Vertise Flow Research Articles

Interfacial fracture toughness of aged adhesive–dentin interfaces

ObjectiveTo assess interfacial fracture toughness of different adhesive approaches and compare to a standard micro-tensile bond-strength (μTBS) test after 6 months water storage. MethodsChevron-notched beam fracture toughness (CNB) was determined using a modified ISO 24370:2005 standard. Adhesive–dentin micro-specimens (1.0mm×1.0mm×8–10mm) were stressed in tensile until failure to determine the micro-tensile bond strength (μTBS). ResultsThe highest mean μTBS and interfacial fracture toughness were measured for the multi-step adhesives Clearfil SE Bond (Kuraray Noritake) and OptiBond FL (Kerr). While large differences were observed in the bond strength values (from 7.4 to 27.2MPa) of the one-step self-etch adhesives tested, interfacial fracture toughness was less different (from 0.7 to 1.0MPam1/2). The adhesive with the lowest mean toughness (All-bond Universal, Bisco) had however the highest Weibull reliability, which might be a better parameter in regard to more consistent clinical performance. The self-adhesive composite Vertise Flow (Kerr) scored significantly lower at all levels. SignificanceAlthough the ranking of the adhesives tested using CNB and μTBS corresponded well, the outcome of CNB appeared more reliable and less variable.

Evaluation of bond strength of splinting materials to the teeth using three adhesive systems-an in vitro study

Aim: To evaluate the bond strength of two splinting materials (orthodontic wire and ribbond) to the tooth structure using cyanoacrylate (CA) ester, self-adhering flowable composite (Vertise flow) and conventional flowable composite as adhesives. Materials and Methods: A total of 120 human central incisors free of any carious lesions were selected for the study. To obtain the specimens, 120 human central incisors were embedded in the blocks of rapid polymerizing self-cure acrylic resin with two teeth each. The specimens were divided into six groups with ten specimens each. Group I-Orthodontic wire bonded with CA, Group II-Orthodontic wire bonded with flowable composite Group III-Orthodontic wire bonded with Vertise flow, Group IV-Ribbond bonded with CA, Group V-Ribbond bonded with flowable composite and Group VI-Ribbond bonded with Vertise flow. The adhesive force in newtons to debond the splinting material was measured in tension using universal testing machine. The force at which the splint system failed was noted. The data obtained were statistically analyzed using one-way ANOVA and significant differences were subjected to Tukey's post-hoc test at a confidence interval of 0.05. Results: Bond strength with the orthodontic wire groups was significantly less compared with Ribbond groups p Conclusion: Orthodontic wire groups demonstrated significantly lower bond strength compared to ribbond groups. Among the adhesives CAs showed significantly lower bond strength compared to Vertise flow and conventional flowable composite.

Bonding performance of two newly developed self-adhering materials between zirconium and dentin.

This study evaluated the effect of four resin materials on the shear bond strength (SBS) of a ceramic core material to dentin. Sixty molar teeth were embedded in a self-curing acrylic resin. All specimens were randomly divided into four groups of teeth, each according to the resin cement used. Sixty cylinders were then luted with one of the four resin materials to dentin (GC EQUIA, Panavia F, Variolink II and Vertise). Then, specimens were stored in distilled water at 37 o C for one day. Shear bond strength of each specimen was measured using a universal testing machine at a crosshead speed of 0.5 mm/minute. The bond strength values were calculated in N, and the results were statistically analyzed using a Kruskal-Wallis and Bonferroni corrected Mann-Whitney U tests. The shear bond strength varied significantly depending on the resin materials used ( P < 0.05). The specimens luted with GC EQUIA showed the highest shear bond strength (25.19 ± 6.12), whereas, the specimens luted with Vertise flow (8.1 ± 2.75) and Panavia F (11.17 ± 3.89) showed the lowest. GC EQUIA material showed a higher shear bond strength value than other resin materials.

Surface Texture and Optical Properties of Self-Adhering Composite Materials after Toothbrush Abrasion.

This study evaluated the surface texture and optical properties of two self-adhering composites and a nanofilled composite before and after toothbrush abrasion. Vertise Flow (Kerr), Fusio Liquid (Pentron Clinical) and Filtek Z350 XT (3M ESPE) composites were divided into 3 groups (n = 6). Disks of 12 mm diameter and 2 mm thick were made. All materials were light-cured with a LED light source for 40 seconds. Analyses of surface roughness, gloss retention and color stability were performed 24 hours after light curing and after 20,000 brushing cycles. Data were analyzed with analysis of variance (ANOVA) and Tukey's test (α = 5%). Tukey's test ascertained that toothbrush abrasion resulted in rougher and matte surfaces for all composites tested. Filtek Z350 presented better gloss retention after abrasion. On surface roughness evaluation, there was no statistical difference between Fusio Liquid Dentin and Filtek Z350 resins (p > 0.05). Vertise Flow resin showed better color stability (ΔE), than the other two materials. Nanofilled material presented better gloss retention but it did not produce the best results in aspects related to surface roughness and color stability compared to self-adhering composites. A simulation of degradation process by using toothbrush abrasion produced a rougher and matte surface in all composites tested. The surface texture was not only related to filler's amount present in materials, but also with the organic matrix composition of them. The results suggested that the constant development of new materials, seeking for a technical simplification, seems an innovative attraction for dentist's clinical routine, even though larger studies are necessary to promote to everyone a better understanding and improvement of action and effectiveness of this new class of materials.

Colour Stability of Self-Adhesive Flowable Composites before and after Storage in Water

Objectives:The aim of this study was to compare colour stability of two self-adhesive flowable composites with four methacrylate-based composites (three flowable composites and one universal resin-based composite) after immersion in water at 60°C for 30 days.Methods:The study was conducted using the following five shade A2 flowable composites (n=30): one microhybrid (G-aenial Universal Flo), one universal (X-Flow), one nanohybrid (Premise flowable) and two self-adhesive (Vertise Flow and experimental GF-10) and one microhybrid universal resin-based composite (G-aenial Posterior). A spectrophotometer (CIEL*a*b* system) was used to measure colour stability before and after immersion. Statistical analysis was performed with one-way ANOVA and Fisher test.Results:Samples immersed in water at 60°C for one month showed a significant colour change in all groups (p&lt;.001) that was visually perceptible (∆E&gt;3.3). Experimental self-adhesive flowable (12.25±0.84) and X-Flow (11.56±3.26) composites showed higher levels of ∆E, while Premise flowable showed a lower level of colour change (3.47±1.26). These results approximated clinically acceptable colour change values (∆E≤3.3). Water ageing at 60°C produced a significant change in colour in all the composites. The high temperature may explain the degradation of the resin matrix.

Effect of different surface treatments on the microtensile bond strength of two self-adhesive flowable composites.

The aim of this study was to evaluate the effect of different surface treatments on the microtensile bond strength (μTBS) of two different self-adhesive flowable composite materials (SACs) to dentin. Forty extracted human molars were horizontally flattened to expose the dentin surfaces. The teeth were divided into eight groups according to the surface treatments (acid etching, Er:YAG laser quantum square pulse (QSP) mode, and Er:YAG laser medium-short pulse (MSP) mode at 10 Hz, 1.2 W, 120 mJ, and control-SiC) and SAC type (Vertise Flow and Fusio Liquid Dentin) (n = 5). Light cured 4-mm-high composite build-ups were made on the dentin surfaces, and the specimens were sectioned into serial sticks (n = 15). Later, the specimens were attached to microtensile testing machine and tensile force was applied at a crosshead speed of 1 mm/min until failure occurred. The failure modes were evaluated using a stereomicroscope at ×40 magnification, and one sample from each group was used for scanning electron microscopy (SEM) evaluation. The data were analyzed with two-way ANOVA and Tukey's HSD test (α = 0.05). In all surface treatment groups along with the control groups, Vertise Flow showed better μTBS than the Fusio Liquid Dentin with the exception of the Er:YAG MSP mode surface treatment (p < 0.05). Etching with phosphoric acid and the Er:YAG QSP mode surface treatment significantly increased the μTBS of Vertise Flow (p < 0.05). Etching with phosphoric acid, Er:YAG QSP mode surface treatment, and Er:YAG MSP mode surface treatment significantly increased the μTBS of Fusio Liquid Dentin (p < 0.05). The μTBS of Vertise Flow was higher than the μTBS of Fusio Liquid Dentin. The Er:YAG laser irradiation increased the μTBS of both self-adhesive flowable resin composites in two pulse modes tested (MSP or QSP). However, the highest μTBS was recorded when Vertise Flow was applied with acid etching.

Effect of thermal aging on microleakage of current flowable composite resins

Background/purposeTo evaluate the microleakage of Class V cavities restored with a new self-adhering resin composite after thermal cycling. Materials and methodsStandardized box-shaped Class V cavities were prepared on the buccal and lingual sides of 75 intact human molars (n = 150). The teeth were randomly divided into five groups of 30 cavities each and restored as follows: GroupVF: Vertise Flow (Kerr Corporation, Orange, CA, USA); Group OVF: OptiBond (Kerr) + Vertise Flow; Group SM: Clearfil SE Bond (Kuraray Medical Inc., Okayama, Japan) + Majesty Flow (Kuraray Medical Inc.); Group TM: Clearfil Tri-S Bond (Kuraray Medical Inc.) + Majesty Flow (Kuraray Medical Inc.); and Group UOA: Uni-etch acid (Bisco Inc., Schaumburg, IL, USA) + One-Step Bond (Bisco Inc.) + Aeliteflo (Bisco Inc.). The restorations were finished with aluminum oxide discs (Sof-Lex, 3M ESPE). The restorations were divided into three subgroups (n = 10) and subjected to 1000, 5000, and 15,000 thermal cycles. The teeth were immersed in 0.5% basic fuchsin solution for 24 hours. The dye penetration was examined under a stereomicroscope and scored. The results were statistically analyzed by Kruskal-Wallis, Mann-Whitney U, and Wilcoxon tests. ResultsThe Mann-Whitney U test revealed that for cementum leakage scores of 1000 cycled groups, Groups VF, UOA, and OVF showed higher microleakage than Groups TM and SM and the difference was statistically significant (P < 0.05). When the composite groups were compared for 5000 and 15,000 thermal cycles, no significant differences were detected for both enamel and cementum microleakage scores (P > 0.05). ConclusionThe sealing ability of the new self-adhering flowable composite is detected as similar to the traditional flowables when subjected to long term thermal aging.

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.

Microleakage of class v cavities restored with flowable composite materials

Introduction. Increasing requirements for durable fillings and marginal integrity have influenced the development of new materials and restorative techniques. Contemporary demands for esthetic restorations have encouraged the development of new composite material ?self-etch flowable composite?. The aim of this study was to test the marginal seal in small Class V cavities after restoration with self etch flowable composite material Vertise Flow and flowable composite Tetric Flow, both polymerised using conventional light-curing technique. Material and Methods. The study was conducted on 40 extracted human teeth (20 intact, 20 carious). Each group included 10 premolars and 10 molars. In all teeth two cavities class V of diameter 3?2?2 mm were prepared (buccal and lingual surface). On the buccal surface the cavities were filled with self etch flowable composite Vertise Flow (Kerr Dental Products), and on the lingual surface with flowable composite Tetric Flow (Ivoclar Vivadent) using appropriate adhesive system. Polymerisation was performed using LED lamp (Ivoclar Vivadent). Microleakage was tested with silver nitrate solution. Using stereoloupe with micrometer scale and six times magnification dye penetration was measured. Results. Mean dye penetration in intact molars restored with Vertise Flow was 3.41 ?m, while in intact molars restored with Tetric Flow it was 4.23 ?m. In intact premolars restored with Vertise Flow, the average dye penetration was 1.14 ?m and in intact premolars restored with Tetric Flow it was 3.90 ?m. Dye penetration in carious molars restored with Vertise Flow and polymerised using conventional polymerization technique was 3.66 ?m, while using Tetric Flow it was 7.94 ?m. In carious premolars restored with Vertise Flow dye penetration was 3.97 ?m, while with Tetric Flow it was 7.12 ?m. The total dye penetration was lower in intact compared to carious teeth. Greater dye penetration was found in molars compared to premolars. Conclusion. Vertise Flow showed better quality of bond with hard dental tissue than Tetric Flow when classical polymerization technique was used.

Shear bond strength of a new self-adhering flowable composite resin for lithium disilicate-reinforced CAD/CAM ceramic material.

PURPOSEThe purpose of this study was to evaluate and compare the effects of different surface pretreatment techniques on the surface roughness and shear bond strength of a new self-adhering flowable composite resin for use with lithium disilicate-reinforced CAD/CAM ceramic material.MATERIALS AND METHODSA total of one hundred thirty lithium disilicate CAD/CAM ceramic plates with dimensions of 6 mm × 4 mm and 3 mm thick were prepared. Specimens were then assigned into five groups (n=26) as follows: untreated control, coating with 30 µm silica oxide particles (Cojet™ Sand), 9.6% hydrofluoric acid etching, Er:YAG laser irradiation, and grinding with a high-speed fine diamond bur. A self-adhering flowable composite resin (Vertise Flow) was applied onto the pre-treated ceramic plates using the Ultradent shear bond Teflon mold system. Surface roughness was measured by atomic force microscopy. Shear bond strength test were performed using a universal testing machine at a crosshead speed of 1 mm/min. Surface roughness data were analyzed by one-way ANOVA and the Tukey HSD tests. Shear bond strength test values were analyzed by Kruskal-Wallis and Mann-Whitney U tests at α=.05.RESULTSHydrofluoric acid etching and grinding with high-speed fine diamond bur produced significantly higher surface roughness than the other pretreatment groups (P<.05). Hydrofluoric acid etching and silica coating yielded the highest shear bond strength values (P<.001).CONCLUSIONSelf-adhering flowable composite resin used as repair composite resin exhibited very low bond strength irrespective of the surface pretreatments used.

In vitro bonding effectiveness of new self-adhering flowable composite to calcium silicate-based material

The purpose of this study was to compare in vitro bonding effectiveness of Vertise Flow (VF), a new self-adhering flowable composite (FC), and Ultimate Flow (UF), a conventional FC, to BioAggregate (BA), and to investigate whether the use of self-etch or etch-andrinse adhesive improved the bond strength of VF to BA. Shear bond strengths of FC to BA were measured for this reason. Data were analyzed using Wilcoxon and Mann-Whitney U-tests (p=0.05). There were significant differences of bond strengths after 24- and 72-h (p<0.05, p<0.001). After 72-h, self-adhering FC may be used successfully with BA and no other adhesive, as an alternative to the combined use of conventional FC and self-etch adhesives. The use of etch-and-rinse adhesives with self-adhering FC may improve adhesion to BA.

Shear-Bond Strength of a New Self-Adhering Flowable Restorative Material to Dentin of Primary Molars

The aim of this study was to evaluate the shear bond strength to dentin of primary molars of a new self-adhering flowable resin composite with two ionomer-based cements and one flowable resin composite in combination with two different adhesive systems. Fifty primary molars were grinded on the occlusal surface to obtain flat dentin substrate and randomly divided into 5 groups (n = 10): OFL:Phosphoric Acid/Optibond FL/Premise Flow; OAO:Optibond All-In-One/Premise Flowable; II:Polyacrylic Acid/Fuji II; IX:Polyacrylic Acid/Fuji IX; V:Vertise Flow. Cylinders (3mm diameter - 5mm height) of restorative material were built-up in three increments over the dentin surfaces. A shear load was applied until failure. Bond strength values were statistically analysed with Kruskall-Wallis ANOVA followed by Dunn's test (P < .05). Differences in failure mode distribution were assessed with Chi-square (P < .05). OFL and OAO recorded significantly higher bond strengths than the other groups. Adhesive failures were evident in all groups except OFL and OAO, in which also cohesive failures in dentin were observed. Vertise Flow established on primary dentin bond strengths values similar to those of glass ionomer cements routinely used for restorations of primary teeth. The combination of flowable resin with etch-and-rinse or all-in-one adhesives obtained higher bond strength values, thus involving a more complex handling.

Reinforcement of Teeth With Simulated Coronal Fracture and Immature Weakened Roots Using Resin Composite Cured by a Modified Layering Technique

The purpose of this study was to evaluate the strengthening effect of resin composite, cured by a modified layering protocol, for teeth with simulated coronal fracture and weakened immature roots. Fifty maxillary teeth were decoronated and their apices sectioned to standardize the length to 12 mm. Prepared teeth were equally distributed into five groups. Group 1VF root apices were flared with Pesso drills up to size 6. The roots were flared until a dentin thickness of only 1 ± 0.2 mm remained. Root ends were filled with mineral trioxide aggregate. The canals were backfilled with Vertise Flow following a modified layering protocol using two light-transmitting posts size 6 and 3. Next, a DT light post size 2 was cemented using the same material. Groups 2TS/MF and 3ED/PF were prepared and cured in the same way as group 1VF but filled with Clearfil Tri-S Bond/Majesty Flow and ED Primer II/Panavia F2.0 respectively. Group 4UF was similarly prepared but left unfilled (control). In group 5NW, roots were unflared but similarly filled as in group 3ED/PF. After 24 hours of storage, the fracture load was measured. The degree of cure for each tested material was indirectly measured using microhardness at different root levels (cervical, middle, and apical). Data were analyzed using one-way analysis of variance followed by Newman-Keuls post hoc test. Fracture load results revealed that groups 1VF and 2TS/MF had no statistically significant difference from group 5NW (p>0.05). For each tested material, no significant difference was found among microhardness values at different root levels. It may be possible to reinforce the teeth with coronal fracture and immature weakened roots to be comparable with unweakened ones when composite is applied and cured by the modified layering technique.

Composite-induced toxicity in human gingival and pulp fibroblast cells

Objective. The most important requirement for a material to be used in medical applications is its biocompatibility. Dental composite materials come into direct contact with oral tissues, especially gingival and pulpal cells. This study was performed to evaluate possible DNA damage in cells of human origin exposed to dental composites in vitro using a cytogenetic assay. Materials and methods. Two composite resins (Vertise Flow, Kalore) were tested on human gingival and pulp fibroblasts using the acridine orange/ethidium bromide viability staining and alkaline comet assay. Cultures were treated with polymerized composites in two different concentrations (20 mg/ml, 40 mg/ml) for 14 days. Chi-square and Kruskall-Wallis non-parametric test were used for the statistical analysis (p < 0.05). Results. Significant cytotoxicity was observed for 40 mg/ml of Vertise Flow in both cultures, while Kalore (40 mg/ml) showed cytotoxic effect only on human pulp fibroblasts. A significant level of DNA damage was detected for both materials and concentrations, in both cell cultures. Conclusion. If the two cell cultures are compared, the pulp cells were more sensitive to the cyto/genotoxic effects of dental composites. Based on the results, one can conclude that the use of tested materials may cause cellular damage in gingival and pulp fibroblasts in vitro.

Bond Strength to Unground Enamel and Sealing Ability in Pits and Fissures of a New Self-Adhering Flowable Resin Composite

To evaluate the applicability as a sealant of a new self-adhering flowable resin composite (Vertise Flow, Kerr, VF) by assessing shear bond strength (SBS) to unground enamel and microleakage (microLKG) in sealed pits and fissures. Marketed sealants to be used in combination with phosphoric acid (Guardian Seal, Kerr, GS) or with a self-etch adhesive (Adper Prompt-L-Pop/Clinpro Sealant, 3M ESPE, CS) were compared to VF. For SBS testing on unground enamel 10 molars per group were used. For microLKG assessment, pits and fissures sealing was performed in 12 molars per group. The sealed teeth were immersed in a 50% weight silver nitrate solution for 24 hours and the extent of interfacial leakage was measured. Between-group differences in SBS were assessed using One-Way Analysis of Variance (ANOVA), followed by Tukey test (p < 0.05). microLKG data were analyzed with Kruskall-Wallis ANOVA (p > 0.05). SBS of VF was statistically similar to that measured by CS and higher than that of GS. Interfacial leakage was similar in the three groups. The finding of satisfactory bond strength and sealing ability of VF when compared to the marketed sealants encourages the use of VF in pit and fissure sealing.

In vitro comparison of mechanical properties and degree of cure of a self-adhesive and four novel flowable composites

To compare a self-adhesive with two low-shrinkage and two regular flowable resin-based composites (RBCs) in terms of degree of conversion (DC) as well as micromechanical (indentation modulus [E]; Vickers hardness [HV]) and macromechanical properties (flexural strength [σ], modulus of elasticity [Eflexural]). DC was investigated by an ATR-FTIR spectrometer at clinically relevant filling depths (0.1 mm, 2 mm, 4 mm, 6 mm bulk, 6 mm incremental) and irradiation times (10 s, 20 s, 40 s). Micro- and macromechanical properties were measured with an automatic microhardness indenter and a three-point bending test device after curing the specimens for 20 s and storing them in distilled water for 24 h at 37°C. Fillers were visualized using a field emission scanning electron microscope (FE-SEM). Results were evaluated using one-way ANOVA, Tukey's HSD post-hoc test, Pearson's correlation and a multivariate analysis (α = 0.05). A Weibull analysis was used to assess σ. N'Durance Dimer flow (65.66%) reached the highest DC (at 2 mm depth, 20 s irradiation). In terms of macromechanical properties, EcuSphere-Flow (129.82 MPa) for σ and Synergy D6 Flow (3.74 GPa) for Eflexural reached the highest values. The highest micromechanical properties were measured for the self-adhesive RBC (Vertise Flow; E = 10.81 GPa, HV = 60.20 N/mm2). Reliability was highly influenced by filler weight (η2 = 0.77) and volume (η2 = 0.99) proportion. In the present study, the self-adhesive RBC showed the highest reliability, highest DC (together with one of the low-shrinkage RBCs), and highest micromechanical properties as well as good macromechanical properties. Moreover, a curing time of 40 s and an incremental thickness not exceeding 2 mm appeared to be necessary for such results.

Self-adhesive restoratives as pit and fissure sealants: A comparative laboratory study

ObjectivesTo evaluate the properties of self-adhesive restorative materials used as sealants in comparison with sealants with hydrophobic or hydrophilic monomers. MethodsThe self-adhesive materials tested were Fusio (FS) and Vertise-Flow (VF) and the sealants Embrace Wetbond (EM/hydrophilic) and Helioseal-F (HS/hydrophobic). The properties tested were: (a) degree of cure (%DC, n: 5, ATR-FTIR), (b) extent of oxygen inhibition (n: 5, transmission optical microscopy), (c) flow (n: 5, ASTM D-4242 method), (d) hardness (VH0.2kp/10s dry/1w in water), (e) adaptation, microleakage and fissure penetration (n: 10, 1% fuschin dye, reflection optical microscopy and ESEM). Statistical analysis was performed by one-way ANOVA plus Tukey test (a–d), Fisher's exact and Kruskal–Wallis plus Tukey tests (e) at a 95% confidence level. ResultsVF showed the highest %DC(76.1) followed by HS(68.7) and EM(61.3), FS(59.2). HS demonstrated the highest extent of oxygen inhibition (23μm vs. 13–10μm of the rest). EM and HS exhibited the greatest flow, followed by FS and VM. The VHN(0.2kp/10s) ranking before and after 1week water exposure was FS≥VF>EM≥HS. Water storage increased VF and reduced HS values. The lowest adaptation and microleakage scores were found in HS. FS and VF after alumina sandblasting showed the worst adaptation and leakage scores, that were improved after acid-etching. Improved fissure penetration was found in HS, EM and FS, VF after acid-etching. SignificanceAlthough the self-adhesive materials presented improved setting characteristics, their low flow affected fissure penetration capacity. When combined with enamel acid-etching, adaptation and microleakage scoring were substantially improved in comparison with enamel sandblasting. The sealant with the hydrophobic monomers demonstrated the best sealing characteristics.

Interfacial Nanoleakage and Bonding of Self-Adhesive Systems Cured with a Modified-Layering Technique to Dentin of Weakened Roots

The purpose of the study was to evaluate the nanoleakage and bond strength of different self adhesive systems cured with a modified-layering technique (MLT) to dentin of weakened roots. Twenty-one maxillary incisors were decoronated and then root canals were instrumented and obturated with the cold lateral compaction technique. Weakened roots were simulated by flaring root canals until only 1 mm dentin thickness remained. Teeth were distributed into three groups. The canals were backfilled with Vertise Flow (VF group), a self-adhering system, following a modified-layering technique using two light-transmitting posts, sizes 6 and 3. DT Light Post size 2 was cemented using the same material. Remaining roots were prepared and cured in the same way as the VF group. However, in the TS/MF group, Clearfil Tri-S Bond (TS) adhesive and Clearfil Majesty Flow (MF) composite were used, while in the ED/PF group, ED primer II (ED)/Panavia F2.0 (PF) were used. After one week of storage, each root was sectioned to obtain six slices (two slices from each root third: coronal, middle and apical) of 0.9 ± 0.1 mm thickness. Interfacial nanoleakage expression was analyzed using a field emission scanning electron microscope (FEG-SEM), and the micro push-out bond strength (μPOBS) was measured at different root regions. Modes of failure were also determined using SEM. Data were statistically analyzed using two-way analysis of variance with repeated measures and Tukey post hoc test (p≤0.05). With MLT, all adhesive systems showed nanoleakage. For μPOBS, there was a statistically significant effect for adhesive systems (p<0.001) but not for root region (p<0.64) or for their interaction (p=0.99). Tukey post hoc test revealed that the bond strength of the VF group was significantly higher than the TS/MF and ED/PF groups for all root regions. All of the tested self-adhesive systems cured using MLT had slight nanoleakage and were not sensitive to root regional differences. Self-adhering systems had higher bond strength than self-etch adhesives.

Marginal seal evaluation of self-etch flowable composite materials

Introduction. The biggest drawback of composite materials is polymerization contraction and the existence of microcracks, therefore the market is now offering a wide variety of new composite materials. The aim of this study was to evaluate the marginal seal using dye method of class V cavities restored with self-etching flowable composite material Vertise Flow polymerized with different light-curing techniques. Material and Methods. The study was conducted on 60 extracted intact human teeth (30 premolars, 30 molars). Two cavities Class V (3?2?2 mm) were prepared in all teeth. Cavities on buccal surfaces were filled with self-etching flowable composite Vertise Flow (Kerr Dental Products), and on lingual with flowable composite Tetric Flow (Ivoclar Vivadent) using the corresponding adhesive systems. Polymerisation was performed using Bluephase Led flashlight C8 (Ivoclar Vivadent). Microleakage was tested using dye in a silver nitrate solution. Dye penetration was measured using stereo loupes with micrometer scale and six times magnification. Results. Linear dye penetration in intact molars restored using the classical polymerization technique and Vertise Flow composite was 3.41 ?m while with Tetric Flow it was 4.23 ?m. In intact molars restored using soft-start polymerization technique and Vertise Flow the dye penetration was 1.25 ?m while for Tetric Flow it was 4.23 ?m. Mean dye penetration in intact molars restored using pulse curing technique and material Vertise Flow was 1.02 ?m while for the composite Tetric Flow it was 4.35 ?m. In intact premolars restored using conventional curing technique and Vertise Flow dye penetration was 1.14 ?m while for Tetric Flow it was 3.90 ?m. Dye penetration in intact premolars restored using soft-start polymerization technique and Vertise Flow was 0.75 ?m while for Tetric Flow it was 3.15 ?m. Using a pulse polymerization technique and Vertise Flow in intact premolars dye penetration was 1.45 ?m while for Tetric Flow it was 3.76 ?m. Conclusion. Vertise Flow, self-etching flowable composite showed better marginal seal than flowable composite resin Tetric Flow. Smaller microcracks with Vertise Flow were confirmed after applying all three light-curing polymerization techniques.

Bonding performance of a newly developed step-less all-in-one system on dentin

The purpose of this study was to evaluate the short-term µTBS (Micro-tensile bond strength) and microscopic (SEM and TEM) observation of four recent adhesives. One adhesive was an experimental step-less 1-step system (LLB-2, Tokuyama Dental), which is an all-in-one system without the light-curing step in the application process. The other two were self-adhering light-cured flowable composite resin systems FLD (Fusio Liquid Dentin, Pentron Clinical Technologies) and VF (Vertise Flow Dental Restorative Materials, Kerr Corporation), which combine all the bonding steps together. A 2-step self-etching system MG (Clearfil MegaBond, Kuarary Medical) was employed as the control group in this study. The µTBS of MG was the highest (79.0 MPa) followed by that of LLB-2 (63.1 MPa), FLD (23.6 MPa), and VF (13.1 MPa). The microscopic observations showed that MG and LLB-2 had an approximately 20 µm and 5 µm adhesive layer respectively, without bubble or gap-formation at the resin-dentin interface, which were found in FLD and VF.