Bond Strength Of Composite Resin Research Articles

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.

RESISTÊNCIA DA UNIÃO DE SISTEMAS ADESIVOS À DENTINA: INFLUÊNCIA DO HIPOCLORITO DE SÓDIO

The modification of the root canal system is of paramount importance to the success of endodontic treatment. This study aimed to evaluate the influence of sodium hypochlorite at concentrations of 2.5% and 4.5% in times of 30 and 60 minutes on the bond strength of composite resin to dentin. We used for this study teeth 20, which were divided into five groups of four elements, each element of the experimental group was immersed in a characteristic time and concentration of sodium hypochlorite of their group and the control immersed in saline. Later there were three composite restorations on each tooth, totaling a sample of 60 restorations. Each restaurant had its bonding to dentin submitted to microshear test, and the results were analyzed through statistical tests: the normal, anova and multiple variations. No significant influence on the adhesion of composite resins to dentin at a concentration of 2.5% at times of 30 and 60 minutes, and concentration of 4.5% in 30 minutes time. There was only influences the concentration 4.5% after a time of 60 minutes. It is concluded that sodium hypochlorite at 4.5% in contact with the dentine for a time of 60 minutes because influence on the bond strength of resin composite, which may cause recontamination of the channel system.

Estimation of the effect of acetone- or ethanol-based solvents on shear bond strength of composite resin using air- and blot-dry techniques.

An adequate amount of water is necessary to maintain the shape of collagen fibrils while excess water hampers dentin-resin bonding. Air-drying lacks control while blot-drying displaces water in a controlled manner. Solvents in adhesives affect the configuration of collagen fibrils. Thus, the present study aimed to compare the influence of air- or blot-drying methods on shear bond strength (SBS) of acetone- and ethanol-based adhesives. Thirty-six extracted noncarious third molars with similar crown heights were selected. Teeth were decoronated and randomly divided into two groups: after acid etching, Group I was treated with acetone-based adhesives and Group II with ethanol-based adhesives. They were again subdivided into subgroups A (blot-dried) and B (air-dried) containing nine samples each. Dentin surfaces were etched and rinsed. After the respective drying method, adhesive application and composite buildup were done. SBS was measured. The data were subjected to statistical analysis. Acetone-based adhesive showed the highest SBS in both drying methods. Further, blot-dried dentin produced significantly higher SBS than air-dried dentin. Solvent type and drying methods have an effect on the bond strength of total-etch adhesives to dentin. Acetone-based adhesives used with blot-drying techniques showed the best results.

Potential of Erythrosine-Mediated Photodynamic Therapy as a Cavity Disinfectant: Antibacterial Efficacy and Bonding Ability

This study aimed to evaluate the antibacterial efficacy of erythrosine-mediated photodynamic therapy (PDT) against &lt;i&gt;Streptococcus mutans&lt;/i&gt; (&lt;i&gt;S. mutans&lt;/i&gt;) in dentin and its effect on the shear bond strength (SBS) of composite resin to dentin. Eighty extracted human noncarious premolars were used in this study. Forty teeth were used for the antibacterial activity test, while the remaining 40 were used for the SBS test. Both experiments were conducted with 4 experimental groups (n = 10): control (distilled water), sodium hypochlorite (NaOCl, 6%), chlorhexidine (CHX, 0.12%), and erythrosine-mediated PDT. Antibacterial effects were evaluated by counting &lt;i&gt;S. mutans&lt;/i&gt; colony-forming units (CFUs). The SBS of composite resins to dentin was measured using a universal testing machine. All treatments (NaOCl, CHX, and PDT) demonstrated statistically significant differences in antibacterial activity compared with the control group (&lt;i&gt;p&lt;/i&gt; &lt; 0.05). The antibacterial effects were ranked from strongest to weakest as follows: NaOCl, PDT, and CHX. In the SBS test, the NaOCl group exhibited a statistically significant difference compared with the CHX, PDT, and control groups (&lt;i&gt;p&lt;/i&gt; &lt; 0.05), with the lowest bond strength. No statistically significant differences were found among the CHX, PDT, and control groups (&lt;i&gt;p&lt;/i&gt; &gt; 0.05). Erythrosine-mediated PDT exhibited significant antibacterial effects against &lt;i&gt;S. mutans&lt;/i&gt;, with higher antibacterial activity than CHX but lower than NaOCl. Only NaOCl negatively affected the bond strength of composite resin to dentin. In conclusion, erythrosine-mediated PDT shows potential as a cavity disinfectant due to its significant antibacterial effects against &lt;i&gt;S. mutans&lt;/i&gt; and lack of adverse effects on bond strength.

Shear bond strength of composite resin to dentin after Er, Cr: YSGG laser irradiation or phosphoric acid etching

Shear bond strength of composite resin to dentin after Er, Cr: YSGG laser irradiation or phosphoric acid etching

Bond Strength of Composite Resin to Bioceramic Cements: An In Vitro Study

Bioceramic endodontic cements, known for their antibacterial properties, calcium ion release, and alkaline pH, may come into contact with various irrigants after furcal perforation repair. This study aimed to evaluate the effect of different irrigating solutions and setting times on the shear bond strength (SBS) of Biodentine® (Septodont, Saint-Maur-des-Fosses Cedex, France) to a self-adhering flowable composite. Sixty Biodentine® (Septodont, Saint-Maur-des-Fosses Cedex, France) blocks were prepared and divided into two groups based on the setting time: 72 h and 7 days. These were further subdivided into five subgroups based on the irrigation solution applied: distilled water, sodium hypochlorite, ethylenediaminetetraacetic acid, chlorhexidine, and phosphoric acid. They were then restored with Dyad FlowTM (KerrTM, Orange, CA, USA). SBS and failure modes were assessed at 24 h and 6 months. A two-way analysis of variance (ANOVA) test was performed to analyze the effect of the different irrigating solutions and setting times on the SBS of Biodentine® (Septodont, Saint-Maur-des-Fosses Cedex, France) and Dyad FlowTM (KerrTM, Orange, CA, USA). The level of significance was set at a ≤0.05. At 24 h, SBS was significantly influenced by both the irrigant solution (p = 0.029) and setting time (p = 0.018); at 6 months, SBS was influenced only by the irrigating solutions (p &lt; 0.001). The predominant mode of bond failure was adhesive across all groups. In conclusion, while the setting time did not affect the bond strength, certain irrigating solutions reduced it. Thus, careful consideration of surface treatments applied to Biodentine® is crucial for successful endodontic and restorative outcomes.

Effect of photodynamic therapy with two photosensitizers on the microtensile bond strength of a universal adhesive to affected dentin

BackgroundThis study aimed to evaluate the impact of photodynamic therapy (PDT) using two photosensitizers, methylene blue and indocyanine green, on the microtensile bond strength of a universal adhesive to caries-affected dentin. MethodsThe occlusal enamel of 60 third molars was cut to expose the inner one-third of the dentin. Artificial caries were induced through a pH cycling process. The samples were divided into three groups: M (Methylene blue+ diode laser), I (Indocyanine green agents+ diode laser irradiation), and control. Each group was further divided into two subgroups according to the adhesive protocol (self-etch, total-etch). After restoring with Gradia composite resin, teeth were sectioned and exposed to 5000 thermal cycles. Microtensile bond strength was measured using a universal testing machine. The data were subjected to two- and one-way ANOVA and paired comparisons were performed by the Tamhane and Tukey tests. ResultsThe study found significant effects of the photosensitizer, etching pattern, and their interactions on the microtensile bond strength of composite resin to caries-affected dentin (P < 0.001). In the self-etching mode, PDT with indocyanine green exhibited significantly higher bond strength values compared to PDT with methylene blue (P = 0.001) and the control groups (P < 0.001). However, no significant differences were observed in the total-etch mode. (P = 0.54). ConclusionsThe etching mode played a more significant role in the bond strength when using the universal adhesive alongside PDT with methylene blue and indocyanine green. Employing two photosensitizers in PDT during the self-etch mode significantly increased the bond strength values.

Influence of different endodontic irrigants on shear bond strength of composite resin to coronal dentin: An in vitro study

Objectives: Endodontic irrigants are critical in root canal treatments, but their influence on the coronal dentin bond strength of composite restorations is a key concern for a favorable clinical prognosis. The present in vitro study explores the effect of different endodontic irrigants on shear bond strength of composite resin. Material and Methods: Fifty permanent human mandibular molars were sectioned to expose coronal dentin and divided into five groups. Each group received a specific irrigant treatment before composite resin bonding. Shear bond strength was examined using Instron Universal testing machine, and statistical analysis was conducted using post hoc Tukey’s test and analysis of variance. Results: Group A (Saline) showed a mean shear bond strength of 18.5 Megapascal (MPa). Group B [sodium hypochlorite (NaOCl)] had mean shear bond strength of 15.2 MPa. Group C [Chlorhexidine (CHX) Gluconate] exhibited mean shear bond strength of 20.3 MPa. Group D ethylenediaminetetraacetic acid (EDTA) recorded mean shear bond strength of 14.8 MPa, while Group E [citric acid (CA)] had the highest mean shear bond strength at 22.7 MPa. Conclusion: The type of endodontic irrigant used significantly affected the shear bond strength of composite restorations to coronal dentin. CHX gluconate and CA displayed superior bond strengths compared to Saline, NaOCl, and EDTA. This underscores the importance of irrigant selection in achieving successful composite restorations in endodontically treated teeth.

Effect of Chitosan Nanoparticle as an Antioxidant Material on Shear Bond Strength of Composite Resin to Enamel after External Bleaching

Effect of Chitosan Nanoparticle as an Antioxidant Material on Shear Bond Strength of Composite Resin to Enamel after External Bleaching

The efficacy of Er,Cr:YSGG laser and contemporary universal adhesive systems on composite resin repair bond strength: an in vitro study.

The aim of this study is to investigate the repair bond strength of composite resin following three different surface treatments (bur-grinding, silanization, and Er,Cr:YSGG laser irradiation) using various universal adhesives. A total of 160 resin composite specimens, produced in cylindrical form (6 × 2mm) with a nanohybrid composite resin within metal molds, were subjected to 5000 cycles of aging in a thermocycler. The aged samples were categorized into four groups based on surface treatments: control, bur, silane, and Er,Cr:YSGG laser. Following surface treatments, the specimens underwent repair using the same resin composite and four different adhesive systems: Tokuyama Universal Bond (TUB), Prime Bond Universal (PBU), Gluma Bond Universal (GBU), and Clearfil SE Bond (CSB). Subsequently, the specimens were subjected to shear forces, and statistical analysis was performed using two-way ANOVA and Tukey tests (p < 0.05). The failure modes were examined using a stereomicroscope, and the surface topography of the roughened resin composite was assessed through scanning electron microscopy (SEM). Results indicated that silane + GBU exhibited the highest shear bond strength (SBS) (15.61MPa) while control + TUB showed the lowest SBS (7.63MPa). Silane demonstrated significantly higher SBS values (p ≤ 0.05), with no significant difference observed between bur and laser methods (p = 0.998). It is recommended to include an additional silanization step before applying universal adhesive, as it effectively enhances the bond strength of the repaired composite.

Comparative Evaluation of Various Antioxidants on the Shear Bond Strength of Composite Resin to Bleached Enamel - An In Vitro Study.

To evaluate and compare the effect of various antioxidants on the shear bond strength of composite resin to bleached enamel. Labial enamel surfaces of 90 extracted human maxillary central incisors were randomly divided into five groups based on the antioxidant used as follows: Group I ( n = 20): Bleaching with 40% hydrogen peroxide gel for 10 min, without the use of an antioxidant; Group II ( n = 20): Bleaching followed by the use of 10% sodium ascorbate solution; Group III ( n = 20): Bleaching followed by the use of 5% grape seed extract solution; Group IV ( n =20): Bleaching followed by the use of 5% pine bark extract solution; and Group V ( n =20): Control group in which no bleaching was done. Groups I-IV were further subdivided into two subgroups of 10 teeth each, whether the antioxidant application and composite build-up was done immediately (subgroup A) or after 2 weeks of postbleaching (subgroup B). Shear bond strength of the specimens was tested under a universal testing machine. One-way analysis of variance followed by Mann-Tukey posthoc multiple comparison test was used to analyse the data. The level of significance was established at P < 0.05. Within the limitations of this study, it was observed that the use of antioxidants effectively reversed the compromised bond strength of bleached enamel. Among the antioxidants, 5% pine bark extract application after bleaching showed better bond strength.

Effect of herbal antioxidants on the shear bond strength of composite resin to bleached enamel at different time intervals.

Anterior tooth discolorations can be treated conservatively and noninvasively through bleaching to achieve the desired esthetic outcomes. However, bleaching along with composite resin is advisable for certain clinical cases for optimum results. However, shear bond strength (SBS) of composite resin to the bleached tooth gets significantly lowered. Before placing the composite restoration, the bleached enamel needs to be treated with antioxidant agents to increase its SBS. The study aims to evaluate and compare the effect of herbal antioxidants on SBS of composite resin to bleached enamel at different time intervals. Sixty extracted single-rooted maxillary incisors postdecoronation, keeping their labial surfaces up were mounted in cold-cure acrylic resin. The samples were randomly divided into: Group I - unbleached; Group II - 10% pine bark extract for 10 min postbleaching; Group III - 10% pine bark extract for 20 min postbleaching; Group IV - application of 10% rosemary extract for 10 min postbleaching, Group V - application of 10% rosemary extract for 20 min postbleaching; Group VI - no application of antioxidant. 35% hydrogen peroxide was used for bleaching all the samples except those which served as negative control. Later composite cylinder 4 mm in diameter and length were built on prepared enamel. The maximum load at failure was recorded using the universal testing machine. Data were analyzed using the analysis of variance and Tukey's t-test with significance level of P < 0.05. Highest load was exhibited by Group I. Group V showed satisfactory shear strength followed by Groups IV, III, II, and VI. Both 10% rosemary and 10% pine bark extracts showed better results when applied for 20 min as compared to 10 min application. Increased duration of antioxidant application increases the SBS.

Effects of different concentrations of bromelain and papain enzymes on shear bond strength of composite resin to deep dentin using an etch-and-rinse adhesive system.

The dentin substrate can be modified by proteolytic agents, which may affect the bonding strength of adhesive systems to the treated dentin surface. Papain, a cysteine protease enzyme with antibacterial and anti-inflammatory properties, can be used for deproteinization of dentin. An alternative deproteinizing enzyme is bromelain. This study aimed to evaluate the impact of deproteinization on the shear bond strength (SBS) of composite resin to deep dentin using different concentrations of bromelain and papain. Sixty upper premolars were extracted and randomly divided into 5 groups (n = 12 per group). In all groups, the dentin surface was etched with 37% phosphoric acid. Group 1 did not receive any enzyme treatment, group 2 was treated with a 10% papain solution, group 3 was treated with a 15% papain solution, group 4 was treated with a 6% bromelain solution, and group 5 was treated with a 10% bromelain solution. After applying an etch-and-rinse adhesive system, the specimens were restored with composite resin and the SBS was measured. Statistically significant differences were found between groups 2 and 3 (10% papain and 15% papain, p = 0.004), groups 2 and 4 (10% papain and 6% bromelain, p = 0.017), groups 4 and 5 (6% bromelain and 10% bromelain, p = 0.021), and groups 3 and 5 (15% papain and 10% bromelain, p = 0.005). Deproteinization with papain and bromelain at different concentrations after acid etching did not affect the SBS of composite resin to deep dentin when using an etch-and-rinse adhesive system. However, the group deproteinized with 15% papain demonstrated a higher SBS than the group deproteinized with 10% papain, and the group deproteinized with 6% bromelain showed a higher SBS compared to the group deproteinized with 10% bromelain.

Evaluation of Shear Bond Strength of Composite Resin Bonded to Dentin with Three Different Adhesive Systems

Aim of the study to measure the shear bond strength of composite resin bonded to dentin with three different adhesive system.The buccal surfaces of 30 non-carious, intact, extracted upper premolar (Freshly extracted for orthodontic treatment), were grinded with 600 grit silicon carbide paper to expose dentin surface. the samples were divided into three groups: G1, 10 teeth were bonded with an acetone-base total-etch Prime&amp;Bond NT G2, 10 teeth were bonded with an ethanol-base total-etch Excite. G3,10 teeth were bonded with an ethanol-and water-base total-etch Schotchbond 1. Shear bond strength is determined by using Instron testing machine.Results showed that excite adhesive system has statistically high significant increase in shear bond strength than Schotchbond 1.As conclusion; the lack of water in the adhesive may play a more important role than the type of solvent itself.

Effect of the Nd:YAG laser on the micro-tensile bond strength of composite resin to dentin with hypersensitivity using different universal adhesives.

This study aimed to evaluate the effect of the Nd: YAG laser on the tensile bond strength of composite resin to dentin with hypersensitivity using different universal bonding systems. After cutting the crown of 252 molars, buccal cervical enamel was removed at a thickness of approximately 2 mm, and 252 smooth dentin surfaces were exposed. Then they were etched with 0.5 M ethylenediaminetetraacetic acid (pH = 7.4) to stimulate hypersensitivity. The specimens were then randomly divided into 12 groups (n= 21) according to the surface treatments performed. After etching and bonding according to the manufacturer's recommendations in each group, the entire dentin surface was restored with Valux Plus composite resin. The samples were thermocycled and a universal test machine was used to measure the microtensile bond strength. The failure mode for each sample was observed under a stereomicroscope. For data analysis, the Bonferroni test, the independent t-test and the three-way anova test were used. The average microtensile bond strength in non-laser samples was higher than the average in laser samples (P<0.001). In comparison with the bonding agent type in both cases with and without laser, the highest average microtensile bond strength was related to ALL-BOND (P<0.001), meanwhile the lowest average tensile strength in samples without laser was related to G-Premio universal adhesive (P<0.001), and the lowest average microtensile strength in samples with laser belonged to Prime and Bond Elect group (P<0.001). Nd: YAG laser irradiation of the dentin surface before applying the adhesive significantly decreased the microtensile bond strength of the composite resin to the dentin surface. Key words:Nd:YAG laser, Bond strength, Dentin, hypersensitivity, Universal adhesives.

Influence of Diabetes Mellitus and Universal Adhesive Application Mode on the Bond Strength of Composite Resin to Dentine.

The aim of the current study was to evaluate the influence of diabetes mellitus and the mode of applying a universal adhesive on the shear bond strength of composite resin to dentin. Forty teeth were extracted from diabetic individuals who had been living with diabetes for a period of 5 to 15 years. These forty teeth were divided into two groups: twenty molars from patients with type 1 diabetes and twenty molars from patients with type 2 diabetes. The remaining twenty sound human molars were collected from non-diabetic patients. The collected teeth were assigned into 3 groups, and each group was further divided into 2 subgroups. Group A (n = 20): non-diabetic (ND) where sub group IA: Universal adhesive applied in the total-etch mode (n = 10) and sub group IIA: Universal adhesive applied in the self-etch mode (n = 10). Group B (n = 20): diabetic type 1 (D1) where sub group IB: Universal adhesive applied in the total-etch mode (n = 10) and sub group IIB: Universal adhesive applied in the self-etch mode (n = 10). Group C (n = 20): diabetic type 2 (D2). Where Sub group IC: Universal adhesive applied in the total-etch mode (n = 10) and sub group IIC: Universal adhesive applied in the self-etch mode (n = 10). A Teflon mold measuring 3mm in diameter was attached to the dentin surface, used to build Filtek Z550 to a height of 3mm. The specimens were fixed to the universal testing to measure shear bond strength. There was a statistically significant difference of Mean ±SD of shear bond strength among the three tested groups. In group A, the Mean ±SD were (21.710 ± 0.638), it was decreased in group B to (14.626 ± 0.726) and group C to (17.740 ± 0.668). Subgroup I had lower shear bond strength values than subgroup II in all tested groups. The difference between each subgroup in groups A, B, and C was significant. 1. Diabetes mellitus has an adverse effect on the shear bond strength of composite to dentine. 2. Type 1 diabetes mellitus significantly reduces the shear bond strength of composite resin to dentin. 3. Shear bond strength of the universal adhesive was higher when applied to dentin using the self-etch mode, as compared to the total etch mode, in all groups, regardless of whether the participants had diabetes or not. Key words:Diabetes Mellitus, Universal Adhesive, Application Mode, Shear bond Strength, Dentine, Composite.

Composite Resin Bond Strength to Zirconia and Base Metal Alloys Using Two Types of Intraoral Porcelain Repair Systems.

Objectives: This study aimed to evaluate the shear bond strength (SBS) of two repair composites (Crea.lign vs. PermaFlo) to a base metal alloy and zirconia ceramic. Materials and Methods: Sixty-four discs (12mm diameter, 1mm thickness) were fabricated using Wirobond base metal alloy and zirconia. They were then bonded with their respective composite resins (N=16) in each of the two porcelain chipping repair kit subgroups consisting of PermaFlo and Crea.lign. All specimens were stored in 37°C distilled water for 24 hours. Half of them were subjected to 10,000 thermal cycles (5-55°C, 30s). All specimens were tested for SBS with a universal testing machine. Failure types were analyzed using a digital camera. Analysis of the data was done by two-way ANOVA and Bonferroni post-hoc tests. Results: SBS was significantly affected by the type of composite resin. PermaFlo had a significantly higher SBS than Crea.lign to base metal alloy (P<0.001) and zirconia ceramic (P<0.001). Thermocycling decreased the SBS of both composites to base metal alloy (P<0.001) and zirconia (P<0.001). Conclusion: A universal adhesive could provide higher shear bond strength of zirconia and base metal alloy to composite resin than Crea.lign composite and the MKZ primer supplied by its manufacturer.

Shear bond strength characteristics on surface treatment modalities of CAD-CAM resin polymers.

The purpose of this in vitro study was to analyze the shear bond strength of composite resin to a commercially available high-performance polymer material for fixed, screw-retained full arch restorations. A total of 135 computer-aided design and computer-aided manufacturing, high-performance polymer (HPP) blocks were cut and obtained from discs (Trilor 95, Harvest Dental, Brea, CA). The samples were 10mm × 10mm × 10mm. The specimen surfaces were grouped as untreated (Group A), 50 μm Al2O3 (Group B), 110 μm Al2O3 (Group C), Rocatec (3M, St. Paul, MN) activated with silica-modified alumina oxide treatment (Group D); and trimmed coarsely with a carbide bur (Group E). Group A samples were used as controls. After surface treatments, the specimens were gently cleansed with oil-free steam and alcohol wipes. Surface conditioning was performed on all physically treated samples. The manufacturer's recommendations were followed for bonding composite resin to the samples with light-cured Visio.link (Bredent, Chesterfield, UK). Cylinders were veneered with composite resins (diameter 5mm, height 4mm) and polymerized on the specimen surfaces through plastic tubes. Twenty-seven specimens were used for each testing group and aging tests were performed. The experimental samples were thermocycled. Shear bond strength and scanning electron microscopic tests were performed. Means and standard deviations were calculated. Statistical analysis was performed with post-hoc Tukey tests. Statistical analysis revealed that there was a significant difference between the groups (p<0.001). The highest shear bond strengths were achieved for the specimens bonded with Visio.link without physical surface treatments (270.47MPa). The lowest bond strengths were found for specimen surfaces abraded with 110 μm Al2O3 (117.03 Mpa) CONCLUSIONS: The results of this laboratory study indicated that the specimens used with Visio.link as provided by the manufacturer had the highest shear bond strengths between the composite resin and high-performance polymer test specimens. Modifications of the high-performance polymer surfaces with carbide burs did not change bonding strengths with the composite materials.

The Effect of 10% Sodium Ascorbate and Er: YAG Laser on the Microtensile Bond Strength of Composite Resin to Bleached Enamel

Background: There are various methods proposed to prevent the reduction of substrate micro tensile bond strength to bleached enamel. Therefore, this study aims to evaluate and compare the effectiveness of two common methods, namely 10% sodium ascorbate and Er:YAG laser irradiation, in increasing the microtensile bond strength of composite resins to bleached enamel. Methods: In this in vitro study, 72 maxillary premolar teeth were divided into four equal groups: bleached control group, unbleached control group, treated with 10% sodium ascorbate, and Er:YAG laser-treated group (60 mJ, frequency = 10 Hz, and power of 0.6 W with a 400-µm diameter tip). The samples were cut by a CNC cutting machine for a microtensile bond strength test. Results: The Er:YAG laser group showed the highest mean bond strength (27.3 MPa), while the bleached control group had the lowest (15.06 Mpa). There was a significant difference between the bleached and unbleached control groups (P&lt;0.001). Samples prepared with 10% sodium ascorbate and the Er:YAG group had higher tensile bond strength than the bleached control group (P&lt;0.0001). Tensile bond strengths were not significantly different between the 10% sodium ascorbate and the Er:YAG laser preparation groups (P=0.361). Conclusion: The findings of this study indicate that the microtensile bond strength of composite resins to bleached enamel can be increased by 10% sodium ascorbate and Er:YAG laser irradiation.

Evaluation of antioxidant application on bond strength of composite resins to bleached enamel

Abstract Aim: This study aims to assess and evaluate the application of 10% sodium ascorbate, 5% green tea extract, 5% pomegranate peel extract, and 5% grape seed extract on shear bond strength of composite to bleached enamel. Materials and Methods: Sixty extracted human maxillary central incisors were randomly divided into seven groups. The enamel surface of these specimens was bleached with hydrogen peroxide (35%), except group VII (control group). Postbleaching, the specimens of group II were placed in artificial saliva for 2 weeks before restoration and the specimens of groups III and IV and groups V and VI underwent antioxidant application; 10% sodium ascorbate, 5% green tea extract, 5% pomegranate peel extract, 5% grape seed extract, respectively, for 10 min, followed by composite resin restoration, respectively. The specimens of group I were restored with composite resin immediately after bleaching. The specimens’ shear bond strength was tested using universal testing equipment. The data obtained were statistically analyzed using a one-way analysis of variance and the Tukey post hoc test. Results: There was no statistically significant difference in the effects of various antioxidants on the shear bond strength of bleached enamel. Conclusion: Within the constraints of the study, it was concluded that the application of antioxidants efficiently recovered the bond strength of bleached enamel. The application of 5% grape seed extract treatment demonstrated better bond strength among the antioxidants tested. Clinical Significance: Antioxidants can be used immediately following bleaching to restore resin composite bond strength without the requirement of delay in the treatment to reduce the nascent oxygen species in bleached teeth.