• The Journal of Advanced Prosthodontics
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• v.6 no.5
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• pp.333-345
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• 2014

PURPOSE. Bonding agents (BA) are the crucial weak link of composite restorations. Since the commercial materials' compositions are not disclosed, studies to formulize the optimum ratios of different components are of value. The aim of this study was to find a proper formula of BAs. MATERIALS AND METHODS. This explorative experimental in vitro study was composed of 4 different sets of extensive experiments. A commercial BA and 7 experimental formulas were compared in terms of degree of conversion (5 experimental formulas), shear bond strength, mode of failure, and microleakage (3 experimental formulas). Statistical analyses were performed (${\alpha}$=.05). The DC of selected formula was tested one year later. RESULTS. The two-way ANOVA indicated a significant difference between the shear bond strength (SBS) of two tissues (dentin vs. enamel, P=.0001) in a way that dentinal bonds were weaker. However, there was no difference between the four materials (P=.283). The adhesive mode of failure was predominant in all groups. No differences between the microleakage of the four materials at occlusal (P=.788) or gingival (P=.508) sites were detected (Kruskal-Wallis). The Mann-Whitney U test showed a significant difference between the microleakage of all materials (3 experimental formulas and a commercial material) together at the occlusal site versus the gingival site (P=.041). CONCLUSION. A formula with 62% bisphenol A-glycidyl methacrylate (Bis-GMA), 37% hydroxy ethyl methacrylate (HEMA), 0.3% camphorquinone (CQ), and 0.7% dimethyl-para-toluidine (DMPT) seems a proper formula for mass production. The microleakage and SBS might be respectively higher and lower on dentin compared to enamel.

• The Journal of Advanced Prosthodontics
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• v.10 no.5
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• pp.340-346
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• 2018

PURPOSE. In this study, the shear bond strengths (SBS) of luting cements to fixed superstructure metal surfaces under various seating forces were investigated. MATERIALS AND METHODS. Seven different cements [Polycarboxylate (PCC), Glass-Ionomer (GIC), Zinc phospahate (ZPC), Self-adhesive resin (RXU), Resin (C&B), and Temporary cements ((RXT) and (TCS))] were bonded to a total number of 224 square blocks ($5{\times}5{\times}3mm$) made of one pure metal [Titanium (CP Ti) and two metal alloys [Gold-Platinum (Au-Pt) and Cobalt-Chrome (Co-Cr)] under 10 N and 50 N seating forces. SBS values were determined and data were analyzed with 3-way ANOVA. Pairwise comparisons and interactions among groups were analyzed with Tukey's simultaneous confidence intervals. RESULTS. Overall mean scores indicated that Co-Cr showed the highest SBS values ($1.96{\pm}0.4$) (P<.00), while Au-Pt showed the lowest among all metals tested ($1.57{\pm}0.4$) (P<.00). Except for PCC/CP Ti, RXU/CP Ti, and GIC/Au-Pt factor level combinations (P<.00), the cements tested under 10 N seating force showed no significantly higher SBS values when compared to the values of those tested under 50 N seating force (P>.05). The PCC cement showed the highest mean SBS score ($3.59{\pm}0.07$) among all cements tested (P<.00), while the resin-based temporary luting cement RXT showed the lowest ($0.39{\pm}0.07$) (P<.00). CONCLUSION. Polycarboxylate cement provides reliable bonding performance to metal surfaces. Resin-based temporary luting cements can be used when retrievability is needed. GIC is not suitable for permanent cementation of fixed dental prostheses consisting of CP Ti or Au-Pt substructures.

• The Journal of Advanced Prosthodontics
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• v.10 no.4
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• pp.308-314
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• 2018

PURPOSE. Plasma activation of hydrophobic zirconia surfaces might be suitable to improve the bond strength of luting materials. The aim of this study was to analyze the influence of nonthermal argon-plasma on the shear bond strength (SBS) between zirconia and different combinations of 10-MDP adhesive systems and luting composites after artificial aging. MATERIALS AND METHODS. Two hundred forty Y-TZP specimens were ground automatically with $165{\mu}m$ grit and water cooling. Half of the specimens received surface activation with nonthermal argon-plasma. The specimens were evenly distributed into three groups according to the adhesive systems ([Futurabond U, Futurabond M, Futurabond M + DCA], VOCO GmbH, Germany, Cuxhaven) and into further two subgroups according to the luting materials ([Bifix SE, Bifix QM], VOCO GmbH). Each specimen underwent artificial aging by thermocycling and water storage. SBS was measured in a universal testing machine. Statistical analysis was performed using ANOVA and $Scheff{\grave{e}}$ procedure with the level of significance set to 0.05. RESULTS. Surface activation with nonthermal plasma did not improve the bond strength between zirconia and the tested combinations of adhesive systems and luting materials. The plasma-activation trended to reveal higher bond strength if the self-etch luting material (Bifix SE) was used, irrespective of the adhesive system. CONCLUSION. Plasma-activation seems to be suitable to improve bond strength between zirconia and self-etch resin materials. However, further research is necessary to identify the influence of varying plasma-parameters.

• The korean journal of orthodontics
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• v.43 no.2
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• pp.96-100
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• 2013

Objective: To evaluate the effects of contamination by either blood or a hemostatic agent on the shear bond strength (SBS) of orthodontic buttons. Methods: We used 45 freshly extracted, non-carious, impacted third molars that were divided into 3 groups of 15. Each tooth was etched with 37% phosphoric acid gel for 30 s. Human blood or the blood stopper agent was applied to the tooth surface in groups I and II, respectively. Group III teeth were untreated (controls). Orthodontic buttons were bonded to the teeth using light-curing composite resin. After bonding, the SBS of the button was determined using a Universal testing machine. Any adhesive remaining after debonding was assessed and scored according to the modified adhesive remnant index (ARI). ANOVA with post-hoc Tukey's test was used to determine significant differences in SBS and Fisher's exact test, to determine significant differences in ARI scores among groups. Results: ANOVA indicated a significant difference between groups (p < 0.001). The highest SBS values were measured in group III ($10.73{\pm}0.96$ MPa). The SBS values for teeth in groups I and II were significantly lower than that of group III (p < 0.001). The lowest SBS values were observed in group I teeth ($4.17{\pm}1.11$ MPa) (p < 0.001). Conclusions: Contamination of tooth surfaces with either blood or hemostatic agent significantly decreased the SBS of orthodontic buttons. When the contamination risk is high, it is recommended to use the blood stopper agent when bonding orthodontic buttons on impacted teeth.

• The Journal of Advanced Prosthodontics
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• v.13 no.5
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• pp.292-303
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• 2021

PURPOSE. The aim of this in vitro study was to evaluate the effect of silane and universal adhesive applications on the micro-shear bond strength (µSBS) of different resin-matrix ceramics (RMCs). MATERIALS AND METHODS. A total of 120 slides (14 × 12 × 1 mm) were produced from 5 different RMC materials (GC Cerasmart [GC]; Brilliant Crios [BC]; Grandio blocs [GB]; Katana Avencia [KA]; and KZR-CAD HR 2 [KZR]) and sandblasted using 50 ㎛ Al₂O₃ particles. Each RMC material was divided into six groups according to the surface conditioning (SC) method as follows: control (G1), silane primer (G2), silane-free universal adhesive (G3), silane-containing universal adhesive (G4), silane primer and silane-free universal adhesive (G5), and silane primer and silane-containing universal adhesive (G6). Three cylindric specimens made from resin cement (Bifix QM) were polymerized over the treated surface of each slide (n = 12). After thermal cycling (10000 cycles, 5 - 55℃), µSBS test was performed and failure types were evaluated using a stereomicroscope. Data were analyzed using 2-way ANOVA and Tukey tests (α = .05). RESULTS. µSBS values of specimens were significantly affected by the RMC type and SC protocols (P < .001) except the interaction (P = .119). Except for G2, all SC protocols showed a significant increase in µSBS values (P < .05). For all RMCs, the highest µSBS values were obtained in G4 and G6 groups. CONCLUSION. Only silane application did not affect the µSBS values regardless of the RMC type. Moreover, the application of a separate silane in addition to the universal adhesives did not improve the µSBS values. Silane-containing universal adhesive was found to be the best conditioning method for RMCs.

• Restorative Dentistry and Endodontics
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• v.45 no.1
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• pp.10.1-10.8
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• 2020

Objectives: This study aimed to compare the shear bond strength (SBS) of a self-adhering flowable composite (Dyad Flow) and a bulk-fill flowable composite (Smart Dentin Replacement [SDR]) to several pulp-capping materials, including MTA Plus, Dycal, Biodentine, and TheraCal. Materials and Methods: Eighty acrylic blocks with 2-mm-deep central holes that were 4 mm in diameter were prepared and divided into 2 groups (n = 40 each) according to the composite used (Dyad Flow or SDR). They were further divided into 4 sub-groups (n = 10 each) according to the pulp-capping agent used. SBS was tested using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed using 2-way analysis of variance. A p value of < 0.05 was considered to indicate statistical significance. Results: A statistically significant difference (p = 0.040) was found between Dyad Flow and SDR in terms of bond strength to MTA Plus, Dycal, Biodentine, and TheraCal. Conclusions: Among the 8 sub-groups, the combination of TheraCal and SDR exhibited the highest SBS.

• The Journal of Advanced Prosthodontics
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• v.16 no.3
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• pp.163-173
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• 2024

PURPOSE. This study assessed the effect of storage time on chemical structure of a single-bottle and a two-bottle experimental ceramic primer and micro-shear bond strength (µSBS) of composite to ceramic. MATERIALS AND METHODS. This study was conducted on 60 sintered zirconia and 60 feldspathic porcelain blocks. Half of the specimens (n = 30) were subjected to surface treatment with the single-bottle Clearfil ceramic primer (n = 15) and two-bottle experimental primer (n = 15) after 24 hours. The remaining half received the same surface treatments after 6 months storage in distilled water. Composite cylinders were bonded to the ceramics, and they were then subjected to µSBS test. Also, the primers underwent Fourier-transform infrared spectroscopy (FTIR) after 24 hours and 6 months to assess their chemical structure. Data were analyzed with 3-way ANOVA and adjusted Bonferroni test (alpha = 0.05). RESULTS. The µSBS of both ceramics significantly decreased at 6 months in one-bottle ceramic primer group (P = .001), but it was not significantly different from the two-bottle experimental primer group (P = .635). FTIR showed hydrolysis of single-bottle primer, cleavage of silane and 10-MDP bonds, and formation of siloxane bonds after 6 months. CONCLUSION. Six months of storage caused significant degradation of single-bottle ceramic primer, and consequently had an adverse effect on µSBS.

• The Journal of Advanced Prosthodontics
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• v.12 no.5
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• pp.273-282
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• 2020

PURPOSE. To assess shear bond strengths (SBS) of resin composites on aged and non-aged prosthetic materials with various surface treatments. MATERIALS AND METHODS. Cerasmart (CE), Vita Enamic (VE), Vita Mark II (VM), and IPS e.max CAD (EC) blocks were sliced, and rectangular-shaped specimens (14 × 12 × 1.5 mm; N = 352) were obtained. Half of the specimens were aged (5000 thermal cycles) for each material. Non-aged and aged specimens were divided into 4 groups according to the surface treatments (control, air abrasion, etching, and laser irradiation; n = 11) and processed for scanning electron microscopy (SEM). The repair procedure was performed after the surface treatments. SBS values and failure types were determined. Obtained data were statistically analyzed (P≤.05). RESULTS. The material type, surface treatment type, and their interactions were found significant with regard to SBS (P<.001). Aging also had a significant effect on prosthetic material-resin composite bonding (P<.001). SBS values of non-aged specimens ranged from 12.16 to 17.91 MPa, while SBS values of aged specimens ranged from 9.46 to 15.61 MPa. Non-aged VM in combination with acid etching presented the highest score while the control group of aged CE showed the lowest. CONCLUSION. Etching was more effective in achieving durable SBS for VM and EC. Laser irradiation could be considered as an alternative surface treatment method to air abrasion for all tested materials. Aging had significant effect on SBS values generated between tested materials and resin composite.

• Restorative Dentistry and Endodontics
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• v.42 no.3
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• pp.188-199
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• 2017

Objectives: This in vitro study evaluated the effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin. Materials and Methods: Flat coronal dentin surfaces were prepared in 120 extracted human molars. Teeth were randomly divided into 5 groups (n = 24) according to 5 different surface pre-treatments: No pre-treatment (control); 1M carbodiimide (EDC); 0.1% epigallocatechin-3-gallate (EGCG); 2% minocycline (MI); 10% sodium ascorbate (SA). After surface pre-treatment, adhesive (Adper Single Bond 2 [SB], 3M ESPE) was applied. Composite was applied into transparent plastic tubes (2.5 mm in diameter), which was placed over the bonded dentin surface. From each group, 10 samples were subjected to shear bond strength (SBS) evaluation at 24 hours (immediate) and remaining 10 samples were tested after 6 months (delayed). Additionally, 4 samples per group were subjected to scanning electron microscopic analysis for observation of resin-dentin interface. The data were statistically analysed with Shaperio-Wilk W test, 2-way analysis of variance (ANOVA), and post hoc Tukey's test. Results: At 24 hours, SBS of all surface pre-treatment groups were comparable with the control group, with significant differences found between EDC and SA groups only (p = 0.009). After 6 months storage, EDC, EGCG, and MI pre-treatments preserved the resindentin bond strength with no significant fall. Conclusions: Dentin pre-treatment with all the dentin biomodifiers except SA resulted in significant preservation of resin-dentin bond over 6 months storage period, without negatively affecting the immediate bond strength of the etch and rinse adhesive tested.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.2
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• pp.200-209
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• 2017

The aim of this study was to evaluate the shear bond strength (SBS) of three typical restorative materials - glass ionomer cement (GIC), resin-modified glass ionomer (RMGIC) and composite resin (CR) - to different pulp capping materials, i.e., Theracal $LC^{TM}$ (TLC), $Biodentine^{TM}$ (BD), and $ProRoot^{TM}$ white MTA (WMTA). 90 acrylic blocks with a center hole were prepared. The holes were completely filled with three pulp capping materials (TLC, BD, and WMTA), with 30 specimens per capping material. The samples were then randomly divided into 3 subgroups of 10 specimens each and were overlaid with GIC, RMGIC, or CR. A total 9 specimen groups were prepared. The SBS was assessed using a universal testing machine. Kruskal-Wallis test and Mann-Whitney's test were performed to compare the SBS among the subgroups (p < 0.05). After the SBS test, the fractured surfaces were examined under a stereomicroscope at a magnification of $25{\times}$. The highest and lowest SBS values were recorded for TLC-CR and TLC-GIC, respectively. With regard to the SBS to the three pulp capping materials, CR was found to be superior to RMGIC and GIC. BD showed a higher SBS compared to TLC and WMTA when used with GIC.