Conventional Flowable Resin Research Articles

Assessment of Surface Roughness, Color, and Bonding Efficacy: Self-Adhesive vs. Conventional Flowable Resin.

This in vitro study aimed to analyze the surface roughness (Ra) and color stability (ΔEab, ΔE00) following simulated mechanical brushing and to evaluate the microtensile (μTBS) of self-adhering resin flowable (SARF) to dentin. The selected materials were Constic, Yflow AS, and Tetric N flow (TNF/control). Thirty composite resin cylinders were fabricated for surface property evaluation. Ra and color were assessed both before and after simulated brushing. The thresholds of 50:50% perceptibility and acceptability of color differences in the evaluated resins were assessed. For μTBS analysis, fifteen molars were selected, sectioned to expose flat dentin surfaces, and restored according to the manufacturers' instructions for microtensile testing. There were statistically significant differences in Ra among the groups, with Constic exhibiting the highest Ra value (0.702 µm; p < 0.05), whereas Yflow AS presented the lowest Ra value (0.184 µm). No statistically significant difference in color was observed among the groups (p > 0.05). The 50:50% perceptibility and acceptability thresholds were set at 1.2 and 2.7 for ΔEab and 0.8 and 1.8 for ΔE 00. All the results fell within the acceptable limits. The mean μTBS values of Constic, Yflow AS, and TNF were 10.649 MPa, 8.170 MPa, and 33.669 MPa, respectively. This study revealed increased Ra and comparable color stability among all the tested composite resins after abrasion. However, the SARF exhibited lower μTBS compared to conventional using an adhesive system.

Evaluation of the mechanical behavior of bulk-fill and conventional flowable resin composites using dynamic micro-indentation.

The purpose of this research was to investigate the mechanical behavior of commercially available bulk-fill and conventional flowable resin composites using the dynamic micro-indentation method. The effect of inorganic filler content on mechanical properties was also assessed. Weight percentages of the inorganic filler in the resin composite were measured using the ashing technique. The results showed that dynamic hardness and elastic modulus tended to increase with inorganic filler content. Furthermore, the differences in mechanical properties between top and bottom surfaces were less pronounced in bulk-fill flowable resin composites compared with conventional flowable resin composites. In conclusion, the mechanical properties of bulk-fill flowable resin composites are affected by filler content. Moreover, bulk-fill flowable resin composites have a higher polymerization depth than conventional flowable resin composites when sample thickness is 4 mm.

Spectrophotometric Analysis of Different Flowable Restorative Materials

To compare the color change of three flowable composites after exposure to staining solutions. A total of 240 oval samples were constructed of conventional flowable resin composite, self-adhesive flowable resin composite, and nanohybrid flowable ormocer (n = 80). Each set was further subcategorized into three subsets as regards staining solution. The baseline color parameters were recorded using spectrophotometer after the immersion of the specimens in artificial saliva for 24 hours. Then, the measurements were taken again after exposure to staining solutions where the color change was measured as ΔE* = V (ΔL*2 + Δa*2 + Δb*2). Conventional flowable resin composite had the best color stability in all staining solutions. The coffee was concluded to be the most staining solution. Compared to beverages, mouthwashes had a greater discoloration effect on nanohybrid flowable ormocer than on selfadhesive flowable composite. Conventional flowable composite had the highest color stability among the tested materials, followed by flowable nanohybrid ormocer, and the least was self-adhering flowable composite. Coffee had the greatest discoloration effect, followed by a sports drink and then the energy drink. However, mouthwashes did not have a significant discoloration effect. Selection of flowable composite materials that are resistant to staining by coffee, beverages, or mouthwashes is an important factor that may influence the sustainability of the esthetic quality of the restoration.

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.

Bond strength of self-adhesive flowable resin composites to tooth structure

Aim: To review the current literature regarding the bond strength of self-adhesive flowable resin composites (SAFRCs) to tooth structure, comparing the outcomes with conventional flowable resin composites (CFRCs). Methods: PubMed/Medline, EbscoHost and Scopus databases were screened (last update on November 2020) using related Medical Subject Headings (MeSH) and free terms. We included in vitro studies published in English language comparing the bond strength of SAFRCs and CFRCs to enamel and/or dentin from primary and/or permanent teeth. Results: In total, 23 articles were included. Unlike CFRCs, SAFRCs such as Vertise® Flow and Fusio™ Liquid Dentin exhibited statistically lower bond strength to enamel and dentin from permanent teeth. There were limited studies comparing the enamel bond strength of CFRCs and SAFRCs (prior phosphoric acid etching and/or adhesive system use). Also, we found few studies that evaluated the bonding effectiveness of Constic® and other SAFRCs to primary teeth. Conclusions: Current SAFRCs showed low bond strength to permanent teeth, which impedes to recommend them as a reliable alternative to CFRCs. The bonding performance of Constic® on both hard dental tissues should be evaluated on future studies. Also, more evidence assessing the bond strength of SAFRCs to primary teeth and etched enamel is needed.

Comparative Analysis of the Shear Bond Strength of Flowable Self-Adhering Resin-Composites Adhesive to Dentine with a Conventional Adhesive

This study aimed to measure and compare the Shear Bond Strength (SBS) of a self-adhering flowable resin composite to dentin with a conventional flowable composite, and evaluate the various modes of failure. Thirty (n=30) human premolar teeth were randomly allocated to two groups (Group I: Vertise Flow; Group II: Filtek Ultimate) of 15 specimens each, and SBS was measured for specimens from each group by applying shear load using a Universal Testing Machine (UTM). Modes of failure were observed with an optical microscope. An independent samples T test was performed to test the Levene’s assumption of homogeneity of variance across both groups, with the critical value set at 0.05. The results revealed, that the self-adhering flowable composite (Group I: VertiseTM Flow) resulted in lower shear bond strength as compared with the conventional flowable resin composite (Group II: Filtek Ultimate). Moreover, group I predominantly exhibited non-cohesive failure which reflects a poor bonding to dentin. On the other hand, Group II showed mixed failure for most of the samples, which demonstrate strong adhesive bonding. Therefore, it could be concluded that the self-adhering flowable resin composite (Group I) results in lower SBS to dentin as compare with conventional flowable composite.

Simulated Cuspal Deflection and Flexural Properties of Bulk-Fill and Conventional Flowable Resin Composites.

Some bulk-fill flowable resin composites produce less cuspal deflection than a conventional incrementally filled flowable resin composites. Objective: This study investigated simulated cuspal deflection and flexural properties of bulk-fill and conventional flowable resin composites.Methods and Materials: Five bulk-fill and six conventional flowable resin composites were evaluated. Aluminium blocks with a mesio-occlusal-distal cavity were prepared and randomly divided into groups for each of the different measurement techniques and were further subdivided according to the type of flowable resin composite. The simulated cuspal deflection caused by the polymerization of resin composite within an aluminium block was measured using a highly accurate submicron digimatic micrometer or a confocal laser scanning microscope (CLSM). In addition, the flexural properties of tested resin composites were measured to investigate the relation between cuspal deflection and flexural properties, and the resin composites were observed using scanning electron microscopy.Results: Simulated cuspal deflection of some bulk-fill flowable resin composites was found to be significantly lower than or similar to those for conventional counterparts, regardless of the measurement method. There were statistically significant differences in flexural properties depending on the material, regardless of the type of flowable resin composite. Pearson correlation analysis did not reveal a statistically significant relationship between flexural properties and cuspal deflection.Conclusion: These results indicate that some bulk-fill flowable resin composites exhibit lower cuspal deflection with the bulk-filling technique than is shown by conventional flowable resin composites using the incremental filling technique. Simulated cuspal deflection can be measured using either a micrometer or CLSM, but this experiment failed to show a significant relationship between cuspal deflection and flexural properties of flowable resin composites.

Clinical Evaluation of a Self-Adhering Flowable Resin Composite in Minimally Invasive Class I Cavities: 5-year Results of a Double Blind Randomized, Controlled Clinical Trial.

ObjectiveThe aim of this study was to evaluate the long-term clinical performance of a self-adhering flowable resin composite compared to a conventional flowable resin composite used with an etch&rinse adhesive system in minimally invasive Class I cavities.Materials and MethodsTwenty-five patients received at least one pair of Class I restorations (n=65). After class I cavities had been prepared, they were randomly restored either with a self-adhering flowable resin composite (VertiseFlow/Kerr-VR) [Group-1 (n=33)], or with a flowable resin composite (Luxaflow/DMG-LX) in combination with an etch&rinse adhesive (Teco/DMG) [Group-2 (n=32)] according to the manufacturers' instructions. The restorations were evaluated at baseline and yearly during 5 years according to the FDI criteria by two evaluators. A statistical analysis was carried out using the Pearson Chi-Square test and the Cochran Q-test followed by the Mc Nemar's test (p=0.05).ResultsAfter 5 years a total of 47 restorations were evaluated with a recall rate of 68%. At 4-year, 3 (11.5%) VR and 2 LX (7.6%) restorations exhibited a cumulative retention loss. Seventeen (73.9%) VR and 14 LX (58.3%) restorations exhibited clinically acceptable (2) scores for marginal adaptation. At 5-year evaluations VR and LX showed similar results regarding all evaluated criteria (p > 0.05). The cumulative retention loss rates of VR and LX were 15.3% and 7.6%, respectively. None of the restorations demonstrated a recurrence of caries and post operative sensitivity. Both materials showed significant changes at 4 and 5 years regarding marginal staining when compared to baseline (p<0.001). Furthermore, significant changes were observed for VR and LX at 1, 2, 3, 4 and 5 years for marginal adaptation according to baseline (p<0.001).ConclusionThe use of both materials for the restoration of Class-I cavities demonstrated clinically acceptable performance at the end of 5-year. The self-adhering flowable composite exhibited a clinical performance similar to the conventional flowable applied with an etch&rinse adhesive.

Use of new scratch test and tensile test for evaluation of bond strength of selfadhesive flowable resin composite for repair of artificial tooth erosion

The purpose of this study was to use a new scratch test and tensile test to evaluate the bond strength between artificial erosive enamel or dentin and self-adhesive resin composites as a coating material. Coronal enamel or dentin surface was exposed to an erosive cycle (artificial saliva [AS], pH:7.0 for 6.5 h and acidic carbonated beverages for 5 min, alternated 3 times per day) for the eroded-surface or stored in AS for the remineralized-surface. Two self-adhesive flowable resin composites, Fusio and LLB-CR6 (prototype), and a conventional flowable resin composite, BEAUTIFIL FLOW with self-etching primer system, Clearfil Mega Bond, were applied to enamel or dentin surfaces; and then the bond strengths were measured. For the eroded-surface, there were no significant differences in bonding strength among all materials, as assessed by the new scratch test. Thus, these self-adhesive flowable resin composites might be useful for coating materials on acid-eroded tooth surfaces.

Comparison of traditional and simplified methods for repairing CAD/CAM feldspathic ceramics.

PURPOSETo evaluate the adhesion to CAD/CAM feldspathic blocks by failure analysis and shear bond strength test (SBSt) of different restorative systems and different surface treatments, for purpose of moderate chipping repair.MATERIALS AND METHODSA self-adhering flowable composite (Vertise Flow, Kerr) containing bi-functional phosphate monomers and a conventional flowable resin composite (Premise Flow, Kerr) applied with and without adhesive system (Optibond Solo Plus, Kerr) were combined with three different surface treatments (Hydrofluoric Acid Etching, Sandblasting, combination of both) for repairing feldspathic ceramics. Two commercial systems for ceramic repairing were tested as controls (Porcelain Repair Kit, Ultradent, and CoJet System, 3M). SBSt was performed and failure mode was evaluated using a digital microscope. A One-Way ANOVA (Tukey test for post hoc) was applied to the SBSt data and the Fisher's Exact Test was applied to the failure analysis data.RESULTSThe use of resin systems containing bi-functional phosphate monomers combined with hydrofluoric acid etching of the ceramic surface gave the highest values in terms of bond strength and of more favorable failure modalities.CONCLUSIONThe simplified repairing method based on self-adhering flowable resin combined with the use of hydrofluoric acid etching showed high bond strength values and a favorable failure mode. Repairing of ceramic chipping with a self-adhering flowable resin associated with hydrofluoric acid etching showed high bond strength with a less time consuming and technique-sensitive procedure compared to standard procedure.

Characteristics of low polymerization shrinkage flowable resin composites in newly-developed cavity base materials for bulk filling technique.

The purpose of this study was to evaluate polymerization shrinkage and other physical properties of newly-developed cavity base materials for bulk filling technique, with the brand name BULK BASE (BBS). Polymerization shrinkage was measured according to ISO/FDIS 17304. BBS showed the significantly lowest polymerization shrinkage and significantly higher depth of cure than conventional flowable resin composites (p<0.05). The Knoop hardness, flexural strength and elastic modulus of that were significantly lower than conventional flowable resin composites (p<0.05). BBS had the significantly greatest filler content (p<0.05). SEM images of the surface showed failure of fillers. The lowest polymerization shrinkage was due to the incorporation of a new type of low shrinkage monomer, which has urethane moieties. There were no clear correlations between inorganic filler contents and polymerization shrinkage, flexural strength and elastic modulus. In conclusion, the low polymerization shrinkage of BBS will be useful for cavity treatment in dental clinics.

Pediatric patients tolerance: a comparative study about using of Er:YAG laser and self-adhesive flowable composite for treatment of primary decayed teeth.

To verify the tolerance of children aged between 3 and 8 years, having class I caries and treated with Er:YAG Laser in association with a new self-adhesive flowable resin in comparison with a high-speed diamond bur and a conventional flowable resin treatment. A group of 80 healthy children (43 male and 37 female) ranging in age from 3 to 8 years, who had been diagnosed with at least one active occlusal non-cavitated superficial carious lesions in first or second deciduous molars, were selected for the present study. They were divided in 4 groups: group A: Class I occlusal cavities prepared using an Er:YAG laser and a self-adhesive flowable resin; Group B: Class I occlusal cavities prepared using an Er:YAG laser and a conventional flowable resin; Group C: Class I occlusal cavities prepared using a high-speed diamond bur and a self-adhesive flowable resin; Group D: Class I occlusal cavities prepared using a high-speed diamond bur and a conventional flowable resin. Before and after the treatments the patient tolerance was tested with the modified Wong-Baker pain level scale. In the first group, the tolerance rate was 95% with 0 score (no hurt) for 19 patients; in Group D, the tolerance rate was 75%. Just one child of group D experienced hurting worst because of non cooperative patient. From these results it emerged that, although the limits of the study, Er:Yag laser in association with self-adhering composite, is very effective in pediatric dentistry and is a good treatment option especially for non cooperative patients.

Monomer conversion and shrinkage force kinetics of low-viscosity bulk-fill resin composites

Objective. To investigate the subsurface degree of conversion (DC) and shrinkage force formation of low-viscosity (flowable) bulk-fill composite materials. Materials and methods. Three flowable bulk-fill resin composites [SureFil SDR flow (SDR; Dentsply DeTrey), Venus Bulk Fill (VB; Heraeus Kulzer) and x-tra base (XB; VOCO)] and one conventional flowable control composite material [EsthetX flow (EX; Dentsply DeTrey)] were tested. The materials were photoactivated for 20 s at an irradiance of 1170 mW/cm2 and the DC (n = 5) was recorded at 0.1-, 1.5- and 4-mm depth using Fourier transform infrared spectroscopy. Shrinkage forces (n = 5) of 1.5-mm-thick specimens were continuously recorded for 15 min using a custom-made stress analyzer. Data were statistically analyzed by ANOVA, Tukey’s HSD and Bonferroni’s post-hoc tests (α = 0.05). Results. SDR generated the significantly lowest shrinkage forces (22.9 ± 1.4 N), but also attained the significantly lowest DC at 1.5-mm depth (67.5 ± 0.8%). The conventional flowable composite EX generated the significantly highest shrinkage forces (40.7 ± 0.7 N) and reached a significantly higher DC (74.4 ± 1.3%) compared to SDR and XB at 1.5-mm depth. The shrinkage force values of VB (29.4 ± 1.1 N) and XB (28.3 ± 0.6 N) were similar (p > 0.05). All materials attained significantly higher DC at 4-mm depth than at the near-surface. Conclusion. The tested low-viscosity bulk-fill materials show lower shrinkage force formation than a conventional flowable resin composite at high levels of degree of conversion up to 4-mm incremental thickness.

Shear Bond Strength of Self-Adhering Flowable Composite on Dentin with and without Application of an Adhesive System

The aim of this study was to evaluate the shear bond strength (SBS) of conventional and self-adhering flowable resin composites on the dentin surfaces of primary and permanent teeth and to evaluate the effect of the application of an adhesive system under self-adhering flowable resin composite on SBS. Prepared permanent and primary tooth dentin surfaces were randomly distributed into 3 groups according to application protocols as follows: group 1: Vertise Flow; group 2: OptiBond + Filtek Ultimate; and group 3: OptiBond + Vertise Flow. A universal testing machine was used to measure SBS of prepared specimens, and data were analyzed using 1-way ANOVA and Tukey test. Statistically significant differences were observed among all groups for primary and permanent teeth (P<0.05). The highest values were observed in group 2, followed by group 3, in both permanent and primary teeth. SBSs of all groups were significantly higher for permanent teeth than for primary teeth (P<0.05). Although SBS values of Vertise Flow groups were lower than those for conventional flowable resin composite groups, with further developments in material technology, self-adhering materials could be promising materials especially for pediatric dentistry.

Effect of laser preparation on bond strength of a self-adhesive flowable resin

The aim of this in vitro study was to evaluate the effect of laser treatment on shear bond strength of a self-adhesive flowable resin composite to human dentin. Eighty extracted sound human molar teeth were used for the study. The teeth were sectioned mesiodistally and embedded in acrylic blocks. The dentin surfaces were ground wet with 600-grit silicon carbide (SiC) paper. They were randomly divided into two preparation groups: laser (Er:YAG laser, with 12 Hz, 350 mJ energy) and control (SiC). Each group was then divided into two subgroups according to the flowable resin composite type (n = 20). A self-adhesive flowable (Vertise Flow) and a conventional flowable resin (Premise Flow) were used. Flowable resin composites were applied according to the manufacturer's recommendations using the Ultradent shear bond Teflon mold system. The bonded specimens were stored in water at 37 °C for 24 h. Shear bond strength was tested at 1 mm/min. The data were logarithmically transformed and analyzed using two-way analysis of variance and Student-Newman-Keul's test at a significance level of 0.05. The self-adhesive flowable resin showed significantly higher bond strength values to laser-prepared surfaces than to SiC-prepared surfaces (p < 0.001). The conventional flowable resin did not show such differences (p = 0.224). While there was a significant difference between the two flowable resin composites in SiC-prepared surfaces (p < 0.001), no significant difference was detected in laser-prepared surfaces (p = 0.053). The bond strength of a self-adhesive flowable resin composite differs according to the type of dentin surface preparation. Laser treatment increased the dentin bonding values of the self-adhesive flowable resin.