Bulk Fill Research Articles

Evaluation of surface microhardness and gingival marginal adaptation of three different bulk-fill flowable resin composites: A comparative study.

To evaluate surface microhardness and gingival marginal adaptation of three different bulk-fill flowable resin composites (FB-RBCs) in Class V cavities with enamel or dentin margins before and after thermocycling (TMC). Three available FB-RBCs were used; Palfique Bulk Flow (PaBF) (Tokuyama Dental), SDR Flow+ Bulk Fill Flowable (Dentsply Sirona), and I-Flow Bulk Fill (I-Dental). Thirty discs were prepared from each type of FB-RBCs. The discs were subjected to Vickers microhardness tester machine. Class V cavities were prepared on 180 molars. Gingival margins of half the specimens were prepared above CEJ and the other half below CEJ. Cavities were restored with FB-RBCs for gingival marginal adaptation test. Two-way ANOVA was used in microhardness, while three-way ANOVA was used for marginal adaptation. The used materials showed statistically significant differences in microhardness and marginal adaptation. Regarding microhardness, PaBF showed the highest value before TMC and SDR was the highest after TMC. Regarding marginal adaptation, SDR revealed the best marginal adaptation than PaBF and I-flow, either subjected to TMC or not. The longevity of cervical restorations depend on both the location of the cavity margin and the material used. The microfractures in resin composite surface due to low surface microhardness as well as marginal gaps seen in laboratory studies could be considered as an indicative parameter for clinical problem associated with marginal differences.

Clinical performance of different bulk-fill composite resin systems in class II cavities: A 2-year randomized clinical trial.

This study evaluated the clinical performance of bulk-fill resin composite systems with different viscosities in class II cavities. A total of 80 class II restorations were performed with a single operator in 50 patients using four different bulk-fill resin composite materials: Filtek™ Bulk Fill, Heated Filtek™ Bulk Fill, G-ænial™ BULK Injectable, and SonicFill3. A double-blinded randomized clinical trial was designed to evaluate the two-year clinical performance of the four bulk-fill composite resins using modified FDI criteria. Data were analyzed descriptively. Level of significance was set at 0.05. Differences between groups were tested using Wilcoxon-signed-rank and Mann-Whitney-U test as nonparametric tests. Data were analyzed using Kruskal-Wallis, Mann-Whitney U, and Wilcoxon signed rank tests (p < 0.05). Eighty restorations were available for evaluation, with a survival function of 100%. No statistically significant differences were observed between the four groups regarding assessing esthetic, functional, and biological properties during different follow-up periods. After 2 years of clinical follow-up, the bulk-fill composite systems with different viscosities seem to be esthetically, functionally, and biologically acceptable, with a promising clinical performance in class II cavities.

Clinical evaluation of posterior restorations over wet and dry dentin using an etch-and-rinse adhesive: A 36-month randomized clinical trial

ObjectivesTo evaluate the clinical performance of posterior restorations over wet and dry dentin with an etch-and-rinse adhesive after 36 months of clinical service. MethodsForty-five participants were recruited, each one had at least two posterior teeth that needed restoration. Ninety restorations were placed on Class I or Class II cavities. For the restoration protocol, a simplified etch-and-rinse adhesive (Adper Single Bond 2) was applied over wet (WD) or dry dentin (DD) and later restored with a bulk-fill composite (Filtek Bulk Fill) under rubber dam isolation. Each restoration was evaluated using the World Dental Federation (FDI) criteria after 6, 12, and 36 months of clinical service, regarding the following principal restoration characteristics: postoperative sensitivity, marginal discoloration, marginal adaptation, fracture of material and retention, and recurrence of caries. Kruskal Wallis analysis of variance rank (α = 0.05) and Kaplan-Meier survival analysis were used for statistical analysis. ResultsAfter 36 months of clinical evaluation, no significant difference between groups was observed in each FDI criterion (p > 0.05). Twenty restorations (WD=10, DD=10) showed minor marginal staining, and twenty-two restorations (WD=11, DD=11) presented small marginal adaptation defects (p > 0.05). Four restorations were lost (WD = 2, DD = 2) and the fracture rates (95% confidence interval) were 94.9% for each one, without significant difference between wet and dry dentin (p > 0.05). SignificanceThe degree of dentin moisture does not seem to affect the clinical performance of a simplified etch-and-rinse adhesive in posterior restorations when the adhesive is applied vigorously over the dentine surface.

Repair of monolithic zirconia restorations with different direct resin composites: effect on the fatigue bonding and mechanical performance

ObjectiveThe study aims to evaluate the shear bond and flexural strength fatigue behavior of yttrium-stabilized zirconia (4YSZ) repaired using different resin composites.Materials and methodsCylindric specimens of 4YSZ were obtained for the bond strength (Ø = 6 mm, 1.5 mm of thickness) and biaxial flexural strength (Ø = 15 mm, 1 mm of thickness) fatigue tests and divided into 3 groups according to the repair resin composite: EVO (nanohybrid), BULK (bulk-fill), and FLOW (flowable). The zirconia surface was air-abraded with alumina particles, a 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) primer was applied, and the resin composite was build-up over the zirconia. Fatigue shear bond strength and flexural fatigue strength tests were performed (n = 15). One-way ANOVA and Tukey post hoc tests were carried out for both outcomes, besides scanning electron microscopy and finite element analysis.ResultsThe repair material affected the fatigue shear bond strength of zirconia ceramic. The BULK group (18.9 MPa) depicted higher bond strength values than FLOW (14.8 MPa) (p = 0.04), while EVO (18.0 MPa) showed similar results to both groups. No effect was observed for the mechanical behavior (p = 0.53). The stress distribution was similar for all groups.ConclusionThe repair of yttrium-stabilized zirconia (4YSZ) ceramics with bulk-fill resin composites was the best option for high fatigue bond strength. However, the fatigue mechanical performance was similar regardless of the applied repair material.Clinical relevanceThe repair of yttrium-stabilized zirconia (4YSZ) monolithic restorations may be performed with nanohybrid and bulk-fill resin composites in order to promote longevity in the treatment.

Two-year clinical performance of dual- and light-cure bulk-fill resin composites in Class ӀӀ restorations: a randomized clinical trial

ObjectiveThis study aimed to compare the clinical performance of dual- and light-cure bulk-fill resin composites (BFRCs) in Class ӀӀ restorations after 2 years.Materials and methodsA double-blinded, prospective, randomized clinical trial (RCT) was conducted following the CONSORT (Consolidated Standard of Reporting Trials) guidelines. Forty patients were enrolled in the study. Each patient received three compound Class ӀӀ restorations. One dual-cure (Fill-Up; Coltene Waledent AG) and two light-cure (QuiXfil; Dentsply, and Tetric N-Ceram Bulk Fill; Ivoclar Vivadent) BFRCs were used for 120 Class ӀӀ restorations. A universal adhesive (ONE COAT 7 UNIVERSAL; Coltene Waledent AG) was used with all restorations. Restorations were clinically evaluated after 1 week (baseline), 6 months, 12 months, 18 months, and finally after 24 months using the FDI World Dental Federation (FDI) criteria. The Kruskal–Wallis test was used for comparison between BFRCs groups at baseline and at each recall period, and the Wilcoxon signed-rank test was used for comparing different follow-up times of each BFRC to baseline. The level of significance was set at p < 0.05.ResultsAll BFRCs restorations showed only minor changes and revealed no statistically significant differences between their clinical performance for all evaluated parameters at all recall periods; also, there was no statistically significant difference between all recall periods and baseline for all evaluated parameters.ConclusionThe two-year clinical performance of dual-cure BFRC was comparable to light-cure BFRCs in Class ӀӀ restorations.Clinical relevanceDual- and light-cure BFRCs showed excellent clinical performance in Class ӀӀ restorations after a 2-year clinical follow-up.

Physicochemical and mechanical properties of preheated composite resins for luting ceramic laminates.

This study analyzed and compared the physicochemical and mechanical properties of preheated resin composite with light-cured resin cement for luting indirect restorations. 210 specimens of resin cement/resin composite were prepared according to preheating treatment heated (Htd) or not (NHtd). Light-cured resin cement (Variolink Veneer, Ivoclar), and resin composite (Microhybrid-Z100, 3M; Nanohybrid-Empress direct, Ivoclar; and Bulk fill-Filtek One, 3M) were used (n = 10). Resin cement specimens were not preheated. The response variables were (n = 10): film thickness, microhardness, liquid sorption and solubility. Data were analyzed by 2-way ANOVA and Tukey HSD post-test (α = 0.05). Bulk fill NHtd resin had the highest film thickness values (p < 0.001). Microhybrid and nanohybrid Htd resins had the smallest thicknesses and did not differ from the cement (p > 0.05). The highest microhardness values were found for Bulk fill NHtd and Bulk fill Htd resins. The nanohybrid and microhybrid Htd resins showed the lowest microhardness values, with no difference in cement (p > 0.05). For liquid sorption, there was no significant difference between the groups (p = 0.1941). The microhybrid Htd resin showed higher solubility values than the other materials (p = 0.0023), but it did not differ statistically from resin cement (p > 0.05). Preheating composite resins reduced the film thickness. After heating, nanohybrid and Bulk fill resins retained stable microhardness, sorption, and solubility values.

A Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth Using Different Post-Obturation Restorative Materials: An In Vitro Study

ABSTRACT This in vitro study was conducted to evaluate and compare the fracture resistance of endodontically treated teeth using different post-obturation restorative materials. Seventy-five non-carious extracted human teeth were collected. Access opening, chemicomechanical preparation, and obturation were done. Teeth were randomly divided into various groups depending on the type of post-endodontic restoration: group I—control group, group II—Tetric-N-Flow Bulk Fill, group III—Tetric-N-Flow Bulk Fill + everX Posterior, group IV—P60, and group V—P60 + everX Posterior. The fracture resistance of each sample was measured using the universal testing machine. Results: The results obtained were subjected to statistical analysis. This demonstrated that group III (Tetric-N-Flow Bulk Fill + everX Posterior) was shown to be the most effective group followed by group V (Filtek P60 + everX Posterior) out of all of the other restorative experimental groups. Conclusion: Tetric-N-Flow Bulk Fill + everX Posterior showed maximum fracture resistance among the experimental groups.

Evaluation of fracture resistance of maxillary premolars of different geometrical cavities restored with different composite resins incorporated with chitosan nanoparticles.

Composites with 0.2% chitosan nanoparticles (CSN) are used recently; however, this combination needs to be studied in different cavity designs. The aim of the study was to compare the fracture resistance of maxillary premolars with different cavity geometries restored with different types of composite resins incorporated with 0.2% CSN. About 130 extracted human single-rooted maxillary premolars were embedded in acrylic molds 2 mm below cementoenamel junction, divided into five groups for cavity preparations of standardized dimensions. Group 1: (control) intact teeth (n = 10), Group 2: Class I cavities (n = 40), Group 3: Class II mesio-occlusal (MO) (n = 40), Group 4: Class II mesio-occluso-distal (MOD) (n = 40). Groups 2, 3, and 4 were subdivided into four subgroups for composite restoration; A: Neo spectra ST-Universal (NST); B: Tetric N-Ceram Bulk-fill (TNC); C: NST + CSN; and D: TNC + CSN and tested for fracture resistance using universal testing machine. One-way analysis of variance and post hoc Tukey's tests were used for data analysis (P ≤ 0.05). In all groups, the highest fracture resistance was found in MOD cavities, followed by MO and least in Class I cavities. Subgroup D (TNC with CSN) showed the highest fracture resistance in all groups (P ≤ 0.05). Tetric N-Ceramic bulk fill with 0.25% CSN showed high fracture resistance in cavities with different geometries.

Effect of Staining Beverages on Color Stability of Composite: A Spectrophotometric Study

ABSTRACT Objective: This study used spectrophotometry to examine how staining beverages affect the color stability of three commercial composite materials (nanohybrid composite (A), bulk fill composite (B), and flowable composite (C)) over time. Materials and Methods: Composite discs were randomly divided into groups. The specimens were kept in coffee, tea, red wine, and cola for 14 days at 37°C in the dark. At baseline, 7 days, and 14 days, spectrophotometers measured color. Calculated and analyzed color differences (E). Results: Staining beverages changed the color of all composites. Composite material A had the best color stability, whereas material C stained beverages the most. Red wine and coffee discolored composites most. Discoloration increased over the 14-day immersion period. Conclusion: Composite materials with better color stability were material A. Red wine and coffee discolored composites most. When choosing restorative materials, dentists should consider composite materials’ color stability for long-lasting, visually acceptable results.

One-year radiographic and clinical performance of bioactive materials in primary molar pulpotomy: A randomized controlled trial

ObjectivesMineral Trioxide Aggregate (MTA) is considered the gold standard material for pulpotomy procedures. However, some drawbacks such as poor handling and long setting time are challenging when it is used as pulpotomy dressing in primary molars in children. Hence, the purpose of this study was to compare the radiographic and clinical performance of a premixed, fast setting bioceramic root repair material (BC RRM-F) with MTA in vital pulpotomy procedures of primary molars, with or without the added seal of a stainless steel crown (SSC). MethodsIn this double blinded, four-arm, parallel group randomized contolled trial (RCT), 64 primary molars were randomly allocated to one of the four treatment groups: MTA (PDTM MTA WHITE)+SSC, MTA+GI (bulk fill glass ionomer with glass hybrid technology GC EQUIA Forte® HT), BC RRM-F+GI and BC RRM-F+SCC. All molars were evaluated clinically and radiographically according to the modified Zurn and Seale criteria at 1, 3, 6, and 12 months follow up. Multivariate cox regression models and Kaplan-Meier curves were used for survival analysis. ResultsThere was no statistically significant difference between the success of both pulp capping materials used. Overall survival analysis showed that using GI instead of SCC as a final restorative material was significantly associated with increased risk of failure. ConclusionsTotalFill® BC RRM™ Fast Set Putty can be used as an alternative to MTA in primary molar pulpotomy. Regardless of the pulp capping material, one year survival of pulpotomized primary molars restored with SSC is higher compared to those restored with GC EQUIA Forte® HT. Clinical SignificanceClinicians’ preference and cost effectiveness may justify the use of either material in primary molar pulpotomy. Parents insisting on tooth-colored restorations for their children's pulpotomized teeth cannot be told that the expectation for success is the same as those restored with SSC, even if calcium silicate-based pulp capping materials are used.

Effect of duration and infection control barriers of light curing unit on hardness of Bulk Fill composite resin.

This study aimed to investigate the impact of the duration of light curing unit (LCU) usage and the use of infection control barriers on the hardness of Bulk Fill composite resin after curing. The hypotheses were that extended usage of the LCU would not reduces its output power and resin hardness, and that the presence of polyethylene film barriers exacerbates the reduction in resin hardness. Based on the absence or presence of polyethylene film (PE) and the number of layers used, a 3M LED curing light (EliparTM DeepCure-S; 3M ESPE, St Paul, MN, USA) was divided into three groups: PE0, PE1, and PE3. The curing light was used 30 times daily for 20 s per exposure, at frequencies of 0, 6, and 12 months. Maximum output power tests were conducted for each group of curing lights. Custom-made plastic modules were used to stack Bulk Fill composite resin (Filtek Bulk Fill Posterior Restorative; 3M ESPE) to a thickness of 4 mm. Each group of curing lights was used to cure the modules in a direct contact manner for 20 s. Vickers hardness measurements were taken at the top and bottom surfaces of the resin specimens using a digital microhardness tester. A one-way or two-way ANOVA analyzed the power of LCUs, Vickers hardness of Bulk Fill composite resin, and hardness decrease percentage across groups. Pairwise comparisons used the Tukey test (α = 0.05). As the duration of usage increased, both the power of the curing light and the hardness of the resin significantly decreased. Significant differences were observed in power and resin hardness among the PE0, PE1, and PE3 groups. When the duration of usage was 6 months or less, only multi-layered PE films led to a significant increase in the percentage decrease of hardness of cured resin from top to bottom. However, at 12 months, both single-layer and multi-layered PE films resulted in a significant increase in the percentage decrease of hardness of cured resin from top to bottom. The output power of the light curing unit decreases with prolonged usage, thereby failing to meet the curing requirements of Bulk Fill composite resin. The use of single-layer PE as an infection control barrier is recommended.

Pre-heating decreases micro-leakage of bulk fill composite resins in dentin margins of class II cavities: an in-vitro study

Pre-heating decreases micro-leakage of bulk fill composite resins in dentin margins of class II cavities: an in-vitro study

Short curing time bulk fill composite systems: volumetric shrinkage, degree of conversion and Vickers hardness.

This study aimed to evaluate volumetric polymerization shrinkage, degree of conversion and Vickers hardness of four bulk-fill resin composites light-activated with their dedicated light curing units (LCUs). Four groups were evaluated, according to the type of composite and curing mode: Tetric EvoCeram Bulk-fill (TEBO) and Tetric EvoFlow Bulk-fill (TEBF) were light-activated with Bluephase Style 20i (20s, in high-mode), while Tetric Powerfill (TEPO) and Tetric Powerflow (TEPF) were light-activated with Bluephase PowerCure (3s). Volumetric polymerization shrinkage test (n = 6) was performed in standardized box-shaped class-I cavities of extracted third molars (4 x 4 x 4 mm). Teeth were scanned before and after resin composite application by micro-computed tomography, and acquired data were evaluated with Amira software. Degree of conversion (n = 5) was evaluated at the top and bottom surfaces of composite cylindric samples (4 mm diameter, 4 mm thickness) using an FT-IR spectrometer (spectra between 1,500 and 1,800 cm-1, 40 scans at a resolution of 4 cm-1). Three Vickers indentations (50 g / 15 s), spaced 500 μm apart, were performed on the top and bottom composite surfaces and averaged. One-way ANOVA was used for data evaluation. TEPF showed the lowest volumetric polymerization shrinkage (p < 0.05), while the other composites were not significantly different within each other (p > 0.05). All materials presented a significant decrease in degree of conversion and Vickers hardness when compared top to bottom surfaces (p < 0.05). Bottom to top surface ratios for degree of conversion ranged from 0.8 (TEBO and TEPO) to 0.9 (TEBF and TEPF), and from 0.4 (TEPO) to 0.7 (TEBF and TEPF) for hardness. In conclusion, resinous materials present a decrease in hardness and degree of conversion from top to bottom even when a higher power is used, while the flowable material TEPF showed the lowest volumetric shrinkage values compared to the other materials.

Comparative study of physical-chemical properties of bioactive glass ionomer cement.

This study analyzed the physical-chemical properties of bioactive ionomer materials. Cention N bioactive materials were evaluated chemically activated (CN) and light-cured (CN-LC), Equia Forte Fill (EQUI); conventional resin composite Filtek Z350 XT (Z350); resin glass ionomer cement Riva light Cure (RIVA) and flowable resin composite Filtek Bulk Fill Flow (BULK-F) were evaluated. Sixty specimens (n=10) were prepared for sorption (SR), solubility (SL), flexural strength (FS), shrinkage stress (SS), conversion degree (CD), microhardness (MI), and surface roughness (SR) tests. Non-cured and light-cured materials were assessed on FTIR. 30 human molar teeth were used in the bond strength test (BS). Data were subjected to ANOVA and post-hoc Tukey's test (5% of significance). EQUI showed more sorption in SR and no statistical difference from RIVA and CN-LC. CN group showed more solubility and EQUI presented less (p<0.05). BULK-F showed higher FS (MPa), without differences from CN and Z350, whereas EQUI presented the lowest FS not differing from RIVA. BULK-F and CN-LC showed more shrinkage stress differing from EQUI. CN-LC and CN showed higher CD differing from the other which showed no differences (p>0.05) between them. EQUI showed the highest hardness (p<0.05) in MI. There were no differences (p>0.05) in SR (µm). Z350 and BULK-F presented higher BS, whereas CN-LC showed the lowest, although not differing from EQUI and RIVA. Equia Forte's solubility and microhardness make it a good alternative as a restorative material. Cention N degree of conversion and flexural strength making it an esthetic option to amalgam.

Comparison of Marginal Seal and Tensile Bond Strength of an Alkasite, Zircomer, and Bulk Fill Composite to Carious Affected Primary Molars

Assessment of the micro tensile bond strength (μTBS) and microleakage of contemporary restorative materials (Cention N cement (CN), Bulk-fill Resin-based composite (BF-RBC), and Zirconomer Improved) bonded to carious affected dentin (CAD) of primary molars as compared to conventional control Glass ionomer cement (GIC). Eighty human primary molars having scores 4 and 5 of the International Caries Detection and Assessment System (ICDAS) were included. Specimens were randomly allocated into four groups (n = 20) Group I = GIC, Group 2: Zirconomer Improved, Group 3: CN, and Group 4: BF-RBC. All the samples were thermocycled followed by marginal leakage, μTBS, and failure mode assessment using a dye penetration test, universal testing machine, and a stereomicroscope. The μTBS and microleakage results were examined using (ANOVA) and Tukey post hoc tests. Samples from Group 1 (GIC) revealed the highest value of marginal leakage (30.55±10.31 nm) and the lowest recorded value of μTBS (12.28±0.32 MPa). In contrast, the specimens from Group 3 (CN) demonstrated the lowest levels of microleakage (14.89±4.33 nm) and highest bond integrity (18.12±0.79 MPa). Cention N cement and Bulk-fill composite have shown to be reliable options as a restorative material in primary dentition due to their superior tensile bond strength and reduced marginal leakage scores when applied to caries-affected dentin.

Alkasite restorative material for endodontically treated teeth: a randomized controlled pilot study.

This study aimed to evaluate the clinical performance of an alkasite restorative material in molars that had undergone root canal treatment. The research was registered in Brazilian Registry of Clinical Trials. The randomized clinical trial involved 33 patients, each with at least 1 mandibular molar requiring restoration after receiving endodontic treatment. Patients were randomly assigned to receive either bulk-fill resin composite (Tetric N Ceram Bulk Fill, Ivoclar Vivadent) or the alkasite restorative material (Cention N, Ivoclar Vivadent). Upon completion of the restorations, 3 calibrated professionals utilized the United States Public Health Service criteria to assess various factors, including retention, secondary caries, marginal adaptation, restoration color, marginal pigmentation, and anatomical form. Evaluations were conducted at intervals of 7 days, 6 months, and 17 months. Additionally, the assessment encompassed the presence of radiolucent lines adjacent to the restoration, material deficiencies or excess, contact points, and caries recurrence. The data underwent analysis using the Friedman and Mann-Whitney tests (α = 0.05). After 17 months, the results revealed that the alkasite restorative material exhibited greater wear of anatomical shape compared to the bulk-fill resin composite (p = 0.0189). Furthermore, the alkasite restorative material significantly differed from the natural tooth color in most cases (p = 0.0000). However, no other criteria displayed significant differences between the materials or over time (p > 0.05). The alkasite restorative material (Cention N) emerges as a viable option for restoring endodontically treated teeth, displaying clinically acceptable alterations after a 17-month evaluation period. Brazilian Registry of Clinical Trials (ReBEC) Identifier: RBR-97kx5jv.

Abrasive resistance and microhardness of self-adhesive (Surefil one) and conventional bulk fill composites: An- in vitro study.

Aims and objectives: To evaluate abrasive resistance and microhardness of self-adhesive Surefil one and conventional bulkfill composites Beautifil bulk restorative and Filtek one bulk fill restorative. Materials and Methods: For the abrasive resistance test, thirty composite discs (4 mm hieght×8 mm width) in each group (n=10) were fabricated. GI: Beautifil bulk restorative, GII: Filtek One Bulk fill restorative and GIII: Surefil one self-adhesive. By placing the material in a mold in a single increment then curing. A custom-made toothbrush simulator was employed for wear testing. The samples weighted before and after the brushing to measure the weight loss. For the microhardness test, thirty cylindrical specimens (6 mm× 8 mm) (n= 10) were fabricated to assess the microhardness, top and bottom surfaces were tested using Vicker Hardness test. The results were analyized with a one-way ANOVA test, the post-hoc comparisons were examined in Tukey test. Results: Abrasive Resistance results, Surefil one (9.52gr) and Beautifil bulk (4.16gr) showed an increase in weight after brushing, while Filtek one bulkfill (-0.85gr) showed a decrease in weight.Microhardness test results, Beautifil bulk showed the highest number of VH (74.83) followed by Surefil one (70.61) and Filtek one bulkfill (62.95). Conclusion: Beautifil bulk was more resistant to abrasion in comparison to Surefil one self-adhesive and One bulk fill. The great weight loss was observed in One bulk fill. Great weight gain was observed in Surefil one self-adhesive. Beautifil bulk showed the highest VH number compare to Surefil one self-adhesive and One bulk fill. Filtek one bulk fill showed low resistance and low hardness number. Keywords: Bulk fill, Self-adhesive, Abrasive resistance, Microhardness Composite, Surefil one

Effect of repeated preheating on monomer elution from a bulk-fill composite resin.

Due to incomplete polymerization of composite resin restorations, residual monomers adversely affect their mechanical properties and biocompatibility. Preheating of composite resins is advised to increase the degree of conversion and reduce monomer elution. This study aimed to analyze the effect of preheating and repeated preheating on the amount of monomer released from a bulk-fill composite resin. Forty samples were prepared using Filtek One Bulk Fill Restorative composite resin. Samples in one group were fabricated at room temperature, whereas the composite resins in the other groups were cured after 1, 10, or 20 repeated preheating cycles (55 °C), 10 in each group. Eluted urethane dimethacrylate (UDMA) and bisphenol-A-glycidylmethacrylate (BisGMA) monomers were measured with high-performance liquid chromatography (HPLC) 24 hours and 30 days after immersion. The data were evaluated using one-way ANOVA and post hoc Tukey tests. Paired-sample t tests were used to test the differences between time intervals. At both time intervals, the greatest amounts of released BisGMA, UDMA, and total monomers were obtained from the control group, whereas 10 preheating cycles resulted in the least monomer elution. The decrease in monomer elution was not statistically significant after 10 preheating cycles compared with that after one preheating cycle (P>0.05). The group with 20 preheating cycles showed a greater amount of monomer elution compared to that with 1 and 10 cycles, which was statistically significant (P < 0.05). The amount of released monomers on day 30 was significantly higher than on day 1 (P<0.01). Preheating of the bulk-fill composite resin was shown to be effective in reducing monomer elution. However, monomer elution was adversely affected after repeated preheating cycles of 20.

The Effect of Layer Thickness and Light Intensity on the Degree of Conversion, Microhardness and Cytotoxicity of Bulk Fill Composite Resins

Objectives: The aim of this study was to evaluate the effects of polymerizing bulk fill composite resins at different thicknesses and different light intensities on the degree of conversion, microhardness and cytotoxicity of the composites. &#x0D; Methods: Two different bulk fill composite resins were used in this in vitro study: Sonic Fill 2, Filtek Bulk Fill. Samples prepared from both composites with a thickness of 2, 4 and 6 mm were polymerized in 2 different power modes. The degree of conversion, microhardness and cytotoxicity of these samples were measured.&#x0D; Results: As the layer thickness of the bulk fill composite resins increased, the degree of conversion of the lower surfaces of the composites decreased significantly (p

Effect of Curing Mode on Color Change of Two Different Bulk Fill Composites

Amaç: Bu çalışmanın amacı iki farklı kürleme modunda ışıklanan iki farklı bulk fill kompozit rezinin, 1 hafta boyunca distile su, şarap ve kahvede bekletilmesiyle meydana gelen renk değişimlerinin değerlendirilmesidir. &#x0D; Gereç-Yöntemler: Bu çalışmada A2 renginde iki farklı bulk fill kompozit rezin kullanılmıştır: Sonic Fill 2 (SF) (Kerr, ABD) ve Filtek Bulk Fill (FBF) (3M ESPE, ABD). Örnekler 5 mm çapında, 2 mm kalınlığında bir teflon kalıp kullanılarak hazırlanmıştır. Örnekler bir LED ışık cihazı (VALO Ultradent, South Jordan, UT) ile iki farklı kürleme modunda (standart güç modu-1000 mw/cm²-20 sn ve ekstra güç modu 3200 mw/cm²-3 sn) polimerize edilmiş, toplam 60 numune hazırlanmıştır. Renklendirme işlemlerine başlamadan önce örneklerin renk değerleri spektrofotometre (VITA Easyshade V, VITA Zahnfabrik, Almanya) kullanılarak ölçülmüştür. Ardından örnekler, üç farklı sıvıda 1 hafta boyunca bekletilmiştir. Renklendirme işlemleri tamamlandıktan 24 saat sonra renk ölçümü tekrarlanmıştır. Renk değişimi değerlendirmesi CIEDE2000 formülü kullanılarak yapılmıştır. Çalışmada elde edilen veriler SPSS Windows 25.0 (SPSS Inc., Chicago, IL, USA) programı kullanılarak analiz edilmiştir. Anlamlılık düzeyi p