Universal Resin Composite Research Articles

Evaluation of Colour Changes in Nanocomposite-Based Bulk-Fill and Universal Composite Using Different Polishing Systems.

Resins composites are widely used in modern dentistry because of their aesthetic and physical properties. However, discoloration of anterior tooth restorations is a common complaint. Understanding the factors affecting the colour stability of resin composites can lead to longer-lasting repairs. This study aimed to evaluate and compare the colour changes of nanocomposite-based bulk-fill and universal resin composites after immersion in coffee using various polishing systems. A total of 160 samples were prepared using four different composite groups, with 40 pieces for each combined group. Based on the finishing procedure, the samples were divided into four subgroups for each composite group. Three different polishing procedures were applied to the samples according to the manufacturer's instructions. The control group was not subjected to any treatment. Initial colour measurements were performed using a VITA Easyshade V spectrophotometer. After the initial measurements, the samples were immersed in a Nescafe coffee solution for seven days, followed by colour measurements. Data were analysed using the Kolmogorov-Smirnov test and two-way analysis of variance. Tukey's honest significant difference (HSD) test was used to determine differences between subgroups. The results indicate that bulk-fill resins exhibit more discolouration than universal composites; however, this difference was not statistically significant. The resin group with the smallest discolouration was Ceram X, and the most effective polishing method was Twist polishing. Final surface polishing significantly reduced the composites' discolouration. These findings support the selection of appropriate materials and polishing techniques to achieve aesthetic outcomes and colour stability in dental restorations.

Do effervescent vitamin tablets affect the surface roughness, microhardness, and color of human enamel and contemporary composite resins?

To compare the impact of four effervescent vitamin tablets on the surface roughness, microhardness, and color of human enamel and contemporary composite resins. Sixty enamel and a total of 240 anterior (Gradia Direct Anterior), posterior (Gradia Direct Posterior), and universal composite resin (Filtek Ultimate) specimens (n = 60 per group) were fabricated. Each group was subdivided into five subgroups (n = 12, per subgroup). The specimens were subsequently immersed in YOUPLUS,Redoxon, Sunlife Immuvit, and Sambucol effervescent vitamin solutions for 2 min per day over 30 days. Distilled water was used as control. Subsequently, surface roughness (Ra) was detected using a profilometer, and microhardness (VHN) was measured using a microhardness tester. A spectrophotometer device was used to record the L,a,b color coordinates of the specimens after 24 h, 7 days, and 30 days, and the color changes (ΔE00) of the groups were calculated. The data were analyzed by ANOVA, two-way ANOVA, Kruskal-Wallis, Levene's, and Fisher's least significant difference (LSD) tests (p<0.05). SEM analysis was conducted on one randomly selected specimen per group (×1000). In terms of surface roughness, materialXvitamin interactions were found significant (p<0.05). The increase in Ra from 24 h to 30 days was found significant (p<0.05) except for Gradia Direct Anterior X Redoxon, Sunlife Immuvit and Sambucol, Filtek Ultimate X Sunlife Immuvit and Sambucol, and all control groups. Ra changes were also concluded by SEM. Regarding VHNs, material X vitamin interactions were significant (p<0.005), except for all Filtek Ultimate subgroups. The changes in VHNs of the groups from 24 h to 30 days were significant for all enamel and Gradia Direct Anterior X YOUPLUS, Gradia Posterior X YOUPLUS, Sunlife Immuvit, and Sambucol groups (p < 0.05). In terms of ΔE00, significant differences were observed between the 7 days and 30 days in the enamel (p = 0.047), Gradia Direct Anterior (p = 0.019), and Gradia Direct Posterior groups (p = 0.038). Daily consumption of effervescent vitamin tablets can increase surface roughness, decrease microhardness, and influence the color of human enamel and contemporary anterior, posterior, and universal composite resins after a 30-day period.

The effect of detox solution on color stability, roughness, and microhardness of monochromatic universal composite resins

BackgroundCurrently, the advantages of monochromatic universal composite resin restorative materials have increased their use in dentistry. Accordingly, the optical, surface and mechanical properties of these materials have become more important. This study aimed to evaluate the effect of detox solution on discoloration, surface roughness (SR), and microhardness of different monochromatic universal composite resins (Omnichroma [O], Zenchroma [Z], Vittra [V], and Charisma Diamond One [CDO]). Another aim of this study was to evaluate the monomer conversion degree (DC) of the materials.MethodsA total of 80 specimens were prepared to evaluate the materials (n = 10). After the initial measurements, the specimens were immersed in a red detox solution for 21 days. Statistical data analysis was performed using one-way ANOVA and Tukey’s multiple comparisons.ResultsThe ∆E values of Z were highest on the 21st day. There was an increase in the SR values of the materials immersed in the detox solution. On the 21st day, top surface microhardness of O was lower than the other materials. There was no statistically significant difference at DC values among material groups.ConclusionsThe use of detox solutions for a commercially recommended period of 21 days is suggested. However, this usage period can cause discoloration in restorative materials. Furthermore, especially in the initial one-week period, detox solution may have a negative impact on the microhardness of the materials. In light of all these data, we recommend the cautious use of detox solutions to prevent adverse effects on restorative materials.

The Influence of Modeling Liquid on Microhardness of Single-Shade Composite Resins: An In-Vitro Study.

To assess the effect of modeling liquid on the microhardness of single-shade universal composites. A total of 60 disk-shaped samples were prepared in six groups [Omnichroma (OM), Essentia Universal (EU), Vittra APS Unique (VA), OM + Signum, EU + Signum, and VA + Signum] for surface microhardness measurements. Samples were stored in a coffee solution for 7 days and after that bleached with an Office bleaching agent (Total Blanc Office). Surface microhardness was measured for baseline, after staining, and after bleaching. A two-way analysis of variance test was used for statistical analysis (P < 0.05). In terms of microhardness, there is a statistically significant difference (P < 0.05) between the two categories with and without modeling liquid. The alterations in microhardness measurements at baseline, after staining, and after bleaching are statistically significant (P < 0.05). The Essentia groups showed the lowest microhardness findings at all measurement times. Microhardness values decreased significantly more when EU was applied along with modeling liquid than when it was not applied at different intervals. Modeling liquid affects the microhardness of single-shade composites. Microhardness is reduced when modeling liquid is used for all three single-shade universal composite resins at three different times.

The Effect Of Mouthwashes On Color Change In Universal Composite Resin

Background: The use of mouthwash has increased and become a habit since the Covid-19 pandemic. The use of mouthwash is recommended for prevention. The mouthwashes that American Dental Association (ADA) and Center for Disease Control and Prevention (CDC) recommended are chlorhexidine gluconate (CHX), hydrogen peroxide (H2O2), cetilpyridinium chloride (CPC), povidone iodine (PVP-I), dan chlorine dioxide (ClO₂). Universal composite resin is used for every tooth color requirement and has a chameleon effect that can disguise, eliminate, minimize, and neutralize mismatched colors. This study aims to determine various mouthwashes’ effects on the discoloration of universal composite resin. Method: This research is an experimental laboratory by comparing the color changes before and after treatment. Thirty samples of universal composite resin with a width of 10 mm and a height of 2 mm were divided into 5 mouthwash test groups and 1 control group. Color test using a Vita Easy Shade V spectrophotometer and the data were shown in DE assessment. Result: Data were analyzed with One Way ANOVA on DE assessment with the significance level p0.05 on 5 test groups. Conclusion: The 5 groups of mouthwashes showed there was a color change in the DE assessment of universal composite resin

Optical behavior and marginal discoloration of a single shade resin composite with a chameleon effect: a randomized controlled clinical trial

Objective/aimEvaluating the optical behavior and marginal discoloration of a Single-shade universal resin composite over 12 months. To achieve this, a split-mouth with a double-blinded randomized strategy was employed.Materials and methodsTwenty adult patients, each presenting with at least two caries lesions in their posterior teeth, were selected and randomly subdivided into two identical groups: Group I received Single-shade universal resin composite (Omnichroma), and Group II received multi-shade nanohybrid resin composite (Tetric®N-Ceram). Color measurements and marginal discoloration were assessed visually by three blinded operators at baseline followed after 1,3,6,9, and 12‑month periods utilizing the Modified United States Public Health Services (USPHS) criteria. Statistical analysis was adopted utilizing the Wilcoxon test with a 0.05 significance level.ResultsThe two groups revealed non-statistically significant differences up to 6 months regarding color match and color stability. After 9 and 12 months, the multi-shade group demonstrated a statistically significant higher prevalence of color match (Alpha) scores than the single-shade universal group. Regarding marginal discoloration, all restorations in the two groups had no discoloration (Alpha scores).Discussion/conclusionSince the percentage of Alpha and Bravo scores was considered clinical success, both the single-shade universal and the multi-shade nanohybrid resin composites demonstrated satisfactory optical performance and marginal discoloration as posterior restorations after a 12-month follow-up period.

In vitro comparative evaluation of antioxidative effect of selenium alone and in combination with green tea and alpha-tocopherol on the shear bond strength of universal composite resin to enamel after in-office bleaching.

Antioxidant application soon after bleaching process increases the shear bond strength (SBS) of composite resin to enamel. The aim of the study was to evaluate the antioxidant effects of selenium alone and in combination with alpha-tocopherol (αT) and green tea (GT) on SBS of composite resin to enamel following in-office bleaching with 38% hydrogen peroxide (HP). Sixty extracted human single -rooted premolar teeth were cleaned and embedded in acrylic resin blocks at the level of cementoenamel junction(CEJ) followed by bleaching with 38% hydrogen peroxide (HP) and arbitrarily divided into seven groups (n=10) for antioxidant application: Group I (negative control): intact teeth, Group II (positive control): only bleaching, Group III: 10% selenium (Se), Group IV: 10% alpha tocopherol (αT), Group V: 10% αT +10% Se, Group VI: 10% Green tea (GT), Group VII: 10%GT+10% Se. In all groups, self-etch adhesive was applied and composite restoration was done, and specimens were stored in distilled water for 24h followed by SBS evaluation. One-way analysis of variance and post hoc Tukey's tests were used (P < 0.05). The highest SBS was found in negative control Group I (intact teeth) and least in positive control Group II (bleached teeth), whereas in experimental groups, Group VII (GT + Se) showed highest followed by Groups V (αT + Se), III (Se), and VI (GT) and least in Group IV (αT). Combination of selenium with green tea and alpha tocopherol enhanced the SBS of composite resin following in-office bleaching.

The Effect of Modeling Liquid on Color Stability and Surface Roughness of Single-Shade Composites: A SEM Study

The aim of this study; to evaluate the effects of modeling liquid use on the surface roughness and color change of single-shade universal composite resins. Total 174-cylinder shaped samples (60 roughness, 54 FE-SEM analysis, 60 color measurements) were prepared in 6 groups, (n=10) 3 of only composites, 3 of composites and modeling liquid. Composite samples were stored in coffee for 7 days and then bleached with 35% Total Blanc Office. FE-SEM analysis, color changes and roughness were measured. For statistical analysis, Two-way Anova test were used (p&lt;0,05). There is a statistically significant difference between the groups with and without modeling liquid in terms of roughness and color changes (p&lt;0,05). The highest roughness and color changes findings were observed in Essentia groups for all measurement times. When Essentia modeling is applied with liquid, the decrease in roughness and color changes is insignificant at the baseline, but the decrease is statistically significant after staining and after bleaching. FE-SEM findings show surface changes in single-shade composites after staining and bleaching. The use of modeling liquids affects the surface roughness of single-shade composites. It is also seen that the modeling liquid used on the surface of the composites protects the surface.

THow the Translucency and Color Stability of Single-Shade Universal Resin Composites Are Affected by Coffee?

Objective: The aim of this study was to examine how staining with coffee affects single-shade universal resin composites and a multi shade universal resin composite in terms of translucency and color stability. Method: Five different resin composites (Omnichroma, Vittra APS Unique, Zenchroma, Charisma Diamond One, and Neo Spectra ST) were used to create 50 samples (n=10). A spectrophotometer was used to record translucency parameter (TP00) and color changes ( ΔE00) at baseline and after immersion in coffee for 24 h. Color differences were calculated according to CIEDE2000. Data analysis was performed using one-way ANOVA and the paired-samples t-test. Results: After immersion of resin composite samples in coffee for 24 h the Vittra APS Unique group showed the highest ΔE00 value and the Neo Spectra ST group the lowest (P

Degree of cure of orthodontic composite attachments underneath aligners.

The aim of this study was to assess the percentage degree of cure (DC%) of 2-mm-thick resin composite attachments used for aligner treatment. Three types of aligner - two thermoformed aligners (Clear Aligner [CLA], polyethylene terephthalate glycol modified; and Invisalign [INV], polyester urethane) and a three-dimensional-printed aligner (Graphy TC-85DAC [GRP], an acrylate-methacrylate copolymer) - were selected, along with two universal resin composites (3M Filtek Universal [FTU] and Charisma Topaz ONE [CTO]). Samples of each composite were placed under each aligner, and the degree of cure of each composite was evaluated on the top (facing the aligner) and the bottom (facing the substrate) attachment surfaces after curing. Five specimens were used per combination of aligner and composite, and an additional group of composites irradiated without aligners served as the control. The DC% measurements were performed using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The DC% across the aligners were (median values) 33.8%-44.8% for CLA, 33.6%-40.8% for INV, 32.8%-40.6% for GRP, and 40.0%-51.7% for the control group. The DC% values of the attachments cured under any aligner were significantly lower than that of the corresponding control, with the values recorded on the top surfaces being 6% higher than those on the bottom surfaces after adjusting for aligner group and composite type.

A comparison of the effects of incremental and snowplow techniques on the mechanical properties of composite restorations.

Glass fibre-reinforced composite (GFRC) has the potential to enhance the mechanical properties of resin-based restorations. Nevertheless, the application technique can influence the cervical margin porosity, potentially reducing the mechanical strength of restorations. In an in vitro setup, mould specimens underwent six different treatments to assess the effects of snowplow and incremental curing techniques on the properties of GFRC (EverX) and universal resin composite (Filtek). Mechanical properties, namely flexural strength (FS), compressive strength (CS) and Vickers hardness (VH), were evaluated following ISO 4049 standards. Data interpretation utilized the Kruskal-Wallis tests. No significant difference emerged across groups for FS. CS in the snowplow method with lesser EverX thickness (SnPl_1) was comparable with only EverX and Filtek (P > 0.05). The CS was reduced in the snowplow technique with greater EverX thickness (SnPl_2) (P < 0.05) and further decreased with the incremental method (P < 0.001). VH results showed that EverX Posterior was consistently softer than Filtek, with specific patterns of hardness variations among different application methods. Applying EverX and Filtek using the snowplow technique delivers superior CS and VH for restorations in contrast to the incremental method. Utilizing the snowplow approach in high-stress areas can make restorations more fracture-resistant.

Influence of surface roughness of universal shade resin composites on color adjustment potential.

This study aimed to determine the influence of surface roughness of the color adjustment potential restoration of universal resin composites. A structural colored resin composite (Omnichroma, OC) and a pigment-employed universal shade resin composite (Beautifil Unishade, BU) were used. Each resin composite was placed in a cavity to determine its ability to match the color of artificial teeth. The surface of the resin composites was polished with #800- or #2000-grit SiC paper before performing color measurements. One-way analysis of variance and Tukey post hoc tests were performed (α=0.05). The color difference (ΔE*ab) ranged from 2.5-3.9 for OC and 1.8-8.7 for BU. OC has a more stable color adjustment than BU. The color adjustment potential of universal resin composites was affected by the surface roughness of the restorations.

Effect of Coffee and Polishing Systems on the Color Change of a Conventional Resin Composite Repaired by Universal Resin Composites: An In Vitro Study.

The purpose of this study was to evaluate the color stability of repaired aesthetic restorative resin matrix materials after immersion in coffee and the effect of polishing systems after staining. One hundred and eighty cylindrical discs (8 mm × 2 mm) were prepared using a conventional nano-fill resin composite (Clearfil Majesty Esthetic A2 shade) with round cavities (3 × 1 mm). Cavities were repaired by three resin composite materials: Clearfil Majesty Esthetic A2 shade, one-shaded nano-fill resin composite (Omnichroma) and group-shaded nano-hybrid resin composite (Optishade, medium shade). Each group was polished with three polishing systems (n = 20); aluminum oxide (Soflex Spiral Wheels, 3M ESPE), silicon carbide (Occlubrush, Kerr, CA, USA) and diamond particulate (Twist Dia Spiral Wheels, Kuraray, Okayama, Japan). Color change (ΔE00) measurements were performed with a spectrophotometer at the baseline. Half of the polished samples were either kept in distilled water or immersed in coffee for 15 days, and color measurements were repeated before and after polishing. Statistical analysis was performed using the Kruskal-Wallis test. Repaired samples showed different color correspondence values in all groups. All three restorative materials showed significant color changes (ΔE00) after immersion in coffee (p ≤ 0.05). Repolishing of stained samples showed color improvement values in all groups. The content of the polishing system played an important role in removing the stains.

Determining Artificial Ageing Methods and Evaluating Properties of Universal Composite Resin: A Review and Proposed Protocol

Objective: Our aim is to propose a method for determining a more convenient artificial ageing (AA) protocol, which may be used to compare the optical / mechanical properties of universal to conventional composite. Methods: Artificial ageing (AA) protocol was adapted from (Alp et al., 2018) for thermocycling and (Jasin et al., 2018) for static immersion, which arbitrarily simulating 6 and 7 months of oral environment, respectively. In phase 1, Filtek Z350XT® will be used to be immersed in coffee solution (test group) with distilled (control group) water. Colour changes will be measured and calculated using the CIEDE2000 formula and data will be statistically analysed to determine a meeting time point of colour change occurrence. Measurement will be repeated thrice to validate the new static emersion method. In phase 2, this new static immersion AA protocol will be used to compare Omnichroma's® colour stability with translucency to the Filtek Z350XT®. In phase 3, SEM EDS will be used to measure quantitative and qualitatively the occurrence of subsurface properties changes in Omnichroma® and Filtek Z350XT®. Finally, the discs’ microhardness will be evaluated. Significance: Presently, it is very difficult to precisely simulate the oral environment. In comparison to thermocycling, static immersion is a more convenient AA method. Establishing an evidence-based protocol may well potentially serve as a guide for researchers to assuredly select the more simplified AA protocol for future dental material development and clinical usage scenarios.

Surface Gloss, Radiopacity and Shear Bond Strength of Contemporary Universal Composite Resins

The surface gloss, radiopacity and enamel/dentin shear bond strengths (SBS)s of five commercially available contemporary universal composite resins (CR)s were examined. The tested universal CRs were as follows: G-aenial A’CHORD (GA), Charisma Diamond (CD), Neo SpectraTMST(NS), Filtek(F) and Estelite Asteria(EA). Twelve cylindrical specimens per group were fabricated and gloss measurements were performed using a gloss meter after polishing and darkening. Five specimens of each group were radiographed using a CMOS sensor alongside an aluminum stepwedge, human enamel and dentin. The mean gray values were measured with a computer program. A total of 120 bonded human enamel and dentin specimens were subjected to SBS test. To analyze surface gloss, radiopacity and SBS we used Kruskall–Wallis, Wilcoxon signed rank, Welch tests and one-way ANOVA. Games–Howell, Tukey’s HSD tests, and Dunn’s multiple comparisons were used for multiple comparisons (p &lt; 0.05). In terms of gloss units of the materials after polishing and darkening, the highest surface gloss was achieved with GA, followed by NS, F, CD and EA (p &lt; 0.001). All the tested CRs showed significantly higher radiopacity values in comparison with dentin (p &lt; 0.05). CD and NS presented higher radiopacity values, while other CRs were, in decreasing order; F, GA and EA (p &lt; 0.001). The SBS ranking varied for enamel and dentin, and the adhesive failure was detected at a higher rate. Commercially available contemporary universal CRs display different surface gloss, radiopacity and SBS properties.

Effect of topical fluoride applications on residual monomer release from resin-based restorative materials

BackgroundThe effects of topical fluoride applications on the release of monomer ingredients from resin-based dental materials by immersion in various extraction solutions are unclear. The aim of this study was to determine the effect of topical fluorides (APF and NaF) on the elution of residual monomers (Bis-GMA, TEGDMA, UDMA, and HEMA) from resin-based materials.MethodsNinety specimens were prepared, 30 bulk-fill composite resin, 30 nanohybrid universal composite resin, and 30 polyacid-modified composite resin (compomer). These were randomly divided into three groups based on fluoride application procedures. Each specimen was kept in 75% ethanol solution, and residual monomers released from materials were analyzed using high-performance liquid chromatography (HPLC) after 10 min, 1 h, 24 h, and 30 days. The groups were compared using the Mann Whitney U and Kruskal Wallis tests. Measurements were analyzed using the Friedman and Wilcoxon signed-rank tests.ResultsFluoride applications generally had no considerable effect on the amount of residual monomer released from resin-based restorative materials. The amount of monomer release after topical APF application was similar to the release in the control group and was lower than the release in the NaF group. The release of monomers from the resin-based material used in the study did not approach toxic levels at the applied time intervals. The compomer released lower amounts of monomer than other resin-based materials.ConclusionsFluoride applications do not increase monomer release from resin-based restorative materials. However, compomers should be employed by clinicians due to their lower monomer release compared to other resin restorative materials. The release of monomers from all the resin-based materials did not approach toxic levels at the applied time intervals.

Two-year retrospective evaluation of monoshade universal composites in direct veneer and diastema closure restorations.

The aim of this retrospective evaluation was to assess the short-term outcome of two monoshade universal resin composites with high chameleon effect in anterior direct veneer and diastema closure restorations, and to investigate the possible reasons for failure. Patients subjected to veneer and diastema closure restorations with two monoshade universal resin composites (Essentia Universal Shade; EU, GC Corp., and Omnichroma; OC, Tokuyama) operated between January 2018 and March 2019 were selected for the present retrospective evaluation. A total of 159 composite restorations (78 veneers and 81 diastema closure restorations) performed by a single operator in 44 patients (mean age: 33.6) were included in the study. Two blinded and calibrated examiners performed 1- and 2-year assessments of the restorations with respect to FDI criteria, using medical/clinical history and dental photography records. Data were analyzed using Pearson Chi-square with Continuity Correction, Fisher's Exact tests, and Cox regression (a < 0.05). The cumulative overall survival rates of EU and OC restorations were 94.6% (97.3% for the first year) and 88.6% (95.3% for the first year), respectively, with no significant difference from each other (p=0.316). The cumulative overall survival rates of direct veneer and diastema closure restoration types were 90.2% (95.1% for the first year) and 92.4% (97.4% for the first year), respectively, with no significant difference (p=0.559). The reasons for failure were evaluated as fracture of the restoration, failure in esthetic anatomical form, and color mismatch. All the failed direct veneer restorations were due to fractures (FDI score of 5.4), whereas 5 of 6 failed diastema closure restorations were due to color mismatch (FDI score of 3.4). Regarding the composite materials, there were no significant differences between the success rates of the restoration types (p=0.442 for EU, p=1.000 for OC). With respect to the restoration types, there were also no significant differences between the success rates of the resin-based composites (p=1.000 for direct veneer restorations and p=0.228 for the diastema closure restorations). In addition, no significant difference was observed between male and female patients regarding the acceptable and unacceptable scores (p=1.000). The 2-year clinical performance of the two monoshade universal composites in anterior veneer and diastema closure restorations were both considered successful and similar. Despite the lack of shade selection, both monoshade universal composites presented a successful color match. However, the diastema closure restorations might be more prone to color mismatch compared to the veneers over time, while veneer restorations presented more fractures than the diastema closure restorations. Monoshade universal composites presented successful short-term clinical outcomes regarding both function and esthetics in anterior direct veneer and diastema closure restorations.

Assessment of Micro-Hardness, Degree of Conversion, and Flexural Strength for Single-Shade Universal Resin Composites.

Single-shade universal resin composites (SsURC) are preferred in clinical practice to reduce time for shade selection and obtain good esthetic results. In this study, the static mechanical properties of seven new SsURCs were investigated, their spectral analyzes were performed and scanning electron microscopy (SEM) evaluations were presented. Charisma Diamond One/DO, Admira Fusion x-tra/AFX, Omnichroma/OC, OptiShade/OS, Essentia Universal/EU, Zenchroma/ZC, Vittra APS Unique/VU were used in a three-point bending test to determine flexural strength (FS) and elastic modulus (EM); Vickers micro-hardness (VHN) and hardness-ratio (HR) were performed with a micro-hardness tester from top/bottom after 24-h/15-days of storage in distilled water at 37 °C (±1 °C). The degree of conversion (DC) was assessed by using Fourier transform infrared spectroscopy (FTIR). The structure of the resin matrix and filler content were assessed by SEM. Data were analyzed using IBM SPSS V23 and the R program and the significance level was taken as p &lt; 0.05. The main effect of the tested SsURCs was found to be statistically significant on FS, EM, VHN, and DC values (p &lt; 0.001). Bis-GMA free SsURCs (AFX, DO, VU) showed better DC and HR except for OC. All seven tested SsURCs conform to the requirements of ISO standards for dental resin composites for all tested categories.

The Effects of Selected Mouthwashes on the Surface Microhardness of a Single-shade Universal Resin Composite: In Vitro Study

Aim: To investigate the effects of selected alcohol-free mouthwashes with different formulations (zinc-hydroxyapatite, hydrogen peroxide, and sodium fluoride) on the surface microhardness of a single-shade universal resin composite. Materials and Methods: Forty disc-shaped specimens (8 × 2 mm) from the universal resin composite (Omnichroma®), and a nano-hybrid composite (Tetric® N-Ceram) were prepared. After polymerization, baseline surface microhardness values were recorded using Vickers microhardness tester. The samples from each material were randomly assigned to 4 groups ( n = 10) and immersed in 20 ml of the mouthwashes: Biorepair®, Listerine®, Colgate® Optic White, and distilled water (control). The samples were kept in the immersion solutions for 24 hours, and post-immersion microhardness values were recorded. Data were analyzed with one-way ANOVA and paired sample t-tests at p &lt; .05. Results: Significant reduction in microhardness was observed in all resin composite groups after immersion in the mouthwashes compared to baseline values ( p &lt; .0001). The highest microhardness reduction in Omnichroma® group was observed after immersion in Colgate® Optic White; and Tetric® N-Ceram group after immersion in Listerine® mouthwash. For both materials, the least reduction in microhardness was observed after immersion in Biorepair®. Microhardness values for Omnichroma were significantly higher than Tetric® N-Ceram ( p &lt; .0001). However, Omnichroma exhibited a significantly greater reduction in microhardness after immersion in the tested mouthwashes. Conclusion: In vitro simulated use of the investigated mouthwashes negatively affected the surface microhardness of both tested resin composites. The observed effects were both mouthwash and material dependent.

Color Change Evaluation of Three Universal Resin Composites after Storage in Water: An In Vitro Study

Aim: The aim of this in vitro study was to evaluate the color changes of three different universal resin composites after immersion in distilled water for one month. Materials and Methods: Omnichroma, Estelite Σ Quick, and Filtek Universal Restorative were investigated. Ten disk shaped specimens (6 mm diameter, 2 mm thickness) were prepared according to the manufacturers’ instructions for each material. After polishing, initial color measurements were taken followed by individual storage of the specimens in distilled water at 37 °C for one month when color measurements were repeated. The change in the color of each resin composites (Δ E00) was calculated with a digital method, using the CIEDE2000 color difference formula. The data were analyzed using one-way ANOVA followed by Tukey post-hoc test ( P &lt; .05). Results: All resin composites exhibited acceptable color change after one month. Omnichroma exhibited the highest color change (2.26 ± 0.48) value while Filtek Universal Restorative showed the lowest (1.14 ± 0.38) value. All color parameters influenced the Δ E00 values in all groups except Filtek Universal for Δ L* and Δ b values. Conclusion: When performing composite resin restorations, especially for esthetic purposes, polymerization may lead to change in the color of restorative material over time, but it should be considered whether this is within acceptable limits.