In Vitro Assessment of SWEEPS and Antimicrobial Photodynamic Therapy Alone or in Combination for Eradicating Enterococcus faecalis Biofilm in Root Canals

OBJECTIVES

This study investigates the efficacy of antimicrobial photodynamic therapy (aPDT) using riboflavin and a blue diode laser (BDL), combined with shock wave-enhanced emission photoacoustic streaming (SWEEPS), against Enterococcus faecalis.

MATERIALS AND METHODS

A total of 48 extracted single-rooted human teeth were used. The root canals were instrumented, sealed at their apices, had the smear layer removed, and then underwent autoclave sterilization. Subsequently, each canal was inoculated with E. faecalis bacterial suspension and allowed to incubate for ten days. After confirming the presence of biofilms through scanning electron microscopy (SEM) in three teeth, the remaining teeth were randomly allocated into nine groups, each containing five teeth: control, 5.25% sodium hypochlorite (NaOCl), BDL, SWEEPS + normal saline, SWEEPS + NaOCl, riboflavin, riboflavin + SWEEPS, riboflavin + BDL, and riboflavin + BDL + SWEEPS. After the treatment, the numbers of colony-forming units (CFUs)/mL were calculated. The data were analysed using one-way ANOVA followed by Tukey's test for comparisons.

RESULTS

All groups, with the exception of the BDL group, exhibited a significant reduction in E. faecalis CFU/mL when compared to the control group (p < 0.001). The difference in CFU/mL value between riboflavin + BDL + SWEEPS and riboflavin + SWEEPS was significant (p = 0.029), whereas there was no significant difference between riboflavin + BDL + SWEEPS and riboflavin + BDL (p = 0.397). Moreover, there was no statistically significant difference between the riboflavin + SWEEPS group and the riboflavin + BDL group (p = 0.893).

CONCLUSIONS

The results demonstrated that combining the SWEEPS technique with riboflavin as a photosensitizer activated by BDL in aPDT effectively reduced the presence of E. faecalis in root canals.

Antimicrobial and Antibiofilm Activity of Synthetic Peptide [W7]KR12-KAEK Against Enterococcus faecalis Strains

The emergence of infections caused by microorganisms in the oral cavity and increasing concerns regarding the use of antibiotics have resulted in the development of novel antimicrobial molecules, such as antimicrobial synthetic peptides. The purpose of this study was to evaluate the antimicrobial and antibiofilm activities of the native peptide KR-12 and its derivative, the synthetic peptide [W7]KR12-KAEK, against planktonic and biofilms Enterococcus faecalis strains. The methods used to evaluate the antimicrobial activity in planktonic cultures include minimum inhibitory concentration and minimum bactericidal concentration assays. The effects of [W7]KR12-KAEK on biofilm formation and mature biofilms were evaluated by quantifying biomass (crystal violet staining) and counting colony-forming units. Structural assessments of the biofilms and cellular morphological changes were performed using scanning electron microscopy. Peptide [W7]KR12-KAEK showed potential antimicrobial activity against planktonic cells. Interestingly, the native peptide KR-12 showed no antimicrobial activity. Moreover, it inhibited biofilm formation and disrupted the mature biofilms of E. faecalis strains. These results suggest that [W7]KR12-KAEK may be a potential molecule for the development of auxiliary antimicrobial therapies against oral infections.

Efficacy of Shock Wave-Enhanced Emission Photoacoustic Streaming (SWEEPS) in the Removal of Different Combinations of Sealers Used with Two Obturation Techniques: A Micro-CT Study

This study sought to evaluate the efficacy of SWEEPS in the removal of epoxy-resin-based and calcium-silicate-containing endodontic sealer combined with single-cone and carrier-based obturation techniques through a micro-CT analysis. Seventy-six single-rooted extracted human teeth with single root canal were instrumented with Reciproc instruments. Specimens were randomly divided into four groups (n = 19) according to the root canal filling material and obturation technique: (1) AH Plus sealer + Reciproc gutta-percha, (2) TotalFill BC sealer + TotalFill BC Points, (3) AH Plus sealer + Guttafusion obturator, and (4) MTA Fillapex + Guttafusion obturator. All specimens were re-treated one week later using Reciproc instruments. Following re-treatment, root canals were additionally irrigated using the Auto SWEEPS modality. The differences in the root canal filling remnants were analyzed by micro-CT scanning of each tooth after root canal obturation, after re-treatment, and after additional SWEEPS treatment. Statistical analysis was performed using an analysis of variance (p < 0.05). The additional treatment with SWEEPS significantly reduced the volume of the root canal filling materials in all experimental groups compared to the removal of root canal filling using only reciprocating instruments (p < 0.05). However, the root canal filling was not removed completely from any of the samples. SWEEPS can be used to enhance the removal of both epoxy-resin-based and calcium-silicate-containing sealers, in combination with single-cone and carrier-based obturation techniques.

Effect of different irrigation activation techniques on irrigation penetration into the simulated lateral canals

This study, in which a hundred human teeth with single straight canal were used, focused on the evaluation of contrast solution penetration ability into the simulated lateral canals activated by XP-endo Finisher (XPF), EDDY, Nd:YAG, and Er:YAG laser systems with three different observation methods. The root canals were prepared up to X4 at working length using the ProTaper Next system. The teeth were decalcified and simulated lateral canals were created with #8 K-file at 2, 4, and 6 mm levels. Then the teeth were cleared using methyl salicylate and divided into 5 equal groups according to irrigation activation techniques (CSI, XPF, EDDY, Nd:YAG, and Er:YAG laser). After the contrast solution was activated, images of the simulated lateral canals were obtained by a dental microscope, digital radiography, and CBCT. The contrast solution penetration scores at the 2, 4, and 6 mm levels according to irrigation activation techniques and observation methods were analyzed statistically using Kruskal-Wallis non-parametric analysis of variance Bonferroni test post hoc comparisons. With the other 2 parameters are ignored, the highest and lowest contrast solution penetration were observed at 6 and 2 mm simulated lateral canal levels (p < 0.05), in Er:YAG irrigation activation and CSI technique (p < 0.05), and in direct visual and digital radiographic observation method (p < 0.05), respectively. Within the limits of this study, it was determined that the contrast solution penetration into the simulated lateral canals decreased from the coronal to the apical and achieved with the most effective Er:YAG laser activation technique. In addition, direct visual observation was found to be the best method for the assessment of contrast solution penetration.

Current Trends in Irrigation Solution and Adjunct Use During Endodontic Therapy Among Dental Professionals in Jeddah, Saudi Arabia: A Cross-Sectional Study

Introduction  Chemical irrigation is a crucial component of endodontic therapy, and irrigation adjuncts increase the efficiency of non-surgical root canal system disinfection, reduce microbial loads, and enhance the penetration of irrigants throughout the root canal system. This study aimed to determine the current trends in chemical irrigation and its adjunct use during root canal therapy by general dental practitioners (GDPs) and endodontic specialists in both government and private sectors in the city of Jeddah, Saudi Arabia. Methods This cross-sectional study used a self-administered survey sent to GDPs and endodontic specialists in both government and private sectors in the city of Jeddah, Saudi Arabia. Responses were accepted from November 2019 till May 2020. The survey was randomly distributed to consenting participants. The results are presented using descriptive statistics. Results A total of 302 participants responded to the survey, with a 44% response rate. The majority of responses were from GDPs (54%), while 46% were from endodontic specialists. Regarding the workplace, 59% of respondents were public sector professionals, 25% were private sector professionals, and 16% were both public and private sector professionals. Around 30% of the respondents used sodium hypochlorite (NaOCI) as their primary irrigation solution during root canal treatment, with 52% using it at its full-strength concentration and 18% and 17% preferring to use it in combination with Ethylenediaminetetraacetic acid (EDTA) only or EDTA and saline, respectively. When asked to rank the reasons for choosing their irrigant of choice during therapy; antibacterial capability and tissue dissolution were the most crucial factors to 80% and 57% of participants, respectively. Half of the respondents irrigated the canal to 2 mm from the apex and 21% irrigated to 1 mm from the apex. Three-quarters of participants aimed to remove the smear layer during root canal treatment. Only 47% of respondents used adjuncts to irrigation, and 71% reported that their choice of irrigation solution would differ depending on whether the apex is open or closed. Conclusion Most respondents used full-strength NaOCI concentration as the main irrigation solution and routinely removed the smear layer during root canal treatment. Only 47% of respondents used irrigation adjuncts such as ultrasonics.

Effect of Endodontic Irrigating Solutions on Radicular Dentine Structure and Matrix Metalloproteinases-A Comprehensive Review

Irrigating solutions play an important role in the eradication of intracanal microbes and debris dissolution during endodontic treatment. Different combinations of solutions and protocols have been advocated, with sodium hypochlorite (NaOCl), ethylenediamine tetra acetic acid (EDTA), and chlorhexidine (CHX) remaining the most widely used ones by many clinicians. Although these solutions provide efficient inorganic dissolution and antimicrobial capacity, their use has also been reported to cause undesired effects on root dentin composition and mechanical and biomechanical properties, such as microhardness, surface roughness, bond strength, and matrix metalloproteinase (MMP) activity. Several corroborating studies attribute these changes in mechanical properties of dentine to the use of irrigating solutions, and there are limited reports on how the solutions affect the expression of MMPs, which may be a correlating link to understanding the role of these enzymes in dentin collagen and changes in the mechanical properties of dentin. Hence, using the basis of several studies from the literature, the objective is to comprehensively review the influence of individual and combined irrigating solutions on root dentine structure and the activity of the MMPs.

Evaluation of the Antibacterial Efficacy of QMix and AgNP Solutions in Root Canals of Primary Molars: An In-Vitro Study

Purpose

The study aimed to evaluate QMix²ⁱⁿ¹ and silver nanoparticles (AgNPs) solution in eliminating Enterococcus faecalis (E. faecalis) bacteria within root canals of primary molars.

Materials and methods

The study sample consisted of 45 extracted primary molars, which were divided into three groups: Group 1 (control) NaOCl 5.25%, Group 2 (experimental) QMix^{2 in 1}, and Group 3 (experimental) AgNPs 4000 ppm. The root canals were sterilized within an autoclave and then contaminated with E. faecalis bacteria. The root canals were irrigated for five minutes in a quantity of 3 ml using a 31-gauge irrigation needle, and then bacterial smears were taken.

Results

Sodium hypochlorite, AgNPs, and QMix²ⁱⁿ¹ effectively reduced the bacterial count of Enterococcus within root canals of primary molars. There were statistical differences between all groups. QMix²ⁱⁿ¹ solution showed the greatest antibacterial efficacy, then NaOCl solution and AgNPs solution. 

Conclusion

All irrigation solutions used are effective in eliminating E. faecalis. QMix²ⁱⁿ¹ can be considered a good alternative to sodium hypochlorite in irrigation root canals of primary teeth.

Kök kanal geometrisinin ve iğne tipinin apikalden irrigan taşmasına etkisi: ex vivo çalışma

Objective: The aim was to evaluate the effect of root canal geometry on the amount of apical extrusion of irrigant, by testing different tapers and needle types. Materials and Method: Forty-three extracted single-rooted human mandibular premolar teeth were accessed. Experimental groups were instrumented to produce increasing amounts of taper in each successive group: Group 1 (#25/.02), Group 2 (#25/.04), Group 3 (#25/.06), and Group 4 (#25/.08) (n=43, each). Irrigation was done sequentially by using a 30-G open-ended flat needle, 30-G close-ended side-vented needle, and 27-G open-ended beveled needle. Flat and side-vented needles were each placed 3 mm short of the apex, while the beveled needle was placed as far as possible in the canal without binding. Extruded irrigant was collected in preweighed foam cubes. Statistical significance was set at p&lt;0.05. Results: An increase in canal taper led to a decrease in the amount of extruded irrigant for the flat needle (p&lt;0.05; Groups 1 and 2 versus 3 and 4) and side-vented needle (p&lt;0.05; Groups 1 and 2 versus 4), but no significant effect was found for the beveled needle. The amount of extruded irrigant was greater with the flat than with the side-vented needle at all tapers and with the beveled needle at most tapers (p&lt;0.05). The side-vented needle was generally associated with the least amount of extrusion. Conclusion: Given a constant needle insertion depth, the amount of apically extruded irrigant decreased as canal taper increased. The greatest and least amounts of extrusion were generally observed with the flat and side-vented needle, respectively.

In Situ Zymography Analysis of Matrix Metalloproteinases Activity Following Endodontic Irrigation Protocols and Correlation to Root Dentine Bond Strength

The objective was to evaluate the effect of different root canal irrigating solutions on the activity of matrix metalloproteinases (MMPs), and correlation to the push-out bond strength (PBS) and nanoleakage expression (NL) in the root dentin. Seventy-two single-rooted teeth were treated endodontically and distributed into four groups (n = 6 for in-situ zymography, n = 10 for PBS, and n = 2 for NL per group) according to the irrigating solutions used: (I) saline (S); (II) 5.25% sodium hypochlorite (SH); (III) 5.25% SH + 10% citric acid (CA); and (IV) 5.25% SH + 10% CA + 0.2% chlorhexidine (CHX). After root canal obturation, post space was prepared to receive the glass fiber post. Dual-cure resin was used for luting and light polymerization was performed. The root/fiber post assemblies were sectioned and subjected to in situ zymography, and PBS and NL expression analysis tests. The enzymatic activity was quantified and expressed as a percentage of the green fluorescence, while fractographic evaluation was performed after PBS with a stereomicroscope, and data were statistically analyzed at p < 0.05. The zymography analysis shows high expression of MMPs in the middle third of the root in all groups, while the most abundant activity of MMPs following the irrigating solutions is observed in groups I and III, where saline and citric acid are used, respectively. Inversely, group IV, where chlorhexidine is the final rinse, records the lowest MMP activity with the highest PBS, and the statistical analysis of the groups are ranked as: IV > II > III > I (p < 0.05). The combination of SH, CA, and CHX results in lower expression of MMPs and higher push-out bond strength of fiber posts to root dentin, with no difference seen in the nanoleakage expression (p > 0.05); hence, this irrigation regime with chlorhexidine as a final rinse is more favorable than other combinations in ensuring optimal adhesion to root dentine.

An in vitro radiological evaluation of irrigant penetration in the root canals using three different irrigation systems: Waterpik WP-100 device, passive irrigation, and manual dynamic irrigation systems

Background:

Instrumentation and irrigation of the root canal facilitating effective debridement is considered the most important single factor in the prevention and treatment of endodontic diseases.

Aim:

The aim of the study was to evaluate the depth of penetration of the irrigant depending on the final activation using Waterpik device modified with NaviTip needle, passive irrigation, and manual dynamic activation using the radiopaque solution in conjunction with digital dental radiography.

Materials and Methods:

Ninety freshly extracted single-rooted mandibular premolars based on the inclusion and exclusion criteria were used for this study. Access cavity preparation was done for all the samples, and the working length of each sample was determined using a size 10-k file. The radiopaque solution (Urografin) was delivered into (Groups A, B, and C) prepared canal of samples at the rate of 1 ml in 30 s with up-and-down motion.

Results:

The test results showed that Waterpik WP-100 group showed significantly high infiltration index values as compared to passive irrigation and manual irrigation group at P < 0.002 and P = 0.007, respectively.

Conclusion:

Sonic irrigation using a Waterpik device modified with a NaviTip needle permits better infiltration of the irrigant.

Assessment of Antimicrobial Efficacy of Nano Chitosan, Chlorhexidine, Chlorhexidine/Nano Chitosan Combination versus Sodium Hypochlorite Irrigation in Patients with Necrotic Mandibular Premolars: A Randomized Clinical Trial

AIM: The study was done to assess the antimicrobial effectiveness of Chitosan Nanoparticles (CNPs), Chlorhexidine (CHX), and their combination (CHX/CNPs) versus that of Sodium hypochlorite (NaOCl) in patients with mandibular necrotic premolars and to evaluate their effects on post-operative pain after single-visit endodontic treatment. MATERIALS AND METHODS: Sixty patients with necrotic mandibular premolars were divided randomly to four groups (n = 15) according to the used irrigating solution. Instrumentation was done using rotary ProTaper files. During instrumentation, irrigation was done using 2.5% NaOCl; afterward, canals were flushed with sterile saline. A final flush with the study irrigants was done as follows: 3% CNPs for Group A, 2% CHX for Group B, CHX/CNPs for Group C, and 5.25% NaOCl for Group D. Samples were collected from root canals before and after canal preparation then cultured to assess the number of colony-forming units/ml. All patients were instructed to record their pre- and post-operative pain levels on a numerical rating scale. RESULTS: CNPs and CHX/CNPs were significantly more effective than either CHX or NaOCl; however, there was no significant difference between them against anaerobic bacteria. All tested irrigants were similarly effective against aerobic bacteria. CNPs and CHX/CNPs were associated with significantly lower post-operative pain levels in the first 24 h after treatment. CONCLUSIONS: CNPs and its combination with CHX are significantly more effective than both CHX and NaOCl against anaerobic bacteria isolated from necrotic mandibular premolars. Post-operative pain intensity was significantly lower with CNPs and CNPs/CHX combination than with either NaOCl or CHX.

Contemporary Cleaning of the Root Canal System

This article provides a contemporary synopsis of effective cleaning of the root canal system, an essential stage of root canal treatment. It provides a clinical update on the current state of knowledge on cleaning of the root canal system, and presents an outline of essential theory and practical tips for achieving effective and safe cleaning of the root canal system.

Influence of different irrigation protocols on microhardness and flexural strength values of young and aged crown dentin

OBJECTIVE

To investigate the effect of different irrigation protocols on microhardness (MH) and flexural strength (FS) values of young and aged crown dentin.

BACKGROUND

In addition to ageing, root canal irrigation might also affect the mechanical properties of coronal dentin walls.

MATERIALS AND METHODS

One hundred and twenty dentin bars (2 mm × 2 mm × 8 mm) were obtained from the crowns of extracted, non-caries, human molars of young and older patients (n = 60 bars; average patient ages: 16.7 and 65.4, respectively). Subgroups were formed as follows: 2.5%NaOCl(sodium hypochlorite)+5%EDTA(ethylenediaminetetraacetic acid), 2.5%NaOCl + 15%EDTA, 2.5%NaOCl, 5%EDTA, 15%EDTA and Saline. NaOCl and saline were used for 20 minutes and EDTA solutions for 1 minute. MH values of each sample were measured before and after the irrigation protocols. The same samples were also submitted for FS analysis. The data were statistically analysed.

RESULTS

Young samples had lower MH values at pre- and post-treatment compared to aged samples (P < .05). A significant decrease was observed in MH values of aged samples exposed to 2.5%NaOCl and both NaOCl + EDTA combinations (P < .05). FS values of the young saline-treated group were statistically higher than aged ones (P < .05). Both NaOCl + EDTA combinations caused a significant decrease in FS values of young samples compared to saline (P < .05).

CONCLUSION

Ageing has a significant effect on the MH and FS values of crown dentin samples. 5% EDTA solutions revealed similar results to 15%EDTA regarding MH and FS values of crown dentin in both age groups. The NaOCl + EDTA combination had a prominent effect than EDTA alone, on MH values of young-, and FS values of aged dentin samples.

Nuclear magnetic resonance spectroscopy and infrared spectroscopy analysis of precipitate formed after mixing sodium hypochlorite and QMix 2in1

Background

Mixing sodium hypochlorite (NaOCl) with chlorhexidine (CHX) forms a brown precipitate. QMix-2in1 (QMix) was introduced as a final irrigant. Manufacturer recommends interim flushing with saline between the application of NaOCl and QMix to prevent formation of precipitation. This study assessed whether para-chloroaniline (PCA) is formed after mixing NaOCl with QMix.

Methods

Commercially available, 5.25% NaOCl solution, 2% CHX, QMix, 15% ethylenediaminetetraacetic acid (EDTA) and 98% PCA in powder form were used. Groups were prepared at room temperature. Group 1, 98% PCA in powder form; Group 2, 2% chlorhexidine (CHX); Group 3, QMix; Group 4, 5.25% sodium hypochlorite (NaOCl) mixed with QMix; Group 5, 5.25% NaOCl mixed with CHX; Group 6, 15% EDTA mixed with CHX. The precipitates were extracted and analysed with Proton Nuclear Magnetic Resonance (1H-NMR) and Infrared (IR) Spectroscopy, using PCA as an internal standard.

Results

No PCA was found in any of the irrigant-mixture groups tested.

Conclusions

This study used the interpretation of spectral results for the amino signals of precipitate formed after mixing QMix with 5.25% NaOCl using different nondestructive analysis methods, with PCA as an internal standard (control). We conclude that mixing QMix or 2%CHX with 5.25% NaOCl does not yield free PCA.