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Purpose: To evaluate the effect of two surface conditioning methods, namely conventional hydrofluoric acid vs self-etching primer, and the application of adhesive on the bond strength of composite cement to CAD/CAM glass-ceramics. Materials and Methods: Blocks (N = 96) (12 x 10 x 2.5 mm) were manufactured, 24 for each tested ceramic type: lithium silicate ceramic (LS), polymer-infiltrated ceramic (PIC), leucite-reinforced feldspathic ceramic (FD), and lithiumdisilicate glass-ceramic (LD). For bond strength testing, 64 blocks were randomly divided into 16 groups (4 blocks per group) according to the following factors: ceramic: 4 levels; etching: 2 levels (HFS: hydrofluoric acid + silane or Monobond Etch & Prime [MEP]); and adhesive application: 2 levels, with (signified as A) and without. Then for each group, 15 composite cement cylinders (AllCem Dual, FGM) were built up. All specimens were subjected to thermocycling (10,000 cycles) and to shear bonding strength testing (SBS) (100 kgf, 0.5 mm/min). Mean shear stresses (MPa) were statistically analyzed by three-way ANOVA, Tukey's test, and Weibull analysis. Results: The mean bond strength of group PIC-HFS-A (28.45 ± 7.6 MPa) was significantly higher than that of groups LS-HFS-A (12.11 ± 2.7 MPa) and FDHFSA (20.86 ± 2.0 MPa). Group PIC-HFS bond strength (25.02 ± 6.5 MPa) was significantly higher only when compared to group LS-HFS (15.82 ± 4.4 MPa). The LS group presented lower SBS compared to all other groups. No significant differences were found between HFS and MEP surface treatments. Conclusion: Surface treatment with MEP promotes adhesion similar to that of HFS. Additional application of adhesive after the surface treatments did not improve the bond strength. [ABSTRACT FROM AUTHOR]

This study evaluated the mechanical behavior and risk of failure of three CAD-CAM crowns repaired with different resin composites through a three-dimensional (3D) finite element analysis. Three-dimensional models of different cusp-repaired (conventional nanohybrid, bulk-fill, and flowable resin composites) crowns made of zirconia, lithium disilicate, and CAD-CAM resin composite were designed, fixed at the cervical level, and loaded in 100 N at the working cusps, including the repaired one. The models were analyzed to determine the Maximum Principal and Maximum Shear stresses (MPa). Complementary, an in vitro shear bond strength test (n = 10) was performed to calculate the risk of failure for each experimental group. The stress distribution among the models was similar when considering the same restorative material. The crown material affected the stress concentration, which was higher for the ceramic models (±9 MPa for shear stress; ±3 MPa for tensile stress) than for the CAD-CAM composite (±7 MPa for shear stress; ±2 MPa for tensile stress). The shear bond strength was higher for the repaired CAD-CAM resin composite (±17 MPa) when compared to the ceramics (below 12 MPa for all groups), while the repair materials showed similar behavior for each substrate. The stress distribution is more homogenous for repaired resin composite crowns, and a flowable direct resin composite seems suitable to repair ceramic crowns with less risk of failure. [ABSTRACT FROM AUTHOR]

Introduction -- Indirect restorations are frequently luted to the remaining tooth structure with new age self-adhesive resin cements. Use of these advanced single step cements reduce chair side time for the clinician. In clinical practice it is not possible to achieve complete isolation in the oral cavity. Contamination during bonding procedures is inevitable, however shorter the time taken to perform the bonding procedure more effective the moisture control by conventional means. This contamination may alter the binding capacity of the cement to the dentine and thus affect the retention of the prosthesis. Aim -- To compare and evaluate the Shear Bond Strength of Two Self adhesive Resin Cements and Dentin with and without salivary fluid contamination. The null hypothesis states that there is no difference exists in the SBS after salivary contamination at the dentine interface. Materials and Method -- 40 freshly extracted premolar teeth were grounded occlusally and embedded in acrylic blocks. The 40 blocks were randomized into 4 groups. Each group was bonded with either resin cement before or after salivary contamination. All samples were tested using the Universal Testing Machine at a cross head speed of 0.5mm/min. The force of dislodging was noted. The data was then subjected to paired and unpaired t test. Results -- On analysis no statistically difference in SBS was noted between A1,B1 and A2,B2. On comparing the groups A1 and A2(after salivary contamination) and B1 and B2(after salivary contamination) p<0.05 was noted which was of statistical significance. Conclusion -Salivary Contamination reduced the SBS between the resin cements and dentin. The individual resin cements showed no statistical difference in shear bond strength. [ABSTRACT FROM AUTHOR]

AIM: To evaluate the shear strength of Orthocem and BracePaste polymerizable cement light‑cured with light‑emitting diode (LED) units with different wavelengths (Bluephase N) with their high power, low power, and soft start programs in the bonding of metal brackets. MATERIALS AND METHODS: In vitro experimental research was performed. Mini Roth 0.022 metal brackets (Roth Orthometric brackets) were used. The adhesives were placed on the metal brackets with Orthocem and BracePaste resin cement. To compare the average strengths, the analysis of variance (ANOVA) test was used (P < 0.05). RESULTS: The average shear strength was better with Bracepaste polymerizable cement compared to Orthocem cement in all its high power, low power, and soft star programs; the highest was Bracepaste with soft start of 26.52 MPa, and the lowest was Orthocem with soft start of 13.92 MPa. When evaluating the differences, it was found that these were statistically significant in all groups (P < 0.05). CONCLUSIONS: Differences were found in the shear strength of light‑curing Orthocem and Bracepaste light‑curing cement cured with LED units with different wavelengths in bonding metal brackets to the tooth in vitro. [ABSTRACT FROM AUTHOR]

Aims: This study aims to evaluate the shear bond strength of three types of dual-cure self-adhesive resin cement (SARCs) bonded to three different substrates with detection types of failure, EDX analysis for substrates, control substrate, and after three resin cement applications. Materials and methods: Thirty specimens from enamel and the same number from dentin and zirconia are prepared. Zirconia discs prepared by CAD-CAM system. Dental specimens prepared from intact surface 3rd molar for enamel and premolar for dentin. After teeth sectioning, all specimens are embedded in auto-cure acrylic resin in a plastic tube. All specimens were polished with sandpaper and zirconia sandblasting, rubber mold was fixed on the surface of the specimen. Three types of dual-cures (SARCs) were applied on the surface of the specimens and after curing the specimens were kept in distilled water at 37 ºC inside the incubator for 24 hours. Then specimens subjected to shear bond strength on a universal test machine after the failure occurs specimens examined under a stereomicroscope to detect the mode of failure. Three control specimens enamel, dentin, and zirconia without any treatment, and nine were from failure specimens send to EDX analysis. Results: The results of this study analyzed with SPSS 25 edition, results showed no significant difference in shear bond strength (SBS) between the three (SARCs) bonds to enamel substrate, while in dentin and zirconia, there was a significant difference in SBS between self-adhesive resin cement. Failure mode detected under the stereomicroscope examination shows no significant difference between the three substrates in failure mode when the bond to BisCem® and TheraCem®Ca, but RelyX™U200 showed a significant difference. EDX analysis shows the presence of Calcium, Phosphorus ions on the zirconia surface when TheraCem®Ca was applied while not present when using the other two types of cement. The amount of calcium and phosphorus ions different from one specimen to another related to the type of substrate and the cement when compare with the control group. Conclusion: TheraCem ®Ca showed improvement in SBS to zirconia due to its composition such as acidic monomer MDP and calcium and phosphorus ions. BisCem and RelyXU200 show better performance with tooth structure and comparable results with zirconia.

Aim: Clinicians and researchers have always made every effort to achieve proper bonding between the surface of the tooth and the rebonded orthodontic brackets in order to prevent the re-fracture failure of orthodontic pressures throughout treatment. The aim of this study was to determine the bond strength of rebonded brackets by four adhesive removal methods.Materials and methods: Seventy-five orthodontic brackets were bonded to the extracted first premolar teeth and then debonded. Fifteen of these teeth were rebonded to new brackets after adhesive removal and were named as the control group. Sixty debonded brackets were divided into four groups by means of resin-removal: laser, burr, sandblast, and direct flame. These recycled brackets were re-bonded to the teeth with the same basic bonding methods. The shear bond strength (SBS) was measured at the speed of 0.5 mm/min and the data were analyzed using ANOVA and post hoc tests (α=0.05).Results: SBS was significantly different in all four groups compared to the control group (p

In recent years, offshore wind power has been developing rapidly, and single piles are among the commonly used foundations for wind turbines. Presently, experimental studies of the grouted connections of pile foundations are limited to the study of scaler models. Numerical simulations are more suitable for the mechanical analysis of the full-size structure instead of experimental ones. In numerical simulations, the linear elasticity model is widely adopted, but the plastic damage is studied scarcely. So, shear bond parameter research concerning grouted joints needs to be supplemented. In this paper, a bilinear random-motion reinforcement model based on the classical metal plasticity theory is adopted for steel, and the model for the grouting material is based on the Sidiroff energy equivalence principle. The plastic damage model for the grouted connecting section is established; the stresses and deformation distribution of the steel pipes and grout in the connecting section are analyzed using the changed shear bond parameters. The results show that the rectangular and triangular shear bonds are more reasonable than the semicircular shear bond transfer. Increasing the height of the shear bond may reduce the maximum stress and the maximum vertical displacement of the grout, and the shear bond width change has less influence on the joint bond stress and displacement. [ABSTRACT FROM AUTHOR]

This study evaluated the mechanical behavior and risk of failure of three CAD-CAM crowns repaired with different resin composites through a three-dimensional (3D) finite element analysis. Three-dimensional models of different cusp-repaired (conventional nanohybrid, bulk-fill, and flowable resin composites) crowns made of zirconia, lithium disilicate, and CAD-CAM resin composite were designed, fixed at the cervical level, and loaded in 100 N at the working cusps, including the repaired one. The models were analyzed to determine the Maximum Principal and Maximum Shear stresses (MPa). Complementary, an in vitro shear bond strength test (n = 10) was performed to calculate the risk of failure for each experimental group. The stress distribution among the models was similar when considering the same restorative material. The crown material affected the stress concentration, which was higher for the ceramic models (±9 MPa for shear stress; ±3 MPa for tensile stress) than for the CAD-CAM composite (±7 MPa for shear stress; ±2 MPa for tensile stress). The shear bond strength was higher for the repaired CAD-CAM resin composite (±17 MPa) when compared to the ceramics (below 12 MPa for all groups), while the repair materials showed similar behavior for each substrate. The stress distribution is more homogenous for repaired resin composite crowns, and a flowable direct resin composite seems suitable to repair ceramic crowns with less risk of failure.

Composite slabs comprised of profiled steel sheets and concrete topping are the most common floor solution in composite building construction. The main advantages of this structural system are expected to be faster construction, removal of standard replaceable shuttering, and a reduction in the number of props required. The profiled steel sheets serve during the construction stage as a formwork instead of the traditional formwork. Later, when the concrete is cured, the profiled steel sheets work as the main reinforcement in the composite slabs. Longitudinal shear bond resistance is an important factor when designing composite slabs. PSC and m-k design approaches are considered the most often utilized methods for determining the shear bond capacity of the composite slabs. Four specimens of composite slabs in simply supported conditions were cast and tested in this study using a four-point bending test. In addition, shear span and thickness effects were studied. In this study, the shear bond capacity of the composite slabs was calculated using the m-k method. The experimental test data used in the linear regression analysis were plotted to predict the m-k values. The structural performance of composite slab specimens was evaluated using failure modes, load-deflection behavior, load-end slip behavior, and horizontal shear bond strength. The results suggested that specimens with greater thickness and shorter shear spans can withstand greater loads than specimens with greater thickness and longer shear spans, which may indicate that slenderness is a critical factor impacting the ultimate capacity of composite slabs. [ABSTRACT FROM AUTHOR]

This paper investigates the possible benefits and difficulties of using composite slabs, consisting of galvanized steel decks and in situ concrete, in reinforced concrete (RC) framed structures. Three different test arrangements were used. A four-point static test (quasi-test) has compared the flexural behavior of the proposed composite slab with traditional solid slab used with a RC beam under gravity load. The m–k values arrangement measures longitudinal shear to evaluate the composite action between the steel deck and the RC slab. The composite action between the RC beam and the composite slab has been examined by using a slip capacity test through four different cases. Results of the quasi-test, showed that both slabs had similar flexural behavior and capacity, while the proposed composite flange had higher total deflection but smaller crack widths than solid concrete flanges. The composite slab's m–k values were found acceptable compared to those in the literature. Longitudinal shear stress with a ductile mode of failure was observed in all specimens. In the slip capacity test, the concrete's shear forces were transferred by the concrete itself since the beam and slabs were monolithic, where no slip between the slabs and the beam was observed. Comparing the proposed composite slab with commonly known slabs (solid concrete one-way, two-way, joist, and flat slabs) emphasizes the proposed slab's ability to reduce the overall weight with the same load-carrying capacity, while speeding up the construction process. [ABSTRACT FROM AUTHOR]

This paper investigates the structural performance of a new two-way profiled steel decking system for steel-concrete composite slabs. Several studies have investigated steel decking for steel-concrete composite slabs and focused on utilising the conventional deck as a one-way floor system. The newly developed deck consists of top-hat sections formed by bending corrugated sheets at 90°, which are attached to a corrugated base sheet. The deck is designed for improved composite and two-way action contributed by its unique geometry due to corrugations in the transverse and longitudinal directions. This paper experimentally tested a novel steel decking geometry under construction stage loading. It was in the absence of concrete to establish the deck's suitability for construction and contribution towards loading capacity and performance for future use as a two-way composite slab. Ultimate load, two-way action, and failure modes were identified. A finite element model was also developed, and parameters assessed that could influence the performance when the deck is potentially used in the composite stage. It was concluded that, while increasing the thickness of the corrugated base sheet significantly affects the load-carrying capacity, the thickness of the top hats has no significant impact. Improved load transfer with two-way behaviour is observed when the bottom flanges of the top hats are continuously connected to the bottom flanges of the adjacent top hats to form a deck. This contrasts with the concept deck, where individual top hats are attached to a corrugated base sheet. In this case, decks with a corrugated base sheet perform 54% better in ultimate load capacity than decks without a corrugated base sheet. [ABSTRACT FROM AUTHOR]

Background: Bonding is an integral part of orthodontic treatment. Orthodontic bonding could be accomplished without the use of primer, it might be possible to reduce the risk of occupational exposure to primer and will save time. So it is very important to know whether primer is required or not. Aim: The aim of this study is to evaluate and compare the shear bond strength (SBS) of metallic and ceramic brackets bonded with and without primer application and to check for residual adhesive post debonding. Material and Method: A total of 100 extracted human premolar teeth were divided into 2 main groups A and B which were further subdivided into: Group A1 - metallic brackets bonded with primer; Group A2 - ceramic brackets bonded with primer; Group B1 - metallic brackets bonded without primer; group B2 - ceramic brackets bonded without primer. The SBS of these brackets was measured. Result: The SBS of group A2 was significantly higher than the other groups, group A1 was the second highest, group B3 was the third highest and group B4 was the least significant. The adhesive remnant index was lowest on failure of ceramic brackets bonded with primer. Conclusion: SBS of ceramic brackets bonded without primer is superior to SBS of metallic bracket bonded without primer and metallic brackets bonded with primer was superior than metallic bonded without primer. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of five porcelain repair systems on shear bond strength in composite and zirconia infrastructures and to identify the bond failure mode after thermocycling. Materials and Methods Disk-shaped zirconia samples (n=50) were divided into five groups (n=10) according to repairing system type. Each repair system was applied to the zirconium samples and a hybrid composite was used for repairing. Shear bond testing of all groups was carried out using a universal testing machine after thermocycling. Results Repair systems demonstrated no significant difference in repairing zirconia except Single Bond. Single Bond was the weakest in repairing the infrastructures. The highest and lowest mean bond strength values for the zirconia groups were 18,91 MPa and 3,63 MPa, respectively. Conclusion The three repair systems, Ivoclar, Clearfil, and Bisco, were more effective than the Single Bond and Ultradent repair systems in repairing zirconia, and their bond failure modes were both mixed and adhesive. [ABSTRACT FROM AUTHOR]

Introduction: The bond strength can be described as the most well-known success factor in layered all-ceramic crowns whereas the most common failure reason in the core-veneer interface is delaminating. This study aims at investigating the impact of various particle sizes of sandblasting on the roughness of the heat press (lithium di-silicate) core and shear bond strength between veneering ceramic and lithium disilicate core. Methods: Forty ceramic samples were divided into 4 types of surface treatments groups; 10without treatment (Control), the other 3 groups were treated by 50 µm AL2O3, 150 µm AL2O3, and 250 µm AL2O3 air borne particle abrasion respectively. The estimation of the roughness (nm) was made before and after treatment. Shear bond strength (MPa) and the mode of failure test was performed for all groups. In order for the data to be analyzed, a one-way ANOVA test and (LSD Test) were made for that purpose. Results:Sandblast group with 250µm AL2O3 had superior roughness and shear bond strength value, followed by the group treated with150µm AL2O3, the roughness of the group treated with50µm AL2O3 lower than 150µm AL2O3 and 250µm AL2O3. The control and sandblast with 50µm AL2O3 groups showing the same mean value in shear bond strength. Conclusion: Surface roughness and shear bond strength increased in group sandblast with 250µm AL2O3.The adhesive mode of failure was produced in (control, sandblast with 50 µm AL2O3) groups. The cohesive failure in (lithium di-silicate) core specimens produced in (sandblast with 250 µm AL2O3 and sandblast with 150 µm AL2O3) groups. [ABSTRACT FROM AUTHOR]

Aim: To analyze the influence of different surface pretreatments of zirconium dioxide reinforced lithium disilicate ceramics on the shear bond strength of self-adhesive resin cement. Materials and methods: Eighty-four zirconium reinforced lithium disilicate disc Vita suprinity (Vita Zahnfabrick, Bad Säckingen, Germany) 14x12x2 mm specimens were fabricated according to the manufacturer’s recommendations. The specimens were embedded in acrylic resin blocks and randomly divided in seven groups (n=12/each) accorrding to the treatment: Group 1- 10% hydrofluoric acid; Group 2- silane; Group 3- hydrofluoric and silane; Group 4- sandblasting with silane; Group 5- Er: YAG laser+ silane; Group 6- Nd: YAG laser + silane; and the control group, in which the specimens were not treated. Round shape composite discs (Filtek Bulk fill, 3M ESPE, St.Paul, Minnesota, USA) with 3.5 mm diameter, were made for shear bond strength testing, and then cemented to the ceramic sample surface using composite cement (RelyX U200 Automix, 3M ESPE, Neuss, Germany). After cementing the composite disc on the sample, the samples were subjected to shear bond strength test of 10 N with a “stress rate” of 1 MPa / s. To determine the nature of the fracture (adhesive, cohesive or adhesivecohesive), the broken samples were examined under a stereomicroscope. The ANOVA test and the Tukey test were used to compare the values of the bond strength characteristics between different types of materials. All tests were performed with a significance level of α = 0.05. Results: There was a significant difference in the shear bond strength of self-adhesive cement to dental lithium-disilicate ceramics reinforced with zirconium dioxide after different preparation protocols (p

Introduction: Intraoral repair has been suggested as a treatment option to repair the chipping or fracture of veneered zirconia; the success of the procedure is mainly determined by the bonding between zirconia and composite resin. The present study aimed to investigate and compare the shear bond strength (SBS) of two intraoral repair systems to zirconia ceramic treated with a laser or air-abrasion surface modification. Methods: Ninety tube-shaped samples (diameter of 10 mm and height of 4 mm) were divided into three main groups: Group I (zirconia 100%, n = 30); Group II (veneer ceramic 100% n = 30); Group III (zirconia with a veneer ceramic n = 30). Each main group was subdivided into two subgroups (n = 15): Subgroup A: samples repaired with Ceramic Repair N; Subgroup B: samples repaired with the Cimara Repair System. The subgroup samples were further subdivided based on the treated surface (n = 5 samples): Control (no surface modification), Er,Cr:YSGG laser surface modification, and air-abrasion surface modification. The SBS was employed using a universal testing machine. The mode of failure was observed using a stereomicroscope. Results: Significant differences were observed in the mean SBS values between the different surface modifications (P 0.05). Tukey's post hoc test showed that the air-abrasion surface modification of the veneer ceramic repaired with the Ceramic repair N system had the highest mean value (13.74 MPa) among the different groups, while no surface modification of zirconia repaired with the Cimara repair system had the lowest mean value (2.84 MPa). The control group (no surface modification) had the lowest mean value among all the treated groups. Conclusion: The SBS is surface modification-dependent, and higher SBS is obtained by air-abrasion than Er, Cr:YSGG laser surface modifications with the selected parameters. The Ceramic repair N system had significantly higher SBS for all surface-treated substrates than the Cimara repair system. [ABSTRACT FROM AUTHOR]

In recent years, offshore wind power has been developing rapidly, and single piles are among the commonly used foundations for wind turbines. Presently, experimental studies of the grouted connections of pile foundations are limited to the study of scaler models. Numerical simulations are more suitable for the mechanical analysis of the full-size structure instead of experimental ones. In numerical simulations, the linear elasticity model is widely adopted, but the plastic damage is studied scarcely. So, shear bond parameter research concerning grouted joints needs to be supplemented. In this paper, a bilinear random-motion reinforcement model based on the classical metal plasticity theory is adopted for steel, and the model for the grouting material is based on the Sidiroff energy equivalence principle. The plastic damage model for the grouted connecting section is established; the stresses and deformation distribution of the steel pipes and grout in the connecting section are analyzed using the changed shear bond parameters. The results show that the rectangular and triangular shear bonds are more reasonable than the semicircular shear bond transfer. Increasing the height of the shear bond may reduce the maximum stress and the maximum vertical displacement of the grout, and the shear bond width change has less influence on the joint bond stress and displacement.

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This paper investigates the structural performance of a new two-way profiled steel decking system for steel-concrete composite slabs. Several studies have investigated steel decking for steel-concrete composite slabs and focused on utilising the conventional deck as a one-way floor system. The newly developed deck consists of top-hat sections formed by bending corrugated sheets at 90°, which are attached to a corrugated base sheet. The deck is designed for improved composite and two-way action contributed by its unique geometry due to corrugations in the transverse and longitudinal directions. This paper experimentally tested a novel steel decking geometry under construction stage loading. It was in the absence of concrete to establish the deck’s suitability for construction and contribution towards loading capacity and performance for future use as a two-way composite slab. Ultimate load, two-way action, and failure modes were identified. A finite element model was also developed, and parameters assessed that could influence the performance when the deck is potentially used in the composite stage. It was concluded that, while increasing the thickness of the corrugated base sheet significantly affects the load-carrying capacity, the thickness of the top hats has no significant impact. Improved load transfer with two-way behaviour is observed when the bottom flanges of the top hats are continuously connected to the bottom flanges of the adjacent top hats to form a deck. This contrasts with the concept deck, where individual top hats are attached to a corrugated base sheet. In this case, decks with a corrugated base sheet perform 54% better in ultimate load capacity than decks without a corrugated base sheet.

Semi-precast-reinforced concrete slab system offers more economic method of construction as it minimises the need of formwork at site. The assembly of semi-precast slab system involves two steps: (1) casting of semi-precast slab at the yard and (2) overtopping of concrete at the site. One of the main factors that influence the performance of such slab system is the interface bonding between precast and overtopping concrete. Therefore, in order to better understand the performance of this slab system, a research was carried out to investigate the influence of surface treatment methodologies to the overall flexural behaviour through experimental and numerical studies. In total, five representative semi-precast slabs were constructed and tested to assess the flexural performance with different surface preparation methods and concrete overtopping. Further small-scale precast with overtopped concrete couplets and triplets were casted and tested as the representative semi-precast concrete slab types to examine the interface shear and tensile bond strength characteristics with those different surface treatments. The experimental results revealed that the surface treatment methods have influenced the flexural behaviour of the slabs, where the interface shear bond strength exceeds more than 1.0 MPa and the slab system behaves monolithically under flexural action. Moreover, numerical modelling technique for this slab system was developed based on the finite element framework to further analyse the overall flexural behaviour. Subsequently, good agreements between experimental and developed numerical model results were found. Finally, parametric analyses were performed to further assess the influences of concrete strengths, spans and reinforcement ratios on the safe imposed pressure applicable for this slab system. [ABSTRACT FROM AUTHOR]

One of the causes of dental caries that occurs due to orthodontic treatment is the lack of antibacterial properties in orthodontic adhesive. This study was designated to investigate the effect of orthodontic resin modified by incorporating Nano Cinnamon powder on the shear bond strength of orthodontic brackets. Heliosit Orthodontic Resin, a photo-activated light cure resin was modified by the addition of Cinnamon in the form of Nano particle powder. Twenty uniform disks were made, 5 as a control and 5 for each concentration of the 1%, 3% and 5% wt/wt Cinnamon modified resin. Their antimicrobial activity against Streptococcus Mutans was tested using the disk diffusion method. Then, the most effective concentration of the modified resin was used to bond metal orthodontic brackets to human extracted premolars. The universal testing machine was used to record the shear bond strength of the control and the modified resin. Also, the adhesive remnant index was measured. Disc diffusion method showed that the 3% wt/wt Cinnamon powder modified resin was more effective than 1% with a larger bacterial inhibition zone. Shear bond strengths of the control were 8.50 MPa and 7.20 MPa for the 3% Cinnamon modified resin with no significant difference between them. Also, no significant difference was recorded in the adhesive remnant index scores between the control and the modified resin groups. Findings of this study revealed that the incorporation of 3% Cinnamon Nano particles in orthodontic resin produced an antibacterial effect against Streptococcus mutans without compromising the shear bond strength. Incorporation of Cinnamon Nano particles in orthodontic resin may reduce caries formation around brackets during treatment course. [ABSTRACT FROM AUTHOR]

Purpose: This study was conducted to investigate the surface effects on dentin following laser "etching" with an Nd:YAG laser, and to determine the shear bond strengths of composite to untreated and laser-treated dentin. Materials and Methods: Dentin surfaces from freshly extracted permanent molars were subjected to laser treatment with an Nd:YAG laser. The results were analyzed using an SPSS/PC multiple range test. The shear bond strengths of laser-treated dentin/composite and untreated dentin/composite by dentin bonding were also determined. These results were also compared using the SPSS/PC multiple range test. Results: Shear bond strength in laser and acid groups were 6.70 ± 2.86 and 15.24 ± 8.51 MPa, respectively. Bond strength in the laser group was significantly lower than in the other group (p < 0.01). Conclusion: The Nd:YAG dental laser tested produced weaker shear bond strength than conventional acid etching. [ABSTRACT FROM AUTHOR]

Purpose: To examine the effect of different adhesive luting systems on the shear bond strength of all-ceramic restorations to dentin surfaces. Materials and Methods: Forty-eight all-ceramic disks (2 x 3 mm; IPS e.max Press) were fabricated. Forty-eight noncarious extracted human molars were divided into 4 groups. In groups 1 to 4, IPS e.max Press disks were luted with Variolink 2/Excite DSC (etch-and-rinse), Clearfil Esthetic Cement/Clearfil Protect Bond (antibacterial and self-etching), Multilink/Multilink Primer (self-etching), or Multilink Sprint (self-adhesive). All specimens were subjected to 5000 thermocycles (5°C to 55°C, 30-s dwell time). Shear bond strengths were tested using a universal testing machine until failure. The analysis of the fractured dentin surfaces was performed using an optical microscope at 10X and 1000X magnification; the images were analyzed with an image analyzer. Data were analyzed with one-way ANOVA and Tukey's test at a significance level of p < 0.05. Results: Mean shear bond strength data of the groups in MPa were: Variolink 2/Excite DSC: 25.89 ± 3.71; Clearfil Esthetic Cement/Clearfil Protect Bond: 17.21 ± 2.71; Multilink/Multilink Primer: 11.6 ± 3.51; Multilink Sprint: 10.4 ± 3.15. According to the one-way ANOVA, there were significant differences in shear bond strength (p < 0.001). According to Tukey's test, statistically significant differences were observed in shear bond strength between groups 1 and 2 (p < 0.001), groups 1 and 3 (p < 0.001), groups 1 and 4 (p < 0.001), groups 2 and 3 (p = 0.003), and groups 2 and 4 (p < 0.001). Conclusion: The etch-and-rinse dentin bonding system produced higher bond strengths of all-ceramics to dentin surfaces than did the self-etching bonding systems and self-adhesive luting system. [ABSTRACT FROM AUTHOR]

• Formation of shear bond layer during FSAM of copper is analyzed. • Effects of shear bond layer on mechanical properties of FSAMed copper is evaluated. • Effects of shear bond layer on fracture morphology of FSAMed copper is evaluated. This study investigates the influence of the shear bond in friction stir additive manufacturing (FSAM) on the quality of printed copper sample. The shear bond is a mixture of thermo-mechanical affected zone (TMAZ) and re-heat affected zone (RAZ), formed around the ultra-fine grain region during FSAM. The shear bond is plays a crucial role in modifying the microstructure and mechanical properties of the printed layers. It is demonstrated that the presence of the shear layer enhances material strength, ductility, and fracture resistance, leading to improved overall quality of the printed samples. The microstructure size of the shear bond is 67.5% smaller than that of copper. This distinctive layer contributes to a notable 20% enhancement in the FSAM sample's performance. [ABSTRACT FROM AUTHOR]

Highlights • Finite element (FE) modeling of profiled steel composite slab with engineered cementitious composite (ECC) • Develop FE models using test results for novel ECC and self-consolidating concrete (SCC) slabs. • Parametric simulations by varying material/geometric and numeric parameters. Abstract This paper presents nonlinear finite element (FE) modeling of composite slab system comprising of profiled steel deck and high performance concrete namely, Engineered Cementitious Composite (ECC) and Self-Consolidating Concrete (SCC). FE models were developed and their performance validated based on experimental results of composite slabs subjected monotonic loading to failure. Parametric studies were conducted to investigate the influence of numerical/material/geometric parameters (such as mesh size, loading constraints, strain increment factor, steel sheet-concrete interaction contact types, concrete types, total/shear span length etc.) on FE model performance. Developed FE models were used to determine behavior of twenty two experimental composite slabs in validation and further validation with performance evaluation stages. The simulated load-deflection response, strength and shear bond capacity of FE model slabs were found to be in good agreement with those obtained from their experimental counterparts. [ABSTRACT FROM AUTHOR]