Color Stability and Gloss of Esthetic Restorative Materials after Chemical Challenges

Quantification of Color Variation of Various Esthetic Restorative Materials in Pediatric Dentistry

Aim of study

The goal of this paper is to find an association between the staining capacity of dental restorations used in pediatric patients and food items and to develop an optimum model to predict the most informative factor that causes the highest amount of color change through machine learning algorithms.

Background

Color changes in restorative materials occur as a result of intrinsic and extrinsic factors, such as the type of restorative material, food items used, polished status of the material, and time interval.

Materials and methods

This was an "in vitro study" conducted at Aligarh Muslim University, Aligarh, Uttar Pradesh, India. The study included 200 specimens, that is, 40 in each group A (orange juice), group B (Amul Kool Café), group C (Pepsi), group D (Amul Kesar Milk), and group E (artificial saliva). The materials were glass ionomer cement (GIC), resin-modified glass ionomer cement (RMGIC), microhybrid composite resin, and nanohybrid composite resin. These were further divided into polished and unpolished groups. The optimum modeling of the prediction of color change in materials by different effective factors was done by machine learning decision tree. We applied two algorithms: Chi-square automatic interaction detector (CHAID) and classification and regression tree (CART). In prediction modeling in the decision tree by CHAID and CART, color change is taken as the dependent variable, and group (type of restorative material), food items, time interval, and polished status are taken as independent variables.

Results

The various beverages caused significant color variation due to different pigmentation agents. The agent that caused the highest color change was Kool Café. The Kesar Milk had the lowest pigmentation capacity. The greatest color variation was found on Glasionomer FX-II submerged in Pepsi and the least on Ivoclar Te-Econom Plus in Kesar Milk. The mean absolute error for the training dataset in the CART model and CHAID model is 0.379 and 0.332, and for the testing data set, it is 0.398 and 0.333, respectively. Therefore, the prediction of color change by the CHAID model is optimum, and we found that the restorative materials have a maximum predictor importance of 0.86 (86%), time interval 0.07 (7%), food items 0.04 (4%), and polished status has the least importance, that is, 0.03 (3%).

Conclusion

The staining capacity of restorative material highly depends on the material itself, the initial time interval, and least on the food items used.

Clinical significance

The clinical performance of dental restorations could be affected by various beverages consumed by children. This study thus provides important clinical insights into esthetic dentistry by offering valuable information on long-term color stability and the effect of polishing on common esthetic restorative materials used in pediatric dentistry.

How to cite this article

Varshney P, Khan SY, Jindal MK, et al. Quantification of Color Variation of Various Esthetic Restorative Materials in Pediatric Dentistry. Int J Clin Pediatr Dent 2024;17(7):754-765.

Staining and bleaching susceptibility of zirconia-reinforced lithium silicate glass-ceramics with different thicknesses, translucencies, and fabrication methods

STATEMENT OF PROBLEM

The influence of different thicknesses, translucencies, and fabrication methods on the spectrophotometric and topographical properties of zirconia-reinforced lithium silicate glass-ceramics (ZLSs) for dental restorations remains unclear.

PURPOSE

The purpose of this in vitro study was to investigate the effect of thicknesses, translucencies, and fabrication methods on the color stability, translucency parameter, opalescence parameter, whiteness stability, transmitted irradiance, light transmittance, opacity, gloss, and roughness of ZLSs exposed to coffee staining and bleaching treatments.

MATERIAL AND METHODS

Two pressable ZLSs (VITA AMBRIA, VA and Celtra Press, CP) and 2 machinable ZLSs (VITA Suprinity, VS and Celtra Duo, CD) were examined at high translucency (HT) and low translucency (LT) levels in 2 thicknesses (n=160). The specimens were evaluated at baseline, after coffee staining, and after bleaching. The color stability (ΔE2000), translucency parameter (TP), opalescence parameter (OP), whiteness index (WID), and whiteness stability (ΔWID) were measured with a spectrophotometer. Transmitted irradiance (It), light transmission (T), and opacity (O) were obtained from a light-polymerizing unit and a polymerization light collection device. Roughness stability (ΔSa%) was determined with an optical profilometer, and gloss stability (ΔGU%) was recorded with a gloss meter. Data of ΔCIE2000, ΔWID, ΔSa%, and ΔGU% were analyzed by 4-way ANOVA, and data of the TP, OP, WID, It, T, and O were analyzed by repeated 4-way ANOVA (α=.05).

RESULTS

VS-HT exceeded the ΔCIE2000 acceptability threshold after coffee staining and bleaching protocols. Pressable ZLSs exhibited greater color stability than machinable ZLSs. The 1-mm-thick VA, CP, and CD materials exceeded the ΔWID perceptibility threshold after bleaching. The highest TP and OP was displayed by the 1-mm-thick CP after bleaching. ΔGU increased after water storage and decreased after coffee staining and bleaching. ΔSa% significantly increased after bleaching (P<.05).

CONCLUSIONS

The color stability and other spectrophotometric properties of ZLSs depended on material thickness. The effects of ZLS fabrication methods and translucency levels on their measured properties were inconsistent. Subjecting 1-mm-thick ZLS materials to acidic media adversely impacted their stainability and surface texture.

Influence of incorporation of nanostructured silver vanadate decorated with silver nanoparticles on roughness, microhardness, and color change of pit and fissure sealants

Objective

The aim of this study was to evaluate the roughness, hardness, and color change of pit and fissure sealants of two commercial brands (Fluroshield ™ and Ultraseal XT ™) incorporated with nanostructured silver vanadate nanomaterial decorated with silver nanoparticles (β-AgVO3) in concentrations (0% - control, 2.5% and 5%).

Material and methods

Two commercial brands Fluroshield TM and Ultraseal XT ™ were used to make the samples with dimensions of 6 × 6 × 4 mm. The control group was made according to the manufacturer's instructions and in the groups with the addition of β-AgVO3, the nanomaterial was added proportionally by mass at percentages of 2.5% and 5%. Roughness properties were evaluated using a 3D Laser Confocal Microscope (n = 10), Knoop microhardness by Microdurometer (n = 10), and color change by Portable Color Spectrophotometer on the CIEDE2000 system (n = 10). Data were evaluated by one-way ANOVA with Bonferroni adjustment and Tukey's mean comparison test at a 5% significance level.

Results

Ultraseal XT ™ sealant roughness showed a significant difference between concentrations with the highest mean for the 5% group (P = 0.010). Regarding the hardness, both sealants showed no significant difference between the groups. Fluroshield ™ sealant showed a significant difference in ΔE00 between the control-2.5% 24.93 (3.49) and control-5% 28.41 (2.58).

Conclusion

It may be concluded that the incorporation of β-AgVO3 influenced the increase in roughness for Ultraseal XT ™ pit and fissure sealant, did not interfere with the microhardness of both sealants, and promoted a change in the color of Fluroshield ™ sealant within clinically acceptable limits.

The Effect of Different Finishing and Polishing Systems on Surface Properties of New Flowable Bulk-fill Resin Composite

AIM

The purpose of this research was to explore how various finishing and polishing techniques affect the surface roughness (Ra) and gloss of flowable bulk-fill injectable resin composite utilized for posterior teeth restoration, following exposure to a range of food-simulating liquids (FSLs) over three months.

MATERIALS AND METHODS

This study comprised fifty-six disk specimens of G-aenial™ Bulk Injectable flowable resin composite which were created using a Teflon mold (10 × 4 mm). Two techniques of finishing and polishing (F/P) were employed: The two-step 3M™ Sof-Lex™ F/P spiral wheels system and the multiple-step 3M™ Sof-Lex™ XT finishing disks supplemented by the Ultradent Jiffy HiShine polisher cup system. The Ra and gloss of the prepared specimens were measured using an interference microscope system and Horiba gloss checker respectively, immediately post-finishing and polishing and then reassessed after three months in artificial saliva and Coca-Cola.

RESULTS

The two-step system showed a statistically significant difference, exhibiting greater "surface roughness (Ra)" and lower "surface gloss (GU)" mean values compared to the multiple-step system under different storage conditions, particularly after 3 months of storage (p = 0.001).

CONCLUSION

The multiple-step polishing system improved the "Ra" and "GU" of resin composite, suggesting their suitability for posterior resin composite restorations. Acidic media had a deleterious impact on the "Ra" and "GU" of resin composite restoration.

CLINICAL SIGNIFICANCE

The quality of resin composite restorations can be significantly improved with the correct use of finishing and polishing systems, particularly in complex areas of posterior teeth restorations, leading to successful dental procedures.

Effect of Activated Charcoal Toothpaste on Color Stability of Bleached Teeth Immersed in Different Drinks

OBJECTIVE

This study aimed to evaluate the effect of activated charcoal toothpaste on the color stability of teeth subjected to tooth bleaching and pigmenting agents.

METHODS

A total of 120 bovine crowns were randomly divided into 12 groups (n=10) according to two study factors: staining solutions (three levels): saliva (control), coffee, and red wine; and toothpaste (four levels): BPC, Bianco Pro Clinical (Bianco Oral Care) (Control); BIW, Black is White (Curaprox); BCA, Bianco Carbon (Bianco Oral Care); and NAT, Natural Suavetex (Suavetex). The samples were subjected to office bleaching with a 35% hydrogen peroxide-based gel (Whiteness HP Blue, FGM), followed by immersion in the solution for 45 minutes per day and daily toothbrushing for 7 days. The color (ΔE) and luminosity changes (ΔL*) were measured using reflectance spectroscopy (Vita EasyShade). The CIE values (L*, a*, b*) were measured at baseline after bleaching (T0) and immediately after immersion in solution each day (Ti1-Ti7) and after all toothbrushing cycles (Tb1-Tb7). ΔE and ΔL were analyzed using a two-way analysis of variance and Tukey's test (α=0.05). The clinically unacceptable level of ΔE > 3.3 was used to evaluate the color change.

RESULTS

The color change was significantly influenced by the staining solutions and toothpastes (p<0.001). The color change (ΔE) was significantly higher when immersed in wine than in coffee, and lower ΔE values were observed for artificial saliva (control), irrespective of the toothpaste used. In artificial saliva, BPC, BIW, and BCA resulted in significantly lower ΔE values than NAT, which presented a clinically unacceptable level of dental color change (ΔE>3.3). Coffee resulted in a lower (L*) reduction than wine, irrespective of the toothpaste used.

CONCLUSION

Charcoal toothpastes resulted in a color change on the surface of the tooth enamel (ΔE). The bleaching effect of the charcoal toothpastes and control evaluated in this study partially reduced the color changes on the surface of the tooth enamel caused by staining solutions but was unable to reestablish the measured values to the baseline. For teeth immersed in artificial saliva, the color change was not noticeable in BCA, BIW, and control-BPC (ΔE≥3.3), except for NAT, which showed a significant color change.

Whitening Effect of Different Toothpastes on Bovine Dental Enamel: an in situ study

The aim of this in situ study was to evaluate color change, surface roughness, gloss, and microhardness in tooth enamel submitted to whitening and remineralizing toothpastes. Fifteen healthy adults (REBEC - RBR-7p87yr) (with unstimulated salivary flow ≥ 1.5 ml for 5 minutes, pH=7) wore two intraoral devices containing four bovine dental fragments (6 x 6 x 2 mm). Participants were randomly assigned and instructed to toothbrush the devices with the tested toothpastes (30 days): CT: conventional; WT: whitening; WTP: whitening with peroxide, and RT: remineralizing toothpaste. A washout period of 7 days was established. Readouts of color, gloss, surface roughness, and microhardness were performed before and after brushing. The results demonstrated no color, gloss, and microhardness differences (p>0.5). The samples brushed with WTP (0.2(0.7) showed higher surface roughness (p=0.0493) than those with WT (-0.5(1.0). The toothpastes did not alter the properties of the dental enamel, except for the roughness. Toothpaste with an abrasive system based on sodium bicarbonate and silica, and that contains sodium carbonate peroxide increased the surface roughness of the enamel.

Effect of two artificial aging protocols on color and gloss of single-shade versus multi-shade resin composites

The long-term color stability and gloss retention of resin composites are among the crucial factors that affect the clinical longevity of esthetic restorations, especially in anterior teeth. This study evaluated the effect of artificial aging by immersion in different storage media and thermocycling on color and gloss of dental single-shade resin composite (Omnichroma) versus multi-shade one (Filtek Z350XT). One hundred resin-composite disc-shaped specimens were used, 50 from each group, Omnichroma and Filtek Z350XT. Ten specimens from each material acted as control group (incubated in saliva). For each material, 40 specimens were divided according to the artificial-aging protocol (immersion at 37 °C for 12 days or thermocycling for 10,000 cycles) and storage media (tea, red wine). Color and gloss were measured before and after artificial aging. Color difference (∆E₀₀) was compared with perceptibility threshold and acceptability threshold. Data were statistically analyzed; independent t test was used to compare results between two tested materials, while two-way ANOVA was used to compare results among the different immersion media within the same material. Artificial aging (immersion or thermocycling) in tea and red wine led to significant color changes and gloss reduction in both materials (P < 0.05), in contrast to control group. Red wine produced highest color differences. Both dental resin-composites; the single-shade (Omnichroma) and multi-shade (Filtek Z350XT) displayed unacceptable discoloration and gloss reduction after artificial-aging in tea and red-wine by immersion or thermocycling simulating one-year clinical-service.

Evaluation of the Color Stability, Water Sorption, and Solubility of Current Resin Composites

This study aims to assess the color stability, water sorption, and solubility of 11 resin composites as commercially available dental products. Twenty samples (10 mm in diameter and 2 mm in thickness) of each material were fabricated using a customized silicone mold, followed by immersion in each of curry, coffee, wine, and distilled water for 28 days (n = 5). Baseline shade and color changes (ΔE) were measured using a reflection spectrophotometer. The CIE L*, a*, b* system was used to evaluate the color changes. Five samples of each resin composite were applied to test water sorption and solubility according to ISO 4049:2009. As a result, the ∆E values were significantly influenced by each of the three factors (composition of material, solution, time) and the interactions between them (p < 0.001). Highest resistance to discoloration was achieved by Ceram.X One Universal (CXU), followed by Magnafill Putty (MP). Generally, microhybrid composites showed fewer color changes than nanohybrid composites and giomers. DX. Universal and Filtek Z350 XT showed the highest ΔE values in all colorants. All materials tested in this study fulfilled the criteria of ISO 4049:2009; CXU and MP had the lowest water sorption and solubility. The Pearson test showed statistically significant positive correlations between water sorption and ΔE and between solubility and ΔE.

Optical Property Stability of Light-Cured versus Precured CAD-CAM Composites

Objective. The aim of this study was to evaluate the optical property changes after staining of precured (PC) and light-cured (LC) composites. Materials and Methods. Specimens were prepared using different LC composites (GrandioSO—Voco, Filtek Z350-3M/ESPE, Opallis—FGM, and Kalore—GC) and four PC blocks (Grandio Blocs—Voco, Lava Ultimate—3M ESPE, Brava Block—FGM, and Cerasmart—GC) from the same manufacturers (n = 20). Baseline color, gloss, translucency, and fluorescence were evaluated. The staining protocol was performed for 15 days, and the final optical properties were reevaluated. Results. The changes in each property were calculated (ΔGloss, ΔTranslucency, ΔFluorescency, ΔE  $\ast$  00). Data were analyzed by ANOVA and Tukey’s test (α = 5%). Changes in all properties were observed after staining for all materials, with darkening and reduction of gloss, fluorescence, and translucency. Nonsignificant differences were observed between the light-cured and precured materials of the same manufacturer for ΔG and ΔT, but significant differences existed for ΔF and ΔE  $\ast$  00. For ΔF, the only significant differences were observed between Brava Block and Opallis (smaller). For ΔE  $\ast$  00, only the light-cured composites GrandioSO and Z350 showed significantly less change than the corresponding blocks. Precured composites were affected the same way as light-cured ones by the staining in relation to the reduction of gloss and translucency. Conclusion. A higher reduction in fluorescence was observed for only one brand of block and was similar for the others. The two brands of light-cured materials showed less staining, while for the others, the staining was similar. The effects of staining vary according to the composite formulation.

Can Specular Gloss Measurements Predict the Effectiveness of Finishing/Polishing Protocols in Dental Polymers? A Systematic Review and Linear Mixed-effects Prediction Model

PURPOSE

The current gold standard measure to assess polishing efficacy is surface roughness (SR) assessed in laboratory research. Specular gloss (SG) has been negatively correlated to SR, which raises the following question: Can SG be used to accurately determine the effectiveness of a finishing/polishing procedure in direct resin composites?

METHODS

A systematic approach and search strategy, following Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, was developed and conducted in five electronic databases: PubMed/Medline, Scopus, Web of Science, EMBASE (Ovid), and SciELO/LILACS to identify laboratory studies that assessed SR and SG, simultaneously, of resin composites, without date or language restriction. Risk of bias assessment was carried out by two reviewers, independently. From the extracted quantitative data of SG/SR, regression analyses were performed, and a linear mixed-effects prediction model was derived using the nimble package in R (v4.0.3).

RESULTS

A total of 928 potential studies were found, out of which, 13 were eligible after criterion screening. Experimental groups featured 31 resin composites of six different filler types, with the most common being microhybrids followed by nanohybrids. More than half of the studies initially reported a linear correlation between SR and SG, which ranged from r2 = 0.34-0.96. Taking into account the regression analysis and prediction model posteriorly performed, the corresponding SG threshold for 0.2 μm is estimated to be >55 GU. Most of the evidence was classified as moderate or high risk of bias.

CONCLUSION

SG is universally correlated to SR in polymers, and a reference value of >55 GU is proposed, above which samples are considered well polished.

Does polishing of bleached enamel affect roughness and tooth color stability after exposure to coffee?

OBJECTIVE

This laboratory randomized study was designed to evaluate the effect of polishing on roughness and color stability of bleached teeth after coffee immersion.

MATERIALS AND METHODS

Ninety bovine crowns were randomly allocated to six groups (n = 15), according to bleaching protocols: At-home: standard protocol using 10% hydrogen peroxide (HP) or In-office: standard protocol using 35% HP; and with polishing protocols: (1) no polishing, (2) bleached enamel polished with #0.5 μm or (3) #2-4 μm diamond particles grit pastes. Samples were daily immersed into coffee solution for 45 min followed by mechanical brushing simulation (30 s) for 30 days. The surface roughness (Ra) and color alteration, expressed by ΔEab , ΔE00 , and whitening index (WI) were analyzed at baseline, after bleaching/polishing protocols and after coffee solution staining. The surface from each group was examined using a scanning electron microscope. Data were analyzed by two-way repeated measure analysis of variance followed by the Tukey test (α = 0.05).

RESULTS

Staining increases Ra, ΔEab , ΔE00 , and decreases WI values. Polishing after bleaching did not prevent staining, however, tooth polished with #0.5 μ-grit polishing paste showed better performance than #2-4 μ-grit (ΔEab : p = 0.001/ΔE00 : p = 0.003). Scanning electron microscope revealed a more irregular surface after coffee staining for all groups regardless bleaching/polishing protocols.

CONCLUSIONS

Using #0.5 μ-grit diamond paste to polish 35%HP in-office bleached enamel reduces the roughness and tooth staining. However, polishing after 10%HP at-home bleached enamel neither affects roughness nor improves tooth color stability after exposure to coffee.

CLINICAL SIGNIFICANCE

Polishing after at-home bleaching does not have benefits but after 35% hydrogen peroxide in-office bleaching, the polishing with #0.5 μ-grit polishing paste is indicated to reduce roughness and the tooth staining over time.

Comparison of restorative materials and surface alterations after prebiotic and probiotic beverages: A nanoindentation and SEM study

The purpose was to investigate the surface characteristics of various resin-based materials by immersing in probiotic beverages. A total of 420 disc-shaped samples (5 mm × 2 mm) were prepared from resin-based composites. Samples were divided into four groups and immersed for 10 min/day for 1 month in either a probiotic sachet, kefir, kombucha, or artificial saliva (control). Surface roughness was measured at baseline and 1 month. One sample of each of the tested materials was examined under nanoindentation to evaluate the reduced elasticity modulus and nanohardness scores. Scanning electron microscopy (SEM) was used to compare surface differences. Data were analyzed statistically using one-way ANOVA test and the significance was set at p < .05. The lowest roughness scores were observed in Z250, Estelite Bulk Fill, and HRi ENA in most of the test groups. Among conventional composites, Z250 group had the highest nanohardness and elasticity modulus scores. Among bulk-fill composites, Estelite Bulk Fill Flow had the lowest surface roughness after immersion in probiotic beverages and the highest nanohardness values. Reveal HD, as a bulk-fill group showed higher surface roughness and considerably lower nanohardness and elasticity modulus scores. Maximum height levels of samples were recorded. SEM images revealed voids and microcracks on the surfaces of test materials. Dentists may prefer Z250 as microhybrid and Estelite Bulk Fill Flow as bulk-fill composites for the restorations of patients who consume gut-friendly drinks regularly. When there are various types of materials, nanoindentation is a useful method for evaluating surface alterations and sensible comparisons.

Oxygen Inhibition of Surface Composites and Its Correlation with Degree of Conversion and Color Stability

This study investigated the effects of oxygen inhibition and finishing/polishing procedures on the composite resin properties. One bulk-fill and two conventional composite resins (nanoparticle and microhybrid) were evaluated. Specimens were prepared using 4 surface treatments: control, no treatment; Gly, oxygen inhibition with glycerin; FP, finishing and polishing; Gly + FP, glycerin followed by finishing and polishing. The degree of conversion (DC) was measured using Fourier Transformed Infrared Spectroscopy (FTIR) immediately and after 15 days (n=5). Color stability (ΔEab, and ΔE00) and opacity were evaluated using a spectrophotometer after 15 days of immersion in coffee, using the CIELAB system (n=5). Data were analyzed by two-way ANOVA and Tukey tests (α=0.05) and opacity by two-way repeated-measures ANOVA. Glycerin usage increased significantly the DC however had no influence on the ΔEab, ΔE00 and, opacity values. Finishing and polishing reduced ΔEab and ΔE00 values, regardless of composite resins. Microhybrid showed higher opacity, followed by the nanoparticle and bulk fill, regardless of surface treatment. Post-polymerization polishing procedures resulted in lower conversion than using an oxygen inhibitor agent (Gly condition), but similar staining caused by coffee.

Long-term color stability of light-polymerized resin luting agents in different beverages

PURPOSE

The purpose of this study was to evaluate the long-term color stability of light-polymerized resin luting agents stored in different beverages.

METHODS

Eleven shades of two light-polymerized resin luting agents, Choice2 (A1, A2, B1, TRANSLUCENT, MILKY OPAQUE, and MILKY BRIGHT) and BeautiCem Veneer (H-Value, M-Value, L-Value, Ivory-D, Ivory-L) were selected in this study. Disk-shaped specimens were fabricated with 1.3 mm thickness and 15.0 mm diameter. A total of 198 specimens, 18 for each shade, were prepared and randomly divided into six storage conditions (purified water, coffee, cola, tea, red wine, and air). All shades of specimens were three times measured at three random locations (n = 9) at 24 h storage in air after specimen preparation and then measured after immersion at 1, 3, 6, 9, and 12 mos. using a colorimeter. Then, the color difference (ΔE) between the specimens at 24 h after preparation and after storage in each liquid for 12 mos. was calculated. Statistical analysis was performed using Steele-Dwass multiple comparison test of the ΔE values or one-way ANOVA and Tukey's honest significant difference test.

RESULTS

For all immersion conditions, ΔE was significantly higher than air (control). The ΔE of the shades in the various storage conditions showed no significant difference between Purified Water-Cola and Coffee-Tea. Comparisons of the color components L*, a*, and b* for each shade showed different behaviors among the shades.

CONCLUSIONS

The results suggest that the color stability of light-polymerized resin luting agents may differ between different shades and beverages.

Effect of polishing technique and immersion in beverages on color stability of nanoceramic composites

Background

Polishing of dental composite restorations to achieve a highly smooth and reflective surface not only enhances esthetics but also their color stability and improves resistance to staining. The objective of this study was to evaluate the effect of beverages on the color stability of nanoceramic composites polished using different techniques.

Methods

80 samples of ceram. X SphereTEC one were prepared by condensing the material into a stainless-steel split mold and divided randomly into two groups. Group I was subjected to polishing using Sof-Lex system™ disks, and Group II was kept unpolished. Each group was subdivided into four sub-groups of 10 samples each. Each subgroup samples were immersed into designated beverages (Tropicana orange juice, Coco-cola, Nescafe coffee, and distilled water) for a duration of 15mins/day for 15 days. The color of all specimens before immersion, one day, and 15 days after immersion was measured using a Spectrophotometer.

Results

Significant staining of the material was found with cola drinks and coffee compared to orange juice and distilled water. Polished material showed better resistance to staining by various beverages compared to control group.

Conclusion

Nanoceramic composites exhibited superior color stability after polishing with Sof-Lex system™. Among the beverages, coco-cola significantly altered the color of the composite.

Pit and fissure nanocomposite sealants reinforced with organically modified montmorillonite: A study of their mechanical properties, surface roughness and color stability

The aim of the present work was to investigate the effect of the different organically modified nanoclays on clinically significant properties of new synthesized dental pit and fissure nanocomposite sealants. Their morphological characteristics were examined by means of X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). A universal testing machine was used to conduct the flexural and compression tests. Surface roughness measurements were taken by using a 3D-optical profilometer. Color changes after aging in black tea were determined by recording UV-visible spectra. XRD plots depicted possible structures governed by intercalated regions along with some "tactoids" nanoparticles. SEM images revealed a better dispersion for the methacrylated clay nanofiller. Flexural modulus and microhardness were found to be higher for sealants reinforced with such polymerizable nanoclays. These specific nanocomposites yielded smoother surfaces, as well as clinically accepted color changes even after 1 week aging in black tea.

Color stability of Lucirin-photo-activated resin composite after immersion in different staining solutions: a spectrophotometric study

INTRODUCTION

Exceptional optical properties characterize teeth. As such, an esthetic restorative material should enable the dental professional to imitate the optical properties of natural teeth accurately. IPS Empress Direct was introduced to the market with the claim that it can mimic optically dental tissues with superior clinical performance.

AIM

To evaluate the ability of IPS Empress Direct to mimic tooth appearance and color and resist staining.

MATERIALS AND METHODS

Three disc specimens were prepared for each shade of enamel and dentin of Lucirin-based composite, IPS Empress Direct (Ivoclar Vivadent) (A1, A2, A3, B1, and B2) (total of 60). The specimens were submitted to colorimetric evaluation in comparison after immersion in 10 different solutions (coffee, coffee with sugar, coffee with milk, red tea, red tea with sugar, red tea with milk, tomato juice, pomegranate juice, coke, and distilled water as a control group) for 4 weeks using spectrophotometric analysis.

RESULTS

After plotting the data and conducting linear regression analyses, IPS Empress showed high potential in mimicking the optical properties of natural tooth color according to the CIE color space. Three solutions showed a change in color higher than 3, coffee, coffee with sugar, and red tea. All other solution showed changes in color that are acceptable clinically.

CONCLUSION

IPS Empress Direct can satisfactory mimic teeth appearance and color while manifesting high stability of color resisting staining upon clinical aging.