Whiteness Index For Dentistry Research Articles

Tooth sensitivity in different arches post in-office dental bleaching: A multicenter randomized controlled trial

ObjectiveTo compare the risk and intensity of tooth sensitivity (TS) and gingival irritation (GI), as well as bleaching efficacy (BE) in the maxillary and mandibular arches after in-office dental bleaching. Materials and Methods90 participants were randomly into two groups according to the arch (maxillary or mandibular) in which the patient will first receive a 35 % hydrogen peroxide gel (2 sessions; 1 × 30 min; 1 week apart). TS and GI were recorded immediately after, up to 1 h, 24 h and 48 h after bleaching, using the 0–10 Visual Analogue Scale (VAS). BE was assessed before bleaching and 30 days after the end of the treatment (shade guide units [ΔSGU], CIELab [ΔEab], CIEDE2000 [ΔE00], and Whiteness Index for Dentistry [WID]). TS and GI were compared using McNemar's and paired t-test. BE were compared with Wilcoxon Signed Rank Test (ΔSGU) and paired t-test (ΔEab, ΔE00, and WID) (α = 0.05). ResultsThe risk and the intensity of TS was statistically higher for the mandibular arch (p < 0.003). The risk and intensity of GI did not differ between arches (p > 0.38). Both arches demonstrated significant BE (ΔSGU, ΔEab, ΔE00 and WID), without differences between them (p > 0.08). ConclusionsIn-office dental bleaching induces higher risk and the intensity of TS in the mandibular arch when compared to maxillary arch, without significant differences in gingival irritation, or bleaching efficacy. Clinical RelevanceMost patients experience tooth sensitivity regardless of the dental arch involved. However, when performing in-office dental bleaching, clinicians should consider that the mandibular arch is more likely to experience greater sensitivity compared to the maxillary arch.

Optical properties of advanced lithium disilicate.

A variety of firing protocols are available for the IPS e.max lithium disilicate (LD) and can be used for new, 'advanced' LD (ALD). However, the impact of firing protocols on the optical properties of ALD is still unknown. The aim of the present study was to evaluate the color difference (ΔE00), the translucency parameter (TP00) and the whiteness index for dentistry (WID) for both LD glass ceramics after the processes of firing/glazing. Fifty disk-shaped specimens, with a diameter of 10 mm and a thickness of 1.2 mm, were fabricated from IPS e.max CAD (LD; Ivoclar) and another 50 from CEREC Tessera™ (ALD; Dentsply Sirona). The specimens from each group were further divided into 5 subgroups (n = 10) according to the firing/glazing protocol applied: crystallization (c); one-step crystallization and glazing (cg); crystallization and refiring (c-r); two-step crystallization and glazing (c-g); or long-firing crystallization (lfc). The ΔE00, TP00 and WID were assessed. The statistical analysis of ΔE00 was performed using the one-way analysis of variance (ANOVA) and Tukey's post hoc test, while TP00 and WID were analyzed with the two-way ANOVA and Tukey's post hoc test at a statistical significance level of 0.05. The cg groups were designated as the reference. The ANOVA showed that the firing procedures had no effect on ΔE00, TP00 and WID in the case of LD. In addition, LD exhibited greater translucency and brightness as compared to ALD. For ALD, all color changes observed in relation to the reference firing protocol were clinically unacceptable. The ALD specimens which underwent 1 standard firing cycle showed higher TP00 and WID values than other ALD groups. The choice of the firing protocol has no impact on the color, TP00 or WID of LD. Additionally, LD presents higher WID values than ALD, irrespective of the firing protocol used. Alternative firing protocols result in clinically unacceptable color variations when compared to the manufacturer-recommended protocol for ALD. Advanced LD is more sensitive to different firing protocols with regard to its optical properties, which makes the workflow less predictable in comparison with LD.

Enhancing the Opacity of Glass Ceramics by Applying Opaque Stains to the Intaglio Surface.

The aim of this study was to assess the effect of opaque stain application to the intaglio surface of lithium disilicate glass ceramics on the masking ability of discolored substrates and bond strength to a resin-based luting agent (depending on etching time); the stain film-thickness was also assessed. Ceramic specimens were produced with CAD-CAM blocks of lithium disilicate (IPS e.max CAD). Two opaque stains were tested at ceramic intaglio surface: opaque glassy stain for titanium frameworks (OP-ti) and low-fusion glassy stain for ceramic characterization (LFG-iv). Non-stained ceramic specimens served as controls. For optical and colorimetric analyses, A2-shaded ceramics of medium and low-translucencies were tested, in thicknesses of 1.0- and 1.5-mm (n = 10), with two coupling agents (non-shaded-glycerin and A2-shaded try-in paste). CIEDE2000 formula was used for calculation of translucency parameter (TP00) and color differences (ΔE00). Whiteness index for dentistry (WID) was also reported. ΔE00 were assessed over discolored substrates (tooth-shaded A2-reference, A4, C3, and C4; coppery metal, silvery metal, white zirconia, and PEEK). Microshear bond strength of stained and non-stained ceramic specimens to a resin-based luting agent was evaluated. Film-thickness of stains was assessed by scanning electron microscopy. The application of opaque stains to the intaglio surface of lithium disilicate ceramics resulted in significant reduction of TP00 (p < 0.001) and WID (p < 0.001) and differences in L*, C*, and ho color coordinates (especially with OP-ti) (p < 0.001). ΔE00 was significantly reduced in stained ceramic groups in comparison with the control, for all discolored substrates (p < 0.001). Acceptable color matching was obtained with stained ceramic specimens for all discolored substrates, depending on the type of stain, ceramic thickness, ceramic translucency, and coupling agent. The application of stains to the ceramic intaglio surface was not detrimental to bond strength to a resin-based luting agent, but depended on the time of hydrofluoric acid-etching (20 s for OP-ti and 60 s for LFG-iv) (p < 0.001). Film-thickness of stains presented mean values <70 μm. The application of opaque stains to the intaglio surface of lithium disilicate glass ceramics was effective to mask severely discolored substrates, presenting adequate bond strength to the luting agent and thin film-thicknesses. For indirect restorations over severely discolored substrates, the application of opaque stain to the intaglio surface of lithium disilicate glass ceramic ensures acceptable color matching, with adequate bond strength to resin-based luting agents and clinically acceptable stain film-thickness.

Enhanced tooth bleaching with a hydrogen peroxide/titanium dioxide gel

BackgroundThis study aimed to explore the effects of the titanium dioxide (TiO2) concentration and particle size in hydrogen peroxide (HP) on tooth bleaching effectiveness and enamel surface properties.MethodsTiO2 at different concentrations and particle sizes was incorporated into 40% HP gel to form an HP/TiO2 gel. The specimens were randomly divided into 8 groups: C1P20: HP + 1% TiO2 (20 nm); C3P20: HP + 3% TiO2 (20 nm); C5P20: HP + 5% TiO2 (20 nm); C1P100: HP + 1% TiO2 (100 nm); C3P100: HP + 3% TiO2 (100 nm); C5P100: HP + 5% TiO2 (100 nm); C0: HP with LED; and C0-woL: HP without LED. Bleaching was conducted over 2 sessions, each lasting 40 min with a 7-day interval. The color differences (ΔE00), whiteness index for dentistry (WID), surface microhardness, roughness, microstructure, and composition were assessed.ResultsThe concentration and particle size of TiO2 significantly affected ΔE00 and ΔWID values, with the C1P100 group showing the greatest ΔE00 values and C1P100, C3P100, and C5P100 groups showing the greatest ΔWID values (p < 0.05). No significant changes were observed in surface microhardness, roughness, microstructure or composition (p > 0.05).ConclusionsIncorporating 1% TiO2 with a particle size of 100 nm into HP constitutes an effective bleaching strategy to achieve desirable outcomes.

Influence of Thickness on the Translucency Parameter and Whiteness Index of Single-Shade Resin Composites.

The study aimed to evaluate the effect of thickness on the translucency parameter (TP) and whiteness index for dentistry (WID) of single-shade resin composites compared with a multi-shade resin composite after thermocycling. A total of 100 resin composite samples of five brands (Filtek Z250, Omnichroma, Vittra APS Unique, Zenchroma, and Charisma Diamond One) with thicknesses of 2 mm and 4 mm were prepared (n=10). CIE L*a*b* coordinates were obtained using a spectrophotometer. The resin composite samples were subjected to 10,000 thermocycles. Before and after thermocycling, TP values were calculated with the CIEDE2000 formula, and whiteness values were calculated using the WID. The influence of thickness, resin composite, and aging on these variables was analyzed using the generalized linear model (p<0.05). Omnichroma and Filtek Z250 exhibited, respectively, the highest and the lowest TP00 values compared with the other resin materials (p<0.001). The TP00 values of Zenchroma and Diamond One were similar (p>0.05). Vittra APS Unique had a lower TP than Zenchroma and Diamond One (p<0.001). Before thermocycling, the highest WID showed the combination of Vittra APS Unique with thicknesses of 2 mm (48.33±1.18). After thermocycling, the highest WID was shown in the combination of Vittra APS Unique with thicknesses of 2 mm (45.33±0.55) and 4 mm (46.23±0.94) (p<0.001). After thermocycling, the lowest WID was for the combination of Filtek Z250 with thicknesses 2 mm (21.16±0.93) and 4 mm (20.70±0.91) (p<0.001). The TP and WID values of the resin composites varied across different composites and thicknesses. Single-shade resin composites of different thicknesses demonstrated higher translucency and whiteness values than multi-shade resin composite, both before and after thermocycling.

Development of toothpaste formulations containing mineral clays as abrasive agents and their effects on the physical properties of dental enamel.

To assess the physical properties and topographical aspect of dental enamel's surface microhardness (KHN), surface roughness (Ra), and color parameters CIELAB (∆Eab*), CIEDE 2000 (∆E00), and whiteness index for dentistry (∆WID) after toothbrushing with experimental toothpaste formulations with the following mineral clay types: kaolin, Sparclay SGY, and Tersil CGY used as abrasive component. Scanning electron microscopy (SEM) was performed for topographical analyses purposes. A total of 96 bovine incisors were used in the experiment. They were divided into eight experimental groups (n = 12), namely: NC-negative control (no treatment), CT12-Colgate Total 12®, CMP-Colgate® Máxima Proteção Anticáries, K-kaolin experimental toothpaste, SGY-Sparclay SGY experimental toothpaste; CGY-Tersil CGY experimental toothpaste, SD-SiO2 experimental toothpaste, and CC-CaCO3 experimental toothpaste. All samples were subjected to mechanical brushing protocol with 5000 cycles and kept in artificial saliva with daily exchanges. KHN was analyzed through the mixed linear model for repeated measures over time. Ra was analyzed through nonparametric Kruskal Wallis and Dunn tests to compare the groups. Paired Wilcoxon test was run to compare experimental times. ∆WID, ∆Eab*, and ∆E00 were analyzed through Kruskal Wallis and Dunn tests. All analyses were performed in R* software, at 5% significance level. EXP_SGY recorded higher KHN than EXP_SiO2 and EXP_CaCO3, whereas EXP_K showed increased Ra in comparison to CMP (p = 0.0229). ∆Eab and ∆E00 were significantly higher in the CT12, EXP_SiO2, and EXP_CaCO3 groups than in the NC and EXP_K (p < 0.0001). There were no significant changes in ∆WID (p = 0.0852). According to SEM results, toothbrushing with experimental toothpastes added with mineral clay types did not have significant impact on enamel's polishing and smoothness. CLINICAL RELEVANCE: Mineral clays have a broad application in the cosmetic industry, and recently, they have been used in the formulation of vegan toothpaste.

E-cigarettes and heated tobacco products impact on dental color parameters

ObjectivesAbstaining from tobacco smoking may not only improve general health, but also reduce teeth staining and restore teeth whiteness. Compared with conventional cigarettes, E-cigarettes (ECs) and heated tobacco products (HTPs) may offer substantial reduction in exposure to pigmented tar-like compounds of cigarette smoke. It is possible that improvements in dental color indices may be observed in those who have stopped smoking combustible cigarettes by switching to tar-free nicotine delivery products. MethodsThis cross-sectional study evaluated and compared dental color parameters by digital spectrophotometry among five different groups: individuals who currently smoke ; individuals who used to smoke but have quit ; individuals who have never smoked ; exclusive users of electronic cigarettes (former smokers) ; and exclusive users of heated tobacco products (former smokers) . ResultsDental whiteness in current cigarette smokers was notably worse compared with never and former smokers, (13.38 Whiteness Index for Dentistry (WID) units vs. 19.96 and 16.79 WID units). Remarkably high WID values (i.e., whiter teeth) were also observed in ECs (16.72 WID units) and HTPs users (17.82 WID units). Compared to current smokers, difference in dental whiteness for ECs and HTPs users was visually noticeable (ΔWID difference being on average > 2.90 units). The colour differences measured as delta E*(ΔE*) were all visually detectable except for the comparison between ex-smokers and ECs users for which no perceptible color difference was observed (0.415). ConclusionExclusive use of ECs and HTPs is associated with better dental color measurements than current smoking, suggesting that tar-free nicotine delivery technologies are unlikely to have negative effects on dental appearance. Clinical significanceUse of alternative nicotine delivery systems may be associated with cosmetic benefits with important implications for those smokers perceiving dental aesthetics as a significant problem. For these an oral-based narrative may be a much more significant reason to refrain from smoking than the fear of developing smoking-related diseases in future.

Reliability of the color measurement of resin composites using images obtained using a stereoscopic loupe.

This study assessed the reliability of a color measurement method using images obtained from a charge-coupled device (CCD) camera and a stereoscopic loupe. Disc-shaped specimens were created using the composite Filtek Z350 XT (shades DA1, DA2, DA3, and DA4) (n = 3). CIELAB color coordinates of the specimens were measured using the spectrophotometer SP60 over white and black backgrounds. Images of the same specimens were taken using a CCD camera attached to a stereoscopic loupe. The color of the image was measured (red-green-blue [RGB]) using an image processing software and converted to CIELAB coordinates. For each color coordinate, data from images were adjusted using linear regressions predicting those values from SP60. The whiteness index for dentistry (WID) and translucency parameter (TP00) of the specimens as well as the color differences (ΔE00) among pairwise shades were calculated. Data were analyzed via repeated-measures analysis of variance and Tukey's post hoc test (α = 0.05). Images obtained using the loupe tended to be darker and redder than the actual color. Data adjustment resulted in similar WID, ΔE00, and TP00 values to those observed for the spectrophotometer. Differences were observed only for the WID of shade DA3 and ΔE00 for comparing DA1 and DA3 over the black background. However, these differences were not clinically relevant. The use of adjusted data from images taken using a stereoscopic loupe is considered a feasible method for color measurement.

Development of whitening mouth rinses formulated with mushroom residues and their effect on enamel's physical properties.

This study aimed to develop whitening mouth rinses formulated with industrial mushrooms and compare them with over-the-counter whitening mouth rinses. Formulations with black shimeji mushrooms, mushroom substrates, and mushroom stalks were developed. Bovine enamel/dentin samples were divided into 7 groups (n = 10): Colgate Luminous White, Listerine Whitening Extreme (LWE), Listerine Cool Mint (LC), mushroom extract rinse (MEC), mushroom substrate rinse (MSB), mushroom stalk rinse (MTC), and artificial saliva. Samples were stained with black tea for 6 days, and then were immersed in 100 mL of each mouth rinse twice daily for 14 days. Color parameters (CIELAB [ΔE*], CIEDE2000 [ΔE00], whiteness index for dentistry [ΔWID]) and microhardness (Knoop hardness number [KHN]) were analyzed at T1 (initial), T2 (24 hours), and T3 (7 days). Mouth rinse pH was measured, and enamel was examined using a scanning electron microscope. Data were analyzed using generalized linear models, and KHN with the generalized linear mixed model for repeated measures (p ≤ 0.05). ΔE* was higher in LW and MSB groups. No significant differences were found for ΔE00 (p = 0.0982) and ΔWID (p = 0.2536). Experimental mouth rinses did not promote enamel whitening based on ΔE00 and ΔWID. LWE and LC reduced KHN and had a more acidic pH, while MEC had higher KHN at T2. MEC, MSB, and MTC had alkaline pH, not altering the tooth surface. Black shimeji mushrooms are promising for mouth rinse development due to their alkaline pH and non-altering effect on surface microhardness.

Effect of layering strategy and prolonged water aging on masking ability of composite resins

Statement of problemLayered composite resins may adequately mask discolored substrates. However, whether color changes that occur over time affect masking ability is unclear. PurposeThe purpose of this in vitro study was to investigate the effect of layering and water aging on the masking ability of 2 composite resins. Material and methodsDisk specimens (1.5 mm-thick and shade A1) from Charisma Diamond (CD) and Filtek Z350XT (Z350) were made according to the composite resin shade combination used in the layering strategies: bilayer for CD (enamel/dentin) and for Z350 (enamel/body and enamel/dentin) and trilayer for Z350 (enamel/body/dentin) (n=5). Color measurements were obtained with a spectrophotometer over an A3.5 ceramic substrate, and the whiteness index for dentistry (WID) was calculated. The specimens were aged in water at 37 °C and evaluated at different times: 24 hours, 1 week, 1 month, 2 months, 6 months, 12 months, 18 months, and 24 months. CIEDE2000 color differences (ΔE00) and WID differences (ΔWID) were calculated and interpreted by 50:50% color and whiteness perceptibility and acceptability thresholds. Changes among strategies and aging times were analyzed using the Kruskal-Wallis test (α=.05). Contrasts were made using the Mann-Whitney U test with Bonferroni correction (α=.001). ResultsΔE00 decreased from 24 hours to 2 months of aging. From 2 months onwards, ΔE00 increased for all layering strategies and times, without significant changes in lightness for CD (P>.004). Overall, for the CD restorative system, an increase in ΔWID was observed after 1 month of aging (P<.001), while for the Z350 restorative system, ΔWID decreased after aging (P<.001), except for the Z350 bilayer strategy (enamel + dentin) at 1 week and 2 months (P>.004). For all layering strategies and aging times, color differences were higher than the 50:50% perceptibility threshold for ΔE00 and, after 6 months, higher than the 50:50% acceptability threshold for ΔE00 and the 50:50% whiteness acceptability threshold. ConclusionsThe ability of the tested composite resins to mask a discolored substrate was affected by the layering approach applied and by prolonged water aging.

The Efficacy of At-home, In-office, and Combined Bleaching Regimens: A Randomized Controlled Clinical Trial

The aim of this study was to compare the clinical efficacy of at-home, in-office, and combined bleaching regimens. Forty-eight participants were recruited and randomly divided into four groups based on the bleaching regimen (n=12) as follows: 1) at-home bleaching using 10% carbamide peroxide (Opalescence PF 10%, Ultradent) for 14 days (HB); 2) two sessions of in-office bleaching using 40% hydrogen peroxide (Opalescence BOOST PF 40%, Ultradent) with a one-week interval (OB); 3) one session of in-office bleaching followed by at-home bleaching for seven days (OHB); and 4) at-home bleaching for seven days followed by one session of in-office bleaching (HOB). Tooth color was measured using a spectrophotometer (Easyshade, Vita ZahnFabrik) at baseline (T0), day 8 (T1), day 15 (T2), and day 43 (T3, four weeks after the end of the bleaching treatment). The color data were calculated using the CIEDE2000 (ΔE00) and whiteness index for dentistry (WID) formulas. Tooth sensitivity (TS) was recorded using a visual analogue scale (VAS) for 16 days. Data were analyzed by one-way analysis of variance (ANOVA) and the Wilcoxon signed-rank test (α=0.05). All bleaching regimens resulted in a significant increase in WID values (all p<0.05), while no significant differences in WID and ΔWID values were found among the different groups at each time point (all p>0.05). Significant differences in ΔE00 values were observed between T1 and T3 for all groups (all p<0.05), while no significant differences in ΔE00 values were found among the different groups at any time point (all p>0.05). Significantly lower TS values were observed in the HB group than in the OB and HOB groups (p=0.006 and p=0.001, respectively). All bleaching regimens resulted in great color improvement, and different regimens led to similar color changes at any of the evaluation time points. The sequence of treatments applying in-office bleaching or at-home bleaching did not affect the bleaching efficacy. The in-office bleaching and combined bleaching regimens yielded a higher intensity of TS than did at-home bleaching.

Tooth color change promoted by different whitening toothpastes under alternate cycles of staining and brushing

ObjectivesTo compare the effect of whitening toothpastes with different mechanisms of action on discolored teeth subjected to additional staining/or not. MethodsOne hundred twenty tooth specimens were stained for 14 days (staining broth under constant agitation and pH=7) and then allocated into the groups of toothpastes with different whitening ingredients (n=10): 1. Regular - Colgate Total 12 Clean Mint; 2. CLWI - Colgate Luminous White Instant (blue pigment); 3. CLWA - Colgate Luminous White Advanced Expert (hydrogen peroxide); 4. CLWAC – Colgate Luminous White Activated Charcoal (activated charcoal); 5. OB3D – Oral-B 3D WHITE Brilliant Fresh (abrasive); 6. TW – Teeth Whitening (charcoal powder). Specimens were submitted to two experimental models: A. Daily staining-toothbrush cycling: staining solution (5min), toothbrushing (45 strokes) and artificial saliva (3h), 2x/day, for 5 days; B. Only toothbrushing (30.000 brushing strokes). Color change was determined with a spectrophotometer (CIEDE2000 and Whiteness Index for Dentistry - WID) and statistically analyzed (α=0.05). ResultsFor both models, ΔE00 and Δa did not differ significantly between the whitening toothpastes and the regular. All groups showed a decrease in tooth yellowness (-Δb) and an increase in WID. Group Teeth Whitening exhibited a decrease in luminosity (-ΔL). In model A, Groups did not differ significantly from the Regular in terms of ΔL (p=0.35) and Δb (p=0.74). Groups CLWI and OB3D exhibited a decrease in luminosity. Reduced redness (-Δa) occurred only in Group CLWI. In Model B, Groups OB3D (p=0.021) and CLWA (p=0.001) exhibited higher change in luminosity than in Group Teeth Whitening. All exhibited increased redness (+Δa) and lightness (+ΔL), except the Regular, CLWAC, and Teeth Whitening. Group OB3D had a significantly higher change in Δb than the Regular (p=0.021). ConclusionsIrrespective of the mechanism of action, all toothpastes reduced tooth yellowness and promoted similar overall color change. Exposure of the teeth to additional staining during the toothbrushing cycles did not influence the effect of the whitening toothpastes. Clinical SignificanceWhitening toothpastes should be tested in conditions that more closely simulate their use in a clinical scenario, in which alternate cycles of staining and brushing occur on a daily basis. However, even in such conditions, they were unable to promote a color change that differed from that of a regular toothpaste.

Background and surrounding colors affect the color blending of a single-shade composite.

This study evaluated the background and effect of surrounding colors on the color blending of a single-shade composite used in a thin layer. Disc-shaped specimens (1.0 mm thickness) were built with the Vittra APS Unique composite surrounded (dual specimens) or not surrounded (simple specimens) by a control composite (shade A1, A2, or A3). Simple specimens were also built with only control composites. The specimen color was measured against white and black backgrounds with a spectrophotometer (CIELAB system). The whiteness index for dentistry (WID) was calculated for simple specimens. Differences (ΔE00) in color and translucency parameters (ΔTP00) between the simple/dual specimens and the controls were calculated. The translucency adjustment potential (TAP) and color adjustment potential (CAP) were estimated based on the ratios between data from simple and dual specimens. The Vittra APS Unique composite showed higher WID values than the controls. No differences between ΔTP00_SIMPLE and ΔTP00_DUAL were observed for any of the shades. The composite shade did not affect TAP values. The lowest values of ΔE00_SIMPLE and ΔE00_DUAL were observed for shade A1 regardless of the background color. For the white background, ΔE00_SIMPLE values did not differ from those of ΔE00_DUAL for all shades. Only A1 showed ΔE00_DUAL values lower than ΔE00_SIMPLE when the black background was used. The highest modulus of CAP (negative values for the white background) was observed when shade A1 surrounded the Vittra APS Unique composite. The color blending ability of the single-shade resin composite used in a thin layer was affected by both the surrounding shade and background color.

Effects of surrounding and underlying shades on the color adjustment potential of a single-shade composite used in a thin layer.

This study aimed to evaluate the surrounding and underlying shades' effect on the color adjustment potential (CAP) of a single-shade composite used in a thin layer. Cylinder specimens (1.0 mm thick) were built with the Vittra APS Unique composite, surrounded (dual specimens) or not (simple specimens) by a control composite (shade A1, A2, or A3). Simple specimens were also built only with the control composites. Each specimen's color was measured against white and black backgrounds or the simple control specimens with a spectrophotometer (CIELAB system). The whiteness index for dentistry (WID) and translucency parameters (TP00) were calculated for simple specimens. Differences (ΔE00) in color between the simple/dual specimens and the controls were calculated. The CAP was calculated based on the ratios between data from simple and dual specimens. The Vittra APS Unique composite showed higher WID and TP00 values than the controls. The highest values of ΔE00 were observed among simple specimens. The color measurements of Vittra APS Unique (simple or dual) against the control specimens presented the lowest color differences. Only surrounding the single-shade composite with a shaded composite barely impacted the ΔE00. The highest CAP values were obtained using a shaded composite under simple or dual specimens. The CAP of Vittra APS Unique was strongly affected by the underlying shade, while surrounding this composite with a shaded one barely affected its color adjustment.

Influence of Different Dye Substances on the Effectiveness of Bleaching and H2O2 Diffusion.

This study aimed to evaluate the influence of different dye substances on the effectiveness of bleaching and hydrogen peroxide diffusion (HO). From 300 central bovine incisors, 160 enamel/dentin disks with similar E* values were selected. The specimens were distributed according to the pigment treatment. Aiming to standardize the chromatic change provided by the different pigments, the specimens from each group remained immersed in the pigment solutions for different times (32 specimens per group): DW - distilled water (Control group); BT - black tea; CO - coffee; SD - cola-based soft drink; and RW - red wine. After pigmentation and chromatic change value analysis, only 10 specimens from each group (n=10) were selected, so the chromatic alteration of all groups was similar (ΔE=8.36±0.5). The samples were subjected to bleaching treatment and diffused peroxide was quantified in a visible ultraviolet light spectrophotometer. Two more bleaching sessions were conducted to evaluate ΔE and the Whiteness Index for Dentistry (ΔWID). Concurrently, solutions were prepared with dye agents, and the same ΔE value was obtained in the teeth (ΔE=8.49±0.5). The solutions received a standardized amount of H2O2, being analyzed by a visible ultraviolet light spectrophotometer. Data analysis comprised variance and Tukey's tests (α=0.05). Higher H2O2 diffusion was observed in pigmented groups when compared with DW (p<0.05). The CO and RW groups had the highest ΔE values (p>0.05), meaning greater difficulty in responding to treatment. In relation to ΔWID, RW bleached less than the other groups after the third bleaching session (p<0.05), resembling only the SD group (p=0.467). However, 21 days after ending the bleaching treatment, only RW and CO had the lowest values (p=0.481). Analysis of the solutions revealed that only RW was altered by the peroxide (p<0.05). In conclusion, teeth pigmented with coffee and, mainly, red wine were more resistant to bleaching treatment, although all pigmentations favored increases in transenamel and transdentinal H2O2 penetration.

Effect of surrounded shade and specimen`s thickness on color adjustment potential of a single-shade composite

This study evaluated the effect of surrounded shade and specimens` thickness on the color adjustment potential (CAP) of a single-shade composite. The composite Vittra APS Unique was surrounded (dual specimens) or not (simple specimens) by a control composite (shade A1, A2, or A3). Simple specimens of the control composite were also confectioned. Opacity and whiteness index for dentistry (WID) were calculated for simple specimens. Color differences between the simple (ΔE*SIMPLE)/ dual specimens (ΔE*DUAL) and the controls were calculated. CAP was calculated based on the ratio between ΔE* SIMPLE and ΔE* DUAL. The tested composite presented lower opacity (53 to 62% vs. 80 to 93%) and higher WID (≈ 42 vs. 18 to 32) than controls. Irrespective of the specimens' thickness (1.0/ 1.5 mm), the lowest values of ΔE* SIMPLE (11.1/ 10.8) and ΔE*DUAL (7.2/ 6.1) were observed using the surrounding shade A1. The shade A3 yielded higher ΔE*SIMPLE (16.4/ 17.1) and ΔE* DUAL (11.3/ 12.3) than the A2 (ΔE*SIMPLE = 13.4/ 14.6; and ΔE* DUAL = 9.7/ 10.3). The specimen`s thickness significantly affected the CAP (0.35 and 0.44 for 1.0 and 1.5 mm, respectively) only for shade A1, which had the highest CAP values. The shade A3 resulted in higher CAP values (0.31) than A2 (0.27) when 1.0-mm thick specimens were used, but similar values were observed for 1.5 thick specimens (≈ 0.29). In conclusion, both surrounding shade and specimen thickness can affect the CAP of a single-shade resin composite.

57 - Can Smoking affect Whiteness and Color Change after At-Home Bleaching?

To evaluate the effect of smoking on tooth whiteness and color change after at-home bleaching. The present investigation is a cohort study with 40 patients (N=40), assigned into 2 groups: NS- non-smokers (n=24) and S- smokers (n=16). At-home bleaching was performed with 22% carbamide peroxide (CP) using individual trays for 1 h a day for 14 days. CIELAB color coordinates were obtained from the six upper anterior teeth (CI- central incisors, LI- lateral Incisors and C- canines) using a Vita Easy Shade spectrophotometer before bleaching (D0-baseline), one day (D1), 15 days (D15) and one month (D30) after the end of the treatment. Whiteness index for dentistry (WID) and CIEDE2000 color difference (ΔE00) were calculated and used to evaluate the bleaching efficacy. Whiteness (ΔWID) and color (ΔE00) changes were compared between NS and S in distinct dental groups using the Mann-Whitney test (α=0.05). The corresponding 50:50% acceptability thresholds were used to analyze the whiteness (WAT) and color (AT) differences obtained in this study. For all teeth groups, NS showed similar median WID values than S at baseline (D0) (p>0.05), but higher values than S for the other evaluation times (D1, D15, and D30) (p≤0.05).For ΔWID values, NS showed greater differences values (D1-D0, D15-D0, and D30-D0) for CI and C when compared to those of S (p≤0.05), and all these differences were above WAT value. In addition, although NS showed higher ΔWID values than S for the period D30-D1 (p≤0.05), both of them were below WAT value. ΔE00 values showed similar behavior than ΔWID for all the groups. Smoking influenced on the whiteness and color alterations, after at-home bleaching treatment using 22% CP. However, the observed whiteness and color alterations were clinically acceptable for smokers.

Clinical evaluation of in-office tooth whitening with violet LED (405 nm): A double-blind randomized controlled clinical trial

Background: Although there is little evidence showing the effectiveness of violet LED on in-office tooth whitening, there are some studies which have reported satisfactory results. This double-blind randomized controlled clinical trial aimed to evaluate the effect of a violet light emission diode (LED) (405 nm) system, used in-office, on tooth whitening, sensitivity, use of medication after whitening and quality of life.Methods: Eight patients were randomized into 4 groups (n = 20): G1 - violet LED, G2 - 35% carbamide peroxide (CP) and violet LED, G3 only CP 35% and G4 35% hydrogen peroxide (HP). The color was measured using a spectrophotometer at the following times: baseline, 15 and 180days. The colorimetric changes were analyzed using measurements from the CieLab System ΔE (ΔL, Δa and Δb) and the WID (Whiteness Index for Dentistry) for the 4 groups. Tooth sensitivity was recorded via a visual analog scale (VAS). Additionally, the Psychosocial Impact of Dental. Aesthetics Questionnaire (PIDAQ) was used to evaluate quality of life.Results: For the analysis of ΔL, G4 and G2 presented more brightness than G1 and G3 (p<0.05), implying that G2 is at least as good as G4 (p>0.05). For measure of Δa, G4 presented better results, standing out from the other groups. (p<0.05). For Δb, both G4 and G2 showed a greater tendency for blue color than groups G1 and G3 (p <0.05). When analyzing ∆E at the 180-day follow up, G4 produced the highest ∆E, while G3 showed the lowest ∆E. The other 2 whitening groups produced intermediate ∆E values. For ∆W, G1 and G3 significantly differed from G2 and G3. When analyzing the 180-day follow up, G2 produced the highest ∆W, while G3 showed the lowest ∆W. The other two whitening treatments produced intermediate ∆W values. As for sensitivity, only G4 patients showed dental sensitivity within 24 h of the bleaching, with pain ceasing after 48 h. For G4, 33% of the patients needed to take analgesics within the first 24 h after the first 3 whitening sessions. For PIDAQ, there was no overall decrease in score over time for any of the groups and there was no difference between them (p>0.05).Conclusion: Our results showed that violet LED was not able to whiten teeth at the same intensity, when used alone, as it was when associated with 35% CP, contrary to our initial hypothesis. However, given that pain was not consistently reported in G2, one could suggest that treatment with LED + 35% CP is quite similar to that of 35% HP when used for tooth whitening, but with better pain outcomes. All treatments suggested an improvement in quality of life.Clinical Trial Registry: This trial is registered at ClinicalTrials.gov; the registration number is NCT03192852 https://clinicaltrials.gov/ct2/show/NCT03192852

Impact of short-term dental dehydration on in-vivo dental color and whiteness

ObjectiveTo determine in-vivo chromatic and whiteness changes produced by short-term dental dehydration. MethodsSpectral reflectance of 452 upper incisors (226 centrals and 226 laterals) of 113 participants were measured using a spectroradiometer at baseline and after short-term dehydration (minutes 2, 4, 6, 8 and 10). CIE L*a*b* color coordinates (L*, a*, b*, C*ab and hab) and whiteness index for dentistry (WID) were calculated. Color differences (ΔE00, ΔEab*) and whiteness differences (ΔWID) were computed and interpreted based on their respective 50:50% perceptibility (PT) and acceptability thresholds (AT). Statistical analysis was performed using the related samples Wilcoxon signed-rank test. ResultsL* showed an increasing trend with dehydration, while a*, b*, C*ab and hab have a decreasing tendency. All chromatic coordinates showed statistically significant differences (p < 0.003) at each interval of dehydration compared with baseline, except a* for all teeth. For ΔE00 and ΔEab* values were higher than PT after 2 min of teeth dehydration and higher than AT after 6 and 8 min, respectively. The percentage of teeth exceeding corresponding PT was higher than 50% after 2 min. WID index increased with dehydration time, while whiteness differences were clinically perceptible after 4 min. Statistically significant differences were found for WID between all dehydration intervals (except 8−10 min). The percentage of teeth exceeding whiteness PT was higher than 50% after 6 min of teeth dehydration. ConclusionsShort-term dental dehydration produces clinically unacceptable changes in tooth color and clinically perceptible increase in tooth whiteness level. Clinical significanceClinical shade matching must be done within the first two minutes of any clinical procedure that requires precise chromatic determination but implies a risk of tooth dehydration.

Stain resistance and surface roughness of CAD/CAM processed hybrid ceramic

AbstractThis study evaluated the stain resistance and surface roughness alteration of a CAD/CAM processed hybrid ceramic. Specimens were fabricated: 30 of resin‐based composite (RBC; Filtek Z350), 30 of ceramic (IPS emax Press) and 60 of hybrid ceramic (Lava Ultimate). Color, translucency (BYK Gardner), whiteness index for dentistry (WID) and surface roughness (Surftest SJ‐201P) measurements were made. Samples were randomly separated into three groups: Coffee staining (3 hours/day), coffee staining + mechanical toothbrushing (3 hours/day‐staining + 40 cycles‐toothbrushing) and storage in distilled water (control), all for 30 days Afterwards, all specimens were polished: RBC (n = 10) with a composite polishing kit (Enhance Dentsply), ceramic (n = 10) with a ceramic one (Eve Diapol), half of the hybrid ceramic (n = 10) with the composite polishing kit and the other half (n = 10) with the ceramic kit. Then, final readouts were obtained. Data was analyzed by two‐way analysis of variance. The hybrid ceramic exhibited intermediate color change after staining (P &lt; .05). The hybrid ceramic presented WID chance similar to ceramic in control group (P &gt; .05). After staining/brushing, the hybrid ceramic polishing with the ceramic kit revealed the greatest translucency change (P &lt; .05). RBC and hybrid ceramic polishing with the resin kit presented similar surface roughness alteration (P &gt; .05), except after staining/brushing (P &lt; .05). Also, ceramic was different from the hybrid ceramic polishing with the ceramic kit (P &lt; .05). The hybrid ceramic showed intermediate staining and roughness compared to the RBC and the ceramic. The ceramic polishing kit was more effective in removing stains from the hybrid ceramic.