Self-adhering Flowable Resin Composite Research Articles

Clinical Evaluation of the Retention of Self-adhering Flowable Composite as Fissure Sealant in 6-9-year-old Children: A Randomized Controlled Trial.

AimTo evaluate the retention rate of self-adhering flowable composite as fissure sealant in comparison with the unfilled resin sealant on first permanent molars of 6–9-year-old children.Materials and methodsA 2-arm, split-mouth randomized controlled trial included 100 children of age 6–9 years with completely erupted mandibular first permanent molars. A total of 200 teeth were randomly divided into two groups, group I: self-adhering flowable composite; group II: unfilled resin sealant. Sealants were placed on the mandibular first permanent molars and the children were recalled at 6, 12, and 18 months intervals to evaluate the retention rate. Chi-square test was used to analyze the data.ResultsSelf-adhering flowable composite has shown a complete retention rate of 67%, 47%, and 46% at 6, 12, and 18-month intervals, respectively, whereas unfilled resin sealant has shown 41%, 8%, and 5% retention rate at 6, 12, and 18-month intervals, respectively. The difference in the complete sealant retention rates between the groups is found to be statistically highly significant at all the follow-up intervals (p = 0.0004, 0.0001, and 0.0001 at 6, 12, and 18-month intervals, respectively). In both groups, maximum sealant loss occurred between 6 and 12-month intervals. Retention rates were higher at 6 months intervals which were significantly reduced over 18 months intervals.ConclusionSelf-adhering flowable composite has shown a higher retention rate compared to unfilled resin sealant at all the time intervals. The retention rate of both materials decreased with time. However, the loss of sealant was more with unfilled resin sealant.Clinical significanceIn pediatric dental practice, the elimination of a step in restorative dentistry protocol makes a big difference as time is a critical factor in obtaining children's cooperation. The use of self-adhering materials eliminates the step of bonding agent application, which simplifies the restorative protocol and makes the clinical practice effective. Therefore, these self-adhering flowable composite resin materials can be considered fissure sealants in routine clinical practice.How to cite this articleBhuvaneswari P, Vinay C, Uloopi KS, et al. Clinical Evaluation of the Retention of Self-adhering Flowable Composite as Fissure Sealant in 6–9-year-old Children: A Randomized Controlled Trial. Int J Clin Pediatr Dent 2022;15(3):322-326.

A Comparative Clinical Study of the Self-Adhering Flowable Composite Resin Vertise Flow and the Traditional Flowable Composite Resin Premise Flowable

Background. The aim of this research was to carry out a comparative clinical study of a self-adhesive, light-curing composite material called Vertise Flow and a traditional flow material called Premise flowable used in combination with dedicated bonding systems. In order to standardize the clinical environment, the stability of oral hygiene (analyzed with the oral hygiene index and the approximal plaque index) was taken into consideration. Methods. The study involved 37 patients with 64 fillings. They were distributed into three groups: 22 fillings in Group I, 22 fillings in Group II and 20 fillings in Group III. In Group I (G I), Vertise Flow material was applied without the use of an etching agent or a bonding system; in Group II (G II), Premise flowable material was applied without the use of an etching agent, but with the use of the OptiBond All-In-One seventh-generation bonding system; in Group III (G III), Premise flowable material was applied after etching and treatment of the hard tooth tissues using a fifth-generation OptiBond Solo Plus bonding system. Then, at appropriate time intervals (0, i.e., right after filling and after 6, 12 and 24 months), the fillings were subjected to clinical evaluation, conducted according to the Ryge scale criteria with the use of registration by means of a fluorescent high-intensity visible light beam produced by a camera (Vista Proof). Results. The quality of fillings performed with the use of comparable materials was subjected to clinical evaluation using the Ryge scale of fillings after 6, 12, and 24 months; the examination showed significant differences between the tested materials. The Vertise Flow material used without an etching agent or a bonding system (G I) presented the weakest results with respect to marginal adaptation and smoothness among those evaluated in this study. The intensification of the degradation continued over time until the final clinical observation at 24 months. The results confirmed that the best quality was achieved with the Premise flowable material after etching and treatment of the hard tooth tissues using a fifth-generation OptiBond Solo Plus bonding system (G III) relative to others for all time points during the observation. Conclusions. The used preparation scheme and bonding system have an impact on the final quality of the composite filling. There is a need to carry out a qualitative clinical evaluation of dental restorative materials under uniform conditions using evaluation scales.

Klinička procjena samoadhezivnih tekućih kompozita u liječenju minimalno invazivnih kaviteta I. razreda: petogodišnji rezultati dvostruko slijepoga randomiziranog kontroliranog kliničkog istraživanja

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.

Evaluation of Shear-Bond-Strength of Dental Self-Adhering Flowable Resin-Composite versus Total-Etch One to Enamel and Dentin Surfaces: An In-Vitro Study.

AIM:This study aimed to assess the shear bond strength of a self-adhering flowable resin composite versus a total-etch one to different surfaces of permanent-molars.MATERIAL AND METHODS:Thirty-six sound human permanent molars were used. The teeth were embedded in acrylic blocks, such that their buccal surfaces were shown. The teeth were divided into three groups: Group I: Uncut-Enamel, Group II: Cut-enamel-surfaces with minimal-grinding and Group III: dentin-surfaces. Half of the teeth in each group were used for bonding to a self-adhering flowable resin-composite (Dyad-flow, Kerr, USA). While the other half of each group was bonded to a total-etch flowable resin-composite (Filtek™Z350-XT,3M-ESPE, USA) which necessitate etching and bonding. Teflon-mold was used for constructing resin composite cylinders (3 × 3 mm) over the buccal surfaces. The Dyad-flow was applied in the central hole of the mould placed upon tooth-surface, and then light-cured for 20 seconds. The Filtek-Z350-XT was applied similarly after etching and bonding steps. The teeth were stored in 37°C distilled water for 24 hours. The strength was measured using a universal testing machine and statistically analysed. Modes of failure were studied using digital-microscope.RESULTS:Mean values of shear bond strength for the Dyad and Filtek-Z350-XT in the uncut-enamel were 3.5 and 24.6MPa respectively, while that for cut-enamel were 4.5 and 12.7MPa respectively (Both highly statistically significant P ≤ 0.01) and in dentin were 4.3 and 6.7MPa respectively (Statistically significant P ≤ 0.05). The failure mode for Dyad was mainly adhesive (un-cut or cut-enamel 83.3% adhesive and 16.7% mixed, while in dentin 100% adhesive). While the modes of failure for Filtek-Z350-XT in enamel, either cut or un-cut, were 50% cohesive and 50% mixed, whereas in dentin 100% adhesive.CONCLUSION:Bonding of self-etch ″Dyad-flow″ flowable resin-composite was lower than the total-etch one in enamel and dentin. Thus further material improvement may be required.

Bonding performance of a self-adhering flowable composite resin to different deciduous surfaces

Objective: Evaluation of the shear bond strength of self-adhering flowable composite-resin to different surfaces of deciduous molars.Methods: Eighteen-freshly extracted sound human deciduous molars were used. The teeth were embedded in acrylic blocks, such that their buccal surfaces were shown and aligned with the acrylic surfaces. The teeth were randomly divided into three groups. Group I: enamel surfaces without any intervention (Uncut Enamel), Group II: enamel surfaces with minimal grinding (Cut Enamel) and Group III: dentin surfaces. For all groups, self-adhering flowable composite-resin (DyadTM-flow, Kerr, USA); was applied. Specially designed holed-split Teflon mould was used for constructing composite - resin cylinders (3×3mm) over the buccal surfaces of the mounted teeth. The DyadTM-flow was applied in a central hole of the mould upon tooth surface, and then light cured for 20 seconds. The teeth were stored in distilled water at 37OC for 24 hours. The strength was recorded blindly by a different assessor using universal testing machine and statistically analyzed. Modes of failure were studied using digital microscope.Results: Mean values of shear bond strength for groups I, II, III were 9.6, 5 and 3.6 MPa respectively, with statistically insignificant difference P=0.09 (P value≥0.05). Some specimens showed spontaneous de-bonding after water storage [group I (33.3%) and III (83.33%)]. Failure mode was 100% adhesive failure in all groups. Conclusions: Bonding of DyadTM-flow was highest in uncut enamel however further material improvement may be required.

Comparison of self-adhering flowable composite microleakage with several types of bonding agent in class V cavity restoration

The aim of the present study was to compare the marginal seal of self-adhering flowable composite resin with three universal bonding systems using the self-etch technique in Cl V cavities at enamel and dentin margins. In this in vitro study, Cl V cavities were prepared on the buccal surfaces of forty premolars, with the occlusal margin of each cavity on enamel and gingival margin on dentin. The teeth were divided into four groups (n = 10) in terms of the adhesive used; Group 1: Vertise Flow (VF) self-adhering composite resin, Group 2: Clearfil S3 Bond Universal (CS3BU), Group 3: G-Premio Bond (GPB), Group 4: Single Bond Universal (SBU). In Groups 2, 3, and 4, Z350 flowable composite resin was used to restore the cavities. After thermocycling, the samples were immersed in 10% methylene blue for 24 h and evaluated under a stereomicroscope after buccolingual sectioning; microleakage at enamel and dentin margins was recorded. Kruskal-Wallis and Mann-Whitney tests were used for statistical analyses. Statistical significance was set at P < 0.5. Vertis Flow self-adhering composite resin exhibited significantly higher microleakage at enamel and dentin margins compared to SBU and CS3BU; however, it had significantly less microleakage at enamel margin compared to GPB (P < 0.05). At the enamel and dentin margins, the minimum microleakage values were recorded at SBU and CS3BU margins, respectively. GPB exhibited the highest microleakage values among the groups evaluated and in all the groups, microleakage at dentin and enamel margins was significantly different (P < 0.05) except for SBU group. The marginal sealing ability of self-adhering flowable composite resin at enamel and dentin margins was poor compared to the majority of bonding agents evaluated.

Efficiency of self-adhering flowable resin composite and different surface treatments in composite repair using a universal adhesive.

The aim of this in vitro investigation was to evaluate the efficiency of self-adhering flowable resin composite (Vertise Flow, Kerr, Orange, CA, USA) and different surface treatments in the repair microtensile bond strength (μTBS) of aged nanofill resin composites using a universal adhesive. Aged substrates (×5000 thermocycling) were prepared using a nanofill (Filtek Ultimate; 3M ESPE) resin composite and randomly assigned to different surface treatments: (1) no treatment (control), (2) acid etching with 37% phosphoric acid, (3) Al2O3sandblasting, and (4) sandblasting with CoJet (3M ESPE). After surface treatment, specimens were further divided into two groups: no universal adhesive application and universal adhesive application. Vertise Flow was added to the substrates at 2-mm layer increments to a height of 5 mm and light cured. Restored specimens were sectioned to obtain 1.0-mm2 beams for μTBS testing. Data were analyzed with two-way analysis of variance and Tukey's honest significant difference tests (P < 0.05). The lowest μTBS values were recorded in the control and acid etching groups with no universal adhesive application (P < 0.05). Universal adhesive application significantly increased the repair μTBS values of all surface treatments (P < 0.05), except CoJet treatment. There were no significant differences between Al2O3sandblasting, CoJet application, and acid etching groups with the universal adhesive application (P > 0.05). Vertise Flow can be used effectively in the repair of old nanofill resin composites. The usage of universal adhesive with prior acid etching to obtain acceptable repair performance would be the practical choice under clinical conditions.

Interfacial microscopic examination and chemical analysis of resin-dentin interface of self-adhering flowable resin composite.

Background: The newly introduced self-adhering flowable resin-composites decrease the required time for application by incorporation of an acidic adhesive monomer, thus reducing the number of steps, but its bonding is still uncertain. The aim of this study was to evaluate the interfacial microscopic examination and chemical analysis at the resin-dentin interface of a self-adhering flowable resin composite (Vertise™Flow Self-Adhering Flowable Composite, Kerr Dental, USA) versus a total-etch (Te-Econom Plus) resin composite, using an etching agent (Eco-Etch gel) and bonding agent (Single Bond Universal). Methods: Sixteen freshly extracted sound human posterior teeth were used. The teeth were randomly divided into two groups: 8 specimens per type of composite. Standard-shaped class V cavities were prepared on the buccal surface. One group was restored by Te-Econom Plus resin composite by total-etch technique using Eco-Etch gel, which was applied to dentine for 15 seconds, followed by rinsing, drying and bonding agent application (Single Bond Universal). The other group restored directly with self-adhering resin composite (Vertise-Flow) without application of etch or bond. Curing was done for 20 seconds using a light emitting diode light curing unit. Evaluation of the resin-dentin interface was done microscopically by examination of marginal gap distance in μm using scanning electron microscope (SEM), and chemical analysis of silver particles was observed using SEM with energy-dispersive X-ray spectrometry after 24 hours of specimen storage in ammoniacal silver nitrate. Results: Regarding marginal gap distance (µm) and silver atomic % mean values, teeth restored with self-adhering resin composite (Vertise-Flow) showed significantly higher mean values than the multi-step etch and rinse resin composite group (5.2 vs 0; 12.2 vs 8.2, respectively). Conclusions: Resin-dentin bonding using total-etch resin composite technique was more effective than self-adhering flowable resin composite (Vertise-Flow) regarding marginal gap formation and penetration of silver particles. Further studies for bond strength could be performed.

Effectiveness of different resin composite materials for repairing noncarious amalgam margin defects.

Objectives:The specific objective of this in vitro study was to determine whether the current flowable resin composites can establish an effective seal in repairing noncarious amalgam margin defects.Material and Methods:A total of 30 freshly extracted caries-free human third molars were used for this investigation. Class I preparations with a standardized 160-μ marginal defect were made by condensing amalgam against a Mylar strip. Accelerated aging and corrosion protocols were then applied to simulate oral conditions. The prepared teeth were randomly divided into five groups (n = 6 per group) according to the repair material employed as follows: (1) no treatment (control); (2) self-adhering flowable resin composite (Vertise Flow); (3) flowable resin composite (Filtek Ultimate Flowable); (4) sonic-activated resin composite (SonicFill); and (5) self-adhesive cement (SmartCem2). Specimens were thermocycled again and then immersed in 5% methylene blue at 37°C for 24 h. For dye-leakage measurements, specimens were sliced longitudinally using a low-speed diamond disk.Results:The results indicated that the flowable resin composite material significantly reduced marginal microleakage compared to the control and SonicFill (P < 0.05).Conclusion:Current flowable resin composites were found to be adequate materials for repairing noncarious amalgam margin defects.

Evaluation of Marginal Adaptation of a Self-Adhering Flowable Composite Resin Liner: A Scanning Electron Microscopic Study.

Background:“Self-adhering composite resins,” are claimed to eliminate the need for a separate acid etching and bonding agent application step, thus simplifying the direct restorative procedure, both regarding the technique sensitivity and the duration of treatment.Aim:The aim of this study is to evaluate the marginal adaptation of self-adhering flowable composite (Dyad flow) in comparison to the conventional flowable composite (Tetric N-flow) under scanning electron microscope (SEM).Settings and Design:This in vitro study was conducted on 44 extracted human maxillary premolars.Materials and Methods:Box-only Class II cavities on the distal surface were prepared with the dimensions of 4 mm buccolingual width, 2 mm mesiodistal depth, and gingival margin at the cementoenamel junction. They were divided into two groups of 22 teeth each and were restored accordingly: Group I – Gingival floor lined with Tetric N-Flow and were restored with Tetric N-Ceram; Group II – Gingival floor lined with Dyad flow and were restored with Herculite Precis. After thermal cycling, the sectioned tooth-restoration interfaces were evaluated for the marginal adaptation under SEM at ×200 magnification.Statistical Analysis Used:The resultant data were statistically analyzed by applying Chi-square test, using the SPSS (version 16.0) software.Results and Conclusion:There was no statistically significant difference between the study groups regarding the marginal adaptation. The marginal adaptation of the self-adhering flowable composite when used as a liner in Class II restorations was comparable to that of the conventional flowable composite.

Bond Strength of Self-Adhering Materials: Effect of Dentin-Desensitizing Treatment with a CPP-ACP Paste.

This study investigated the effect of dentin-desensitizing treatment with a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste on shear bond strength (SBS) of two types of self-adhering (SA) restorative materials: resin-modified glass-ionomer (Fuji II LC, GC) and self-adhering flowable composite resin (Vertise Flow, Kerr). Flat and smear layer-free dentin surfaces from 48 extracted molars were prepared and divided into four groups (n = 12 per group) according to Fuji II LC or Vertise Flow and CPP-ACP pretreatment or not. After SBS testing, data were statistically analyzed. The adhesive interfaces were examined by scanning electron microscopy. SBS was significantly affected by CPP-ACP treatment (P < .001) and SA material (P < .05). The interaction of the two factors was not significant. The results suggested that the CPP-ACP pretreatment of the exposed dentin could have a beneficial effect on bonding ability and interfacial integrity of both SA materials so that intimately adapted interfaces were observed in CPP-ACP groups.

Interfacial microscopic examination and chemical analysis of resin-dentin interface of self-adhering flowable resin composite.

Background: The newly introduced self-adhering flowable resin-composites decrease the required time for application by incorporation of an acidic adhesive monomer, thus reducing the number of steps, but its bonding is still uncertain. The aim of this study was to evaluate the interfacial microscopic examination and chemical analysis at the resin-dentin interface of a self-adhering flowable resin composite (Vertise™Flow Self-Adhering Flowable Composite, Kerr Dental, USA) versus a total-etch (Te-Econom Plus) resin composite, using an etching agent (Eco-Etch gel) and bonding agent (Single Bond Universal). Methods: Sixteen freshly extracted sound human posterior teeth were used. The teeth were randomly divided into two groups: 8 specimens per type of composite. Standard-shaped class V cavities were prepared on the buccal surface. One group was restored by Te-Econom Plus resin composite by total-etch technique using Eco-Etch gel, which was applied to dentine for 15 seconds, followed by rinsing, drying and bonding agent application (Single Bond Universal). The other group restored directly with self-adhering resin composite (Vertise-Flow) without application of etch or bond. Curing was done for 20 seconds using a light emitting diode light curing unit. Evaluation of the resin-dentin interface was done microscopically by examination of marginal gap distance in μm using scanning electron microscope (SEM), and chemical analysis of silver particles was observed using SEM with energy-dispersive X-ray spectrometry after 24 hours of specimen storage in ammoniacal silver nitrate. Results: Regarding marginal gap distance (µm) and silver atomic % mean values, teeth restored with self-adhering resin composite (Vertise-Flow) showed significantly higher mean values than the multi-step etch and rinse resin composite group (5.2 vs 0; 12.2 vs 8.2, respectively). Conclusions: Resin-dentin bonding using total-etch resin composite technique was more effective than self-adhering flowable resin composite (Vertise-Flow) regarding marginal gap formation and penetration of silver particles. Further studies for bond strength could be performed.

Interfacial microscopic examination and chemical analysis of resin-dentin interface of self-adhering flowable resin composite

Background: The newly introduced self-adhering flowable resin-composites decrease the required time for application by incorporation of an acidic adhesive monomer, thus reducing the number of the steps, but its bonding is still uncertain. The aim of this study was to evaluate the interfacial microscopic examination and chemical analysis at the resin-dentin interface of a self-adhering flowable resin composite (Vertise-Flow) versus a total-etch (Te-Econom Plus) resin composite, using an etching agent (Eco-Etch gel) and bonding agent (Single Bond Universal). Methods: Sixteen freshly extracted sound human posterior teeth were used. The teeth were randomly divided into two groups: 8 specimens per type of composite. Standard-shaped class V cavities were prepared on the buccal surface. One group was restored by Te-Econom Plus resin composite by total-etch technique using Eco-Etch gel, which was applied to dentine for 15 seconds, followed by rinsing, drying and bonding agent application (Single Bond Universal). The other group restored directly with self-adhering resin composite (Vertise-Flow) without application of etch or bond. Curing was done for 20 seconds using a light emitting diode light curing unit. Evaluation of the resin-dentin interface was done microscopically by examination of marginal gap distance in μm using scanning electron microscope (SEM), and chemical analysis of silver particles was observed using SEM with energy-dispersive X-ray spectrometry after 24 hours of specimen storage in ammoniacal silver nitrate. Results: Regarding marginal gap distance (µm) and silver atomic % mean values, teeth restored with self-adhering resin composite (Vertise-Flow) showed significantly higher mean values than the multi-step etch and rinse resin composite group (5.2 vs 0; 12.2 vs 8.2, respectively). Conclusions: Resin-dentin bonding using total-etch resin composite technique was more effective than self-adhering flowable resin composite (Vertise-Flow) regarding marginal gap formation and penetration of silver particles. Further studies for bond strength could be performed.

Interfacial microscopic examination and chemical analysis of resin-dentin interface of self-adhering flowable resin composite

Background: The newly introduced self-adhering flowable resin-composites decrease the required time for application by incorporation of an acidic adhesive monomer, thus reducing the number of steps, but its bonding is still uncertain. The aim of this study was to evaluate the interfacial microscopic examination and chemical analysis at the resin-dentin interface of a self-adhering flowable resin composite (Vertise™Flow Self-Adhering Flowable Composite, Kerr Dental, USA) versus a total-etch (Te-Econom Plus) resin composite, using an etching agent (Eco-Etch gel) and bonding agent (Single Bond Universal). Methods: Sixteen freshly extracted sound human posterior teeth were used. The teeth were randomly divided into two groups: 8 specimens per type of composite. Standard-shaped class V cavities were prepared on the buccal surface. One group was restored by Te-Econom Plus resin composite by total-etch technique using Eco-Etch gel, which was applied to dentine for 15 seconds, followed by rinsing, drying and bonding agent application (Single Bond Universal). The other group restored directly with self-adhering resin composite (Vertise-Flow) without application of etch or bond. Curing was done for 20 seconds using a light emitting diode light curing unit. Evaluation of the resin-dentin interface was done microscopically by examination of marginal gap distance in μm using scanning electron microscope (SEM), and chemical analysis of silver particles was observed using SEM with energy-dispersive X-ray spectrometry after 24 hours of specimen storage in ammoniacal silver nitrate. Results: Regarding marginal gap distance (µm) and silver atomic % mean values, teeth restored with self-adhering resin composite (Vertise-Flow) showed significantly higher mean values than the multi-step etch and rinse resin composite group (5.2 vs 0; 12.2 vs 8.2, respectively). Conclusions: Resin-dentin bonding using total-etch resin composite technique was more effective than self-adhering flowable resin composite (Vertise-Flow) regarding marginal gap formation and penetration of silver particles. Further studies for bond strength could be performed.

SHEAR BOND STRENGTH AND INTERFACIAL MICROSCOPIC EXAMINATION OF TWO TYPES OF FLOWABLE RESIN-COMPOSITE TO ENAMEL SURFACE OF DECIDUOUS MOLARS

Aim: Evaluation of shear bond strength of a self-adhering flowable resin-composite versus total-etch one to enamel surface of deciduous molars. Interfaces between these restorations and primary enamel were also microscopically investigated. Materials and Methods: Twenty freshly extracted human deciduous molars were used. For the shear bond strength, twelve molars were embedded in acrylic blocks, such that their buccal surfaces were aligned with the acrylic. The enamel surfaces were subjected to minimal grinding. The teeth were randomly divided into two groups, Group I: Self-adhering flowable resin-composite (Dyad™-flow, Kerr, USA); Group II: Total-etch flowable resin-composite necessitate etching and bonding (Filtek™Z350-XT, 3M-ESPE, USA). A specially designed holed-split Teflon mold was used for constructing resin-composite cylinders (3x3mm) over the buccal surfaces of the mounted teeth. For group I, resin-composite was applied directly on teeth surfaces using the mold and light-cured for 20seconds. For group II, using the mold the following steps were performed: acid etching (15 seconds), 2) bonding agent (light-curing 20 seconds) and 3) resin-composite (light-curing 20 seconds). The teeth were stored in 37°C distillate water for 24 hours. The shear bond strength was recorded and statistically analyzed. Modes of failure were studied using digital microscope. For interfacial examination, cavities (class V) were prepared in buccal surface of eight teeth, filled by the two flowable composites as previous (n=4/group) and scanned using scanning electron microscope. For each group, two teeth were examined from buccal aspect, while the other two were sectioned and inspected.Results: Mean bond strength values for groups I and II were 5 and 21.6 MPa respectively with highly significant difference P=0.005 (P value ≤ 0.01). Modes of failure for groups I and II were [100%adhesive] and [16.7%cohesive within tooth + 83.33%mixed] respectively. SEM micrographs of group I revealed a gap at enamel-restoration interface, while group II showed cohesive failure within enamel at the margins. Conclusions: The bonding performance of the self-adhering resin-composite “Dyad™-flow” still needs further enhancement. Modifications may be required to prevent marginal enamel cracks with the use of Total-etch “Filtek™Z350-XT” flowable resin-composite.

Interfacial microscopic examination and chemical analysis of resin-dentin interface of self-adhering flowable resin composite

Background: The newly introduced self-adhering flowable resin-composites decrease the required time for application by incorporation of an acidic adhesive monomer, thus reducing the number of the steps, but its bonding is still uncertain. The aim of this study was to evaluate the interfacial microscopic examination and chemical analysis at the resin-dentin interface of a self-adhering flowable resin composite (Vertise-Flow) versus a total-etch (Te-Econom Plus) resin composite, using an etching agent (Eco-Etch gel) and bonding agent (Single Bond Universal). Methods: Sixteen freshly extracted sound human posterior teeth were used. The teeth were randomly divided into two groups: 8 specimens per type of composite. Standard-shaped class V cavities were prepared on the buccal surface. One group was restored by Te-Econom Plus resin composite by total-etch technique using Eco-Etch gel, which was applied to dentine for 15 seconds, followed by rinsing, drying and bonding agent application (Single Bond Universal). The other group restored directly with self-adhering resin composite (Vertise-Flow) without application of etch or bond. Curing was done for 20 seconds using a light emitting diode light curing unit. Evaluation of the resin-dentin interface was done microscopically by examination of marginal gap distance in μm using scanning electron microscope (SEM), and chemical analysis of silver particles was observed using SEM with energy-dispersive X-ray spectrometry after 24 hours of specimen storage in ammoniacal silver nitrate. Results: Regarding marginal gap distance (µm) and silver atomic % mean values, teeth restored with self-adhering resin composite (Vertise-Flow) showed significantly higher mean values than the multi-step etch and rinse resin composite group (5.2 vs 0; 12.2 vs 8.2, respectively). Conclusions: Resin-dentin bonding using total-etch resin composite technique was more effective than self-adhering flowable resin composite (Vertise-Flow) regarding marginal gap formation and penetration of silver particles. Further studies for bond strength could be performed.

Marginal integrity of self-adhering flowable composites used as liner under class II restorations: a comparative in vitro micro-CT study

This in vitro study aimed to evaluate the internal adaptation of two different self-adhering flowable composite resin materials used as liners under Class II restorations using microcomputed tomography (micro-CT) analysis. Standard box-only cavities were prepared in 30 extracted human third molar teeth. The cervical floor of the proximal box was 1 mm below the cementoenamel junction. After the preparations were completed, the teeth were randomly and equally divided into three groups based on the type of liner used: group 1, universal flowable composite (control; CO); group 2, self-adhering flowable composite (Fusio Liquid Dentin; FU); and group 3, self-adhering flowable composite (Vertise Flow; VE). After lining, the cavities were restored using 2-mm increments of the nanohybrid composite. After storing the specimens for 24 h in distilled water at 37 °C, all teeth were subjected to 5000 thermal cycles of 5/55 °C. Subsequently, the teeth were immersed in a 50% silver nitrate dye at 23 °C for 4 h. Following the immersion, high-resolution micro-CT images were obtained. Silver nitrate penetration into the microgap between the tooth and restoration was calculated for each specimen as a percentage of the entire length of the pulpal floor using image analysis software. One-way analysis of variance was performed to compare the differences among the groups (p = 0.05). No significant differences were observed between the control and self-adhering composite groups (FU, VE; p > 0.05). The performance of self-adhering composites was similar to that of universal flowable composites in terms of marginal microleakage.

Shear Bond Strength of Self-Adhering Flowable Composite and Resin-modified Glass Ionomer to Two Pulp Capping Materials.

Introduction:The aim of this study was to compare the shear bond strength of a self-adhering flowable composite (SAFC) and resin-modified glass ionomer (RMGI) to mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement. Methods and Materials:A total of 72 acrylic blocks with a central hole (4 mm in diameter and 2 mm in depth) were prepared. The holes were filled with MTA (sub group A) and CEM cement. The specimens of both restorative materials were divided into 6 groups; overall there were 12 groups. In groups 1 and 4, SAFC was used without bonding while in groups 2 and 5 SAFC was used with bonding agent. In all these groups the material was placed into the plastic mold and light cured. In groups 3 and 6, after surface conditioning with poly acrylic acid and rinsing, RMGI was placed into the mold and photo polymerized. After 24 h, the shear bond strength values were measured and fracture patterns were examined by a stereomicroscope. Data were analyzed using the two-way ANOVA and student’s t-test.Results:The use of bonding agent significantly increased the shear bond strength of FC to MTA and CEM cement (P=0.008 and 0.00, respectively). In both materials, RMGI had the lowest shear bond strength values (2.25 Mpa in MTA and 1.32 Mpa in CEM). The mean shear bond strength were significantly higher in MTA specimen than CEM cement (P=0.003). There was a significant differences between fracture patterns among groups (P=0.001). Most failures were adhesive/mix in MTA specimen but in CEM cement groups the cohesive failures were observed in most of the samples. Conclusion:The bond strength of self-adhering flowable composite resin to MTA and CEM cement was higher than RMGI which was improved after the additional application of adhesive.

Stability of initiation systems in acidic photopolymerizable dental material

ObjectivesThis study simulated the shelf life to evaluate the stability of initiation systems on acidic photopolymerizable dental material, through an experimental self-adhering flowable composite resin (SACR). MethodsAn SACR model was formulated with monomers Bis-GMA, TEGDMA, acidic monomer (GDMA-P), and inorganic fillers. Initiation system combinations of camphorquinone (CQ), tertiary amine (EDAB), diphenyl phosphine oxide (TPO), phenylbis phosphine oxide (BAPO), and the diphenyliodonium hexafluorophosphate (DPIHFP) were tested. Five SACRs were evaluated, varying the initiation system: SACRCQ, SACRCQ+EDAB, SACRCQ+EDAB+DPIHFP, SACRBAPO and SACRTPO. The SARC were stored at 23°C and, according to shelf life, were evaluated for degree of conversion (DC), polymerization rate (Rp) and microtensile bond strength (μTBS). The DC was evaluated after 0, 1, 2, 4, 8, 12, 24 and 48 storage weeks of SACRs. Bonding to dentin was performed after 0, 4, 8, 12 and 24 storage weeks of SACRs and tested immediately (24h) and after 6 and 12 months by μTBS. Halogen light curing unit (3M ESPE) was used for photoactivation procedures. ResultsSACRCQ+EDAB+DPIHFP showed higher Rp. The DC of SACRCQ+EDAB, SACRCQ+EDAB+DPIHFP, and SACRBAPO were similar (40%) and higher than SACRTPO and SACRCQ (20 and 10%, respectively), staying stable up to 48 weeks. The SACRCQ, SACRCQ+EDAB, and SACRTPO had pre-testing failure on μTBS. The shelf life of SACRs did not affect the μTBS of the groups that obtained adhesion. Furthermore, the immediate μTBS (MPa) SACRCQ+EDAB+DPIHFP (8.4) was similar to SACRBAPO (10.5); however, after 12 months, only SACRCQ+EDAB+DPIHFP maintained the μTBS. SignificanceThe choice of a suitable initiation system is crucial to the performance and stability of acidic photopolymerizable dental material.

Effect of laser preparation on adhesion of a self-adhesive flowable composite resin to primary teeth.

The aim of the study was to evaluate the adhesion of a self-adhering flowable composite resin to primary tooth enamel and dentin after silicon carbide paper (SiC) and laser pretreatment. Adhesive properties were evaluated as shear bond strength (SBS) and scanning electron microscopic (SEM) characteristics. A total 120 primary canine teeth were randomly divided into two groups to study enamel and dentin. Each group was divided into 6 subgroups (n = 10) according to type of surface preparation (SiC or Er:YAG laser) of enamel or dentin. Three methods were used to build cylinders of restoration on tooth surface: OptiBond All-In-One + Premise Flowable composite, OptiBond All-In-One + Vertise Flow and Vertise flow. After restoration, samples were tested for SBS and failure mode. Twenty eight samples were examined by SEM. The results of the study showed SBS of Vertise Flow was lower than others in enamel and dentin samples pretreated with SiC and in dentin samples pretreated with laser (P < 0.001). Compared to SiC pretreatment, laser pretreatment led to a significantly higher SBS with Vertise Flow on enamel (P < 0.001). Vertise Flow associated with the adhesive led to a higher SBS in enamel and dentin compared to Vertise Flow alone. Adhesive and mixed failure modes were observed more frequently in Vertise Flow groups. SEM images showed that Vertise Flow led to more irregularities on enamel and more open dentinal tubules after laser ablation compared SiC pretreatment.