Extrusion bond strength of glass fiber post to radicular dentin after final irrigation using MTAD, EDTA, Pineapple peel extract, and riboflavin

Photochemically Activated Microbubble Emulsion, Nd: Yap Laser, and Cerium Oxide Nanoparticles as Canal Disinfectants on Push-Out Bond Strength of Sealer to Root Dentin, Smear Layer, and Antibacterial Efficacy

Effect of different root canal irrigation regimes microbubble emulsion (MBE) via riboflavin photosensitizer (RFP), cerium oxide (CeO2) nanoparticles (NPs), and Nd: YAP laser on antibacterial efficiency, microhardness (MH), smear layer (SL) removal efficacy, and push-out bond strength (PBS) of AH plus sealer to canal dentin. Sixty single-rooted teeth were selected, disinfected, and categorized into four groups based on the type of disinfection. Following disinfection, a pair of samples were randomly selected and visualized under scanning electron microscope (SEM) for SL evaluation. Three samples from each disinfection group were mounted on a Vickers MH tester for hardness testing. A brain-heart infusion (BHI) agar plate was inoculated with a single colony of Enterococcus faecalis ( E. faecalis), and their survival rate was measured following different disinfecting regimes. The remaining samples were filled with gutta-percha (GP) and sectioned to evaluate PBS via universal testing machine (UTM), followed by failure analysis. Data were analyzed using analysis of variance (ANOVA) and Tukey's post hoc test. The survival rate of E. faecalis was lowest for Group 3 (0.11 CFU/mL) with the highest MH values (49.72 ± 1.02 N/mm2). The PBS was highest for Group 3 cervical (11.54 ± 0.49 MPa) and middle third (11.12 ± 0.50 MPa). SL removal efficacy was comparable in groups 3 and 4 at the coronal and middle third. The application of CeO2NPs as a canal irrigant in conjunction with EDTA resulted in enhanced bond values, demonstrating superior SL removal capabilities. This type of disinfection notably enhances the MH of canal dentin while demonstrating significant sterilization efficacy against E. faecalis .

Efficacy of canal disinfectants Temoporfin, carbon nanoparticles, and Er: YAG laser on martens hardness, smear layer removal, and bond strength of glass fiber posts to canal dentin

AIM

To investigate the effectiveness of unconventional post space disinfection techniques, specifically Er:YAG laser, Temoporfin, and Carbon Nanoparticles (CNPs), in improving Martens hardness (MH), eliminating the smear layer (SL), and enhancing the push-out bond strength (PBS) of glass fiber posts in canal dentin.

METHODS

An in vitro study was conducted utilizing 80 single-rooted extracted human teeth, which were decoronated and subjected to standardized root canal preparation. The teeth were equally distributed into four experimental groups: Group 1 (NaOCl + EDTA), Group 2 (Er: YAG laser + EDTA), Group 3 (Temoporfin + EDTA), and Group 4 (CNPs + EDTA). Each group underwent disinfection protocols followed by assessment of Martens hardness (MH) using nanoindentation testing, SL evaluation via scanning electron microscopy, and bond strength testing using a universal testing machine (UTM). Statistical analysis was performed using one-way ANOVA followed by Tukey's post hoc test to determine the level of significance among the groups. A significant level of p<0.05 was established.

RESULTS

Group 4 (CNPs+17 % EDTA) showed a high MH value of (0.25 ± 0.02 GPa), significantly outperforming Groups 1 (0.13 ± 0.02 GPa) and 3 (0.10 ± 0.03 GPa). Group 2 (Er: YAG laser + 17 % EDTA) demonstrated superior smear layer removal across all sections, particularly in the apical third (1.94 ± 0.38). Push-out bond strength was highest in Group 2 (9.98 ± 0.14 MPa at the cervical level) and Group 4 (10.08 ± 0.21 MPa), while Group 1 showed a decrease in apical bond strength of (5.11 ± 0.19 MPa) CONCLUSION: CNPs and Er:YAG laser treatments, in comparison to Temoporfin and NaOCl, significantly increase dentin hardness and bond strength while reducing SL. This finding suggests that the incorporation of these innovative disinfection methods into endodontic procedures may enhance the durability and success of glass fiber post restorations.

Post-Space Disinfectants With Sodium Hypochlorite and Methylene Blue Loaded in Silver and Quartz Nanoparticles Activated by Photodynamic Therapy. A SEM Analysis

Post-space disinfectants methylene blue loaded with silver (Ag) and Quartz nanoparticles (NPs) and MB alone activated by photodynamic therapy (PDT) on the survival of Enterococcus faecalis, smear layer (SL) removal efficacy, and extrusion bond strength (EBS) of fiber posts to canal dentin. Hundred mandibular premolars underwent root canal treatment using the rotary ProTaper system. The canals were obturated and post-space was prepared up to a length of 8 mm, maintaining a 5 mm seal. To assess antibacterial efficacy E. faecalis were inoculated in the canal (n = 20). The samples were then randomly allocated into four groups according to the canal disinfectant used to sterilize the canals. Group 1: 2.5% NaOCl+17% EDTA, Group 2: MB-PDT, Group 3: MB@QP-PDT, and Group 4: MB@AgNP-PDT (n = 25). SEM analysis was conducted on five samples from each disinfectant group to assess the removal of the SL. Survival rates were calculated (n = 5 from each group). Glass fiber post (GFP) was cemented to the root dentin of the remaining samples followed by artificial aging. Sectioning of the specimens was performed in all three-thirds of the canals. PBS was assessed followed by failure evaluation. ANOVA and Tukey post hoc test were used to compare the E. faecalis survival rate and PBS of fiber post among different investigated groups. Group 4 (MB@AgNP-PDT) treated canals exhibited the minimum survival rate (0.30 ± 0.04 CFU/mL) of E. faecalis and maximum PBS. However, the highest survival rate and minimum bond strength of GFP were observed in Group 1 (NaOCl+17% EDTA) and Group 2 (MB-PDT) treated teeth respectively. The highest SL removal was recorded in the coronal section of the samples of Group-4 disinfected with MB@AgNP-PDT. The lowest removal of SL was recorded in Group 2 samples sterilized with MB-PDT at apical one-third. Silver nanoparticles when utilized as nano-carriers to enhance the efficiency of MB activated by PDT, have been shown to exhibit the highest antimicrobial potency, improved capacity for SL removal and improved PBS.

Contemporary Concepts of Adhesive Cementation of Glass-Fiber Posts: A Narrative Review

(1) Background: Cementation of glass fiber posts to root canals has been associated with various failures, especially debonding. This narrative review aims to present the contemporary concepts concerning the adhesive cementation of glass fiber post and to discuss the optimal management of these factors. (2) Methods: Electronic search was performed in MEDLINE/Pub Med and Google Scholar using selected keywords examining the parameters post length, surface treatment of glass fiber posts, post space preparation and dentin pretreatment, resin cement selection, adhesive systems and hybrid layer formation, and clinical techniques. (3) Results: The search led to the selection of 44 articles. Epoxy resin-based endodontic sealers are recommended and the use of temporary cement in the root canal should be avoided. The minimum length of a glass fiber post adhesively cemented to a root canal is 5 mm. Irrigating the root canals with chlorhexidine, MTAD, or EDTA (alone or in combination with NaOCl) after post space preparation seems to enhance the bond strength. Silane application on the surface of the post seems to be beneficial. Concerning resin cements and adhesive systems, the results were rather inconclusive. Finally, resin cement should be applied inside the root canal with an elongation tip and photoactivation should be delayed. (4) Conclusions: Contemporary concepts of adhesive cementation of glass fiber posts can indeed improve the bond between glass fiber posts, resin cement, and root canal dentin, however, evidence coming from long-term randomized prospective clinical trials is needed in order to obtain safer conclusions.

Effect of canal medicaments triple antibiotic paste, Bio-C Temp, and Nano-silver gel activated by visible blue light on canal dentin microhardness and extrusion bond strength of AH plus sealer: A SEM and EDX analysis

AIM

Assessment of contemporary canal medicaments (Triple antibiotic paste (TAP), Bio-C Temp, and Nano silver gel activated by visible blue light on the dentin microhardness (MH) and push-out bond strength (PBS) of AH plus endodontic sealer.

METHOD

Sixty extracted premolars were obtained and decontaminated. Canal cleaning and shaping were performed. The samples were randomly allocated into four groups based on the intracanal medicaments. Group 1= CH paste, Group 2= TAP, Group 3= Bio-C Temp, and Group 4= Nano-silver gel activated by visible blue light. MH assessment was performed using a Vickers Microhardness tester. Forty specimens, ten from each group underwent root canal obturation. PBS and failure mode evaluation were performed. ANOVA and Post Hoc Tukey test were utilized to conduct intra and inter-group comparisons.

RESULTS

The maximum outcome of surface hardness was presented by Group-3 (Bio-C Temp®) specimens. However, minimum scores of MH were displayed by Group 1 (CH) treated teeth. The highest outcomes of EBS were exhibited by the cervical third of Group 3 (Bio-C Temp®) samples. The apical section of Group 4 Teeth with Nano Silver gel activated by visible blue light revealed the lowest scores of bond integrity.

CONCLUSION

Bio-C Temp and TAP proved to be better intracanal medicament than other tested groups in terms of the push-out bond strength of the sealer. TAP displayed lower microhardness as compared to the Bio-C Temp.

Effect of reapplication on pull-out bond strength of fibre post to root dentin: An in vitro study

Purpose

Post removal may be necessary for many reasons and is inevitable after the re-application of a dental post. The present study investigated the bond strength between root dentin and a re-applied fibre-reinforced composite (FRC) post by a pull-out test.

Materials and methods

After root canal treatments of 30 extracted human maxillary canine teeth, post spaces were prepared (10 mm), and FRC posts (Hi-Rem Post; Overfibres, İmola, Italy) were luted with self-adhesive resin cement. The samples were than randomly divided into test and control groups (n = 15 in each). The FRC posts were removed in the test group, and new posts were cemented. The pull-out test (1 mm/minute speed) was used to measure the bond strength. Failure types were determined using a stereomicroscope. Mann-Whitney U, chi-square and Fisher-Freeman-Halton exact tests were used for statistical analysis.

Results

The bond strength values of the test (119.5 ± 36.86 N) and control (115.55 ± 55.44 N) groups did not differ significantly (p >.05). In terms of the percentage of failure types, there was a significant difference only in the test group between the mixed failure type and the other failure types (p <.05).

Conclusions

The re-application of FRC post did not seem to affect the bond strength. The distribution of failure types was similar between the control and test groups.

Use of final irrigants MTAD, Salvedora Perscia, Malachite green, and Ti-sapphire laser on push-out bond strength of Zirconia post

AIM

Evaluation of the push-out bond strength (PBS) of zirconia post-bonded to radicular dentin after using different final irrigants (MTAD, Malachite green (MG), Ti-sapphire laser and Salvadora persica (S.persica).

MATERIAL AND METHOD

Forty human permanent single-rooted were decoronated above the cement-enamel junction. An experienced endodontist performed all the root canal instrumentation using ProTaper universal rotary files. Canals were irrigated using 5.25% NaOCl solution followed by EDTA as a final sterilant. Obturation with gutta-percha using AH Plus sealer was performed. Post-space preparation was completed using Gates Glidden and specimens were randomly assigned to four groups based on the final disinfectant received (n=10). Group 1: 5.25% NaOCl + MTAD, group 2: 5.25% NaOCl + MG, group 3: 5.25% NaOCl +Ti-sapphire laser, and group 4: 5.25% NaOCl + S. persica. The chemically polymerized resin was used to lute zirconia posts. PBS and failure mode analysis were performed using a universal testing machine and stereomicroscope at 40X magnification. Data were compared between the two groups with 95% CI using one-way analysis of variance (ANOVA) with the Tukey post hoc test. p=0.05.

RESULTS

Group4(5.25% NaOCl+ S.persica) specimens demonstrated the maximum (8.94±0.14 MPa) bond strength. Conversely, the apical third of Group 2 (5.25% NaOCl+ MG) (2.87±0.15 MPa) samples revealed the minimum bond strength scores. Intergroup comparison exposed that Group 1 (1.3% NaOCl+ MTAD), Group 3 (5.25% NaOCl+Ti-sapphire laser), and Group 4 (5.25% NaOCl+ S. persica) at all three-thirds unveiled no significant difference in PBS (p<0.05).

CONCLUSION

Ti-sapphire laser and Salvedora Persica possess the potential to be used as a final root canal irrigant to improve the push-out bond strength of zirconia post-to-root dentin.

Surface conditioning of PEEK post using Nd: YVO4 laser, Photodynamic therapy, and sulfuric acid on the pushout bond strength to canal dentin

AIM

To assess the push-out bond strength (PBS) of polyetheretherketone (PEEK) post-to-root dentin using post-surface conditioners i.e., Neodymium-doped yttrium orthovanadate (Nd: YVO4) and Riboflavin (RF) and Rose Bengal (RB) mediated photodynamic therapy (PDT) compared to sulfuric acid (SA).

MATERIALS AND METHODS

Decoronation of forty human single-rooted premolar teeth was performed. Followed by chamber opening, working length (WL) was established at 15 mm. Root canal preparation was completed using ProTaper Ni-Ti rotary system till F3 finishing file along with root canal disinfection. The canals were dried with paper cones followed by obturation using gutta-percha (GP) and AH sealer. Post space was prepared by drilling out 11 mm of GP using a Gates Glidden drill #3. PEEK posts were fabricated using the CAD-CAM system and then randomly allocated into 4 groups based on the post-surface conditioning (n=10). Group 1: SA, group 2: PDT RF, group 3: PDT RB, and group 4: Nd: YVO4 laser. The PEEK post was then cemented in their respective canal. PBS and failure mode assessment were performed using a universal testing machine and stereomicroscope at 40x magnification. The SBS data set was subjected to a one-way analysis of variance (ANOVA) and Tukey's Post Hoc test at a significance level of 0.05.

RESULTS

The samples in group 4 (Nd: YVO4 laser) coronal third (7.99±0.24 MPa) demonstrated the highest PBS. The apical third of samples in group 1 PEEK post surface conditioned with SA (5.15± 0.52 MPa) exhibited the minimum values of PBS. Intergroup comparison analysis showed that samples in group 1 (SA), group 2 (RF activated by PDT), group 3 (RB activated by PDT), and group 4 (Nd: YVO4 laser) demonstrated comparable outcomes of bond scores (p>0.05) CONCLUSION: Neodymium-doped yttrium orthovanadate (Nd: YVO4) and riboflavin and Rose bengal activated by photodynamic therapy (PDT) have been investigated as potential alternatives for the surface conditioning of PEEK (polyetheretherketone) posts.