Push-out Bond Strength Research Articles

Effect of Post Sizes and Citric Acid Treatment on the Bond Strength of Fiber Posts Using Self-Etch Resin Cement in Calcium Silicate–Based Sealer Treated Teeth

Abstract Objectives This study evaluated the effects of different post sizes and citric acid (CA) treatment on the bond strength of fiber posts cemented with self-etch resin cement in teeth obturated with calcium silicate–based sealer. Materials and Methods Seventy mandibular premolars were collected and randomly distributed to either a control group (no sealer) or experimental groups obturated with calcium silicate–based sealer (iRoot SP). The experimental groups were classified by post sizes—1.25 mm (no. 1), 1.375 mm (no. 2), and 1.50 mm (no. 3)—and the irrigants used (distilled water [DW] or CA). Prefabricated fiber posts were fixed using NX3 self-etch resin cement. Push-out bond strength was tested in the coronal and middle sections of the roots. Statistical Analysis The data were analyzed using a one-way analysis of variance (ANOVA), followed by a post hoc Duncan test. Results In the coronal section, post size no. 1 with DW showed significantly lower bond strength compared to the other experimental groups (p < 0.05). In the middle section, the larger post sizes (nos. 2 and 3) with CA treatment resulted in a significant increase in bond strength compared to the control group (p < 0.05). Conclusions iRoot SP negatively affected bond strength in the middle section of the canal. However, using larger post sizes (nos. 2 and 3) with CA treatment improved bond strength in the middle section.

Effects of Mechanized Irrigation Protocols on Endodontic Obturation Using Calcium Silicate-Based Sealer

The aim of this study was to evaluate the effects of mechanized final irrigation protocols (XPE, XP-Endo Finisher; XPC, XP-Clean; and ECL, Easy Clean) compared to PUI (passive ultrasonic irrigation) on the debris incidence and open dentinal tubules, and their effects on the adhesion interface after 48 h and 6 months. One hundred twenty maxillary central incisors were submitted to chemical–mechanical preparation using a rotary instrument and 2.5% sodium hypochlorite. Specimens were distributed in 4 groups (n = 30) in accordance with the mechanized final irrigation protocol: XPE, XPC, ECL, or PUI. Forty specimens (n = 10/group) were submitted to SEM analysis to evaluate the residue incidence and dentin open tubules. The other specimens were obturated using Bio-C Sealer and submitted to push-out bond strength and adhesive failure mode evaluations in the cervical, middle, and apical thirds after 48 h or 6 months (n = 10/group). Only in the apical third, ECL presented the highest residue incidence and fewer open dentinal tubules when compared to the XPE, XPC, and PUI groups (p < 0.05). In the cervical and middle root thirds, no significant differences were observed regardless of the group evaluated (p > 0.05). After 48 h, ECL resulted in the lowest bond strength only in the apical third (p < 0.05), while the XPE, XPC, and PUI groups remained similar in the cervical and middle thirds (p > 0.05). At 6 months, all groups showed lower bond strength values regardless of the root third evaluated, but ECL showed the lowest bond strength in the apical and middle root thirds when compared to the other groups (p < 0.05). The ECL protocol did not provide adequate residue removal on the apical radicular third and negatively affected the longevity of endodontic obturation using a calcium silicate-based sealer.

Impact of strontium added fluorophosphate glass on the physico-chemical properties of mineral trioxide aggregate

Mineral trioxide aggregate (MTA) is widely employed in the field of endodontics, extensively for root canal therapy. Despite being successful, MTA has certain limitations regarding its physico-chemical properties. The present investigation aims to enhance the physicochemical and mechanical behavior of MTA by formulating a cement paste by addition of strontium containing fluorophosphate glass (SrFP). The addition of strontium on to the fluorophosphate glass improves the mechanical strength of the glass network and also accelerates the mineralization process during implantation. In this regard, fluorophosphate glasses with 6 mol% of strontium content were synthesized by standard melt quenching technique and the glasses were ball milled to obtain fine powder. Cement paste was prepared by adding optimized 5 wt% of 6 mol% SrFP glass powder on to 95 wt% of MTA cement. Comparative analysis of conventional MTA with SrFP added MTA were evaluated for various properties such as pH variation, contact angle, radiopacity, compressive strength, push-out bond strength, setting expansion, sealing ability, tooth color change, surface morphology and ALP activity. The obtained results from the investigation exposed that the addition of strontium added fluorophosphate on to MTA impacts the physical properties which includes wettability, sealing ability, push out bond strength and ALP. These findings suggest that SrFP to be a promising additive to MTA with wide scope of applications in dentistry.

The Effect of Silver Nanoparticles on Bond Strength of Calcium Silicate-Based Sealer: An In Vitro Study

The aim of this study was to evaluate the bond strength of the calcium silicate-based sealer (CSS) modified with the silver nanoparticles (AgNPs) using the single-cone technique (SC) and the continuous wave condensation (CWC) technique, measured by a universal testing machine. The AgNPs and the modified sealers were characterized by scanning electron microscopy and transmission electron microscopy. One hundred single-rooted extracted human permanent teeth with a single root canal were cleaned and shaped with a Protaper Next system. The teeth were randomly divided into four groups (n = 25) as follows: Group 1, canals were obturated using the SC technique with TotalFill® BC Sealer. Group 2, canals were obturated using the SC technique with TotalFill® BC Sealer mixed with AgNPs. Group 3, canals were obturated using the CWC technique with TotalFill® HiFlow BC Sealer. Group 4, canals were obturated using the CWC technique with TotalFill® HiFlow BC Sealer mixed with AgNPs. After two weeks, 1 mm-thick dentin slices were cut and exposed to a push-out bond strength test using a universal testing machine. Specimens were examined under a digital microscope to determine the mode of failure. Statistical analysis was performed using ANOVA and Tukey multiple comparison tests (p < 0.05). The nanoparticle characterization revealed a spherical morphology with no obvious aggregations. The results showed that group 4 had the highest dislodgement resistance compared to all groups (p < 0.05). Group 4 was significantly higher in push-out bond strength value than group 1 (p < 0.001) and group 3 (p < 0.003), but not significantly higher than group 2. Cohesive failure was the most prevalent failure mode among all groups. It can be concluded that the incorporation of silver nanoparticles into the calcium silicate-based sealer significantly increased the bond strength. The warm obturation approach demonstrated significantly higher resistance to dislodgment as compared to the single-cone technique.

Fiber post cemented using different adhesive strategies to root canal dentin obturated with calcium silicate-based sealer

BackgroundCalcium silicate-based sealer has favorable properties for root canal filling, including hydroxyapatite formation during the setting process. However, this process can cause difficulty during post space preparation when the sealer is set. Additionally, the remaining sealer could interfere with the bond strength of fiber post to root canal dentin. The different adhesive strategies and fiber post cementation time may affect the bond strength of the fiber post. Thus, the objective of this study was to evaluate the effect of etching modes of Scotchbond™ Universal Plus adhesive and post cementation time on the push-out bond strength of a fiber post cemented in root canals obturated with calcium silicate-based sealer.MethodsFifty-four teeth were randomly allocated to 6 groups (n = 9) based on etching modes: self-etch (SE) or etch-and-rinse (ER); post space preparation and cementation time: immediate (Im) or 7-day delayed (De): Im-Im, Im-De, and De-De. The root canals were obturated with calcium silicate-based sealer and the post space preparation was performed. The fiber post was cemented using RelyX™ Universal resin cement according to each group’s design. For the push-out bond strength test, 1-mm slices of the coronal, middle, and apical regions were tested using a universal testing machine. The failure mode analysis was determined using a stereomicroscope. The data was analyzed with three-way analysis of variance.ResultsNo negative effects of etching modes, post space preparation or cementation time on push-out bond strength were detected (p > 0.05). Additionally, the root canal region also did not significantly affect the bond strength (p > 0.05).ConclusionNo significant differences were observed between the etching modes, post space preparation and cementation time and among root canal regions.Clinical relevanceThe different etching modes of adhesive and post cementation time did not affect the bond strength of fiber post in calcium silicate filled-root canal.

Morphological Analysis and Bond Strength to Root Canal Dentin of Endodontically Treated and Retreated Teeth: An Ex Vivo Study.

To assess the bond strength and the hybrid layer (HL) micro-morphological characteristics at the cement-dentin interface (CD-i) between root canal walls and two adhesive resin cements [self-etch (SERc) and self-adhesive (SARc)] in root-canal-treated (RCT) and naturally aged retreated teeth (RCR-T). Vital (n = 16) and RCT (n = 16) teeth were, respectively, endodontically treated or retreated. Fiber posts were luted either with SERc (Clearfil Universal Bond Quick + DC Core Plus) or SARc (iCEM). Samples were then sectioned into 1 mm thick slices perpendicular to the fiber post and submitted to push-out bond strength test. Vital (n = 4) and RCT (n = 4) first maxillary molars were also selected and prepared to evaluate CD-i morphology through confocal laser scanning microscopy (CLSM). Three-way analysis of variance (ANOVA) and Tukey post-hoc tests were assessed to statistically analyze the obtained data (p 0.05). Bond strength was significantly jeopardized in retreated teeth and in the root apical half, while the cements had no significant influence. Most failures occurred between dentin and resin cement. HL thickness was also hindered in retreated teeth. iCEM produced a thinner HL compared to SERc. Resin tag formation was significantly hampered in the root apical half. SARc performed as well as SERc on aged RCT radicular dentin. Clinicians can rely on simplified one-step luting systems when adhesion is required in unfavorable substrates such as the root canal post space of aged RCT teeth.

Comparative evaluation of the strength of adhesion by push-out bond strength tests on endodontic posts cemented with different resinous types of luting cements: An in vitro study

INTRODUCTION. Endodontic posts play a vital role in strengthening debilitated teeth. They are luted into the radicular space using dental cements that are generally resinous. Given that the forces faced by human teeth are loading in nature and the stresses are accumulative, the bond strength of the interfaces at both the radicular dentin and luting agent and the endodontic post and the luting agent needs to be evaluated. Micro pushout bond strength (POBS) testing is done to determine these strengths. This experimental, in vitro study evaluated the adhesion strength of endodontic posts cemented with different resin-based luting agents using micro-POBS.MATERIALS AND METHODS. A total of 30 human lower incisors were selected and divided into three groups (n=10), based on the type of adhesive resin cement used for luting. Prefabricated endodontic fiber posts were inserted into the root canals of each tooth, and different resin types of cement – Estecem II, Multilink Automix, and Relyx Ultimate. were used to cement the fiber posts. The micro-POBS test measured the bond strength of the cemented pins to the root canal dentin.RESULTS. The results showed that the mean POBS of Group B was higher than that of Group A and Group C. The difference between the mean POBSs of Group A and Group C was not statistically significant (p>0.05).CONCLUSION. The resin adhesive cement used can affect the POBS of endodontic posts to root canal dentin. Clinicians should choose the appropriate resin cement for cementing endodontic posts to ensure a strong and durable bond for a good clinical prognosis.

Influence of Natural Dentin Biomodification Agent on Push-Out Bond Strength and Nanoleakage of Self-Adhesive Resin Cement Luting of Glass-Fiber Posts.

To evaluate the plant-derived compound lignin (LIG) as a pretreatment of intraradicular dentin in combination with EDTA on push-out bond strength (PBS) and nanoleakage of the glass fiber posts (GFPs) cemented using adhesive resin cement. Twenty-eight human incisor roots were prepared for GFP cementation and divided based on dentin pretreatment: (1) CONTROL: no pretreatment, (2) EDTA: 17% EDTA for 3 min, (3) EDTA-LIG: 17% EDTA and 2% lignin for 3 min, (4) EDTA-PAC: 17% EDTA and 2% lignin for 3 min. The GFPs were cemented using the self-adhesive resin cement Multilink Speed. The roots (n = 7) were sectioned into 1 mm-thick discs and subjected to PBS testing after 1 week or 6 months. Nanoleakage was analyzed by SEM. Statistical analysis was performed using two-factor ANOVA and Tukey's test (p < 0.05). Higher PBS was identified for the CONTROL group (p < 0.001). After 6 months, the EDTA-LIG maintained the bond strength with a predominance of mixed failures, while the EDTA-PAC, EDTA, and CONTROL groups showed reduction of bond strength, with a predominance of adhesive failures along with severe silver infiltration in the interface. LIG associated with EDTA as a pretreatment for intraradicular dentin shows significant potential for attaining stable bond strength and interfacial integrity of self-adhesive resin cement to intraradicular dentin.

Comparative evaluation of the effect of three different obturation techniques on push-out bond strength of AH Plus Bioceramic and EndoCeramic sealers: An in vitro study

Abstract Context: Effect of three different obturation techniques on bond strength of bioceramic sealers. Aim: This study aimed to investigate the effect of cold lateral compaction, thermafil, and thermoplasticized obturation techniques on the push-out bond strength of AH Plus Bioceramic and EndoCeramic sealers. Settings and Design: The design of the study was an in vitro study. Materials and Methods: Forty-two extracted teeth that were single-rooted and had fully developed apices were chosen, decoronated, and biomechanically prepared using rotary nickel–titanium (NiTi) instruments. Samples were divided into two groups of n = 21. Group 1: AH Plus Bioceramic sealer, Group 2: EndoCeramic sealer. Then, based on the obturation technique employed, each group was divided into three subgroups (n = 7): subgroups 1a, 2a: Cold lateral compaction; Subgroups 1b, 2b: Thermafil; and Subgroups 1c, 2c: Thermoplasticized (obtura). Using universal testing machine, slices from the middle third of the sample’s root were analyzed to determine the push-out bond strength values. Results: Compared to other groups push-out bond strength was noticeably higher for the cold lateral compaction technique with EndoCeramic sealer (Subgroup 2a), followed by the Thermafil technique with EndoCeramic sealer (Subgroup 2b). Conclusions: In the present study, compared to heat-based obturation techniques, cold lateral compaction showed better push-out bond strength values for both sealers. EndoCeramic sealer resulted in greater push-out bond strength values than AH Plus Bioceramic sealer.

Impact of different disinfection protocols on the bond strength of NeoMTA 2 bioceramic sealer used as a root canal apical plug (in vitro study)

IntroductionTreatment of an immature permanent tooth required a special disinfection protocol due to the presence of thin radicular walls, which are prone to fracture. Mineral Trioxide Aggregate (MTA) has been proposed as a root repair material for root canal treatment. The aim of this in vitro study was to compare the push-out bond strength of conventional White MTA cements and second generation NeoMTA 2 in imitated immature roots treated with different disinfection protocols, which are 5.25% sodium hypochlorite (NaOCl), followed by 17% ethylenediaminetetraacetic acid (EDTA), and NaOCl, followed by 20% etidronic acid (HEBP).MethodsThe root canals of freshly extracted single-root teeth were manually prepared until 90 K-file to imitate immature roots. Roots were randomly divided into four groups (G) according to the disinfection protocol (n = 15 per group). where G1 (NaOCl + EDTA + White MTA) and G2 (NaOCl + EDTA + NeoMTA 2) While G3 (NaOCl + HEBP + White MTA) and G4 (NaOCl + HEBP + NeoMTA 2) All groups were activated with manual agitation. All specimens were incubated for 48 h. The apical third of each root was perpendicularly sectioned to attain a slice of 3 mm thickness. Push-out bond strength values were assessed using a two-way ANOVA and a Student’s t test.ResultsG3 and G4 that were treated with HEPB showed higher significant push-out bond strength mean values than G1 and G2 treated with an EDTA chelating agent. Irrespective of the chelating agent used, it was found that both NeoMTA 2 and White MTA had no significant influence on push-out bond strength mean values (p ≤ 0.05).ConclusionThe combined use of 5.25% NaOCl and 20% HEBP increased the push-out strength values of both NeoMTA 2 and White MTA, rendering them suitable to be used as an alternative chelating agent to EDTA.

Comparative evaluation of blood contamination on the push-out bond strength of mineral trioxide aggregate, Biodentine, and bone cement in furcation perforation repair: An in vitro study

ABSTRACT Aim: This in vitro study was designed to compare the effect of blood contamination on the push-out bond strength of mineral trioxide aggregate (MTA), Biodentine, and bone cement. Materials and Methods: Seventy-eight human mandibular molars with furcation were selected and decoronated at the cementoenamel junction. The samples were mounted 3 mm below the furcation area into the acrylic resin. A perforation in the center of the furcation was made using a round carbide bur size 3 with a diameter of 1.2 mm. Then, the perforation was enlarged up to a standardized diameter of 1.3 mm using a size 5 Gates-Glidden drill. The samples were randomly divided into three groups. Based on blood contamination status, each group (n = 26) was further subdivided into two subgroups (n = 13). Whole fresh human blood was obtained from the principal investigator of the research group. A 27-gauge syringe was used to inject blood into the perforated furcal area. A piece of gelatin was packed under the furcal area using a condenser. MTA, Biodentine, and bone cement were mixed according to the manufacturer’s recommendations and compacted into the perforation. A universal testing machine was used to evaluate the push-out bond strength. Statistical Analysis: The results were analyzed using one-way analysis of variance followed by Tukey’s post hoc test (P &lt; 0.05). Results: In the experimental groups with blood contamination, Group 2A exhibited statistically significant push-out bond strength values compared with Group 1A and Group 3A. In the groups without blood contamination, Group 2B showed statistically significant push-out bond strength values compared with Group 1B and Group 3B. Irrespective of the blood contamination status, Group 3 exhibited higher push-out bond strength values than Group 1, with no statistically significant difference between the groups. No significant difference was observed within the groups. Conclusion: Biodentine showed promising results as a better perforation repair material irrespective of the status of blood contamination. Bone cement can be a viable alternative material for furcation perforation repair compared with MTA.

Comparative In Vitro Analysis of Push-Out Bond Strength of Different Root Canal Sealers to Root Dentin

ABSTRACT Aim: The study’s objective is to assess the bond strengths of four different endodontic sealers to root dentin using a push-out test technique. Material and Method: Sixty single-rooted teeth were selected and decoronated. Canal instrumentation was done using rotary files and divided into four groups (n = 15) based on the sealer used. Group 1: zinc oxide eugenol (ZOE)-based, Group 2: epoxy resin-based, Group 3: methacrylate-based, and Group 4: bioceramic. Following obturation with Gutta Percha, each tooth was prepared with root portions that were 2 mm thick at the apical and middle 1/3 so that universal testing equipment could measure the push-out bond strength. Tukey’s post hoc tests and one-way ANOVA were used to examine the data. Result: According to the results, group 4 had the strongest push-out relationship, followed by groups 3, 2, and 1, respectively. It can be concluded that the bioceramic sealers have superior bond strengths. Conclusion: Bioceramic sealers demonstrated the highest bond strengths to root dentin, outperforming methacrylate, epoxy resin, and zinc oxide eugenol sealers in the push-out test.

The Push-Out Bond Strength, Surface Roughness, and Antimicrobial Properties of Endodontic Bioceramic Sealers Supplemented with Silver Nanoparticles.

This study evaluated push-out bond test (POBT), surface roughness, and antimicrobial properties against Enterococcus faecalis of bioceramic sealers supplemented with silver nanoparticles (AgNPs). The sealers tested were CeraSeal®, EndoSequence® BC SealerTM, and Bio-C® Sealer. The POBT was measured with a Universal Testing Machine, and the type of failure was evaluated with a stereomicroscope. The roughness average (Sa) and peak-valley height (Sy) values were evaluated by atomic force microscopy. The bacterial growth inhibition was evaluated using a disk diffusion test, and antimicrobial activity was determined with the plate microdilution method. The POBT showed no significant difference between sealers with and those without NPs in cervical and apical thirds (p > 0.05). In the middle third, the adhesion force was significant for Endosequence BC Sealer® (p < 0.05). The results showed that the Sa and Sy parameters, when AgNPs were added, did not show a statistically significant difference compared to the groups without nanoparticles (p > 0.05). All tested sealers showed bacterial growth inhibition, but no significant difference was found. Their efficacy, in descending order of antibacterial activity when AgNPs were added, is as follows: EndoSequence® BC SealerTM > Bio-C® Sealer > CeraSeal®. The incorporation of AgNPs into bioceramics improves antimicrobial activity without affecting mechanical properties.

Comparative Evaluation of the Effect of Various Irrigating Solutions on the Push-Out Bond Strength of Biodentine and Mineral Trioxide Aggregate: An In Vitro Study

Introduction: A successful endodontic treatment is ba¬sed on combination of adequate instrumentation, irrigation and obturation of canal system. The objectives of endodontic irrigants are lubrication of root canal, removal of microorganisms, pulp, dentinal remnants and dissolution of tissues. The objective of root-end filling is establishment of proper apical hermetic seal. Aim: To evaluate and compare the effect of various irrigating solutions on push-out bond strength of Biodentine and Mineral trioxide aggregate (MTA). Materials and Method: Sixty-four extracted human single rooted teeth were decoronated 1.5-2 mm coronal to cemento-enamel junction. The root canals were prepared and divided into four groups (n=16): Group I- Normal Saline (Control group), Group II- Triple antibiotic solution, Group III- 2% Chlorhexidine, Group IV- Morinda citrifolia solution. Mid root dentin was sectioned horizontally and irrigated further with respective irrigating solutions for 5 minutes and divided into 2 subgroups: Subgroup A- Biodentine and Subgroup B- MTA. The root-end filling material was incrementally placed and embedded in acrylic blocks. Samples were tested for push-out bond strength using universal testing machine. Results: The highest push-out bond strength was shown by 2% Chlorhexidine group when used with Biodentine and lowest when normal saline was used with Biodentine. Conclusion: All experimental irrigating solutions increased the push-out bond strength of MTA and Biodentine.

Effect of different chelators on the push-out bond strength of hydraulic cements in retrograde obturation.

This study examined the effect of ethylenediaminetetraacetic acid (EDTA) and etidronic acid (HEDP) in retrograde cavities on the bond strength of MTA Angelus and NeoPutty. Sixty-six teeth with single roots and canals were decoronated and enlarged up to F3 using the ProTaper Universal file system. After removing the apical 3 mm within the scope of endodontic surgery procedures, retrograde cavities were prepared with ultrasonic tips. The teeth were divided into three main groups according to the irrigation solution used: saline, 17% EDTA, and 9% HEDP. Following the irrigation of retrograde cavities, each main group was further divided into two subgroups in terms of using MTA Angelus and NeoPutty as retrograde filling materials. Bond strength values of hydraulic cements were measured by the push-out test. Fracture modes were examined under a stereo microscope. Two dentin sections from each group were examined under scanning electron microscopy (SEM) to observe dentinal tubules. Two-way ANOVA and post hoc Tukey tests were used to analyze the data. Irrigation solutions similarly affected the bond strength values of hydraulic cements (P=0.115). MTA Angelus showed significantly higher values than NeoPutty in all the solution groups (P=0.34). Adhesive and cohesive fracture modes were mostly observed in the MTA Angelus and NeoPutty groups, respectively. EDTA, HEDP, and saline had a similar effect on the bond strength of hydraulic cements. The higher bond values of MTA Angelus compared to NeoPutty could support its safe use in endodontic surgery procedures.

Effect of calcium hydroxide and calcium hydroxide nanoparticles used as intracanal drugs after manual and ultrasonic removal on the bond strength of a new sealer with a pozzolan base (Endoseal mineral trioxide aggregate)

ABSTRACT Aim: The adhesion ability of filling materials to the root canal wall can be affected by the intracanal medicaments. The present study investigated the effect of pretreatment with nano-calcium hydroxide and calcium hydroxide on the bond strength of Endoseal mineral trioxide aggregate (MTA) to root canal dentin. Materials and Methods: Fifty maxillary incisor teeth were randomly divided into two experimental groups (n = 20) and a control group (n = 10) after decoronation near the cementoenamel junction and root canal instrumentation according to the type of intracanal medicament (calcium hydroxide and nano-calcium hydroxide). Each experimental group was divided into two subgroups based on manual and ultrasonic drug removal methods. After removing intracanal medicaments and irrigating them, all the groups were obturated with gutta-percha and Endoseal MTA sealer. Then, the samples were sectioned into cross-sections with a thickness of 2 mm using a diamond disc, and the push-out bond strength test was performed on them. Results: The results showed no significant difference in the mean Endoseal MTA bond strength in terms of the type of intracanal medicament and the method used to remove it from the canal (P &gt; 0.05). Conclusion: Using the ultrasonic method compared to the manual method in removing intracanal medicament resulted in no significant difference in the strength of the Endoseal MTA bond. Furthermore, the effect of nanoparticle calcium hydroxide on Endoseal MTA bond strength was not different compared to the conventional type of this medication.

Microhardness and Pushout Bond Strength of Glass Fiber Post-to-Canal Dentin Irrigated with Boric Acid, Nd: YAP, AgNPs, and Curcumin Activated with Microbubble Emulsion. A SEM, EDX Analysis

This study aimed to assess the microhardness (MH) and push-out bond strength (PBS) of fiber post-to-canal dentin when boric acid (BA), Nd: YAP, silver nanoparticles (AgNPs), and microbubble emulsion (MBE) with curcumin were used as irrigants. Canal therapy was performed and the post space was prepared. Prior to glass fiber post (GFP) insertion, the post space was irrigated using 2.5% NaOCl+17% EDTA, 10% BA+EDTA, Nd: YAP laser+EDTA, AgNP+EDTA, and MBE (curcumin)+EDTA. Following disinfection, microhardness was evaluated. GFP was then inserted and PBS was assessed at the coronal, middle, and apical levels, along with the examination of debonded surfaces via stereomicroscope. The data were analyzed using ANOVA and a Post Hoc Tukey HSD test. The results showed that MH was highest in the group treated with AgNP+EDTA and lowest in the group treated with 10% BA+EDTA. Within the cervical region, the Nd: YAP laser+EDTA group showed the lowest PBS, while the highest PBS was observed in the group treated with MBE (curcumin)+EDTA. In the middle region, the GFP bonded to canal dentin disinfected with 2.5% NaOCl+EDTA was comparable to that treated with Nd: YAP laser+EDTA. In the apical region, the PBS of GFP was highest in the canal disinfected with MBE (curcumin)+EDTA. The study concluded that silver nanoparticles+EDTA and curcumin photosensitizer via microbubble emulsion+EDTA have the potential to be used as alternatives to conventional methods for improving the adhesion of glass fiber post-to-canal dentin, along with enhancing microhardness.

Comparative analysis of an epoxy resin-based and a premixed calcium silicate-based sealer's push-out bond strength with and without incorporation of chitosan nanoparticles: An in vitro investigation.

The aim of the study was to compare and evaluate the push-out bond strength (POBS) of epoxy resin-based and calcium silicate-based sealers with and without incorporating chitosan nanoparticles (CSNPs). Eighty human mandibular premolars with a single canal were taken. A standard root length of 15 mm was established. Canals were instrumented with Neoendo files up to size 30, 4% and were irrigated with 5 ml of 2.5% NaOCl, and 5 ml of ethylenediaminetetraacetic acid 17%. Then, samples were obturated using the size 30, 4% gutta-percha, single-cone technique using respective sealers. For POBS, it was grouped as Group 1 Adseal, Group 2 CeraSeal, Group 3 Adseal + 2% wt/vol CSNP, and Group 4 CeraSeal + 2% wt/vol CSNP. Samples embedded in acrylic resin were sectioned transversely at 11 and 7 mm from the apex. Dislodgment resistance was calculated using a universal testing machine. The data were analyzed using a one-way ANOVA test, followed by Tukey's post hoc analysis. The level of significance (P value) was set at P < 0.05. At 7 mm from the apex, Group 4 (CeraSeal + 2% wt/vol CSNP) demonstrated significantly higher mean POBS. However, no significant difference was observed between Groups 1 (Adseal), Group 2 (CeraSeal), and Group 3 (Adseal + 2% wt/vol CSNP). At 11 mm from the apex, Group 2 (CeraSeal) and Group 4 (CeraSeal + 2% wt/vol CSNP) demonstrated significantly higher mean POBS. On comparison between POBS at 7 mm and 11 mm from the apex, the mean POBS at the 11 mm region from the apex was significantly higher in all study groups, which was statistically significant. Within the limitations of the study, it has been concluded that Group 4 (CeraSeal + 2% wt/vol CSNP) has better bond strength compared to the other groups.

Influence of Battery Levels in Cordless LED Light-curing Units on Properties of Resin Cement and Glass Fiber Post Retention.

This study aimed to assess the impact of battery levels in single-peak and multi-peak light-curing units (LCUs) on irradiance, and their effects on glass fiber post push-out bond strength to root dentin and the degree of conversion of dual-cure universal resin cement. Sixty bovine roots underwent endodontic treatment and were randomly distributed into 6 groups (n=10), formed by combining two LCUs (single-peak and multipeak) and three battery levels (100%, 50%, and 10%). A spectrophotometer measured irradiance (mW/ cm2) and spectral irradiance (mW/cm2/nm). Push-out bond strength (PBS) tests occurred at three root regions (cervical, middle, and apical), with optical and scanning electron microscopy for failure mode analysis. Degree of conversion (DC) was evaluated across the root regions. Data were analyzed using two-way repeated measures ANOVA and the Tukey HSD test. The Fisher exact test verified failure modes (α=0.05). As multipeak LCU battery levels decreased, emitted irradiance also diminished, with notable PBS reductions in the apical thirds. Failure modes were influenced by different conditions, primarily exhibiting mixed modes. Battery levels significantly impacted DC in the multipeak LCU, particularly in the cervical region, while the single-peak LCU exhibited DC reduction at the 10% battery level in the cervical region. Emitted irradiance, resin cement DC, and glass fiber post bond strength to root dentin may be influenced by varying cordless LCUs and battery levels.

Chitosan nanoparticles, Rose Bengal-chitosan activated photodynamic therapy as final irrigant on pushout bond strength, smear layer removal efficacy and antibacterial effectiveness against E.faecalis

AimImpact of final root canal disinfectants diode laser (DL), Rose Bengal photosensitizer (RBP), Chitosan Nanoparticles (CNPs), and CNPs modified RBP on Enterococcus faecalis (E.faecalis) survival rate, smear layer (SL) removal efficacy and push out bond strength (PBS) of resin sealer to the radicular dentin. Material and methodSingle rooted seventy-five human mandibular premolar teeth were sectioned at a level of cementoenamel (CEJ) and root canal treatment was performed using a ProTaper rotary instrument. To assess the antibacterial efficiency E.faecalis inoculation was performed using a pour plate method. The samples were arbitrarily allocated into five groups based on the final disinfectant received (n = 15) Group-1 (NaOCl+17 % EDTA), Group-2 (NaOCl+DL), Group-3 (NaOCl+CNPs), Group-4 (NaOCl+RBP activated by DL) and Group-5 (NaOCl+CNPs-RBP activated by DL). SEM analysis for SL removal was performed on five specimens from each group. Root canal obturation and sectioning were performed at cervical, middle, and apical levels. PBS and failure mode were analyzed using a universal testing machine (UTM) and stereomicroscope respectively. The data was subjected to analysis using one-way analysis of variance (ANOVA) and Tukey's post hoc test. ResultGroup 1 (NaOCl+17 % EDTA) (0.36 ± 0.01 CFU/mL) unveiled the maximum survival rate of tested bacteria. However, Group 5 (NaOCl+CNPs-RBP activated by DL) (0.11 ± 0.01 CFU/mL) displayed minimum survival of E.faecalis. The highest SL removal (1.44 ± 0.11) and bond integrity scores (12.23 ± 0.24 MPa) were recorded in the coronal section of Group 5 (NaOCl+ CNPs-RBP activated by DL) treated roots. However, the lowest removal of SL (3.15 ± 1.09) and PBS (7.24 ± 0.09 MPa) were recorded in Group 4 (NaOCl+RBP activated by DL) treated canals. CONCLUSIONCNPs-RBP activated by DL as the final irrigant provided satisfactory antibacterial activity, SL removal, and bond strength outcomes compared to other tested groups.