Shear Bond Strength Research Articles

Antifungal Ability of Novel Silane on Titanium Implant Surface

Titanium and its alloys are commonly used in dentistry for implants due to their strength, lightweight nature, durability, corrosion resistance, and biocompatibility. These implants can osseointegrate after surface treatments such as SLA, plasma-spray, and nanotubes, providing a stable foundation for prostheses. However, Candida albicans, an opportunistic fungal pathogen, can threaten the success of titanium dental implants, causing oral infections in vulnerable individuals. A dual novel silane blend of 3-acryloxypropyltrimethoxysilane (ACPS) and bis-1,2-(triethoxysilyl)ethane (BTSE) has been shown to improve the shear bond strength in resin cement bonds with titanium and ceramics. This study evaluated the effects of Candida albicans colonization on blended silane-coated SLA-Ti surfaces compared to non-coated SLA-Ti (positive control) and flat titanium (negative control). Candida albicans biofilms were cultured on all surfaces, and it was found that silane-coated SLA-Ti had significantly lower CFU counts than non-coated SLA-Ti. However, no significant differences were observed in the RT-PCR results. In conclusion, a combination of 1.0 vol% ACPS and 0.3 vol% BTSE shows promise as a silane coupling agent with potential antifungal properties for inhibiting Candida albicans proliferation.

The effect of addition of Bioglass 45S5 to orthodontic adhesive on shear bond strength of metal orthodontic brackets, An in vitro study

Aim: This study aimed to evaluate the effect of incorporating Bioglass (BG) 45S5 into an orthodontic adhesive on the shear bond strength (SBS) of metal orthodontic brackets bonded to enamel and the adhesive remnant index (ARI) score. Methods: In this in vitro study, 55 extracted sound premolars were randomly divided into five groups (n=11 each). Metal brackets were bonded using Ambar FGM orthodontic adhesive without BG (control group) and with BG 45S5 added at concentrations of 5%, 10%, 15%, and 20% by weight in groups 2 to 5, respectively. The SBS was measured using a universal testing machine, and the ARI score was determined under a stereomicroscope at ×10 magnification. Data were analyzed using one-way ANOVA at a significance level of α=0.05. Results: The highest mean SBS was observed in the 20% BG Group (48.28±24.5 MPa), followed by the control group (35.81±11.11 MPa), 15% BG Group (19.64±5.42 MPa), 10% BG Group (16.3±9.33 MPa), and 5% BG Group (14.21±4.23 MPa). The SBS in the 20% BG Group was significantly higher than in the control (P=0.013), 5% BG (P=0.000), and 10% BG (P=0.002) groups. No significant differences were found in ARI scores among the groups (P=0.810). Conclusion: Adding BG 45S5 to the orthodontic adhesive at concentrations of 5%, 10%, and 15% did not significantly affect the SBS, but a 20% concentration increased the SBS. Incorporating BG at these levels does not adversely impact the SBS or ARI scores.

Development of engineered polymeric reinforced cementitious composite (EPRC) using nature-inspired hollow architectures: Flexural experimental and numerical evaluations

This study explores the integration of nature-inspired architectural designs into Mechanics of Materials (MoM)-based reinforcement layouts for reinforced cementitious composites (RCs). While traditional MoM layouts focus on longitudinal rebars for tensile strength, this study aims to enhance the flexural properties of RCs by incorporating nature-inspired elements like hollow tubes found in plant stems. The research utilizes both experimental and numerical methods to evaluate the flexural performance of engineered polymeric reinforced cementitious composites (EPRCs) with integrated nature-inspired motifs. A numerical model, based on the material properties of reinforcing elements and the cementitious matrix, was developed to simulate the flexural performance of EPRCs reinforced with both solid and hollow bars, including MoM-based solid and hollow rebars. The model's predictions were validated through experimental testing of 3D-printed MoM-based solid and hollow rebars under three-point bending conditions. The results demonstrated that EPRCs reinforced with hollow rebars exhibited significantly improved flexural properties compared to those with solid rebars. Specifically, the hollow-reinforced samples achieved an average modulus of rupture of 8.68 MPa, toughness of 11.76 N m, and mid-point deflection of 1.99 mm, representing increases of 34 %, 55 %, and 93 %, respectively, over their solid counterparts. These enhancements are attributed to improved shear reinforcement and bond strength despite the reduced moment of inertia of the hollow rebars. The study provides valuable insights for optimizing the mechanical properties of RCs in civil engineering applications through the incorporation of nature-inspired architectural designs.

Experimental and Chitosan-Infused Adhesive with Dentin Pretreated with Femtosecond Laser, Methylene Blue-Activated Low-Level Laser, and Phosphoric Acid.

Aim: To prepare experimental adhesive (EA) with 1% and without chitosan nanoparticles on dentin conditioned with a conventional technique phosphoric acid (PA) compared with two different contemporary techniques: photodynamic therapy (PDT) and femtosecond laser (FSL). Method: The methodology consisted of synthesis of EA and 1% chitosan-modified adhesive (CMA). Scanning electron microscopy, dentin adhesive interface assessment, energy-dispersive spectroscopy, shear bond strength (SBS), degree of conversion (DC), and bond failure were assessed. Teeth were selected, disinfected, and mounted in acrylic up to the cementoenamel junction. Occlusal enamel was removed and teeth were randomly allocated into groups and conditioned. These included Group 1: samples treated with PA; Group 2: specimens conditioned with methylene blue photosensitizer (MBP) activated by PDT; and Group 3: samples conditioned with FSL. Following different conditioning regimes, specimens were bonded using 1% CMA and EA. The composite buildup was followed by SBS testing and a bond failure assessment. DC was assessed for both EA and CMA. Analysis of variance and Tukey's post hoc test were used to compare the mean and standard deviation of SBS and DC in different experimental groups, with a significance level of p < 0.05. Results: Dentin pretreated with etch and rinse demonstrated the highest bond strength with 1% CMA. Dentin conditioned with MBP activated by PDT and bonded to EA showed the lowest bond scores. Overall SBS values of 1% CMA were better than EA irrespective of the conditioning regime of dentin. The DC was higher in EA adhesive. This was followed by DC in 1% CMA. DC in EA was found to be comparable with 1% CMA. Conclusions: PA remains the gold standard for dentin conditioning. The incorporation of 1% chitosan in adhesive improves SBS and results in no change in DC. The use of FSL in dentin conditioning can be used as an alternative approach as it results in SBS within acceptable limits. The study was approved by the ethical board of King Saud University.

Shear Bond Strength of Five Different Repair Systems to Three Different Ceramic Materials.

The purpose of the current study was to investigate the shear bond strength of composite resin in five different ceramic repair systems for three different ceramic materials. 225 monolithic zirconia (Zr) and lithium disilicate (LDS) and cobalt chromium (CoCr) specimens with feldspathic porcelain (FP) veneer were fabricated (N=75 per material). The specimens underwent thermo-cycling and were randomly divided into five groups for the following intra-oral repair systems (n=15): 1) Clearfil Ceramic Primer Plus, Kuraray Noritake, Japan; 2) Ibond Intraoral Repair Kit, Kulzer, Germany; 3) VOCO Cimara, VOCO GmbH Germany; 4) Ivoclar Vivadent, Ceramic Repair System Kit, IvoclarVivadent, Liechtenstein; 5) Ultradent Porcelain Repair Kit, Ultradent Products Inc, USA. After surface conditioning, composite was applied using a cylindrical mold and a second round of thermocycling was performed. Each specimen was then subjected to shear load until failure. Microshear bond strength was compared using analysis of variance (one-way ANOVA, Tukey's test, a <0.05). Type of porcelain repair kit significantly affected the shear bond strength. For Zr, the repair systems from Kulzer and VOCO had significantly higher shear bond strength than the other systems (p<0.001) without significant difference between Kulzer and VOCO. For the LDS and CoCr with FP, hydrofluoric acid had the highest shear bond strength (p<0.001). For zirconia, a 10-Methacryloyloxydecyl dihydrogen phosphate (10-MDP) system should be used. The results also suggest that a cleaning bur may be beneficial. For glass-based ceramics and feldspathic porcelain, etching with hydrofluoric acid remains the product of choice.

Effects of Time-Elapsed Bleaching on the Surface and Mechanical Properties of Dentin Substrate Using Hydrogen Peroxide-Free Nanohydroxyapatite Gel.

There is a critical need to address concerns surrounding the potential impact of bleaching gels specifically on the tooth substrate. Therefore, this laboratory investigation aimed to assess the impact of a hydrogen peroxide (HP)-free bleaching (HiSmileTM) in comparison to an HP-based bleaching (Opalescence RegularTM) on the surface and mechanical characteristics of tooth substrate. Sixty sound human premolar teeth were sectioned to produce dentin fragments and divided into two primary groups based on the bleaching agent used. Each group was subdivided into three subgroups (n = 10) per distinct bleaching regimens: (T1) fragments underwent a 7-day immersion in distilled water at 37°C without any bleaching treatment, (T2) fragments underwent a 7-day immersion in distilled water at 37°C, with the application of bleaching gel occurring on the seventh day for 10minutes, and (T3) fragments underwent a bleaching regimen for seven consecutive days, each session lasting for 10minutes. The initial and final evaluations of surface roughness, nano-hardness, and elastic modulus were performed. Following the bleaching regimens of T3, a composite stub was fabricated on the dentin fragments for the shear bond strength (SBS) test. Statistical testing was accomplished using the analysis of variance (P < 0.05). HP-based bleaching gel showed significant differences between measurement intervals in surface roughness, elastic modulus, and SBS parameters (P < 0.05). In contrast, HP-free bleaching gel showed insignificant differences within the group (P > 0.05). The SBS between dentin-composite was significantly affected with the use of HP-based bleaching gel, while HP-free bleaching gel showed insignificant difference between measurement intervals. The qualitative validation of the treatment's impact was further demonstrated using the scanning electron microscopy. The findings suggest that the bonding stability of composite restorations to dentin may be compromised after bleaching with an HP-based gel, whereas immediate bonding procedures can be safely conducted following the application of an HP-free bleaching gel.

3D-Printed One-piece Versus Two-piece Orthodontic Clear Aligner Attachments Bonded with Provisional Crowns: A Proof of Concept

ObjectivesThis study aimed to introduce a novel technique for fabricating provisional crowns integrated as a single unit with aligner attachments. MethodsA total of 60 crowns with attachments were prepared: 20 conventional (Protemp) and 40 3D-printed (20 bonded with attachments; 20 integrated with composite attachments as a single unit) using NextDent resin. Two central incisors were scanned (once without attachments and once with attachments) to create STL files for specimen printing. Half of the specimens (30, n=10 per group) underwent thermal cycling (5000 cycles). Shear bond strengths (MPa) were evaluated using a universal testing machine. The debonded areas and attachment failures were analyzed to determine the fracture type. Data analyses were performed using ANOVA and post hoc Tukey tests (α = .05). ResultsThe 3D-printed specimens showed higher strength values than the bonded attachments per group (P <0.001). The 3D-printed crowns with attachments demonstrated the highest strength (12.39±1.92 MPa). Thermal cycling significantly decreased the bond strength of the attachments (P <0.001), except in the 3D-printed crowns with composite attachments as a single unit, which showed no significant change after thermal cycling (P=0.643). In the bonded attachment groups, the adhesive type was the predominant failure mode, while in the 3D-printed groups, attachment fractures were the primary cause of failure. ConclusionThe 3D-printed provisional crowns with attachments have high strength and is clinically appropriate for orthodontic treatment when temporization of teeth is indicated. Clinical SignificanceThe developed technique for fabricating 3D-printed provisional restorations with orthodontics attachments as a single unit is a promising approach. The technique may be incorporated into the digital orthodontic treatment workflow when temporization is indicated.

Influence of Diode and Nd:YAG laser irradiation on shear bond strength between soft relining material and conventional, thermoplastic, and CAD/CAM denture resins

Influence of Diode and Nd:YAG laser irradiation on shear bond strength between soft relining material and conventional, thermoplastic, and CAD/CAM denture resins

The effect of different enamel surface treatment methods on the shear bond strength between self-adhesive resin composite and orthodontic brackets

The effect of different enamel surface treatment methods on the shear bond strength between self-adhesive resin composite and orthodontic brackets

Laboratory Evaluation of Shear Bond Strength of Self-Adhesive Bulk Fill Composite in Comparison with Bulk Fill Composite.

Laboratory Evaluation of Shear Bond Strength of Self-Adhesive Bulk Fill Composite in Comparison with Bulk Fill Composite.

Surface Roughness and Shear Bond Strength of Nanographene-Reinforced Polymethylmethacrylate

Surface Roughness and Shear Bond Strength of Nanographene-Reinforced Polymethylmethacrylate

Effect of bioactive cement versus MDP-containing resin cement on shear bond strength of super high translucent zirconia to dentin (an in-vitro study)

Effect of bioactive cement versus MDP-containing resin cement on shear bond strength of super high translucent zirconia to dentin (an in-vitro study)

Shear-Bond Strength of Bioactive Restorative Materials to Radiotherapy-Treated Dentin

Shear-Bond Strength of Bioactive Restorative Materials to Radiotherapy-Treated Dentin

Shear-Bond Strength of Composite Resins Repaired with Injectable Composite

Shear-Bond Strength of Composite Resins Repaired with Injectable Composite

COMPARATIVE EVALUATION OF SHEAR BOND STRENGTH OF TWO DIFFERENT RESIN CEMENT TO ZIRCONIA AFTER SURFACE TREATMENT USING ER:YAG LASER: AN IN VITRO STUDY

Zirconia (ZrO2), a crystalline dioxide of zirconium, boasts metal-like mechanical properties and a tooth-like color. Creating a ZrO2 core for prosthetic restorations necessitates a CAD/CAM system adept at handling zirconia. Resin-bonded luting is the top choice for zirconia ceramic restorations, with tribochemical treatment preferred for surface preparation before resin cement luting. Clinical trials indicate that resin cementation improves adhesion and mechanical properties of zirconia restorations. While studies on sandblastings effect on shear bond strength to zirconia exist, more data is needed on the impact of sandblasting and laser treatment on yttria-stabilized tetragonal zirconia. This study examines the shear bond strength of two resin cements to zirconia after Er:YAG laser treatment.

Evaluation of Microleakage and Shear Bond Strength of Two Different Calcium-based Silicate Indirect Pulp Capping Agents When Restored with Glass Ionomer Cement and Composite Resin Restoration: A Comparative In Vitro Study

Evaluation of Microleakage and Shear Bond Strength of Two Different Calcium-based Silicate Indirect Pulp Capping Agents When Restored with Glass Ionomer Cement and Composite Resin Restoration: A Comparative In Vitro Study

Comparative Evaluation of the Shear Bond Strength and Color Stability of Two Commercially Available Intraoral Porcelain Repair Systems: An In Vitro Study

Comparative Evaluation of the Shear Bond Strength and Color Stability of Two Commercially Available Intraoral Porcelain Repair Systems: An In Vitro Study

Evaluation of Etching Time Effect on Shear Bond Strength of Orthodontic Brackets Bonded with Self-Adhesive Composite: An in-Vitro Study

Introduction: Precise acid etching of the tooth surface is a significant factor in the strength of the bracket bond. The current study aimed to determine the effect of different application times of acid etching on the shear bond strength of metallic orthodontic brackets under controlled laboratory conditions. Methods: Sixty intact premolar teeth were selected for this in-vitro study. The samples were divided into four groups based on the different acid etching times: 20, 25, 30, and 35 seconds. The teeth surfaces were etched with 37% phosphoric acid according to the specified times, and brackets were bonded to the enamel surface using GC Ortho connect composite. Shear bond strength values of the brackets was measured using a Universal Testing Machine. The amount of Adhesive Remnant Index was also observed using a stereomicroscope. Additionally, the surface roughness of the tooth enamel after bracket bonding was examined using SEM. The results related to shear bond strength were analyzed with one-way ANOVA statistical test and using SPSS version 16 software. The non-parametric Kruskal Wallis (Wallis-Kruskal) test was also used to check the frequency of ARI index. Results: The highest shear bond strength was observed at 25 seconds, and the lowest at 30 seconds. However, there was no significant difference in the shear bond strength of brackets was observed among the four groups (p=0.186). The highest ARI score was observed at 35 seconds, and the lowest at 20 seconds. No statistically significant difference was observed in the ARI scores in different groups. SEM images revealed that the enamel surface porosity was highest at 20 seconds. Conclusion: The results indicate that the shear bond strength and ARI at different acid etching times do not significantly differ. Therefore, orthodontic bracket bonding can be performed with less acid etching time.

Enhancing Shear Bond Strength in Lithium Silicate Glass Ceramics: Surface Treatment Optimization for Reseating Protocols

The rapid evolution of lithium silicate-based glass ceramics in the field of dental ceramics has led to the availability of different compositions in the market. This in vitro study was conducted to assess an effective protocol for recementing de-bonded lithium silicate-based glass ceramics by evaluating the shear bond strength of three reseating methods. The study included IPS e.max® CAD, Vita Suprinity®, Celtra Duo®, and n!ce as lithium-based glass ceramics. The samples underwent a series of preparation steps, including embedding in acrylic resin, hand polishing, etching with 5% hydrofluoric acid, and application of universal primer and adhesive as per manufacturer instructions. Subsequently, adhesive resin cement was applied to the ceramic tablets, and shear bond strength was assessed using a standardized method. The findings revealed that no single method demonstrated significantly superior results compared to the others. However, it was observed that etching with 5% hydrofluoric acid for 20 s yielded favorable outcomes in terms of time efficiency and standardized results. Additionally, it was noted that although sandblasting increased surface area, it did not enhance bond strength due to unfavorable surface disturbance. In conclusion, the study suggests that etching with 5% hydrofluoric acid for 20 s is a favorable protocol for reseating de-bonded lithium disilicate-based glass ceramics, offering both time efficiency and consistent results for clinicians.

Frictional pull-out work capacity of macro-SSF in concrete composites and evaluation of matrix deterioration due to kinematic fiber-end-slip after full-debonding point

ABSTRACT This paper presents a parametric study on the effect of frictional pull-out work capacity on the performance of fiber/matrix regime during the kinematic pull-out process. This study involves an experimental program of pull-out test of straight steel fiber embedded in concrete composites, numerical study based on finite element modeling, and theoretical approaches based on mathematical model. Various parameters were considered such as fiber geometry, Poisson’s ratio, elasticity modulus, and aspect ratio. The experimental results were calibrated with the results of numerical study, and the theoretical approaches were controlled using deterioration coefficient based on a given curve of uniaxial stress–displacement relationship plotted experimentally. The results showed that the capacity of pull-out work decreases 62.6% when the fiber diameter decreases 6 times. Decreasing the fiber diameter also improves the resistance of the matrix against deterioration. While decreasing the fiber embedded length by 1.8 times, the frictional pull-out work decreases by 56.3% and boosts relatively the resistance of matrix against crumbling, where the frictional shear bond strength improved by 91%. Likewise, decreasing the fiber aspect ratio by 1.8 times decreases the done frictional pull-out work by 56.3% and boosts the fiber duct resistance against damage by improving the frictional shear bond strength.