Filtek Bulk Fill Research Articles

Marginal fit of class II cavities restored with bulk-fill composites

Purpose To evaluate the marginal integrity of three types of bulk-fill composite resins in class II cavities. Materials and methods Simple class II cavities with parallel walls were prepared in 40 extracted human sound molars were selected. The overall dimensions and depth of the cavities were standardized as follow: 4 mm length occlusocervically, 4 mm width buccolingually and 2 mm depth axially. The teeth were randomly divided into four groups (n = 10 each): group 1: Tetric N-Bond Universal and Tetric EvoCeram Bulk Fill composite; group 2: Single Bond Universal and Filtek Bulk Fill posterior composite; group 3: Futurabond U and Admira Fusion X-Tra; group 4: Tetric N-Bond Universal and Tetric EvoCeram composite. All samples were thermocycled for 600 cycles. Impressions of the teeth were made using a polyvinyl siloxane then poured with epoxy resin. These replicas gold sputtered and examined under scanning electron microscopy. Results Group 3 recorded the lowest mean marginal gap length value, while group 4 recorded the highest mean marginal gap length value. One-way analysis of variance was used to compare the tested groups at a level of significance (P ≤ 0.001). For width of proximal gap the lowest mean marginal gap length value found in group 3, while the highest mean value of gap width proximally found in group 1. In width of cervical gap the lowest mean marginal gap length value was found in group 3, while the highest mean value of gap width cervically found in group 4. One-way analysis of variance test was used to compare the tested groups at a level of significance (P ≤ 0.05). Conclusion Admira Fusion X-Tra has good results compared to other used bulk fill and conventional composites.

Preliminary data on clinical performance of bulk-fill restorations in primary molars.

In pediatric clinic practice, bulk fill composite is gaining importance for shortened clinical time with a limited shrinkage. The present study evaluated the 1 year clinical performance of bulk fill composite and conventional composite material in occlusal caries of primary molars. The study was designed as randomized single blind clinical trial and a total of 160 restorations were placed in the cavities of the 80 patients. Each patient received two restorations: one with Filtek Z250 (3M ESPE, St Paul, MN 55144, USA); the other restored with Filtek Bulk-Fill Restorative (FBF) (3M ESPE, St Paul, MN, USA). All restorations were clinically evaluated after baseline, 6 months, and 1 year in terms of retention, color matching, marginal discoloration, marginal adaptation, secondary caries, surface texture, anatomic form, and postoperative sensitivity. Besides the descriptive statistical methods, the Friedman test and the Wilcoxon Signed Ranks were used. Bulk fill was found to be worse compared to control with regard to postoperative sensitivity at baseline without statistical significance (P > 0.05). All of the evaluated restorations were retained and were still in function after 1 year (P > 0.05). With respect to marginal discoloration and marginal integrity, there were no significant differences between bulk fill and composite restorations at all intervals (P > 0.05). Based on this short term data, restoration of Class I cavities with both bulk fill and conventional composite restorations can be performed successfully. Postoperative sensitivity can be an issue with the restorations completed with Bulk fill restorative.

Surface changes of various bulk-fill resin-based composites after exposure to different food-simulating liquid and beverages.

To evaluate surface roughness, hardness, and morphology changes of various bulk-fill resin composites eroded by different food-simulating liquids and beverages. One hundred and thirteen specimens were fabricated in polytetrafluoroethylene cylindrical mold (10 mm in diameter and 4 mm in thickness). Before immersion, baseline data of roughness, Vicker's microhardness were recorded and surface characteristics were examined using scanning electron microscopy (SEM). Each product of specimens (SDR, Dentsply; SonicFill, Kerr; Tetric N-Ceram Bulk Fill, Ivoclar Vivadent AG; and Filtek Bulk Fill, 3M ESPE) were divided into 5 groups for spicy and sour soup, spicy soup (Tom Yum), pineapple juice, passionfruit juice, and deionized water (served as a control). Specimens were then alternately immersed in storage agents for 5 seconds and artificial saliva for 5 seconds over 10 cycles. Specimens were stored in artificial saliva for 22 hours. This process was repeated for 28 days. After immersion, surface hardness and roughness of specimens were evaluated at 7, 14, 21, and 28 days and data were analyzed by two-way repeated ANOVA and Tukey's HSD (α = 0.05). Surface morphology of specimens was also examined on day 28. The SDR group had the most statistically significant decrement in hardness (25.65±1.74 kg/mm2 in mean difference) and increment in roughness (0.26±0.10 μm in mean difference; P < .05). Passionfruit juice caused the most surface changes in bulk-fill resin composites. SEM photomicrographs showed surface changes of all resin composites in varying degrees. Acidic food-simulating liquids and beverages significantly increased the surface roughness and decreased surface microhardness of bulk-fill resin composites after evaluation at the end of the 28-day immersion period. For restoration of the affected teeth in patients who consume acidic food and beverages, roughness and erosion of resin composites should be considered. All of bulk-fill resin-based composites except SDR may be suitable for restorations in these patients.

Influence of increment thickness on radiant energy and microhardness of bulk-fill resin composites.

Determining the energy transferred at the bottom of eleven bulk-fill resin composites, comparing top and bottom microhardness's and evaluating the correlation between microhardness and radiant energy were aimed. Samples were placed over the bottom sensor of a visible light transmission spectrophotometer and polymerized for 20 s. The bottom and top Knoop microhardness were measured. Paired t-test and correlation analysis were used for statistics (p≤0.05). In all groups, the bottom radiant energy decreased significantly with increasing thickness. For groups of Aura 2 mm, X-tra Fil 2 and 4 mm, SDR 2 and 4 mm, X-tra Base 2 mm no significant difference was found between top and bottom microhardness. For the bottom levels of Aura, X-tra Fil, Filtek Bulk-Fill Posterior, SDR, X-tra Base groups no significant difference was found between the microhardness's of 2 and 4 mm thicknesses. For X-tra Fil, Tetric Evo Ceram Bulk-Fill, Filtek Bulk-Fill Flowable and Z100 groups radiant energy affected positively the microhardness.

Marginal Gap Formation in Approximal "Bulk Fill" Resin Composite Restorations After Artificial Ageing.

The aim of this in vitro study was to investigate the marginal gap formation of a packable "regular" resin composite (Filtek Supreme XTE [3M ESPE]) and two flowable "bulk fill" resin composites (Filtek Bulk Fill [3M ESPE] and SDR [DENTSPLY DeTrey]) along the approximal margins of Class II restorations. In each of 39 extracted human molars (n=13 per resin composite), mesial and distal Class II cavities were prepared, placing the gingival margins below the cemento-enamel junction. The cavities were restored with the adhesive system OptiBond FL (Kerr) and one of the three resin composites. After restoration, each molar was cut in half in the oro-vestibular direction between the two restorations, resulting in two specimens per molar. Polyvinylsiloxane impressions were taken and "baseline" replicas were produced. The specimens were then divided into two groups: At the beginning of each month over the course of six months' tap water storage (37°C), one specimen per molar was subjected to mechanical toothbrushing, whereas the other was subjected to thermocycling. After artificial ageing, "final" replicas were produced. Baseline and final replicas were examined under the scanning electron microscope (SEM), and the SEM micrographs were used to determine the percentage of marginal gap formation in enamel or dentin. Paramarginal gaps were registered. The percentages of marginal gap formation were statistically analyzed with a nonparametric analysis of variance followed by Wilcoxon-Mann-Whitney tests and Wilcoxon signed rank tests, and all p-values were corrected with the Bonferroni-Holm adjustment for multiple testing (significance level: α=0.05). Paramarginal gaps were analyzed descriptively. In enamel, significantly lower marginal gap formation was found for Filtek Supreme XTE compared to Filtek Bulk Fill ( p=0.0052) and SDR ( p=0.0289), with no significant difference between Filtek Bulk Fill and SDR ( p=0.4072). In dentin, significantly lower marginal gap formation was found for SDR compared to Filtek Supreme XTE ( p<0.0001) and Filtek Bulk Fill ( p=0.0015), with no significant difference between Filtek Supreme XTE and Filtek Bulk Fill ( p=0.4919). Marginal gap formation in dentin was significantly lower than in enamel ( p<0.0001). The percentage of restorations with paramarginal gaps varied between 0% and 85%, and for all three resin composites the percentages were markedly higher after artificial ageing. The results from this study suggest that in terms of marginal gap formation in enamel, packable resin composites may be superior to flowable "bulk fill" resin composites, while in dentin some flowable "bulk fill" resin composites may be superior to packable ones.

Bond strengths of bulk-fill resin composite repairs: effect of different surface treatment protocols in vitro

To evaluate the effect of different surface treatment protocols on the microtensile bond strength (μTBS) of bulk-fill resin composite repairs. Thirty-five bulk-fill resin composite samples (Filtek Bulk Fill) were prepared (5 × 5 × 5 mm) and aged by thermocycling (X5000). Samples were randomly divided into five groups (n = 7): a control (no treatment) and four surface treatment groups (Single Bond Universal [SBU]; phosphoric acid (37%) + SBU; Er,Cr:YSGG laser + SBU; aluminum oxide sandblasting + SBU). Filtek Ultimate Universal composite was used as a repair material. After storage for 24 h in distilled water (37 °C), sticks were obtained and subjected to a μTBS test. The data (MPa) were analyzed by one-way ANOVA with a post hoc test (α = 0.05). Failure mode was evaluated using a light microscope (10×). There were significant differences between the groups (p < 0.05). The lowest bond strength values were obtained in the control group (p < 0.05). No significant difference was observed between Group II (universal adhesive) and Group III (acid etch + universal adhesive) (p > 0.05). The bond strength of Group II was significantly lower than that of the other surface treatment groups (p < 0.05). While Group III showed significantly lower values than those of the laser treatment group (Group IV), similar values were obtained with Al2O3 sandblasting group (Group V). The highest repair bond strength was obtained in Group IV (p < 0.05) which was not significantly different from the Al2O3 sandblasting group (p > 0.05). The predominant failure mode was adhesive. Treatment of aged bulk-fill resin composite surfaces with laser and Al2O3 sandblasting provided higher repair bond strength values.

The Effects of Cavity Preparation and Composite Resin on Bond Strength and Stress Distribution Using the Microtensile Bond Test.

To evaluate the effect of flowable bulk-fill or conventional composite resin on bond strength and stress distribution in flat or mesio-occlusal-distal (MOD) cavity preparations using the microtensile bond strength (μTBS) test. Forty human molars were divided into two groups and received either standardized MOD or flat cavity preparations. Restorations were made using the conventional composite resin Z350 (Filtek Z350XT, 3M-ESPE, St Paul, MN, USA) or flowable bulk-fill (FBF) composite resin (Filtek Bulk Fill Flowable, 3M-ESPE). Postgel shrinkage was measured using the strain gauge technique (n=10). The Z350 buildup was made in two increments of 2.0 mm, and the FBF was made in a single increment of 4.0 mm. Six rectangular sticks were obtained for each tooth, and each section was used for μTBS testing at 1.0 mm/min. Polymerization shrinkage was modeled using postgel shrinkage data. The μTBS data were analyzed statistically using a two-way analysis of variance (ANOVA), and the postgel shrinkage data were analyzed using a one-way ANOVA with Tukey post hoc test. The failure modes were analyzed using a chi-square test (α=0.05). Our results show that both the type of cavity preparation and the composite resin used affect the bond strength and stress distribution. The Z350 composite resin had a higher postgel shrinkage than the FBF composite resin. The μTBS of the MOD preparation was influenced by the type of composite resin used. Irrespective of composite resin, flat cavity preparations resulted in higher μTBS than MOD preparations ( p<0.001). Specifically, in flat-prepared cavities, FBF composite resin had a similar μTBS relative to Z350 composite resin. However, in MOD-prepared cavities, those with FBF composite resin had higher μTBS values than those with Z350 composite resin. Adhesive failure was prevalent for all tested groups. The MOD preparation resulted in higher shrinkage stress than the flat preparation, irrespective of composite resin. For MOD-prepared cavities, FBF composite resin resulted in lower stress than Z350 composite resin. However, no differences were found for flat-prepared cavities. FBF composite resin had lower shrinkage stress than Z350 conventional composite resin. The μTBS of the MOD preparation was influenced by the composite resin type. Flat cavity preparations had no influence on stress and μTBS. However, for MOD preparation, composite resin with higher shrinkage stress resulted in lower μTBS values.

Polymerization Behavior and Mechanical Properties of High-Viscosity Bulk Fill and Low Shrinkage Resin Composites.

The present study determined the mechanical properties and volumetric polymerization shrinkage of different categories of resin composite. Three high viscosity bulk fill resin composites were tested: Tetric EvoCeram Bulk Fill (TB, Ivoclar Vivadent), Filtek Bulk Fill posterior restorative (FB, 3M ESPE), and Sonic Fill (SF, Kerr Corp). Two low-shrinkage resin composites, Kalore (KL, GC Corp) and Filtek LS Posterior (LS, 3M ESPE), were used. Three conventional resin composites, Herculite Ultra (HU, Kerr Corp), Estelite ∑ Quick (EQ, Tokuyama Dental), and Filtek Supreme Ultra (SU, 3M ESPE), were used as comparison materials. Following ISO Specification 4049, six specimens for each resin composite were used to determine flexural strength, elastic modulus, and resilience. Volumetric polymerization shrinkage was determined using a water-filled dilatometer. Data were evaluated using analysis of variance followed by Tukey's honestly significant difference test (α=0.05). The flexural strength of the resin composites ranged from 115.4 to 148.1 MPa, the elastic modulus ranged from 5.6 to 13.4 GPa, and the resilience ranged from 0.70 to 1.0 MJ/m3. There were significant differences in flexural properties between the materials but no clear outliers. Volumetric changes as a function of time over a duration of 180 seconds depended on the type of resin composite. However, for all the resin composites, apart from LS, volumetric shrinkage began soon after the start of light irradiation, and a rapid decrease in volume during light irradiation followed by a slower decrease was observed. The low shrinkage resin composites KL and LS showed significantly lower volumetric shrinkage than the other tested materials at the measuring point of 180 seconds. In contrast, the three bulk fill resin composites showed higher volumetric change than the other resin composites. The findings from this study provide clinicians with valuable information regarding the mechanical properties and polymerization kinetics of these categories of current resin composite.

EFFECT OF THERMAL CYCLING ON MARGINAL SEAL OF DIFFERENT DENTIN SUBSTITUTES

Objectives: To investigate the marginal seal of new dentin substitutes using environmental SEM and evaluate the longevity of the seal after being subjected to thermal stresses. Methods: Four different dentin substitute materials (SDR, DENTSPLY; Sonic Fill, Kerr; Filtek Bulk Fill, 3M ESPE; and Fuji II LC, GC Corporation) were tested in this study. MOD cavities (4mm depth and half of the intercuspal distance width) were prepared on eighty human sound extracted premolars. Teeth were divided randomly into four groups according to the tested material. Each group was further divided into two subgroups (n=10): subgroup A; No thermal cycling was applied, and subgroup B; was subjected to thermal cycling (5±2 oC - 55±2 oC for 1000 cycles). The teeth were sectioned vertically through the resin composite parallel to their long axis in mesiodistal direction. Specimens were then tested for gap formations along pulpal dentin interface using Environmental SEM. Data were tabulated and statistically analyzed. Results: Regardless of thermal cycling; Fuji II showed the statistically significantly highest mean gap distance (26.6 ± 12.6). Sonic Fill showed statistically significantly lower mean value (23.4 ± 4.3). There was no statistically significant difference between Bulk Fill (17.5 ± 1.7) and SDR (16.3 ± 1.5); both showed the statistically significantly lowest mean gap distance. Without thermal cycling, Sonic Fill showed the statistically significantly highest mean gap distance (19.4 ± 1.2). No statistically significant difference was found between Filtek Bulk Fill (16.1 ± 1.0), SDR (15.3 ± 0.9) and Fuji II (14.6 ± 0.7); all showed the statistically significantly lowest mean gap distances. While with thermal cycling, Fuji II (38.5 ± 0.9) showed the statistically significantly highest mean gap distance. Sonic Fill showed statistically significantly lower mean value (27.3 ± 0.9). There was no statistically significant difference between Filtek Bulk Fill (18.9 ± 0.7) and SDR (17.4 ± 1.2); both showed the statistically significantly lowest mean gap distance. Conclusions: Under the test conditions, Bulk Fill and SDR provided an adequate marginal seal, regarding gap distance, when compared to Sonic Fill and Fuji II. Meanwhile, thermal cycling significantly increases gap distance in all tested dentin substitutes, thus affecting longevity.

Thermographic analysis of the effect of composite type, layering method, and curing light on the temperature rise of photo-cured composites in tooth cavities

ObjectivesThe purpose of this study was to investigate temperature rise in the composite and dentin of a class I cavity in extracted human molars under different restoration conditions, including the use of different composite types, layering methods, and curing lights. MethodsOpen occlusal cavities were prepared on 28 extracted human molars. A conventional (Filtek Z250) and a bulk-fill (Filtek Bulk Fill Posterior; BFP) composite were used to restore the preparations. BFP was incrementally layered or bulk-filled. Bulk-filled BFP was cured with two different lights, the Elipar S10 and the BeLite. Each layer was illuminated for 20s, while thermograms of the specimens were recorded for 100s using an infrared thermal camera. Temperature changes on the composite and dentin surfaces were obtained at points of interest (POI) pertaining to successive incremental distances of 0.75mm from the top of the cavity to the pulp. The polymerization kinetics of each composite was determined using photo-differential scanning calorimetry. ResultsThe greatest temperature rise was observed 0.75mm apical from the top of the cavity. All groups showed over 6°C maximum temperature rise (ΔTmax) at the pulpal side of the dentin. Upon curing, Z250 reached ΔT=5°C faster than BFP; however, ΔTmax of the two composites were comparable at any POI. Bulk filling showed greater ΔTmax than incremental filling at 0.75mm apical from the top and in the middle of the cavity. The Elipar S10 light generated faster temperature changes in the curing composite at all recorded positions throughout the depth of the cavity and greater ΔTmax in all POIs compared to BeLite. SignificanceReal-time thermographic analysis demonstrated that the composite type and layering method did not influence the temperature rise at the pulpal side of dentin during composite restoration of an occlusal preparation in a tooth. The amount and initial rate of temperature increase was most affected by the radiant exposure of the light curing unit. Within the limitations of this in vitro study, when irradiation time is constant, a curing light with higher radiant power can induce relatively high thermal transfer, thereby increasing the risk of pulpal damage.

Dynamic analysis of bulk-fill composites: Effect of food-simulating liquids

This study investigated the effect of food simulating liquids on visco-elastic properties of bulk-fill restoratives using dynamic mechanical analysis. One conventional composite (Filtek Z350 [FZ]), two bulk-fill composites (Filtek Bulk-fill [FB] and Tetric N Ceram [TN]) and a bulk-fill giomer (Beautifil-Bulk Restorative [BB]) were evaluated. Specimens (12 × 2 × 2mm) were fabricated using customized stainless steel molds. The specimens were light-cured, removed from their molds, finished, measured and randomly divided into six groups. The groups (n = 10) were conditioned in the following mediums for 7 days at 37°C: air (control), artificial saliva (SAGF), distilled water, 0.02N citric acid, heptane, 50% ethanol-water solution. Specimens were assessed using dynamic mechanical testing in flexural three-point bending mode and their respective mediums at 37°C and a frequency range of 0.1–10Hz. The distance between the supports were fixed at 10mm and an axial load of 5N was employed. Data for elastic modulus, viscous modulus and loss tangent were subjected to ANOVA/Tukey's tests at significance level p < 0.05. Significant differences in visco-elastic properties were observed between materials and mediums. Apart from bulk-fill giomer, elastic modulus was the highest after conditioning in heptane. No apparent trends were noted for viscous modulus. Generally, loss tangent was the highest after conditioning in ethanol. The effect of food-simulating liquids on the visco-elastic properties of bulk-fill composites was material and medium dependent.

Surface roughness and gloss of novel flowable composites after polishing and simulated brushing wear

Objective: To investigate surface properties of novel flowable composites after polishing and simulated brushing wear, compared to their pasty counterpart. Methods: Composites employed in this study were: three flowable composites (A1: Clearfil Majesty ES Flow; B1: Beautifil Flow Plus F00; C1: Filtek Bulk Fill) and three paste composites (A2: Clearfil Majesty; B2: Beautifil; C2: Filtek Z350. Eleven disk-shaped specimens were made for each material. The specimens were cured, then subjected to sandpaper finishing for 20 s, one-step polishing for 30 s, finally subjected to simulated brushing for 10 000 cycles. Surface roughness and glossiness were measured before finishing, after finishing, after polishing, after 5 000 brushing cycles and after 10 000 brushing cycles, respectively. Data obtained were analyzed using two-way ANOVA method. Scanning electron microscope was employed to examine the microscopic appearance of each material. Results: Surface roughness (0.11~0.22 μm) and glossiness (74.25~86.48 GU) of each material were similar after one-step polishing. After brushing simulation, roughness increased significantly and glossiness decreased significantly for each material (P<0.05). Group A1 presented the best gloss ([50.68±1.58] GU) after final wear (P<0.05). Flowable composites of group A1 and B1 tested in the present setup showed better surface properties compared to their pasty counterpart (group A2 and B2). Conclusions: Within the limit of this study, flowable composites tested in the present research can obtain similar surface polish or even better than the paste composite counterpart.

Load-Bearing Capacity of Direct Inlay-Retained Fibre-reinforced Composite Fixed Partial Dentures with Different Cross-Sectional Pontic Design

The load-bearing capacity and fracture pattern of direct inlay-retained FRC FDPs with two different cross-sectional designs of the ponticwere tested. The aim of the study was to evaluate a new fibre disposition. Two types of composites, Filtek Bulk Fill Posterior Restorative and Filtek Z250 (3M/ESPE, St. Paul, MN, USA), and one braided polyethylene fibre, Construct (Kerr, USA) were used. The results of the study suggested that the new tested disposition of the fibres prevented in some extend the delamination of the composite on buccal and facial sides of the pontic and increased the load-bearing capacity of the bridges.

Comparative Evaluation of the Depth of Cure and Degree of Conversion of Two Bulk Fill Flowable Composites.

Since the development of resin based composites, several improvements have been made to improve their physical and chemical properties. In an attempt to fasten and simplify the restoration process, a new class of resin based composite materials, called the bulk fill resin based composites have been introduced, which has been claimed to achieve a depth of cure of 4 mm without affecting the properties of the material. To comparatively evaluate the depth of cure of two different bulk fill flowable composite resins by ISO 4049 method and to evaluate the degree of conversion of the same composite resins with Fourier Transform Infrared (FTIR) spectroscopy method. Composite resin specimens (n=10) per group were prepared with bulk fill flowable composites, Surefil SDR flow (Dentsply Caulk, Milford, DE, USA) designated as Group A and Filtek bulk fill (3M ESPE, St.Paul, MN, USA) designated as Group B. Depth of cure was determined according to "ISO 4049; Depth of Cure" method, and FTIR spectroscopy method was used to estimate the degree of conversion of both the bulk fill flowable composites. The degree of conversion of monomer to polymer was estimated individually in coronal half (Group A1 and B1) and pulpal half (Group A2 and Group B2) by dividing each specimens into two halves. The data were analysed using Student's unpaired t-test at 5% level of significance. The mean depth of cure of Group A was 3.89 mm (±0.103) and for Group B was 3.54 mm (±0.129). The degree of conversion percentage for Group A1=78.51 (±47.8), Group A2= 31.9 (±22.4), Group B1=39.8 (±5.2), Group B2=37.4 (±6.4). Statistical analysis revealed significant difference in the depth of cure between the two bulk fill flowable composites with Group A higher than Group B. The degree of conversion of the coronal half of Group A1 was significantly higher when compared to Group B1. Surefil SDR bulk fill resin has better depth of cure and degree of conversion compared to Filtek bulk fill composites.

Effect of Staining Solutions on the Color Stability of Conventional and Bulk Fill Nanohybrid Resin Composites: A Spectrophotometric Analysis

ABSTRACT Aim This study is aimed to evaluate the effect of staining solutions on the color stability of bulk fill and conventional nanohybrid resin composites (RCs) when subjected to various immersion periods. Materials and methods A total of 120 cylindrical Teflon molds (4 × 4 mm) were obtained and divided into four groups of 30 each. Molds of groups I and II were filled with Tetric N Ceram Bulk Fill (Ivoclar Vivadent, Schaan, Liechtenstein) and Filtek Bulk Fill (3M ESPE, St. Paul, MN, USA). Molds of groups III and IV were filled with Tetric N Ceram (Ivoclar Vivadent) and Filtek Z250 XTE (3M ESPE) incremental fill RC. Photo-activation was performed and specimens were incubated. Spectrophotometer analysis was done according to Commission Internationale d'Eclairage Lab color scale. After taking the baseline measurements, 10 samples from each group were immersed in distilled water (control, subgroup a), tea (subgroup b), and coffee (subgroup c) respectively, for 1, 7, and 30 days. The color values of each specimen were remeasured and color change value (E*ab) was calculated after 1, 7, and 30 days. Data were analyzed by Friedman's test and Mann–Whitney U-test; p &lt; 0.05 is considered to be statistically significant. Results Group III specimens showed perceptible color changes at 30-day immersion period in coffee and tea. In group I specimens, color changes were perceptible at 7- and 30-day immersion periods in coffee and only 30-day immersion period in tea. Groups II and IV specimens showed perceptible color changes after all immersion periods in coffee and after 30 days in tea. Conclusion It can be concluded that Tetric N Ceram has less color change than the other nanohybrid RCs investigated when immersed in coffee and tea after various immersion periods. How to cite this article Thumu J, Kadiyala A, Bollu IP, Ballullaya SV, Devalla S. Effect of Staining Solutions on the Color Stability of Conventional and Bulk Fill Nanohybrid Resin Composites: A Spectrophotometric Analysis. J Oper Dent Endod 2017;2(1):1-5.

Surface characterization and mechanical behavior of bulk fill versus incremental dental composites

Aim: The aim of this study was to evaluate surface and mechanical properties of bulk fill composite compared to conventional incremental composites. Materials and methods: The bulk fill composites were Filtek Bulk Fill, Sonic Fill, SDR Smart Dentin Replacement and Tetric-N-Ceram Bulk Fill while the incremental ones were Filtek Z350 × T and Herculite XRV Ultra. Surface roughness and wettability was measured using profilometer (Bruker) and drop shape analyzer (Kruss), respectively. Surface hardness of the top and bottom surface was measured using Micromet 6040 (Buehler). For mechanical test, the universal testing machine was used under the three-point bending test. Results: There was no statistical significant difference in wettability and surface roughness between bulk fill and incremental composites, except the SDR that showed statistically significance higher roughness than incremental composites. All composites showed significantly lower hardness than Filtek Z350; the lowest hardness was recorded for SDR. There was no significant difference between bulk fill and incremental composites in flexure strength and modulus. SDR showed the lowest flexure strength and modulus but the highest strain% (P Conclusion: The difference between bulk fill and incremental composite is mainly material dependent.

Wear Resistance of Bulk-fill Composite Resin Restorative Materials Polymerized under different Curing Intensities

The aim of this study was to assess the wear resistance of four bulk-fill composite resin restorative materials cured using high- and low-intensity lights. Twenty-four samples were prepared from each composite resin material (Tetric N-Ceram, SonicFill, Smart Dentin Replacement, Filtek Bulk-Fill) resulting in a total of 96 samples; they were placed into a mold in a single increment. All of the 96 samples were cured using the Bluephase N light curing unit for 20 seconds. Half of the total specimens (n = 48) were light cured using high-intensity output (1,200 mW/cm2), while the remaining half (n = 48) were light cured using low-intensity output (650 mW/cm2). Wear was analyzed by a three-dimensional (3D) noncontact optical profilometer (Contour GT-I, Bruker, Germany). Mean and standard deviation (SD) of surface loss (depth) after 120,000 cycles for each test material was calculated and analyzed using one-way analysis of variance (ANOVA) with a significance level at p < 0.05. The least mean surface loss was observed for SonicFill (186.52 urn) cured using low-intensity light. No significant difference in the mean surface loss was observed when comparing the four tested materials with each other without taking the curing light intensity into consideration (p = 0.352). A significant difference in the mean surface loss was observed between SonicFill cured using high-intensity light compared with that cured using low-intensity light (p < 0.001). A higher curing light intensity (1,200 mW/cm2) had no positive influence on the wear resistance of the four bulk-fill composite resin restorative materials tested compared with lower curing light intensity (650 mW/cm2). Furthermore, SonicFill cured using low-intensity light was the most wear-resistant material tested, whereas Tetric N-Ceram cured using high-intensity light was the least wear resistant. The wear resistance was better with the newly introduced bulk-fill composite resins under low-intensity light curing.

Depth-of-cure of Bulk-fill Composites Cured in Tooth or Opaque Substrate

ABSTRACT Purpose To determine the effect of substrate on the depth-of-cure determination when using hardness profiles in a covered-slot technique and to introduce a new covered-slot method that uses tooth substrates. Materials and methods Three bulk-fill composites and one conventional composite were tested: Tetric EvoCeram Bulk Fill, Venus Bulk Fill, Filtek Bulk Fill Flowable, Filtek Supreme Ultra. The composites were light-cured in rectangular slots (2 mm deep, 2 mm wide) made in a plaster mold or an extracted tooth. The slots were covered with an orange glass plate during curing, leaving one end exposed for light-curing. After curing, the glass plate was removed and the sample was stored in the dark for 24 hours before Vickers hardness was measured as a function of depth at 0.5-mm intervals. Results were analyzed using two-way analysis of variance (ANOVA) and pairwise comparisons (significance level 0.05). Results The hardness of composites cured in covered-slot molds decreased with increasing depth (p &lt; 0.001). Bulk-filled composites cured in plaster molds had a slightly lower depth-of-cure than those cured in natural tooth substrates. Differences between the tooth and plaster substrates were significant at all depths in the “packable” bulk-fill composite (Tetric EvoCeram Bulk Fill), and were significant at ≥2.5 and ≥3.5 mm in the flowable bulk-fill composites (Filtek Bulk Fill Flowable and Venus Bulk Fill) respectively. Conclusion Using natural tooth substrates in the covered-slot method increased the depth-of-cure of bulk-filled composites in comparison to opaque plaster molds. How to cite this article Church BW, Tantbirojn D, Do T, Wells MH, Versluis A. Depth-of-cure of Bulk-fill Composites Cured in Tooth or Opaque Substrate. Int J Experiment Dent Sci 2017;6(2):68-73.

The effect of surface sealant application and accelerated aging on posterior restorative surfaces: An SEM and AFM study.

The purpose of this study was to evaluate the effect of surface sealant application and 10,000 thermocycles on the surface roughness and microhardness of different resin composite systems. A micro-hybrid (G Aenial Posterior), a nano-hybrid (Clearfil Majesty Posterior), a nano-fill (Filtek Ultimate Universal Restorative, Enamel Shade), and a bulk-fill resin composite (Filtek Bulk Fill Posterior Restorative) were used for the study. Specimens were evaluated at 24 h, after application of the surface sealant Fortify Plus, and after thermocycling. Data were analyzed using two-way repeated measures of analysis of variance (ANOVA) and a posthoc Bonferroni test (p<0.05). Surface roughness values of G Aenial Posterior and Filtek Ultimate Universal Restorative increased significantly after surface sealant application. However, neither surface sealant application nor thermocycling had a significant effect on composite microhardness values except Filtek Ultimate Universal Restorative (p>0.05).

Effect of Mouthwashes on Solubility and Sorption of Restorative Composites.

Objective Composites sorption and solubility can be precursors of several chemical and physical processes, which lead to deleterious effects on the polymer structure. This study evaluated the effect of mouthwashes on solubility and sorption of composite resins. Materials and Methods Forty-two specimens of each evaluated composite (Filtek Bulk Fill Flow, Opallis Flow, Durafill VS, and Filtek Z350) were prepared and randomized into seven groups for each solution (mouth rinses with and without alcohol and distilled water) and stored for seven days. Solubility and sorption tests were performed according to ISO4049. Data were analyzed using 2-way-ANOVA followed by Tukey's test for means comparison (α = 0.05). In addition, paired t-test was performed to analyze the alcohol effect on the studied composite resin properties. Results Listerine Cool Mint (containing alcohol in its composition) caused the greatest degree of sorption for all composites tested in comparison to other rinses, while for solubility this behavior was observed for Opallis Flow and Durafill VS composite resins (p < 0.05). Regarding the composites, Opallis Flow showed the highest sorption and solubility values in general (p < 0.05). Conclusion Overall, the sorption and solubility of composites were higher in mouthwashes containing alcohol in its composition, with Opallis Flow being the most affected composite resin.