Comparative Evaluation of Microtensile Bond Strength in Three Different Dentin Luting Agents: An In vitro Study.

Aim: Long-term clinical success on indirect restorations is largely determined by bonding efficiency of the luting agent, with adhesion to dentin being the main challenge. Therefore, aim of this study was to assess the microtensile bond strength when using flowable resin composite, preheated resin composite and dual self-adhesive resin cement as dentin luting agents. Materials and Methods: Occlusal thirds of molar teeth were cut and randomly divided into 3 groups to be cemented: RelyX™U200, Filtek™ Z250 XT- preheated to 70° and Filtek Flow™ Z350XT. They were then thermocycled 5000 times between 5+/-2°C and 55+/-2°C. Subsequently, 10 microbars per group were prepared. The 30 samples were placed in saline solution for 24 hours at room temperature prior to microtensile test. This was performed with a digital universal testing machine at a crosshead speed of 0.5 mm/min. The bond strength values obtained were analyzed in Megapascals (MPa). Measures of central tendency such mean and measures of dispersion such standard deviation were used. In addition, the Kruskall Wallis non-parametric test with Bonferroni post hoc test was applied, considering a significance value of 5% (P < 0.05), with type I error. Results: The dentin microtensile bond strengths of preheated resin composite, flowable resin composite and dual self-adhesive cement were 6.08 ± 0.66 Mpa, 5.25 ± 2.60Mpa and 2.82 ± 1.26Mpa, respectively. In addition, the preheated resin composite exhibited significantly higher microtensile bond strength compared to the dual self-adhesive cement (P < 0.001). While the flowable resin composite showed no significant difference with the dual self-adhesive cement (P = 0.054) and the preheated resin composite (P = 0.329). Conclusions: The microtensile bond strength in dentin was significantly higher when using a preheated resin composite at 70°C as a luting agent compared to dual self-adhesive cement. However, the preheated resin composite showed similar microtensile bond strength compared to the flowable resin composite.

Antibacterial Properties and Shear Bond Strength of Titanium Dioxide Nanoparticles Incorporated into an Orthodontic Adhesive: A Systematic Review.

Objective: The present review was conducted to test whether the addition of titanium dioxide (TiO2) nanoparticles (NPs) within orthodontic bracket adhesives would alter their properties and assess their antimicrobial activity against cariogenic microorganisms in addition to noteworthy mechanical properties. Materials and methods: Using predetermined inclusion criteria, an electronic search was conducted using Dissertations and Thesis Global, the Web of Science, Cochrane, Scopus, and Medline/PubMed. Specific terms were utilized while searching the database. Results: Only seven of the 10 included studies assessed shear bond strength (SBS). The mean SBS among the control group varied from 9.43 ± 3.03 MPa to 34.4 ± 6.7 MPa in the included studies, while in the experimental group, it varied from 6.33 ± 1.51 MPa to 25.05 ± 0.5 MPa. Antibacterial activity was assessed in five of the 10 included studies using TiO2 NPs, which could easily diffuse through bacterial media to form the growth inhibition zone. Conclusion: Antibacterial NPs added to orthodontic adhesives at a concentration of 1-5 wt% inhibit bacterial growth and have no effect on bond strength. How to cite this article: D Tivanani MVD, Mulakala V, Keerthi VS. Antibacterial Properties and Shear Bond Strength of Titanium Dioxide Nanoparticles Incorporated into an Orthodontic Adhesive: A Systematic Review. Int J Clin Pediatr Dent 2024;17(1):102-108.

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 × 2 mm) 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) (15.61 MPa) while control + TUB showed the lowest SBS (7.63 MPa). 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.

Micro-tensile bond strength of two pit and fissure sealants to intact enamel.

Background: Sealing dental pits and fissures with resin-based sealants effectively prevents occlusal dental caries. The effectiveness of resin-based pit and fissure sealants relies on maintaining a strong bond between the sealant and the enamel. Objective: This in-vitro study compared the micro-tensile bond strength (µTBS) of a conventional resin-based sealant (Clinpro™) and a hydrophilic resin-based sealant (Embrace™ WetBond™) when applied to intact, aprismatic human enamel. Methods: Forty extracted permanent premolar and molar teeth were divided into two groups and paired by tightly approximating two buccal surfaces to create an artificial enamel groove (fissure). Fissure sealants (Clinpro™ and Embrace™ WetBond™) were applied to the artificial enamel 'grooves' in each group. The specimens were then cut into beams with a cross-sectional area of 1 mm2 and tested for the micro-tensile bond strength (µTBS). Fractured surfaces of samples were examined under a conventional microscope to identify the failure modes. Two specimens from each group were prepared and observed under a scanning electron microscope (SEM). Mann-Whitney U and Fischer-Freeman-Holton exact tests were used to test the statistical differences between the fissure sealants. Results: The µTBS mean ± SD for Clinpro™ was 16.43 ± 7.08, and 10.57 ± 6.64 for Embrace™ WetBond™. There was a statistically significant difference in µTBS between Embrace™ WetBond™ and Clinpro™ (p < 0.001). There was no association between fissure sealant and failure modes (p = 0.922). Conclusion: Clinpro™ showed higher µTBS to enamel than Embrace™ WetBond™. Further studies are needed to conclude the clinical effectiveness of these sealants.

Evaluation of the Curing of the Primer on Shear Bond Strength of Orthodontic Brackets: An Original Research.

Background: The aim of this study was to evaluate the effect of separately curing the unfilled resin for increased bond strength of the orthodontic brackets as the literature shows both studies that support and contradict this aspect. Methodology: The sample consisted of 120 specimens randomly grouped into four of 30. The tooth was cleaned of tissue and debris and stored in a distilled water solution until the procedures of bonding. The surface of the enamel was conditioned with pumice, and acrylic blocks were designed for the tooth to be mounted onto them. The buccal surfaces of all the teeth were prepared by etching the enamel with 37% phosphoric acid for a time period of 30 seconds and washed for 20 seconds under running water. Stainless steel brackets (Victory Series™ MBT, 0.022 Slot) were used for all the samples in the study, and the bonding procedure was conducted on the same day for all the groups. The artificial saliva was used for the storage of samples for 24 h after bonding, and shear bond strength testing was conducted using an Instron machine in shear or peel mode at a crosshead speed. Results: The highest mean bond strength calculated was for the conventional technique (17.45 mpa), while it was the lowest for no primer adhesive (11.21 mpa). Group IV had a greater distribution of ARI scores than groups I, II, and III. Conclusion: Group IV achieved the highest bond strength when compared to other groups, with an ARI score of 3. Group III had less bond strength, likely due to incomplete curing of the primer due to insufficient exposure to light. Transbond XT can be used without primer, making bonding, debonding, and cleaning procedures easy and less time-consuming.

Assessment of a Bracket-Bonding System's Shear Bond Strength after it has been Cured using Various Light-Curing Units at Different Time Intervals.

Objectives: To assess a bracket-bonding system's shear bond strength cured with dissimilar light-curing units at different time intervals. Materials and Method: Sixty premolar teeth removed for orthodontic purposes were categorized into four types based on the light-curing unit and exposure times used. The specimens in the halogen group were exposed to light for 15 (Group I) and 30 (Group II) sec, respectively. The specimens were exposed to light for 10 (Group III) and 15 sec in the LED group (Group IV). The amount of adhesive still present on the teeth was measured using a stereomicroscope at a magnification of 10 and was then assessed with the help of adhesive remnant index (ARI). Result: The group with the highest mean SBS was in Group II followed by Group I, Group III, and the group with the lowest mean SBS. The ARI was unaffected by the light-curing technique, with score 2 predominating. Conclusion: In all groups, polymerization using halogen and LED led to SBS values that were clinically suitable for orthodontic procedures.

Evaluation of Bond Strength and Adhesive Remnant Index of Different Lingual Retainers in Human Incisor Teeth.

Objective: This study aimed to evaluate and compare the bond strengths of four different lingual retainers and assess the adhesive remnant index (ARI) to determine their effectiveness in orthodontic retention. Methodology: Eighty human incisor teeth were divided into four groups, with each group bonded using a different retainer: Group 1 (E-Glass retainer), Group 2 (0.017" Co-axial stainless steel wire), Group 3 (Splint C.T. fiber mesh), and Group 4 (0.010" stainless steel ligature wire). Bond strength was measured using a universal testing machine, and ARI scores were recorded to assess bond failure types. Results: Group 1 (E-Glass retainer) demonstrated the highest bond strength, followed by Group 3 (Splint C.T. fiber mesh), Group 2 (Co-axial stainless steel wire), and Group 4 (stainless steel ligature wire). Cohesive bond failures were observed in most groups, except for the co-axial stainless steel wire group, which exhibited adhesive failures. Conclusion: E-Glass fiber-reinforced retainers showed the highest bond strength, making them a promising alternative to conventional stainless steel wires for orthodontic retention, especially in patients with esthetic concerns or nickel hypersensitivity. Stainless steel retainer groups exhibited lower bond strengths, and cohesive bond failures were prevalent. Further research is needed to validate these findings in clinical settings and evaluate the long-term effectiveness of different lingual retainers.

The Use of Lasers in Enhancing the Bond Strength of Orthodontic Brackets.

Background: The use of lasers in orthodontics has garnered interest for its potential to enhance the bond strength between orthodontic brackets and tooth surfaces, a crucial factor for successful orthodontic treatment. This study aims to investigate the effect of laser irradiation on the bond strength of orthodontic brackets in a sample of 30 patients. Materials and Methods: Thirty patients undergoing orthodontic treatment were divided into two groups. In Group A, brackets were bonded using conventional methods, while in Group B, brackets were bonded after laser irradiation. A diode laser operating at 810 nm was used, with an energy setting of 2.5 W for 20 s. After bonding, a universal testing machine measured the bond strength in megapascals (MPa). The adhesive remnant index (ARI) was also recorded to determine the mode of bond failure. Statistical analyses were conducted to compare the results between the groups. Results: The mean bond strength in Group B (laser irradiation) was significantly higher (P < 0.05) than in Group A (conventional bonding). Group B exhibited a mean bond strength of 9.72 MPa, whereas Group A showed a mean bond strength of 7.41 MPa. The ARI scores indicated that Group B had more adhesive remaining on the tooth surface, suggesting a stronger bond. Conclusion: Laser irradiation prior to orthodontic bracket bonding resulted in significantly enhanced bond strength compared to conventional bonding methods. The increased bond strength and greater adhesive remnant on the tooth surface indicate that laser irradiation improves the adhesion between brackets and tooth enamel. Integrating lasers into orthodontic procedures has the potential to elevate treatment outcomes by ensuring durable bracket adhesion.

Assessment of Efficacy of Various Bracket Base Retention Qualities on Shear Bond Strength.

Introduction: Numerous manufacturers have improved bracket retention systems as a result of the frequent bond failure that occurs during orthodontic treatment. One of the elements affecting the adhesive's bond strength is the bracket retention mechanism. Objectives: This study's objective was to assess how various bracket base retention characters affected shear bond strength. Materials and Methods: Four distinct base features for brackets were evaluated. The basic design was examined using a scanning electron microscope. On the Universal testing equipment, brackets were glued to human teeth and then released. Results: The findings indicate that the polymer-coated base's overall mean SBS, which had a mean value of 21.64 ± 4.14 MPa, was considerably greater than that of the other brackets (P 0.05). The foil meshpad, photochemically etched base, and laser-structured base had mean SBS values of 15.12 ± 5.75 MPa, 16.86 ± 3.76 MPa, and 19.32 ± 4.23MPa, respectively. Conclusions: Following laser-structured base and photochemically etched base brackets in terms of shear bond strength were polymer-coated base brackets. The shear bond strength was the lowest in the plain foil mesh pads.

Comparative Evaluation of the Push-Out Bond Strength of Glass Ionomer Cement, Mineral Trioxide Aggregate, Biodentine, and Endosequence Root Repair Material in Repair of Furcation Perforations: An In Vitro Study.

Introduction: An in vitro comparative analysis was performed to calculate the push-out bond strength of commercially existing root repairing cements like glass ionomer cement (GIC), biodentine, mineral trioxide aggregate (MTA), and endosequence root repair material (RRM) employed in furcation perforation, with or without blood contamination present. Materials and Methods: Eighty molars were selected and subjected to furcal perforations. They were categorized based on the cement used for repair (GIC, MTA, biodentine, and endosequence RRM); furthermore, they were sub-divided into two sub-groups, that is, blood contaminated and non-contaminated. For 24 hours, all the samples were kept in an incubator till the materials were fully set. Then these samples were examined for push-out bond strength measurement. Results: The 24-hour push-out bond strength of was the highest in biodentine and the lowest in glass ionomer cement. The push-out bond strength of endosequence RRM, MTA, and GIC was influenced by blood contamination. Conclusion: The push-out bond strength of biodentine was the highest as compared to endosequence RRM, MTA angelus, and GIC. The push-out bond strength of endosequence RRM and MTA angelus after 24 hours with or without blood contamination showed insignificant differences. Group 1A (GIC contaminated with blood) displayed the least push-out bond strength among other groups.

Effect of Casein Phosphopeptide-Amorphous Calcium Phosphate, Proanthocyanidin, Carbon Dioxide Laser Remineralization on the Bond Integrity of Composite Restoration Bonded to Caries Affected Dentin.

Objective: Assessment of different remineralizing pretreatment casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), proanthocyanidin (PA), carbon dioxide laser (CO2), eggshell solution (ES) on the shear bond strength (SBS) of resin composite bonded to remineralized carious-affected dentin (CAD). Materials and methods: Eighty human molars were collected with occlusal caries that extended about halfway into the dentin. Using a water-cooled, low-speed cutting saw, a flat, mid-coronal dentin surface was exposed. CAD was differentiated from healthy dentin. Based on the remineralizing agent used on the CAD surface, the teeth were arbitrarily allocated into five groups (n = 10). Group 1: no remineralizing agent, Group 2: CPP-ACP, Group 3: 6.5% PA solution, Group 4: CO2 laser, and Group 5: ES solution. All samples were bonded to composite and light cured and thermocycled. SBS and failure mode analysis were performed using universal testing and stereomicroscope 40 × . Using SPSS, SBS, and failure mode data were analyzed using analysis of variance and Tukey's honesty significant difference (HSD) test Results: Group 3 (6.5% PA solution; 15.59 ± 1.44 MPa) samples established the maximum bond integrity. Nevertheless, Group 1 (No remineralizing agent; 11.19 ± 1.21 MPa) exhibited the minimum outcome of bond strength. Intergroup comparison analysis showed that Group 1 (No remineralizing agent), Group 2 (CPP-ACP), and Group 4 (CO2 laser) established comparable values of bond strength (p > 0.05). Likewise, Group 3 (6.5% PA solution) and Group 5 (EA solution) also revealed equivalent bond integrity (p > 0.05). Conclusions: PA and ES are considered potential remineralizing agents used for caries-affected dentin surfaces in improving bond integrity to composite resin. However, further studies are advocated to extrapolate the findings of this study.

Long-Term Bonding Efficacy of CAD/CAM Hybrid Restorative Materials and Universal Adhesives.

OBJECTIVES: In-office and lab milled prostheses are the staple for indirect restorations. It is therefore critical to determine their long-term bonding durability. METHODS: CAD/ CAM blocks of two classes of restorative materials: 1) a nano-ceramic reinforced polymer matrix (NCPM) and, 2) a polymer-infiltrated ceramic network (PICN) were bonded using four different universal adhesives (UA) and silane systems. A lithium disilicate glassceramic (LDS) was used as a reference. The blocks were bisected and bonded with different UA/resin-cement pairs. Bonded blocks were then cut into 1.0x1.0x12.0 mm bar specimens for microtensile bond testing. Half the bars were subjected to bond strength testing immediately and the other half after aging by 50,000 thermal cycles between 5°C and 55°C. ANOVA and post-hoc tests were used to compare mean bond strength among groups. RESULTS: NCPM presented consistently high bond strength regardless of bonding techniques, while the bond strength of PICN and LDS were lower when bonded with UA relative to traditional silanes. The more hydrophilic UA produced higher bond strengths. DISCUSSION: Glass-ceramics exhibited lower bond strength with UA than the conventional etch-rinse-silane techniques. However, UAs preserved bonding interface in the long-term. SIGNIFICANCE: NCPM displayed superior bond strength relative to PICN and LDS regardless of the type of adhesives and bonding techniques.

Influence of resin-coating techniques on the marginal adaptation and the bond strengths of CAD/CAM-fabricated hybrid ceramic inlays.

This study aimed to evaluate the effects of different resin-coating technique strategies and dual-cure resin luting materials on proximal marginal adaptation and the microtensile bond strengths (µTBSs) of CAD/CAM hybrid ceramic inlays. Extracted human molars were classified into four groups, depending on the coating technique: No coating (None), single coating (1-coating), double coating (2-coating), and flowable resin-coating (Combination). The inlays were bonded with one of the three materials: Panavia V5 (V5), Rely X Ultimate (RXU), and Calibra Ceram (CC). The differences with regard to adaptation were not significant. In the case of µTBS data for V5, no significant differences were observed, whereas for RXU, µTBS values for Combination statistically exceeded those for None and 1-coating. For CC, µTBS values for Combination statistically exceeded those for None, 1-coating, and 2-coating. The coating techniques did not influence the adaptation but influenced the bond strength, and Combination performed the best.

Shear bond strength of ultraviolet-polymerized resin to 3D-printed denture materials: Effects of post-polymerization, surface treatments, and thermocycling.

PURPOSE: The purpose of this study is to compare the shear bond strength of ultraviolet (UV)-polymerized resin to 3D-printed denture materials, both with and without post-polymerization. Moreover, the effects of surface treatment and thermocycling on shear bond strength after post-polymerization were investigated. METHODS: Cylindrical 3D-printed denture bases and teeth specimens were prepared. The specimens are subjected to two tests. For Test 1, the specimens were bonded without any surface treatment or thermal stress for comparison with and without post-polymerization. In Test 2, specimens underwent five surface treatments: untreated (CON), ethyl acetate (EA), airborne particle abrasion (APA) with 50 µm (50-APA) and 110 µm alumina (110-APA), and tribochemical silica coating (TSC). A UV-polymerized resin was used for bonding. Half of the Test 2 specimens were thermocycled for 10,000 cycles. Shear bond strength was measured and analyzed using Kruskal-Wallis and Steel-Dwass tests (n = 8). RESULTS: In Test 1, post-polymerization significantly reduced shear bond strength of both 3D-printed denture materials (P < 0.05). No notable difference was observed between the denture teeth and the bases (P > 0.05). In Test 2, before thermocycling, the CON and EA groups exhibited low bond strengths, while the 50-APA, 110-APA, and TSC groups exhibited higher bond strengths. Thermocycling did not reduce bond strength in the latter groups, but significantly reduced bond strength in the EA group (P < 0.001). CONCLUSIONS: Post-polymerization can significantly reduce the shear bond strength of 3D-printed denture materials. Surface treatments, particularly APA and TSC, maintained bond strength even after thermocycling.

Canal disinfection using Nd: YAG Laser, synchronized microbubble-photodynamic activation, and carbon quantum dots on microhardness, smear layer removal, and extrusion bond strength of zirconia post to canal dentin. An invitro scanning electron microscopic analysis.

Evaluation of the impact of the latest root canal disinfectant, that is carbon quantum dots (CQDs), synchronized microbubble-photodynamic activation (SYMPA), and Nd: YAG laser along with ethylenediaminetetraacetic acid (EDTA) as a final irrigant on the Marten hardness (MH), smear layer (SL) removal, and extrusion bond strength (EBS) of zirconia post to the canal dentin. Eighty intact single-rooted premolars were obtained and disinfected using 0.5% chloramine-T solution. Root canal preparation was performed using ProTaper files followed by obturation. The post space was prepared for prefabricated zirconia post and all the teeth were randomly divided into four groups based on the disinfection used (n = 20 each) Group 1: 5.25% NaOCl + 17% EDTA (Control), Group 2: Nd: YAG laser + 17% EDTA, Group 3: SYMPA + 17% EDTA, and Group 4: CQDs + 17% EDTA. MH, SL removal, and EBS of zirconia post-bonded to root dentin were performed using a microhardness tester, scanning electron microscope (SEM), and universal testing machine, respectively. Both intragroup and intergroup comparisons were performed using one-way analysis of variance (ANOVA) and posthoc-Tukey test for significant difference (p < .05). Group 2 samples (Nd: YAG laser + 17% EDTA) (0.24 ± 0.06 GPa) exhibited highest values of MH. Samples in group 3 (SYMPA + 17% EDTA) treated teeth unveiled the lowest MH scores (0.13 ± 0.02 GPa). Moreover, the coronal third of Group 3 specimens (SYMPA and 17% EDTA) (1.54 ± 0.31) eliminated SL from the canal with the greatest efficacy as well as presented the highest EBS (10.13 ± 0.69 MPa). However, the apical third of Group 1 samples (5.25% NaOCl + 17% EDTA) (2.95 ± 0.33) exhibited the least efficient elimination of SL from the radicular dentin as well as the lowest bond strength (5.11 ± 0.19 MPa) of zirconia post to the dentin. The SYMPA technique with 17% EDTA proved highly effective in removing the SL from canal dentin and enhancing the EBS of zirconia posts. The least preferable method for SL removal and MH improvement was found to be 5.25% NaOCl + 17% EDTA. CQDs and Nd: YAG laser demonstrated satisfactory smear layer removal properties from the canal, along with achieving appropriate bond strength of zirconia posts. RESEARCH HIGHLIGHTS: Nd: YAG laser and 17% EDTA as canal disinfectant exhibited the highest values of MH. Specimens irrigated with SYMPA and 17% EDTA eliminated SL from the canal with the greatest efficacy. The coronal third of Group 3 (SYMPA + 17% EDTA) samples unveiled the highest zirconia post-bond integrity score to the canal dentin. Cohesive failure was a dominant failure type among different experimental groups.

Formulation of arginine-loaded mesoporous silica nanoparticles (Arg@MSNs) modified orthodontic adhesive.

OBJECTIVES: The objective of this study was to synthesize arginine loaded mesoporous silica nanoparticles (Arg@MSNs), develop a novel orthodontic adhesive using Arg@MSNs as modifiers, and investigate the adhesive performance, antibacterial activity, and biocompatibility. METHODS: Arg@MSNs were synthesized by immobilizing arginine into MSNs and characterized using transmission electron microscope (TEM), dynamic light scattering (DLS), and Fourier Transform Infrared Spectrometer (FT-IR). Arg@MSNs were incorporated into Transbond XT adhesive with different mass fraction to form functional adhesives. The degree of conversion (DC), arginine release behavior, adhesive performance, antibacterial activity against Streptococcus mutans biofilm, and cytotoxicity were comprehensively evaluated. RESULTS: TEM, DLS, and FT-IR characterizations confirmed the successful preparation of Arg@MSNs. The incorporation of Arg@MSNs did not significantly affect DC and exhibited clinically acceptable bonding strength. Compared to the commercial control, the Arg@MSNs modified adhesives greatly suppressed the metabolic activity and polysaccharide production while increased the biofilm pH values. The cell counting kit (CCK)-8 test indicated no cytotoxicity. CONCLUSIONS: The novel orthodontic adhesive containing Arg@MSNs exhibited significantly enhanced antibacterial activities and inhibitory effects on acid production compared to the commercial adhesive without compromising their bonding strength or biocompatibility. CLINICAL SIGNIFICANCE: The novel orthodontic adhesive containing Arg@MSNs exhibits potential clinical benefits in preventing demineralization of enamel surfaces around or beneath orthodontic brackets due to its enhanced antibacterial activities and acid-producing inhibitory effects.

Can a Self-etching Primer be Effective in Bonding Aligner Attachments to Different Types of Ceramics?

Objective: This in vitro study aimed to evaluate the effectiveness of pretreatment with a self-etching primer for bonding aligner attachments to lithium disilicate (LD) and monolithic zirconia (MZ) ceramics. Methods: Forty ceramics, including LD (n=20) and MZ (n=20), were divided into four study groups according to the surface pretreatments: LD specimens pretreated with universal primer (Monobond Plus, MP) after hydrofluoric acid etching (Group 1); MZ ceramics pretreated with MP after sandblasting (Group 2); LD ceramics pretreated with self-etching ceramic primer (Monobond etch & prime, MEP) (Group 3); and MZ ceramics pretreated with MEP after sandblasting (Group 4). The aligner composite (GC Aligner Connect) and universal adhesive (GPremio Bond) were used to prepare the resin attachments. The bond strength was evaluated by micro-shear bond strength (SBS) testing (0.1 mm/min) after thermocycling, and the remnant adhesive was scored according to the resin attachment remnant index (RARI). The SBS data were analyzed using ANOVA and Tukey tests, and the RARI scores were analyzed using the chi-square test. Results: Group 1 had the lowest SBS, and group 2 had the highest SBS. There were significant differences between the groups in terms of bond strength (p<0.05). The RARI scores showed no significant differences, regardless of the pretreatment and ceramic type. Conclusion: The use of a self-etching primer increased the bond strength of resin attachments on LD ceramics. For zirconia ceramics, both ceramic primers are recommended for aligner attachment bonding.

Filling Material Bond Strength to Dentin Is Positively Influenced by the Agitation of Endodontic Final Irrigating Solutions.

Introduction: The final step of irrigation has been considered to of increase the bonding strength of filling material to dentin. This study investigated the impact of three final-step irrigation methods on the endodontic sealer bond strength to dentin by using a micro push-out test. Materials and Methods: Palatal roots of human maxillary molars were cleaned and shaped and randomly divided in six groups (n=15) according to the final-step irrigation method and the type of root canal sealer used. The solutions used for the final-step irrigation were 17% ethylenediaminetetraacetic acid and 2.5% sodium hypochlorite, which underwent three methods: 1) syringe-needle irrigation/conventional, 2) passive ultrasonic irrigation, and 3) XP-endo Finisher agitation. The root canal sealers used were: EndoSequence BC Sealer, and AH-Plus sealer. Roots were obturated with the single cone technique and then, cross-sectioned in 2-mm-thick slices (3 slices from each root). Push-out test was performed on the sliced specimens (cervical, middle, and apical thirds) with a universal testing machine. Bond strength values were recorded in megapascal (MPa). Subsequently, each specimen was longitudinally split to verify the type of failure. Data analysis was performed using Johnson transformation, three-way analysis of variance, Tukey's post-hoc tests, and the partial Eta squared test. Results: There were significant differences in bond strength between the sealers [AH: 4.46±2.24 and BC: 3.47±2.19 MPa (P<0.001)]; between final-step irrigation methods [passive ultrasonic irrigation: 4.52±2.25, XP-endo Finisher: 3.93±3.93 and syringe-needle irrigation/conventional: 3.37±2.51 MPa (P<0.001)], and between the root canal thirds represented by the sliced specimens [cervical: 5.45±2.39, middle: 4.14±1.99 and apical: 2.30±1.30 MPa (P<0.001)]. The interaction between the variables had no significance (P>0.05). Conclusion: Agitation of the final irrigating solution may improve the bonding of the sealer to canal walls. AH-Plus sealer had the highest bond strength. The bond strength reduced significantly towards the apical third.

Aluminum zirconate nanoparticles in etch and rinse adhesive to caries affected dentine: An in-vitro scanning electron microscopy, elemental distribution, antibacterial, degree of conversion and micro-tensile bond strength assessment.

To incorporate different concentrations of Al2O9Zr3 (1%, 5%, and 10%) nanoparticles (NP) into the ER adhesive and subsequently assess the impact of this addition on the degree of conversion, µTBS, and antimicrobial efficacy. The current research involved a wide-ranging examination that merged various investigative techniques, including the application of scanning electron microscopy (SEM) for surface characterization of NP coupled with energy-dispersive x-ray spectroscopy (EDX), Fourier-transform infrared (FTIR) spectroscopy, µTBS testing, and microbial analysis. Teeth were divided into four groups based on the application of modified and unmodified three-step ER adhesive primer. Group 1 (0% Al2O9Zr3 NPs) Control, Group 2 (1% Al2O9Zr3 NPs), Group 3 (5% Al2O9Zr3 NPs), and Group 4 (10% Al2O9Zr3 NPs). EDX analysis of Al2O9Zr3 NPs was performed showing elemental distribution in synthesized NPs. Zirconium (Zr), Aluminum (Al), and Oxides (O2). After primer application, an assessment of the survival rate of Streptococcus mutans was completed. The FTIR spectra were analyzed to observe the characteristic peaks indicating the conversion of double bonds, both before and after the curing process, for the adhesive Etch and rinse containing 1,5,10 wt% Al2O9Zr3 NPs. µTBS and failure mode assessment were performed using a Universal Testing Machine (UTM) and stereomicroscope respectively. The µTBS and S.mutans survival rates comparison among different groups was performed using one-way ANOVA and Tukey post hoc (p = .05). Group 4 (10 wt% Al2O9Zr3 NPs + ER adhesive) specimens exhibited the minimum survival of S.mutans (0.11 ± 0.02 CFU/mL). Nonetheless, Group 1 (0 wt% Al2O9Zr3 NPs + ER adhesive) displayed the maximum surviving S.mutans (0.52 ± 0.08 CFU/mL). Moreover, Group 2 (1 wt% Al2O9Zr3 NPs + ER adhesive) (21.22 ± 0.73 MPa) samples displayed highest µTBS. However, the bond strength was weakest in Group 1 (0 wt% Al2O9Zr3 NPs + ER adhesive) (14.13 ± 0.32 MPa) study samples. The etch-and-rinse adhesive exhibited enhanced antibacterial activity and micro-tensile bond strength (µTBS) when 1% Al2O9Zr3 NPs was incorporated, as opposed to the control group. Nevertheless, the incorporation of Al2O9Zr3 NPs led to a decrease in DC. RESEARCH HIGHLIGHTS: 10 wt% Al2O9Zr3 NPs + ER adhesive specimens exhibited the minimum survival of S.mutans. 1 wt% Al2O9Zr3 NPs + ER adhesive samples displayed the most strong composite/CAD bond. The highest DC was observed in Group 1: 0 wt% Al2O9Zr3 NPs + ER adhesive.

PEEK and Glass Fiber Post Pushout Bond Strength and Vickers hardness of Canal disinfected with Curcumin photosensitizer activated by Microbubble emulsion and Sodium-hypochlorite with EDTA.

AIMS: Impact of different post-space disinfectants (Saline, Sodium hypochlorite (NaOCl) followed by ethylene-diamine-tetra-acetic acid (EDTA) and curcumin activated by microbubble emulsion (MBE) on the Vickers hardness (VH) of root canal dentin and extrusion bond strength (EBS) of Glass fiber post (GFP) and PEEK post. METHODS: Ninety maxillary central incisors having fully formed roots were included. After the specimen's disinfection, root canal treatment was completed. Post space was prepared by removing gutta-percha using gates glidden drills. Teeth were then arbitrarily allocated into three groups based on the methods of disinfection regime used. Group 1: Saline, Group 2: NaOCl+ EDTA and Group 3: Curcumin activated by MBE (n=30). Analysis of VH of radicular dentin was performed using a micro-Vickers tester on ten samples from each group. After post-space disinfection, twenty specimens from each group were further divided into two subgroups (n=10) In group-1A 2A, and 3A, GFP was used. Whereas, prefabricated PEEK posts were used in 1B, 2B, and 3B subgroups. The PBS and failure modes were performed using a universal testing machine and stereomicroscope respectively. Data was analyzed using ANOVA and Tukey post hoc test to identify significant variations among groups concerning the MH and EBS of the different posts used (p=0.05). RESULTS: Group 2 (5.25% NaOCl + 17% EDTA) (0.15 ± 0.02 GPa) treated specimens presented lowest scores of VH. However, Group 1 (Saline) irrigated canals displayed the highest scores of surface hardness (0.25± 0.07 GPa). Additionally, a cervical third of 3A (CP activated by MBE + GFP) (11.22±0.79 MPa) presented the highest scores of bond integrity. Whereas Group 1B (Saline + PEEK post) treated specimens presented the lowest scores of PBS (4.15±0.15 MPa). CONCLUSION: Curcumin activated by microbubble emulsion for disinfection of canal dentin demonstrated favorable VH. Similarly, glass fiber post-cemented in radicular walls disinfected with curcumin activated with MBE showed promising post-bond integrity to the canal dentin.