Bond Strength Of Composite Resin Research Articles

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.

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.

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.

Evaluation of Shear Bond Strength of Composite Resin to Dentin after Etching with Er,Cr:YSGG Laser And Conventional Acid Etch (An In Vitro Study)

The aim of this study was to evaluate shear bond strength of composite to dentin after etching with conventional acid, Er,Cr:YSGG laser and Er,Cr:YSGG laser in conjunction with acid. Thirty recently extracted lower third molars were collected. Scaling and polishing of teeth were done. Roots of teeth were embedded inside self cured acrylic resin blocks to form acrylic base with occlusal surfaces parallel to base of blocks. Crowns of teeth were sectioned at one third of the crowns to obtain a flat dentin surfaces. Total number of samples were divided into 3 groups each of one contained (10) samples as following : Group 1- dentin surfaces were treated with 35% phosphoric acid only. Group 2- dentin surfaces were treated with Er,Cr:YSGG laser only. Group 3- dentin surfaces were initially treated with Er,Cr:YSGG laser, then with 35% phosphoric acid. Bonding agent was applied to dentin surfaces and composite was applied by using rubber mold then light cured. Composite posts were released from molds then shear bond strength was measured. Statistical analysis showed that there was significant difference among all groups and acid etching group showed significant highest Shear bond strength followed by group of laser &amp; acid etching then group of laser etching showed the significant least shear bond strength. From this study it can be concluded that etching of dentin with Er,Cr:YSGG laser can produce shear bond strength weaker than that of conventional acid etching.

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.

Effect of green tea extract antioxidant on dentin shear bond strength and resin-tag penetration depth after non-vital bleaching

Background: 35% Hydrogen peroxide (H2O2) as an active material for internal bleaching produce free radicals that can affect the adhesive system. Application of 10% and 35% green tea (GT) extract as an antioxidant after 2 minutes are expected can remove free radical residues. The aim of this study is to evaluate the effect of 10% and 35% GT extract after 2 minutes of application on dentin shear bond strength and resin tags penetration depth after non-vital bleaching. Methods: The crown part of 30 extracted healthy human premolars were cut horizontally 2 mm from the cementoenamel junction, then split in mesio-distal direction. The specimens were divided into five groups: normal dentin, post-bleaching dentin, delayed 2 weeks, 10% GT, and 35% GT group. Non-vital walking bleach with 35% H2O2 gel was done to all groups except control group. Soon after, 10% and 35% GT extract gel were applied on dentin for 2 minutes, then the specimens were rinsed off with distilled water for 2 minutes and dried. All specimens were etched and bonded with an etch-and-rinse adhesive system and filled with resin composite. The shear bond strength assessment was done using a Universal Testing Machine with a cross-head speed of 0.5 mm/minute. Confocal laser scanning microscopy with a wavelength of 560 nm and a lens magnification of 40x was used to analyze the resin tag penetration. Data were analyzed by one-way ANOVA. Results: There was a significant difference in resin tag penetration depth and shear bond strength between 10% and 35% GT group (p &lt; 0.05). The 35% GT group resulted in a significantly longer resin tag penetration than the 10% GT group. Conclusions: The application of 35% GT extract is more effective than 10% GT extract as an antioxidant for increasing the shear bond strength of composite resin after internal bleaching.

Effect of Internal Bleaching on the Microshear Bond Strength of Composite Resin to Dentin in Recently Restored Teeth

Background: This study aimed to assess the effect of internal bleaching on the microshear bond strength of composite resin to dentin in recently restored teeth.&#x0D; Methods: This in vitro, experimental study evaluated 40 sound human premolars. The teeth were sectioned below their cementoenamel junction. Access cavity was prepared, pulpal tissue was removed and filled with glass ionomer. The teeth were then randomly divided into 4 groups. In the control group, no internal bleaching was performed and dentin surface was restored with composite. In group 2, internal bleaching with 35% hydrogen peroxide (Opalescence, ultradent) was performed 4 weeks after composite restoration. Bleaching was performed immediately after restoration of teeth in groups 3 and 4. Teeth were etched with 35% phosphoric acid for 15 seconds, rinsed, dried, and primer and adhesive (Adper Scotchbond Multipurpose) were applied. The teeth were then restored with Z250 (3M ESPE) microhybrid resin composite. Teeth were sectioned into 1 mm2 sections and underwent micro-shear bond strength test. In groups 1 to 3, bond strength was measured after 24 hours while in group 4, it was measured after 1 month. Data were analyzed using one-way ANOVA.&#x0D; Results: The mean micro-shear bond strength of composite to dentin was maximum in group 2 and minimum in group 3. However, the difference in this respect was not significant among the groups (p&gt;0.05).&#x0D; Conclusion: In teeth requiring immediate esthetic restorations, treatments can be performed after non-vital bleaching with no time restriction and adequately high bond strength comparable to non-bleached teeth.

Effect of green tea extract antioxidant on dentin shear bond strength and resin-tag penetration depth after non-vital bleaching

Background: 35% Hydrogen peroxide (H2O2) as an active material for internal bleaching can produce free radicals that can affect resin tag penetration into the dentinal tubules. Application of 10% and 35% green tea (GT) extract as an antioxidant after 2 minutes are expected to remove free radical residues and increase dentin shear bond strength and resin tags penetration depth after non-vital bleaching. Methods: 30 extracted healthy human premolars were cut horizontally 2 mm from the Cemento Enamel Junction margin to the crown part, then cut in a mesio-distal direction into two parts. The specimens were divided into five groups: normal dentin, post bleaching dentin, delayed 2 weeks, 10% GT, and 35% GT group. Non-vital walking bleach with 35% H2O2 gel was done to all groups except control group. Soon after, 10% and 35% GT extract gel were applied on dentin for 2 minutes, then the specimens were rinsed-off with aquabidest for 2 minutes and dried. All specimens were etched and bonded with an etch-and-rinse adhesive system and filled with resin composite. The shear bond strength assessment was carried out using a Universal Testing Machine (UTM) with a cross-head speed of 0.5 mm/minute. Confocal laser scanning microscopy (CLSM) with a wavelength of 560 nm and a lens magnification of 40x was used to analyze the resin tag penetration. Data were analyzed by one way ANOVA and t-test. Results: There was a significant difference in resin tag penetration depth and shear bond strength between applying 10% and 35% GT extract (p &lt; 0.05). The 35% GT extract group resulted in a significantly longer resin tag penetration than the 10% GT extract group. Conclusions: The application of 35% GT extract is more effective than 10% GT extract as an antioxidant for increasing the shear bond strength of composite resin after internal bleaching.

The effect of propolis on the bond strength of composite resin to enamel after intracoronal bleaching with different bleaching agents.

This study evaluated the effect of propolis as an antioxidant agent on bond strength to enamel after intracoronal bleaching. A total of 160 incisors were endodontically treated. Sixteen teeth were served as control, and the remaining teeth were randomly divided into three main groups according to the bleaching agent used; group 1: Sodium perborate (SP); group 2: Carbamide peroxide (CP); group 3: Hydrogen peroxide (HP). After bleaching, the samples were divided into three subgroups; subgroup A: no antioxidant agent application, subgroup B: sodium ascorbate (SA), subgroup C: propolis (PP). After the antioxidant agents application, the sample's surfaces were washed and dried. After adhesive application, composite resin cylinders were applied to enamel surfaces using tygon tubes and a shear bond strength test was performed. The use of PP significantly decreased the bond strength of composite resin to the enamel (p < 0.05). Using propolis as an antioxidant agent adversely affects the bond strength to enamel after intracoronal bleaching.

Comparative Evaluation of Effect of Different Antioxidants on Shear Bond Strength of Composites on Bleached Enamel: An In Vitro Study.

To evaluate the effect of antioxidants on the shear bond strength of composite resin to bleached enamel. A total of 120 extracted permanent anterior teeth were split into four major groups, one among them being a control group. Group I (bleaching + without antioxidant), group II (bleaching + 10% sodium ascorbate), group III (bleaching + 5% grape seed extract), and group IV (bleaching + 5% pine bark extract). All of the groups were bleached using a gel containing 35% carbamide peroxide, and then they were divided into two subgroups depending on when the bonding operation was to be completed-subgroup A was done in 24 hours, while subgroup B took 3 weeks. The universal testing machine was used to measure the shear bond strength. Subgroup IA showed poor shear bond strength than other groups, there was no statistically significant difference between subgroup IB, IIA, and IVA. Subgroup IIIA showed the highest shear bond strength than the remaining groups. Between subgroups IIA and IIB, IIIA and IIIB, and IVA and IVB there was no statistically significant difference. This shows that delaying the bonding procedure for 3 weeks shows similar shear bond strength when compared to groups that were immediately bonded after antioxidant applying groups. All the antioxidants' immediate application could reverse compromised bond strength. Among them, 5% grape seed extract shows the highest increase in shear bond strength. Maddula DC, Vasepalli M, Martha S, et al. Comparative Evaluation of Effect of Different Antioxidants on Shear Bond Strength of Composites on Bleached Enamel: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(1):87-92.

Bond Strength of Composite Resins used in the Repair of all Ceramic and Metal Ceramic Crowns - An In vitro Study

Bond Strength of Composite Resins used in the Repair of all Ceramic and Metal Ceramic Crowns - An In vitro Study

Repair bond strength of different CAD-CAM ceramics after various surface treatments combined with laser irradiation.

The aim of this study was to evaluate the effect of different surface treatments combined with laser irradiation on the shear bond strength of different CAD-CAM ceramics to composite resin. A total of hundred forty-seven ceramic specimens with thicknesses of 2.5mm were prepared from three different CAD-CAM ceramics (an yttrium oxide partially stabilized tetragonal zirconia polycrystal (Y-TZP); a zirconia-reinforced lithium silicate glass ceramic (ZLS); and a lithium disilicate-strengthened lithium aluminosilicate glass ceramic (LD-LAS)) and subjected to seven groups of treatment (n = 7): (1) control (no treatment), (2) Er:YAG laser irradiation, (3) Nd:YAG laser irradiation, (4) etching with hydrofluoric acid (HFA), (5) Er:YAG + HFA, (6) Nd:YAG + HFA, and (7) sandblasting. After surface treatment procedures, a ceramic primer (Clearfil Ceramic Primer Plus, Kuraray, Japan) was applied to the ceramics. Bonding agent (Single Bond Universal Adhesive, 3M ESPE, USA) was then applied, and the composite resin (Estelite Sigma Quick, Kuraray, Japan) was layered on the ceramic surfaces. The shear bond strength test was performed using a universal testing machine at a load of 0.5mm/min. Data were analyzed by 2-way analysis of variance (ANOVA), and the Bonferroni correction was used for pairwise comparisons (α = 0.05). Compared to the bond strength of the control group, irradiation by Er:YAG and Nd:YAG lasers alone improved the bond strength of the composite resin to the Y-TZP (P < 0.001) but did not change the bond strength of composite resin to the ZLS and LD-LAS (P > 0.05). Compared to the bond strength of the control group, etching with HFA alone increased the bond strength of the composite resin to the ZLS and LD-LAS (P < 0.001) but did not affect the bond strength of the composite resin to the Y-TZP (P > 0.05). The highest bond strength of ZLS was obtained using HFA + Er:YAG, and the highest bond strength for LD-LAS was obtained using HFA + Nd:YAG. It was concluded that Er:YAG and Nd:YAG laser treatments presented the highest repair bond strength between the composite resin and Y-TZP ceramics. Er:YAG and Nd:YAG laser treatments in conjuction with HFA presented the highest repair bond strength between the composite resin and the glassy ceramics, ZLS, and LD + LAS.

Effect of nonthermal atmospheric plasma on bond strength of composite resin using total-etch and self-etch adhesive systems.

The aim of this study was to assess the impact of nonthermal atmospheric plasma (NTAP) on the bond strength of composite resin following plasma application at different steps of dentin bonding in total-etch and self-etch adhesive systems. Ninety extracted third molars were taken, and the occlusal surfaces were removed until the exposure of the dentin. Samples were distributed into two main groups: Group T: total-etch adhesive system and Group S: self-etch adhesive system. Groups are further subdivided (n = 10) based on plasma application at different steps of dentin bonding. T1: surface etching with 37% phosphoric acid and bonding agent application. T2: plasma application and bonding agent application. T3: plasma application, etching, and bonding agent application. T4: etching, plasma application, and bonding agent application. T5: etching, plasma application, bonding agent application, and again plasma application. S1: self-etch bonding agent application. S2: plasma application and bonding agent application. S3: Bonding agent application and plasma application. S4: plasma application, bonding agent application, and again plasma application. For all the samples, composite resin buildup was done, and shear bond strength (SBS) was measured. The contact angle was measured at different steps of dental adhesive systems. Two-way analysis of variance and the post hoc Tukey's test were used for analysis, regarding P < 0.05 as statistically significant. Among all groups of total-etch and self-etch adhesives, Group T4 (48.81 Mpa) and Group S2 (36.59 Mpa), respectively, have demonstrated significantly greater bond strength values than the corresponding control groups. NTAP enhanced the composite resin's SBS when plasma treatment was done before bonding agent application and significantly reduced the contact angles of the distilled water.

Comparison of shear bond strength of composite resin, compomer, and resin-modified glass-ionomer cements in primary teeth: An in-vitro study.

The contemporary esthetic restorative materials such as composite resin and glass-ionomer cements and their modifications have all been developed keeping in mind the requirements of permanent teeth. There have been plenty of studies that have focused on the characteristics of these materials in relation to permanent teeth with a relative dearth of such studies as regard to the primary teeth. The present study was undertaken to compare and evaluate the shear bond strength of composite resin, compomer, and resin-modified glass-ionomer cements in primary teeth. Thirty non-carious primary molars that were indicated for extraction because of physiological resorption or, for orthodontic reasons, were selected. The selected teeth were randomly allocated to three groups of 10 each for composite, compomer, and resin-modified glass-ionomer cements. The enamel from the occlusal surface of all teeth was removed to expose the superficial dentin and was wet polished with 400 grit sand paper. Composite, compomer, and resin-modified glass-ionomer stubs were bonded on to the occlusal surfaces using a plastic tube as a template. All samples were, then, subjected to thermocycling and evaluation of shear bond strength using the universal testing machine at a cross-head speed of 0.5 mm/min, whereas the results obtained were subjected to statistical analysis. Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) version 17.0 (SPSS Inc., Chicago, IL, USA), whereas one-way analysis of variance (ANOVA) and Tukey's multiple post-hoc procedures were used for statistical analysis. A P < 0.05 was considered statistically significant. The mean shear bond strength values for Groups I, II, and III were found to be 11.7 ± 3.07 MPa, 7.74 ± 4.16 Mpa, and 4.43 ± 2.08 Mpa, respectively, whereas one-way ANOVA and Tukey's multiple post-hoc procedures indicated that there were remarkable differences among the three groups with the results being statistically significant (P < 0.05). Composite resin showed the highest shear bond strength in relation to primary dentin when compared to compomer and resin-modified glass-ionomer cements.

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.

Repair strength of dimethacrylate-based composites resins: Effect of sandblasting, adhesive bonding, and thermocycling

Background: The goal of this study is to determine the effect of different sandblasting particles and dental adhesive systems on the repair strength of dimethacrylate-based composite resins. Materials and Methods: In this in-vitro study, 96 specimens of X-trafil composite blocks were prepared and divided into eight groups (n = 12). Four groups were sandblasted with Aluminum Oxide (AL) and four other groups with Bio-Active Glass particles (BAG). A two-component silane was applied on the surface of all the samples after phosphoric acid etching and rinsing. Two groups of the sandblasted specimens were treated with Clearfil SE Bond (CSB) and the other two groups were treated with Single Bond Universal (SBU) and new composite was bonded to the prepared surfaces. Half of the specimens in each group were thermocycled. Shear force was applied to the bonded composite using a universal testing machine with a crosshead speed of 0.5 mm/min and mean shear bond strength (MSBS) was calculated (MPa). The data was analyzed using Kruskal–Wallis and Man–Whitney U-tests with the significance level of 0.05.Results: Significant differences were observed between different groups (P < 0.001). The highest and the lowest MSBS of the thermocycled samples were reported 18.88 MPa with application of AL and SBU and 11.46 MPa with the application of AL and CSB, respectively. No significant difference was observed with application of BAG particles after thermocycling.Conclusion: Effect of AL on repair shear bond strength of composite resins is affected by bonding type. Bonding type did not affect repair shear bond strength of BAG. Thermocycling reduced bond strength in all groups.