Filtek Bulk Fill Research Articles (Page 1)

BackgroundSurface microhardness (SM) is a desirable property of any restorative material because it allows it to resist masticatory forces and any chemical challenges encountered in the oral environment. Therefore, the aim of this study was to evaluate the in vitro surface microhardness of three Bulk Fill resins previously exposed to five types of carbonated beverages at different times.MethodsThis in vitro experimental study consisted of resin composite discs (n = 180), distributed in three groups: Tetric N-Ceram Bulk-fill, Opus Bulk Fill APS and Filtek Bulk Fill, each immersed in distilled water (control), Fanta®, Sprite®, Coca-Cola®, Inca-Kola® and Pepsi®. Surface microhardness was measured before and after immersion in beverages for 1 day and 7 days. Data were subjected to statistical analysis using Games Howell’s robust ANOVA with post hoc and Friedman’s test with Bonferroni’s post hoc. Statistical significance was set at p < 0.05.ResultsAfter 1 day of immersion, the Tetric N-Ceram Bulk Fill resin significantly decreased its surface microhardness after immersion in Fanta, Sprite, Coca-Cola, Inca-Kola and Pepsi (p < 0.05), while the Filtek Bulk Fill resin significantly decreased its SM after immersion in Pepsi and Sprite (p < 0.05); however, the Opus Bulk Fill resin showed no significant SM differences (p = 0.141). On the other hand, after 7 days of immersion, the three Bulk Fill resins significantly decreased their SM, compared to the control group (p < 0.001), after being immersed in the five carbonated beverages. Finally, distilled water did not significantly affect the surface microhardness of the three Bulk Fill resins over time (p < 0.05).ConclusionThis study highlights the susceptibility of Bulk Fill resin composites to acidic degradation caused by carbonated beverages. While short-term exposure resulted in variable effects depending on the resin type, prolonged immersion consistently led to a reduction in surface microhardness across all materials tested. These findings suggest that the chemical composition of each resin influences its resistance to erosive challenges. Although this is an in vitro study, the results may provide a basis for future investigations into how acidic diets could influence the long-term performance of Bulk Fill composites in the oral environment.

Effect of pick-up material and hole diameter on the flexural strength of milled polymethyl methacrylate complete arch implant-supported interim prostheses.

ObjectiveThis study aimed to assess the color stability of a novel self-cure bulk-fill composite (automix and capsule forms), in comparison to a light-cure bulk-fill composite and a conventional flowable composite after immersion in common beverages.Materials and methodsFour composite resins (Stela Automix, Stela Capsule, Filtek Bulk Fill Flowable, and G-ænial Universal Injectable) were evaluated on 160 disc-shaped specimens. Specimens were randomly assigned to four subgroups (n = 10) and immersed in tea, coffee, cola, or distilled water (control). Color measurements were performed using a spectrophotometer at baseline, 6 and 12 days, and color changes (ΔE₀₀) were calculated using the CIEDE2000 formula. Statistical analyses were performed using one-way ANOVA with Tukey’s post-hoc tests and paired sample T-tests to evaluate time-dependent changes (p < 0.05).ResultsAll composites showed increased discoloration over time, with coffee causing the most significant color change, followed by cola, while tea had a milder effect. Self-cure bulk-fill composites showed significantly higher ΔE₀₀ values than their light-cure composites. Stela Automix showed the greatest color change after Stela Capsule.ConclusionThe results suggest that self-cure bulk-fill composites have lower color stability than light-cure composites. Filler characteristics, particularly particle size and loading, have a greater influence on color stability than resin matrix composition.

Aim: This study aimed to evaluate and compare the average pores size and closed porosity levels in different types of resin composites using micro-computed tomography (micro-CT).Materials and methods: Ninety specimens (2.5 mm × 4 mm × 4 mm) were prepared using 15 different materials divided into 15 groups (n = 6/group). Groups were either conventional packable (Filtek Universal Restorative and G-aenial A'chord), conventional flowable (CLEARFIL MAJESTY ES Flow, G-aenial Flo X, and G-aenial Universal Injectable), bulk fill flowable (SDR flow+ and Filtek Bulk Fill Flowable Restorative), dual-cure (Gradia Core and CLEARFIL DC Core Plus), or fiber-reinforced composites (Nova Pro Flow, Fibrafill DENTIN, everX Flow with either Dentin or Bulk shade, and everX Posterior), in addition to one glass hybrid material (EQUIA Forte HT Fil). All specimens were scanned using a micro-CT machine (Bruker Skyscan 1272), and analyzed for the average size, volume percentage, and distribution of closed porosities. Data was analyzed using Shapiro–Wilk for normality, followed by two-way ANOVA with Tukey's HSD for group comparisons. Pearson correlation assessed the relation between the average size and the percentage of closed pores.Results: The results revealed significant differences in closed porosity levels among the tested groups. Filtek Universal Restorative exhibited the lowest porosity (0.049%), while Fibrafill DENTIN had the highest (4.78%) and the largest average pore size (0.996 mm³). In contrast, A'chord had the smallest average closed pore size (0.017 mm³) (p < 0.05). When the composites were categorized into flowable and packable variants, a significant difference (p < 0.05) was observed in the average percentage of closed pores, with flowable composites showing a lower porosity (0.31%) compared to packable composites (1.25%).Conclusion: The findings highlight the influence of material type on porosity formation, with larger pore sizes correlating with higher closed porosity percentages.

Background: This study aimed to evaluate the effect of layer thickness on the conversion degree and microhardness of low- and high-viscosity bulk-fill composite resins. Methods: Six different bulk-fill composite resins, SDR (Dentsply), Sonic Fill (Kerr), X-tra Fil (Voco), Beautifil Bulk Restorative (Shofu), Beautifil Bulk Flowable (Shofu), and Filtek Bulk Fill Flowable (3M ESPE) were tested. Disc-shaped samples (7 mm diameter, 2 and 4 mm thickness, n=4 per group) were prepared and polymerized using an LED (Light-Emitting Diode) curing unit (Elipar S10, 3M ESPE). After 24 hours at 37°C, the degree of conversion was analyzed using Fourier Transform Infrared Spectroscopy (FTIR)- Attenuated Total Reflectance (ATR) (Perkin Elmer Spectrum Two), and microhardness was measured using a Knoop hardness tester (Buehler MMT-3 Digital Microhardness Tester). Data were analyzed using Shapiro-Wilk, ANOVA, Tukey’s HSD, and Pearson correlation with SPSS 26.0V (IBM SPSS Corp.; Armonk, NY, USA). Results: No significant difference in bottom/top surface hardness ratio was observed in 2 mm samples (P &gt; .05). However, at 4 mm, a statistically significant difference was found among the composite groups (P= .003). SDR had the highest hardness ratio (0.87 ± 0.04), while Beautifil Bulk Restorative (BBR) had the lowest (0.68 ± 0.08). The highest degree of conversion at both thicknesses was in SDR (65.13 ± 2.00 at 2 mm, 62.90 ± 2.30 at 4 mm), whereas X-tra Fil had the lowest (41.25 ± 13.57 at 2 mm, 39.25 ± 6.75 at 4 mm). In BBR, conversion at 2 mm was significantly higher than at 4 mm (P=.004). Cite this article as: Kütük Ömeroğlu M, Ertaş E. Effect of layer thickness on conversion degree and microhardness of bulk-fill composites. Essent Dent. 2025; 4, 0024, doi: 10.5152/EssentDent.2025.25024.

Background. Physicomechanical properties and clinical service of bulk-fill composites depend on their adequate polymerization and depth of cure. Some manufacturers claim that these composites can be adequately cured when used in bulks exceeding 4 mm. Objective. The aim of this study was to compare Vickers microhardness (VMH) and depth of cure (DOC) of six contemporary bulk-fill resin composites at depths of 4 mm and 6 mm. Material and methods. Six bulk-fill composites were evaluated in this study: 1. Tetric EvoCeram Bulk (Ivoclar Vivadent, Schaan, Liechtenstein), (TEC); 2. Filtek Bulk Fill Posterior (3M ESPE Dental Products Division, St. Paul, MN, USA), (FBF); 3. Filtek One Bulk Fill (3M ESPE Dental Products Division, St. Paul, MN, USA, (FOB); 4. SonicFill 2 (Kerr, Orange, CA, USA), (SF2); 5. Admira Fusion X-tra (Voco, GmbH, Cuxhaven, Germany), (AFX); 6. GrandioSO X-tra (Voco, GmbH, Cuxhaven, Germany), (GSX). The 18 specimens (3 of each composite) were prepared in split Teflon moulds of 4 mm diameter and 6 mm thickness. All composites were cured in standard mode for 20 s using LED LCU (D-Light Duo, RF-Pharmaceuticals Sarl, Geneva, Switzerland; 1200–1300 mW/cm). The VMH was measured using a digital Micro Hardness Tester Shimadzu (HMV-2T E, Shimadzu Corporation, Kyoto, Japan). A 50 g (0.5 N) load force was applied for 30 s. Each specimen was measured at five places selected by chance at each level (N = 15). The hardness ratio or DOC was calculated for all samples as the ratio of bottom and surface microhardness at levels of 4 and 6 mm. Data were analysed using one-way ANOVA and Tukey’s post hoc test. Results. Significant reduction in VMH was observed for all tested materials when comparing top surface and bottom (p &lt; 0.01). The highest VMH was obtained for GSX and AFX, and the lowest for TEC. The results show that the degree of polymerization was adequate for all tested materials at a depth of 6 mm, since the hardness ratio exceeded 0.80 in all cases. The hardness ratio at 4 mm was high for all tested composites ranging from 0.91 for TEC to 0.98 for GSX. All composites showed adequate DOC at the bottom of the 6 mm bulk samples. However, the hardness ratio was the highest for Admira Fusion X-tra (0.96) and GrandioSO X-tra (0.97). Conclusions. All tested materials showed a significant decrease in microhardness from the top surface to the bottom. The DOC was adequate for all bulk-fill composites at a depth of 6 mm cured under standard mode for 20 s. All bulk-fill resin composites evaluated in this study can be used in bulk, up to 6 mm.

Shrinkage stress is determined by the elastic modulus during shrinkage, not the final elastic modulus.

BackgroundTo evaluate the impact of different polishing systems on surface roughness (SR), surface gloss (SG), and vickers microhardness (VMH) of flowable bulk-fill composites reinforced with zirconium oxide fillers.MethodsTwo flowable bulk-fill composites reinforced with zirconium oxide fillers (PALFIQUE BULK FLOW, Filtek Bulk Fill Flowable) and another one with conventional fillers (Tetric N-Flow Bulk Fill) were used. For each tested material, 40 cylindrical specimens (8-mm diameter, 4-mm height) were prepared. Specimens were divided into 4 subgroups according to polishing system used (n = 10/subgroup): subgroup I; Mylar strip (control), subgroup II; 1-step polishing system, subgroup III; 2-step polishing system, and subgroup IV; multi-step polishing system. Surface roughness was evaluated with a 3D noncontact optical profilometer. Gloss was evaluated with a glossmeter. Microhardness was evaluated with a Vickers Microhardness tester. Statistical analysis was performed using two-way ANOVA, Bonferroni, and Pearson correlation coefficient testes (p < 0.05).ResultsFor surface roughness, there was no significant difference between groups for control and 1-step (p = 0.152 for control, p = 0.296 for 1-step), while there was a significant difference for 2-step and multi-step (p = 0.025 for 2-step, p = 0.001 for multi-step). For gloss, there was no significant difference between groups for 1-step and 2-step (p = 0.124 for 1-step, p = 0.226 for 2-step), while there was a significant difference for control and multi-step (p = 0.001 for control, p < 0.001 for multi-step). For microhardness, there was no significant difference between groups for control (p = 0.245), while there was a significant difference for the other techniques (p < 0.001 for 1-step and 2-step, p = 0.001 for multi-step).ConclusionsReinforcement with zirconium oxide fillers improved flowable bulk-fill composites in terms of surface roughness, gloss, and microhardness. Surface gloss and microhardness were significantly influenced by material type and polishing system used, while surface roughness was influenced only by polishing system used.

Introduction: Currently, the market offers Bulk Fill resins that are used with the monobloc or single-increment technique (up to 4 or 5 mm). These resins are characterized by a lower filler content and larger filler particles, improved translucency, and a different chemical structure of the monomers in the filler compounds, which—when placed in a single block—reduce polymerization stress. Objective: To evaluate the level of marginal microleakage of two Bulk Fill resins using the deproteinization technique prior to acid etching. Methods: This is an in vitro study in which 64 extracted premolars underwent standardized cavity preparations. The teeth were randomly divided into four groups and subjected to a manual thermocycling process of 500 cycles. All samples were immersed in a 2% methylene blue solution for 24 hours. Microleakage was then observed with a stereomicroscope. Results: For the Aura Bulk Fill resin, microleakage in enamel was observed in 25% of the deproteinized samples and in 18.8% of the non-deproteinized samples. For the Filtek Bulk Fill resin, 31.3% of the samples exhibited microleakage in enamel with the deproteinization technique and 25.0% without deproteinization. No statistically significant differences were found. Conclusions: All samples presented microleakage, with similar levels in both brands of Bulk Fill resins, and no significant differences were observed with the application of the deproteinization technique.

Background: Composite resins are widely used for esthetic dental restorations, but polymerization shrinkage can cause cuspal deflection and microleakage, compromising restoration longevity. Aim: The study aimed to evaluate cuspal displacement and marginal leakage in Class II restorations employing bulk-fill composite resin (Filtek Bulk Fill) and nanocomposite (Filtek Z350 XT). Materials and Methods: Thirty-two intact maxillary first premolars obtained immediately postextraction were embedded 3 mm below the cementoenamel junction in acrylic resin. Two composite-filled plastic molds were fixed on the palatal and buccal cusps as points of reference, and buccopalatal widths (BPWs) were measured using a digital micrometer. Standardized Class II mesio–occluso–distal (MOD) cavities (2 mm width and 2 mm depth) were prepared and restored with either nanocomposite (Group A) or bulk-fill composite (Group B). After restoration, BPWs were remeasured to assess cuspal deflection. Samples underwent 500 thermal cycles (5°C–55°C), were stained with 2% methylene blue, and sectioned for microleakage analysis under a stereomicroscope at ×20. Differences between the groups were analyzed, with a significance level of 5%. Results: Group A exhibited a greater average cuspal deflection (0.144 ± 0.26 mm) compared to Group B (0.07 ± 0.16 mm), even though this discrepancy was not notably significant (P = 0.3). After thermocycling, Group A also had greater cuspal deflection (P = 0.61) and higher median microleakage (1.5 [1–2.75]) compared to Group B (P = 0.46). Conclusion: Nanocomposite showed higher cuspal deflection and microleakage than bulk-fill composite in large MOD cavities, although these differences were not statistically significant.

ABSTRACTAim:To compare marginal adaptation of bulkfill low shrinkage composite in a class II cavity under scanning electron microscope.Materials and Methods:52 extracted human molars were stored in the saline. Class II cavities were prepared extending 1mm below CEJ. The teeth were randomly assigned to 4 groups (n = 13). GROUP 1- Tetric N Ceram, GROUP 2- SDR, GROUP 3- Sonicfill, GROUP 4- Filtek bulkfill. All the cavities were then restored with the composite according to each manufacturer’s instructions and they were polished using flexible polishing discs. The teeth were sectioned labiolingually, mesial halves of the tooth samples were observed under SEM for marginal adaptation, and distal halves were thermocycled and observed under SEM.Results:Marginal adaptation seen in both SDR and sonicfill was better when compared to Tetric N Ceram and Filtek bulk fill and also all four experimental groups showed better enamel adaptation when compared to the adaptation in the cementum.

Purpose: This in-vitro study aimed to evaluate the shear bond strength of different resin composites to Biodentine. Materials &amp; Methods: Sixty acrylic blocks with a central hole (2mmx5mm) were fabricated(n=60). The holes were filled with Biodentine(Septodont), and the samples were randomly divided into three groups based on the type of restorative material: 1)Conventional posterior composite, Estelite Posterior Quick (EP)(Tokuyama); 2) Bulk-fill composite, Filtek Bulk Fill (FB)(3M ESPE); and 3) Short fiber-reinforced composite, EverX Posterior (EX)(GC). Additionally, each group was subdivided into two categories depending on the adhesive application method: self-etch and total-etch. A universal adhesive(Single Bond Universal,3M ESPE) was applied to the Biodentine specimens. Subsequently, the resin composites were applied and light-cured for 20 seconds. The shear bond strength was measured using a universal testing machine (AGS-1000D, Shimadzu) at a crosshead speed of 1 mm/min. The shear bond strength data (MPa) were analyzed using two-way ANOVA and the Bonferroni test(p

This study evaluated the one-year clinical performance of Cention N, a new alkasite bioactive restorative material, compared to a conventional bulk-fill composite resin in 12 patients aged 18-45years with class I cavities. The patients were randomly assigned to three groups: Group I (Cention N without adhesive), Group II (Cention N with adhesive), and Group III (Filtek Bulk Fill composite resin). The restorations were monitored at baseline, three, six, and twelve months using the FDI criteria, assessing marginal staining, recurrent caries, and postoperative sensitivity. Statistical analysis was performed using the Monte Carlo correction, chi-square test, and Friedman's test (p ≤ 0.05). The results showed clinically acceptable FDI scores for all restorations at each time interval with no significant differences between the groups (p ≥ 0.05). However, Cention N without adhesive demonstrated slightly inferior outcomes in postoperative sensitivity and marginal staining at the six- and twelve-month intervals. Overall, both materials performed similarly in terms of clinical performance within the first year, though Cention N without adhesive showed marginally lower, but still acceptable, results.Trial registration: ClinicalTrials.gov NCT06273410: 13/10/2022.

ABSTRACTObjectivesThis study aimed to quantify polymerization shrinkage, microhardness, and depth of cure of different types of bulk‐fill composites.MethodsSix bulk‐fill composites were tested: SonicFill 2 (SCF), VisCalor (VVC), Admira Fusion x‐tra (AFX), Filtek Bulk Fill (FBF), Fill‐Up! (FUP) and GrandioSO Heavy Flow (GHF). Sixty teeth were divided into twelve groups (n = 5) according to the composite and the irradiation level applied (standard or high). Each tooth was subjected to three scans using a micro‐computed tomography device. The microhardness of the composite specimens was measured using a Vickers hardness tester. Depth of cure analysis was performed by measuring the microhardness of the composites at 0.5 mm intervals from the top surface to the bottom surface.ResultsThe highest volumetric shrinkage was found in the AFX group when polymerized at standard irradiance. After curing, the AFX group showed the highest void ratio. Increasing irradiance significantly increased volumetric shrinkage and void ratio only in the SCF group (p < 0.05). GHF achieved the maximum microhardness value of 80% at the lowest curing depth of 2.9 mm, while VVC, AFX, and SCF showed a curing depth of more than 5 mm (p < 0.05).ConclusionsThe high irradiance caused the most significant volumetric shrinkage and void ratio in the SCF group. Only the FUP and GHF groups were unable to achieve the desired curing depth of 4 mm.Clinical RelevanceIrradiance, material types, and thickness are important factors in the polymerization of composites.

BackgroundThis study aimed to evaluate the effects of different restorative techniques and materials on cuspal deflection and microleakage in MOD restorations. Eight groups were tested using incremental and bulk-fill techniques, with or without fiber reinforcement. The restorative materials included Filtek Z250 and Filtek Bulk-fill Posterior, while reinforcement materials such as Interlig glass fiber, EverX Posterior, and Surefill SDR were incorporated to assess their impact.MethodsIn total, 96 freshly extracted, sound human maxillary first premolars were selected and stored in 0.1% thymol solution at 37 °C. The teeth were randomly assigned into eight groups (n = 12). Standardized MOD cavities were prepared, followed by endodontic treatment and sealing with glass ionomer cement. The groups were as follows: Group 1—Filtek Z250 applied incrementally in 2-mm layers; Group 2—U-shaped Interlig glass fiber followed by incremental Filtek Z250; Group 3—Filtek Bulk-fill Posterior using the bulk technique; Group 4—U-shaped Interlig glass fiber followed by Filtek Bulk-fill Posterior; Group 5—EverX Posterior followed by incremental Filtek Z250; Group 6—EverX Posterior followed by Filtek Bulk-fill Posterior; Group 7—Surefill SDR followed by incremental Filtek Z250; and Group 8—Surefill SDR followed by Filtek Bulk-fill Posterior. Cuspal deflection was measured using a digital micrometer with 0.05 μm precision. Microleakage was assessed using a 0.5% basic fuchsin dye solution at 37 °C for 24 h, followed by sectioning and examination under magnification.ResultsThe lowest mean cuspal deflection was observed in Group 2 (15.8 μm), while the highest was in Group 5 (27.2 μm). Statistically significant differences were observed in cuspal deflection across the groups and over time (p < 0.05). Significant differences in microleakage scores were also found among the groups, indicating the impact of restorative materials and techniques on these outcomes (p < 0.05).ConclusionThis study demonstrated that Filtek Z250 and Filtek Bulk-fill Posterior showed different effects on cuspal deflection and microleakage. The use of glass fiber and EverX Posterior improved restoration performance by reducing polymerization effects. Surefill SDR also reduced cuspal deflection due to its low polymerization shrinkage. Clinically, selecting the appropriate restorative materials and techniques based on the extent of tooth structure loss can improve long-term outcomes.

Purpose The purpose of this in vitro study was to examine the impact of surface pre-treatment on the shear bond strength (SBS) of an adhesive resin cement to super-translucent multi-layered (STML) zirconia. Materials and methods Forty (n = 40) uniformly sized discs of STML zirconia (Katana, Kuraray, Noritake Dental Inc., Okayama, Japan), with dimensions of 3 mm in diameter and 3 mm in thickness, were produced using computer-aided design (CAD)/computer-aided manufacturing (CAM) technology and subsequently sintered following the manufacturer's instructions. The discs were subsequently divided into four equal groups (n = 10 each) based on the surface treatment method applied as follows: group 1 - control group with no treatment (Co); group 2 - sandblasting (SB); group 3 - Zircos Acids Zircos-E etching solution (BIO DEN CO, Seoul, Korea) (Z); group 4 - erbium-doped yttrium aluminum garnet (Er:YAG) laser. Surface roughness (Ra) was evaluated for each group. Round composite discs (Filtek Bulk Fill, 3M ESPE, St. Paul, MN), measuring 3 × 2 mm, were prepared for SBS testing and then bonded to the ceramic sample surface using composite resin cement (RelyX Ultimate Automix, 3M ESPE, Neuss, Germany). After securing the composite disc on the sample, each sample underwent an SBS test at a stress rate of 1 MPa/second with a force of 10 N. To ascertain the fracture type, fractured samples were inspected under a microscope. The ANOVA and post-hoc Tukey tests were employed to analyze differences in bond strength values among groups. All tests were conducted with a significance level of α = 0.05. Results Significant differences were observed in the SBS of cement applied to zirconium dioxide dental ceramics following various preparation methods. Statistically significant differences in the mean shear stress values (in megapascals) were found between the Z group and the Co group, as well as between the Er:YAG group and the other groups. Conclusions The application of Zircos-E for etching super ultra-translucent zirconia presents a promising approach to enhancing resin bonding, particularly in comparison to techniques involving Er:YAG laser and sandblasting.

The study aimed to compare the surface changes of Filtek Z350XT, Filtek Bulk Fill, and Opus Bulk Fill resins immersed in Maltin Power® and Volt® energy drinks using surface microhardness testing. This experimental study evaluated two types of bulk fill resins and Filtek resin (control). Forty-eight resin discs measuring 4x4 mm were prepared and soaked in 20 ml of an energy drink for 10 minutes daily for 7 and 30 days. Surface microhardness was assessed using the Vickers microhardness method. Repeated samples were analyzed using the ANOVA test, and multiple comparisons were conducted using the Bonferroni test. Finally, the Kruskal-Wallis test also was applied (P< 0.05). The decrease in surface microhardness of the three resins exposed to the two energy drinks was significant (P<0.05). After immersion in the Volt energy drink over 30 days, the Filtek Z350XT, Filtek Bulk Fill, and Opus Bulk Fill resins showed decreases in surface microhardness of 3.89±1.94; 7.74±4.66 and 5.86±3.17, respectively, while the respective decreases after immersion in the Maltin Power energy drink were 3.67±4.08, 5.70±0.99, and 3.23±1.76. Immersion in the energy drinks changed the surface microhardness of bulk fill resins after 7 and 30 days. Both clinicians and patients should consider these findings when determining the consumption frequency of these beverages. Key words:Energy drink, hardness test, composite resins.

The emergence of toothpastes containing different abrasive and whitening substances has been a constant concern among dental professionals. The aim of the present study was to perform an in vitro assessment of the surface topography of nanoparticle composite resins subjected to simulated brushing with dentifrices. Test samples were prepared with Filtek Universal (3M ESPE), Filtek Bulkfill (3M ESPE) and Z350 (3M ESPE), with 24 samples per resin. A testing machine was used to simulate brushing with the dentifrices Colgate Total 12, Oral B 100% and Oral B Gengiva Detox Gentle Whitening (8 samples per group). The constant speed of the machine was 250 cycles per minute, and 20.000 cycles were carried out, which corresponds to 24 months (1 hour and 20 minutes). Roughness features and qualitative surface topography were investigated. Statistical analysis involved the Kruskal-Wallis, Wilcoxon and Mann-Whitney tests. A significant increase in surface roughness was found for all the resins (p < 0.05). However, no significant difference was found among the resins in terms of final roughness values (p = 0.690). In contrast, a significant difference among dentifrices was found with respect to roughness measurements (p < 0.001). The qualitative analysis revealed an increase in surface roughness in all the samples and differences in the abrasive potential of the dentifrices. In conclusion, brushing with dentifrices increases the surface roughness parameters of composite resin restorations. Moreover, the differences in the abrasive effects of the dentifrices indicate a need for further studies to establish efficacy and safety criteria.

This study investigated the effect of indirect air-cooling on the variation in intrapulpal temperature (ΔT) during different light-curing protocols of bulk-fill resin composites in molars with class V cavities. A nonretentive class V cavity was prepared in a maxillary molar. The intrapulpal temperature changes with and without indirect air-cooling were recorded using a type K thermocouple. The cavity was restored with bulk-fill resin composites: Tetric PowerFlow (Ivoclar, Vivadent) and Filtek Bulk-Fill Flow (3 M, ESPE). The tooth was exposed to different light-curing protocols (n=5) using the Valo Grand light-curing unit: (i) high-intensity light-curing protocol of 3200 mW/cm² (3 and 6 s) and (ii) moderate-intensity light-curing protocol of 1000 mW/cm² (10 and 20 s). The ΔT data were subjected to two-way ANOVA, followed by the Bonferroni post hoc test. A significant increase in temperature was observed with the use of the high-intensity light-curing resin composite without indirect air-cooling. In addition, the application of air-cooling significantly decreased the temperature in all the groups except for the Tetric PowerFlow bulk-fill resin composite at 3 s of light-curing. Indirect air-cooling resulted in a lower increase in intrapulpal temperature during the light-curing of bulk-fill resin composites, making it an effective alternative technique for controlling the temperature rise in class V restorations with 1 mm of remaining dentin. Key words:Dental curing lights, dental pulp, temperature, resin composite.

This study aimed to evaluate the depth of cure (DoC) of bulk-fill composite resins, measured by the bottom-to-top Vickers microhardness ratio, using different light-curing units (LCUs): single-wave LED, polywave LED, and halogen. Six bulk-fill composites—Tetric EvoCeram Bulk Fill, X-tra base, SonicFill, Venus Bulk Fill, SDR, and Filtek Bulk Fill—were tested. Four LCUs, including one halogen (Elipar Trilight) and three LEDs (Demi Ultra, Valo, and Bluephase style), were employed for polymerization. Vickers hardness measurements were taken at depths of 1 mm to 5 mm. One- and two-way ANOVA (α = 0.05) were used for data analysis. The results revealed significant differences in microhardness and microhardness ratios among the composites at depths of 4 mm and beyond, depending on the LCU used. It was observed that most bulk-fill composites showed an adequate DoC up to 4 mm, but the effectiveness varied with different LCUs. Importantly, polywave LED LCUs did not exhibit a superior advantage in achieving depth of cure compared to monowave LED LCUs for composites containing multiple photoinitiators. These findings suggest that while several factors affect the DoC, the type of LCU plays a crucial role, and polywave LEDs may not offer additional benefits over monowave LEDs.