A total of 80 extracted adult human maxillary central incisors were prepared and arbitrarily divided into the following four equal groups (N =20): group A: at-home opalescence boost containing 15% carbamide peroxide (CP); group B: crest whitening strips containing 6% hydrogen peroxide (HP); group C: light-emitted diode (LED) home tray with 20% CP + 4% HP; and group D: white and black toothpaste containing active charcoal components. Tooth color was measured using a spectrophotometer. Enamel surface roughness using a three-dimensional optical profilometer was measured before and after the bleaching procedure. To assess color stability, each bleached group was further subdivided into two equal subgroups (n = 10) according to the immersion media of either coffee or tea. Finally, the color was measured after 24 hours of immersion. Results All groups showed improvement in color from the baseline. The crest whitening strips group showed the lowest color improvement in comparison to all other groups. After staining, group C showed the lowest mean color change value ∆E2. No statistically significant difference was noted in surface roughness among all groups. Conclusions All OTC bleaching products as well as at-home bleaching improve teeth color and increase roughness on the enamel surface. Staining media has an adverse effect on the teeth after bleaching. The LED home tray showed a better whitening effect and color stability after bleaching.

Effect of whitening products on sound enamel and on artificial caries lesions during a cariogenic challenge.

OBJECTIVE: To investigate the effect of fluoride-containing whitening products on sound enamel and on artificial caries lesions during a cariogenic challenge. MATERIALS AND METHODS: Bovine enamel specimens (n = 120) with three areas [non-treated sound enamel (NSE), treated sound enamel (TSE), and treated artificial caries lesion (TACL)] were randomly assigned to the four groups: whitening mouthrinse (WM: 2.5% hydrogen peroxide-100 ppm F-), placebo mouthrinse (PM: 0% hydrogen peroxide-100 ppm F-), whitening gel (WG: 10% carbamide peroxide-1130 ppm F-), and deionized water (negative control; NC). The treatments (2 min for WM, PM, and NC, and 2 h for WG) were carried out during a 28-day pH-cycling model (6 × 60 min demineralization/day). Relative surface reflection intensity (rSRI) and transversal microradiography (TMR) analyses were performed. Fluoride uptake (surface and subsurface) was measured in additional enamel specimens. RESULTS: For TSE, a higher value of rSRI was observed in WM (89.99% ± 6.94), and a greater decrease in rSRI was observed for WG and NC, and no sign of mineral loss was verified for all groups (p > 0.05). For TACL, rSRI significantly decreased after pH-cycling for all experimental groups with no difference between them (p < 0.05). Higher amounts of fluoride were found in WG. WG and WM exhibited intermediate values of mineral loss, similar to PM. CONCLUSIONS: The whitening products did not potentialize the enamel demineralization under a severe cariogenic challenge, and they did not exacerbate mineral loss of the artificial caries lesions. CLINICAL RELEVANCE: Low concentrated hydrogen peroxide whitening gel and mouthrinse containing fluoride do not intensify the progression of caries lesions.

Chemical behavior of 20%-22% carbamide peroxide gels in at-home bleaching: Randomized crossover in situ trial.

OBJECTIVE: To evaluate if distinct 20%-22% carbamide peroxide bleaching gels present similar decomposition pattern and pH during the clinical use in both arches, as well as gels viscosity. METHODS: Participants randomly received treatments with carbamide peroxide gels (n = 10): OPF (OpalescencePF-20%); PNT (Polanight-22%); and WPC (Whiteness Perfect-22%) in three different days, with 2-day washout. Decomposition pattern was assessed by peroxide concentration. Both PC and pH of bleaching gels were measured in different time points in upper and lower trays during a total of 120 min of clinical use. Viscosity of bleaching gels was measured in triplicate. ANOVA and Tukey's test were applied (α = 0.05). RESULTS: Regarding decomposition pattern, no significant differences were observed for the interaction between gel, time, and tray position factors. The peroxide concentration progressively reduced until 120 min of trays use (p < 0.001), being overall more notable in lower trays (p < 0.001). Regarding pH, the lowest values were verified in WPC within time. At 120 min, an increase of pH was observed for both WPC and OPF (p < 0.001) compared to baseline means. PNT exhibited constant pH values over time. The values of viscosity were: OPF (1.682.000 ± 19 cP)a, WPC (1.388.667 ± 172.63 cP)ab, PNT (579.567 ± 0.98 cP)b. CONCLUSIONS: The bleaching gels presented overall decomposition pattern clinically equivalent, being more notable in lower trays over time. Nevertheless, distinct pH and viscosities were observed among the products. CLINICAL SIGNIFICANCE: Although the manufacturers recommend different times of use for bleaching gels with similar peroxide concentrations, the commercial products tested did not exhibit clinically relevant difference in the decomposition pattern during the 120 min of clinical procedure.

Clinical effects of the exposure to red wine during at-home bleaching.

OBJECTIVES: This clinical trial evaluated the effects of red wine exposure on the effectiveness of at-home bleaching with 10% carbamide peroxide, degree of tooth sensitivity, and levels of periodontal inflammatory markers. METHOD AND MATERIALS: Eighty participants were assigned to two groups, namely, those who drank red wine (experimental group), and those who did not drink red wine (control group). The experimental group participants rinsed their mouths with 25 mL of red wine four times a day during the bleaching period. Shade evaluation was assessed visually by using the Vita Classical and Vita Easyshade techniques. Tooth sensitivity was evaluated by the numeric and visual analog scales, and the salivary and gingival crevicular fluids were collected for assessment of nitric oxide (NO) levels, a marker of inflammation. Differences in color change were analyzed by one-way analysis of variance (ANOVA). The absolute risks of tooth sensitivity were compared by the Fisher exact test. Tooth sensitivity intensity data sets for both the visual analog scale and the numeric rating scale were compared using the Wilcoxon signed rank test (α = .05). Repeated measures and two-way ANOVA followed by the Bonferroni test were used to assess time-course and differences between groups in NO production. RESULTS: The bleaching technique was effective regardless of wine consumption (P > .05). Tooth sensitivity was classified as mild, with no differences between groups (P > .05). Red wine reduced both the gingival crevicular fluid and salivary levels of NO (P < .05). CONCLUSION: Red wine does not interfere with the effectiveness and sensitivity of at-home teeth bleaching with 10% carbamide peroxide and protects against bleaching-induced inflammation.

A Comparative Evaluation of Nanohydroxyapatite-Enriched Hydrogen Peroxide Home Bleaching System on Color, Hardness and Microstructure of Dental Enamel.

This study aimed to evaluate two hydrogen peroxide (HP)-based at-home bleaching systems in order to analyze whether nano-hydroxyapatite (nHA) addition may represent a reliable and safe solution for tooth whitening without altering dental microstructure and hardness. Human third molars (N = 15) were treated with two bleaching agents, one containing 6%HP (6HP) and the other 6% HP nHA-enriched (6HP-nHA) with average particle diameter ranging from 5-20 nm. Their effects on enamel were assessed using a spectrophotometer, Vickers microhardness (VMH) test and Scanning Electron Microscopy (SEM), comparing the treated groups with the non-treated control group (CTR). Color analysis revealed improvement in whiteness in both groups compared to CTR. VMH test results showed no differences among the groups. SEM analysis highlighted no evident changes in the enamel microstructure of tested groups compared to CTR. At high magnification, in 6HP group, a slight increase in irregularities of enamel surface morphology was observed, while 6HP-nHA group displayed removal of the aprismatic layer but preservation of the intact prismatic structure. These results suggest that the 6HP-nHA agent may be recommended to provide reliable whitening treatment, without damaging the enamel micromorphology and hardness.

Minimally invasive esthetic management of dental fluorosis: a case report.

Dental fluorosis is a dental condition caused by excessive intake of fluoride during enamel formation, which can lead to color abnormalities or defects on the tooth surface. The resultant abnormal appearance ranges in severity from mildly white and opaque to dark brown, which substantially affects patients' esthetic characteristics and self-confidence. Treatment methods include tooth whitening or restoration. This clinical report describes the use of a minimally invasive esthetic technique in a 22-year-old woman with moderate dental fluorosis. The treatment plan included enamel microabrasion, at-home bleaching for 2 weeks, and subsequent resin infiltration for each tooth under a rubber dam. After 2 years of follow-up, evaluation of the patient's esthetic appearance revealed that teeth affected by dental fluorosis could be successfully treated with a minimally invasive technique involving microabrasion, at-home bleaching, and resin infiltration.

Initial and pulp chamber concentration of hydrogen peroxide using different bleaching products / Concentração de peróxido de hidrogênio na câmara pulpar utilizando diferentes produtos clareadores

Objective: This study's aim was to quantify the hydrogen peroxide (HP) penetration into the pulp chamber of teeth submitted to different protocols of bleaching. Material and Methods: Ninety premolars were randomly divided into nine groups according to the bleaching agent protocol (n = 10): control (no bleaching), carbamide peroxide 10% [10% CP], carbamide peroxide 16% [16% CP], carbamide peroxide 22% [22% CP], hydrogen peroxide 4% [4% HP], hydrogen peroxide 6% [6% HP], hydrogen peroxide 7.5% [7.5% HP], hydrogen peroxide 10% [10% HP] and hydrogen peroxide 35% [35% HP]. The penetration of HP was measured via spectrophotometric analysis of the acetate buffer solution from the pulp chamber. The absorbance of the resulting solution was determined in a spectrophotometer and converted into equivalent concentration of HP (µg/ mL). To analyze the concentration of HP, the titration of bleaching agents with potassium permanganate was used. Data were subjected to ANOVA and Tukey's test for pairwise comparison (α = 0.05). Results: Higher concentration of HP in the pulp chamber was found in the HP 35% group (p < 0.0001). No significant difference between at-home protocols were observed (p = 0.64). Titration values showed that the concentration of the products was similar to that claimed by the manufacturer. Conclusion: It follows that the amount of HP that reaches the pulp chamber is not proportional to the concentration of whitening gels, but depends on the application time recommended by the manufacturers (AU)

Objetivo: o objetivo deste estudo foi quantificar a penetração do peróxido de hidrogênio (PH) na câmara pulpar dos dentes submetidos a diferentes protocolos de clareamento. Material e Métodos: Noventa pré-molares foram divididos aleatoriamente em nove grupos, de acordo com o protocolo do agente clareador (n = 10): controle (sem clareamento), peróxido de carbamida 10% [PC 10%], peróxido de carbamida 16% [PC 16%], peróxido de carbamida 22% [PC 22%], peróxido de hidrogênio 4% [PH 4%], peróxido de hidrogênio 6% [PH 6%], peróxido de hidrogênio 7,5% [PH 7,5%], peróxido de hidrogênio 10% [PH 10%] e peróxido de hidrogênio 35% [PH 35%]. A penetração de PH foi medida por análise espectrofotométrica da solução de tampão de acetato da câmara pulpar. A absorvância da solução resultante foi determinada em um espectrofotômetro e convertida em concentração equivalente de PH (µg / mL). Para analisar a concentração de PH, foi utilizada a titulação de agentes clareadores com permanganato de potássio. Os dados foram submetidos à ANOVA e teste de Tukey para comparação pareada (α = 0,05). Resultados: Foi encontrada maior concentração de PH na câmara pulpar no grupo PH 35% (p < 0,0001). Não foi observada diferença significativa entre os protocolos domiciliares (p = 0,64). Os valores de titulação mostraram que a concentração dos produtos era semelhante à reivindicada pelo fabricante. Conclusão: Conclui-se que a quantidade de PH que atinge a câmara pulpar não é proporcional à concentração de géis clareadores, porém depende do tempo de aplicação recomendado pelos fabricantes.(AU)

Effects of at-home bleaching and resin infiltration treatments on the aesthetic and psychological status of patients with dental fluorosis: A prospective study.

OBJECTIVE: This study aims to evaluate the effect of the combination approach of at-home bleaching (HB) and resin infiltration (RI) techniques on different severity degrees of dental fluorosis (DF) and further analyze the psychological changes caused by HB and RI in patients. METHOD: Twenty-two patients (4 males, 18 females, 27.8 ±â€¯1.6 yrs) with 186 fluorotic teeth were included in this study and classified into mild (N = 56), moderate (N = 100) and severe (N = 30) DF groups according to the Dean's index. The treatment effects on patients with DF were assessed by questionnaires including the changes in patients' subjective evaluation of their teeth and psychological status before and after treatments. Standardized digital photographs were taken at each time point of the treatment process, including baseline (T1), after bleaching (T2), immediately after RI treatment (T3) and more than six months after RI treatment (T4). The color alterations (ΔE) between the fluorotic (F2) and the surrounding relatively sound areas (F1) were analyzed. RESULTS: Bad tooth appearance caused 13.64% of patients often depressed, frustrated, or disappointed, whereas 72.72% occasionally had these feelings. After treatment, the satisfaction of DF patients regarding tooth appearance increased from 0% (satisfied) to 58.82% (satisfied) and 23.53% (very satisfied). Moreover, these treatments improved all patients' confidence in smiling, laughing and showing their teeth. The percentage of fluorotic teeth with ΔE values more than 3.0 and 3.7 units decreased gradually from T1 stage to T3 stage in mild and moderate DF groups (p < 0.05), whereas the ΔE value in T3 stage was significantly lower than that of T2 stage in severe DF group (p < 0.05). In T4 stage, no significant difference was observed in the ΔE values between T4 and T3 stages (p > 0.05). CONCLUSION: This study shows the obvious positive aesthetic effect of HB and RI treatment on different severity degrees of DF and the great improvements in psychological discomforts. CLINICAL SIGNIFICANCE: The combination treatment of RI and low concentration HB gel improves the aesthetics of DF and may have a stable effect after 6-months follow-up, suggesting that this approach is a valuable clinical choice for dentists to treat DF.

Does the use of reservoirs have any impact on the efficacy of at-home bleaching? a systematic review

Abstract To answer the following focused question through a systematic review: "Are the risk and intensity of tooth sensitivity (TS) and bleaching efficacy different between adult patients who undergo at-home bleaching using trays with reservoirs and those who use trays without reservoirs?". A comprehensive search was performed in the MEDLINE via PubMed, Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature database, Brazilian Library in Dentistry, Cochrane Library, and grey literature without restrictions. Abstracts from conferences; unpublished and ongoing trial registries, dissertations and theses (ProQuest Dissertations and Periódicos Capes Theses databases) were searched. Only randomized clinical trials (RCTs) were included. We used the Risk of Bias tool (RoB) from the Cochrane Collaboration for quality assessment. After the removal of duplicates, title and abstract screening and full-text examination, nine RCTs remained for qualitative analyses. The great majority of the studies did not report the method of randomization, allocation concealment, and examiner blinding during color assessment. From the nine studies, eight were at unclear risk of bias. In regard to color change, four studies reported no change and two reported improved color change with reservoirs. Only four studies recorded tooth sensitivity and they reported no significant differences. Only one study reported greater gingival irritation with reservoirs. Lack of data reporting prevented us from running a meta-analysis. Further well-designed RCT should be conducted to answer this research question. So far there is not evidence to support that reservoirs in bleaching trays improve color change. PROSPERO - CRD42016037628

Resumo Para responder a seguinte questão de pesquisa através de uma revisão sistemática: "O risco e a intensidade de sensibilidade dentária (SD) e eficácia de clareamento são diferentes entre pacientes adultos que realizam clareamento caseiro usando moldeiras com reservatórios e aqueles que usam moldeiras sem reservatórios?". Uma pesquisa abrangente foi realizada no MEDLINE via PubMed, Scopus, Web of Science, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Biblioteca Cochrane e literatura cinzenta, sem restrições. Os resumos da conferência anual da Associação Internacional para Pesquisa Dental além de estudos registrados ou em andamento também foram pesquisados. Dissertações e Teses foram pesquisados utilizando o Capes Journal Dissertações e Teses ProQuest. Apenas ensaios clínicos randomizados (ECR) foram incluídos. Usamos a ferramenta Risk of Bias (RoB) da Cochrane para avaliação de qualidade. Após a remoção de duplicatas, triagem de título e resumo e exame de texto completo, nove ECRs permaneceram para análises qualitativas. A grande maioria dos estudos não relatou o método de randomização, ocultação de alocação e cegamento do examinador durante a avaliação de cores. Dos nove estudos, oito estavam sob risco claro de viés. Em relação à mudança de cor, quatro estudos não relataram nenhuma mudança e dois relataram melhora na mudança de cor com reservatórios. Apenas quatro estudos registraram a sensibilidade dentária e não relataram diferenças significativas. Apenas um estudo relatou maior irritação gengival com reservatórios. A falta de relatórios de dados nos impediu de executar uma meta-análise. Outros ECR bem desenhados devem ser conduzidos para responder a esta questão de pesquisa. Até agora não há evidências que sustentem que reservatórios em moldeiras de clareamento melhorem a mudança de cor. PROSPERO - CRD42016037628

Evaluation of the genotoxic potential of different delivery methods of at-home bleaching gels: a single-blind, randomized clinical trial.

OBJECTIVE: This single-blind, parallel, randomized clinical trial evaluated the genotoxic potential and effectiveness of 10% hydrogen peroxide (HP) in patients submitted to at-home bleaching. MATERIALS AND METHODS: Sixty young volunteers with maxillary incisors equal to or darker than M1.5 were included in the study. Patients were submitted to bleaching for 14 days (30 min/day) with one of the three 10% HP treatments: the bleaching agent was delivered in a bleaching tray (White Class, FGM), whitening strips (White Strips, Oral-b), or in prefilled disposable trays (Opalescence Go, Ultradent). The color change was evaluated with the Vita Bleachedguide, and the micronucleus test of exfoliative oral mucosa was carried out, starting from a count of 1000 cells, at the baseline, immediately after and 30 days after the end of the treatment. The micronucleus data were evaluated with the Kruskal-Wallis and Wilcoxon tests and color change with the two-way ANOVA test and the Tukey test (α = 0.05). RESULTS: Significant whitening was observed for all groups after 14 days (p = 0.001) and was maintained after 30 days, with no difference between groups (p = 0.42). The micronucleus count did not indicate genotoxic potential in any of the groups studied (p = 0.32), irrespective of the time intervals (p = 0.62). CONCLUSION: No genotoxic effects of 10% HP were observed in patients submitted to at-home bleaching systems (30 min/day for 14 days), even 30 days after the end of treatment. CLINICAL SIGNIFICANCE: It is safe to use different systems to deliver 10% HP during at-home bleaching according to the manufacturers' recommendations, with no risk of genotoxic effects applied.

Influence of treatment duration on the efficacy of at-home bleaching with daytime application: a randomized clinical trial.

OBJECTIVE: The aim of this study is to determine whether prolonging the daytime at-home bleaching treatment by 1 week increases the bleaching effect without causing more side effects. MATERIALS AND METHODS: Fifty participants were randomly divided into two groups, (A) with a 14-day treatment and (B) with a 21-day treatment. A gel with 10% carbamide peroxide was applied for 2 h a day in custom trays. Color measurement was performed using a dental spectrophotometer on the right maxillary central incisor and the canine at baseline, at the end of treatment, and 1 and 6 months afterwards. Daily, participants recorded their tooth sensitivity and gingival irritation. RESULTS: At the end of the treatment, the ΔE00 of group B (5.77 ± 2.15) was significantly higher than the ΔE00 of group A (4.74 ± 1.94) (p = 0.005 (95% CI: - 2.13 to - 0.39)). After 6 months, tooth color was more stable in group B. The ΔSGU values between the different appointment times were higher in the 3-week group. Participants from group B reported more side effects, but statistically, there were no differences compared with group A (p = 0.225 for tooth sensitivity and p = 0.758 for gingival irritation). CONCLUSIONS: Daytime application of at-home bleaching for 3 weeks achieves greater bleaching results than for 2 weeks, immediately after treatment and 1 and 6 months afterwards. However, slightly more side effects could occur. CLINICAL RELEVANCE: When daytime application of at-home bleaching is required, the treatment duration should be prolonged from 2 to 3 weeks to achieve greater and more stable results.

Aesthetic effect of minimally invasive therapy on stained dental fluorosis / 中华地方病学杂志

Objective To observe the aesthetic effect of low concentration of at-home bleaching combined with microabrasion and resin infiltration on stained dental fluorosis.Methods Twenty-three patients with stained dental fluorosis were selected from June 2017 to June 2018 in Stomatological Hospital of Tianjin Medical University.All patients were treated with minimally invasive whitening technology of microabrasion,10％ low concentration of at-home bleaching and resin infiltration.The aesthetic treatment effect was observed before and after treatment by VITA aesthetic shade guide matching.Stained spots were chosen and colorimetric assay was performed using CMYK shade guide before treatment.According to the color of the splash,the light and shade were divided into light grade,medium grade and heavy grade.The CMYK data of the selected spot and complete decolorization ratio (stain decolorization rate) were recorded 1 week and half a year after treatment.Meanwhile,tooth sensitivity was recorded using visual analogue scale (VAS).Results The shades of 92 teeth of 23 dental fluorosis patients were increased more than 5 degrees after a series of whitening treatment,1 tooth was 2-4 degrees,and the total effective rate was 100.00％ (92/92).Decolorization rates of light grade,medium grade and heavy grade were 100.00％ (100/100),100.00％ (120/120) and 97.78％ (88/90),respectively,1 week after treatment.Half a year after treatment,bleaching decolorization rate had no significant difference compared with that of 1 week after treatment (P ＞ 0.05).Tooth sensitivity was 91.30％ (21/23).Almost all patients had mild and moderate teeth sensitivity during treatment.The symptoms of tooth sensitivity were disappeared after the treatment.Conclusions The whitening technology of microabrasion,10％ low concentration of at-home bleaching and resin infiltration has a significant decolorization whitening effect,and has a certain degree of stability and no sensitive teeth after treatment.It is worthy of clinical application.

Comparison of efficacy of tray-delivered carbamide and hydrogen peroxide for at-home bleaching: a systematic review and meta-analysis.

OBJECTIVES: The aim of the study was to compare the color change produced by tray-delivered carbamide peroxide [CP] versus hydrogen peroxide products [HP] for at-home bleaching through a systematic review and meta-analysis. MATERIALS AND METHODS: MEDLINE via PubMeb, Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature database (LILACS), Brazilian Library in Dentistry (BBO), and Cochrane Library and Grey literature were searched without restrictions. The abstracts of the International Association for Dental Research (IADR) and unpublished and ongoing trial registries were also searched. Dissertations and theses were explored using the ProQuest Dissertations and Periodicos Capes Theses databases. We included randomized clinical trials that compared tray-delivered CP versus HP for at-home dental bleaching. The color change in shade guide units (SGU) and ΔE were the primary outcomes, and tooth sensitivity and gingival irritation were the secondary outcomes. The risk of bias tool of the Cochrane Collaboration was used for quality assessment. DATA: After duplicate removal, 1379 articles were identified. However, only eight studies were considered to be at "low" risk of bias in the key domains of the risk bias tool and they were included in the analysis. For ΔE, the standardized mean difference was -0.45 (95 % CI -0.69 to -0.21), which favored tray-delivered CP products (p < 0.001). The color change in ΔSGU (p = 0.70), tooth sensitivity (p = 0.83), and gingival irritation (p = 0.62) were not significantly different between groups. CONCLUSIONS: Tray-delivered CP gels showed a slightly better whitening efficacy than HP-based products in terms of ΔE, but they were similar in terms of ΔSGU. Both whitening systems demonstrated equal level of gingival irritation and tooth sensitivity. CLINICAL SIGNIFICANCE: Tray-delivered CP gels have a slightly better whitening efficacy than HP-based products in terms of ΔE. This should be interpreted with caution as the data of ΔSGU did not show statistical difference between the products.

One-year follow-up of at-home bleaching in smokers before and after dental prophylaxis.

OBJECTIVE: This clinical study evaluated the color longevity after one-year of at-home bleaching with 10% carbamide peroxide (CP) in smokers and nonsmokers. METHODS: Sixty patients, 30 smokers and 30 non-smokers were subjected to bleaching with 10% CP during three hours daily for three weeks. The color was measured at baseline and one week, one month and one year after the completion of dental bleaching using the spectrophotometer Vita Easyshade (ΔE*), shade guide Vita classical organized by value and Vita Bleachedguide 3D-MASTER (ΔSGU). In the one-year recall, the color was assessed before and after dental prophylaxis with Robinson brush and prophylaxis paste. Data from color evaluation were analyzed by two-way repeated measures ANOVA and Tukey's test for the contrast of means (α=0.05). RESULTS: Twenty-seven smokers and 28 non-smokers attended the one-year recall. For both study groups, only the main factor assessment time was statistically significant for ΔSGU (Vita classical) and ΔE* (p<0.001). Effective whitening was observed for both groups at baseline, which was stable at one-month and one year after dental prophylaxis. A slight darkening was observed after one year when the color was measured without prophylaxis. For the Vita Bleachedguide 3D-MASTER, color rebound was observed irrespectively of dental prophylaxis. CONCLUSION: The bleaching with 10% CP remained stable in both groups as long as extrinsic stains from diet and cigarette smoke were removed by professional dental prophylaxis. CLINICAL TRIALS REGISTRY: NCT02017873. CLINICAL RELEVANCE: The results of this study indicate that the bleaching is effective in smokers even after one-year, but dental prophylaxis may be necessary to remove extrinsic stains caused by diet and smoking.

Evaluation of the efficacy of potassium nitrate and sodium fluoride as desensitizing agents during tooth bleaching treatment­A systematic review and meta-analysis.

OBJECTIVES: This meta-analysis was performed to evaluate the efficacy of potassium nitrate and sodium fluoride as desensitizing agents during tooth bleaching treatment. DATA, SOURCES AND STUDY SELECTION: An electronic systematic literature search was conducted in Cochrane Center Register of Controlled Trials, MEDLINE (PubMed) and EmBase in April, 2014 in English and without time restrictions. Study information extraction and methodological quality assessments were accomplished by two reviewers independently. Methodological quality was assessed by using the "Criteria for judging risk of bias in the 'Risk of bias' assessment tool". Dichotomous data was summarized by odds ratio (OR) with 95% confidence interval (CI) and continuous data was summarized by mean difference (MD) or standardised mean difference (SMD) with 95% confidence interval (CI). Statistical analyses were carried out by using Review Manager 5.2. For evaluation of percent of patients experiencing tooth sensitivity (POTS), the pooled OR of desensitizers vs. placebo was 0.45 (95% CI: 0.28-0.73, P=0.29). The pooled SMD of desensitizers vs. placebo was -0.47 (95% CI: -0.77 to -0.18, P=0.13) in evaluation of level of tooth sensitivity (LOTS). The results of shade evaluation remained inconsistent by evaluating subjective shade guide unit difference (ΔSGU or SGU) and objective colour difference (ΔE). CONCLUSIONS: This meta-analysis was performed to evaluate the efficacy of desensitizing agents, potassium nitrate and sodium fluoride, for tooth bleaching treatments. Potassium nitrate and sodium fluoride reduce tooth sensitivity while no consistent conclusion of tooth colour change was found. CLINICAL SIGNIFICANCE: Tooth sensitivity is a typical side effect associated with tooth bleaching procedures. Potassium nitrate and sodium fluoride are used widely to treat tooth sensitivity. This meta-analysis was performed to evaluate the efficacy of potassium nitrate and sodium fluoride as desensitizing agents during tooth bleaching treatment.

An In vitro Study on Post Bleaching Pigmentation Susceptibility of Teeth and Scanning Electron Microscopy Analysis.

BACKGROUND: To determine the susceptibility of teeth for repigmentation after bleaching. MATERIALS AND METHODS: Forty premolars were assigned to three groups (n = 12). Group 1 was bleached using 30% w/v hydrogen peroxide 15 min 3 times a day every other day for 4 days. In Group 2 was bleached using 16% carbamide peroxide (Polanight), 90 min a day for 15 days. 2 days later, the shades of the bleached teeth were recorded. Remaining 4 teeth were bleached according to Group 1 and 2 and were subjected to atomic force microscopy, scanning electron microscopy analysis. RESULTS: Specimens of athome bleaching were lighter than the specimens of inoffice bleaching. CONCLUSION: The susceptibility of enamel to pigmentation can be increased after bleaching, and pigmentation is greater if bleaching is performed with H2O2. The percentage change (lighter) was more for athome bleaching specimens as compared to inoffice bleaching specimens.

The degree of color change, rebound effect and sensitivity of bleached teeth associated with at-home and power bleaching techniques: A randomized clinical trial.

AIM: The purpose of the present randomized clinical trial was to evaluate the color change, rebound effect and sensitivity of at-home bleaching with 15% carbamide peroxide and power bleaching using 38% hydrogen peroxide. MATERIALS AND METHODS: For bleaching techniques, 20 subjects were randomized in a split mouth design (at-home and power bleaching): In maxillary and mandibular anterior teeth (n = 20). Color was recorded before bleaching, immediately after bleaching, at 2 weeks, 1, 3 and 6 month intervals. Tooth sensitivity was recorded using the visual analog scale. The Mann-Whitney test was used to compare both groups regarding bleaching effectiveness (ΔE1), rebound effect (ΔE2) and color difference between the rebounded tooth color and unbleached teeth (ΔE3) while the Wilcoxon compared ΔE within each group. Distribution of sensitivity was evaluated using the Chi-square test (α =0.05). RESULTS: There was no significant difference between groups regarding ΔE1 and ΔE3 (P > 0.05). Even though, ΔE2 showed no significant difference between groups after bleaching as well as at 2 week, 1 month and 3 month follow-up periods (P > 0.05). Although, significant difference was found in ΔE2 (P < 0.05 Mann-Whitney) between two methods after 6 months and a high degree of rebound effect was obtained with power bleaching. Within each group, there was no significant difference between ΔE1 and ΔE3 (P < 0.05 Wilcoxon). The distribution of sensitivity was identical with both techniques (P > 0.05). CONCLUSION: Bleaching techniques resulted in identical tooth whitening and post-operative sensitivity using both techniques, but faster color regression was found with power bleaching even though color regression to the baseline of the teeth in both groups was the same after 6 months.