Significant Difference In Color Change Research Articles

Effect of conventional cigarette smoking and recent heated tobacco products on CAD/CAM restorative materials

ObjectiveTo determine the effects of conventional cigarette smoking (CS) and recent heated tobacco products (HTPs) on the surface roughness and color stability of different indirect restorative materials.Materials and methodsOne hundred disc-shaped samples were constructed of three different restorative CAD/CAM materials: lithium disilicate glass–ceramic (IPS e.max CAD; Ivoclar Vivadent, Liechtenstein), zirconia (BruxZir® Zirconia, Glidewell, USA) and polyetheretherketone (BioHPP® bredent GmbH, Germany). Of the IPS e.max CAD and the Bruxzir samples, 20 samples were glazed, and 20 samples were polished, while the BioHPP samples were all polished according to the manufacturer’s instructions.Fifty samples were subjected to conventional cigarette smoking (LM, Philip Morris International Inc., Egypt) (Groups: IPS e.max CAD_Glazed exposed to CS (LD_G_Cig), IPS e.max CAD_Polished exposed to CS (LD_P_Cig), Bruxzir_Glazed exposed to CS (Zr_G_Cig), Bruxzir _Polished exposed to CS (Zr_P_Cig) and BioHPP exposed to CS (PEEK_Cig) and fifty samples were exposed to heated tobacco product smoking (Heets, Russet selection, Philip Morris International Inc., Italy) (Groups: IPS e.max CAD_Glazed exposed to HTP (LD_G_HTP), IPS e.max CAD_Polished exposed to HTP (LD_P_HTP), Bruxzir_Glazed exposed to HTP (Zr_G_HTP), Bruxzir CAD_Polished exposed to HTP (Zr_P_HTP) and BioHPP exposed to HTP (PEEK_HTP).. Six hundred cigarettes/heets representing 30 days of medium smoking behavior (20 cigarettes/day) were used. Before and after exposure to smoke, the surface roughness of all the samples was measured using JITAI8101 surface roughness tester (Beijing Jitai Tech Detection Device Co., Ltd, China, and the color parameters were assessed using VITA Easyshade Advance 4.01 (VITA shade, VITA made, VITA). The data were analyzed using One-way ANOVA, paired sample t-test and independent sample t-test. The significance level was set at α < 0.05.The surface topography was evaluated by scanning electron microscopy (SEM) and analyzed using energy-dispersive X-ray (EDX) spectroscopy to determine changes in the surface chemical composition.ResultsBoth types of smoking caused significant increases in the surface roughness of all the samples. There was a significant difference in color change between CS and HTP for all materials with different surface finish (P < 0.01) and zirconia had the greatest effect on color change (P < 0.001). In contrast, polyetheretherketone (PEEK) “BioHPP” had the least effect (P < 0.001).ConclusionExposure to different types of smoking induce changes in the surface topography and color of different esthetic restorative materials. Compared with HTP, conventional cigarette smoke has a greater effect on the surface roughness and color stability of esthetic restorative materials. The glazed surfaces showed less change in surface topography than did the polished surfaces. Zirconia showed better color stability when compared to polyetheretherketone (PEEK).

Evaluation of hydrogen peroxide permeability, color change, and physical-chemical properties on the in-office dental bleaching with different mixing tip.

This study aims to assess hydrogen peroxide (HP) penetration into the pulp chamber, color change (CC), physical-chemical properties, and material wastage (MW) and material used (MU) in mixing tips when using in-office bleaching gels with two different mixing tips. Forty teeth were divided into five groups (n = 8) based on the bleaching gels used (Pola Office +37.5% [PO+] and Whiteness HP Automixx Plus 35% [AM+]) and the mixing tip types (T-Mixer and Helical). A negative control group was treated with ultra-purified water. HP concentration was measured using UV-Vis, and CC was evaluated with a digital spectrophotometer. Initial concentration, pH, and viscosity were measured through Titration, a Digital pH meter, and Rheometer, respectively. MW and MU were measured using a precise analytical balance. Statistical analysis included two-way ANOVA, Tukey's, and Dunnett's test (α = 0.05). A higher HP concentration was observed with PO+ with the Helical mixing tip in comparison with AM+ (p = 0.01). No significant differences in CC or MU were found for different mixing tips (p = 0.001). The T-mixer mixing tip resulted in significantly less MW (p < 0.00001) and improved mixture homogeneity and viscosity. Utilizing a T-mixer with self-mixing bleaching gels achieves comparable CC while reducing MW. Moreover, it decreases HP penetration when using PO+. For the application of a self-mixing in-office bleaching gel, a T-mixer mixing tip should be recommended, as it reduces the penetration of hydrogen peroxide into the pulp chamber when using PO+, while also minimizing gel wastage.

Comparative Effects of Three Bleaching Techniques on Tooth Discoloration Caused by Tea.

Objectives: This study aimed to investigate the impact of three different bleaching protocols on tooth discoloration caused by tea. Materials and Methods: Forty extracted sound premolars were cleaned, disinfected, and their initial color parameters were measured (T1). The teeth were then immersed in boiled tea solution for 24 hours, and their color was measured again (T2). The samples were divided into four groups of 10 teeth each. Group A was treated with an in-office bleaching gel followed by 30 seconds of light curing. Groups B, C, and D were respectively treated with 0.24M oxalic acid followed by bleaching gel, 5.25% sodium hypochlorite followed by bleaching gel, and a combination of 0.24M oxalic acid, 5.25% sodium hypochlorite, and bleaching gel. The color was measured once more after the interventions (T3). Data were analyzed using two-way repeated measures ANOVA, paired sample t-test, and Tukey's test. Results: The mean color change (∆E2) between T2 and T3 was significantly higher in group D compared to group A (P<0.05). However, there was no significant difference in color change between groups A, B, and C. Additionally, there was no significant difference in color change between groups B, C, and D. The groups also showed significant differences in ∆L (P=0.007), with the only significant difference found between groups B and C (P=0.001). Conclusion: The combined use of sodium hypochlorite and oxalic acid followed by in-office bleaching gel is more effective than bleaching alone in correcting tooth discoloration caused by tea. This protocol can further reduce yellow coloration.

Does the composite attachment of clear aligners compromise the effectiveness of dental bleaching? An in vitro study

This study aimed to evaluate the effectiveness of dental bleaching with hydrogen peroxide 35% on the surface below the attachments. Twenty-four blocks of bovine incisors were equally divided into 2 groups. The control group comprises the enamel surface free of attachments, whereas the attachment group comprises the enamel surface with attachment. Initial staining of samples was performed with black tea for 7 days; then, an attachment was made in the attachment group with Z250 resin and new staining for another 7 days in all samples. After staining, in-office bleaching was performed in both groups, and the attachments from the attachment group were removed. Color reading was performed with a spectrophotometer at all stages: initial (baseline), after 7 days of staining, after 14 days of staining, after immediate bleaching, and after 24 hours of bleaching. The color difference was calculated, and data analysis was performed using the t test for intergroup analysis. The results showed effective bleaching in both groups; however, there was a statistically significant difference in color change between them 24 hours after bleaching. It was concluded that the presence of attachment did not impair the action of the bleaching agent on the tooth surface.

Evaluation of the Effectiveness of Tooth Whitening of Using Reservoir in Bleaching Trays as Compared to Using Bleaching Tray without the Reservoir: An Observational Clinical Trial

Background: Bleaching procedures have gained importance due to the increase in aesthetic demand. At-home bleaching procedures have become popular due to their ease of application at their own time. At-home bleaching procedures can be modified to increase effectiveness. Aim: The present study aims to compare the effectiveness of tooth whitening by using bleaching trays with reservoirs and ones without reservoirs. Materials and Methods: The present study is an observational clinical trial done on 24 patients in Palestine. All the caries-free participants with Canine shades darker than A2 were included in the present study. The sample was divided into two groups. One group received bleaching trays with a reservoir, another group received bleaching trays without a reservoir. 10% carbamide peroxide was used as a bleaching agent in both groups for 21 days with 3-hour wear of trays. The primary outcome measured in the study was color change using the spectrophotometer VITA Easyshade. The secondary outcomes measured in the study were post-bleaching gingival irritation and tooth sensitivity. Statistical analysis was done using SPSS software. T-test was done to compare the primary outcomes between the two groups and the Chi-square test was done to compare the secondary outcomes. Results: T-test showed that there is no significant difference between the color change in the two groups. The chi-square test showed that there is no significant difference in the occurrence of gingival irritation and tooth sensitivity between the two groups (P&gt;0.05). Conclusion: There is no significant difference in color change between the bleaching tray with the reservoir and without the reservoir. There is no significant difference in the increase in gingival irritation or tooth sensitivity between the two groups. Further studies and meta-analyses need to be conducted to obtain more evidence-based data on the outcomes.

In vitro evaluation of dental color stability using various aesthetic restorative materials after immersion in different drinks

BackgroundCurrently, the demands for restorations have increased considerably; thus, improvements and modifications have been made in dental composite technologies especially using materials that have been claimed to improve color stability.ObjectiveThis study aimed to determine the effect of various solutions on the color stability of different restorative materials in vitro study.MethodsThis study used three types of esthetic restorative materials. The samples comprised 45 discs, including 15 micro-hybrids, 15 nano-hybrids, and 15 glass ionomers). These discs were immersed in various beverages an hour a day for one month at room temperature. The color stability was measured using a spectrophotometer before/after immersion (days 7 and 30).ResultsWe realized a significant difference in color change with Coca-Cola and tea-milk solution after seven days and 30 days (p < 0.05). However, no significant difference was found in the samples immersed in DM after seven days and 30 days (p > 0.05). The highest value of lightness (∆L) and stainability (∆a) was seen in micro-hybrid after 30 days of immersion in tea-milk solution (− 12.16 ± 1.74 and 11.4 ± 3.82, respectively), while most samples had a positive ∆b value.ConclusionAfter one month, the tea-milk solution affected the color stability of all used restorative materials. In addition, micro-hybrid had higher color stability than nano-hybrid and glass ionomer.

Effectiveness of resin infiltration (ICON) and microabrasion-remineralization technique with two remineralizing agents (Tooth Mousse and Toothmin) on permanent incisor hypoplasia - A randomized clinical trial.

The study aims to compare the effect of resin infiltration and microabrasion-remineralization (MAb-Re) with Tooth Mousse and Toothmin on permanent incisor hypoplasia. The study included children with permanent incisor hypoplasia above 9 years of age, 171 teeth divided randomly into four groups: Group A - ICON, Group B - MAb-Re using Tooth Mousse, Group C - MAb-Re using Toothmin, and Group D - control group. Process involved taking standardized photographs at T1 - before intervention, T2 - immediately after treatment, and T3 - 6-month follow-up. Color evaluation, area calculation, participant and expert opinion using a Likert scale, treatment time, and cost-effectiveness were all taken into consideration during the assessment. Data were collected, entered into a computer, and analyzed; one-way ANOVA was used for intergroup assessment. Overall color change was evident immediately after treatment in the ICON group compared to other groups (P < 0.05). However, no significant difference in color change was visible between the groups after 6 months. Reduction in hypoplastic area was seen in all the groups. The mean time was similar for all the groups. Toothmin was found to be the most cost-effective in comparison with the other two interventions. ICON proved to be more effective immediately after treatment for masking incisor hypoplasia. However, at 6-month follow-up interval, all the groups gave similar results.

The effect of different herbal teas on the color stability of nanohybrid and bulk-fill composites

Aim: The aim of this study is to investigate the effects of green tea and rosehip tea, on the color stability of nanohybrid and bulk-fill composite resins. Methodology: A total of 60 disc-shaped samples were made from two types of A2 resin with nanohybrid (Tetric N Ceram, Ivoclar Vivadent, Schaan, Liechtenstein) and bulk-fill (Filtek Bulk-Fill, 3M ESPE, MN, USA) structure with the help of 10 mm diameter and 2 mm thick Teflon molds in this study. All samples were finished and polished with 4-stage (thick, medium, fine, superfine) polishing discs (Sof-lex, 3M ESPE, MN, USA) and kept in an oven at 37 °C for 24 hours. The samples, whose initial color measurements were made by spectrophotometer, were divided into subgroups for the control group and two different herbal teas (Green tea, Rosehip) (n=10). Color measurements were repeated, and ΔE values were calculated. Wilcoxon, Kruskal-Wallis, and Bonferroni tests were used to analyze the data (p &lt; 0.05). Results: There was no statistically significant difference in color change between the composite resins (p &gt; 0.05). No significant color change was found for either the Tetric N-Ceram or Filtek Bulk-Fill composite resin samples immersed in distilled water (p &gt; 0.05, ΔE&lt;3.3). Conclusion: Rosehip and green tea affect the color stability of composite resin restorations. Whereas the color change caused by green tea is at a clinically acceptable level, that stemming from rosehip tea falls within clinically unacceptable levels. How to cite this article: Tunçdemir MT, Dereli Z, Bahar A. The effect of different herbal teas on the color stability of nanohybrid and bulk-fill composites. Int Dent Res 2022;12(Suppl.1):103-7. https://doi.org/10.5577/intdentres.445 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Wear and Color Stability of Preheated Bulk-fill and Conventional Resin Composites.

Bulk-fill resin composite is commonly used in direct restorations. It is recommended that the high-viscosity version of these materials be preheated to improve flowability and adaptability. It is unknown what effects preheating (PH) might have on the wear resistance and color stability of these resin composites. This study compared the wear and color stability of high-viscosity bulk-fill and conventional resin composites with and without PH, using the CIEDE2000 formula. Thirty-two disc-shaped specimens (n=16, 10×3 mm) were prepared with Filtek One Bulk Fill Restorative (FOBFR; 3M ESPE) and Filtek Supreme Ultra (FSU, 3M ESPE) to determine wear. Each group was divided into subgroups based on preparation conditions, that is, PH and room temperature (RT) (n=8). Thermomechanical fatigue was applied to specimens, and volumetric material loss was calculated using a laser scanner (LAS-20, SD Mechatronik, Feldkirchen-Westerham, Germany) and three-dimensional imaging software (Geomagic, 3D Systems, Rock Hill, SC, USA). An additional 124 disc-shaped specimens (n=64, 10×1 mm) were prepared with FOBFR and FSU, and subgroups were formed based on preparation conditions (PH and RT, n=32). Specimens were aged for 14 days in coffee, grape juice, distilled water, and thermocycling (20,000 cycles, 5°C-55°C). To determine color change, the lightness (L), chroma (C), and hue (H) values were measured at baseline and after 14 days using the CIEDE2000 formula. All data were statistically analyzed, and a 95% significance level was set. In both the PH and RT groups, FSU exhibited greater wear than FOBFR (p<0.05). Both materials were subjected to increased wear as a result of PH. After aging, a significant difference in color change was observed (p<0.05) when controlling for time and resin composite type, except for deionized water and thermocycling (p>0.05). PH had no effect on the color stability of the resin composite at any time (p<0.05). The high-viscosity bulk-fill resin composite displayed superior wear resistance and similar color stability compared with its conventional counterpart. PH resin composite may increase its susceptibility to wear and has no effect on its color stability.

At-home Bleaching with a Novel Carbamide Peroxide Polymeric Nanoparticle Gel: A Multicenter Randomized Controlled Trial.

To compare the risk and intensity of tooth sensitivity (TS) as well the effectiveness of at-home bleaching using two carbamide peroxide bleaching gels, specifically a novel polymeric nanoparticle gel (experimental) and a commercial gel (Opalescence PF, Ultradent, South Jordan, Utah, USA), applied at two application times. This multicenter, triple-blind, and split-mouth randomized controlled trial was conducted on 80 healthy adults with canine teeth that were shade A2 or darker. The participants all used the experimental and the control gels on one side of a tray, depending on the group to which they were allocated, for 30 or 60 minutes per day over four weeks. The absolute risk and intensity of TS were assessed daily using the five-point Numeric Rating Scale and the 0-10 Visual Analogue Scale. Color change was evaluated with shade guide units (ΔSGU) and a digital spectrophotometer (ΔEab, ΔE00, and ΔWid) at baseline and 30 days postbleaching. The risk and intensity of TS was evaluated by the McNemar and the Wilcoxon signed-rank tests, respectively. Color change (ΔSGU, ΔEab, ΔE00, and ΔWid) was evaluated by Mann-Whitney and paired t-tests (α=0.05). No differences in the risk and intensity of TS were observed based on the bleaching gels used and the times of application (p>0.05). Thirty days after bleaching, there was no significant difference in color change, in terms of the bleaching gels used or the application times (p>0.05). The novel carbamide peroxide polymeric nanoparticles gel, when applied for 30 or 60 minutes, produced effective color change and a low rate of tooth sensitivity, as compared to the control group.

Use of an applicator brush with high concentration bleaching gels.

To evaluate in vitro two high concentration self-mix bleaching gels (35% or 37.5%) with different application tips (with or without an applicator brush) during in-office bleaching. Healthy premolars were randomly assigned to five groups (n = 8): no treatment; 35% HP without applicator brush, 35% HP with applicator brush, 37.5% HP without applicator brush, and 37.5% HP with applicator brush. After the procedures, the concentration of HP transferred into the pulp chamber was evaluated using UV-Vis. The amount of gel used in each group was measured on a precision analytical balance. Color change (ΔEab, ΔE00, and ΔWID) was evaluated with a digital spectrophotometer. Initial concentration was measured by titration with potassium permanganate. The pH was evaluated using a digital pH meter. The data from each test were submitted to nonparametric tests (α = 0.05). Using a tip with an applicator brush expended less gel and left a lower amount of HP inside the pulp chamber compared to the tip without a brush for both bleaching gels (p < 0.0003), although no significant difference in color change was observed (p < 0.05). The 37.5% HP showed a more stable and less acidic pH and a lower amount of HP in the pulp chamber than the 35% HP (p < 0.00001). The HP penetration into the pulp chamber was lower when using an applicator with a brush tip than when using one with a conventional tip. As for the color, both tips were considered to lighten teeth. For the application of a self-mixing high concentration in-office bleaching gel, a brush tip should be recommended because its use diminishes the penetration of HP into the pulp chamber and wastes less bleaching gel.

The Effect of Composite Brushing with Different Types of Toothpaste on Stain Due to Immersion in Coffee, Tea and Cuko Pempek Water

ABSTRACTComposite is a tooth-colored filling material that can change color by extrinsic staining such as coffee, tea and cuko pempek. Abrasive toothpaste can reduce stains but increase surface roughness. This study aims to determine the effect of the type of toothpaste for brushing on the formation of stains caused by coffee, tea and cuko pempek. This research is a quasi-experimental with pre and post control group design. 39 composite discs with a diameter of 1 cm and a thickness of 5 mm were prepared and divided into several groups, 1 group of negative control without treatment, 3 groups of immersion. Each immersion group was divided into 4 brushing groups, namely without brushing, brushing without toothpaste, brushing with abrasive paste and brushing with non-abrasive paste. Pre and post treatment discs were photographed and color changes were assessed using the CIE L*a*b and E system. Friedman, Kruskall Wallis and Mann Whitney U non-parametric analysis test was used to compare color values and color differences within groups and between groups. Based on this study, it can be concluded that there were significant color changes before and after the soaking treatment with coffee, tea and cuko pempek. The color change in coffee was significantly greater than that of tea and cuko pempek. There was no significant difference in color change between tea and cuko pempek. Conclusion: Brushing with toothpaste Keywords: composite; coffee; tea; cuko pempek; CIE LAB

Effect of extraoral aging conditions on the color stability of high temperature vulcanizing and room temperature vulcanizing maxillofacial silicone elastomers: An in vitro study

Maxillofacial prostheses require enhancement or replacement due to deterioration in their color during their use. The major factors that affect the color of the prostheses are ultraviolet (UV) light exposure, temperature changes, and cleaning and handling by the patient. The aim of the study was to find the effect of extraoral aging conditions on the color stability of high temperature vulcanizing (HTV) and room temperature vulcanizing (RTV) maxillofacial silicone elastomers. Specimens of 25mm x3mm dimensions were fabricated in Techsil S25 HTV silicone and Factor II RTV silicones and processed according to the manufacturer’s instructions. Eight groups with eleven specimens each were made. The color stability test was conducted with a Ultraviolet- visible (UV-VIS) spectrometer (Shimadzu) before and after exposure to outdoor weathering and disinfection. The results of the two groups were compared using independent t test. The results of the subgroups were compared with One way ANOVA test followed by Scheffe multiple comparison test. The average color change was found highest in subgroup 4(3.90) and least in subgroup 3(2.3) in HTV samples. The average color change was found highest in subgroup 1(2.70) and least in subgroup 2(1.78) in RTV samples. Color changes caused by HTV samples were significantly greater than that caused by RTV samples. Color changes caused in subgroups 2 and 4 between HTV and RTV samples were significantly greater than in the other groups. There were no significant differences in color change in other subgroups.

Effects of Microabrasion Prior to In-office Bleaching on Hydrogen Peroxide Permeability, Color Change, and Enamel Morphology.

This study evaluated hydrogen peroxide (HP) diffusion within the pulp chamber, as well as color change and the surface morphology of teeth subjected to various microabrasion (MA) protocols associated or not with in-office (IO) bleaching. Forty sound premolars were randomly divided into the following four groups (n=10): no treatment (NC); IO bleaching only; IO immediately after MA (IMA), and IO seven days after MA (7MA). After treatments, the HP concentration (μg/mL) within the pulp chamber was determined using ultraviolet-visible (UV-Vis) spectrophotometry. The color change (ΔE*) was evaluated using the digital spectrophotometer before and 1 week after bleaching. The surface morphology was evaluated by scanning electron microscope (SEM). Data from each test were submitted to one-way ANOVA and Tukey tests (α=0.05). All experimental groups exhibited higher HP concentrations compared to the NC group (p<0.00001). However, higher amounts of HP were observed for the IMA group compared to the IO and 7MA groups (p<0.00001). No significant difference in color change was observed among the groups (p<0.001). Pronounced grooves in enamel were found in the IMA and 7MA groups. However, enamel erosion areas were observed only in the 7MA group. The association between MA and IO bleaching could significantly affect the amount of HP inside the pulp chamber. Therefore, it is highly recommended to wait for 1 week after MA procedures before performing IO bleaching.

Comparison Between Color Stability and post bleaching hypersensitivity of Different Bleaching Protocols – Randomized single-blinded Controlled Clinical Trial

Objective: The aim of the study was to investigate color change, color stability and post bleaching hypersensitivity after performing 3 bleaching protocols, (LASER-activated, light-activated and chemically-activated) at different time intervals. Methods: Patients were randomly assigned into three treatment groups (n=13). Group A received laser bleaching (J.W. Power Bleaching NEXT, 35 % hydrogen peroxide), group B received light-activated bleaching (Philips ZOOM, 25% hydrogen peroxide), and group C received chemical activated bleaching Dash Philips, 30% hydrogen peroxide). Each group received the treatment according to the manufacturer’s recommendations, followed by the desensitizing agent of each kit. Outcome assessment was performed for teeth shade and post bleaching hypersensitivity preoperatively, immediate, three months, and six months post-operatively using a spectrophotometer (Vita Easyshade, Vivadent, Germany). Results: The study showed that there was no significant difference in color change between the three tested groups. LASER-activated bleaching protocol showed no significant difference in median ∆E throughout the study. Light activated bleaching showed decrease in median ∆E three to six months while in chemical-activated bleaching from zero to three months. Post-bleaching hypersensitivity, results showed no significant difference between the three tested groups. Conclusion: All three bleaching methods can be used upon individual’s preference. LASER-activated bleaching group showed superior color stability over time. It can be satisfactory for patients seeking good results with reduced chair time. Keywords: bleaching, post bleaching hypersensitivity, laser, color stability

Colour stability of resin infiltrated white spot lesion after exposure to stain-causing drinks

BackgroundThe resin-based materials are used extensively in esthetic restorations but are.prone to color changes over time. AimsTo assess the discoloration effect of red tea, Arabic coffee, and black coffee on the resin infiltrated white spot lesions (WSL). Moreover, to investigate the impact of time (1d, 3d, and 7d) on the discoloration of the resin infiltrated WSLs. Materials and methodsThirty-three extracted human premolar teeth were used to create WSLs, and ICON resin infiltration treatment was performed to obliterate the enamel pores. Teeth with resin infiltrated WSLs were sectioned into two halves by cutting mesio-distally and cross-sectionally at 1 mm below the CEJ. The resin infiltrated specimens was exposed to control (artificial saliva) and staining subgroups. Colour stability was assessed using the CIE L*a*b* system. ResultsAnalysis of variance (p < 0.05) and Tukey’s multiple comparison tests revealed an insignificant color change in the control group. The immersion of resin infiltrated specimens at time intervals of 1 d (p < 0.001), 3 d (p < 0.001), and 7 d (p < 0.001) showed significant differences in color change. ConclusionResin infiltrated WSLs showed marked color changes after exposure to red tea, black coffee, and Arabic coffee over time. Severe discoloration of the infiltrant was evident with the use of red tea compared to black coffee and Arabic coffee. This suggests that ICON resin-based composite material might not be a suitable material for WSL infiltration.

Spectrophotometric evaluation of the effectiveness of Er,Cr:YSGG laser-assisted intracoronal tooth bleaching treatment using different power settings

BackgroundNon-vital tooth discoloration is a common condition in dental practice. The aim of this in vitro study was to evaluate the efficacy of intracoronal bleaching treatments of non-vital teeth either activated or not by Er,Cr:YSGG laser (2780 nm) operating at 1.25 or 2.5 W. MethodsTwenty four human canines were artificially stained after implementation of root canal treatment. Subsequently, the teeth were randomly divided into three groups (n = 8): Group 1 (control) received intracoronal bleaching treatment with a bleaching gel containing 35 % hydrogen peroxide for 40 min, Group 2 received the same treatment assisted with Er,Cr:YSGG laser (2780 nm) operating at 1.25 W average power for 30 s and Group 3 received the same treatment with Group 2, but the average power was adjusted to 2.5 W. The bleaching treatments repeated after one week. Spectrophotometric analysis of tooth color change (ΔE) was implemented 7 days after both bleaching sessions. ResultsThe results of two-way ANOVA revealed that there was a tendency of no significant difference in color change between the three experimental groups (p = 0.063). However, the between-group comparisons showed that laser 2.5 W group had significantly higher ΔE than the control group after the first bleaching session. Moreover, a significant interaction between bleaching treatment and number of applications was detected (p = 0.026). ConclusionsEr,Cr:YSGG laser irradiation significantly increased ΔE only after the first bleaching session when operating at 2.5 W. After the second bleaching session ΔE was not different compared to the control group, irrespectively of the laser power settings.

Effect of different types of acid-etching agents and adhesives on enamel discoloration during orthodontic treatment.

Background. Acid etching and bonding is a routine process in orthodontic treatment. The present study aimed to evaluate enamel discoloration after using different types of acid etching and adhesive agents. Methods. A total of 105 extracted human premolars were divided into six groups regarding the type of acid etching agent: solution and gel of 37% phosphoric acid, and type of self-cured adhesive agent: Unite (3M, fluoride-free), Resilience (Ortho Technology), and Rely-a-Bond (Reliance, fluoride-releasing adhesive), with each group containing 15 specimens. All the selected teeth were subjected to a staining process, and color parameters were determined using a spectrophotometer. Results. The type of phosphoric acid (solution or gel) had no significant effect on the color change of enamel (P >0.05). Resilience significantly changed the enamel color compared to the Unite and Rely-a-Bond (P <0.001). There was no significant difference in color change between the Unite and Rely-a-Bond adhesives (P =0.67). The difference in color change between all the three time intervals (T0-T1, T1-T2, and T0-T2) was significant (P <0.001). Conclusion. In this study, the type of phosphoric acid (solution or gel) did not result in any significant difference in enamel color. Also, considering the lack of the effect of the orthodontic adhesive type in terms of fluoride release or no fluoride release, it can be concluded that this is most affected by the commercial brand of adhesives.

EFFECT OF REPRESSING ON THE COLOR AND TRANSLUENCY OF LITHIUM DISILICATE PRESSABLE CERAMIC MATERIAL

as chemical composition and thickness. In clinical practice, pressable ceramics were found to be frequently subjected to repressing. Nonetheless, the effect of the repressing on the color stability and translucency have been unknown.OBJECTIVES: The aim of this study was to investigate the effect of repressing on the color and translucency of a lithium disilicate pressable ceramic material (e.max press).MATERIALS AND METHODS: twenty-four disc-shaped ceramic specimens (IPS e.max press ingots) 14 mm in diameter and 1.5 mm thick were divided into two parallel groups: press group and repress group. Each group had 12 specimens. Pressing was performed for e.max press ingots. Repressing was performed using the remaining material resulting from the pressing procedure. Color difference and translucency were measured using a portable spectrophotometer (VITA easy shade Advance). Translucency parameter (TP) was measured on black and white backgrounds. The resultant data were analyzed statistically using Kruskal-Wallis non-parametric test.RESULTS: There was a statistically significant difference in color change after repressing. (p=0.005). e.max pressed group produced color difference (ΔE) values of (3.88±1.12). This (ΔE) values was more than the selected clinical perceptible threshold selected for this study (ΔE=2.6). Moreover, e.max pressed group showed statistically significant decrease in translucency after repressing (p=0.002).CONCLUSIONS: The color of e.max press was affected by repressing with statistically significant decrease in translucency.

The color improvement of postdebonding white spot lesions after fluoride and casein phosphopeptide- amorphous calcium phosphate application.

White spots are common side effects of orthodontic treatment, and their presence after debonding appears unesthetic. This study aimed to quantify and compare the visual improvement in postdebonding white spot lesions following fluoride and casein phosphopeptide–amorphous calcium phosphate (CPP–ACP) application. The sample included 42 upper premolars extracted for orthodontic reasons. Universal premolar brackets were bonded to the facial surfaces of the teeth that were exposed to a demineralization solution to create artificial white spot lesions, after which the brackets were debonded. The specimens were randomly allocated to three treatment groups (n = 14, each): acidulated phosphate fluoride (APF) gel application group; CPP–ACP paste application group; and control group. pH cycling was conducted to all groups for 14 days. Quantitative measurements were carried out using a spectrophotometer at the following times: before and after the white spot lesions artificially formed and after treating them. All groups showed significant differences in color change before and after treatment. However, there was no significant difference in the color improvement between the APF gel and CPP–ACP paste application groups. Although CPP–ACP application improved the color of the white spot lesions, it did not differ significantly from that of fluoride application.