SBS Test Research Articles

In Vitro Investigation of the Effect of Silanizing on the Repaired Bond Strength of Short-Fiber Composites Subjected to Surface Treatment with an Er;Cr:YSGG Laser, Sandblasting, or Bur

Background: This study aimed to evaluate the effect of various interfacial surface treatments on the repair micro shear bond strength (μSBS) of aged short fiber-reinforced composite (SFRC). Methods and Materials: The substrate and repair composite material used in the fabrication of eighty samples were SFRC (Ever-X posterior, GC). Based on the mechanical roughening method, the samples were divided into four categories: diamond bur, sandblasting, laser treatment, and a control group. Then, they were split into two groups using the chemical conditioning method: those using a universal glue that contains silane and those using a separate silane step before the universal adhesive that contains silane. After 40 days of immersion in distilled water at 37°C, the specimens were removed. Universal testing equipment was used to implement SBS testing. Using field emission scanning electron microscopy (FESEM), the surface topography of the composite material was examined after the roughening procedures. Results: Although the laser group had the highest μSBS value, there was no statistically significant difference in μSBS across the groups (P > 0.05). The results for μSBS were also not significantly different when using universal adhesive with or without an extra silanizing step (P > 0.05). Conclusion: Based on the results, the other groups' μSBS values were lower than those of the laser group. Incorporating a distinct silanization process before applying the universal adhesive that contained silane did not improve the μSBS either.

Orthodontic Bracket to Enamel Pretreated With Nd: YAG and Er: Cr, YSGG Lasers Using Curcumin-Hydroxyapatite Nanoparticles Infused Adhesive: A FTIR, SEM Evaluation via Backscattered Electron Imaging.

To evaluate the SBS, DC, and rheological valuation of experimental 1 wt % Cur-loaded-HNPs orthodontic adhesive to bond bracket to enamel surface treated with PA; Nd: YAG, and Er: Cr, YSGG lasers. Two adhesives were prepared experimental adhesive (EA) and EA loaded with 1-wt % Cur-HNP. Surface characterization of Cur-loaded HNP was performed under SEM along with EDS. Specimens were prepared and conditioned with three different strategies PA-gel, Er,Cr:YSGG laser, Nd: YAG laser. Following pretreatment brackets were bonded, samples underwent artificial aging and two samples from each enamel pretreatment regime were assessed under SEM via BSE. SBS testing was achieved via UTM followed by failure analysis using ARI. Modified and unmodified adhesives underwent DC using FTIR and rheological valuation was performed. SBS and DC were assessed using ANOVA and post hoc multiple comparison tests. The highest SBS was seen in the enamel surface treated with PA. The lowest SBS was remarked in the enamel surface treated with Nd: YAG laser. Based on ARI it was noted that modified adhesive containing Cur-HNP exhibited the highest number of failures between 1 and 2. No significant difference was observed between both adhesives in terms of DC. Adhesive modified with 1% Cur-HNP increased viscosity with a decrease in fluidity. The use of Er,Cr:YSGG laser for enamel pretreatment before bracket placement showed potential as a substitute for conventional acid etching, especially when combined with an experimental orthodontic adhesive containing Cur-HNPs.

THE STUDY OF SBS IN BUILDINGS – IMPACT ON HEALTH AND TECHNOLOGICAL SOLUTION

Sick Building Syndrome is a condition whereby occupants of a building experience sicknesses that can be linked to the amount spent in that particular building. The end users experience unhealthy mild or sometimes severe symptoms or fall sick with such conditions as allergies as well as irritations of the throat, eyes, nose and also lethargy and sometimes dizziness Mølhave (1989). Unlike Building-related illnesses (BRI), SBS has no identifiable cause. In 1984, the World Health Organization (WHO) estimated that 30% of new and remodelled buildings worldwide may have SBS. This study will analyze the severity of SBS in North Cyprus based on different building elements and how they support the development of SBS in a building. Part of the outcome of this work is to develop a framework to test the level of SBS in a residential building by testing how occupants react to the building and demonstrating that building design elements such as orientation, roofing insulation systems, roof installations, and thermal floor masses alter the SBS effect on occupants. The goal is to develop "SBS TEST SOFTWARE" to assist professionals in assessing the SBS level in a building utilizing direct interview software, which can readily identify SBS-prone structures in Cyprus and worldwide. Cyprus’ SBS difficulties can be attributed to several design flaws in building elements, improper ventilation, uneven or inadequate heat distribution, and a lack of moisture-proofing of roof decks, walls, and foundations Obi (2016).

Recycling CAD/CAM Lithium Disilicate Ceramic: Effect of Surface Treatment and Aging on the Bond Strength to Resin Cement.

To investigate the effects of recycling lithium disilicate (LD), surface treatment, and thermocycling on the bond strength to resin cement. A total of 72 tablets (10 × 10 × 3 mm) of LD were made according to the recycling cycle with 24 tablets for each strategy: control (conventional sintering), 1R (1 recycling cycle), and 3R (3 recycling cycles). For the recycling groups, tablets were waxed, mounted in a silicone ring, and poured with investment material, and residues of sintered LD tablets were pressed by the lost wax technique. The residual LD was reused as described until it reached 3R. Afterward, the tablets were embedded in acrylic resin, sanded, and divided (n = 15) according to the factors of 'surface treatment' (hydrofluoric acid [HF] for 20 seconds [HF20s] and silane, HF for 120 seconds [HF120s] and silane, and Monobond Etch & Prime [MEP]) and thermocycling (TC; with 10,000 cycles and without). After surface treatment, cylinders (diameter: 2 mm) of resin cement were made and submitted to SBS test (100 kgf, 1 mm/minute). Data (MPa) were analyzed by three-way ANOVA, Tukey test (5%), and Weibull analysis. Failure analysis was performed with a stereomicroscope. ANOVA revealed that all factors were significant (P = .000*). The group 3RMEP (105.09 ± 19.49) presented the highest SBS among the experimental groups. The 1RHF20sTc (7.50 ± 1.97) group had the lowest SBS, similar to CHF20sTc (15.69 ± 3.77), 1RHF20s (15.12 ± 3.03), 1RHF120sTc (14.60 ± 3.43), and 3RHF20sTc (15.65 ± 0.97). The Weibull modulus and characteristic strength varied among the experimental groups (P = .0). Failure analysis revealed adhesive and mixed types. The recycling of DL ceramics increases the SBS to resin cement when the ceramic is treated with HF120s and silane or MEP.

Caries affected disinfection using Phycocyanin activated by PDT, Holy Basil, and Ti-sapphire laser on adhesive bond strength, microleakage, and bond failure

AIMTo investigate the effect of different cavity disinfectants, Phycocyanin (PC), Ocimum Sanctum (OS), and Ti Sapphire Laser, on the bond integrity and microleakage of resin restorations. Material and method60 human mandibular molars were extracted and prepared based on ICDAS scores of 4 and 5. To obtain the CAD surface, a visual examination was supported by tactile sensation and a dye for caries detection. Samples were randomly allocated into 4 groups based on cavity disinfectants applied (n = 15). Group 1: Specimens disinfected with CHX, Group 2: Specimens disinfected with Ti sapphire laser, Group 3: Specimens disinfected with Phycocyanin activated by Photodynamic therapy, and Group 4: Specimens disinfected with OS. Following the disinfection of the CAD surfaces, composite bulk-fill restorative material was bonded to each specimen and all samples were subjected to thermocycling. Ten samples from each group underwent SBS testing performed on a universal testing machine. Five samples were subjected to a microleakage analysis. ResultThe maximum microleakage scores were displayed by Group 3: PC (0.521 nm) treated specimens. Whereas, and minimum microleakage was exhibited by Group 4: OS (0.471 nm). Group 4: OS (23.06±0.21 MPa) treated group displayed the maximum bond scores of resin adhesive to the CAD surface. However, Group 3: PC (21.67±0.24 MPa) treated specimens exhibited the lowest bond scores. Failure mode analysis revealed that among all the investigated groups the predominant type of failure was cohesive failure i.e., Group 1 (80%), Group 2 (80%), Group 3 (70%), and Group 4 (90%). ConclusionOcimum Sanctum, Phycocyanin activated by Photodynamic therapy, and Ti-sapphire laser for disinfection of caries-affected dentin have shown promise in terms of improved bond strength and reduced microleakage

Effect of Photo-polymerization Delay on the Bond Strength and Microhardness of Dual-polymerizing Resin Cements.

To fully maximize the potential of dual-polymerizing resin cements, a thorough understanding of how the light- and chemical-polymerizing components interact in a resin system is required. Disorder in the polymerization process between the two components may hurt one of the components versus the other, affecting the overall properties and performance of the resin cements. Evaluate photo-polymerization delay time on dentin shear-bond strength and Vickers microhardness of dual-polymerizing resin cements. Shear bond strength (SBS) of self-adhesive (RelyX Unicem 2, 3M ESPE) and adhesive (RelyX Ultimate, 3M ESPE) dual-polymerizing resin cements were evaluated. Dentin specimens (n=80) were prepared for the SBS test according to ISO standard 29022:2013. Teeth were randomly allocated into eight groups based on the type of cement, and photo-polymerization delay times (0, 2, 5, and 10 minutes). Vickers microhardness test (HV) was performed following ASTM E384-17 (n=32) prepared based on cement type and photo-polymerization delay times; specimens were tested after 24 hours of storage. Statistical analysis was performed using two-way ANOVA to determine the individual and combined effects of resin cement type and photo-polymerization delay time on SBS and HV. Resin cement and photo-polymerization delay times for the adhesive cement at 0- and 2-minute pairings had significantly higher SBS means than all other combinations (p<0.0001). Resin cement type was also statistically significant (p<0.0001). Resin cement type and photo-polymerization delay times were not significant (p=0.3550) for HV. Photo-polymerization delay time affected dentin SBS with higher bond strength when photo-polymerization delay time was performed between 2 and 5 minutes with a self-adhesive resin cement, and between 0 and 2 minutes with an adhesive resin cement. Delaying photo-polymerization time to 10 minutes led to inferior dentin SBS and HV for both self-adhesive and adhesive dual-polymerizing resin cements.

Bond Strength of Porcelain Fused to Casting and Selective Laser Base Metal Alloy with a Bonding Agent

Purpose: The goal of this study was to assess how different bonding agents affected the shear bond strength of a feldspathic ceramic fused with a cobalt-chromium alloy that was manufactured using two different techniques: lost wax and a 3D printer. Approach: A total of 40 disks of the cobalt-chromium alloy were made by using casting (Co–Cr) as the control group (n=20 specimens) and additive manufacture by selective laser melting. SLM from Co–Cr (n=20 specimens) the disks were airborne particles abraded with110 µm aluminum oxide particles, then two main groups separated into subgroups based on the type of bonding agent used (with and without addition). shear bond strength was used, before the SBS test the metal and ceramic interfaces were examined using test scanning electron microscopy (SEM). The elemental makeup of the bonding agents was determined using an energy-dispersive X-ray spectroscopy (EDS) test. The results of the SBS tests as well as the failure modes were noted. Data were analyzed using the Least Significant Difference (LSD) test (a = 0.05). Result: Bond strength was much stronger in Co-Cr specimens with bonding agents than in Co-Cr specimens without bonding agents. The mass quantities of silicon (Si) and some titanium (Ti) on the surfaces of alloys varied depending on the production method and the presence of a bonding agent. Conclusion: By use of a bonding agent on various Co-Cr metals improves bond strength with ceramics.

Etch-mineralizing treatment to improve dentin bonding

Objectives This study aimed to investigate the effect of etch-mineralizing solution as a dentin treatment agent on dentin bonding.Methods This study designed four kinds of etch-mineralizing solutions (EMs) by adding sodium fluoride in 35% phosphoric acid aqueous solution with four different concentrations (5, 10, 20, and 30 mg/ml), and named F1, F2, F3 and F4, respectively. 35% phosphoric acid gel treatment was the control group. SEM, EDS, FTIR and microhardness tests were performed on the treated dentin. Shear bond strength was measured before and after aging. Nanoleakage was also evaluated. Fracture mode was researched after SBS testing. The antibacterial properties of treated dentin were also investigated through live/dead staining of biofilms.Results The smear layer was removed and mineralization substances were observed on the dentin surface and tubule, and no obvious collagen fibers were observed compared with the control group. FTIR spectrums showed that the ratios of phosphate/collagen on EMs treated dentin surfaces were significantly increased (P < 0.05). F2 group had the highest bonding strength (32.14 ± 7.33 MPa) and microhardness (66.08 ± 10.58), while the control group had the lowest bonding strength (21.81 ± 4.03 MPa) and microhardness (42.34 ± 7.08) (p < 0.05), and excellent bonding strength caused more cohesive fracture. Experimental groups showed less nanoleakage than group C (P < 0.05). Moreover, experimental groups had better antiaging performance and antibacterial properties than the control group (p < 0.05).Conclusion EMs treatment not only improved dentin bonding and antibacterial ability, but also remineralized dentin with autologous mineral elements.Clinical significance The treatment provides a novel therapeutic strategy for obtaining ideal dentin bonding strength and prolonging the longevity of the restoration.

To evaluate effect of three different reducing agents in recovery of bond strength to sodium hypochlorite treated dentin with composite resin

Background: Endodontically treated teeth lose a large proportion of their structure due to trauma and caries and during endodontic treatment. As a result, they have low physical properties, fracture resistance, and esthetic appearance. The study aims to evaluate the anti-oxidant efficacy of sodium thiosulphate, citric acid and gallic acid on the recovery of shear bond strength to pulp chamber dentin treated with NaOCI &amp; EDTA. Methodology: 50 single rooted second premolars were divided into 5 groups (n=10); Positive control received no treatment; negative control received only irrigation treatment, while the other two experimental groups were treated with their respective anti-oxidant following the irrigation. All the samples were then cured with composite and subjected to SBS test under a universal testing machine. Statistical analysis: ANOVA &amp; Post hoc tukey were used with P &lt;0.5. Results: Anti-oxidant groups showed a greater mean SBS value than the negative control, comparable to positive control. The sodium thiosulfate group showed the highest value with a significant difference from the negative control group. Conclusion: Both the anti-oxidants used were able to restore the Shear bond strength of pulp chamber dentin altered due to endodontic irrigants. Hence, possesses great potential in its clinical implication.

Efficacy of chlorhexidine, photosensitizers, green tea extract, and propolis on bond integrity and microleakage of caries-affected dentin: An in-vitro study

AimThe current study aimed to evaluate the efficacy of chlorhexidine (CHX), phycocyanin photosensitizer (PC), green tea extract (GTE), and propolis (PP) on the adhesive bond integrity and microleakage of caries-affected dentin (CAD) using etch and rinse adhesive system. Material and methodsA sum of 80 extracted human mandibular molars was collected and assessed using ICDAS criteria. Randomly CAD samples were treated with different disinfectants (n = 20) each CHX, PC, GTE, and PP. After ensuring disinfection, specimens were rehabilitated with bulk-fill composite resin employing etch and rinse adhesive system. SBS testing was performed by engaging (n=10) specimens in a universal testing machine. Microleakage analysis was performed by using the dye penetration technique.A stereomicroscope under 40× magnification was utilized for analyzing failure modes. Statistical analysis was accomplished by using the ANOVA and Tukey's post hoc tests (p<0.05). ResultsHighest bond strength was displayed by CAD disinfection with CHX and bonded to resin cement (15.33 ± 0.14 MPa). Whereas, the lowest SBS bond value was presented by Group 2 dentin surface disinfection with PC. CAD disinfected with GTE, PP and CHX demonstrated comparable SBS(p>0.05). The maximum microleakage score was exhibited when CAD bonded to resin cement disinfected with PP. While the minimum microleakage score was unveiled CAD bonded to resin cement sanitized with CHX ConclusionCaries-affected dentin bonded to resin cement, chlorhexidine exhibited the highest adhesive shear bond strength with a minimal microleakage score using etch and rinse adhesive system.

Effect of two hemostatic agents containing Aluminium chloride and ferric sulfate on bond integrity of resin-modified glass ionomer cement

ObjectiveTo evaluate the influence of hemostatic agents (Expasyl and Viscostat) on the bond values of RMGIC bonded to pretreated dentin surface with cavity conditioner (CC), self etch primer (SEP), and antimicrobial photodynamic therapy (aPDT) Materials and methodsOne hundred and eighty human third molars were embedded in a self-cure acrylic resin-filled polyvinyl cylinder. The dentinal surface was prepared and all the samples were arbitrarily distributed into three different groups liable to the hemostatic agent used (n = 60). Samples in group 1: no hemostatic agent used, Group 2: Samples exposed to Expasyl, and group 3: Viscostat. After applying the hemostatic agent, all the samples were surface treated with different surface conditioners. Subgroup A1, B1, C1 were conditioned with aPDT, Subgroup A2, B2, and C2 surface were treated with SEP, and Subgroup A3, B3, and C3 were smeared with CC. RMGIC was placed and SBS was assessed using a universal testing machine and failure mode analysis was performed using and stereomicroscope at 40x magnification. Analysis of variance (ANOVA) and Tukey's post hoc test compared the means and standard deviations (SD) following SBS testing (p = 0.05). ResultsHighest SBS was exhibited by group A2 (22.36 ± 1.66 MPa Control - SEP) whereas group A1 (14.14 ± 1.32 aPDT + Control) demonstrated the lowest SBS. Subgroups B1 (17.23 ± 0.33- Expasyl + aPDT) and C1 (18.36 ± 0.25 MPa -Viscostat + aPDT) were found to be comparable (p > 0.05). Similarly, A3 (19.69 ± 1.01- Control + CC) and B3 (18.23 ± 0.33 MPa- Expasyl + CC) and C3 (18.36 ± 0.37 Viscostat + CC) demonstrated no significant difference in bond scores (p > 0.05). Most of the failures in aPDT were adhesive. However, SEP and CC groups demonstrated admixed and cohesive failure ConclusionDentin conditioned by aPDT after hemostatic agents improves bond values of RMGIC. Self etch Primer and Cavity conditioner using polyacrylic acid without hemostatic agent improves bond integrity of RMGIC.

Shear Bond Strength of a Multi-Mode Universal Adhesive Containing Hydroxy-Apatite Nanoparticles to Dentin (In vitro study)

Aim: To evaluate the effect of addition of Hydroxyl-Apatite nanoparticles to a commercial universal adhesive on sheer-bond-strength to dentin using two application modes, immediately and after thermocycling. Methods: A-commercial UA was used for bonding composite-resin to dentin and considered as control. 10% of HAp were prepared and added to the commercial UA and considered as experimental. 88-freshly extracted sound human premolar teeth were sectioned to expose mid-coronal-dentin. Samples were y divided into: control and experimental group. Each group was further divided based on the application protocol. Half of the samples were stored in distilled water for 24h at 37°C for immediate SBS testing whereas the other half was subjected to thermocycling for 20,000 cycles. SBS was measured one-day post polymerization and after thermocycling using universal testing machine. SBS values and failure modes were recorded and statistically analyzed. Results: the experimental group presented significantly lower resin-dentin SBS than the control group. Thermocycling significantly lowered SBS values for both groups. When using SE mode, the experimental group reported lower resin-dentin SBS than the control group before and after thermocyclying. When using ER mode before thermocycling, no significant difference was found between the two groups, while after thermocycling, the experimental group reported significantly higher resin-dentin SBS than the control group. For both adhesive groups, mixed failure dominated with ER mode while adhesive failure dominated with SE mode. Conclusions:Addition of HA may provide resistance to degradation and offer a potential to improve resin-dentin bond stability against thermal changes when ER protocol is applied.

Influence of Photodynamic therapy and different gingival retraction agents on bond integrity of composite to dentin

The present study was undertaken to evaluate the influence of gingival retraction agents (Expasyl and Viscostat) and different conditioning methods (Total-etch, Self-etch, and PDT) on bond integrity of composite to dentin. One hundred and eighty, third molars were collected cleaned and disinfected in thymol solution. The specimens were rooted vertically up to cementoenamel junction within polyvinyl cylinders (PVC). Based on gingival retraction materials samples were divided into three groups (n = 60). Group A: dentin applied with Expasyl; Group B: Viscostat was applied on dentin and Group C: Control. Dentin surface was treated with different surface conditioners. Etch and rinse, PDT MBP, and Two-step self-etch. A bonding agent was applied and composite buildup was done. Samples were placed in the universal testing machine for SBS. Bond failure was assessed using a stereomicroscope. Analysis of variance (ANOVA) and Tukey's post hoc test compared the means and standard deviations (SD) after SBS testing (p = 0.05). The highest score of bond strength was exhibited by group C1 (21.14 ± 1.05 MPa-Etch & rinse + Tetric-N- Bond) whereas group C2 (12.15 ± 0.28 -PDT MBPS + Tetric-N-Bond, No treatment group) demonstrated the lowest SBS. Based on the application of haemostatic agent, bond values among subgroups A1 (18.75 ± 1.05 MPa - Expasyl + Etch & rinse + Tetric-N-bond) and B1 (17.84 ± 0.11 MPa -Viscostat + Etch & rinse + Tetric-N-Bond) was comparable (p>0.05). Based on the conditioning methods, bond scores among groups C1 (21.14 ± 1.05 MPa -Etch & rinse + Tetric-N- Bond) and C3 (19.05 ± 1.28 MPa -Clearfill SE) were comparable (p >0.05). Viscostat and Expasyl result in compromised bond integrity of composite restoration to dentin in etch and rinse and self-etch group compared to no treatment group. However, the pre-application of Viscostat and Expasyl on dentin conditioned with PDT improved bond integrity of composite resin.

Dentin Bond Strength and Microleakage Comparison of Three Different Universal Adhesives

Objectives: The aim of this study is to compare the bond strengths and microleakage values of three different universal adhesive systems applied in self-etch to dentin. Materials and Methods: The study consists of two tests as the bond strength (SBS) test and microleakage test. In the SBS test, the mid-coronal dentin surfaces of forty-five human molars were exposed and randomly assigned into three groups [Single Bond Universal, Optibond XTR, and Tokuyama Universal] and adhesive systems were applied to dentin surfaces. The SBS test was performed after composite build-up. Then, the fracture surfaces were evaluated with a scanning electron microscope (SEM). In the microleakage test, identifical adhesive systems were applied to forty-five human premolars with fasial class V cavities were prepared as in the groups specified in the SBS. After composite resin restoration of cavities, the specimens were thermocycled for 500 cycles and then immersed in basic fuchsine, sectioned, and examined under a stereo-microscope. Data were evaluated using one-way ANOVA, Tukey’s, Chi-square and Mann Whitney U tests. Results: Among the adhesives, the highest bond strength was achieved in Optibond XTR, while Tokuyama Universal showed the lowest (p&amp;lt;0.05). When evaluated for microleakage, no significant difference was reported in occlusal margins. In gingival margins, Optibond XTR showed less leakage compared to Tokuyama Universal (p&amp;lt;0.05). Conclusions: One-step universal adhesive systems did not show bond strength and leakage resistance that was as good as the two-step universal adhesive system.

Effect of silver diamine fluoride pretreatment on microleakage and shear bond strength of resin modified glass ionomer cement to primay dentin (in-vitro study)

Objectives: To evaluate in vitro, the effect of 38% silver diamine fluoride (SDF) pretreatment on the microleakage and shear bond strength of resin-modified glass ionomer cement to primary dentin. Materials and methods: A total of 80 extracted sound primary molars were included in this in-vitro study and randomly assigned into four equal groups (n=20 teeth/group) according to the evaluation test performed. For microleakage test, class V cavities were prepared on the buccal surface of forty teeth and randomly allocated into Group I (experimental)(n=20): Primary dentin pretreated with 38% SDFfor three minutes and Group II (control)(n=20): Primary dentin treated with distilled water for three minutes. Class V cavities were restored with RMGIC, thermocycled, immersed into 1% methylene blue solution for 24h, sectioned longitudinally in a bucco-lingual direction and then examined under stereomicroscope at 40x magnification. Also forty teeth were assigned for SBS test and randomly grouped into Group III (experimental) (n=20): Primary dentin flat surface pretreated with 38% SDF. Group IV (control) (n=20): Primary dentin flat surface pretreated with distilled water. Using a Universal Testing machine SBS were determines. Failure mode was evaluated using stereomicroscope. Data were collected and subjected to statistical analysis. Results: There was no statistically significant difference in microleakage between experimental and the control group (P=0.21). However, the experimental group had significantly higher SBS than the control group. (P=0.0001) Conclusion: Primary dentin pretreatment with 38% SDF does not influence the marginal seal of RMGIC to primary dentin. However, it raises the shear bond strength between them.

Adhesive strength of bioactive resin for endodontic tooth build up to dentin treated with conventional and contemporary treatments.

The aim of present ex-vivo study was to assess and evaluate the influence of alternative dentinal conditioning methods- Er,Cr:YSGG (ECL) and Photodynamic therapy (PDT) in comparison to traditional etching regimes- Self Etch Resin (SER) and total etch and rinse (TER) on the bond values of Bioactive restorative material (BA) and Multicore (MC) bulk filled resin composite restorations. Eighty caries free mandibular molars were disinfected and embedded in acrylic resin up to Cemento enamel junction (CEJ). Buccal surfaces of all samples were grounded to depth of 2 mm. Specimens were divided into eight groups (n = 20) based on surface treatment received. Samples in group 1 and 2 conditioned with ECYL, group 3 and 4 pre-treated with methylene blue photosensitizer (MBP), group 5 and 6 surfaces conditioned with TER and samples in group 7 and 8 conditioned with SER. Dentin bonding agent was applied and samples of group 1, 3, 5 and 7 were bonded with BA and 2,4,6,8 bonded to MC. Samples were placed in universal testing machine for SBS testing. Data was assessed using analysis of variance (ANOVA) and Tukey multiple comparisons test. Specimens in group 6 treated with TER and bonded with MC demonstrated maximum SBS (19.61 ± 0.587 MPa). Whereas, group 3 dentin conditioned to MBP and bonded to BA displayed lowest bond values (12.01 ± 0.892 MPa). Samples in group 3 and group 4 dentin treated with MBP bonded to MC (13.68 ± 0.221 MPa) and BA (12.01 ± 0.892 MPa) displayed comparable bond integrity (p > 0.05) CONCLUSION: Dentin pre-treated with TER still remains the gold standard. ECYL as an alternative approach to condition dentin has shown potential and can be recommended in clinical settings. MC as bulk fill composite is recommended over BA irrespective of dentine conditioning technique. MBP as dentin conditioner needs further investigation.

Effects of aging on shear bond strength to dentin and mechanical properties of restorative glass ionomer cements

ObjectivesTo evaluate the shear bond strength to dentin (SBS), flexural strength (FS), and diametral tensile strength (DTS) of four restorative glass ionomer cements after aging in artificial saliva. Materials and methodsFor SBS testing, sound molars were ground to flat occlusal dentin and fixed with acrylic resin. Teeth were randomly divided into four groups along with the following materials: Ketac Nano, Ketac Molar, Fuji II LC and Equia. Glass ionomer cylinders were bonded to each dentin surface. For testing the mechanical properties, FS bars (25 mm × 2 mm x 2 mm) and DTS discs (4 mm × 2 mm) were fabricated. All specimens were stored in artificial saliva (37 °C) and tested after 24 h and 6 months. Data was analyzed with two-way ANOVA and post-hoc Tukey's tests (α = 5%). ResultsThe SBS results were statistically similar among the four glass ionomer cements (p > 0.05). No significant differences in SBS after 24-h and 6-month storage were found, except for in the Ketac Nano group, where a significant decrease in SBS was found after aging (p < 0.05). All materials had a significant increase in FS after aging. The DTS values did not change significantly after aging, with the exception of the Fuji II LC group. Overall, the Fuji II LC group showed significantly higher DTS and FS compared to the other materials. ConclusionsAging for 6 months did not affect the SBS of restorative glass ionomer cements, except in the case of Ketac Nano. All glass ionomer cements showed increased FS over time. The DTS remained unchanged – except for the Fuji II LC, which experienced increased DTS.

Comparison of shear bond strength as affected by ozonated water, fluoride varnish &amp; casein phosphopeptide – Amorphous calcium phosphate

A translatory research to validate antimicrobial and re-mineralization agents to reduce white spot lesions which would not unfavorably affect shear bond strength and focus on ozonated water being a valid and relatively inexpensive method for orthodontic patients to follow as a home follow up care.Tooth surfaces of 60 Extracted Human Premolar Teeth were cleaned and divided into four groups of 20 each and then treated with fluoride varnish, CPP-ACP, Ozonated water and distilled water before bonding brackets and later subjected to SBS testing. SBS of teeth treated with Ozone water and CPP-ACP were close to ideal SBS. Ozone water is a valid and relatively inexpensive method for orthodontic patients to follow as a home follow up care.

Efficacy of chlorhexidine, Er Cr YSGG laser and photodynamic therapy on the adhesive bond integrity of caries affected dentin. An in-vitro study.

To evaluate the adhesive bond integrity (shear bond strength-SBS) of composite resin bonded to carious dentin using chlorhexidine gluconate (CHX), Er,Cr:YSGG laser (ECYL) and photodynamic therapy (PDT). Thirty carious and ten non-carious mandibular teeth were collected through non-traumatic extraction. All samples were embedded in polyvinyl cross-sections to the cemento-enamel junction. The preparation of caries-affected dentin was performed by grinding the specimens using silicon carbide discs. All specimens were randomly allocated in to four groups (n = 10). Group 1, non-affected dentin with no disinfection; Group 2, caries affected dentin treated with 2% CHX; Group 3, affected dentin disinfected with PDT [100 mg/L methylene blue solution (MBS) and Diode laser]; Group 4, affected dentin treated with ECYL. Self-etch adhesive was smeared on all specimens for 10 s and photopolymerized for 10 s. All specimens were placed in an incubator with humid environment for 24 h at 37 °C followed by positioning in universal testing machine for SBS testing. Failure mode examination of debonded samples was performed by a stereomicroscope. Analysis of variance (ANOVA) was used for inter group comparison through mean and standard deviation of each group. For multiple group comparison Tukey HSD was employed. Level of significance was established at p < 0.05. The highest SBS value was observed in group 1 (24.98 ± 1.59 MPa). Whereas, the lowest bond strength was displayed by group 3 (14.22 ± 1.40 MPa) specimens. Lased dentin in group 4 (15.89 ± 3.22 MPa) exhibited SBS values comparable to group 3 (14.22 ± 1.40 MPa). Group 2 (CHX-18.25 ± 1.29 MPa) exhibited statistically significant difference compared to all experimental groups (p < 0.05). Adhesive bond strength of disinfected carious dentin was higher with CHX treatment as compared to Photodynamic therapy and Er,Cr: YSGG laser treatment. Carious dentin showed lower bond strength to composite resin as compared to non-carious dentin.

Strength and bondability of a dental Y-TZP after silica sol-gel infiltrations

This study aimed to evaluate the effects of silica-dipping infiltration in zirconia, using sol-gel method, on flexural strength, short-term and long term bond strengths to resin cement, microstructure and surface characteristics. 330 specimens were made of zirconia (InCeram YZ, Vita Zahnfabrik) and divided into 6 groups: no infiltration (control); slow and fast (ammonium carbonate as catalyst): infiltrations with silicic acid obtained from sodium metasilicate, and infiltration with silicic acid obtained from TEOS. Fast infiltration was further performed second and third times. The disks were characterized using XRD, FT-IR and SEM and then submitted to a biaxial flexural test (BFT). To measure the shear bond strength (SBS test), zirconia specimens were superficially treated and bonded with resin cement. Specimens were tested either before and after thermal aging. BFT and SBS data in MPa were analyzed with one- or two-way ANOVA and Tukey (95%) tests. Weibull analysis was used to determine the structural homogeneity (95% CI). The infiltrated groups presented ZrSiO4 peaks, showing that the infiltration was effective. SEM images showed a homogeneous silica layer on the surface of all infiltrated groups, except those TEOS-infiltrated. The 2-immersion group presented improved structural homogeneity (higher Weibull modulus), including all the infiltrations with metassilicate, and 3-immersions (1104.4 MPa) and Control (1082.1 MPa) groups provided the highest strength. In groups without ageing, the slow infiltration (11.39 MPa) and the fast infiltration after 2 immersions (9.10 MPa) had higher bond strength values. After ageing, a significant decrease in bond strength was observed; the 3-immersion fast infiltration showed higher bond strength (5.77 MPa). Silica infiltration by the sol-gel method can be effectively applied in as little as 40 min with use of a catalyst. This method produces a zirconia with increased reliability that is suitable for adhesive bonding. The protocol presenting the best combination of flexural and bond strength was the 3 immersion-bath in silica sol.