Self-adhering Flowable Composite Research Articles

Clinical evaluation of self-adhering flowable composite versus conventional flowable composite in conservative Class I cavities: Randomized controlled trial.

Background:Self-adhering flowable composite (SAFC) minimized the time-consuming application procedures encountered with the traditional adhesive systems and restorative materials. Self-adhering composite combines the merits of both adhesive and restorative material technologies (8th generation) in a single product, bringing new horizons, and ambitions to restorative procedures.Aim:The aim of this study was to evaluate the clinical performance of SAFC compared to conventional flowable composite in conservative Class I cavities.Materials and Methods:In a split-mouth design, after cavity preparation, 18 patients with conservative Class I cavities received randomly two pairs of restorations, either Vertise™ flow or Filtek™ Z350 XT Flowable combined with Scotchbond™ Universal Etchant and Single Bond Universal, all materials were applied according to the manufacturer's instructions. Restorations were evaluated at baseline and after 6 months by two calibrated assessors using the modified United States Public Health Service criteria measuring (retention, postoperative hypersensitivity, color match, marginal adaptation, and marginal discoloration).Statistical Analysis:Chi-square test was used to compare between flowable composite materials after different follow-up periods, Wilcoxon signed-rank test was used to explore changes over follow-up periods. A value of P ≤ 0.05 was considered statistically significant. Results: At baseline and 6 months, there was no statistically significant difference between both materials for all tested outcomes.Conclusions:SAFC has shown clinical performance similar to conventional flowable composite after 6 months of clinical service.

Comparative evaluation of bond strength of self-adhering flowable composites to the dentin prepared with different burs: An in vitro study.

Aim:The aim of this study was to evaluate the shear bond strength (SBS) of self-adhering flowable composites on the dentinal surface prepared with carbide and diamond burs.Materials and Methods:A total of 64 extracted mandibular molars were mounted on acrylic resin blocks, and the coronal part of the dentin was exposed and polished. Then, they were divided into Group 1 and Group 2 for carbide and diamond bur preparation, respectively. Two teeth in each group were evaluated under scanning electron microscope, ×500, to view the surface changes following the bur preparation. The remaining teeth were subdivided into Groups A, B, and C to be restored with Constic, Dyad™-flow, and Tetric N Flow composites, respectively. Then, the specimens were stored in distilled water at 37°C for 24 h, and then subjected to universal testing machine to evaluate the SBS and viewed under light stereomicroscope to evaluate the type of failure.Statistical Analysis:SPSS version 22 (IBM Corp) for Windows was used for statistical analysis. The values were subjected to ANOVA followed by Bonferroni post hoc analysis. The values between the groups were analyzed using Student's unpaired t-test.Results:Statistically significant differences in the SBS values were seen between Groups A and C (P < 0.001) and Groups B and C (P < 0.001). Statistically significant differences were seen in SBS values of Dyad-flow (Group B) (P < 0.004) and Tetric N flow (P < 0.007) for surfaces prepared with carbide and diamond burs.Conclusion:It was concluded that the SBS of Tetric-N Flow was higher than that of the experimental groups of Constic and Dyad-flow. Dentinal surface preparation with carbide bur resulted in higher SBS for Tetric N Flow and Dyad-flow but not for Constic.

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 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.

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.

SHEAR BOND STRENGTH OF SELF ADHERING FLOWABLE COMPOSITES AFTER PRELIMINARY ACID ETCHING OF DENTIN

INTRODUCTION: Many advances in flowable composites have been developed in the last few years, including the introduction of selfadhering flowable composites (SAFCs) that do not require the application of adhesive systems. OBJECTIVES: The objective of this study was to evaluate the influence of preliminary etching with 37% phosphoric acid on the shear bond strengths of two SAFCs (Vertise Flow and Fusio Liquid Dentin) to dentin. MATERIALS AND METHODS: Sixty sound human permanent molars were collected and prepared to expose the mid-coronal dentin. Dentin specimens were randomly divided into six groups (n=10) according to the material applied: (1) Vertise Flow (VF); (2) Fusio Liquid Dentin (FLD); (3) Gel Etchant/Vertise Flow (GE/VF); (4) Gel Etchant/Fusio Liquid Dentin (GE/FLD); (5) Optibond all-in-one/Premise Flowable (Opti-A/PF); (6) Gel Etchant/ Optibond all-in-one/Premise Flowable (GE/Opti-A/PF). Specimens were subjected to shear bond strength (SBS) test. Failure modes were evaluated under stereomicroscope and assessed using Adhesive Remnant Index (ARI) scores. Data were collected and statistically analyzed using ANOVA F-test and Chi-square test (p < 0.05). RESULTS: Group 6 (GE/Opti-A/PF) recorded the highest mean SBS (16.39 ± 2.418 MPa), while Group 1 (VF) recorded the lowest mean SBS (4.32 ± 0.993 MPa). The one-step self-etch adhesive Optibond all-in-one with and without a separate etching step had significantly higher mean SBS than those of the two SAFCs. Preliminary etching of dentin significantly increased the SBS of only Vertise Flow. CONCLUSIONS: The bonding performance of the 1-step self-etch adhesive (SEA) (Opti-A) was considerably better than those of the two SAFCs. Preliminary acid etching of dentin enhances the bonding performance of VF.

Shear Bond Strength and Tooth-Composite Interaction With Self-Adhering Flowable Composites.

To evaluate the tooth-composite interaction (A) and shear bond strength (SBS; B) of self-adhering flowables. (A) Thirty-two human molars with one Class V cavity were restored with Vertise Flow (VF), Fusio Liquid Dentin (FLD), an experimental self-adhering flowable (EF), or Adper Prompt-L-Pop/Filtek Supreme XT Flowable (PLP). Teeth were prepared according to laboratory standard and stored in water (24 hours, 37°C). Microleakage (ML; percentage interface length at enamel [E]/dentin [D]) and tooth-composite interaction were investigated. (B) The buccal surface of 160 embedded human molars was abraded to expose an enamel/dentin area of diameter ≥3 mm. Composite specimens were produced on enamel/dentin with VF, FLD, EF, or PLP. Prior to loading, 80 samples were water stored (24 hours, 37°C) and 80 thermocycled (5°C-55°C, 1500 cycles). The SBS was measured, and failure modes were classified by scanning electron microscopy. Kruskal-Wallis, Mann-Whitney U, and Fisher exact tests were performed (α=0.05). (A) At enamel margins, EF and VF showed significantly lower ML than did FLD and PLP (pi≤0.009; 81%-89%); in dentin, lower values resulted with FLD and VF compared with PLP and EF (pi≤0.01; 77%-94%). Adhesive tags at E were consistently verifiable with EF and VF but irregularly with FLD and PLP. At D, tags were detectable with all systems. (B) In all groups, SBS decreased by up to 97% after thermocycling. It was generally diminished with self-adhering flowables (E: 50%-98%, D: 59%-98%; pi<0.02). More cohesive defects were observed with PLP (pi<0.009). Tooth-composite morphology and bond strength indicate that the clinical use of self-adhering flowables must be pursued cautiously.

BOND STRENGTH AND INTERFACIAL MORPHOLOGY EVALUATION OF SELF-ADHERING FLOWABLE COMPOSITES

BOND STRENGTH AND INTERFACIAL MORPHOLOGY EVALUATION OF SELF-ADHERING FLOWABLE COMPOSITES

Micromorphology and bond strength evaluation of adhesive interface of a self-adhering flowable composite resin-dentin: Effect of surface treatment.

This study evaluated the effect of dentin surface treatment on the micromorphology and shear bond strength (SBS) of a self-adhering flowable composite, Vertis Flow (VF). Flat dentin surfaces obtained from sixty extracted human molars were divided into six groups (n = 10) according to the following surface treatments: (G1) control, no treatment; (G2) self-etching adhesive, Optibond All-in-One; (G3) phosphoric acid etching for 15 s; (G4) polyacrylic acid for 10 s; (G5) EDTA for 60 s; and G6) sodium hypochlorite (NaOCl) for 15 s. After restoration using VF, SBS was measured in MPa. Data were analyzed using one-way ANOVA and Tamhane test (α = 0.05). Six additional specimens were prepared for scanning electron microscopy analysis. SBS was significantly affected by surface treatment (P < 0.001). SBS of six groups from the highest to the lowest were as follows: (G3) 13.5(A); (G5) 8.98(AB); (G2) 8.85(AB); (G4) 8.21(AB); (G1) 7.53(BC); and (G6) 4.49(C) (groups with the same superscript letter were statistically similar). Morphological analysis revealed numerous long resin tags at the adhesive interface for acid-etched group, with a few short resin tags for the control group and small gap formation for NaOCl-treated group. In conclusion, dentin surface treatments tested differently affected bonding performance of VF; only acid-etching effectively improved this.

The shear bond strength of MTA with three different types of adhesive systems: An in vitro study.

Aim:To evaluate the shear bond strength of MTA with three different types of adhesive systems- self-adhering flowable composite, etch and rinse adhesive system and self etch adhesive system.Methodology:MTA specimens (n = 60) were prepared using cylindrical acrylic blocks, having a central cavity with 4 mm diameter and 2 mm depth. MTA was mixed and placed in the prepared cavity, and was covered with a moist cotton pellet and temporary filling material. The specimens were divided into 3 groups which were further divided into 2 sub-groups (45 Minutes and 24 hours). After the application of bonding agents composite resin was placed over the MTA surface. The specimens were tested for shear bond strength and readings were statically analyzed.Result:After 24 hrs the mean value of etch and rinse group was significantly higher than self etch and the self adhering composite groups. Among the 45 minutes groups there were no significant difference.Conclusion:In single visit after 45 minutes self adhering flowable can be used successfully as a final restorative material in place of conventional flowable composite without using any alternative adhesive system over MTA.

The Effect of Energy Densities on the Shear Bond Strength of Self-Adhering Flowable Composite to Er:YAG Pretreated Dentin.

Objective. To investigate the shear bond strength of self-adhering flowable resin composite, to dentin, after exposing it to Er:YAG laser radiation, at different energy densities. Materials and Methods. Sixty freshly extracted human third molars were randomly divided into five groups (n = 12). In the control group, dentin was left unirradiated, whereas, in the other four groups, dentin was irradiated with Er:YAG laser in noncontact mode (MSP mode = 100 µs; 10 Hz; beam diameter: 1.3 mm; speed of 1 mm/second; air 6 mL/min; and water 4 mL/min), and respectively, with the following level of energy (50 mJ, 60 mJ, 80 mJ, and 100 mJ). Then, self-adhering flowable resin composite was bonded to all prepared dentin surfaces. Shear bond strength (SBS) was applied and fractured surfaces were examined using scanning electron microscopy. Results. SBS values showed significant differences in 60 mJ (P < 0.05) compared to other groups. Morphological evaluation revealed tags or plugs in dentinal tubules, especially when 60 mJ and 80 mJ were used. All four groups tended to leave more residues on the dentin surface, than the control group. Conclusion. Er:YAG dentin irradiation may enhance SBS of the self-adhering flowable resin composite when it is used at the appropriate low level of energy density.

CLINICAL EVALUATION OF SELF-ADHERING FLOWABLE COMPOSITE IN NON-CARIOUS CERVICAL LESIONS

Introduction: The clinical management of non-carious cervical lesions is a challenge concerning restoring procedures because the lesions have non-retentive cavity shape and margins lying on dentin or cementum which are unfavorable for bonding. Objective: To evaluate the clinical performance of two self-adhering flowable composites compared with flowable composite and resin modified glass ionomer in restoration of non-carious cervical lesions for 1 year. Materials and Method: A total of 60 non-carious cervical lesions (15 for each material) were restored with self-adhering resin flowable composites (VertiseTM Flow and FusioTM Liquid Dentin), flowable composite with ExciTE F dental adhesive system and resin modified glass ionomer. The outer surface of the dentinal wall was roughened with a water-cooled high-speed diamond bur. Occlusal or incisal enamel margins were beveled, and no mechanical retention was performed. The restorations were re-evaluated with the modified United States Public Health Services (USPHS) criteria at baseline, 3, 6 and 12 months. Results: After 1 year, 14 of the 15 Vertise Flow and 12 of the 15 Fusio Liquid Dentin restorations were in a clinically unacceptable condition due to retention failure. The success rates of Vertise Flow (6.7%) and Fusio Liquid Dentin (20%) were less when compared to the success rate (80%) for the 2-step etch and rinse/Flowable composite and (60%) for the resin modified glass ionomer restorations (P-value < 0.001) Conclusion: The clinical performance of the self-adhering resin flowable composites showed higher failure rate than other restorative materials after 1 year of clinical use.

Comparative evaluation of shear bond strength and nanoleakage of conventional and self-adhering flowable composites to primary teeth dentin.

Background:The latest advancement in adhesive dentistry is the development of self adhering flowable composite resin which incorporates the self-etch adhesion technology to eliminate the steps of etching, rinsing, priming and bonding. Few studies have addressed resin bonding to primary teeth.Aim:The aim of this study was to compare the shear bond strength and nanoleakage of conventional and self adhering flowable composites to primary teeth dentin.Settings and Design:This study was conducted in the Department of Pedodontics and Preventive Dentistry, I.T.S Dental College, Hospital and Research Centre, Greater Noida; in association with the Department of Mechanical Engineering, I.T.S Engineering College, Greater Noida; and the Advanced Instrumentation Research Facility (AIRF), Jawaharlal Nehru University, New Delhi.Materials and Methods:Sixty of the ninety primary teeth were evaluated for shear bond strength and thirty for nanoleakage. The samples were divided into three groups; Group I – Dyad Flow (Kerr), Group II – Fusio Liquid Dentin (Pentron Clinical Technologies) and Group III – G-aenial Universal Flo (GC). Shear bond strength was determined using a universal testing machine. Nanoleakage pattern was observed under scanning electron microscope.Results:The shear bond strength of conventional flowable composite was significantly greater than self adhering flowable composite (p<0.05). Nanoleakage scores of both conventional and self adhering flowable composites were comparable.Conclusions:Self adhering flowable composites combine properties of composites and self etch adhesives, eliminating the need for separate bond application that simplifies direct restorative procedure. The evolution of self adhering materials could open new horizons for pediatric dentistry.

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.

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.

Hygroscopic dimensional changes of self-adhering and new resin-matrix composites during water sorption/desorption cycles

Objectives To study hygroscopic dimensional changes in new resin-matrix composites during water sorption/desorption cycles. Methods Five materials were examined: a self-adhering flowable composite: Vertise ® Flow (VF), a universal composite: GC Kalore (GCK), two micro-fine hybrid composites: GC Gradia Direct Anterior (GDA) and GC Gradia Direct Posterior (GDP), and a posterior restorative composite: Filtek ® Silorane (FS). Five disk-shaped specimens of each material were prepared (15 mm diameter × 2 mm thickness) according to ISO 4049. The mean diameter of each specimen was measured by a custom-built laser micrometer (to a resolution of 200 nm) periodically over 150 d water immersion and 40 d recondition periods at (37 ± 1) °C. Perspex controls were used. Data analysis was performed by repeated measures ANOVA, one-way ANOVA and Tukey's post hoc test ( p < 0.05). Results Differences in hygroscopic expansion were found for all test materials during sorption, ranging from 0.74% (±0.05) for FS to 4.82% (±0.13) for VF. The differences were significant for all materials ( p < 0.001), except between GCK and GDA. The mathematical relationship between diametral expansion and square root of time was non-linear. VF exhibited significant dehydration shrinkage. Significance The silorane composite FS had the lowest hygroscopic expansion. The extent of compensation of polymerization shrinkage by hygroscopic expansion depends on materials, specimen dimensions and time-scale. So the clinical situation must be taken into consideration in the application of these findings.

Metronidazole in in cariology: II. The bactericidal efficacy of metronidazole in vivo against bacteria in lesions of human carious dentine : Iwaku M., Hoshino E.,Kota K. et al. (1987) Jap. J. Conserv. Dent.30, 1444–1448

To evaluate the microleakage of Class V cavities restored with a new self-adhering resin composite after thermal cycling.Standardized 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.The 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).The sealing ability of the new self-adhering flowable composite is detected as similar to the traditional flowables when subjected to long term thermal aging.