Shear Bond Strength of Self-Adhesive Composite Containing TiO2 and SiO2 Nanoparticles with an Additional Etching Step for Orthodontic Brackets Bonding to Enamel

Introduction: Recently, nanoparticles such as nano-TiO2 have been added to some dental materials for enhancing dental carries prevention due to their antibacterial activity. Aim: This study aimed to assess the shear bond strength of a self-adhesive composite containing TiO2 and SiO2 nanoparticles for orthodontic bracket bonding. Materials and methods: This in vitro, experimental study was done on 70 extracted human premolars divided into 7 groups. Six groups of Vertise Flow self-adhesive composite samples were prepared: without any nanoparticles, with 0.5% and 1% TiO2 nanoparticles, 0.5% and 1% SiO2 nanoparticles, and 1% mixture of TiO2 and SiO2 nanoparticles so that nano-hybrid composites were prepared. Metal brackets were bonded with these samples as well as Transbond XT as the control group. The shear bond strength of the brackets to enamel was measured using a universal testing machine. The adhesive remnant index (ARI) score was also determined by a stereomicroscope. Data were analyzed by one-way ANOVA, Tukey&rsquo;s test and Kruskal-Wallis test. Results: The shear bond strength of the groups was significantly different (p=0.000). Pairwise comparisons revealed that the bond strength of Transbond XT group was significantly higher than others (p<0.05), followed by the 1% TiO2 group with significant differences with Vertise Flow and 0.5% TiO2 groups. The lowest value belonged to Vertise Flow with no nanoparticles. The ARI scores was different in the control group (p=0.000). Conclusions: Adding TiO2 and SiO2 nanoparticles to Vertise Flow self-adhesive composite not only did not adversely affect its shear bond strength, but also slightly increased it. Overall, the self-adhesive nano-hybrid composite containing TiO2 and/or SiO2 nanoparticles, following an additional etching step would be acceptable for bracket bonding and can be used clinically to benefit from the antimicrobial activity of these nanoparticles.

Evaluation of Newly Introduced Bioactive Materials in Terms of Cavity Floor Adaptation: OCT Study

Objective. The aim of the present study was to evaluate the adaptation of newly introduced bioactive restorative materials to the cavity floor using cross-polarization optical coherence tomography (CP-OCT). Materials and Methods. Round class V cavities were prepared on the proximal surfaces of sixty non-carious human anterior teeth (0.5 mm depth × 4 mm diameter), which were divided into groups according to the restorative material (n = 15). In the VF group, Vertise flow composite (Kerr, Orange, CA, USA) was used, in the BF group, Beautifil II composite (Shofu, Koyoto, Japan) was used, and in the AB group, ACTIVA BioACTIVE composite (Pulpdent, Watertown, NY, USA) was used. Cavities were restored using the bulk filling technique and cured according to the manufacturers’ instructions. Then, the specimens were immersed in a contrasting agent, and image acquisitions were taken by CP-OCT to calculate the adaptation percentage by using an image analysis software. Results. B-scans showed a diffuse bright band of white pixels at the tooth-resin interface that was interpreted as a micro-gap present between the cavity floor and restorative material. The Kruskal-Wallis test showed a statistically significant difference between all tested groups with the AB group representing the least gap formation, followed by the BF group, and then the VF group, which demonstrated the highest gap formation. Conclusions. In class V cavities, better adaptation to the cavity floor can be obtained when using ACTIVA BioACTIVE more than Vertise flow and Beautifil II composites. In addition, CP-OCT is considered a non-destructive imaging tool that helps in evaluating the quality of the tooth-restoration interface when bioactive composites are used.

Evaluation of Microshear Bond Strength of Self-Adhesive Versus Conventional Flowable Resin Composite to Sound and Affected Dentin: An In Vitro Study

Objectives: This study aimed to compare the microshear bond strength (µSBS) of self-adhesive flowable composite and conventional bonded flowable composite to sound and caries affected dentin. Materials and Methods: In this in vitro study, a total of freshly extracted 40 human molar teeth were used. The occlusal surface was sectioned to expose dentin for µSBS test. The teeth were randomly divided into 2 groups according to the type of flowable composite used into two groups (n=20): group A: self- adhesive flowable composite (Vertise flow), group B: Filtek Z350-XT flowable composite and one-step self-etch adhesive Adper Easy One. A plastic cylindrical mold was used to construct resin composite cylinders (0.8mm diameter x 1mm length) on the sound and caries affected exposed dentin and filled with flowable composite restorative materials according to manufacturer’s instructions. The samples were then immersed in distilled water at 37°C for 24 hours, and underwent µSBS test at a crosshead speed of 0.5 mm/min. Data were analyzed using Student's t-test to compare between the two materials as well as to compare between sound and caries affected dentin. Results: The mean values of µSBS of Filtek Z-350XT to sound and caries affected were 26.6 and 26.7 MPa respectively. The mean µSBS of Vertise Flow to sound and affected were 13.2 and 17.9 MPa respectively. With sound dentin FiltekZ-350XT showed statistically significant higher µSBS than Vertise flow. With caries affected dentin, there was no statistically significant difference between the two materials. There was no statistically significant difference between µSBS of sound and caries affected dentin within each material. The significance level was set at P ≤ 0.05. Conclusions: Within the limitations of this study, the conventional flowable composite yielded the highest µSBS to sound dentin. There was no statistical significant difference in µSBS of self-adhesive and conventional flowable to caries affected dentin. Key words: Composite Resins; Dentin; microshear.

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

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

Evaluation of bond strength of self-adhesive resin composite repairs

ABSTRACT Objective: To evaluate the bond strength of repairs with the self-adhering flowable composite Vertise Flow (Kerr) and a conventional composite resin Filtek Z350 (3M ESPE) subjected to different surface treatments. Methods: Forty specimens were divided into four groups: ZV (Filtek Z350 + Vertise Flow, without prior treatment); ZAV (Z350 + Vertise Flow with prior treatment with Single Bond Universal Adhesive System (3M ESPE)); ZAZ (Filtek Z350 + Filtek Z350 with prior treatment with Single Bond Universal Adhesive System (3M ESPE)); VV (Vertise Flow + Vertise Flow, without prior treatment). After 15 days of storage, the specimens were subjected to microtensile tests (Kratos IKCL3-USB, SP, Brazil), with speed of 0.5 mm/min and 20kg load. For statistical analysis, ANOVA with Tukey tests were used (p < 5%). Results: The mean values of the bond strength were highest respectively in the groups: ZV (36.07 ± 37.63); ZAZ (24.04 ± 28.51); VV (19.39 ± 28.24) and ZAV (16.06 ± 15.66). The bond strength of the repairs between the groups presented satisfactory results. Conclusion: The self-adhesive composite resin Vertise Flow seems to be a viable and fast alternative for composite resins repairs.

Bonding Effectiveness of Contemporary Materials in Luting Glass-Ceramic to Dentine: An In Vitro Study

Aim: To evaluate the shear bond strength (SBS) of resin cements, flowable composites, and a preheated composite in luting glass-ceramic to dentin. Materials and Methods: In total, 108 noncaries human third molar teeth embedded in acrylic blocks, grinded from the occlusal surfaces until dentin was exposed, and divided into 9 randomized groups ( n = 12). In total, 108 ceramic samples prepared in disc shape (3mm × 3mm) from IPS e. max CAD (Ivoclar Vivadent) blocks. Four adhesive resin cements: Variolink Esthetic DC (Ivoclar Vivadent), G-CEM LinkForce (GC), Panavia V5 (Kuraray Noritake), Maxcem Elite Chroma (Kerr), and three flowable composites: G-ænial Universal Flo (GC), Herculite XRV Ultra Flow (Kerr), Vertise Flow (Kerr), and one preheated composite: Enamel Plus HRI (Micerium) luted to the prepared occlusal surfaces of the teeth with total-etch, self-etch, and self-adhesive protocols. Then samples were thermocyled (5,000 cycles, 5–55°C, dwell time 20 s). SBS test was performed in a universal testing machine (at 0.5 mm/min). Failure modes were examined under a stereomicroscope at ×25 magnification. Data were analyzed using Kruskal–Wallis and Dunn–Bonferroni tests ( α = 0.05). Results: There were statistically significant differences among material types ( P < .05). Highest SBS values found in G-ænial Universal Flo (15.43 ± 5.67), and the lowest values obtained in Maxcem Elite Choroma (SA) (1.25 ± 1.47). There were no significant differences between self-etch (Panavia V5, Maxcem Elite Choroma [SE]) and self-adhesive (Maxcem Elite Choroma [SA], Vertise Flow) protocols ( P > .05). Conclusion: Flowable composites can be alternatives to resin cements when bonded with total-etch procedures. Bond strength of self-etch and self-adhesive applications is still to be developed.

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.

Polymerization Stress and Gap Formation of Self-adhesive, Bulk-fill and Flowable Composite Resins

Clinical Relevance Bulk-fill materials show a similar or better performance than control flowable materials regarding interfacial integrity. However, some self-adhesive composites need improvements to achieve competitive performance. SUMMARY Objective: This laboratory study compared the polymerization stress and gap formation of self-adhesive, bulk-fill and control flowable composites. The degree of conversion (DC) and post-gel shrinkage were also assessed. Methods: Two self-adhesive (Vertise Flow and Fusio Liquid Dentin), two bulk-fill (Tetric N-Flow Bulk-Fill and Filtek Bulk-Fill Flowable Restorative), and two control flowable (Z350 XT Flowable Restorative and Tetric N-Flow) composites were evaluated. Polymerization stress (PS) was determined in a universal testing machine (n=5). Gap formation was evaluated by scanning electron microscopy in class I restorations (n=6). DC was measured by Fourier transform infrared spectroscopy (n=3). Post-gel volumetric shrinkage (VS) was measured using the strain gauge method (n=5). Data were submitted to one-way analysis of variance or a Kruskal-Wallis test (α=0.05). Results: Vertise Flow and Fusio Liquid Dentin presented the highest interfacial gap (27%±5% and 21%±6%, respectively), which was associated with their highest PS (4.1±0.8 MPa and 3.5±0.6 MPa, respectively) and DC (63%±2% and 60%±2%, respectively) in spite of the lowest VS (1.0%±0.2% and 1.0%±0.3%, respectively). Tetric N-Flow Bulk-Fill and Filtek Bulk-Fill Flowable Restorative presented similar PS (2.9± 0.3 MPa and 2.4±0.2 MPa, respectively) to both control materials. However, the Tetric N-Flow Bulk-Fill showed the lowest gap (7%±2%) and the highest DC (64.3%±0.4%), and the Filtek Bulk-fill presented a marginal gap (17.8%±3.4%) and a DC (54.5%±2.7%) similar to the control materials. The VS values of both bulk-fill materials were similar to those of Tetric N-Flow and lower than that of Z350 XT Flowable Restorative. Conclusions: Bulk-fill composites showed either similar or significantly lower interfacial gaps and PS than the control flowable composites. The self-adhesive composites showed a significantly higher gap percentage and PS than the control and bulk-fill materials.

Microleakage of a Self-Adhesive Flowable Composite, a Self-Adhesive Fissure Sealant and a Conventional Fissure Sealant in Permanent Teeth with/without Saliva Contamination

Objectives: Application of fissure sealants is a practical method for prevention of occlusal pit and fissure caries. Microleakage is an important factor affecting the success of fissure sealant treatment. This study aimed to assess the microleakage of a self-adhesive flowable composite, a self-adhesive fissure sealant and a conventional fissure sealant in permanent teeth with/without saliva contamination. Materials and Methods: This in vitro, experimental study evaluated 108 extracted human third molars, which were randomly divided into six groups (n=18) of control, Denu-Seal conventional fissure sealant applied on etched enamel with/without saliva contamination, Vertise Flow self-adhesive flowable composite applied on rinsed and dried enamel with/without saliva contamination and Prevent Seal self-adhesive fissure sealant applied on rinsed and dried enamel with/without saliva contamination. Microleakage was assessed using the dye penetration technique and subsequent observation of samples under a stereomicroscope. Data were analyzed using the Kruskal-Wallis and Tukey’s test. Results: Microleakage of the conventional fissure sealant with/without saliva contamination was significantly lower than that of other groups (P<0.05). Conclusion: Microleakage of the conventional fissure sealant is less than that of self-adhesive fissure sealant and self-adhesive composite, irrespective of saliva contamination.

Microleakage of a Self-Adhesive Flowable Composite, a Self-Adhesive Fissure Sealant and a Conventional Fissure Sealant in Permanent Teeth with/without Saliva Contamination

Objectives: Application of fissure sealants is a practical method for prevention of occlusal pit and fissure caries. Microleakage is an important factor affecting the success of fissure sealant treatment. This study aimed to assess the microleakage of a self-adhesive flowable composite, a self-adhesive fissure sealant and a conventional fissure sealant in permanent teeth with/without saliva contamination. Materials and Methods: This in vitro, experimental study evaluated 108 extracted human third molars, which were randomly divided into six groups (n=18) of control, Denu-Seal conventional fissure sealant applied on etched enamel with/without saliva contamination, Vertise Flow self-adhesive flowable composite applied on rinsed and dried enamel with/without saliva contamination and Prevent Seal self-adhesive fissure sealant applied on rinsed and dried enamel with/without saliva contamination. Microleakage was assessed using the dye penetration technique and subsequent observation of samples under a stereomicroscope. Data were analyzed using the Kruskal-Wallis and Tukey’s test. Results: Microleakage of the conventional fissure sealant with/without saliva contamination was significantly lower than that of other groups (P<0.05). Conclusion: Microleakage of the conventional fissure sealant is less than that of self-adhesive fissure sealant and self-adhesive composite, irrespective of saliva contamination.