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The current development of dental materials aims to improve their properties and expand their clinical application. New flowable bulk-fill composites have been released which, unlike what was previously common in this material category, are intended to be used alone and without a top layer, in various cavities. The study compares their kinetic of light transmission during monomer-to-polymer conversion on a laboratory-grade spectrometer, as well as their elastoplastic and aging behavior under simulated clinical conditions. Major differences in the kinetic of light transmission was observed, which is related to the degree of mismatch between the refractive indices of filler and polymer matrix during polymerization and/or the type of initiator used. Compared to the literature data, the kinetic of light transmission do not always correlate with the kinetic of functional group conversion, and therefore should not be used to assess polymerization quality or to determine an appropriate exposure time. Furthermore, the initial mechanical properties are directly related to the volumetric amount of filler, but degradation during aging must be considered as a multifactorial event. [ABSTRACT FROM AUTHOR]

Objectives: This study evaluated the clinical performance of bulk‐fill resin composite systems with different viscosities in class II cavities. Materials and Methods: 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. Results: 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. Conclusions: 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. [ABSTRACT FROM AUTHOR]

This article proposes a technique to simplify the cementation of indirect restorations by exploiting the advantageous properties of bulk-fill composites (BFCs). The proposed technique consists of using a thin layer of a high-viscosity (HV) BFC in the interproximal margins of the preparation and applying low-viscosity (LV) resin luting agents (RLAs) to the rest of the prepared surface. The application of the HV BFC limits the extrusion of the LV RLAs in the interproximal area, deviating the excesses of LV RLAs only on the vestibular and lingual side. This deviation allows the management and control of the excess material in complicated interproximal spaces, simplifying the cementation procedure of indirect restorations and achieving a reliable final result in terms of removing excess in a safe and repeatable way. This technical report provides an alternative clinical approach for cementing indirect restorations using the consistency and viscosity of different RLAs. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to investigate the effect of different light curing modes on the polymerization shrinkage of a bulk-fill composite and to evaluate the impact of two layering techniques on the cuspal deflection. Methods: Nine different light curing modes were tested on bulk-fill composite samples in aluminum MOD cavities. Intensity, duration, and illumination distance were the factors that changed during the different curing modes. The digital image correlation method was used to visually represent the displacement of carbon particles on the materials' surface caused by shrinkage along both the horizontal and vertical axes. For simulating cuspal deflection, a separate protocol was used, with a bulk and horizontal layering technique. Results: The results showed that the largest horizontal displacements were present in the soft start group (6.00 ± 0.82 µm) and in the X-tra power group (5.67 ± 1.21 µm). The smallest horizontal displacements were detected in normal curing modes (4.00 ± 1.58 µm; 4.00 ± 2.68 µm). The largest vertical displacements, at the bottom layer, were present in the normal curing mode group with a 20 s curing time (5.22 ± 1.56 µm), while the smallest vertical displacements were shown in the X-tra power group (2.89 ± 0.60 µm). The observed particle displacements showing the shrinkage of the composite were correlated with the curing mode. The bulk-fill group showed less cuspal deflection than the horizontal layering group did, but the difference was not statistically significant (p = 0.575). Conclusions: Within the limitations of this in vitro study, it can be concluded that lower intensities of curing lights (1200 mW/cm2) may perform better from the point of view of material shrinkage than high and extreme light intensities do. The pulse delay mode might be recommended in the case of bulk-fill materials. The number of layers did not significantly affect the cuspal deflection in the case of the studied composite. [ABSTRACT FROM AUTHOR]

Background: This study aims to evaluate the effect of preheating on microhardness, degree of conversion, and depth of cure of bulk-fill composites (Tetric EvoCeram Bulk-Fill, SonicFill2) and a conventional composite (Tetric EvoCeram). Methods: Layers of Tetric EvoCeram (2 mm), Tetric EvoCeram Bulk-Fill (4 mm), and SonicFill2 (5 mm) were placed in 4-mm diameter molds and polymerized at room temperature or heated to 55oC for 10 s with a total number of 60 samples. Then, the top surfaces of samples were polished. 30 samples’ Vickers microhardness was measured from the top and bottom surfaces. The other 30 samples were pulverized into a fine powder, and the composites’ degree of conversion was measured with attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. Obtained data were analyzed statistically with a significance level of p

Abstract Objectives The trial aimed to compare the clinical performance and radiographic success of ACTIVA BioACTIVE versus Compomer in restoring class-II cavities of primary molars. Materials and methods A non-inferior split-mouth design was considered. A pre-calculated sample size of 96 molars (48 per group) with class-2 cavities of twenty-one children whose ages ranged from 5 to 10 years were randomly included in the trial. Pre-operative Plaque Index (PI), DMFT/dmft scores and the time required to fill the cavity were recorded. Over 24 months, the teeth were clinically evaluated every six months and radiographically every 12 months by two calibrated and blinded evaluators using the United States public health service (USPHS)-Ryge criteria. The two-sided 95% confidence interval (CI) for the difference in success rate was considered to assess non-inferiority, and the margin was set at -18%. The linear mixed model and Firth’s logistic regression model were used for data analysis (P 0.05). ACTIVA took significantly less placement time than Dyract, with a mean difference of 2.37 (± 0.63) minutes (P

Objectives: The trial aimed to compare the clinical performance and radiographic success of ACTIVA BioACTIVE versus Compomer in restoring class-II cavities of primary molars. Materials and methods: A non-inferior split-mouth design was considered. A pre-calculated sample size of 96 molars (48 per group) with class-2 cavities of twenty-one children whose ages ranged from 5 to 10 years were randomly included in the trial. Pre-operative Plaque Index (PI), DMFT/dmft scores and the time required to fill the cavity were recorded. Over 24 months, the teeth were clinically evaluated every six months and radiographically every 12 months by two calibrated and blinded evaluators using the United States public health service (USPHS)-Ryge criteria. The two-sided 95% confidence interval (CI) for the difference in success rate was considered to assess non-inferiority, and the margin was set at -18%. The linear mixed model and Firth's logistic regression model were used for data analysis (P < 0.05). Results: After 24 months, 86 teeth (43 per group) were evaluated. The mean PI score was 1.1(± 0.9), while DMFT/dmft was 0.35 (± 0.74) and 6.55 (± 2.25) respectively. The clinical and radiographic success rate of Dyract vs. ACTIVA was 95.3% and 88.3% vs. 93% and 86%, respectively. The two-sided 95% CI for the difference in success rate (-2.3%) was − 3.2 to 1.3% and didn't reach the predetermined margin of -18% which had been anticipated as the non-inferiority margin. Clinically, ACTIVA had a significantly better colour match (P = 0.002) but worse marginal discolouration (P = 0.0143). There were no significant differences regarding other clinical or radiographic criteria (P > 0.05). ACTIVA took significantly less placement time than Dyract, with a mean difference of 2.37 (± 0.63) minutes (P < 0.001). Conclusion: The performance of ACTIVA was not inferior to Dyract and both materials had a comparable high clinical and radiographic performance in children with high-caries experience. ACTIVA had a significantly better colour match but more marginal discolouration. It took significantly less time to be placed in the oral cavity. Trial registration: The study was registered at ClinicalTrials.gov on 4 May 2018 (#NCT03516838). [ABSTRACT FROM AUTHOR]

Context: The restorative complexities associated with endodontically treated teeth surpass those encountered with vital ones. The field of adhesive dentistry experienced a significant advancement that led to a shift in treatment approach toward bonded restorations. Aim: The aim of the study was to assess the clinical performance of using indirect Milled composite or direct bulk-fill resin composite restorations for endo-treated teeth, as well as to measure the amount of wear on the occlusal tables of both restorations using a digital scanner. Subjects and Methods: Participants were divided into two groups, where R1 represents the endodontically treated teeth restored with Milled composite, R2 represents the endodontically treated teeth restored with direct bulk-fill composite where 13 patients in each group were treated with a total number of 26 restorations in all patients. Where each restoration was assessed immediately at baseline (T0), 6 months (T6), and 12 months (T12) using the modified United States Public Health Service criteria. Moreover, wear was measured immediately at (T0) and (T12) intraorally and extraorally using intraoral scanners and three-dimensional surface-based superimposition software. Statistical Analysis Used: Chi-squared test, Mann-Whitney U-test, Friedman's test, Nemenyi post hoc test, Shapiro-Wilk test, paired t-tests, intraclass correlation coefficient. Results: At all intervals, the majority of the cases in both groups had an alpha score. Some cases exhibited bravo scores in both groups at T6 and T12 regarding the color match, marginal adaptation, marginal discoloration, and marginal integrity without statistically significant difference (P > 0.05). Direct nanohybrid bulk-fill resin composite showed a greater amount of wear without a statistically significant difference (P > 0.05). Extraoral measurement was significantly higher than intraoral measurement (P < 0.001). There was no significant reliability/agreement between both methods. Conclusions: Both milled composite and direct bulk-fill resin composite restorations in endodontically treated teeth demonstrated appropriate clinical performance and minimal wear over an 1-year follow-up period. [ABSTRACT FROM AUTHOR]

To evaluate the initial bacterial adherence and biofilm formation on novel restorative materials in paediatric dentistry and compare the results to stainless steel crown and primary enamel. Twenty-five samples (Diameter = 4 mm) from five restorative materials (Tetric Power Fill light cured for 3 s or 10 s, Fuji II LC, Equia Forte HT Fil, Cention Forte, Stainless-steel crown) and primary enamel were prepared. Four samples served for recording of surface roughness (R a) using a contact profilometer, 21 samples were incubated in stimulated human saliva for 2 h (initial bacterial adherence) and 72 h (biofilm formation) and served to determine ion releasing and bacterial growth. After 2 and 72 h, the number of colony-forming units (CFU) per ml was counted and expressed in Log 10 CFU/ml. Data were analysed with two-way ANOVA and Tuckey's multiple comparisons test (p < 0.05). All tested materials showed similar initial bacterial adherence (p > 0.1). Stainless steel crown showed statistically significantly less biofilm formation than all other tested materials (p ≤ 0.02), except for Fuji II LC (p = 0.06). In terms of biofilm formation, the differences between all tested materials were not statistically significant (p ≥ 0.9). Novel restorative materials in paediatric dentistry show similar initial bacterial adherence and biofilm formation. However, compared to other restorative materials, stainless steel crowns demonstrate the lowest level of biofilm formation. Ion-releasing materials may not necessarily show better antimicrobial properties than conventional materials. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the clinical performance of surface sealants associated with a bulk-fill composite in posterior restorations after 4 years. A total of 174 posterior restorations were performed on 57 participants using a self-etch adhesive system and a bulk-fill composite. The groups were then divided into the following categories: 1) without surface sealant (NoS), 2) with surface sealant Biscover (Bisco, SBi), and 3) with surface sealant Permaseal (Ultradent, SPe). Restorations were evaluated using FDI criteria at baseline and after 1 and 4 years. Statistical analysis was conducted using Kaplan-Meier survival analysis and the Chi-square test (α = 0.05). After 4 years, only one restoration was lost (1 in the NoS group). The fracture/retention rate (with 95% confidence interval) was 98% for NoS and 100% for both SBi and SPe (p = 0.76). The majority of secondary outcomes showed minor defects, with no significant differences among the groups (p > 0.05). However, significant differences were observed among the groups in terms of marginal staining and marginal adaptation (p = 0.03). In both items, twelve restorations (nine in NoS, one in SBi, and two in SPe) showed minor marginal discrepancies favoring the sealant groups (SBi and SPe). Regardless of the use of surface sealants, the bulk-fill composite restorations showed excellent clinical performance after 4 years. However, the groups that received sealants showed better marginal adaptation and less marginal discoloration compared to those that did not receive sealants. • Surface sealants may not significantly influence the longevity of 4-year composite restorations. • Restorations with surface sealants showed a subtle reduction in marginal defects. • Participants' age could be a factor influencing the risk of post-operative sensitivity. • Deeper cavities may increase the risk of post-operative sensitivity. [ABSTRACT FROM AUTHOR]

In the chronology of polymer-based composite materials, flowable bulk-fill composites represent the most recent development. They enable a significant reduction in treatment time by being applied in larger increments of 4 to 5 mm. The aim of the investigation was to assess the polymerization quality and mechanical performance of a new formulation that has just entered the market and was still in experimental formulation at the time of the investigation, and to compare these results in the context of clinically established materials of the same category. Adequate curing in increments of up to 4 mm could be confirmed both by profiling the elastoplastic material behavior of large increments in 100 µm steps and by real-time assessment of the degree of conversion and the associated polymerization kinetic. A slightly lower amount of filler in the experimental material was associated with slightly lower hardness and elastic modulus parameters, but the creep was similar and the elastic and total indentation work was higher. The kinetic parameters were assigned to the specific characteristics of each tested material. The mechanical macroscopic strength, evaluated in a three-point bending test and supplemented by a reliability analysis, met or exceeded the standards and values measured in clinically established materials, which for all materials is related to the higher flexibility of the beams during testing, while the modulus of elasticity was low. The low elastic modulus of all flowable bulk-fill materials must be taken into account when deciding the clinical indication of this material category. [ABSTRACT FROM AUTHOR]

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The current development of dental materials aims to improve their properties and expand their clinical application. New flowable bulk-fill composites have been released which, unlike what was previously common in this material category, are intended to be used alone and without a top layer, in various cavities. The study compares their kinetic of light transmission during monomer-to-polymer conversion on a laboratory-grade spectrometer, as well as their elastoplastic and aging behavior under simulated clinical conditions. Major differences in the kinetic of light transmission was observed, which is related to the degree of mismatch between the refractive indices of filler and polymer matrix during polymerization and/or the type of initiator used. Compared to the literature data, the kinetic of light transmission do not always correlate with the kinetic of functional group conversion, and therefore should not be used to assess polymerization quality or to determine an appropriate exposure time. Furthermore, the initial mechanical properties are directly related to the volumetric amount of filler, but degradation during aging must be considered as a multifactorial event.

This article proposes a technique to simplify the cementation of indirect restorations by exploiting the advantageous properties of bulk-fill composites (BFCs). The proposed technique consists of using a thin layer of a high-viscosity (HV) BFC in the interproximal margins of the preparation and applying low-viscosity (LV) resin luting agents (RLAs) to the rest of the prepared surface. The application of the HV BFC limits the extrusion of the LV RLAs in the interproximal area, deviating the excesses of LV RLAs only on the vestibular and lingual side. This deviation allows the management and control of the excess material in complicated interproximal spaces, simplifying the cementation procedure of indirect restorations and achieving a reliable final result in terms of removing excess in a safe and repeatable way. This technical report provides an alternative clinical approach for cementing indirect restorations using the consistency and viscosity of different RLAs.

Background: The purpose of this study was to investigate the effect of different light curing modes on the polymerization shrinkage of a bulk-fill composite and to evaluate the impact of two layering techniques on the cuspal deflection. Methods: Nine different light curing modes were tested on bulk-fill composite samples in aluminum MOD cavities. Intensity, duration, and illumination distance were the factors that changed during the different curing modes. The digital image correlation method was used to visually represent the displacement of carbon particles on the materials’ surface caused by shrinkage along both the horizontal and vertical axes. For simulating cuspal deflection, a separate protocol was used, with a bulk and horizontal layering technique. Results: The results showed that the largest horizontal displacements were present in the soft start group (6.00 ± 0.82 µm) and in the X-tra power group (5.67 ± 1.21 µm). The smallest horizontal displacements were detected in normal curing modes (4.00 ± 1.58 µm; 4.00 ± 2.68 µm). The largest vertical displacements, at the bottom layer, were present in the normal curing mode group with a 20 s curing time (5.22 ± 1.56 µm), while the smallest vertical displacements were shown in the X-tra power group (2.89 ± 0.60 µm). The observed particle displacements showing the shrinkage of the composite were correlated with the curing mode. The bulk-fill group showed less cuspal deflection than the horizontal layering group did, but the difference was not statistically significant (p = 0.575). Conclusions: Within the limitations of this in vitro study, it can be concluded that lower intensities of curing lights (1200 mW/cm2) may perform better from the point of view of material shrinkage than high and extreme light intensities do. The pulse delay mode might be recommended in the case of bulk-fill materials. The number of layers did not significantly affect the cuspal deflection in the case of the studied composite.

Abstract Background Reducing the necessary time to restore primary teeth improves the cooperation of paediatric patients. This study aimed to investigate the marginal integrity of restorations prepared with a bulk-fill resin-based composite (RBC) containing additional fragmentation chain transfer (AFCT) compared to a conventional RBC when light cured with a rapid high-irradiance (3 s) and a regular (10 s) curing mode. Methods Forty class-II cavities were prepared in 40 primary molars. The molars were randomly divided into four groups based on the applied light-curing modes (regular: 10 s @ 1200 mW/cm2 or high-irradiance: 3 s @ 3000 mW/cm2) and the used restorative material (AFCT-containing bulk-fill RBC “Power Fill” or AFCT-free conventional RBC “Prime”). After thermo-mechanical loading, the marginal integrity was analysed using scanning electron microscopy. A beta regression model and pairwise comparisons were used to statistically analyse the data. Results The mean marginal integrity (% ± SD) of the restorations for each group was as follows: Power Fill (10 s: 79.7 ± 15.6) (3 s: 77.6 ± 11.3), Prime (10 s: 69.7 ± 11.1) (3 s: 75.0 ± 9.7). The difference between the RBCs for the same light-curing mode was statistically significant (p ≤ 0.05). The difference between the light-curing modes for the same RBC was not statistically significant (p ˃ 0.5). Conclusions AFCT-containing bulk-fill RBC “Power Fill” achieves similar marginal integrity when light-cured with either high-irradiance or regular light-curing modes. “Power Fill” achieves better marginal integrity than the conventional RBC “Prime” regardless of the applied light-curing mode.

Introduction: The aim of this study was to investigate the effect of thermal cycling on the surface geometry of high-viscosity bulk-fill resin-based composites (RBCs) compared to conventional nanohybrid composites. Materials and methods: Four conventional nanohybrid composites (Tetric EvoCeram – TEC, GrandioSO – GD, Filtek Z550 – FZ, and Ceram·X Mono – CX) and 4 high-viscosity bulk-fill composites (Tetric EvoCeram Bulk Fill – TBF, X-tra fil – XF, Filtek Bulk Fill Posterior – FBF, and QuixFil – QF) were tested. After the 2-step polishing procedure, the samples were divided into 2 groups: control group (K) and thermal cycling group (TC). Samples from the TC were subjected to thermal cycling according to ISO 11405 (THE-1100, SD Mechatronik GmbH). Surface geometry was evaluated by profilometry (Turbowave v. 7.36, Hommel-Etamic) and scanning electron microscope – SEM (VEGA 3, Tescan Analytics). Results: The applied thermal cycles increased the surface roughness of conventional RBCs: TEC (p = 0.000007), GD (p = 0.04), and CX (p = 0.0005). A reduction in the surface roughness of bulk-fill composites was observed in the case of materials: XF (p = 0.000003) and QF (p = 0.0002). Thermal cycling was shown to alter the surface roughness of the TEC, CX, XF, and QF materials. Conclusion: The application of thermal cycling in a water environment in accordance with the ISO 11405 standard causes the degradation of the organic matrix and the exposure of filler molecules on the surface of both conventional and high-viscosity bulk-fill composites. Some of the tested RBCs, especially those containing modern hydrophobic monomers, are less susceptible to these processes. [ABSTRACT FROM AUTHOR]

This study evaluated the interfacial integrity of deep (6 mm) Class-II (OM/OD) restorations placed using different bulk-fill resin composites [Filtek™ Bulk Fill Flowable Restorative (BF) and Filtek™ Bulk Fill Posterior Restorative (BP) (3M ESPE, St. Paul, MN, USA)] of different increment thicknesses (2 or 4 mm). BP was used for capping in all cases, while Filtek™ Z250 Universal Restorative (3M ESPE) was used as the control material. Interfacial debonding was measured during curing through acoustic emission (AE), followed by image analysis using micro-computed tomography and scanning electron microscopy. Microhardness testing was also conducted to assess degree of conversion. Depth of cure was adequate in all restorations. Specimens with 4-mm thick first increment of BF, which had a higher shrinkage strain, produced most AE events and debonding. Thus, bulk filling of deep cavities using bulk-fill resin composites with a high shrinkage strain should be avoided. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the fatigue performance and stress distribution of endodontically treated maxillary premolars with occlusal (O), mesio-occlusal (MO), or mesio-occluso-distal (MOD) cavities filled directly with bulk-fill composite. Materials and Methods: Besides the intact teeth (control group), sixty sound maxillary first premolars, standardized by size and morphology, were subjected to root canal treatment and randomly allocated to three groups throughout cavity preparations (O/MO/MOD). All cavities were restored with a bulk-fill composite (Tetric N-Ceram Bulk fill) and universal adhesive (Tetric N-Bond Universal) using etch-and-rinse mode. Half of the specimens of each group underwent 20,000 thermocycles (5°C-55°C). All specimens were subjected to a 50-N load perpendicular to their buccal bevels on the palatal cusps for 1,200,000 cycles. The survival curve and fracture mode were analyzed by log-rank and Fisher's exact tests, respectively. Finite element analysis (FEA) was conducted to simulate the working condition of premolars with O/MO/MOD cavities. The von Mises stress and the first principal stress were calculated for three FEA models. Results: Premolars with O cavity restorations exhibited better stress distributions than did those with MO and MOD cavity restorations. Compared to the intact premolars, no significant difference was detected in the fatigue performance of O/MO/MOD restorations, regardless of whether they underwent thermocycling. Only one specimen presented unrestorable fracture, while the rest of the fractured premolars were restorable. Conclusion: The cavity design of endodontic premolars restored with a bulk-fill composite has no influence on the stress distribution or fatigue survival, with a biomechanical performance similar to that of an intact tooth. [ABSTRACT FROM AUTHOR]

Background: Reducing the necessary time to restore primary teeth improves the cooperation of paediatric patients. This study aimed to investigate the marginal integrity of restorations prepared with a bulk-fill resin-based composite (RBC) containing additional fragmentation chain transfer (AFCT) compared to a conventional RBC when light cured with a rapid high-irradiance (3 s) and a regular (10 s) curing mode. Methods: Forty class-II cavities were prepared in 40 primary molars. The molars were randomly divided into four groups based on the applied light-curing modes (regular: 10 s @ 1200 mW/cm2 or high-irradiance: 3 s @ 3000 mW/cm2) and the used restorative material (AFCT-containing bulk-fill RBC "Power Fill" or AFCT-free conventional RBC "Prime"). After thermo-mechanical loading, the marginal integrity was analysed using scanning electron microscopy. A beta regression model and pairwise comparisons were used to statistically analyse the data. Results: The mean marginal integrity (% ± SD) of the restorations for each group was as follows: Power Fill (10 s: 79.7 ± 15.6) (3 s: 77.6 ± 11.3), Prime (10 s: 69.7 ± 11.1) (3 s: 75.0 ± 9.7). The difference between the RBCs for the same light-curing mode was statistically significant (p ≤ 0.05). The difference between the light-curing modes for the same RBC was not statistically significant (p ˃ 0.5). Conclusions: AFCT-containing bulk-fill RBC "Power Fill" achieves similar marginal integrity when light-cured with either high-irradiance or regular light-curing modes. "Power Fill" achieves better marginal integrity than the conventional RBC "Prime" regardless of the applied light-curing mode. [ABSTRACT FROM AUTHOR]

Bioactive materials have emerged as a promising alternative to conventional restorative materials as part of more conservative dentistry. The aim of this study was to evaluate and compare the shear bond strength (SBS) and microleakage of a new bioactive restorative material, two bulk-fill restorative composites, and a conventional composite at 24 h, 4 weeks, and 8 weeks. Three hundred and sixty molars and premolars were divided into four groups: ACTIVA™ BioACTIVE Restorative™, Filtek™ Bulk-Fill Restorative Composite, Tetric® N-Ceram Bulk-Fill Composite, and G-aenial® Composite. The normality of the data was determined with the Kolmogorov-Smirnov test, then the two-way ANOVA and Fisher's test were used for analyzing SBS data, and the Kruskal-Wallis and DSCF tests were conducted to analyze the microleakage. In the SBS test, there were no statistically significant differences between materials (p = 0.587), and the relation between material and time (p = 0.467), time points showed statistically significant differences (p = 0.016). As for the microleakage, statistically significant differences were found for all three time periods (p < 0.05), showing the conventional composite to have the lowest microleakage, followed by the bioactive material, and lastly the two bulk-fill composites. In conclusion, the new bioactive material has similar evaluated properties to bulk-fill composites (bond strength) and conventional composites (bond strength and microleakage) and can be used as an alternative restorative material. [ABSTRACT FROM AUTHOR]

Huda Hashim, Manal Hussain Abd-alla Department of Conservative Dentistry, College of Dentistry, Mustansiriyah University, Baghdad, IraqCorrespondence: Huda Hashim, Department of Conservative Dentistry, College of Dentistry, Mustansiriyah University, Baghdad, Iraq, Tel +9647717485368, Email cama43@uomustansiriyah.edu.iqObjective: To measure the repair shear bond strength (SBS) of an aged bulk-fill composite after different mechanical (diamond bur vs sandblasting) and chemical (universal adhesive with or without a previous silanization) surface treatments.Materials and Methods: Bulk-fill composite (Filtek One Bulk Fill, 3M ESPE) was used to construct seventy-two specimens aged through 10,000 thermal cycles. The specimens were allocated into two groups (n = 36 each) according to the mechanical roughening: Db, treated with a diamond bur, and Sb, treated by sandblasting. Each group was further subdivided into three subgroups (n = 12 each) according to the chemical conditioning: Db-only and Sb-only, unconditioned specimens; Db-U and Sb-U, specimens were conditioned with silane-containing universal adhesive (Scotchbond Universal adhesive, 3M ESPE); and Db-S-U and Sb-S-U, specimens were conditioned with a silane agent (Prosil, FGM) before employing the universal adhesive. The same composite material was used for repair. An additional reference group was constructed to measure the cohesive strengths of the bulk-fill composite. SBS testing was performed using a universal testing machine at a crosshead speed of 1 mm/min, and the failure modes were evaluated by stereomicroscope. The surface topography of resin composite after roughening was assessed by scanning electron microscopy. SBS data were statistically analyzed by ANOVA, Tukey’s test and independent t-test.Results: The significantly highest SBS was recorded in the reference group (P ≤ 0.05). Sb-only obtained significantly higher SBS than Db-only (P < 0.001). No significant difference in SBS was noted between Db-U and Sb-U or Db-S-U and Sb-S-U. Likewise, no significant difference was observed between the subgroups treated with or without silane (P > 0.05).Conclusion: The sandblasted specimens demonstrated a higher repair SBS than the diamond bur-treated specimens. The use of an additional silanizing step before applying silane-containing universal adhesive did not enhance the SBS of the repaired composite.Keywords: repair, bulk-fill composite, shear bond strength, silane, surface treatment, universal adhesive

This in vitro study aimed to compare the microleakage and marginal integrity of methacrylate/ormocer-based bulk-fill composite (BFC) restorations used in cervical marginal relocation with two different layering thicknesses in mesio-occlusal-distal (MOD) cavities exposed to thermo-mechanical loading. Standard MOD cavities were prepared in 60 mandibular molars and assigned into three groups: x-tra fil/AF + x-tra base/XB, Tetric N-Ceram Bulk Fill/TNB + Tetric N-Flow Bulk Fill/TFB, and Admira Fusion x-tra/AFX + Admira Fusion x-base/AFB. Each group was further divided into two subgroups (2 mm and 4 mm) based on the thickness of flowable BFCs (n = 10). The specimens were subjected to thermo-mechanical loading (240,000 cycles) and immersed in 0.2% methylene blue. Following mesiodistal sectioning, the specimens were examined under stereomicroscope (×25) and scored (0–3) for microleakage. Marginal integrity was examined using a scanning electron microscope (SEM). Descriptive statistical methods and the chi-square test were used to evaluate the data (p < 0.05). While there was no statistically significant difference in gingival cement microleakage in the XB and AFB specimens with a 4 mm thickness, microleakage was significantly increased in the TFB specimen (p = 0.604, 0.481, 0.018 respectively). A significantly higher amount of score 0 coronal microleakage was detected in the AFX2 mm + AFB4 mm compared to the TNB2 mm + TFB4 mm (p = 0.039). The SEM examination demonstrated better marginal integrity in groups with 2 mm thick flowable BFCs. Ormocer and methacrylate-based materials can be used in marginal relocation with thin layers. [ABSTRACT FROM AUTHOR]

Objectives: the aim of this study was to examine the stress distribution of enamel, dentin, and restorative materials in sound first molar teeth with restored cavities with conventional resin composites and bulk–fill composites, as well as to determine their fracture lifetimes by using the three-dimensional finite element stress analysis method. Materials and Methods: an extracted sound number 26 tooth was scanned with a dental tomography device and recorded. Images were obtained as dicom files, and these files were transferred to the Mimics 12.00 program. In this program, different masks were created for each tooth tissue, and the density thresholds were adjusted manually to create a three-dimensional image of the tooth, and these were converted to a STL file. The obtained STL files were transferred to the Geomagic Design X program, and some necessary adjustments, such as smoothing, were made, and STP files were created. Cavity preparation and adhesive material layers were created by transferring STP files to the Solidworks program. Finally, a FE model was created in the ABAQUS program, and stress distributions were analyzed. Results: when the bulk–fill composite and conventional resin composite materials were used in the restoration of the cavity, the structures that were exposed to the most stress as a result of occlusal forces on the tooth were enamel, dentin, restorative material, and adhesive material. When the bulk–fill composite material was used in restoration, while the restorative material had the longest fracture life as a result of stresses, the enamel tissue had the shortest fracture life. When the conventional resin composite material was used as the restorative material, it had the longest fracture life, followed by dentin and enamel. Conclusion: when the bulk–fill composite material was used instead of the conventional resin composite material in the cavity, the stress values on enamel, dentin, and adhesive material increased as a result of occlusal forces, while the amount of stress on the restorative material decreased. In the fracture analysis, when the bulk–fill composite material was used instead of the conventional resin composite material, a decrease in the number of cycles required for the fracture of enamel, dentin, and restorative materials was observed as a result of the forces generated in the oral cavity. [ABSTRACT FROM AUTHOR]

Purpose: Today, bulk-fill composites are used as a single layer with a thickness of up to 4-5 mm. However, is proper polymerization achieved with this increased thickness? Methods: This study was designed to investigate the effect of thickness on the degree of conversion (DC) (n = 6), the elution of monomers (n = 6), depth of cure (DoC) (n = 10) and cytotoxicity (n = 6) of the bulkfill composites SDR Flow Plus (SDR), SonicFill2 SingleFill (SF) and ACTIVA Bioactive Restorative (ACT) in comparison to the conventional G-aenial Posterior (GC). Two‐way analysis of variance (ANOVA) was used to assess the interaction between materials and surfaces, and one‐way ANOVA and Tukey tests were used to compare the degree of conversion, monomer elution and cytotoxicity values (P < 0.05). Results: The highest DC was found at the top surface of SDR, while the lowest DC was found at SF. The V2 mm/V0 mm DoC ratios of the composites except ACTs were appropriate according to the threshold. None of the composites were cytotoxic on day 1. Conclusion: In bulk-fill composites, DC decreased and monomer elution increased with increasing depth. The V4 mm/V0 mm ratios of all bulk-fill groups were not appropriate. Additionally, only ACTs had a cell viability of <70% on day 7. [ABSTRACT FROM AUTHOR]

Introduction This study aimed to compare the micro-shear bond strength (µSBS) performances of two resin-based calcium silicate-based cement (CSC) (TheraCal PT and TheraCal LC), Biodentine, and two modified-MTA CSC materials (NeoMTA 2 and BioMTA+) to bulk-fill restorative material. Materials and Methods Fifty 3D printed cylindrical resin blocks with a central hole were used (2 mm in depth and 4 mm in diameter). CSCs were placed in the holes (per each group n = 10) and incubated for 24 h. Cylindrical polyethylene molds (2 mm in height and diameter) were used to place the bulk-fill restorative materials on the CSCs and polymerize for 20 s. Then, all specimens were incubated for 24 h at 37 °C at a humidity of 100%. Specimen’s µSBSs were determined with a universal testing machine. Data were analyzed with one-way ANOVA (Welch) and Tamhane test. Results Statistically higher µSBS was found for TheraCal PT (29.91 ± 6.13 MPa) (p < 0.05) respect to all the other materials tested. TheraCal LC (20.23 ± 6.32 MPa) (p > 0.05) reported higher µSBS than NeoMTA 2 (11.49 ± 5.78 MPa) and BioMTA+ (6.45 ± 1.89 MPa) (p < 0.05). There was no statistical difference among TheraCal LC, NeoMTA 2 and Biodentine (15.23 ± 7.37 MPa) and between NeoMTA 2 and BioMTA+ (p > 0.05). Conclusion Choosing TheraCal PT as the pulp capping material may increase the adhesion and µSBS to the bulk-fill composite superstructure and sealing ability. [ABSTRACT FROM AUTHOR]

In the chronology of polymer-based composite materials, flowable bulk-fill composites represent the most recent development. They enable a significant reduction in treatment time by being applied in larger increments of 4 to 5 mm. The aim of the investigation was to assess the polymerization quality and mechanical performance of a new formulation that has just entered the market and was still in experimental formulation at the time of the investigation, and to compare these results in the context of clinically established materials of the same category. Adequate curing in increments of up to 4 mm could be confirmed both by profiling the elastoplastic material behavior of large increments in 100 µm steps and by real-time assessment of the degree of conversion and the associated polymerization kinetic. A slightly lower amount of filler in the experimental material was associated with slightly lower hardness and elastic modulus parameters, but the creep was similar and the elastic and total indentation work was higher. The kinetic parameters were assigned to the specific characteristics of each tested material. The mechanical macroscopic strength, evaluated in a three-point bending test and supplemented by a reliability analysis, met or exceeded the standards and values measured in clinically established materials, which for all materials is related to the higher flexibility of the beams during testing, while the modulus of elasticity was low. The low elastic modulus of all flowable bulk-fill materials must be taken into account when deciding the clinical indication of this material category.

Background: The most common dental materials are resin composite direct restorative materials and dentin adhesives, which are marketed with different techniques, application recommendations, and compositions, making it difficult to choose the most suitable material and method for different cases.

Introduction This study aimed to compare the micro-shear bond strength (µSBS) performances of two resin-based calcium silicate-based cement (CSC) (TheraCal PT and TheraCal LC), Biodentine, and two modified-MTA CSC materials (NeoMTA 2 and BioMTA+) to bulk-fill restorative material. Materials and Methods Fifty 3D printed cylindrical resin blocks with a central hole were used (2 mm in depth and 4 mm in diameter). CSCs were placed in the holes (per each group n = 10) and incubated for 24 h. Cylindrical polyethylene molds (2 mm in height and diameter) were used to place the bulk-fill restorative materials on the CSCs and polymerize for 20 s. Then, all specimens were incubated for 24 h at 37 °C at a humidity of 100%. Specimen’s µSBSs were determined with a universal testing machine. Data were analyzed with one-way ANOVA (Welch) and Tamhane test. Results Statistically higher µSBS was found for TheraCal PT (29.91 ± 6.13 MPa) (p < 0.05) respect to all the other materials tested. TheraCal LC (20.23 ± 6.32 MPa) (p > 0.05) reported higher µSBS than NeoMTA 2 (11.49 ± 5.78 MPa) and BioMTA+ (6.45 ± 1.89 MPa) (p < 0.05). There was no statistical difference among TheraCal LC, NeoMTA 2 and Biodentine (15.23 ± 7.37 MPa) and between NeoMTA 2 and BioMTA+ (p > 0.05). Conclusion Choosing TheraCal PT as the pulp capping material may increase the adhesion and µSBS to the bulk-fill composite superstructure and sealing ability.

INTRODUCTION: High-viscosity bulk-fill composites may polymerize insufficiently at deep layers after a short curing time. OBJECTIVES: This in-vitro study aimed to estimate and compare the degree of conversion (DC) and micro-hardness (MH), following 20 and 40 seconds photopolymerization of three high-viscosity bulk-fill composites at 2-4 mm depth. MATERIAL AND METHODS: Three new brands of bulk-fill dental composites were selected for this study, including Beautifil-Bulk (Shofu Inc., Kyoto, Japan), Tetric N-Ceram Bulk Fill (Ivoclar Vivadent AG, Schaan, Liechtenstein), and Opus Bulk Fill (FGM, Joinville, SC, Brazil). For each composite, six disc samples located at a 2-4 mm depth were prepared via photopolymerization for 20 (n = 3) or 40 (n = 3) seconds. Each sample was 2 mm thick and 8 mm wide. Following one-hour post-cure, DC and MH assessments were applied using Fourier transform infrared spectroscopy (FTIR) and Vickers MH devices. Data were analyzed using parametric ANOVA and LSD tests. RESULTS: Values of DC and MH were higher following 40 seconds compared with 20 seconds photopolymerization. However, none of the composites reached the minimum accepted DC (≥ 55%). For both curing times, Tetric N-Ceram showed the highest DC% (42%, 51%), while Beautifil-Bulk had the highest MH values for top (58.2 ± 0.5, 60.0 ± 1.5) and bottom (47.5 ± 3.1, 53.5 ± 1.0) surfaces. CONCLUSIONS: At a 2-4 mm depth and one-hour post-cure, bulk-fill composites showed insufficient DC and low MH values when photopolymerized for 20 or 40 seconds. The extension of curing time to 40 seconds improved the DC and MH values. [ABSTRACT FROM AUTHOR]

Aim: As the spectrum of composite materials expands in the dental market, it's becoming more challenging to differentiate the structural properties and to find suitable finishing-polishing (f-p) materials. The main goal is to evaluate the impact of one and multi-step f-p systems on the surface roughness (SR) of current composite materials. Methodology: In this study, nanohybrid bulk-fill (Filtek Bulk Fill Posterior [FBFP]), nanohybrid (Ceram.x One [CXO]), microhybrid (Filtek Z250 [FZ250]), and giomer bulk-fill (Beautifil Bulk Restorative [BBR]) composites were tested. After sample preparation and 24-h storage in 37 °C distilled water, each main group was assigned to one of two groups (n = 10): a one-step (One Gloss-PS) or a multi-step (Sof-Lex) f-p system. SR values (Ra, µm) were measured using a profilometer. Statistical analysis was done using Tukey HSD and ANOVA tests (p < 0.05). Results: FZ250 showed the highest Ra values, regardless of the f-p system used. CXO showed statistically significantly lower SR scores than FZ250 (p < 0.05). There were no significant differences among the Ra values of the one- or multi-step f-p systems for FBFP and FZ250. Both the material and f-p systems had a significant effect on the Ra values separately. Conclusion: FZ250 showed the highest Ra values, and composites polished with the multi-step f-p system exhibited slightly smoother surfaces than those polished with the one-step system. [ABSTRACT FROM AUTHOR]

Abstract Background Preheating is one of several innovative approaches and improvements developed to increase the durability and clinical behavior of resin composites. Development of preheated composites is to reduce its viscosity in order to improve resin composite adaptation and placement ease. The purpose of this clinical trial was to study the effect of preheating Bis-GMA free and Bis-GMA-containing resin composites at different temperatures on the pulpal floor and restoration temperature. A total of twenty individuals (N = 40) have two carious posterior teeth that need to be restored were randomly assigned to one of two groups based on the type of restorative materials used: (group 1) Bis-GMA-containing resin composite VisCalor bulk (VCB), and (group 2) Bis-GMA-free resin composite Admira Fusion x-tra (AFX). Preheating temperatures of 50 °C and 70 °C were utilized to separate each group into two subgroups. Class I or II cavities were prepared. Thermometer device with two separate K-type temperature probes was used to measure the base line temperature values at the pulpal floor before beginning the restorative procedure (C 0 ), pulpal floor during packing of preheated composite (C 1 ), the top composite surface after packing and before curing (C 2 ), pulpal floor after curing of the preheated composite (C 3 ), and top composite surface after curing (C 4 ). One-way ANOVA and the Kruskal–Wallis test were used to analyze the data. Results The measured temperature of pulpal floor for both preheated VCB or AFX at 50 °C or 70 °C revealed significant increasing from base line measured temperature to during packing as well as after curing with (P-value

Objectives: The aim of this in-vitro study is to investigate discoloration of the composite resins with different characteristics which were colored by immersing in coffee, kept in mouthwashes with and without hydrogen peroxide. Materials and Methods: In this study, 18 samples (6 mm x 2 mm) pre-heated bulk-fill (Viscalor Bulk -(VIS)), dual-cured (Fill Up!-(FUP)) bulk-fill and a microhybrid composite resin (G-aenial posterior-(GCP)) were prepared. After the samples were kept in distilled water for 24 hours, baseline colour measurements were performed with a spectrophotometer. ΔE001 color measurements were made of the samples immersed in coffee for 7 days. The samples were divided into two groups to be kept in mouthwashes with hydrogen peroxide (Crest 3D White) and without hydrogen peroxide (Listerine Advance White) (n=9). ΔE002 color measurements were applied after kept in whitening mouthwashes for 24 hours. Discoloration were calculated with the CIEDE2000 formula. Data were statistically analysed with One-way ANOVA and post hoc tukey tests (p

Aim: This study aims to evaluate and compare the clinical performance of two restorative materials – bioactive resin-modified glass ionomer (ACTIVA BioACTIVE restorative) and giomer hybrid composite (Beautifil Flow Plus) in restoring class I carious primary molars. Materials and Methods: The split-mouth randomized controlled study was conducted on 100 primary molars from 50 children (28 – males, 22 – females) from 50 children in age range of 5-9 years (Mean-7.29±1.34) with at least two occlusal carious lesions on either maxillary or mandibular primary molars. Each child had both the control and the experimental teeth restored with respective restorative materials, Group I (Control, n = 50) → Giomer, Group II (Experimental, n = 50) → Bioactive resin-modified glass ionomer. The restorations were evaluated by two independent investigators using modified United State Public Health Service criteria at immediate postoperative, 6 months, and 12 months. The Chi-square test was used for the statistical analysis after collecting the data. Results: At the 12-month follow-up, 33 children (66 teeth) reported with an attrition rate of 33%. The color match between the groups was not statistically significant at all intervals. The marginal discoloration, marginal integrity, anatomic form, and retention had no significant difference at 6 months. But at 12 months, there was a statistically significant difference between the groups with p value of 0.04,

Background/purpose: Cuspal deflections in composite restoration have been investigated with considering wall compliance of human tooth cavity and light-curing protocol. The purpose of this study was to investigate effects of mold wall compliance and radiant emittance of LED light on the wall deflection of simulated aluminum mold cavities restored with a bulk-fill composite. Materials and methods: Sixty aluminum molds simulating a class II mesio-occluso-distal (MOD) cavity (6 W × 8 L × 4 D mm; W, width; L, length; D, Depth) were prepared and allocated to three groups with varying mold wall thicknesses of 1, 2, and 3 mm. The molds were bulk-filled with a bulk-fill composite and photo-cured. Four light-curing protocols were used: three duty ratios/exposure times: 100%/20 s, 50%/40 s, or an increasing mode (0 → 100%)/40 s with a pulse width modulated (PWM) LED curing light and one 20 s exposure time with a commercial LED light. Results: Mean mold wall deflection at 2000 s decreased with increasing mold wall thickness (1, 2, and 3 mm) (p 0.05). However, in the 3-mm-thick mold, wall deflections with low radiant emittance were significantly lower than those with high radiant emittance (p

In this study, a novel method for simulating human teeth was developed, with which the effect of radiant emittance of an LED curing light on the cuspal deflection was investigated. A mesio-occluso-distal (MOD) cavity was replicated using a heat-pressed ceramic and lost wax technique, and the cuspal compliance and cuspal deflection of the replicated ceramic teeth and extracted human teeth were evaluated. The replicated ceramic teeth were restored using a nano bulk-fill composite and photopolymerized using three different protocols. Data were analyzed with t-test and one-way ANOVA (α=0.05). The cuspal compliance and cuspal deflection of the replicated ceramic teeth and extracted human teeth were similar. Cuspal deflections did not differ significantly among the tested photopolymerization protocols. Thus, the replicated ceramic teeth were an effective simulation of human teeth. During bulk-fill composite restoration of the MOD cavity, cuspal deflection was not affected by changing the radiant emittance of the LED light. [ABSTRACT FROM AUTHOR]

Background: The aim of this split-mouth design research was to compare the clinical performance of a glass-ionomer cement system on Class I/II cavities against the clinical performance of bulk-fill resin composite restoration materials. Methods: Thirty-five patients were randomized and enrolled in the study, aged between 10 and 12 years, all of whom had a matched pair of permanent mandibular carious molars with similar Class I/II. A total of 70 restoration placements were performed. The patients were each given two restorations consisting of either a glass-ionomer cement with a nano-filled coating or a bulk-fill resin composite after the use of a self-etch adhesive. The cumulative survival rates were estimated using log-rank test and the Kaplan–Meier method. For comparison of the restorative materials in line with the modified Ryge, the McNemar test and the Wilcoxon signed rank test were employed. Results: With regard to retention, the glass-ionomer cement system and bulk-fill resin composite performed similarly in permanent molars in Class I/II cavities over a period of up to 24-months (p > 0.05). Over the 24-month period, Class I restorations showed statistically better survival rates than Class II restorations (p < 0.05). In the case of glass-ionomer cement systems, over the two-year period, more common chipping and surface degradations were observed. Conclusions: The glass-ionomer cement system and bulk-fill resin composite restorative materials display good clinical performance over a period of 24-months. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the postoperative sensitivity (POS), as well as the clinical performance of posterior restorations using a new chemically-cured bulk-fill composite (Stela Automix and Stela Capsule, SDI) comparing with a light-cured bulk-fill composite after 6 months., Methods: Fifty-five participants with at least three posterior teeth needing restoration were recruited. A total of 165 restorations were performed on Class I or Class II cavities. After the application of Stela primer, the chemically-cured composite (Stela Automix or Stela Capsule) was inserted. For the light-cured composite group, a universal adhesive (Scotchbond Universal) was applied with a bulk-fill composite (Filtek One). Participants were evaluated for spontaneous and stimulated POS in the baseline, after 48 h, 7 days, and 6 months. Additionally, each restoration was assessed using the updated version of FDI criteria after 6 months. The differences in the proportions of the groups were compared by Cochran test statistics (α = 0.05)., Results: Both chemically-cured composites showed a lower risk of POS compared to the light-cured composite at baseline and up to 48 h (p < 0.04). A significantly lower surface luster and texture was observed for the Stela Capsule composite compared to the light-cured bulk-fill composite (baseline and 6 months; p = 0.03). A significant color mismatch was observed for the light-cured bulk-fill composite compared to the chemically-cured composites (baseline and 6 months; p = 0.03). No significant differences were observed in any other item evaluations (p > 0.05)., Conclusion: Chemically-cured composites exhibit lower postoperative sensitivity and less color mismatch compared to a light-cured bulk-fill composite after 6 months of clinical service., Clinical Significance: The chemically-cured composites appear to be an appealing option for restoring posterior teeth, as they exhibit lower postoperative sensitivity compared to a light-cured bulk-fill composite, both at baseline and up to 48 h, and less color mismatch., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

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

Context: Due to advancements in adhesive technology and the introduction of fiber reinforcement, there has been a paradigm shift towards a more minimally invasive approach in coronal restoration of endodontically treated teeth., Aims: This research aimed to evaluate and compare fracture resistance of postendodontic restoration using a self-adhesive bioactive resin and a bulk-fill composite with or without resin-impregnated glass fibers., Materials and Methods: Mesio-occlusal-distal cavities were prepared on 80 extracted human maxillary premolars. Root canal treatment was completed following standard access cavity preparation. Then, the teeth were divided into two groups based on the composite used for postendodontic restoration. Group I: Bulk-fill composite (Tetric N-Ceram). Group II: Activa BioActive. Group I and Group II were then divided into two subgroups depending on fiber incorporation ( n = 20). Subgroup IA: Bulk-fill composite. Subgroup IB: Bulk-fill composite with fiber incorporation. Subgroup IIA: Activa BioActive. Subgroup IIB: Activa BioActive with fiber incorporation. The force required to fracture the teeth was recorded using the universal testing machine., Statistical Analysis Used: Two-way ANOVA and Tukey's multiple post hoc test., Results: Activa BioActive with fiber incorporation showed the highest mean fracture resistance (988.52N). Bulk-fill composite without fiber incorporation had the least mean fracture resistance (669.87N)., Conclusions: Activa BioActive bulk-fill restorative material when used with the incorporation of resin-impregnated glass fibers can be a preferred material of choice for restoring endodontically treated teeth., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Journal of Conservative Dentistry and Endodontics.)

INTRODUCTION: The aim of this study was to evaluate the effect of exposure of bulk-fill composite resin to 2 different acidic beverages for 1 day, 7 days and 30 days on the refractive index value. METHODS: A total of 36 specimens made from standardized disc shaped SDR Plus (Dentsply Sirona, Konstanz, Germany) universal bulk-fill composite resin was prepared. Samples were divided into three groups as distilled water (control), coke and orange juice (n = 12). Refractive index (nD) measurements were made with an Abbe refractometer. After the first measurement, samples were kept in an oven at 37 ° C in bottles for the relevant beverages in distilled water, coke and orange juice groups on the 1st day, 7th day and 30th day. nD values were tested by generalized analysis of variance. RESULTS: The average value obtained in n30 was obtained lower than the others. There is no difference between the average values in the first 3-time period. Group and time interaction was statistically significant. The mean value of n30 in the control group was lower than at other times. In the coke group, the average value obtained in n30 was obtained lower than other times. There is also a statistical difference between n7 and n1. There is also a difference between nilk and n30 and n7 in the orange group. DISCUSSION AND CONCLUSION: Acidic beverages decrease the refractive index value of bulk-fill composite resins at the end of the 30th day. This decrease occurs most often in samples exposed to coke.

Bioactive materials have emerged as a promising alternative to conventional restorative materials as part of more conservative dentistry. The aim of this study was to evaluate and compare the shear bond strength (SBS) and microleakage of a new bioactive restorative material, two bulk-fill restorative composites, and a conventional composite at 24 h, 4 weeks, and 8 weeks. Three hundred and sixty molars and premolars were divided into four groups: ACTIVA™ BioACTIVE Restorative™, Filtek™ Bulk-Fill Restorative Composite, Tetric® N-Ceram Bulk-Fill Composite, and G-aenial® Composite. The normality of the data was determined with the Kolmogorov-Smirnov test, then the two-way ANOVA and Fisher’s test were used for analyzing SBS data, and the Kruskal-Wallis and DSCF tests were conducted to analyze the microleakage. In the SBS test, there were no statistically significant differences between materials (p = 0.587), and the relation between material and time (p = 0.467), time points showed statistically significant differences (p = 0.016). As for the microleakage, statistically significant differences were found for all three time periods (p < 0.05), showing the conventional composite to have the lowest microleakage, followed by the bioactive material, and lastly the two bulk-fill composites. In conclusion, the new bioactive material has similar evaluated properties to bulk-fill composites (bond strength) and conventional composites (bond strength and microleakage) and can be used as an alternative restorative material.

Aim: The aim of this study is to investigate the effect of different ground)based coffee types on the color change of nanohybrid and bulk-fill composites. Methodology: A total of 80 disk-shaped samples were made using Teflon molds (5 mm in diameter and 8 mm thick) and two types of A2 resin with nanohybrid (Tetric N Ceram Ivoclar Vivadent, Schaan, Liechtenstein) and bulk-fill (Filtek Bulk-Fill, 3M ESPE, St. Paul, MN, USA) structures. All samples were finished and polished with four-stage (thick, medium, fine, and superfine) polishing disks (Sof-lex, 3M ESPE, St. Paul, MN, USA) and kept at 37°C for 24 hours. Color measurements of the samples were performed using a spectrophotometer (Vita Easy Shade, Vita ZahnFabrik, Bad Sackingen, Germany) and were divided into subgroups: the control group, filter coffee, Turkish coffee, espresso, and Mırra (n = 8). Distilled water was used as a control. Prepared coffees were added to the microcentrifuge tubes and refreshed daily during the 14-day exposure period. ΔE values were calculated for each material. Statistical analyses were performed using one-way variance analysis and Tukey multiple comparisons (p = 0.05). Results: There was no significant color change for either the nano-fill or bulk-fill composite groups in the control group samples (p>0.05). Filter coffee was found to be the most effective colorant coffee type for both composites (p < 0.05). Among the coffee types, Mırra caused the least coloration for both composites. Conclusion: The consumption of two or more cups of coffee per day, especially filter coffee, can cause color changes in both conventional and bulk-fill composites, and it should be considered an important factor in aesthetic problems with dental restorations. [ABSTRACT FROM AUTHOR]

The objective of the study was to evaluate the effect of different restorative protocols on fracture resistance of root canal-treated molars. 48 mandibular first molars were used and divided into six groups (n = 8); G1 (negative control): teeth kept intact. G2 (positive control): teeth had root canal treatment and standard MOD cavity preparations but kept unrestored. G3: prepared as G2 and directly restored with VitaEnamic ceramic overlays (CO). G4: as G3, but the pulp chamber was restored first with smart dental restorative (SureFil SDR flow = SDR) bulk-fill flowable composite base. G5: as G3, but the pulp chamber was restored first with SonicFill (SF) bulk-fill composite base. G6: as G3, but the pulp chamber was restored first with a fiber-reinforced composite (FRC) base. All samples were subjected to thermocycling between 5 °C and 55 °C in a water bath for a total of 2000 cycles with 10 s dwell time. Then specimens were individually mounted on a computer-controlled testing machine with a load cell of 5 kN, and the maximum load to produce fracture (N) was recorded. Data were analyzed using one-way ANOVA followed by Tukey's post hoc test (P = 0.05). There was a significant difference between the groups (P < 0.001). Teeth restored with FRC and ceramic overlays had the highest load-bearing capacity. Pulp chamber restoration with either FRC or SDR before ceramic overlay fabrication provided significantly better tooth reinforcement than ceramic overlay alone (P < 0.001). Fracture modes were analyzed to determine the type of fracture as repairable or catastrophic, where FRC + CO and SDR + CO groups had favorable fracture modes that were mostly repairable. When restoring root canal-treated molars with overlays, the pulp chamber should be sealed with either FRC or SDR to ensure the best possible fracture resistance. The clinical relevance of the study is that a new simple restorative protocol is presented to enhance the survival of root canal-treated molars using ceramic overlays. [ABSTRACT FROM AUTHOR]

Aim: This study aims to evaluate and compare the clinical performance of two restorative materials - bioactive resin-modified glass ionomer (ACTIVA BioACTIVE restorative) and giomer hybrid composite (Beautifil Flow Plus) in restoring class I carious primary molars.Materials and Methods: The split-mouth randomized controlled study was conducted on 100 primary molars from 50 children (28 - males, 22 - females) from 50 children in age range of 5-9 years (Mean-7.29±1.34) with at least two occlusal carious lesions on either maxillary or mandibular primary molars. Each child had both the control and the experimental teeth restored with respective restorative materials, Group I (Control, n = 50) → Giomer, Group II (Experimental, n = 50) → Bioactive resin-modified glass ionomer. The restorations were evaluated by two independent investigators using modified United State Public Health Service criteria at immediate postoperative, 6 months, and 12 months. The Chi-square test was used for the statistical analysis after collecting the data.Results: At the 12-month follow-up, 33 children (66 teeth) reported with an attrition rate of 33%. The color match between the groups was not statistically significant at all intervals. The marginal discoloration, marginal integrity, anatomic form, and retention had no significant difference at 6 months. But at 12 months, there was a statistically significant difference between the groups with p value of 0.04,<0.001,<0.02 and <0.001 respectively. respectively. At 12 months, there was no postoperative sensitivity in both groups.Conclusion: Bioactive resin-modified glass ionomer with enhanced properties can be used as an effective restorative material, especially in children with excessive salivation. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the effect of brushing with two whitening dentifrices (Colgate Optic White (COW) and Colgate Optic White Charcoal (COC)) on surface gloss, micro-roughness, and micro-hardness of nanostructured hybrid conventional (Z350) and bulk-fill (Tetric N Ceram bulk-fill) polymer composite. In total, 96 disk samples using two nano-hybrid composite polymers (Z350 and Tetric N Ceram Bulk-fill) were prepared. All specimens were exposed to two different dentifrices (COW and COC), resulting in four main subgroups in the study. Specimens were assessed for surface gloss, micro-roughness (Ra), and micro-hardness using standardized methodology. Means and standard deviations of properties compared using paired t-test, one-way and two-way ANOVA, and post hoc test. The presence of dentifrices did not show any significant difference in micro-hardness values of Z350 (p > 0.05), whereas micro-hardness of bulk-fill composite significantly reduced on dentifrices exposure (p ≤ 0.05). Bulk-fill polymer composite showed significant reduction in gloss after dentifrice exposure (p < 0.05), however, Z350 showed no significant loss of gloss due to dentifrices (p > 0.05). A significant increase in Ra was observed for both resin materials after exposure to dentifrices (COC and COW). Conventional resin composite (Z350) showed comparable surface hardness and gloss before and after dentifrice exposure, however, micro-roughness increased significantly due to dentifrice exposure. Bulk-fill resin (Tetric N Ceram) showed significant loss of micro-hardness and gloss and increase in micro-roughness on dentifrice exposure. Conventional nano-hybrid composite polymer showed better durability in resisting loss of surface properties compared to bulk-fill resin polymer in the present experiment. [ABSTRACT FROM AUTHOR]

Objectives: the aim of this study was to examine the stress distribution of enamel, dentin, and restorative materials in sound first molar teeth with restored cavities with conventional resin composites and bulk–fill composites, as well as to determine their fracture lifetimes by using the three-dimensional finite element stress analysis method. Materials and Methods: an extracted sound number 26 tooth was scanned with a dental tomography device and recorded. Images were obtained as dicom files, and these files were transferred to the Mimics 12.00 program. In this program, different masks were created for each tooth tissue, and the density thresholds were adjusted manually to create a three-dimensional image of the tooth, and these were converted to a STL file. The obtained STL files were transferred to the Geomagic Design X program, and some necessary adjustments, such as smoothing, were made, and STP files were created. Cavity preparation and adhesive material layers were created by transferring STP files to the Solidworks program. Finally, a FE model was created in the ABAQUS program, and stress distributions were analyzed. Results: when the bulk–fill composite and conventional resin composite materials were used in the restoration of the cavity, the structures that were exposed to the most stress as a result of occlusal forces on the tooth were enamel, dentin, restorative material, and adhesive material. When the bulk–fill composite material was used in restoration, while the restorative material had the longest fracture life as a result of stresses, the enamel tissue had the shortest fracture life. When the conventional resin composite material was used as the restorative material, it had the longest fracture life, followed by dentin and enamel. Conclusion: when the bulk–fill composite material was used instead of the conventional resin composite material in the cavity, the stress values on enamel, dentin, and adhesive material increased as a result of occlusal forces, while the amount of stress on the restorative material decreased. In the fracture analysis, when the bulk–fill composite material was used instead of the conventional resin composite material, a decrease in the number of cycles required for the fracture of enamel, dentin, and restorative materials was observed as a result of the forces generated in the oral cavity.

This in vitro study aimed to compare the microleakage and marginal integrity of methacrylate/ormocer-based bulk-fill composite (BFC) restorations used in cervical marginal relocation with two different layering thicknesses in mesio-occlusal-distal (MOD) cavities exposed to thermo-mechanical loading. Standard MOD cavities were prepared in 60 mandibular molars and assigned into three groups: x-tra fil/AF + x-tra base/XB, Tetric N-Ceram Bulk Fill/TNB + Tetric N-Flow Bulk Fill/TFB, and Admira Fusion x-tra/AFX + Admira Fusion x-base/AFB. Each group was further divided into two subgroups (2 mm and 4 mm) based on the thickness of flowable BFCs (n = 10). The specimens were subjected to thermo-mechanical loading (240,000 cycles) and immersed in 0.2% methylene blue. Following mesiodistal sectioning, the specimens were examined under stereomicroscope (×25) and scored (0–3) for microleakage. Marginal integrity was examined using a scanning electron microscope (SEM). Descriptive statistical methods and the chi-square test were used to evaluate the data (p < 0.05). While there was no statistically significant difference in gingival cement microleakage in the XB and AFB specimens with a 4 mm thickness, microleakage was significantly increased in the TFB specimen (p = 0.604, 0.481, 0.018 respectively). A significantly higher amount of score 0 coronal microleakage was detected in the AFX2 mm + AFB4 mm compared to the TNB2 mm + TFB4 mm (p = 0.039). The SEM examination demonstrated better marginal integrity in groups with 2 mm thick flowable BFCs. Ormocer and methacrylate-based materials can be used in marginal relocation with thin layers.