Tetric N-Flow Research Articles

Fracture Resistance in Fibre-Reinforced Resin Composite Restorations in Deciduous and Permanent Molars: An Ex Vivo Study

AimThe aim of this study was to compare the fracture resistance levels of restored deciduous teeth and permanent molars restored with different materials, including ultra-polyethylene fibre tape (Ribbond-Ultra), fibre-reinforced resin composite EverX posterior, fibre-reinforced flowable resin composite EverX Flow and bulk-fill flow restorative material (Tetric N-flow) in the posterior region. MethodsWe tested sixty-four caries-free human mandibular molars (32 deciduous molars and 32 permanent molars). Deep and wide Class I cavities were prepared in each tooth. The teeth were embedded in poly(methyl methacrylate) resin up to the cementoenamel junction, leaving the crown completely exposed. Oral temperature fluctuations were then simulated using two thousand thermocycling cycles, each lasting 30 seconds in the hot phase (approximately 35 °C). The loading rate for our force-fracture tests was set at 0.5 mm/min. Direct restorations were made using a spherical tip and applying the force perpendicular to the sample surface. Visual inspection of the fractured specimens, in combination with adhesive scanning electron microscopy (SEM) and finite element analysis (FEA), provided detailed insights into the failure modes and stress distribution at the restoration–tooth interface. ResultsTeeth restored with fibre-reinforced composite (EverX Posterior) had the highest fracture resistance, followed by fibre-reinforced flowable resin composite (EverX Flow). Teeth restored with the ultra- polyethylene fibre tape (Ribbond-Ultra), followed by the flowable bulk-fill composite (Tetric N-flow) had the lowest resistance. Statistical analysis revealed significant differences between the groups, except for EverX Posterior and EverX Flow. A predictive algorithm was also proposed for the likelihood of restoration failure. ConclusionModern fibre-reinforced resin composites, such as EverX Posterior, effectively reinforce teeth against fractures, with success in both restored deciduous and permanent molars. Meanwhile, the use of polyethylene fibre tapes is less effective, and they involve a time-consuming application.

Mechanical properties of combined packable and high-filled flowable composite used for the fixed retainer: an in vitro study

BackgroundClinicians often utilize both flowable and packable composites concurrently in bonding fixed retainers. Thus, this study aimed to assess the synergistic effect of these composites in the bonding process.MethodsThis in vitro study divided specimens into three groups: flowable composite (nano-hybrid, Tetric N-Flow, Ivoclar Vivadent), packable composite (nano-hybrid, Tetric N-ceram, Ivoclar Vivadent), and combined use of flowable and packable composite. Shear bond strength (SBS), adhesive remnant index (ARI), and wire pull-out resistance were compared among the groups. Statistical analyses were conducted using ANOVA and Tukey tests to compare study groups. Additionally, Chi-square and Kruskal-Wallis tests were employed to analyze the ARI index among the groups.ResultsANOVA results indicated no statistically significant differences among test groups (P = 0.129) regarding SBS. However, a significant difference existed between flowable and packable composite groups (P = 0.01) regarding ARI scores. Among the study groups, flowable composite exhibited the highest frequencies of ARI scores of 1 and 2, whereas packable composite showed the highest frequency of ARI scores of 0. The combined group had higher frequencies of ARI scores of 0 and 1 compared to the flowable composite. The wire pull-out test revealed that the combined application of flowable and packable composite resulted in significantly lower detachments compared to the packable composite alone (P = 0.008). However, no significant differences were observed in the comparisons between the flowable-packable (P = 0.522) and combined-flowable (P = 0.128) groups.ConclusionThe combined use of flowable and packable composites for fixed retainers demonstrated adequate shear bond strength and ideal ARI scores, suggesting it as a suitable adhesive system for bonding orthodontic fixed retainers.

Comparative Evaluation of Fracture Resistance of Composite Core Buildup Materials: An In Vitro Study.

Aim This study aimed to compare the fracture resistance of different materials used in composite core buildups, including conventional filler composite, nanofiller composite, and short fiber-reinforced composite (SFRC). Methods This in vitro study was conducted on 30 freshly extracted premolars. The teeth were treated using a uniform endodontic procedure, and Fiber Posts (REFORPOST, Angelus) were placed. The teeth were then divided into three groups and restored using different materials. Group 1 was restored using SFRC(everX Posterior, GC, Europe), Group 2 using microfiller composite (Te-Econom Flow, Ivoclar Vivadent), and Group 3 using nanofiller composite (Tetric N-Flow, Ivoclar Vivadent). The restoration materials were then light-cured for 40 seconds. The teeth were placed in a Universal Testing Machine (Instron) and a load was applied with a stainless-steel ball (4 mm diameter) until the tooth fractured. The fracture load for each tooth was recorded, and after the mechanical test, the experimental groups were examined for failure modes. Statistical analysis was performed using SPSS version 21.0 software. A one-way ANOVA test was conducted to compare more than two groups, followed by Tukey's test for post hoc pairwise comparison. Results The mean fracture resistance of the microfiller composite (346.94±44.63) was the lowest among the three groups. When analyzed using Tukey's test at p<0.05, fracture resistance was significantly higher in the SFRC, followed by nanofillers and microfiller composites. Conclusion Due to the increasing demand for aesthetic restorations in recent years, composites have become important in modern restorative dentistry. The development and implementation of composite dental restorative materials rely on a comprehensive understanding of each composite component and consideration of methods for modifying each component. As a result, the findings of this study will be beneficial in determining which material to use based on specific cases.

Color behavior of composite resin enhanced with different shapes of new antimicrobial polymer coated nanoparticles

BackgroundZein-coated magnesium oxide nanoparticles (zMgO NPs) demonstrate a potent antimicrobial effect, endorsing it as a compelling additive to dental materials formulations for oral health care advances. However, currently there is no data on the imprint of zMgO NPs on the color permanence of dental composites. The objective of this study is to evaluate the color stability of different types of composite enhanced with antimicrobial zein-coated magnesium oxide nanoparticles (zMgO NPs) of different shapes before and after thermocycling.MethodsTwo hundred composite samples were divided into four groups: Gp1: Tetric N-Flow with zMgO nanowires, Gp2: Tetric N-Flow with zMgO nanospheres, Gp3: Tetric N-Ceram with zMgO nanowires; Gp4: Tetric N-Ceram with zMgO nanospheres. Each group was subdivided into 5 subgroups (n = 10) with concentrations of zMgO NPs 0%, 0.3%, 0.5%, 1% and 2%. The characterization of the modified composite containing the zMgO was done via X-ray Diffraction, Field Emission Scanning Electron Microscopy (FESEM), and Fourier Transform Infrared Spectroscopy (FTIR). Colorimetric evaluation was performed through spectrophotometry with a white background. Samples underwent color assessment using a spectrophotometer, followed by thermocycling, and then another color assessment.ResultsFESEM analysis showed a uniform distribution of the zMgO nanoparticles in the composite and FTIR illustrated no change in the spectra. However, the XRD spectra exhibited an amorphous pattern in the composite enhanced with zMgO NPs. There was no compelling discrepancy in color variation ΔE among the different groups before and after thermocycling (p > 0.05). A statistically notable variation in ΔL was found amid the control and N-Flow and N-Ceram with 2% zMgO nanospheres before and after thermocycling respectively (p < 0.05). While after thermocycling, there was a statistically significant difference in Δa in N-Flow and N-Ceram wires amid the control and the different groups (p < 0.05). Additionally, after thermocycling there was a statistically significant difference in Δb in N-Flow and N-Ceram wires between the control and the different groups (p < 0.05). The Tukey test exhibited no variation among the groups with different zMgO concentrations (p > 0.05).ConclusionEnhancing N-Flow and N-Ceram composite with antimicrobial zMgO nanowires and nanospheres did not alter the total color stability of the materials before and after thermocycling.

Comparison of the bond strength of five different composites used in the production of clear aligner attachments

AimThe aims of this study were to measure and compare shear bond strength (SBS) and manipulation time (MT) among five different composite resins (CR; two flowable and three highly viscous) which are used in the production of clear aligner attachments. Material and methodsThis in vitro experiment study comprised of 150 extracted premolars which were divided into 5 equal groups. Predictor variables were CRs; Tetric Evo Ceram (Ivoclar VivadentAG, Liechtenstein) (Group 1), Tetric NCeram; (Ivoclar VivadentAG, Liechtenstein) (Group 2), Tetric N-Flow (GC Dental Products, Tokyo, Japan) (Group 3), G-aenial Universal Injectable (GC Dental Products, Tokyo, Japan) (Group 4), GC Aligner Connect (GC Dental Products, Tokyo, Japan) (Group 5), respectively. Outcome variables were; SBS and MT for each CR attachment in each group of teeth. Oneway ANOVA was used to compare the groups. Levene's test was used to determine variance homogeneity. In terms of variance homogeneity, Bonferroni tests were used as a post-hoc test for multiple group comparisons. Results: SBS was statistically different between study groups (p < 0.001). Average SBS values ​​are found to be 16.6 ± 3.6 MPa for Tetric Evo Ceram; 20.7 ± 5.4 MPa for Tetric NCeram; 21.0 ± 4.0 MPa for Tetric N-Flow; 18.9 ± 5.0 MPa for G-aenial Universal Injectable; and 17.4 ± 3.5 MPa for GC Aligner Connect. The values ​​in the Tetric Evo Ceram group were significantly lower than the Tetric N-Ceram group (p = 0.004) and the Tetric N-Flow group (p = 0.001). Mean value of shear bond strength in the GC Aligner connect group were significantly lower than in the Tetric N-Ceram group (p = 0.047) and in the Tetric N-Flow group (p = 0.017). Flowable composite had a significantly shorter manipulation time than the high viscous one; mean 1,08 ± 0,22 min to mean 4,57 ± 0,51 min, respectively. ConclusionAlthough SBSs of CRs tested in the study was found to be statistically different, they all quite exceeded the accepted clinically sufficient value of 6–8 MPa. Besides, flowable composite required substantially less time to manipulate than the high viscosity composite.

Microleakage and Marginal Integrity of Ormocer/Methacrylate-Based Bulk-Fill Resin Restorations in MOD Cavities: SEM and Stereomicroscopic Evaluation.

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.

Effect of Ceramic Thickness on Light Attenuation, Degree of Conversion, Knoop Hardness, and Elastic Modulus of Four Luting Resins.

This study evaluated the influence of the thickness of disilicate ceramic on the light attenuation (mW/cm2), degree of conversion (DC, %), Knoop hardness (KH, N/mm2) and the elastic modulus (E, MPa) of four luting resins. Three resin cements: RelyX Veneer (RV, 3M Oral Care, Monrovia, CA USA); Allcem Veneer APS (AC, FGM); Variolink Esthetic LC (VE, Ivoclar Vivadent, Schaan, Liechtenstein) and one flowable resin composite Tetric N-Flow (TF, Ivoclar Vivadent) were photocured for 20 seconds. The irradiance (mW/cm2) and emission spectrum (mW/cm2/nm) from a broad-spectrum LED light unit (Bluephase G2, Ivoclar Vivadent) were measured over the luting material (control) and through 0.3 mm, 0.7 mm, and 1.0 mm thick ceramic discs (e.max CAD, Ivoclar Vivadent). The LED light delivered 26.1 J/cm2 to the surface and 6.2 J/cm2 through the 1.0 mm thick ceramic. The distribution of violet and blue light across the light tip of the light-curing unit (LCU) was relatively homogeneous, but there was less violet range. The irradiance and spectral radiant power decreased significantly as the ceramic thicknesses increased (p<0.001). The luting material type had significant effect on KH and E values (p<0.001). The RV had the greatest KH and E values, and VE had the lowest. Ceramic thickness had no significant effect on KH (p=0.213) and E (p=0.130). The KH (p=0.265) and E (p=0.165) were also not influenced by the location where these measurements were made across the specimens. No significant reduction of the DC was observed as the ceramic thickness increased (p=0.311). Increasing the ceramic thickness exponentially reduced the irradiance. This reduction was more pronounced at the shorter wavelengths (violet) of light, with an 82% decrease for 1 mm-thick ceramic. Increasing the ceramic thickness did not affect the DC, irrespective of photoinitiators used in the tested resins. The position of the violet and blue LEDs within the body of the LCU did not influence KH or E in any of the resins tested. The KH and E of VE were significantly lower than the other 3 luting materials tested.

Fracture Load of Molars Restored with Bulk-fill, Flowable Bulk-fill, and Conventional Resin Composite After Simulated Chewing.

This study aimed to compare the fracture toughness of molars with wide mesio-occlusal-distal (MOD) cavities restored with regular and flowable bulk-fill resin composite and a conventional resin composite after 250,000 mechanical cycles of chewing simulation. Thirty-two extracted mandibular third molars were selected and class II MOD cavities involving 2/3 of the intercuspal width and 4 mm depth were prepared. Teeth were divided into four groups based on resin composite type and insertion technique (n=8): (1) CT, unprepared teeth (control); (2) CV, conventional resin composite (Tetric N-Ceram, Ivoclar Vivadent) with incremental technique; (3) R-BF, regular bulk-fill resin composite (Tetric N-Ceram Bulk Fill, Ivoclar Vivadent) with a single increment; and (4) F-BF, flowable bulk-fill resin composite (Tetric N-Flow Bulk Fill, Ivoclar Vivadent) with a single increment, except for a 1-mm-thick layer at the occlusal surface, restored with conventional resin composite (Tetric N-Ceram). All specimens were evaluated to detect the presence and propagation of enamel cracks using a LED transilluminator before and after 250,000 mechanical cycles (SD Mechatronic GmbH). After a chewing simulation, they were subjected to a compressive force in a universal testing machine (DL-2000, EMIC) until fracture. The maximum fracture load of the specimens was measured (N) and the fracture patterns were classified based on the fracture site (above or below the cementoenamel junction [CEJ]). Data were statistically analyzed with one-way ANOVA. All specimens survived after 250,000 mechanical cycles, and no statistically significant differences among groups were observed regarding the fracture toughness (p<0.05). The fracture analysis demonstrated that failures below the CEJ were more common in CV (75%), while CT, R-BF, and F-BF showed this type of failure in 38%, 63%, and 63% of the specimens, respectively. The results of the crack analysis showed that the occurrence of new cracks and crack propagation was also higher in CV (33.3%), followed by R-BF, F-BF, and CT (14%, 14%, and 11% of the specimens, respectively). Teeth restored with regular and flowable bulk-fill composites showed similar fracture toughness after the chewing simulation compared to those restored with the conventional resin composite and unprepared teeth. Furthermore, teeth restored with both regular and flowable bulk-fill composites showed a lower incidence of enamel cracks and fractures below the CEJ compared to those restored with the conventional resin composite.

Effect of different industrialized acid beverages on the surface roughness of flowable composite resins: in vitro study.

Flowable composite resins are materials available for restorations in pediatric dentistry. However, these materials are subject to dangerous effects in the oral environment caused by acids that deteriorate and increase their roughness. Therefore it is important to evaluate the effect of different industrialized acid beverages on the roughness of flowable composite resins. An in vitro experimental study, was done using a convenience sample of 132 discs of 5 mm diameter by 2 mm depth of four flowable materials (FF (Filtek™ Z350 XT Flowable), TNF (Tetric® N-Flow), PF (PermaFlo®) and GF (Grandio® Flow)) exposed to three beverages (CC (Coca-Cola), AJ (apple juice), and FM (fermented milk)) and incubated at 37 ºC for 0, 15 and 30 days. The roughness (average roughness (Ra) and maximum height of profile (Rz) parameters) was measured at different intervals of time with a profilometer. For the data analysis, one-way analysis of variance (one-way ANOVA) and repeated measures analysis of variance (Repeated measures ANOVA) tests were applied (p < 0.05). In the roughness test before immersion, no differences were observed within the groups, with maximum roughness values for Filtek™ Z350 XT Flowable and minimum for PermaFlo®. However, at 15 and 30 days of immersion, the groups showed significant differences depending on the immersion drink, except Grandio® Flow in apple juice and fermented milk. The flowable materials studied presented specific behaviors according to the immersion period and drink used. The Filtek™ Z350 XT Flowable showed a similar increase in surface roughness independently of the drink used. Grandio® Flow was the most stable material against surface roughness changes after beverage immersion.

Physical evaluation of the luting systems for veneer ceramic after aging / Avaliação física dos sistemas de cimentação para faceta cerâmica após envelhecimento

The aim of this in vitro study was evaluated the amount of color change and degree of conversion of the luting systems for ceramic veneer cementation. Forty-eight human incisors were randomly divided into six groups (n=8) according to the bonding procedure: RelyX Veneer/Single Bond 2; RelyX ARC/Single Bond 2; Filtek Z350 XT Flowable /Single Bond 2; Variolink Veneer/Tetric N-Bond; Variolink II/Tetric N-Bond; Tetric N-Flow/Tetric N-Bond. Ceramic veneers (IPS Empress Esthetic) were cemented using the different bonding procedures. Color differences of the ceramic surface after cementation and 300 h(150kJ/m2) of UV aging test, were examined with a colorimeter. Fourier transform infrared spectroscopy (FT-IR) was used to evaluate the degree of conversion for each luting system. Data were analyzed with one-way ANOVA and Tukey's test (α=0.05). All the luting systems demonstrated significant changes in color stability. The ΔE of the systems ranged from 6,11 to 9,33. Tetric N-Flow and RelyX Veneer showed the highest degree of conversion, while lowest values were found for RelyX ARC. All luting systems demonstrated clinically unacceptable (ΔE≥ 3.3) color changes. Despite to the dual cure of the RelyX ARC luting cement, it showed the lowest degree of conversion values, while Tetric N-Flow and RelyX Veneer presented the highest and similar degree of conversion.

Flowable fiber-reinforced versus flowable bulk-fill resin composites: Degree of conversion and microtensile bond strength to dentin in high C-factor cavities.

To compare flowable fiber-reinforced and flowable bulk-fill resin composites regarding their degree of conversion (DC) and microtensile bond strength (μTBS) to dentin in high C-factor class I cavities. One flowable fiber-reinforced (EverX Flow, GC) and two flowable bulk-fill composites (SDR, Dentsply, and Tetric N-flow Bulk fill, Ivoclar Vivadent) were tested. Regarding DC, 10 cylindrical-shaped specimens were prepared from each material (N= 30), measured using Fourier-Transform Infrared Spectroscopy (FTIR). Regarding , class I cavities (4.5× 4.5× 3) were prepared on flat dentin surfaces of 30 molars, divided into three equal groups, restored with the three restorative materials, thermocycled, sectioned to create 1 mm × 1 mm cross-sectional beams, then tested using a universal testing machine. Failure mode was assessed using a stereomicroscope. Two-way ANOVA and Tukey's HSD post-hoc tests were used in DC, while One-way ANOVA was used for . The used materials showed statistically significant differences in DC with the fiber-reinforced composite having the highest value. No statistically significant differences were found between the materials regarding their . Flowable fiber-reinforced composite provided the most DC performance compared to the flowable bulk-fill composites. The three used restorative materials provided comparable bonding ability to dentin in high C-factor cavities. Flowable fiber-reinforced resin composite is preferred as a dentin-replacement material in high-stress bearing areas. However, both flowable fiber-reinforced and bulk-fill resin composites are equally effective in bonding to dentin in high C-factor cavities.

Comparative clinical evaluation of a self-adhering flowable composite with conventional flowable composite in Class I cavity: An in vivo study.

Context:The purpose of this study was to evaluate the efficiency of self-adhering flowable composite with that of a time-tested conventional flowable composite. Since the self-adhering composite reduces chair time and is convenient to use, its clinical behavior was monitored for a year.Aim:This study aimed to evaluate the clinical behavior of self-adhering flowable composite – Fusio Liquid Dentin – in small-sized Class I cavities and also to compare it with conventional flowable composite – Tetric N-Flow – bonded to the tooth structure with fifth-generation two-step-etch-and-rinse adhesive.Subjects and Methods:A total of 60 cavities were restored using flowable composite materials (30 cavities in each group) and evaluated at baseline, 1 month, 3 months, 6 months, and 1 year with modified United States Public Health Service criteria. The statistical analysis for the study was done using Fisher's exact test for intergroup comparison and Chi-square test for intragroup comparison. P < 0.05 was considered statistically significant.Results:Statistically no significant differences were observed in Fusio Liquid Dentin restorations during the recall visits. Statistically significant differences were found in color match evaluated for Tetric restorations during the recall visits.Conclusion:Based on the data acquired, the novel self-adhering composite material demonstrated good clinical behavior. As a result, at this point in the prospective clinical study, the use of Fusio Liquid Dentin to repair Class I cavities is acceptable.

Assessment of the Shear Bond Strength of Composite Resin to Fresh Amalgam Using Different Adhesion Protocols: An In Vitro Study

Introduction: This study was conducted to evaluate and compare the effect of using three adhesive systems on the shear bond strength between composite resin and fresh amalgam. Materials and Methods: Amalgam samples were assigned into three groups according to the adhesive systems being used prior to the composite resin application. Group A (n = 10): universal self-etch bonding system (Single Bond Universal Adhesive, 3M, Neuss, Germany) was applied and light cured. Group B (n = 10): universal self-etch bonding was applied and light cured, followed by a thin layer of nanohybrid flowable composite (Tetric N-Flow, Ivoclar Vivadent, Liechtenstein), then light cured. Group C (n = 10): self-adhesive dual-cure luting resin cement (Calibra Universal, Dentsply Sirona, Charlotte, NC) was applied in equal quantity for each sample over amalgam surface. Composite resin was then applied by plastic instrument in a single increment to the height of the hole (2 mm), then celluloid strip was placed and light cured. After thermocycling, a shear bond test was performed. Results: Resin luting cement interface showed the higher significant bond strength, followed by universal bonding agent − flowable composite interface. The universal bonding interface group yielded the lowest results. Conclusion: The application of self-adhesive dual-cure luting resin cement resulted in significant increase in bond strength between composite resin and fresh amalgam.

Does a Self-adhesive Flowable Resin Composite Perform Similarly to Highly Filled and Conventional Flowable Resin Composites in Occlusal Cavities? A 2-year Follow-up Study.

The aim of this clinical trial was to compare a self-adhesive flowable resin composite, a highly filled flowable resin composite used in combination with a universal adhesive applied in self-etch mode, and a conventional flowable resin composite used in combination with a universal adhesive applied using two different application modes in occlusal cavities. Twenty-eight patients received 114 occlusal restorations. Cavities were divided into four groups: CS: a self-adhering flowable (Constic, DMG); GF: a highly filled flowable (G-ænial Universal Flo, GC) in combination with a universal adhesive applied in self-etch mode (G-Premio Bond, GC); TF-SE: a conventional flowable (Tetric N-Flow, Ivoclar Vivadent) in combination with a universal adhesive (Tetric N-Bond Universal, Ivoclar Vivadent) applied in self-etch mode; TF-ER: a conventional flowable (Tetric N-Flow, Ivoclar Vivadent) in combination with a universal adhesive (Tetric N-Bond Universal, Ivoclar Vivadent) applied in etch&rinse mode. Restorations were scored using modified USPHS criteria. Descriptive statistics were performed using chi-squared tests. At 24-month evaluations, none of the restorations were lost. The CS group showed significantly higher bravo scores for marginal adaptation than did the other experimental groups (p = 0.024). Significant changes were seen for CS and GF regarding marginal adaptation compared to baseline. Although the self-adhering flowable resin composite exhibited inferior marginal adaptation compared to the highly filled flowable and conventional flowable resin composites, the restored teeth demonstrated a clinically acceptable performance after 24 months.

Comparing Bacterial Leakage of Three Intraorifice Barrier Sealing Materials against Enterococcus faecalis and Proteus vulgaris

The purpose of this in vitro study was to evaluate the intraorifice sealing ability of light-cured glass-ionomer cement (LC-GIC), Tetric N-Flow, and ProRoot mineral trioxide aggregate (MTA) against Enterococcus faecalis and Proteus vulgaris. Crowns of the eighty human mandibular teeth were decapitated. Working length determination was performed, after which cleaning and shaping were carried out. A uniform orifice diameter of 1.3 mm, at its widest point, was made. Once instrumentation was completed, the canals were irrigated and then obturated. A heat carrier was used to remove gutta-percha to the depth of 3.5 mm. Samples were then divided into a control group (Group 1) with no barrier, and three groups, namely, Group 2, Group 3, and Group 4, were restored with the LC-GIC, Tetric N-Flow, and ProRoot MTA, respectively. The groups were further subdivided into Subgroup A for checking bacterial leakage against E. faecalis and Subgroup B, against P. vulgaris. All samples were subjected to the bacterial leakage test and observed daily for the appearance of turbidity after which statistical analysis was performed. Group 1 showed leakage in, as early as, 3 days. The longest time for the turbidity to appear was shown by Group 4 with an average of 31 days. The mean number of days for turbidity to appear in Group 2 and Group 3 was 23 and 24 days, respectively. Group 4 showed the best intraorifice sealing ability with a significant difference. The teeth with an intraorifice coronal seal had better protection against microbial leakage. Among all materials used, the ProRoot MTA showed the best intraorifice sealing ability. Use of the ProRoot MTA promises long-term results in the endodontically treated teeth as compared with other materials.

Degree of conversion and water sorption of self-adhesive and conventional flowable composites

Aim: Self-adhesive flowable composite resins have been recently introduced to the market. Degree of conversion (DC) and water sorption (WS) are two important parameters affecting the properties of restorative materials. This study aimed to assess the DC and WS of a self-adhesive flowable composite resin in comparison with two conventional flowable composite resins. Methods: Vertise Flow (VF) self-adhesive and Tetric-N Flow (TF) and Grandio Flow (GF) conventional flowable composites were evaluated in this in vitro, experimental study. The DC (n=3) was determined by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The WS (n=7) was measured after 7 days of immersion in artificial saliva according to ISO 4049 specifications. Data were analyzed by one-way ANOVA and a post-hoc test (p&lt;0.05). Results: VF showed the highest DC percentage (84.3%) followed by GF (72.79%) and TF (68.7%). The latter two had no significant difference (p=0.8). WS was the highest in VF (55.2 μg/mm3), and the two conventional flowable composites had a significant difference in WS (19.5 μg/mm3 in TF and 11 μg/mm3 in GF; p&lt;0.001). Conclusions: Flowable composite resins had significant differences in DC and WS, and VF demonstrated the highest DC and WS.

Comparative Evaluation of Cavosurface Marginal Integrity by Assessing Microleakage Scores of Three Different Composites using a Universal Adhesive in Self Etch and Selective Etch Modes- A Stereomicroscopic Study

Introduction: Composite resins are currently the most popular restorative materials due to their superior esthetics, strong mechanical properties and high resistance to dissolution. However, in spite of the improvements in resin composite formulations over the years, polymerisation shrinkage which necessitates incremental placement techniques still presents clinical challenges. Aim: To compare and evaluate cavosurface marginal integrity in Class I restorations by assessing microleakage scores using Tetric N-Flow Bulk fill, SureFil Bulk fill composites and Filtek Z350 XT and using selective etch and self etch modes of a universal adhesive. Materials and Methods: This in-vitro research study was carried out in the Department of Conservative Dentistry and Endodontics, Bapuji Dental College and Hospital, Davangere, Karnataka, India from April, 2018 to May, 2018. Sixty extracted non-carious, intact human mandibular molar teeth were selected for this study. Standardised Class I cavities of 4 mm depth were prepared by a single operator with a high-speed hand piece using carbide fissure # 245 (SS White Inc) bur under air-water coolant. Samples were randomly divided into two main groups in which Single Bond Universal was used: Group I: Selective Etch Mode (30), Group II: Self Etch Mode (30). These main groups were then divided into 3 subgroups each Subgroup TF: Tetric N- Flow Bulk fill (Ivoclar Vivadent), Subgroup SB: SureFil Bulk fill (Dentsply) and Subgroup FC: Filtek Z350 XT (3M ESPE). All the specimens were then sectioned longitudinally along the mesio-distal direction towards the center of the restoration. Each specimen was viewed under a stereomicroscope and grading was done according to dye penetration at the tooth-restoration interface. Kruskal-Wallis and Mann-Whitney U-test were used to analyse the results. Results: The results showed that there was statistically significant difference in the microleakage scores of Tetric N- Flow Bulk fill, Filtek Z350 XT and SureFil Bulk fill (p&lt;0.001). Group I Subgroup TF yielded lower microleakage score 0.70±0.675 as compared to Group II Subgroup TF which had a higher score 1.60±1.578. This difference was not statistically significant. (p-value=0.266). Group I Subgroup SB yielded lower microleakage score 1.20±0.919 as compared to Group II Subgroup SB which had a higher score 2.10±0.568. This difference was statistically significant. (p-value=0.017). Group I Subgroup FC yielded lower microleakage score 2.50±1.354 as compared to Group II Subgroup FC which had a higher score 3.20±0.789. This difference was not statistically significant (p-value=0.260). Conclusion: Tetric N flow bulk fill flowable composite resin can be considered as a better choice when compared to SureFil bulk fill and Filtek Z350XT composite resins. Selective enamel etching with SureFil bulk fill should be considered as the better choice as compared to self-etch for providing adequate seal in mild universal adhesives in Class I cavities.

Resistência à compressão de compósitos de preenchimento único

A new class of composite resins called single fill resins (Bulk-Fill) was proposed to simplify restorative procedures. They allow filling dental cavities in layers of approximately 4mm. This study aims to compare the compression strength of single fill composites with different polymerization times. Four Bulk-Fill composites were used Filtek Bulk-Fill, Filtek Bulk-Fill Flow, Tetric N-Ceram Bulk-Fill, and Tetric N-Flow Bulk-Fill, and also a conventional composite Filtek Z350 XT as a control group. One hundred cylinders were manufactured in a matrix with 4.7mm diameter and 4mm height for Bulk-Fill compounds, and 2mm height for the control group. Half of the specimens of each material was photopolymerized for 10 seconds and the other half for 20 seconds (n = 10). The samples were stored in distilled water for 48 hours at 37°C and subjected to compression testing in a universal test machine. Variance analysis was performed with t-test of multiple comparisons between groups and student t-test for the different polymerization times with significance index p=0.05. The results did not show statistically significant difference in relation to polymerization time. However, there was a statistically significant difference between the control and Filtek Bulk-Fill Flow groups, which presented higher strenght to compression than the Filltek Bulk-Fill, Tetric N-Ceram Bulk-Fill, and Tetric N-Flow Bulk-Fill groups. The type of resin can influence its resistance to fracture. The polymerization time did not have any influence in the materials strength.

Profundidade de cura das resinas bulk fill variando a fonte de luz

Analisar a profundidade de cura das resinas do tipo Bulk Fill (Fluida e Pasta) alterando a fonte de luz. 10 tipos de resinas foram analizadas: (P) Pasta: FiltekTM One Bulk Fill (F1), Tetric N-Ceram Bulk Fill (T1); Aura Bulk Fill (A1); OPUS Bulk Fill (O1) e (F) Fluida: FiltekTM Bulk Fill Flow (F2); Tetric N-Flow Bulk Fill (T2); SDR® Plus Bulk Fill Flowable (S2); OPUS Bulk Fill Flow (O2). Foram confeccionados três discos para cada grupo seguindo ISO 4049/2000, através de molde (4x10mm), que foi totalmente preenchido com resina e fotoativado num tempo de 20s, sendo variado a fonte de luz entre Gnatus (G) e Kavo (K). Imediatamente depois as amostras foram removidas e a parte não polimerizada foi retirada com espátula de plástico. A mensuração foi realizada com um micrômetro de precisão ± 0,1mm. Os dados foram analisados usando ANOVA One-Way e ANOVA Two-Way e teste-t com significância de 0,05. Os grupos T1-K, S1-K, F1-K, F1-G, F2-G e T1-G mostraram resultados de profundidade de polimerização compatíveis com recomendações de fabricante. As fontes de luz G e K não apresentaram diferença (p = 0,068), mas entre os grupos (O2-G) (O2-K) (p = 0,004) houve diferença. Não foram encontradas diferenças entre as resinas (P-K p = 0,059), mas houve: grupo (F-K p =&lt; 0,050), entre resinas-K (p =&lt; 0,050), entre grupos (P-G) (F-G) e resinas-G (p =&lt; 0,050). Resinas fluidas (S2 e T2) apresentaram resultados de profundidade de cura superior a outras. A composição do material, assim como o comprimento de onda, pode ter influenciado nos resultados.

Evaluation of the Bond Strength and Cytotoxicity of Alkasite Restorative Material

Cention N (CN; Ivoclar Vivadent, Schaan, Liechtenstein), advertised as an alkasite, is a bioactive bulk-fill resin-based composite (BF-RBC) with alkaline fillers. This study evaluated the resin-dentin micro-tensile bond strength (μTBS) and cytotoxicity of CN. Methods: Flat dentin surfaces were obtained, bonded with a universal adhesive, and randomly distributed into two groups. CN (group I) and a flowable BF-RBC, namely, Tetric N-Flow Bulk Fill, Ivoclar Vivadent, Schaan, Liechtenstein (group II), were used. After thermocycling, bonded samples were sectioned into micro-beams for μTBS evaluation. Resin-based composite (RBC) discs with a thickness of 2 and 4 mm were tested on human gingival fibroblast cells (HGFCs). Cytotoxicity was assessed by cell viability and growth using AlamarBlue® (Biosource, Camarillo, CA, USA) over a seven-day period. Independent t-test was utilized to statistically analyze μTBS data, while one- and two-way analysis of variance (ANOVA) and Tukey’s post-hoc tests were utilized to analyze the cell viability data. Results: There was no statistically significant difference (p &gt; 0.05) in the μTBS between the flowable BF-RBC and CN. For both materials, the HGFCs were viable, with constant growing over the seven-day period. Conclusion: CN provided a resin-dentin μTBS that was comparable to that provided by the flowable BF-RBC. Both materials showed acceptable cytotoxicity over the seven-day period at a thickness of both 2 and 4 mm.