Bond Strength Of Composite Resin Research Articles

Evaluation of bond strength of polyether ether ketone (PEEK) to composite resin on hypobaric and hyperbaric conditions

The aim of this study was to investigate the shear bond strength of composite resin to PEEK under hypobaric and hyperbaric pressure changes in different PEEK surface treatments. Ninety-six PEEK specimens were divided into three groups (n = 32). PEEK surfaces were sandblasted; acid-etched, and non-treated. Every group was then divided into three sub-groups (n = 10) for simulating hyperbaric pressure (2.8 atm-18 m under sea level), hypobaric pressure (0.34 atm-8,200 m high altitude), and the control group (atmospheric pressure). The specimens underwent pressure cycles for 20 days. Results were compared by using ANOVA followed by the post-hoc Tukey test. Variations in bond strength within each group were also evaluated by the Weibull modulus. Regardless of the environmental pressure changes, it was determined that the bonding strength and the Weibull modulus were the highest in the acid-etched PEEK. Bonding strengths were lower in all groups after exposure to environmental pressure changes, but this difference was not statistically different. Bond strengths between the PEEK material and composite resin can be affected by environmental pressure, while surface modification of the PEEK material plays an important role in bond strength. Dentists should take importance in choosing the appropriate material on patients who are exposed to different barometric changes, as fractures on restorations may be life-threatening.

The effect of diabetes mellitus on the shear bond strength of composite resin to dentin and enamel.

Diabetes mellitus might be linked to the deterioration of certain physical properties of dentin and enamel. This study aimed to determine the effect of two types of diabetes on the shear bond strength of enamel and dentin, byusing the single bond universal bonding system. Sixty specimens [from 15 teeth; 5 from each group-non-diabetic (ND), Diabetic type I (D1), and Diabetic type II (D2)], were prepared with equal amounts of dentin (n = 5) and enamel (n = 5). Enamel specimens (E20) were etched with 37% phosphoric acid, for 20s, and dentin specimens (D15) were etched for 15s. A standard shear bond strength test was performed on all specimens. Their failure modes were also studied under a scanning electron microscope, and the data were analyzedby using ANOVA and Post Hoc Tukey's test (a = 0.050). For the enamel groups, significant differences were only noticed between the ND and D1 (P < 0.050) groups, and between the ND and D2 (P < 0.050) groups. In the dentin groups, there was a significant difference only between the ND and D1 (P < 0.050) groups. The micrographs showed that the ND group had the highest number of specimens with cohesive failure and D1 had the highest number of specimens with adhesive failure. It can be concluded that both types of diabetes reduce the shear bond strength of composite resin on dentin and enamel. However, it seems that the negative effect of diabetes on shear bond strength of dental composite resin is more drastic in individuals with type I diabetes as compared with type II.

Efektivitas Teknik Air Abrasion pada Preparasi Gigi terhadap Kekuatan Ikatan Resin Komposit (Laporan Penelitian)

ABSTRACTBackground:Minimal intervention dentistry promote the philosophy of prevention, remineralization, and minimal invasive in the practice of dentistry. One of the technique employed by this concept is air abrasion. Aim: to discover the effectiveness of air abrasion technique on the dental caries prepation towards the bond strength of composite resin with the method of scoping review. Method: This research utilize the PRISMA diagram, based on PubMed, PMC and Elsevier database with the keywords of: ((("air abrasion" OR "air abraded") AND (composite OR "composite resin")) AND "bond strength"). Result: Based on the criteria, 14 articles were found and divided into 5 categories Conclusion: the mean and SD of air abrasion technique with self-etch bonding type against microtensile bond strength test is 20.1 ± 5.3 - 71.7 ± 8.3 MPa; with the total-etch bonding type is 25.2 ± 7.2 - 55.08 ± 3.74 MPa, with total-etch bonding type against tensile bond strength test is 15.83 ± 1.51 - 20.80 ± 3.95 MPa; with self-etch bonding type against shear bond strength test is 6.7 - 25.32 ± 4.91 MPa; and with total etch is 13.88 ± 5.50 - 30.25 ± 7.00 MPa.

Evaluation of the Effects of Bromelain and Papain Enzymes on Shear Bond Strength of Composite Resin to Enamel.

Aim This study aimed to evaluate the effects of 6% bromelain and 10% papain enzymes on shear bond strength (SBS) of composite resin to enamel compared to conventional 37% phosphoric acid etching. Materials and Methods 50 human maxillary premolar teeth were randomly divided into 5 groups (G1–G5/n = 10). In G1 and G2, after etching enamel with 37% phosphoric acid for 15 seconds and washing the surface, 10% papain and 6% bromelain enzymes were used, respectively. In G3 and G4, 6% bromelain or 10% papain enzymes were applied on enamel. In G5, the enamel surface was etched with 37% phosphoric acid for 15 seconds. A two-step etch-and-rinse adhesive system (Adper Single Bond 2) was applied. A nanohybrid composite (Z350) was placed using Teflon molds. All the samples were then subjected to the SBS test using a universal testing machine. Data analysis was performed using a one-way ANOVA test followed by the Tukey test. p values less than 0.05 were considered significant. Results Comparison of the mean SBS between G1, G2, and G5 shows no significant differences (p > 0.05); however, they had higher mean SBS compared with G3 and G4 (p < 0.0001). Conclusions The shear bond strength of composite to enamel was not affected significantly using either 6% bromelain or 10% papain enzymes after 37% phosphoric acid application. Moreover, 6% bromelain and 10% papain enzymes were not as effective as 37% phosphoric acid alone.

“Effect of three vitamin antioxidants on reversal of shear bond strength of bleached enamel: An in-vitro Study.”

ABSTRACT&#x0D; Aims and objectives: To evaluate the effect of Sodium ascorbate, Alpha-tocoferol and Beta-carotene vitamins antioxidant on reversing the bond strength between resin composite and bleached enamel surface.&#x0D; Materials and methods: The study focussed on use of three vitamin antioxidants. All the groups in the study were subjected to bleaching containing 35% Hydrogen peroxide. Resin restoration were done after 1 week and immediately after bleaching without any antioxidant in Group 1 and 2 respectively. While in Group 3, 4 and 5, following bleaching treatment, samples were exposed to Beta-carotene gel, Sodium Ascorbate solution and Alpha-tocoferol gel respectively for 10 minutes, before resin restoration was done. Specimens were then subjected to Universal Testing Machine. The results were statistically analysed using ANOVA test and Tukey Honest Significant Difference (HSD) test, to comparatively analyse statistical differences between the groups.&#x0D; Results: The mean shear bond strength values of Group 4 (Sodium Ascorbate solution) showed significantly high bond strengths than Groups 3 (Beta-carotene gel) and 5 (Alpha-tocoferol gel).&#x0D; Conclusion: Treatment of bleached enamel with Sodium ascorbate and Alpha tocoferol antioxidants has significantly improved the shear bond strength of composite resin to enamel.&#x0D; Keywords: alpha-Tocopherol, Antioxidants, Ascorbic Acid, beta Carotene

The Role of Epigallocathecin-3-gallate as an Antioxidant After Dental Bleaching on Shear Bond Strength of Composite Resin Restoration

Background: Tooth discoloration can be treated with dental bleaching using Hydrogen peroxide (H2O2). Dental bleaching may interfere with the shear bond strength of composite resins because the remaining free radicals can affect bonding polymerization. Epigallocatcehin-3-gallate (EGCG) as an antioxidant can neutralize the free radicals produced during bleaching process. Purpose: Analyze the role of EGCG antioxidants in increasing the shear bond strength of composite resin after bleaching.. Reviews: Of the seven journals included in this literature review, six journals reported significant difference, and one journal noted no significant difference in the shear bond strength of composite resin following the EGCG application. Conclusion: The use of EGCG can increase the shear bond strength value of post-bleaching composite resin restorations.

Pomegranate (Punica granatum L.) gel extract as an antioxidant on the shear bond strength of a resin composite post-bleaching application with 40% hydrogen peroxide

Background: Tooth discoloration can be treated with tooth bleaching. Bleaching using 40% hydrogen peroxide can reduce the shear bond strength of resin composite because there are free radicals on the tooth surface, so it can delay the restoration. The application of antioxidants can eliminate free radicals after the bleaching procedure and increase the shear bond strength of the composite resin. The common antioxidants are ascorbic acid and natural ingredients, such as pomegranate (Punica granatum L.). Purpose: To determine the effect of pomegranate extract gel on the shear bond strength of composite resin after 40% hydrogen peroxide bleaching application. Methods: This research used 32 maxillary first premolars that were divided into four groups. The samples were bleached, then the labial was prepared and antioxidant gel was applied: group P1 pomegranate gel extract of 5%, group P2 pomegranate gel extract of 10%, group K1 positive control ascorbic acid gel of 10% and group K2 as the negative control. The samples were restored with a nanohybrid composite resin. The shear bond strength was tested using a universal testing machine. The data were tested using a one-way ANOVA followed by a post-hoc LSD test. Results: The pomegranate gel extract increased the shear bond strength of the composite resin after the bleaching procedure of 40% hydrogen peroxide compared with the ascorbic acid gel group and the negative control group. The one-way ANOVA test showed a significant difference (p&lt;0.05). The post-hoc LSD test showed significant differences between the treatment and negative control groups (p&lt;0.05). Conclusion: The pomegranate gel extract as an antioxidant increased the shear bond strength of the composite resin restoration after the 40% hydrogen peroxide bleaching application.

The Effects of Different Antioxidant Agents on the Microtensile Bond Strength of Composite Resin to Bleached Enamel

Objective: The objective of this in vitro study is to examine the effect of antioxidants on the bonding strength of composite resin to bleached enamel. Materials and Methods: One hundred twenty non decay teeth were used in this study. Specimens were cut from the enamel cement junction. Then the specimens were randomly assigned into two groups-office bleaching and home bleaching. Bleaching antioxidants were applied to the first 12 subgroups. The specimens in the remaining 12 groups were kept in artificial saliva for 14 days and antioxidants were applied. Composite resin restoration was applied to all specimens. A cutting device was employed to obtain six specimens (0.9mm) from each tooth, and the microtensile bond strength (μTBS) test was performed. Data were analyzed using one-way ANOVA, the paired t-test, and Duncan’s post hoc test (p=0.05). Results: In office bleaching specimens, immediate antioxidant application increased the μTBS values (p&lt;0.05). Comparisons of the antioxidants individually revealed that bonding values increased after two weeks in specimens subjected to antioxidant application (p&lt;0.05). In office bleaching specimens, immediate antioxidant application increased the μTBS values (p&gt;0.05). Mean μTBS values in the groups to which antioxidants were applied two weeks after home bleaching were higher than those in the groups in which antioxidants were applied immediately. Conclusion: The use of antioxidants after bleaching may increase the MTBS value. The clinician should take this into account especially in immediate restoration applications after bleaching.

In vitro effect of Er,Cr:YSGG laser on microtensile bond strength of composite resin to dentin using two different bonding systems

In vitro effect of Er,Cr:YSGG laser on microtensile bond strength of composite resin to dentin using two different bonding systems

Effect of different tooth whitening systems in combination with buffering and antioxidant agents on the shear bond strength of composite resin – An invitro study

Aim: The purpose of this in-vitro study was to evaluate the effect of tooth whitening systems on bond strength of composite resin. Material and Methods:One hundred and twenty maxillary central incisors (n=120) were divided into two groups based on the tooth whitening procedure used. Group 1: Bleaching (Pola Office, USA), Group 2: Micro abrasion (Opalustre, Australia). The samples subdivided into three groups depending on the surface treatments. Group A: Control (no surface treatment), Group B: Buffering agent (Sodium bicarbonate), Group C: buffering agent followed by Antioxidant (Sodium ascorbate). After the surface treatments, the groups were further subdivided into two (I &amp; II), based on the storage period in artificial saliva before the composite restoration.Composite resin was bonded to the labial surface of the teeth perpendicular to the long axis and the specimens were stored in artificial saliva for 24 hours. The samples were then subjected to shear bond strength test under the Universal testing machine. Statistical analysis: The results obtained were subjected to statistical analysis using a two-way ANOVA test, independent t-test, and Tukeys multiple post hoc tests. The p value was set &lt;0.05. Results:The results obtained have shown that out of all the groups, Group 1 with CII showed higher bond strength and Group 1 with AI shower lower values of bond strength. Among the groups, all the groups surface treated with buffering agent and antioxidant showed higher values of bond strength than control and buffering agent groups. The delay in time period showed significant difference in Group 1 than in Group 2. Conclusions: Within the limitations of the current study, bleaching and micro abrasion followed by surface treatment using buffering agent followed by antioxidant application showed improved bond strength than the other groups after bleaching. Key Words: Bleaching, Microabrasion, Buffering agent, Antioxidant, Bond strength.

Effect of Root Canal Filling Materials and Pretreatment with Solvents on the Shear Bond Strength of Composite Resin with Primary Tooth Dentin.

Aim Root canal filling materials have the tendency to inhibit adhesion of resin-based composites. This study was aimed at evaluating the effect of root canal filling materials and their solvents on the shear bond strength (SBS) of resin composite with the primary tooth dentin. Methods and Materials Seventy-two intact anterior primary teeth were selected. Smooth dentinal surfaces were prepared to a minimum diameter of 3 mm and thickness of 1.5–2.0 mm. The samples were equally divided into six groups (n = 12). In group 1: control group, no root filling material; in group 2: Metapex, no solvent; in group 3: Metapex+ethanol solvent; in group 4: ZOE, no solvent; in group 5: ZOE+ethanol solvent; and in group 6: ZOE+orange oil solvent were applied. Then, dentin surfaces were etched, and composite restorations were placed and cured. The specimens were stored in distilled water at 37°C for 24 hours. SBS values were determined using a universal testing machine. Results The SBS values of composite to dentin in groups 2 and 4 were significantly lower than those in the control group (P < 0.001). Cleansing of the specimens with 96% ethanol after removal of Metapex significantly increased the composite-dentin bond (P < 0.001). Applying ZOE, only orange oil solvent significantly increased the SBS of the composite to the primary tooth dentin (P = 0.01). Conclusion To reduce the negative effects of endodontic root filling materials on the SBS of composite and primary tooth dentin, ethanol is a suitable solvent when Metapex is used, while orange oil might be a better choice than ethanol when applying ZOE.

The Bond Strength of Universal Adhesives with Different Acidities to Calcium Silicate-Based Materials

Objective: To compare the micro-shear bond strengths of 3 different universal adhesives to 2 different calcium silicate-based materials. Methods: A hole was prepared in the center of the top surfaces of 60 cylindrical acrylic blocks, and the blocks were randomly divided into 2 groups (n=30) according to biomaterial filling; NeoMTA Plus (Avalon Biomed Inc. Bradenton, FL, USA) and ProRoot MTA (Dentsply Tulsa, Tulsa, OK, USA). Biomaterials were prepared according to the manufacturers’ instructions. The sample surfaces were flattened after the initial setting, and the samples were incubated for 24h at 37°C. After placing the biomaterials in the prepared holes, the specimens were randomly divided into 3 subgroups (n=10) according to adhesive; G-Premio Bond (GC Corp., Tokyo, Japan), All-Bond Universal (Bisco, Inc., Schaumburg, IL, USA) and Single Bond Universal (3M ESPE, St Paul, MN, USA). Adhesives were applied to the specimens and polymerized. A micro-hybrid composite resin (Filtek Z250, 3M ESPE, MN, USA) was then placed on the specimen surfaces and polymerized. Micro-shear bond strengths were tested using a universal testing device (LRX, Lloyd Instruments, Farnham, UK). A Shapiro-Wilk test confirmed normal distribution, and 2-way ANOVA was used for statistical analysis. Result: No significant differences were found in the shear bond strengths of any of the tested adhesives to either of the calcium silicate-based materials (p&amp;gt;0.05). Conclusion: The results indicate that the acidity of a universal adhesive does not affect the bond strength of composite resin to calcium silicate-based materials.

Comparative Study of Chemical and Mechanical Surface Treatment Effects on The Shear Bond Strength of Polyether-Ether-Ketone to Veneering Resin.

To assess the shear bond strength of composite resin to polyether ether ketone (PEEK) after mechanical and chemical surface treatments. A total of 48 PEEK discs were fabricated and divided equally into four surface treatment groups (n = 12 each): (1) airborne particle abrasion with 50-μm alumina particles at 2 MPa pressure for 10 seconds; (2) 98% sulfuric acid etching for 1 minute; (3) airborne particle abrasion and sulfuric acid etching; and (4) no surface treatment. Specimens were conditioned, then Gradia composite veneer (GC) was applied to the PEEK surfaces and polymerized. Bond strength was measured with shear bond test using a universal testing machine. One-way analysis of variance and Tukey post hoc tests were applied for statistical analysis. The mean shear bond strength values of the sulfuric acid-etched group were higher than that of the airborne particle abrasion + acid etching, airborne particle abrasion, and control groups (P < .05). Mean shear bond strength values for the airborne particle abrasion + acid etching samples were higher than for the control and airborne particle abrasion groups (P < .05). There was no significant difference between the samples treated with airborne particle abrasion and the control group.

Shear bond strength of acid and laser conditioned enamel and dentine to composite resin restorations: An in vitro study.

ObjectiveTo compare the shear bond strength of enamel or dentin conditioned with either Er,Cr:YSGG (erbium, chromium: yttrium–scandium–gallium–garnet) laser or phosphoric acid to composite resin restoration.Material and methodsForty posterior human extracted teeth were used. After mesiodistal sectioning of the teeth crowns, the samples were randomly divided into two groups—in the first group (E), bonding was performed on the enamel after roughening and in the second group (D), the enamel was removed and bonding was performed on the dentin. These groups were further randomly divided into two subgroups according to the type of etching (n = 20 each). In the acid‐etched groups (EA and DA), the surfaces were etched with 37% phosphoric acid. In the laser‐conditioned groups (EL and DL), the surfaces were conditioned with Er,Cr:YSGG laser. Total‐etch adhesive system was used to bond all the 80 specimens resin composite. The composite was vertically light‐cured, and the specimens were subjected to a shear bond strength test. Modes of bond failure were determined with a stereomicroscope.ResultsThe highest shear bond strength was observed for the DA group (16.25 ± 1.10 MPa, p < 0.0001), whereas the lowest was observed for the DL group (8.56 ± 0.67 MPa). The adhesive failure mode was the most frequently observed in all groups.ConclusionsThe shear bond strength of composite resin bonded to enamel and dentin etched with phosphoric acid was higher than when conditioned with Er,Cr:YSGG laser. Thus, laser conditioning is not recommended.

Effect of nonthermal atmospheric plasma on the shear bond strength of composite resin after using different tooth-whitening systems: An in vitro study.

Aim:We aimed to evaluate the effect of nonthermal atmospheric plasma (NTAP) on the bond strength of composite resin after using different tooth-whitening systems.Methods:Eighty maxillary central incisors (n = 80) were divided into two groups based on the tooth-whitening procedure used – Group 1: bleaching (Pola Office, USA), Group 2: microabrasion (Opalustre, Australia). The samples were subdivided into four groups depending on the surface treatments – Group A: control (no surface treatment), Group B: plasma, Group C: antioxidant (sodium ascorbate), and Group D: buffering agent (sodium bicarbonate). After the surface treatments, the specimens were stored in artificial saliva for 24 h and composite resin was bonded to the labial surface of the teeth perpendicular to the long axis. The samples were then subjected to shear bond strength test under the universal testing machine.Statistical Analysis:The results received from shear bond strength analysis were subjected to statistical analysis using a two-way ANOVA test, independent t-test, and Tukey's multiple post hoc tests. The P value set was <0.05.Results:The highest mean bond strength value was seen in Group 2B (NTAP treatment after microabrasion) followed by Group 1B (NTAP treatment after bleaching). Mean shear bond strength values have suggested a statistically significant difference between all the other groups (P < 0.05) except between Groups 1A, 2A and 1D, 2D.Conclusions:Within the limitations of the current in vitro study, bleaching and microabrasion followed by surface treatment using NTAP showed the highest bond strength than other groups.

Comparative evaluation of Emblica officinalis as an etchant and an MMP inhibitor with orthophosphoric acid and chlorhexidine on the microshear bond strength of composite resin: an ex vivo study.

ObjectivesThis study aimed to evaluate Emblica officinalis (Indian gooseberry or amla) as an acid etchant and matrix metalloproteinase (MMP) inhibitor, and to compare its effect on the microshear bond strength of composite resin with orthophosphoric acid (OPA) and 2% chlorhexidine (CHX) as an acid etchant and MMP inhibitor, respectively.Materials and MethodsThe etching effect and MMP-inhibiting action of amla on dentin samples were confirmed by scanning electron microscopy (SEM) and gelatin zymography, respectively. Dentinal slabs (3 mm thick) from 80 extracted human molars were divided into 10 and 20 samples to form 2 control groups and 3 experimental groups. Groups 1, 2, and 4 were etched with OPA and groups 3 and 5 with amla juice. An MMP inhibitor was then applied: CHX for group 2 and amla extract for groups 4 and 5. Groups 1 and 3 received no MMP inhibitor. All specimens received a standardized bonding protocol and composite resin build-up, and were subjected to microshear bond strength testing. The force at which the fracture occurred was recorded and statistically analyzed.ResultsAmla juice had a similar etching effect as a self-etch adhesive in SEM and 100% amla extract was found to inhibit MMP-9 by gelatin zymography. The microshear bond strength values of amla were lower than those obtained for OPA and CHX, but the difference was not statistically significant.ConclusionsAmla has a promising role as an acid etchant and MMP inhibitor, but further studies are necessary to substantiate its efficacy.

Reversal of deleterious effect of extracoronal in- office bleaching on shear bond strength of composite resin to bleached enamel: Effect of delayed restoration and different antioxidants application - in vitro study

Objective:The objective of this in - vitro study was to evaluate the effect of different antioxidants in reversal of of deleterious effect of bleaching on shear bond strength of composite resin to bleached enamel.Materials and methods: Seventy bovine incisors were used. The specimens were randomly divided into seven groups (10 specimens each) as follow: Group 1: no bleaching treatment and no antioxidant application. Group 2: bleaching only without antioxidant application and immediate composite resin application after bleaching. Group 3: bleaching only without antioxidant application and delayed composite application (after 2 weeks) of storage. Group 4: bleaching and application of 10% Alpha-tocopherol.Group 5: bleaching and application of 6% cranberry extract. Group 6:bleaching and application of 10% sodium ascorbate. Group 7: bleaching and application of 10% green tea. 40% hydrogen peroxide (Opalescence Xtra Boost 40%, Ultradent, South Jourdan, UT, USA) was used. Composite resin Tetric N -Ceram was used. The shear bond strength was measured using a universal testing machine. Results: one-way ANOVA test revealed significant differences in shear bond strength among the tested groups (p < 0.001). Bond strength significantly decreased after bleaching. There was no significant difference in shear bond strength reversed using10% Alpha-tocopherol, 10% sodium ascorbate and 10% green tea and delayed restoration. Whereas the difference was significant between group 5(6% cranberry extract) and other antioxidants groups. Conclusion: The results obtained from the use of antioxidants using (10% Alpha-tocopherol, 10% sodium ascorbate and 10% green tea extract) is approximately the same as the delayed restoration.

Study on Tensile Bond Strength of Composite Resin for Dental Hard Tissues Irradiated by Er,Cr:YSGG Laser

Study on Tensile Bond Strength of Composite Resin for Dental Hard Tissues Irradiated by Er,Cr:YSGG Laser

Comparative Evaluation of Different Antioxidants on Reversal of Microtensile Bond Strength of Composite Resin in Endodontically Treated Tooth Surface

Introduction: The use of Sodium Hypochlorite (NaOCl) as an endodontic irrigant changes the properties of dentine and lowers the bond strength of resin cements to dentine. But it can be reversed by the use of antioxidants. Aim: To evaluate the effect of different antioxidants for restoring adhesion potential/reversal of microtensile bond strength of dentin of the pulp chamber treated with NaOCl and Ethylenediaminetetracetic Acid (EDTA). Materials and Methods: It was a laboratory based experimentalin-vitro study in which 40 freshly extracted human incisors were selected and cut to expose the pulp chamber dentin. The specimens were distributed into five groups: Group I samples were irrigated with 5.25% NaOCl for 30 minutes followed by 17% EDTA for 3 minutes and final rinse was done with 5.25% NaOCl (Positive control). Group II samples were treated with distilled water only (Negative control). In Group III, samples were treated same as in group I followed by 10% Sodium Ascorbate (SA) for 10 minute. Samples of group IV samples were also treated as in group I followed by application of 5% solution of Alpha tocopherol with for 10 minutes. Group V samples were treated same as in group I followed by rinse with 5% solution of Sodium Thiosulphate (Na2S2O3) for 10 minutes. Composite resin build up was performed and interface was tested by using Universal testing machine for Microtensile bond strength. The resulting data was analysed by one-way Analysis of Variance (ANOVA) and Mann-Whitney U test (p&lt;0.05). Results: The results demonstrated that irrigation with 5.25% NaOCl and 17% EDTA produce significant (p&lt;0.05) reduction in resin dentin bond strength but this can be reversed by application of 5% Na2S2O3. Highest bond strength was observed in group V (22.38±0.84) and lowest for group I (15.38±1.22). Conclusion: Dentin bond strength was significantly reduced when bonding was performed immediately after use of NaOCl. Use of antioxidants after final irrigation with NaOCl can be recommended for better bonding of composite resin.

Effect of Different Cleansing Protocols on Bond Strength of Composite Resin to Dentin Contaminated with Hemostatic Agent: An In Vitro Study.

Objectives:Inadequate removal of the hemostatic agent can adversely affect the bond strength of restorations to the tooth structure. This study aimed to assess the effect of different cleansing protocols on the shear bond strength (SBS) of an etch-and-rinse adhesive to dentin contaminated with aluminum chloride hemostatic agent.Materials and Methods:In this experimental study, the mid-coronal dentin of 96 premolars was exposed. They were contaminated with a hemostatic agent (ViscoStat Clear) and then randomly divided into 7 groups (n=12). One group served as the control. The groups underwent various cleaning methods as follows: water spray, aluminum oxide particles (27μ diameter), a slurry of pumice with water, GC dentin conditioner (GCDC), sodium hypochlorite 2% (SHC), and chlorhexidine 2% (CHX). Composite cylinders were then fabricated and bonded to the surfaces using Scotchbond Multi-Purpose etch-and-rinse bonding agent. After thermocycling (10,000 cycles), the SBS was measured using a universal testing machine. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey HSD (honestly significant difference) test, and the significance level was set at 0.05.Results:The SBS of the groups was significantly different (P=0.036). The SBS was the highest in the CHX and SHC groups, and the lowest SBS was related to the control group and GCDC groups. The difference between other groups was not significant (P=0.996).Conclusion:CHX and SHC yielded the highest bond strength among the tested modalities for cleansing the ViscoStat Clear from the tooth surface.