Filtek Z250 Research Articles

Effect of aging and fiber-reinforcement on color stability, translucency, and microhardness of single-shade resin composites versus multi-shade resin composite.

The purpose of this study was to evaluate the effect of aging and fiber-reinforcement on the color stability, translucency, and microhardness of single-shade resin composites versus multi-shade resin composite. Four resin composites (Filtek Z250, Omnichroma, Vittra APS Unique, Zenchroma) were tested. Three subgroups of specimens were prepared for each of the composites: control, polyethylene fiber-reinforcement, and glass fiber-reinforcement- groups (n = 10/per group). The samples were subjected to aging for 10,000 thermal cycles. Color differences (ΔE00 ) were calculated after aging. Relative translucency parameter (RTP00 ) and microhardness values were calculated before and after aging. A two-way analysis of variance and the generalized linear model was used (p < 0.05). The lowest and highest ΔE00 values were found for Filtek Z250 (0.6 ± 0.2) and Omnichroma resin composites (1.6 ± 0.4), respectively. The ΔE00 value of the polyethylene fiber-reinforcement group (1.2 ± 0.6) was significantly higher than the ΔE00 value of the glass fiber-reinforcement group (1.0 ± 0.4, p < 0.001). The RTP00 value of the glass fiber-reinforcement group (1.92 ± 0.78) was significantly higher than the RTP00 value of the polyethylene fiber-reinforcement group (1.72 ± 0.77, p < 0.001). The highest microhardness values were found in glass fiber-reinforcement group (76.48 ± 17.07, p < 0.001). Single-shade resin composites were more translucent, had higher color change, and lower hardness than multi-shade resin composite. For relative translucency and microhardness, statistical significance was found in the material and fiber type interaction. The glass fiber-reinforcement provided higher translucency, lower color change and higher microhardness values than polyethylene fiber-reinforcement group after aging. Thermocycling had a significant impact on the color stability, translucency parameter, and microhardness of the tested resin composite materials. Single-shade resin composite materials have greater color-changing potential. The glass fiber-reinforcement optimize resin material mechanical properties and color stability more than polyethylene fiber-reinforcement.

Effect of Lemon Juice, Apple Cider Vinegar and Green Tea on Microhardness of Nanohybrid resin composite: An In-vitro study

This study aimed to evaluate effect of Lemon Juice, Apple Cider Vinegar and Green Tea on microhardness of nanohybrid resin composite using vickers microhardness tester. Materials and methodology: Forty specimens of nanohybrid resin composite (3M ESPE Filtek Z350 XT) were prepared and polished the prepared discs using sandpaper. Before immersion of prepared composite discs in prepared solutions the baseline data of microhardness of each prepared composite discs were recorded by using Vicker’s microhardness tester. The prepared composite discs were divided into 4 groups (n=10) and alternatively immersed in 25 ml of prepared solutions namely Green tea, Apple Cider Vinegar, Lemon Juice and Artificial saliva for 5 sec and then in 25 ml of artificial saliva for another 5 sec and the procedure was repeated for 10 cycles. After following the above mentioned procedure, artificial saliva was used as storage media for 24 hours. For the next 28 days, this entire process was repeated. The microhardness test was carried out prior to immersion and then at intervals of 7, 14, 21 &amp; 28 days after immersion in respective solutions. Results: Two-way analysis of variance (ANOVA) with repeated measurements was carried out for the obtained data. Artificial Saliva demonstrated highest microhardness values at all time points, followed by Green Tea and Lemon Juice. Apple Cider Vinegar showed the least microhardness values of all the four groups tested. Conclusion: All the beverages significantly reduced surface microhardness of nanohybrid resin composite, especially at the end of 28 days. Immersion in apple cider vinegar caused more reduction in surface hardness over time when compared to other beverages. The outcome on microhardness of nanohybrid resin composite by these beverages on depended upon time the latter was exposed and also the chemical composition of beverages. Keywords: Apple Cider Vinegar, Green Tea, Lemon Juice, Microhardness, Nanohybrid resin composite, Vickers Microhardness Tester

Color stability of composite materials to food colorants: A laboratory study

BACKGROUND: Maintaining the esthetic characteristics of direct composite restorations for a long time is relevant. The color stability of food colorants is an important esthetic characteristic of a composite material. Comparative information about the color stability of modern composite restorative materials and recommendations based on optimal clinical results for direct composite restoration are of interest.&#x0D; AIM: To compare the color stability of modern composite restorative materials with the most common food colorants in laboratory conditions.&#x0D; MATERIALS AND METHODS: The color stability of modern restorative materials, namely, Restavrin (Technodent, Russia), GrandioSO (VOCO, Germany), Harmonize (Kerr, USA), Charisma Classic (Kulzer, Germany), Filtek Z250 (3M, USA/Germany), and Estelite Asteria (Tokuyama, Japan), were assessed. Black coffee, black tea, carbonated soft drink cola, dry red wine, and cognac were used as coloring solutions. The samples were exposed for 14 days, and the temperature was 37 C. The control solution was distilled water. Vita Easyshade Advance 4.0 spectrophotometer was used. The average deviation of the color of the studied samples from the reference indicators (∆E), total color stability of the studied materials ( ∆Em), and coloring potential of different coloring solutions in relation to composite materials ( ∆Ec) were determined.&#x0D; RESULTS: The deviation of the color of the studied samples of composite materials from the reference indicators (∆Е) depending on the coloring solution was assessed. The total color stability of the studied materials in relation to food colorants ( ∆Em) as this characteristic deteriorates was as follows: Estelite Asteria, 8.640.08; Harmonize, 10.300.14; Restavrin, 12.300.12; GrandioSO, 12.960.10; Charisma Classic, 13.940.14; and Filtek Z250,15.820.15. The most aggressive food colorants with respect to composite restorative materials were black coffee ( ∆Ec=20.080.12), dry red wine ( ∆Ec=19.180.10), and black tea ( ∆Ec=18.54 0.15).&#x0D; CONCLUSION: Information about the color stability of composite materials in relation to food colorants allows planning the restoration of teeth located in an esthetically significant area, taking into account the eating habits of patients.

A comparative evaluation of mechanical wear of adhesives used for bonded retainers that underwent brushing for 1hour under 36mm of linear action, using computer-aided 3D scan-an in vitro study.

The aim of the present study was to comparatively evaluate the mechanical wear of adhesives used in bonded retainers. Eighty mandibular acrylic teeth were included in the study that were divided into 4 different groups based upon the composite used. Each acrylic tooth was bonded with a retainer wire and composite of their respective group (Heliosit, Restofill, Tetric-N-flow, and Filtek Z350 XT). These bonded acrylic teeth were subjected to 3D scan in order to evaluate the volume and surface area of the composite. The 3D scans were recorded using MEDIT 3D scanner. After evaluating, the samples were subjected to brushing with the aid of a custom-made brushing simulator using a toothbrush with soft bristles and toothpaste slurry. The samples were subjected to 1hr of brushing. These samples were again subjected to 3D scans to evaluate (post-test volume and surface area) and underwent statistical analysis. The results showed the Heliosit group exhibited the highest mean volume (1.76mm3) and surface area (4.81mm2) difference between the pre-test and post-test values whereas the least mean volume difference (1.10mm3) and surface area difference (3.21mm2) were seen in the Tetric-N-flow group. All the four composites underwent change in the mean surface area and volume after being subjected to brushing, suggesting that the composites routinely used for bonding fixed bonded lingual retainers are subjected to changes due to abrasion. The Heliosit group, which showed least filler loading among the 4 composites, exhibited least resistance to wear, whereas the Tetric-N-flow group which had highest filler loading among the composites exhibited highest resistance to wear. The most crucial phase during orthodontic treatment is the retention phase. This phase is responsible for the long-term results of the treatment. The retainers that are placed in the oral cavity are subjected to changes due to oral environment, chemical changes, and mechanical changes. These changes have a direct effect on the retainers, which tend to alter their properties. Thus, the effects of these changes are to be studied thoroughly.

Impact of Shelf-Life Simulation on a Self-Adhesive Composite: Polymerization Kinetics, Chemical and Color Stability.

To determine the polymerization kinetics and color stability of a self-adhesive and conventional resin composite after accelerated shelf-life simulation. Two composites were tested - universal Filtek Z250 (3M Oral Care) and self-adhesive Constic (DMG). They were stored for 2 months in an incubator to simulate an Arrhenius aging model (60°C) and tested at 5 different time points. Polymerization kinetics (n = 3) were studied using an attenuated total reflectance technique (ATR), through continuous FTIR spectral acquisition (20 min). Spectra were obtained before, during and after 20 s of light curing. With the spectral data, qualitative analysis was performed yielding chemical stability, and quantitative data including extrapolated degree of conversion (DCmax) and polymerization rate (Rpmax) were assessed. To evaluate color stability (n = 3), a spectrophotometer was used to record CIELAB color parameters. Inferential statistics, including repeated measures two-way ANOVA were carried out at a significance level of 5%. The composites did not appear to undergo significant chemical changes after 2 months of accelerated aging. There was a significant impact of aging on the mean DCmax (p < 0.001). Similarly, a reduction in Rpmax, measured for both composites, was also noted (ANOVA; Z = 203.7; p < 0.001). The two-way ANOVA confirmed that the composite had no influence on the color stability (F = 0.94; p = 0.34), while aging did (p = 0.013). Minimal changes in absorbance levels were noted for both composites, without overly affecting their chemical composition. The presence of an acidic monomer did not seem to potentiate the degradation of the self-adhesive composite. This composite even showed greater color stability after aging.

The comparison of the repair bond strength of the composite resin to direct and indirect composite restorations with different surface preparations.

Indirect restorations have been employed in restorative dentistry to solve some of the drawbacks of direct restorations. The aim of this study was to evaluate the effect of different modes of a universal adhesive resin on the repair capacity of two indirect resin composites and a direct resin composite. Indirect composite resins (Ceramage and Gradia Plus) and a direct composite resin (Filtek Z250) were prepared in a plastic mold with a height and diameter of 2-mm and 6-mm, respectively. Composite blocks were thermocycled (5000 cycles, 5°C-55°C). Then, according to their surface treatments, composite blocks were categorized into six-groups: Group 1: ER (etch&rinse), Group 2: SE (self-etch), Group 3: Bur+ER (bur+etch&rinse), Group 4: Bur+SE (bur+self-etch), Group 5: Bur+Silane+ER (bur+silane+etch&rinse), Group 6: Bur+Silane+SE (bur+silane+self-etch), respectively. After surface treatments and adhesive application for bonding with a direct resin composite, all groups were then thermocycled before performing shear-bond-strength-test. Failure modes were evaluated using a stereomicroscope. Data were analyzed by two-way-ANOVA and Bonferroni-test (P<0.05). The highest bond-strength values were obtained for Bur+Silane+SE groups, while the lowest values were obtained for the Bur+Silane+ER groups for all materials. Statistically significant differences were observed between the Bur+Silane+ER group and ER, Bur+ER and Bur+Silane+SE groups in Gradia Plus (P<0.05). The self-etch-mode of the universal-adhesive and silane applications led to the increase in the repair-strength of the adhesive in the Filtek Z250 and Ceramage. The self-etch-mode of the universal-adhesive might be used to reduce adhesive-application-steps in the clinical repair procedures.

Examining Vicker Hardness and Wear Volume Minimization in Composite Resin with Different Filler Dimensions via Scanning Topography

Aim: To compare the surface hardness of the nanohybrid resin composite with the other filler-containing resin composites. Material and Method: Abrasive wear properties of four types of resin composites: Harmonize (HM), Tetric N-Ceram (TNC), Filtek Z250 (Z250), and Filtek Z350 (Z350). Each composite had six 10 mm-diameter, 6 mm-thick cylindrical specimens for testing. The wear test involved subjecting the specimens to 800 cycles of abrasive wear under a 17 kg load. Surface hardness and weight loss were measured using a Vickers indenter micro-hardness tester after polishing. Surface morphology investigation was carried out using SEM on three specimens from each composite after the wear test. To identify significant differences in the wear characteristics of the resin composites, statistical analysis was conducted using one-way analysis of variance (ANOVA) and the Tukey HSD test (with α = 0.05). Results: The highest volumetric wear loss was observed in the Z350 XT nano-filled resin composite (71.19±2.49 mm3). The lowest was found in Z250 micro hybrid restorative material (36.33±1.57 mm3). The highest Vickers hardness was found in the Z250 micro-hybrid restorative material (111.24±2.1). Moreover, the lowest microhardness was found in tetric N ceram (TNC) (58.41±1.22). Conclusion: The wear resistance of micro-hybrid resin composite Z250 was found to be superior to that of other composite resins tested in the study.

Effect of Acidic Beverages on the Hardness, Elastic Modulus and Wear Resistance of Giomer and Nongiomer Bulk-fill Materials.

The aim of this study was to evaluate and compare the effect of acidic beverages on the hardness, elastic modulus, and wear resistance of four different resin-based restorative materials. A total of 128 specimens (10 mm diameter, 4 mm thickness) were prepared from a conventional resin composite (Filtek Z250 [Z250]), a giomer bulk-fill (Beautifil Bulk Restorative [BBR]) and two nongiomer bulk-fill materials (Tetric N-Ceram Bulk Fill [TNC] and SonicFill 2 [SF2]). Each material group was divided into four subgroups (n=8) according to the storage media: artificial saliva (control), orange juice, regular Coke, and sports drink. The experimental specimens were immersed in the solutions for 30 minutes, five times a day for 5 days and kept in artificial saliva for an hour between the immersion periods. Control specimens were stored in artificial saliva for 5 days. The nanoindentation test with a Berkovich diamond tip was used to determine the hardness and elastic modulus before and after the 5-day storage periods. Following the nanoindentation tests, the specimens were subjected to a chewing simulator for 120,000 cycles. The specimens were then scanned with a three-dimensional scanner. The wear resistance was analyzed by measuring the volume and height loss. Specimens were observed by environmental scanning electron microscopy. The statistical analyses were performed by analysis of variance, Tukey HDS test, and paired samples t-test (α=0.05). Z250 showed significantly higher elastic modulus in all groups (p<0.05). After erosive cycles, the greatest decrease in hardness and elastic modulus was observed for BBR. TNC showed higher wear resistance than the other resin-based materials (p<0.05). The BBR specimens immersed in acidic solutions showed higher wear rates than the artificial saliva group (p<0.05). Conventional resin composite showed higher hardness and elastic modulus than bulk-fill materials when exposed to acidic beverages but comparable or lower wear resistance. Degradation due to acidic beverages most affected the mechanical properties of giomer bulk-fill.

An in vitro Study on the Antibacterial Efficiency of the Various Composites in the Children: An Original Research.

Many generations of esthetic materials have been introduced in the market, the most popular being the composites. Bioactive restorative materials are a recent development in restorative dentistry. However, the main cause of secondary caries is the development of bacterial plaque on these restorations. Current in vitro study was conducted to assess the antibacterial properties of three common composites. Only a single parameter was assessed in this study, which was the bacterial colonies on each of the material blocks that were confined in the same experimental conditions. For this assessment, three composite materials were used that were made into blocks of 10 each. "Beautifil Flow Plus X" and "ACTIVA BioACTIVE" were used as the interventional groups, while "Filtek Z250 XT" was used as the control. Streptococcus mutans was used as an antibacterial test subject, and confocal laser scanning microscopy was used to observe the results. When compared to other groups, ACTIVA BioACTIVE exhibited the highest quantity of dead bacteria on the material surface. There was significant variance among the three composites in the number of live and dead bacterial colonies. The highest antibacterial efficacy among the evaluated materials allows for a conclusion.

Thickness-Dependent Light Transmittance and Temperature Rise in Dual-Cure Bioactive and Light-Cure Bulk-Fill Composite Resins.

This study aimed to assess the light transmittance (T) and temperature increase through different increments of dual-cure bioactive bulk-fill restorative material (ACTIVA), light-cure bulk-fill, and conventional composite resin materials. Cylindrical specimens with a diameter of 8 mm and heights of 1, 2, 3, and 4 mm of ACTIVA, Tetric-N-Ceram bulk-fill (TBF), Filtek One bulk-fill (FBF), and Filtek Z250 (FZ) (n = 6 per group, 96 in total) were light-cured with a visible blue low-intensity light-emitting diode (LED) (650-800 mW/cm2 irradiance). T, and the temperature increase, were measured using an optical power meter and a digital thermometer during curing. The T mean values ranged between 0.012 and 0.239 (76.02 to 98.81% light attenuation), while the temperature rise mean values ranged between 9.02 and 20.80 °C. The parameters, including material type (partial eta squared (ηp2) = 0.284, p < 0.0001), thickness (ηp2 = 0.284, p < 0.0001), and their interaction (ηp2 = 0.185, p = 0.047), significantly affected the T values, whereas only the material type (ηp2 = 0.352, p = 0.047) affected the temperature rise values. The T and temperature rise mean values were highest in ACTIVA increments of 1-mm increments, in particular, showing the highest T mean values, followed by similar increments of TBF. A significantly higher T was found in 1-mm increments compared to thicker increments for all materials (p < 0.0001), and a significant positive correlation existed between T and temperature rise values (r = 0.348, p = 0.001). These findings show that the bioactive material ACTIVA and TBF allow for better T than the other materials, with ACTIVA recording a higher temperature rise. However, the large light attenuation observed for all materials, irrespective of thickness, suggests that curing in more than one location with a low-intensity LED is necessary to optimize the curing process. Furthermore, incremental filling of bulk-fill materials using a low intensity LED could be beneficial.

Investigating the impact of flowable composite liner on the fracture strength and microleakage of large composite resin restorations of primary anterior teeth.

To investigate the effect of pre-cured and co-cured flowable composite liner on fracture strength and microleakage of primary anterior teeth with extended composite resin restorations. In the current in vitro experimental study, the crowns of 54 extracted primary canine teeth were cut 1mm above the CEJ, and a pulpectomy procedure was performed. The samples were randomly divided into three groups to restore the coronal part up to 4mm above the CEJ. In group 1, the samples were built up with Filtek Z250 packable composite resin. In group 2 (pre-cure), first, 1mm of Filtek Z350 XT flowable liner was applied to the sample, and after curing, the restoration process continued using packable composite resin. In group 3 (co-cure), the flowable composite liner was cured while the first layer of packable composite resin was applied; then, the same restorative procedure similar to the other groups was followed. The samples' cross-sectional area in the fracture strength test was calculated by AutoCAD software. Subsequently, the samples were subjected to a force in a universal testing machine. The samples related to the microleakage experiment were cut vertically, and then, the dye penetration percentage (10% methylene blue) was measured under a stereomicroscope. ANOVA was used to analyze the data. Mean fracture strength in group 2 was significantly higher than in group 1 (P = 0.016). The microleakage mean in group 3 was significantly lower than in groups 1 (P = 0.000) and 2 (P = 0.026). The flowable composite liner and its relevant separate curing increased the fracture strength of composite resin restorations. However, less microleakage was reported in the group where the liner was applied as a co-cure.

In vitro comparison of the physical and mechanical properties of an ormocer with an ormocer-based composite and a nanocomposite restorative material.

To compare an ormocer with a first generation ormocer-based composite and a nanocomposite in terms of surface roughness, surface hardness, and microleakage. An ormocer (Admira Fusion), a first generation ormocer-based composite (Admira) and a nanocomposite (Filtek Z350 XT) were prepared strictly in accordance with the manufacturer's instruction and recommendation to provide optimal material properties. Twelve disk samples of each material were evaluated to assess both surface roughness and surface hardness. For surface roughness, all samples were finished, polished, and Ra values measured with a profilometer. For surface hardness, samples were stored in an incubator, polished and a Vickers diamond indenter was used to record values. For microleakage, 36 standardized, Class V cavities were prepared and randomly divided into three groups. Restored teeth were thermally fatigued, immersed in 2% methylene blue solution for 48 h, sectioned, and scored for occlusal and gingival microleakage. Statistical significance was set at p < .05. The one-way analysis of varianceidentified no significant difference in terms of surface roughness between the three material groups (p > .05). A significantly higher surface hardness was identified for the nanocomposite compared to both the ormocer (p < .001) and ormocer-based composite (p < .001). Fisher's exact test identified no significant difference in terms of occlusal microleakage (p = .534) and gingival microleakage (p = .093) between the three material groups. No significant differences in terms of surface roughness or microleakage were noted. The nanocomposite was significantly harder thanthe ormocer materials.

Hardness and Depth of Cure of Conventional and Bulk-Fill Composite Resins in Class II Restorations with Transparent and Metal Matrix Strips.

Objectives: Hardness is relevant to the degree of conversion (DC) and depth of cure (DoC). The aim of this study was to determine the micro-hardness and DoC of conventional and bulk-fill composite resins in class II restorations using metal and clear matrix bands. Materials and Methods: Twelve specimens of each of the two composite resins, i.e., Filtek Z350 XT bulk-fill and Gradia posterior conventional composite, were prepared in the form of a class II cavity in a tooth mold, using a clear or metal matrix band. All specimens were cured and stored at 37°C for 24 hours. Vickers hardness was measured as a function of DoC at 2mm intervals. Data were analyzed by two-way ANOVA (alpha=0.05). Results: The bulk-fill composite exhibited significantly higher hardness levels than the conventional composite in all tested surfaces (P<0.001). However, while the metal matrix band had a significant impact on the bottom surface (P=0.059) and also on the furthest surface from the matrix and light source (P=0.04), it did not have a consistent effect across all tested surfaces. The simultaneous interaction of the composites and matrix band types in all surfaces, did not show significant differences in hardness values. The highest bottom-to-top surface hardness ratio (73%) was observed in the conventional composite near the metal matrix band. Conclusion: In deep class II cavities, the bottom-to-top surface hardness ratio did not reach the maximum of 80%, neither for bulk-fill nor conventional posterior composites. Therefore, in such cavities extended light-curing and more incremental composite placement is needed.

Fracture load and failure mode of semi-direct resin composite occlusal veneers: Influence of design and mechanical cycling

AimsTo evaluate the influence of the type of preparation and mechanical cycling on the fracture load and failure mode of semi-direct posterior resin composite restorations. MethodsIn total, 70 healthy third molars were used; 10 belonging to the control group (C - unprepared teeth) and 60 teeth prepared and restored with nanoparticle resin composite, divided into 3 groups (n = 20): O - exclusively occlusal preparation (Table Top); OV - occlusal preparation with buccal extension (Veneerlay); OVP - Occlusal preparation with chamfer on the proximal and buccal-lingual/palatal surfaces (Overlay). The preparations were performed with diamond burs with a thickness of 1 mm. The restorations were made with nanoparticulate resin composite (Filtek Z350 XT) and subsequently received additional polymerization (thermoprocessing). Cementation was performed with the use of universal adhesive system (Single Bond Universal) on dental substrate and dual resin cement (RelyX ARC). Half of the teeth in each group (n = 10) were submitted to mechanical cycling, simulating 6 months of clinical service (5 × 105 fatigue cycles), under dynamic loading of 130 N, at a frequency of 2Hz. Fracture load tests were performed in a universal testing machine with a 200 kgf load cell. Failure mode was classified using scores. Generalized linear models and Fisher Exact tests were applied to the data (significance level of 5%). ResultsThere were no significant differences between the types of preparation (p = 0.9435), or relative to cycling (p = 0.3764). The Fisher Exact Test showed a significant association between the groups and the type of failure (p = 0.0006), with preparations O (with cycling) and OVP (with and without cycling) exhibiting most failures with restoration fractures without involvement of the dental remnant. ConclusionsSemi-direct restorations showed resistance to fracture load similar to that of healthy teeth and were capable of withstanding functional masticatory loads. The type of preparation influenced the failure mode of teeth. The Table Top and Overlay types of preparations were those had fewer catastrophic failures, suggesting that since they are more conservative preparations, they made it possible for the tooth to receive a new restorative procedure in the future in cases of failures.

Comparative Efficacy of Four Stain Removal Methods for Bleach-Shade Composite Resins after Immersion in Staining Solutions: An In Vitro Study.

Bleach-shade composite resins were recently introduced to the market due to the high demand of patients for whiter teeth. This study sought to compare four stain removal methods for bleach-shade composite resins. Seventy-two discs were fabricated from each of the Filtek Z350 XT and Gradia XBW composite resins and immersed in coffee or sour cherry juice staining solutions. Each group was then divided into four subgroups to assess the efficacy of four stain removal methods (finishing with soft-lex disk "brush with pumice" bleaching with carbamide peroxide 16%, bleaching with hydrogen peroxide 40%). The color of each specimen was measured by Easyshade spectrophotometer, and data were analyzed using SPSS 25 statistical package for social sciences. The home-bleaching technique was more effective than the office-bleaching and pumice for the removal of sour cherry juice stain (ΔE = 1.93) and coffee stain (ΔE = 3.32) from Gradia composite discs, almost returning the baseline original color. The Sof-Lex discs were more effective than the pumice for the removal of sour cherry juice stain (ΔE = 4.11) and coffee stain (ΔE = 4.93) from Z350 composite discs but not return the baseline original color. Filtek Z350 had more discoloration than Gradia Direct. The different materials and solutions reacted differently to the four stain removal methods. In GCJ group after all stain removal methods, ΔE reduced to a clinically acceptable level.

Deterioration of direct restorative materials under erosive conditions with impact of abrasion and attrition in vitro

Objective To compare the cumulative impact of sequential wear on mechanical properties and appearance of a composite resin (CR), Filtek Z250®, a glass ionomer GI, Fuji IX GP®, and a glass hybrid (GH), Equia Forte®. Material and Methods Six equally sized specimens of each material were subjected to wear tests, i.e., simulation of brushing, chewing and acidic liquid exposure, mimicking at least 6 months of clinical exposure. Surface roughness, hardness, substance loss and degree of shade lightness were determined. Results Following wear tests, significant increase in surface roughness and decrease in hardness values were observed for all materials (p < .05). Significantly larger substance loss was found in Equia Forte® specimens compared to Filtek Z250® (p < .05), while that of Fuji IX® exceeded the measurement capacity of the instrument. Opposite to the two other materials, the shade of Filtek Z250® became darker. Conclusions Sequential wear exposure mimicking abrasion, erosion and attrition to products representing CR, GI and GH, caused weakening and change in appearance of the materials. The composite resin was the most mechanically resistant to the sequential wear.

Effect of immersion and thermocycling in different beverages on the surface roughness of single- and multi-shade resin composites

BackgroundResin composite restorations are highly esthetic restorations, which should have and maintain high surface polish. However, esthetic restorations are subjected to different beverages at variable temperatures, which may affect their surface roughness. This study aimed to evaluate the surface roughness of single-shade (Omnichroma) and multi-shade (Filtek Z350XT) composite materials, following aging by immersion and thermocycling in different beverages, simulating one year of clinical service.MethodsThirty specimens of each material were prepared and divided into 6 subgroups (n = 5). In each material, the grouping of the specimens was as follows: the first subgroup was the as-prepared specimens stored dry without immersion or thermocycling. The second, third, and fourth subgroups were immersed in saliva, tea, and red wine, respectively, for 12 days at 37 °C. The fifth and sixth subgroups were thermocycled for 10,000 cycles, in tea (the fifth between 37 and 57 °C) and in red wine (the sixth between 37 °C and12°C). The resultant surface roughness was measured by two different methods, stylus profilometer and atomic force microscopy (AFM). Intergroup comparison was performed using independent t test, while intragroup comparison was performed using one-way analysis of variance (ANOVA) followed by Tukey’s post-hoc test.ResultsIntergroup comparison between both composites showed no statistically significant differences in all groups using the stylus profilometer roughness measurements (P>0.05), while the AFM measurements showed significant difference (P ≤ 0.05) within all storage media except the as-prepared control (P = 0.0645), where nanofilled Filtek Z350 XT showed lower nano-roughness. Intragroup comparison data were variable, depending on the material, aging conditions, and roughness assessment tool. However, the resultant average surface roughness (Ra) values in all groups did not exceed the threshold value of Ra 0.2 μm.ConclusionsBoth resin composites attained and retained a clinically acceptable surface finish after immersion and thermocycling in different beverages.

Effect of in-office bleaching agent on the surface roughness and microhardness of nanofilled and nanohybrid composite resins.

Background: To compare the surface roughness and microhardness of Ceram.x® SphereTEC™ one and Filtek Z350 XT after in-office bleaching with Pola office. Methods: Twenty samples each of (10 mm diameter and 2 mm height) Ceram.x® SphereTEC™ one and Filtek Z350 XT were prepared. The samples were subjected to three bleaching sessions with 35% hydrogen peroxide (Pola office) with a seven-day interval between each session. Surface roughness and microhardness of the prepared samples prior to and after the bleaching regimen were measured using a profilometer and Vickers hardness tester, respectively. Results: A significant reduction (p <0.001) in the surface hardness of Filtek Z350 XT from 27.67 ± 2.10 to 17.83 ± 1.36 Vickers hardness number (VHN) was observed after the bleaching whereas no significant reduction in surface hardness was observed with Ceram.x® SphereTEC™ one. The adjusted mean (estimated marginal mean) microhardness after bleaching for Ceram.x ® SphereTEC™ one (35.79 ± 1.45) was significantly higher than Filtek Z350 XT (19.54 ± 1.45) (p < 0.001). However, in-office bleaching of these materials did not significantly alter their surface roughness. Conclusions: In office-bleaching with 35% hydrogen peroxide can reduce the microhardness of nanofilled composite. However, the surface roughness was not influenced by the bleaching procedure in both nanohybrid and nanofilled composite resin materials.

Comparative evaluation of marginal microleakage of various restorative materials used in pediatric dentistry – An in-vitro stereomicroscopic study

The longevity of restorative materials depends on the resistance to masticatory forces. The present study was undertaken to evaluate the microleakage properties of different restorative materials. A total of 30 specimen blocks were prepared with 10 samples of each type of restorative material, namely GIC Fuji IX, Filtek Z-350 Composite, and Cention-N. Class I cavities were prepared with dimensions 1.5 x 2 x 2 mm (l x b x h) of cavity size of orthodontically extracted premolars followed by restoration of each test material. We found thatCention-N has shown the least microleakage as compared to other groups. Mean microleakage was the least for Cention-N. It’s a newer restorative material having higher mechanical properties with lesser microleakage. Cention-N is a newer restorative material having promising properties. This material can be used as an alternative restorative material.

The Effect of Chemical Degradation and Polishing on the Gloss of Composite Dental Materials.

This aim of this study was to investigate surface gloss changes of different composite dental materials after chemical degradation or polishing. Five different composites were used (Evetric, GrandioSO, Admira Fusion, Filtek Z550, Dynamic Plus). The gloss of the tested material was measured with a glossmeter before and after chemical degradation in different acidic beverages. Statistical analysis was performed using a t-test for dependent samples, ANOVA, and a post hoc test. For comparison between groups, a level of significance was set at 0.05. Initial gloss values ranged from 51 to 93 at baseline to 32 to 81 after chemical degradation. The highest values were obtained for Dynamic Plus (93.5 GU) and GrandioSO (77.8 GU), followed by Admira Fusion (82 GU) and Filtek Z550 (70.5 GU). Evetric showed the lowest initial gloss values. After acidic exposures, the gloss measurements revealed different patterns of surface degradation. The results showed that the gloss of the samples decreased with time regardless of the treatment. The interaction between chemical-erosive beverages and the composite could lead to a decrease in the surface gloss of the composite restoration. The nanohybrid composite showed less gloss changes under acidic conditions, suggesting that it is more suitable for anterior restorations.