The effect of bleaching applications on stained bulk-fill resin composites

Effect of food-simulating liquids and polishing times on the color stability of microhybrid and nanohybrid resin composites

The aim of this study was to evaluate the effect of food-simulating liquids and polishing times on the color stability of microhybrid and nanohybrid resin composite materials. One nanohybrid (Compofill) and one microhybrid (Dynamic plus) were used to prepare 120 samples each. Three polishing time subgroups were randomly assigned to each composite group. The polishing groups were treated with a one-step polishing system (Dimanto). Based on food-simulating liquids, the polishing groups were each separated into four subgroups (n = 10): ethanol, heptane, citric acid, and distilled water. Color change was evaluated by immersing the resin composites in liquids simulating food for 7 and 14 days. Three-way ANOVA was used for data analyses. When the color changes of the resin composites were compared, Compofill showed the lowest color change at baseline-7 days and baseline-14 days. In terms of food-simulating media, all times, the immersion in ethanol resulted in higher color variation compared to distilled water and citric acid while heptane showed an intermediate behavior. The nanohybrid composite showed less discoloration than the microhybrid composite. The discoloration of the nanohybrid resins after 7 and 14 days was below the clinically acceptable level. At all times, the increase in polishing time contributed to color stability.

Effect of Staining and External Bleaching on the Color Stability and Surface Roughness of Universal-Shade Resin-Based Composite

Aim

This study evaluated the color stability and surface roughness of two universal-shade compared to two nanohybrid composites after staining and external bleaching with 40% hydrogen peroxide.

Methods

Two universal shade resin-based composites and two nanohybrid composites were tested. Twenty disc-shaped specimens from each material were fabricated and divided into two subgroups: one group was stained and bleached (staining group) and the other received bleaching treatment only (control group). The staining group was stained with coffee solution for 24 h. Subsequently, each sample of all four materials was bleached using an in-office bleaching gel using 40% hydrogen peroxide. Color measurements were performed using a spectrophotometer to obtain the International Commission on Illumination parameters, L*; a*; and b* for each of the following periods: baseline, after bleaching, and two weeks after bleaching for the control group. The staining group was examined at baseline, after staining, after bleaching, and two weeks after bleaching. Surface roughness (Ra) of all the materials after each treatment step were also recorded. The data was statistically analyzed using SPSS 26.0 statistical software. Changes were considered statistically significant at P = 0.05.

Results

Descriptive statistics (means and standard deviations) were used to describe color measurements and surface-roughness values. Two-analysis of variance and one-way analysis of variance were used to compare the mean values of surface roughness, L*a*b*and ΔE00 values. Statistically significant differences and clinically acceptable ΔE00 were observed between all materials during the different stages in color measurements, whereas the surface roughness was significantly different for each study material and treatment mode.

Conclusion

Staining with coffee solution and external bleaching produced acceptable color changes for all materials tested. Staining and bleaching increased the surface roughness values of the tested resin-based composites.

Effect of bleaching and repolishing on whiteness change and staining susceptibility of resin-based materials

BACKGROUND

The aim of this study was to investigate the effects of different types of bleaching methods and repolishing on the whiteness index and staining susceptibility of additive and subtractive production resin-based materials and direct composite resins.

METHODS

In this study, a total of 96 samples (8*8*2m) were prepared using a nanohybrid composite resin (Neo SpectraTM-ST (NS)), a subtractive-manufactured nanoceramic resin (CerasmartTM270 (CS)), and an additive-manufactured permanent resin (Saremco print Crowntec (CT)). The samples were randomly divided into four treatment groups: control (distilled water, 14 days), in-office bleaching (Opalescence Boost-40% HP, 3*20min), at-home bleaching (Opalescence PF-16% CP, 6 h, 14 days), and toothpaste group (Opalescence Whitening, 2*5min, 14 days) (n:8). After each the bleaching procedure was completed, the samples were kept in coffee solution for 7 days. Following, all samples were repolished. The color of the samples was measured with a spectrophotometer at baseline (T0), after bleaching (T1), after staining in coffee (T2) and after repolishing (T3). The whiteness index change (∆WID, T1-T0), staining susceptibility (∆E1, T2-T1) and color change after repolishing (∆E2, T3-T1) of the samples were calculated in the CIE (Commission International De I'Eclairage) system. The data were analyzed by SPSS software One-Way ANOVA, post-hoc Tukey, post-hoc Tamhane's-T2 and Paired-samples T test (α = 0.05).

RESULTS

The ∆WID of all tested materials was significantly different in the in-office bleaching group compared to the control group (p < 0.05). Among the bleaching groups, the highest ∆WID was obtained in-office bleaching group of CT (2.91 ± 4.12). Staining susceptibility after bleaching (∆E1) was higher in the in-office and at-home bleaching groups compared to the control group in all tested materials. However, the difference between the treatment groups was statistically significant in NS and CS (p < 0.05). The highest ∆E1 was obtained in the in-office group of CT (7.36 ± 4.82). Color changes after repolishing (∆E2) of the tested materials were less in all groups compared to ∆E1.

CONCLUSION

In-office and at-home bleaching can increase the whiteness index change and stain susceptibility of materials. Among the tested materials, the color stability of additive-manufactured CT was comparatively poorer. The repolishing was found to be beneficial in reducing staining.

The Impact of Modeling Liquids on Surface Roughness and Color Properties of Bulkfill Resin Composites After Simulated Tooth Brushing: An in Vitro Study. Part I

OBJECTIVE

To evaluate the effect of different modeling agents on color changes, surface roughness, and translucency parameters over time in Bulkfill resin composites.

MATERIAL AND METHODS

Sixty specimens were prepared using three Bulkfill resin composites (Tetric N-Ceram Bulkfill, Filtek One Bulkfill and Opus Bulkfill) and three modeling agents (Wetting Resin, Optibond FL and Ambar APS). All specimens were subjected to a simulated tooth-brushing (Baseline, 50.000 cycles, 100.000 cycles), and surface roughness was measured at each interval. Surface topography was evaluated. The translucency parameter and color changes were assessed after 24-h, 7-, 14- and 30-day immersion in water, wine, and coffee. Data was analyzed using ANOVA and Bonferroni test.

RESULTS

All specimens increased roughness after simulated tooth-brushing (p < 0.05). Wetting Resin decreased roughness on Tetric N-Ceram Bulkfill (p < 0.05). The translucency parameter remained unaltered for all groups. All groups changed color after 30-days of immersion in wine and coffee (p < 0.05). Ambar APS and Wetting Resin on Tetric N-Ceram Bulkfill showed higher color changes when immersed in coffee (p < 0.05).

CONCLUSION

The use of modeling agents does not jeopardize translucency properties but may affect surface roughness and color properties of Bulkfill resin composites depending on their composition.

CLINICAL SIGNIFICANCE

The findings of this study suggest that surface roughness and color properties are affected by the differences in the composition between modeling agents and Bulkfill resins composites.

Effectiveness of Papain-Based Organic Dentifrices Versus Commercial Whitening Dentifrice on Tea-Induced Tooth Stains: An In Vitro Study

INTRODUCTION

Tooth discoloration is a common issue for oral health practitioners. Whitening treatments remove surface and deep stains using either chemicals or over-the-counter products. Due to harmful chemical effects, organic whitening products are increasingly preferred. This study compared the effectiveness of organic papain-based dentifrices (Perfora Magic Teeth Whitening Serum, Gurugram, India) on tea stains to commercially available Colgate whitening dentifrices (Colgate-Palmolive, New York, NY).

METHODS

Sixty maxillary central incisors for periodontal reasons were used and divided into two groups. Each sample was soaked in freshly brewed tea for 10 minutes daily and stored in artificial saliva (Nanochemazone, Kurukshetra, India) for 24 hours. After four weeks, group 1 was treated with papain-based dentifrices, and group 2 with Colgate Visible White teeth whitening paste (CVWP) daily for four weeks. Spectrophotometric analysis (VITA Easyshade V, VITA Zahnfabrik, Bad Säckingen, Germany) was performed pre-treatment and at four weeks post-treatment. Data were compiled and statistically analyzed.

RESULTS

Compared with group 1, group 2 exhibited an optimal color change (ΔE). Statistically significant differences were observed between the mean ΔL (lightness) and Δb (blueness -b or yellowness +b) values.

CONCLUSION

CVWP showed better color achievement and stain reduction due to abrasive and peroxide components. Although Perfora Teeth Whitening Serum has low efficacy in upgrading the color of the enamel surface, it is safe for long-term use.

Investigating the Mechanisms of Discoloration in Modern Dental Materials: A Comprehensive Characterization Approach

In general, patients' opinions on reaching ideal esthetics while restoring dental tissues is one of the most important part of the oral treatment. Unfortunately, discoloration of dental materials may occur due to intrinsic and extrinsic factors. The aim of the study was to evaluate the color stability of frequently used dental resin materials and determine the mechanism of their discoloration. The study used various characterization techniques (optical microscopy, Fourier-transform infrared spectroscopy, low-temperature N2 adsorption, diffuse reflectance spectroscopy, and luminescence) to understand the effect of surface defects on discoloration. The adsorption of model liquids on the surface was confirmed to be related to the increase in BET surface area. The study found that the adsorption of discolorants, such as coffee, tea, and wine, on the surface of the dental material follows the multilayer BET model. When the surface is smooth, the discoloration is usually within acceptable limits, with a maximum of ∆E = 3.3. The discoloration made by tea and demineralized water was within acceptable limits even after 7 days of exposure.

Effect of aging and bleaching on the color stability and surface roughness of a recently introduced single-shade composite resin

OBJECTIVES

To assess the effects of aging and bleaching procedures on the color stability and surface roughness of a new single-shade composite versus multi-shade composite resins.

METHODS

A single-shade composite resin (Charisma Diamond One, CDO) and 3 multi-shade composite resins (Tetric NCeram, Filtek Z350 XT, Clearfil Majesty Posterior) were tested. Thirty specimens of each material were subjected to one of the aging procedures respectively: immersion in distilled water (12 days/37 °C), immersion in coffee (12 days/37 °C), or water thermocycling (10,000 cycles/5-55 °C). All specimens underwent in-office bleaching after aging. Kruskal-Wallis tests and analysis of variance were used for statistical analysis (α=0.05).

RESULTS

All materials exhibited a change of color (ΔE00), translucency (RTP), whiteness (WID) and surface roughness parameters (Sa,Sv) after aging and bleaching procedures. CDO showed the highest ΔE00 among all resins with the highest RTP value, regardless of the aging procedures. Immersion in coffee led to the significantly highest ∆E00 values and lowest RTP values for nearly all resins. Positive ΔWID1 (WID(bleaching)-WID(baseline)) values were found in distilled water immersion and thermocycling groups, while negative ΔWID1 values were found in the coffee immersion group for all materials. Besides, positive ΔWID2 (WID(bleaching)-WID(aging)) values were found in all aging groups for nearly all materials. All materials showed an increasing trend in Sa and Sv after bleaching.

CONCLUSIONS

CDO showed more pronounced discoloration than multi-shade composite resins. Although the whiteness of all resins increased after bleaching, none was completely restored in the coffee immersion group. Bleaching significantly increased the surface roughness of all materials.

CLINICAL SIGNIFICANCE

Charisma Diamond One is more susceptible to discoloration, which may affect its long-term success rate. Bleaching could partially reduce the color change of the composite resins but did not return them completely to their original state. The roughness of the resins increased after bleaching, prompting dentists to repolish them after bleaching.

The effect of tooth bleaching using violet LED (405-410 nm) on the properties of resin-based composites

BACKGROUND

The objective of this study was to evaluate the effect of bleaching techniques, including or not the use of violet light (405-410 nm), on resin-based composites' color, surface roughness, nanohardness, and elastic modulus.

METHODS

Ninety-six disk-shaped specimens (12 mm x 2 mm; n = 12) were prepared using Filtek Z350 XT (Z350) and IPS Empress Direct (ED) resin-based composites. After 24 h, specimens were stained in red wine for 28 days. After staining, specimens were divided into four experimental groups: 40 % Hydrogen Peroxide (HP); Violet Light (VL); 40 % Hydrogen Peroxide associated with Violet Light (HP+VL), and a control group - no treatment (NT). Specimens were evaluated at six experimental times: initial (24 h after light curing); after staining and after the 1st, 2nd, 3rd, and 4th bleaching sessions regarding the color change (ΔE00, L*, a*, b*, and WID); roughness (Ra), nanohardness and elastic modulus (GPa). Two-way analysis of variance for repeated measures was performed (α=0.05 %).

RESULTS

There was a statistically significant difference between staining and the 1st bleaching session for all ED groups (p<0.05). After the last bleaching session, there were no differences between the experimental and the control groups of both resin-based composites. Bleaching using violet light did not change the roughness, nanohardness and elastic modulus of the tested resin-based composites (p>0.05).

CONCLUSIONS

Although hydrogen peroxide and violet light remove pigments from resin-based composites without affecting their surface roughness, nanohardness, and elastic modulus, the color change was similar to the one obtained by immersion in distilled water.

Effect of Laser and Conventional Office Bleaching and Polishing on the Color Change of Stained Nanohybrid and Microhybrid Composite Resin

Aim

The present study investigated the effects of laser and conventional in-office bleaching, and polishing on the color of stained composite resin.

Materials and Methods

A microhybrid composite (Clearfil AP-X) and a nanohybrid composite (Grandio) were selected. Twenty-four discs (2 × 10 mm) for each composite were prepared. The samples were immersed in coffee solution (25 g of coffee in 250 mL water) for seven days. Then the samples were divided into three groups (n = 8) and the stains were removed using bleaching (with Opalescence Xtra Boost), diode laser irradiation with Heydent material and a Sof-Lex polishing kit. The L ∗a ∗b ∗ color parameters were determined using a spectrophotometer before and after immersion and after stain removal procedures, and the overall color changes (ΔE) were calculated. The data were analyzed with two-way analysis of variance.

Results

In the Clearfil composite resin group, the mean ΔE compared to the baseline using in-office bleaching, laser irradiation, and Sof-Lex polishing kit were 3.31, 3.35, and 4.93, respectively. These values with the Grandio composite resin were 3.31, 6.35, and 4.57, respectively. The highest capacity to remove stains was related to the conventional in-office bleaching method. Grandio composite resin underwent more color changes than Clearfil composite resin significantly (P-value < 0.05).

Conclusion

Both composite resins exhibited color changes after immersion in the discoloring solution. However, after staining-removing procedures, the ΔE values decreased. Decreases in the ΔE values were not sufficient to restore the color to that before immersion in the discoloring solution with any stain-removing methods.

Colour Parameters and Changes of Tea-Stained Resin Composite Exposed to Whitening Pen (In Vitro Study)

BACKGROUND

One of the crucial factors influencing the longevity of anterior aesthetic dental restorations is the colour stability of resin composites. Bleaching and whitening have become popular methods for enhancing dental aesthetics. Home whitening techniques, such as special pens, are widely available commercially. This in vitro study aimed to determine the efficiency of a whitening pen in removing tea stains from resin composite by measuring colour differences (ΔE₀₀). Additionally, the study aimed to evaluate the variations in colour parameters measured by extra-oral and intra-oral spectrophotometers.

METHODS

A total of 45 disc-shaped resin composite specimens were randomly divided into three groups; Group 1: stored in artificial saliva (control), Group 2: stored in artificial saliva followed by a whitening pen application, and Group 3: stored in tea followed by a whitening pen application. Colour measurements were taken three times for each specimen using two spectrophotometers (extra-oral and intra-oral devices); T1: before storage (baseline), T2: after storage in artificial saliva or tea for 6 days; and T3: after one week of whitening pen application in groups 2 and 3. The data were statistically analyzed using one-way ANOVA followed by the Tukey post hoc test (p ≤ 0.05). The independent sample t-test was also employed. The equation of CIEDE2000 (ΔE₀₀) was used to calculate the colour difference between the dry, as-prepared specimens (baseline), and those after storage or bleaching. The colour changes exceeding the acceptability threshold (∆E₀₀ = 1.8) were considered unacceptable.

RESULTS

After whitening, the colour of the specimens stored in brewed tea (Group 3) remained unacceptable, as indicated by both the extra-oral and intra-oral spectrophotometers (ΔE₀₀ = 4 and 2.9, respectively). Groups 1 and 2 exhibited lower ΔE₀₀ values than Group 3 (p = 0.01 *). No significant difference was observed between Group 1 (stored in artificial saliva) and Group 2 (stored in artificial saliva and then bleached) (p = 0.3). Significant differences were consistently observed between the data obtained from the extra-oral spectrophotometer and the intra-oral one.

CONCLUSIONS

The whitening pen proved ineffective in removing tea stains from resin composites. Although significant differences were found between the values obtained by the two spectrophotometers (extra-oral and intra-oral), both devices confirmed the unacceptable colour of the tea-stained resin composites after whitening.

Effect of Bleaching Agents on Discoloured Resin-Based Composites for Direct Restorations: A Systematic Review

The purpose of the review was to assess the influence of office and home bleaching on the color durability after staining of resin-based composites (RCs) for direct restorations. A web-based search for possibly relevant scientific papers in the English language between January 2013 and August 2022 was conducted in the databases such as PubMed, Scopus, Cochrane Library, and EMBASE. In-vitro studies that explored the influence of in-office and other bleaching treatments on the discolored RC for direct restorations in extracted human teeth were included. Case studies, case series, animal studies, systematic reviews, and letters to the editor were not considered. A total of 212 articles from a web-based search and 32 studies from a manual search were retrieved. After removal of duplicate records, 181 titles and abstracts were reviewed for eligibility; 92 were chosen for full-text analysis, and nine in-vitro studies matched the inclusion criteria. The two examiners examined the methodological quality of the selected studies independently based on the study design, methodological soundness, and data analysis. Distinct values were assigned to studies evaluating color variations of stained RC subjected to bleaching agents. The methodological quality scores were expressed as a percentage of the highest possible score based on the established scoring system and categorized as indicating a low, moderate, and high level of evidence. The reversal of color alterations following home and office bleaching was found to be dependent on the RC used. Within the limitations of the in-vitro investigations, it was deduced that the bleaching agents were successful in eliminating stains and improving the durability of the color to near baseline values.

Effect of Different Bleaching Methods on Monomer Release from Aged Microhybrid and Nanohybrid Resin Composites

Introduction

Recently, the application of laser-assisted bleaching has increased in dental practice. This method might affect the physical and chemical properties of resin composite and its monomer release. This study aimed to evaluate the effect of in-office, at-home, and laser-assisted bleaching on the monomer release (bisphenol A diglycidyl dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), and urethane dimethacrylate (UDMA)) from aged nanohybrid (Grandio, Voco) and microhybrid (Clearfil AP-X Esthetics, Kuraray) resin composites.

Methods

Thirty-two samples of each composite were prepared. The samples underwent aging procedure with UV light at 65°C for 100 hr. The samples were divided into 4 groups: OB: conventional in-office bleaching with Opalescence Boost PF 40% gel; HB: home bleaching with Opalescence PF 15% gel; LB: bleaching with JW Power bleaching gel followed by diode laser application; and C: control group without bleaching. Then, the samples were immersed in a solution containing 75% ethanol + 25% distilled water. The medium was renewed after 8, 16, 24 hr, and 7 days and was analyzed using high-performance liquid chromatography method to evaluate the monomer release. The data were analyzed using Two-way ANOVA and Post hoc Tukey test.

Results

The bleaching method had no effect on TEGDMA and BisGMA release in both composites while it affected UDMA release in nanohybrid composite; UDMA release was significantly higher in LB compared to control and also higher in OB and LB compared to HB. No difference was observed in the microhybrid composite in this regard.

Conclusion

Laser-assisted bleaching did not affect monomer release from microhybrid composite while it increased UDMA release from nanohybrid composite. The bleaching method had no effect on TEGDMA and BisGMA release.