Teeth whitening with 6% hydrogen peroxide and its impact on quality of life: 2 years of follow-up

Effects of online marketplace-sourced over-the-counter tooth whitening products on the colour, microhardness, and surface topography of enamel: an in vitro study

OBJECTIVES

This study compared the whitening effect, microhardness, and enamel surface alterations of over-the-counter (OTC) tooth bleaching products with those of a dentist-prescribed at-home bleaching agent.

MATERIALS AND METHODS

The products available on a popular online marketplace were comprehensively searched and then rated using a specific formula. The effects of the lowest-rated OTC agent (LRA) and the highest-rated OTC agent (HRA) were compared with those of a dentist-prescribed bleaching agent (DPA) on the enamel of extracted human teeth. The bleaching efficacy, post-bleaching microhardness changes, and morphological alterations were assessed by spectrophotometric analysis, Vickers hardness testing, and scanning electron microscopy (SEM) respectively. Statistical analyses included one-way ANOVA and post hoc tests, maintaining a significance level of P < 0.05.

RESULTS

The search of the online marketplace revealed 15 products. The LRA (Teeth Whitening Serum Gel, GEN, China) and the HRA (Bright White-Lovely Smile Premium Teeth Whitening strips, Ray of Smile, USA) were identified on the basis of their ranking. DPA resulted in significantly better tooth whitening than did LRA. The enamel microhardness was lower in the LRA treatment group (14.2%) than in the control and HRA treatment groups (8.84% and 7.26%, respectively). LRA also caused severe topographical alterations to the enamel.

CONCLUSION

Compared with the poorly rated product, the dentist-prescribed tooth bleaching product resulted in greater colour improvement, less microhardness reduction, and surface changes. The highest-rated product was comparable with the dentist-prescribed agent in this study.

Clinical comparison of whitening efficacy and tooth sensitivity of different concentrations of hydrogen peroxide photoactivated with violet or blue LEDs

This study evaluated the photoactivation of hydrogen peroxide gels at different concentrations using blue or violet LED in terms of whitening efficacy and tooth sensitivity. Forty patients were randomly divided into 4 groups: HP6V (violet LED and 6% hydrogen peroxide), HP6B (blue LED and 6% hydrogen peroxide), HP35V (violet LED and 35% hydrogen peroxide), and HP35B (blue LED and 35% hydrogen peroxide). The L*, a* and b* values were measured before, 1 week and 3 months after treatment, and the ΔE and ΔWID values were calculated. Tooth sensitivity was measured using a visual analogue scale (VAS) before, immediately after, and 24 h after bleaching. The ΔE, ΔWID and bleaching sensitivity values were subjected to the ANOVA test and Bonferroni post-test. HP35V and HP35B showed higher whitening efficacy than HP6VL, while HP6V did not show statistical differences compared to the other groups. Regarding bleaching-related sensitivity, the HP6V and HP6B groups presented the lowest values when compared to HP35V and HP35B. HP6V showed whitening efficacy comparable to HP35V and HP35B but with reduced tooth sensitivity. TRIAL REGISTRATION NUMBER: NCT06165458; registration date: 12/09/2023.

In-office Bleaching Activated With Violet LED: Effect on Pulpal and Tooth Temperature and Pulp Viability

OBJECTIVES

This study evaluated the influence of hydrogen peroxide (HP) with or without titanium dioxide nanotubes (TiO2) associated with violet LED (VL) regarding: a) the temperature change in the pulp chamber and facial surface; b) the decomposition of HP; and c) the cytotoxicity of the gels on pulp cells.

METHODS AND MATERIALS

The experimental groups were: HP35 (35% HP/Whiteness HP, FGM); HP35+VL; HP35T (HP35+TiO2); HP35T+VL; HP7 (7.5% HP/White Class 7.5%, FGM); HP7+VL; HP7T (HP7+TiO2); and HP7T+VL. TiO2 was incorporated into the bleaching gels at 1%. Eighty bovine incisors were evaluated to determine temperature change in 8 experimental groups (n=10/group). A k-type thermocouple was used to evaluate the temperatures of the facial surface and in the pulp chamber, achieved by enabling endodontic access to the palatal surface, throughout the 30-minute session. HP decomposition (n=3) of gels was evaluated by using an automatic potentiometric titrator at the initial and 30-minute time points. Trans-enamel and trans-dentinal cell viability were assessed with a pulp chamber device as well as enamel and dentin discs (n=6), and the treatment extracts (culture medium + diffused components) were collected and applied to MDPC-23 odontoblast cells to evaluate cell viability according to the MTT test.

RESULTS

A temperature increase in the pulp chamber was observed in the presence of VL at 30 minutes (p<0.05) (Mann-Whitney test). Also at 30 minutes, HP35 showed greater decomposition in the presence of VL rather than in its absence (p<0.05) (mixed linear models and the Tukey-Kramer test). HP7 provided greater cell viability than the groups treated with HP35 (p<0.05) (generalized linear models test). Cell viability was significantly lower for HP7 in the presence of VL (p<0.05).

CONCLUSION

Pulpal temperature increased with VL (maximum of 1.9°C), but did not exceed the critical limit to cause pulp damage. Less concentrated HP resulted in higher cell viability, even when associated with VL.

In-office dental bleaching in adolescents using 6% hydrogen peroxide with and without gingival barrier: a randomized double-blind clinical trial

BACKGROUND

At low concentrations used for in-office bleaching gels, such as 6% HP, gingival barrier continues to be performed. If we take into account that, in the at-home bleaching technique, no barrier is indicated, it seems that the use of a gingival barrier fails to make much sense when bleaching gel in low concentration is used for in-office bleaching.

OBJECTIVE

This double-blind, split-mouth, randomized clinical trial evaluated the gingival irritation (GI) of in-office bleaching using 6% hydrogen peroxide (HP) with and without a gingival barrier in adolescents, as well as color change and the impact of oral condition on quality of life.

METHODOLOGY

Overall, 60 participants were randomized into which side would or would not receive the gingival barrier. In-office bleaching was performed for 50 minutes with 6% HP in three sessions. The absolute risk and intensity of GI were assessed with a visual analogue scale. Color change was assessed using a digital spectrophotometer and color guides. The impact of oral condition on quality of life was assessed using the Brazilian version of the Oral Health Impact Profile (α=0.05).

RESULTS

The proportion of patients who presented GI for the "with barrier" group was 31.6% and for the "without barrier" group, 30% (p=1.0). There is an equivalence for the evaluated groups regarding GI intensity (p<0.01). Color change was detected with no statistical differences (p>0.29). There was a significant impact of oral condition on quality of life after bleaching (p<0.001).

CONCLUSIONS

The use or not of the gingival barrier for in-office bleaching with 6% HP was equivalent for GI, as well as for bleaching efficacy, with improvement in the impact of oral condition on quality of life.

Influence of blue and violet LED and infrared laser on the temperature of bleaching protocols in different concentrations of hydrogen peroxide

BACKGROUND

The photo-acceleration of bleaching gels by lights has been extensively researched. However, the induced temperature increase during this process needs to be further evaluated to prevent damage to the dental pulp. Therefore, the objective of this study was to evaluate the surface and intrapulpal temperature kinetics of different concentrations of hydrogen peroxide (HP) gels photo-accelerated by blue or violet light and infrared laser.

METHODS

The whitening gels at concentrations of HP35, HP15, and HP6 % were irradiated with blue and violet LED/laser on the surface of a human canine tooth. The surface temperature variation (∆Ts) was evaluated using a pH meter, while the intrapulpal temperature variation (∆Ti) was assessed using a digital thermometer at intervals of 1, 15, and 30 min. Statistical analysis was conducted using a Two-way repeated measures ANOVA test, and Bonferroni post-test was applied at a significance level of 5 %.

RESULTS

All violet LED photo-accelerated groups showed a higher increase in ∆Ts compared to the blue LED/laser groups. However, there were no significant differences between the groups for ∆Ti.

CONCLUSION

Although the photo-acceleration of HP35 and HP15 % gels with violet LED/laser has a greater increase in surface temperature compared to HP6 % gel, the different light systems do not significantly increase the intrapulpal temperature.

In-office dental bleaching in adolescents using 6% hydrogen peroxide with different application tips: randomized clinical trial

OBJECTIVE

Despite the availability of in-office bleaching gels with a 6% concentration of hydrogen peroxide (HP), these gels have not been evaluated in younger patients. They are commercially available with a tip, associated or not with a brush, where the tip with a brush spreads the gel over the entire surface to have a smaller thickness (thin layer) since the manufacturers indicate the application of a thin layer of gel. This randomized, split-mouth, double-blind clinical trial evaluated the efficacy of in-office bleaching with 6% HP in adolescents using different application tips, as well tooth sensitivity (TS) and aesthetic self-perception.

METHODOLOGY

Sixty participants were randomized for 6% HP self-mixing bleaching gel tip design: without brush and with brush. In-office bleaching was performed in 3 sessions of 50 minutes. Color change was evaluated using a digital spectrophotometer (ΔE ab , ΔE 00 , and ΔWI D ) and color guide (ΔSGU), the absolute risk and intensity of TS with a visual analogue scale and aesthetic self-perception with the oral aesthetic scale (a=0.05).

RESULTS

The groups achieved similar bleaching regardless of the application tip (p>0.05). However, only for ΔWI D , a significant mean difference (MD) was observed in the third week (MD 2.3; 95% CI 1.2 to 3.3; p < 0.001) and at one month (MD 1.6; 95% CI 0.6 to 2.6; p < 0.03) favoring the tip without brush. Regarding TS, 45% in the tip-without-brush group and 33% in the tip-with-brush group reported TS (odds ratio 0.61; 95% CI 0.29 to 1.28; p<0.02), with low TS intensity (MD 0.05; 95% CI -0.06 to 0.17; p>0.36). All patients reported improved aesthetic self-perception after bleaching (MD -1.3; 95% -1.8 to -0.9; p<0.001).

CONCLUSIONS

Regardless of the tip used bleaching with 6% HP achieved a bleaching efficacy and improved the aesthetic self-perception. However, a lower risk of TS for application using the tip with brush was observed.

Surface and intra-pulpal temperature variation during tooth whitening photoactivated with LED/laser

This study evaluated the variation of surface and intra-pulpal temperature, during bleaching protocol, using LED/laser. The 35% (HP35), 15% (HP15) and 6% (HP6) gels were used associated with LED/laser applied every 1 min for 30 min in a human canine. The evaluation of surface temperature variation (∆Ts) was performed using a pHmeter and the intra-pulpal temperature variation (∆Ti) was performed using a digital thermometer, at times of 1-, 5-, 10- 15- and 30-min. Statistical analysis was performed using the two-way repeated measures ANOVA test and Bonferroni post-hoc test was used at a significance level of 5%. HP35 and HP15 showed greater temperature variation than HP6 up to 10 min of surface evaluation, showing no differences between them. In the intra-pulpal evaluation, no group showed differences throughout the procedure.

Microstructural effect of different concentrations of hydrogen peroxide photoactivated with LED/laser

BACKGROUND

The use of different concentrations of hydrogen peroxide (HP) photoactivated with LED/laser sources is recurrent; however, their influence on tooth structure is not yet fully elucidated. This study aimed to evaluate the pH, microhardness and surface roughness of different bleaching protocols photoactivated with LED/laser.

METHODS

Forty bovine incisors were sectioned (7×7×2mm) and randomized into four groups for analysis of pH (n=5), microhardness and roughness (n=10): HP35, HP6_L, HP15_L, HP35_L. The pH analysis was performed in the initial and final minute of the bleaching protocol. Microhardness and roughness were evaluated before and 7 days after the last bleaching session. Results were obtained from two-way ANOVA for repeated measures and Bonferroni post-test at a significance level of 5%.

RESULTS

HP6_L showed higher pH and greater stability between the initial and final evaluations, while the other groups showed similar pH with reduced values in the intragroup evaluation. No differences between groups in microhardness and roughness evaluations were observed.

CONCLUSIONS

Although HP6_L showed higher alkalinity and pH stability, none of the protocols reduced the microhardness and surface roughness of bovine enamel.

Improved esthetic efficacy and reduced cytotoxicity are achieved with a violet LED irradiation of manganese oxide-enriched bleaching gels

Gels with high concentrations of hydrogen peroxide (H2O2) have been associated with cytotoxicity and consequent post-bleaching tooth sensitivity. This study assessed the bleaching efficacy (BE) and cytotoxicity (CT) of bleaching gels with low concentrations of H2O2 containing manganese oxide (MnO2) and photocatalyzed with violet LED (LEDv). The following groups were established: G1: no treatment (negative control, NC); G2: 35% H2O2 (positive control, PC); G3: LEDv; G4: 10% H2O2; G5: 6% H2O2; G6: 10% H2O2 + MnO2 + LEDv; G7: 6% H2O2 + MnO2 + LEDv. To analyze BE, standardized enamel/dentin discs (E/DDs) were subjected to the bleaching procedures for 45 min (1 session). The color change was determined before and after performing the bleaching protocols (ΔE00; ΔWI). To analyze CT, the E/DDs were adapted to artificial pulp chambers, and the extracts (culture medium + diffused gel components) were applied to cultured odontoblast-like MDPC-23 cells. Then, the cells were assessed concerning their viability (VB), oxidative stress (OxS), and Live/Dead. The amount of H2O2 diffused was also determined (ANOVA/Tukey; p < 0.05). Cell viability decreased in all bleached groups compared to G1 (NC; p < 0.05). The cells in G6 and G7 presented higher viability than in G2, G4, and G5 (p < 0.05). The BE in G7 was similar to G2 (PC; p < 0.05). The lowest OxS and H2O2 diffusion values were found in G6 and G7, compared to the other bleached groups (G2, G4, and G5; p < 0.05). The 6% H2O2 bleaching gel (G7) submitted to both methods of catalysis (MnO2 + LEDv) caused only a mild cytotoxicity and maintained the excellent esthetic outcome promoted by in-office conventional tooth bleaching.

Violet LED associated with high concentration hydrogen peroxide: Effects on bleaching efficacy, pH, and temperature

BACKGROUND

This study aimed to evaluate the bleaching efficacy, pH, and temperature of 35% hydrogen peroxide (HP) gel used alone or associated with violet LED.

METHODS

Sixty bovine crowns were sectioned (5 × 5 × 2mm). After staining with black tea, the specimens were randomized into four groups (n = 10) according to the bleaching protocol: HP35R: 3 × 15 min 35% HP; HP35: 1 × 45 min 35% HP; HP35VR: 3 × 8min 35% HP + Violet LED; HP35V: 1 × 24 min + Violet LED. Two bleaching sessions were performed for all the groups. Color change was evaluated before, 24h after each session, 7 days and 15 days after the last session. The variables ∆E₀₀ [CIEDE2000] and W_ID were used for color analysis. The pH variation (initial and final) and the temperature of the gel were recorded (n = 5). ANOVA two-way for repeated measures and Bonferroni post-test was used at a significance level of 5%.

RESULTS

HP35VR and HP35V the most noticeable color change(p < 0.05). The final values of pH were lower than the initial ones, but with no difference between the groups (p > 0.05). Groups HP35VR and HP35V showed an increase in temperature in relation to HP35R (p < 0.05).

CONCLUSIONS

Violet LED improved the bleaching efficacy of 35% HP in a time-saving manner without negatively affecting the pH and temperature of 35% HP. The renewal of HP did not influence the outcomes.

Manganese oxide increases bleaching efficacy and reduces the cytotoxicity of a 10% hydrogen peroxide bleaching gel

OBJECTIVE

The study aims to assess the effects of a 10% H₂O₂ bleaching gel with different MnO₂ concentrations on the bleaching efficacy (BE), degradation kinetics (DK) of H₂O₂, and trans-amelodentinal cytotoxicity (TC).

MATERIALS AND METHODS

Standardized bovine enamel/dentin disks (n = 96) were placed in artificial pulp chambers, and the bleaching gels were applied for 45 min. Thus, the following groups were established: (G1) no treatment (negative control/NC); (G2) 35% H₂O₂ (positive control/PC); (G3) 10% H₂O₂; (G4) 10% H₂O₂ + 2 mg/mL MnO₂; (G5) 10% H₂O₂ + 6 mg/mL MnO₂; and (G6) 10% H₂O₂ + 10 mg/mL MnO₂. After analyzing bleaching efficacy (ΔE₀₀ and ΔWI), the degradation kinetics of H₂O₂ and trans-amelodentinal cytotoxicity were determined (n = 8, ANOVA/Tukey; p < 0.05).

RESULTS

G6 presented BE (ΔE₀₀ and ΔWI) statistically similar to G2, which represented conventional in-office bleaching (p = 0.6795; p > 0.9999). A significant reduction in the diffusion of H₂O₂ occurred in G3, G4, G5, and G6 compared to G2 (p < 0.0001). The highest DK of H₂O₂ occurred in G6 (p < 0.0001), which had the lowest TC in comparison with all other bleached groups (p ≤ 0.0186).

CONCLUSION

The addition of 10 mg/mL of MnO₂ in a 10% H₂O₂ bleaching gel potentiates the degradation of this reactive molecule, which increases the BE of the product and decreases TC.

CLINICAL SIGNIFICANCE

Replacing a 35% H₂O₂ gel commonly used for conventional in-office dental bleaching by a 10% H₂O₂ gel containing 10 mg/mL of MnO₂ reduces the cytotoxicity of this professional therapy, maintaining its excellent esthetic efficacy.

Whitening efficacy of low concentration hydrogen peroxide photoactivated with blue or violet LED

BACKGROUND

Bleaching protocols using low concentration hydrogen peroxide (HP) photoactivated with LED sources have been widely discussed. We evaluated the whitening efficacy of 15% HP photoactivated with blue or violet LED compared to 35% HP.

METHODS

Thirty bovine crowns were sectioned into 5 × 5 × 2mm specimens. After staining in black tea, the specimens were randomized into three groups (n=10): 35% HP, 15% HP + blue LED and 15% HP + violet LED. Two bleaching sessions were performed and the color assessment (∆L*, ∆a*, ∆b*, ∆E_ab [CIELab], ∆E₀₀ [CIEDE2000] and WI_D) was performed before, 24h after each session, 7 days and 1 month after the last session. Data were evaluated by two-way repeated measures ANOVA and Bonferroni post-test at a significance level of 5%.

RESULTS

All groups showed effective and similar results over 1 month of follow-up (p > 0.05), with only intragroup differences among the time intervals (p < 0.05).

CONCLUSIONS

The use of 15% HP photoactivated with blue or violet LED showed similar whitening efficacy compared to 35% HP. Thus, the association of low concentration bleaching gels with LED sources can provide a successful and less aggressive treatment in terms of color change.

A Digital Process for Manufacturing Customized Trays for Dental-Whitening Treatments

This study presents an alternative process for designing and manufacturing customized trays for dental-whitening treatments. The process is based on a digitized approach consisting of three main stages: design of a reference model, its manufacturing by AM, and thermoforming of the tray. The aim of the study was to develop a high-performance tray, able to guarantee comfort, safety, and efficacy for whitening treatments. To evaluate the patient’s experience, some tests under real operating conditions were performed. Twenty people carried out a nighttime treatment of 14 days. Each patient was asked to assess the overall level of satisfaction and the comfort of the tray and its ability to retain the gel. Tooth whitening was also determined according to the VITAPAN scale. All patients involved in the study were satisfied and provided positive feedback about comfort and tightness of the tray. At the end of the treatment, 15 out of 20 patients achieved shade A1 on the VITAPAN scale. The mean improvement in color shades was about 7. These results confirmed the great potential of the proposed dental tray. Its use was proven to guarantee a high level of quality, flexibility, and customization of dental-whitening treatments, improving comfort, safety, and efficacy.

Effects of tooth bleaching protocols with violet LED and hydrogen peroxide on enamel properties

BACKGROUND

This study evaluated the color change, enamel surface roughness and microhardness after different tooth bleaching protocols, using hydrogen peroxide (HP) and/or violet LED.

METHODS

Forty bovine specimens (7 × 7 × 2 mm) were randomly distributed into 4 groups: 35% HP, 6% HP, 6% HP + violet LED and violet LED alone. First, the specimens were stained with black tea and then submitted to two bleaching sessions of 30 min with an interval of 7 days. Color change (∆L*, ∆a*, ∆b* and ∆E00) after 24 h of each session and 1 week after the last session was evaluated. Enamel roughness and microhardness were evaluated immediately before the sessions, 24 h and 1 week after the last session. Data were evaluated by ANOVA for repeated measures and Bonferroni post-test or Kruskall-Wallis and Dunn tests (α = 0.05). Representative specimens from each group were analyzed by scanning electron microscopy.

RESULTS

6% HP + violet LED and 35% HP showed the highest color change, while violet LED alone had the lowest results. Enamel roughness analyses showed that 6% HP + violet LED and 35% HP showed changes after two bleaching sessions. No differences were observed regarding enamel microhardness.

CONCLUSIONS

The use of 6% HP + violet LED showed enhanced bleaching efficacy compared to 35% HP. However, violet LED used alone exhibited the lowest color change. 6% HP + violet LED and 35% HP promoted changes on enamel roughness, while no microhardness changes was observed for any group.

Validation of the brazilian version of the oral health impact profile - Aesthetic questionnaire

Abstract The aim of the study was to develop the Brazilian version of the Oral Health Impact Profile - Aesthetic Questionnaire (OHIP-Aes-Braz) and test its psychometric properties. The questionnaire test versions were developed by a panel of experts and a pre-test was conducted in a focus group. Data used for testing its psychometric properties were obtained from a randomized controlled clinical trial on tooth bleaching. Seventy-nine Brazilian adults were included. The questionnaires were applied before tooth bleaching treatment (baseline), one week (T1), and one month after the intervention (T2). Reliability was assessed in terms of internal consistency and stability, while validity was ascertained by criterion and construct validity. The sensitivity to change was assessed comparing the total scores at baseline and T2, using the Wilcoxon test (α = 0.05). Both stability and internal consistency (intra-class correlation coefficient=0.95, Cronbach’s α = 0.92) proved to be adequate. Construct validity was confirmed as the correlation between OHIP-Aes-Braz scores with tooth color satisfaction and self-perceived oral health were in the expected direction. A positive correlation between OHIP-Aes-Braz and OHIP-14 (rs=0.63) and OIDP (rs=0.77) was observed. The instrument was responsive once differences in total scores before and after treatment were statistically significant (p<0.001). The OHIP-Aes-Braz presented good psychometric properties and showed sensitivity to change regarding aesthetics evaluation in Brazilian adults treated with tooth bleaching. A valid and reliable instrument allows a suitable assessment of oral health-related quality of life in Brazilian patients submitted to aesthetics dental interventions.

LED/laser photoactivation enhances the whitening efficacy of low concentration hydrogen peroxide without microstructural enamel changes

BACKGROUND

The association of low concentration hydrogen peroxide (HP) and a light source has been widely used to achieve efficient bleaching. We investigated the colorimetric and microstructural changes of bovine enamel bleached with 6% HP associated or not with a hybrid light source system of violet light and laser (LED/laser).

METHODS

Twenty bovine crowns were used to obtain specimens of 7 × 7 × 2 mm. Then, they were randomized in two groups (n=10): 6% HP and 6% HP + LED/laser. After staining with dark tea solution, three bleaching sessions were performed. Colorimetric evaluation (∆L*, ∆a*, ∆b*, ∆E₀₀ [CIEDE2000] and WI_D) after 24 hours of each session and 7 days after the final bleaching session was performed. Enamel Vickers microhardness at baseline, 24 hours and 7 days after the last bleaching session were also evaluated. Two-way repeated measures ANOVA and Bonferroni post-test was used at a significance level of 5%.

RESULTS

6% HP and 6% + HP LED/laser showed satisfactory bleaching results. The group photoactivated showed higher WI_D values (p<0.05). Differences between groups were observed for ∆E₀₀, ∆L* and ∆a* (p<0.05), except for ∆b* (p>0.05). Intra-group differences were also found (p<0.05). Regarding microhardness, no inter or intra-group differences were observed (p>0.05).

CONCLUSIONS

The photoactivation with LED/laser enhanced the whitening efficacy of 6% HP compared to the group without photoactivation. Thus, the LED/laser activation appears to be a good option when using low concentration HP-based agents. In addition, both bleaching protocols did not cause changes on enamel microhardness.

Influence of Professional Teeth Whitening on Oral Hygiene: Long-term Results

Aims:

The aim of this article is to estimate the long-term influence of professional dental bleaching on quality of oral hygiene (year after procedure).

Materials and Methods:

A randomized controlled prospective clinical repeated study was carried out 6 months after the previous one, i.e., 1 year after the oral hygiene procedure, among 60 patients divided into two groups. In the first group, professional oral hygiene and bleaching using 25% hydrogen peroxide were performed. In the second group only, oral hygiene was performed. Dynamics of hygienic index of Quigley-Hein modified by S. Turesky was estimated.

Results:

In the first group, the average value of the hygienic index of Quigley-Hein modified by S. Turesky was significantly lower a year after procedure than before (1.33±0.09 and 2.34±0.14, respectively). In the second group, this index exceeded 2.45 and nearly returned to the initiated level (2.45±0.07 and 2.44±0.08, respectively). Patients underwent professional teeth whitening in the long-term period, and the level of oral hygiene was significantly higher than that in the control group.

Conclusion:

Professional dental bleaching has good long-term influence on the level of oral hygiene and serves as a significant motivation factor for maintaining health of oral cavity.

One-year follow-up evaluation of reservoirs in bleaching trays for at-home bleaching

OBJECTIVE

To evaluate the color change stability and patient satisfaction after one-year of at-home bleaching with 10% carbamide peroxide (CP) in trays with or without reservoirs.

MATERIALS AND METHODS

Forty-six patients were subjected to bleaching with CP (3 h/daily; 21 days) with a bleaching tray with or without reservoirs. The color was measured one-month and one-year after the completion of bleaching using the spectrophotometer (ΔEab, Δ00 and ΔWi), and shade guide units (ΔSGU). Patients' satisfaction were assessed using a 5-point Likert Scale questionnaire. Data were submitted to paired t-test (α = 0.05).

RESULTS

No significant difference between color change after one-month and one-year was observed (VITA Classical shade guide unit and the ΔWi; p > 0.53). Significant differences were observed for the VITA Bleachedguide 3D-MASTER shade guide, ΔEab and ΔE00 (p < 0.03). The level of patient satisfaction was similar between groups (p = 1.00).

CONCLUSIONS

Bleaching tray design did not have any influence on the bleaching stability for the 10% CP (Opalescence PF, Ultradent). Patients were very satisfied with the bleaching outcomes regardless of the bleaching tray design.

CLINICAL RELEVANCE

Placement of reservoirs in bleaching trays does not increase longevity of dental bleaching. No clinically important color rebound was observed 1 year after bleaching with 10% CP.

Bleaching and microstructural effects of low concentration hydrogen peroxide photoactivated with LED/laser system on bovine enamel

BACKGROUND

Tooth whitening protocols with low concentration hydrogen peroxide (HP) appear to minimize the microstructural effect on teeth. In addition, light sources have been used to enhance bleaching efficiency. This study evaluated the color change and microhardness of a protocol with 6% HP photoactivated by LED/laser in comparison with 35% HP.

METHODS

Twenty bovine incisors were randomized in two groups: 6% HP + LED/laser and 35% HP (n=10). Teeth were submitted to staining using dark tea. Three whitening sessions were carried out according to the manufacturer's instructions. Enamel microhardness (VHN) and color change evaluation (∆L*, ∆a*, ∆b*, ∆E₀₀ [CIEDE2000], and WI_D) before 24 hours and 7 days after the last whitening session were performed. Two-way repeated ANOVA and Bonferroni post-test was used (α = 0.05).

RESULTS

Both groups showed perceptible color changes, being more pronounce for 35% HP. Differences were observed for ∆a*, ∆b* and ∆E₀₀ (p≤0.027), except for ∆L* (p>0.05). Differences were also found in the comparison among the evaluation times within the same group (p≤0.027), except for ∆a* results (p>0.05). WI_D showed that 35% HP exhibited high whiteness values. Regarding microhardness, the groups did not show significant differences (p>0.05). However, 35% HP showed decreased values after 7 days of the last whitening session compared to the baseline (p≤0.027).

CONCLUSIONS

6% HP + LED/laser promoted perceptible color change, but not comparable with 35% HP. No differences on enamel microhardness were observed between the whitening protocols. However, 35% HP showed decreased hardness after 7 days of whitening compared to baseline.

Impact of tooth bleaching on oral health-related quality of life in adults: A triple-blind randomised clinical trial

OBJECTIVE

To investigate the impact of tooth bleaching on oral health-related quality of life (OHRQoL) in adults using a randomised clinical trial comparing at-home and in-office bleaching.

METHOD

A total of 130 individuals were randomly allocated to two groups (n = 65) according to the type of treatment. At-home treatment was performed using 10 % carbamide peroxide (2 h/day; 3 weeks) and an in-office placebo, while 35 % hydrogen peroxide was used for in-office (1/week; 3 weeks) and an at-home placebo. Colour was assessed using the CIELAB system using a digital spectrophotometer. Objective and subjective colour change was estimated by calculating CIEDE2000 (ΔE00) and shade guide units (ΔSGU), respectively. The OHRQoL was measured using the Brazilian version of the Oral Health Impact Profile (OHIP-14). All assessments were performed at baseline and after 21 days. For bivariate analysis, the chi-square test, Student's t-test, and Wilcoxon test were used. The effects of OHRQoL were assessed using distribution-based responsiveness.

RESULTS

Objective colour change was observed at home (p = 0.033), in comparison to in-office (p = 0.429). Mean OHIP-14 scores were similar between groups at baseline (p = 0.368) and after treatment (p = 0.695). Bleaching had a moderate positive effect on the OHRQoL of adults, especially with respect to the psychological discomfort domains, social disability, and total OHIP-14 score. The perception of tooth sensitivity in the group that received at-home treatment was negatively associated with OHRQoL (p = 0.037).

CONCLUSION

The bleaching agents were highly effective and demonstrated a moderate influence on the patients' aesthetic perception and psychosocial impact.

Effectiveness of Whitening Strips Use Compared With Supervised Dental Bleaching: A Systematic Review and Meta-analysis

CLINICAL RELEVANCE

Bleaching performed at home while under the supervision of a dentist provides greater color alteration compared with whitening strips when evaluated with a spectrophotometer, although the color alteration was undetectable by unaided human eyes.

SUMMARY

Objective: A systematic review and meta-analysis were performed to answer the following research question: Does the use of whitening strips (WS) lead to an equivalent color change compared with supervised dental bleaching in patients with permanent dentition?Methods: A search was performed on August 10, 2017 (updated on March 22, 2019), in PubMed, the Brazilian Library in Dentistry, Latin American and Caribbean Health Sciences Literature database, Cochrane Library, Scopus, Web of Science, and SIGLE, without restrictions regarding date or language. Abstracts from the International Association for Dental Research, unpublished and ongoing trial registries, dissertations, and theses were also searched. Only randomized clinical trials (parallel or split mouth) in patients with permanent dentition that compared WS with dentist-supervised dental bleaching performed at home (AH) or in office (IO) were included. The risk of bias (RoB) was evaluated using the Cochrane Collaboration tool. A meta-analysis with subgroup analysis (low and high peroxide concentration) was conducted for color change ΔE* (spectrophotometer) and ΔSGU (shade guide units), risk and intensity of tooth sensitivity (TS), gingival irritation (GI), and patient satisfaction using a random effects model. Heterogeneity was assessed with the Cochrane Q test and I2 statistics. GRADE (Grading of Recommendations, Assessment, Development and Evaluation) was used to assess the quality of the evidence.Results: After the removal of duplicates, followed by title and abstract screening, 20 studies remained. Only two studies were considered to have a low RoB; 11 had a high RoB, and seven had an unclear RoB. For WS versus IO, data were not available for the meta-analysis. For WS versus AH bleaching, a significant difference in ΔE* favoring the AH group was observed (standardized mean difference [SMD] = -0.50, 95% confidence interval [CI] -0.79 to 0.21), but the risk (risk ratio = 0.78, 95% CI 0.65 to 0.93) and intensity of TS (SMD = -0.30, 95% CI -0.56 to -0.04) were lower in the WS group. Color change in ΔSGU, risk and intensity of GI, and patient satisfaction were not significantly different between groups (p>0.20). The quality of evidence for ΔE*, risk and intensity of TS, and intensity of GI were graded as moderate.Conclusion: Although the risk and intensity of TS were lower in the WS group, dentist-supervised at-home bleaching led to a better color change when measured with a spectrophotometer, although the color alteration was undetectable by unaided human eyes.

Oral status and aesthetics after nonsurgical periodontal treatment: Do patient's perception and dentist's evaluation agree?

Objectives

Periodontal healing is often accompanied by side effects, which may cause an aesthetic deficit. The present investigation was focussed to compare patient's subjective perception of their posttherapy aesthetics with the objective measures of the results.

Materials and methods

Survey results from patients (subjective parameters) on oral status and aesthetics were compared against routine clinical parameters and corresponding survey results from treating dentists (objective parameters), both before and after periodontal treatment. Subjective outcome parameters were then suitably transformed and compared with the objective ones to investigate the agreement between patients' perception and actual outcomes.

Results

Objective recordings of periodontal status by the dentist and subjective awareness of the patient are quite contradictory to each other for almost all participants. Further, it was found that their aesthetics in the front were better after treatment, but dentist professionals targeted for future treatment needs.

Conclusions

In this study, it was found that patients improved aesthetically on the upper jaw front after the therapy, which was not shared by the dentists. This discrepancy was due to the clinicians' view on more aesthetic corrective procedures than on patients' need.

Increased whitening efficacy and reduced cytotoxicity are achieved by the chemical activation of a highly concentrated hydrogen peroxide bleaching gel

OBJECTIVE

This study was designed for the chemical activation of a 35% hydrogen peroxide (H2O2) bleaching gel to increase its whitening effectiveness and reduce its toxicity.

METHODOLOGY

First, the bleaching gel - associated or not with ferrous sulfate (FS), manganese chloride (MC), peroxidase (PR), or catalase (CT) - was applied (3x 15 min) to enamel/dentin discs adapted to artificial pulp chambers. Then, odontoblast-like MDPC-23 cells were exposed for 1 h to the extracts (culture medium + components released from the product), for the assessment of viability (MTT assay) and oxidative stress (H2DCFDA). Residual H2O2 and bleaching effectiveness (DE) were also evaluated. Data were analyzed with one-way ANOVA complemented with Tukey's test (n=8. p<0.05).

RESULTS

All chemically activated groups minimized MDPC-23 oxidative stress generation; however, significantly higher cell viability was detected for MC, PR, and CT than for plain 35% H2O2 gel. Nevertheless, FS, MC, PR, and CT reduced the amount of residual H2O2 and increased bleaching effectiveness.

CONCLUSION

Chemical activation of 35% H2O2 gel with MC, PR, and CT minimized residual H2O2 and pulp cell toxicity; but PR duplicated the whitening potential of the bleaching gel after a single 45-minute session.

The effects of at-home whitening on patients' oral health, psychology, and aesthetic perception

BACKGROUND

The aesthetic self-perception and psychosocial impact of whitening is poorly explored in the literature; it is even less clear whether the effect of whitening may influence the psychology or social relations of patients. Therefore, the aim of this trial is to evaluate the impact of an at-home whitening procedure on patients' quality of life. Also, this study's secondary objective is the adaptation and validation of the Spanish version of the OES questionnaire (OES-SP).

METHODS

Fifty eight patients underwent whitening with 10% carbamide peroxide (CP) gel for 1 h daily for 3 weeks. For these participants, the OHIP-Esthetics, PIDAQ, and OES surveys were applied before, one week after, and one month after the whitening procedure. Oral health-related quality of life was measured using the OHIP-Esthetics survey and the psychosocial impact using the PIDAQ survey. The orofacial aesthetics was measured by OES and validated for the Spanish Chilean context. The treatment efficacy (ΔE and ΔSGU) and data from the OHIP-Esthetics PIDAQ and OES surveys were compared using the Wilcoxon Signed-Rank test.

RESULTS

The whitening procedure was effective (ΔE = 5.9 ± 1.8). The OHIP-Esthetics results were significant when comparing the initial baseline survey prior to the treatment and one week after whitening (p < 0.001) and when comparing the baseline and one-month results (p < 0.001). The overall score on the PIDAQ, after one week post-whitening, was separated into factors and all factors were statistically significant (p < 0.03); the factors for the one-month results were also all statistically significant (p < 0.001), except the social impact factor. The OES questionnaire had statistically significantly increased scores both one week and one month post-treatment (p < 0.0001). The reliability, validity, and responsiveness of the OES-SP were satisfactory.

CONCLUSION

The at-home whitening procedure with carbamide peroxide 10% had a positive effect on patients' oral health-related quality of life, psychology, and aesthetic perception after one month post-whitening. The Chilean Spanish version of the OES showed satisfactory psychometric characteristics to evaluate dental whitening.

TRIAL REGISTRATION

NCT02605239 . Date that the study was retrospectively registered: 11-11-2015.