Lipopeptide biosurfactant as a potential root canal irrigation agent: Antimicrobial and anti-biofilm evaluation

OBJECTIVES

Lipopeptide Biosurfactant (LB) is a bacteria derived compound able to reduce surface tension between water and hydrophobic substances and exhibit antimicrobial and anti-biofilm properties. This study aimed to investigate the antimicrobial and anti-biofilm effect of a Lipopeptide Biosurfactant (LB) on Enterococcus faecalis, and its potential use in root canal treatment, either as a standalone irrigation solution or in conjunction with sodium hypochlorite (NaOCl).

METHODS

LB was extracted from Bacillus clausii isolate and the dry extract was diluted in deionized water. The antimicrobial effect of LB against planktonic E. faecalis was evaluated by determining the Minimal Inhibitory Concentration (MIC50). The anti-biofilm effect was evaluated by Minimal Biofilm Inhibitory Concentration (MBIC50) and Minimal Biofilm Eradication Concentration (MBEC50) assays on biofilm grown on dentin specimen surface. To evaluate the effectiveness of LB as a single irrigation solution and as a pre-irrigation prior to NaOCl, live and dead bacterial cells were quantified using Confocal Laser Scanning Microscopy (CLSM), and cell biomass was assessed.

RESULTS

LB exhibited an MIC50 and MBIC50 of 100 ppm, with an MBEC50 of 1000 ppm, resulting in 52.94 % biofilm inhibition and 60.95 % biofilm eradication on dentin specimens. The effectiveness was concentration-dependent, at 500 ppm, LB demonstrated comparable antimicrobial efficacy to 2.5 % NaOCl. Pre-irrigation with LB resulted in lower biofilm biomass compared to NaOCl alone.

CONCLUSION

Pre-irrigation with LB enhanced the antimicrobial effect when followed by NaOCl irrigation. Consequently, LB shows promise as both a standalone root canal irrigation solution and as an adjunct to NaOCl in root canal treatment.

CLINICAL SIGNIFICANCE

The study highlights the potential of Lipopeptide Biosurfactant (LB) as an environmentally friendly irrigation solution for root canal treatment, demonstrating potent antimicrobial and anti-biofilm properties against Enterococcus faecalis. LB exhibits concentration-dependent efficacy comparable to 2.5 % NaOCl and can be used as a standalone irrigation solution or in conjunction with NaOCl.

Photodynamic and nitric oxide therapy-based synergistic antimicrobial nanoplatform: an advanced root canal irrigation system for endodontic bacterial infections

BACKGROUND

The main issues faced during the treatment of apical periodontitis are the management of bacterial infection and the facilitation of the repair of alveolar bone defects to shorten disease duration. Conventional root canal irrigants are limited in their efficacy and are associated with several side effects. This study introduces a synergistic therapy based on nitric oxide (NO) and antimicrobial photodynamic therapy (aPDT) for the treatment of apical periodontitis.

RESULTS

This research developed a multifunctional nanoparticle, CGP, utilizing guanidinylated poly (ethylene glycol)-poly (ε-Caprolactone) polymer as a carrier, internally loaded with the photosensitizer chlorin e6. During root canal irrigation, the guanidino groups on the surface of CGP enabled effective biofilm penetration. These groups undergo oxidation by hydrogen peroxide in the aPDT process, triggering the release of NO without hindering the production of singlet oxygen. The generated NO significantly enhanced the antimicrobial capability and biofilm eradication efficacy of aPDT. Furthermore, CGP not only outperforms conventional aPDT in eradicating biofilms but also effectively promotes the repair of alveolar bone defects post-eradication. Importantly, our findings reveal that CGP exhibits significantly higher biosafety compared to sodium hypochlorite, alongside superior therapeutic efficacy in a rat model of apical periodontitis.

CONCLUSIONS

This study demonstrates that CGP, an effective root irrigation system based on aPDT and NO, has a promising application in root canal therapy.

In vitro efficacy of Er:YAG laser-activated irrigation versus passive ultrasonic irrigation and sonic-powered irrigation for treating multispecies biofilms in artificial grooves and dentinal tubules: an SEM and CLSM study

BACKGROUND

Multispecies biofilms located in the anatomical intricacies of the root canal system remain the greatest challenge in root canal disinfection. The efficacy of Er:YAG laser-activated irrigation techniques for treating multispecies biofilms in these hard-to-reach areas has not been proved. The objective of this laboratory study was to evaluate the effectiveness of two Er:YAG laser-activated irrigation techniques, namely, photon-induced photoacoustic streaming (PIPS) and shock wave-enhanced emission photoacoustic streaming (SWEEPS), in treating multispecies biofilms within apical artificial grooves and dentinal tubules, in comparison with conventional needle irrigation (CNI), passive ultrasonic irrigation (PUI), and sonic-powered irrigation (EDDY). Two types of multispecies root canal biofilm models were established in combination with two assessment methods using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) with the aim to obtain more meaningful results.

METHODS

Ninety extracted human single-rooted premolars were chosen for two multispecies biofilm models. Each tooth was longitudinally split into two halves. In the first model, a deep narrow groove was created in the apical segment of the canal wall. After cultivating a mixed bacterial biofilm for 4 weeks, the split halves were reassembled and subjected to five irrigation techniques: CNI, PUI, EDD, PIPS, and SWEEPS. The residual biofilms inside and outside the groove in Model 1 were analyzed using SEM. For Model 2, the specimens were split longitudinally once more to evaluate the percentage of killed bacteria in the dentinal tubules across different canal sections (apical, middle, and coronal thirds) using CLSM. One-way analysis of variance and post hoc multiple comparisons were used to assess the antibiofilm efficacy of the 5 irrigation techniques.

RESULTS

Robust biofilm growth was observed in all negative controls after 4 weeks. In Model 1, within each group, significantly fewer bacteria remained outside the groove than inside the groove (P < 0.05). SWEEPS, PIPS and EDDY had significantly greater biofilm removal efficacy than CNI and PUI, both from the outside and inside the groove (P < 0.05). Although SWEEPS was more effective than both PIPS and EDDY at removing biofilms inside the groove (P < 0.05), there were no significant differences among these methods outside the groove (P > 0.05). In Model 2, SWEEPS and EDDY exhibited superior bacterial killing efficacy within the dentinal tubules, followed by PIPS, PUI, and CNI (P < 0.05).

CONCLUSION

Er:YAG laser-activated irrigation techniques, along with EDDY, demonstrated significant antibiofilm efficacy in apical artificial grooves and dentinal tubules, areas that are typically challenging to access.

Effect of photon-induced photoacoustic streaming and shock-wave enhanced emission photoacoustic streaming technique on the removal of the smear layer after root canal preparation in curved root canals

Background/purpose

The efficiency of root canal irrigation has an important impact on the prognosis of root canal treatment. Photon-induced photoacoustic streaming (PIPS) and shock wave enhanced emission photoacoustic streaming (SWEEPS) are the special modality of Er: YAG laser, whether can they improve the efficiency of root canal irrigation remains to be studied.

Materials and methods

Fifty human teeth with curved root canals were collected and stored in the thymol solution until used in the study. After traditional endodontic cavities preparation, root canals were prepared to size #35 with a 0.04 taper. The final irrigating techniques were as follows: (I) manual dynamic activation (MDA), (II) ultrasonically activated irrigation (UAI), (III) sonically activated irrigation (SAI), (IV) PIPS, and (V) SWEEPS. Fifty teeth were randomly divided into five groups mentioned above. After root canal preparation, the roots were cleaved longitudinally. The dentine surfaces were photographed from the coronal, middle, and apical third of the root by scanning electron microscopy operated at a low vacuum. Two examiners separately graded each image according to the remained smear layer situations.

Results

PIPS and SWEEPS groups showed fewer smear layers remaining than the others in the middle and the apical third (P < 0.05) of the root canal. In contrast, in the coronal third, five groups showed no significant difference (P > 0.05).

Conclusion

PIPS and SWEEPS showed superior smear layer clearing efficiency than traditional irrigating techniques in curved root canals.

Root canal irrigation system using remotely generated high-power ultrasound

Root canal treatment is performed to remove the bacteria proliferating in the root canals of a tooth. Many conventional root canal irrigation methods use an instrument inserted into the root canals. However, bacteria removal is often incomplete in the apical region of the root canal, and the treatment carries clinical risks, such as instrument fracture and extrusion of irrigation liquid through the canal apex. We here suggest a novel, remotely generated high-intensity ultrasound irrigation system that exhibits better irrigation performance and a reduced clinical risk. Our device employs powerful ultrasonic waves generated by a transducer placed outside a target tooth. The generated ultrasonic waves are guided to travel into the root canals. In the root canals of the target tooth, acoustic cavitation occurs, and vapor bubbles are created. The dynamic motions of vapor bubbles create remarkable cleaning effects. Using root canal models, we tested the cleaning performance of the proposed system and compared it with other conventional irrigation methods. The results revealed that biofilm in the apical region of the root canal models can be removed exclusively using the proposed system, thus demonstrating an improvement in cleaning performance. We also measured pressure at the apex of the root canals of an extracted tooth while operating the proposed system. Our system exhibited a smaller pressure compared to the syringe irrigation method, thus suggesting a reduced risk of apical extrusion of the irrigation liquid. Since the proposed system operates without inserting instruments into the root canal, it can clean multiple root canals in a tooth simultaneously with a single treatment. The proposed device would be a breakthrough in root canal treatment in terms of irrigation performance, clinical safety, and ease of treatment.

Micro-CT evaluation of four final irrigation protocols on hard-tissue debris removal from mesial roots of mandibular molars containing isthmus

OBJECTIVES

To evaluate by means of microcomputed tomography (micro-CT), the efficacy of four final irrigation protocols in the removal of hard-tissue debris (HTD) in mesial roots of mandibular molars containing isthmus.

MATERIALS AND METHODS

Forty standardized mesial roots of extracted mandibular molars presenting isthmus were selected. The root canals were prepared and randomly divided into 4 groups (n = 10): EA, EndoActivator (Dentsply Sirona); EC, Easy Clean (Easy Dental Equipment, Belo Horizonte, Brazil); XPF, XP-Endo Finisher (FKG Dentaire, La Chaus-de Fonds, Switzerland); and PUI, passive ultrasonic irrigation using Irrisafe tip (Satelec Acteon, Merignac, France). Each final irrigation protocol was performed in two cycles (60 s), using, respectively, 2.5% sodium hypochlorite and 17% EDTA. Micro-CT scans were obtained pre-operatory, post-preparation, and post-irrigation. The percentage of HTD reduction was calculated. Data was analyzed statistically (ANOVA and Kruskal-Wallis, significance set at 5%).

RESULTS

The percentage of HTD reduction was greatest for the XPF group (77.92%), followed by EA (62.92%), PUI (47.48%), and EC (32.65%). Statistical differences (p < .05) were found between XPF and EC only. A significant difference (p < .05) was found between XPF and EC in all thirds and between PUI and EC in the middle third.

CONCLUSIONS

XPF, EA, and PUI were similarly effective in HTD reduction. However, none of the evaluated protocols was able to completely remove all the debris.

CLINICAL RELEVANCE

Final irrigation protocols aim to clean the canal complexities that are not addressed by the shaping procedures. Micro-CT allowed to assess the removal of hard-tissue debris in the isthmus and canals of mandibular molars.

The effect of various in-vitro and ex-vivo parameters on irrigant flow and apical pressure using manual syringe needle irrigation: Systematic review

BACKGROUND

Fluid dynamics is a majorly neglected aspect to be studied in root canal irrigation. The fundamental rule to understand mechanics is to observe patterns of flow during the process. Thus, this work is conducted to do a systemic assessment of the in-vitro and ex-vivo based studies to evaluate the effect of various parameters on the irrigant flow and apical pressure on using a manual syringe needle for root canal irrigation.

METHODS

The literature search was conducted through libraries such as PubMed (Medline), CINAHL, Embase, Scopus and other hand literature from Google Scholar, the British medical library etc. The systematic review was reported following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. As they include studies that were in-vitro and ex-vivo based, the risk of bias of the selected articles was assessed using a customized tool based on the previous literature and parameters evaluated in the studies included.

RESULTS

The literature search resulted in 101 items of which 19 records were included in this review. Results reported that multiple factors and parameters were assessed to evaluate the flow and apical pressures on using manual syringe needle irrigation.

CONCLUSIONS

Present systematic review gives insights in-depth about the irrigation dynamics of manual syringe needle irrigation. Besides, it is inconclusive to compile a single factor or a single parameter contributing to the enhanced irrigant flow and least apical pressures.

Efficacy of Different Endodontic Irrigant Activation Techniques on Debris Removal from the Mesial Root Canal System of Mandibular Molars

AIM AND OBJECTIVE

This study was conducted to compare debris removal from the mesial canal system with four different irrigation techniques: sonic activation with EDDY, passive ultrasonic irrigation (PUI), mechanical activation with the XP-endo Finisher (XPF), and manual dynamic irrigation (MDI) with gutta-percha.

MATERIALS AND METHODS

Fifty-six extracted mandibular molars with isthmus in the apical 5 mm in mesial roots were sectioned horizontally at 3 mm and 5 mm from the apex. The sections were reassembled, and the mesial canals were prepared chemomecahanically. Specimens were allocated randomly into four groups according to the final irrigation technique. Standardized images of the coronal aspect of cross sections were obtained using a digital stereomicroscope before and after final irrigation protocols to calculate the percentage of debris elimination from the canal system after final irrigation.

RESULTS

The use of EDDY, PUI, and XPF exhibited significant reductions in debris compared with MDI at 5 mm (p <0.00) and at 3 mm (p <0.00). Furthermore, no significant difference was noted among EDDY, PUI, and XPF. For intragroup analysis, no statistically significant difference in the percentage of debris elimination was noted between 3 mm and 5 mm in all four groups.

CONCLUSION

All groups showed a reduction in debris after the final irrigation protocol. However, the use of EDDY, PUI, and XPF after cleaning and shaping yielded a significant reduction in debris compared with MDI.

CLINICAL SIGNIFICANCE

The use of PUI, XPF, and EDDY as an adjunctive irrigation step presented similar results in improving canal cleanliness, which is hypothesized to affect the treatment outcome.

A Review Over Benefits and Drawbacks of Combining Sodium Hypochlorite with Other Endodontic Materials

Introduction:

As the root canal system considered to be complex and unpredictable, using root canal irrigants and medicaments are essential in order to enhance the disinfection of the canal. Sodium hypochlorite is the most common irrigant in endodontics. Despite its excellent antimicrobial activity and tissue solubility, sodium hypochlorite lacks some important properties such as substantivity and smear layer removing ability.

Objective:

The aim of this review was to address benefits and drawbacks of combining sodium hypochlorite with other root canal irrigants and medicaments.

Discussion:

According to the reviewed articles, NaOCl is the most common irrigation solution in endodontics. However, it has some drawbacks such as inability to remove smear layer. One of the drawbacks of NaOCl is its inability to remove the smear layer and lack of substantivity.

Conclusion:

The adjunctive use of other materials has been suggested to improve NaOCl efficacy. Nevertheless, further studies are required in this field.

Canal cleanliness using different irrigation activation systems: a SEM evaluation

OBJECTIVES

The purpose of this study was to assess the efficacy of different final irrigation activation methods in removing debris and smear layer in the apical, middle, and coronal portion of straight root canals.

MATERIAL AND METHODS

Straight root canals of 58 freshly extracted mandibular premolars were used. Root canals were prepared to size 40.06. Irrigation was performed using 3% sodium hypochlorite. Samples were divided into four equal groups (n = 12) according to the irrigation activation techniques: (A) manual irrigation (MI), (B) EndoActivator (EA) (Dentsply Maillefer, Ballaigues, Switzerland), (C) sonic activation EDDY (EDDY; VDW, Munich, Germany), and (D) passive ultrasonic irrigation (PUI). Ten teeth served as negative controls. Roots were split longitudinally, and the canal walls were subjected to scanning electron microscopy. The presence of debris and smear layer at coronal, middle, and apical levels were evaluated using a 5-point scoring system and statistically analyzed using Kruskal-Wallis and chi-square tests.

RESULTS

Canal cleanliness decreased from coronal to apical (P = 0.035). Significantly more debris was removed with EA, EDDY, and PUI compared to MI (P < 0.001; total values), but no differences were observed in the different portions of the root canals (P > 0.05). Smear layer removal with PUI, EA, and EDDY was not significantly different (P > 0.05), but only EDDY and PUI were superior to MI (P < 0.01).

CONCLUSION

All activation methods created nearly debris-free canal walls and were superior compared to manual irrigation (P < 0.001). EDDY and PUI also showed significantly better smear layer scores compared to manual irrigation.

CLINICAL RELEVANCE

The sonic activation system EDDY performed equally as well as PUI, and both methods were significantly superior compared with manual irrigation in straight root canals with regard to debris and smear layer removal.

Root Canal Irrigation: Chemical Agents and Plant Extracts Against Enterococcus faecalis

BACKGROUND

There are various microorganisms related to intra and extra-radicular infections and many of these are involved in persistent infections. Bacterial elimination from the root canal is achieved by means of the mechanical action of instruments and irrigation as well as the antibacterial effects of the irrigating solutions. Enterococcus faecalis can frequently be isolated from root canals in cases of failed root canal treatments. Antimicrobial agents have often been developed and optimized for their activity against endodontic bacteria. An ideal root canal irrigant should be biocompatible, because of its close contact with the periodontal tissues during endodontic treatment. Sodium hypoclorite (NaOCl) is one of the most widely recommended and used endodontic irrigants but it is highly toxic to periapical tissues.

OBJECTIVES

To analyze the literature on the chemotherapeutic agent and plant extracts studied as root canal irrigants. In particularly, the study is focused on their effect on Enterococcus faecalis.

METHOD

Literature search was performed electronically in PubMed (PubMed Central, MEDLINE) for articles published in English from 1982 to April 2015. The searched keywords were "endodontic irrigants" and "Enterococcus faecalis" and "essential oil" and "plant extracts".

RESULTS

Many of the studied chemotherapeutic agents and plant extracts have shown promising results in vitro.

CONCLUSION

Some of the considered phytotherapic substances, could be a potential alternative to NaOCl for the biomechanical treatment of the endodontic space.

Comparative Evaluation of Antimicrobial Activity of QMiX, 2.5% Sodium Hypochlorite, 2% Chlorhexidine, Guava Leaf Extract and Aloevera Extract Against Enterococcus faecalis and Candida albicans - An in-vitro Study

INTRODUCTION

Debridement and disinfection of the root canal system is a critical step in endodontic treatment. Most of the irrigants presently used in the endodontic treatment can have an impact on the microbes surviving in the biofilm but none of them are able to do all of the required tasks. Researches are going on its full swing in order to produce an endodontic irrigant having ideal properties.

AIM

To compare the antimicrobial efficacy of different irrigants like QMiX, guava leaf extract, aloevera extract, 2.5% sodium hypochlorite and 2% chlorhexidine gluconate against Enterococcus faecalis and Candida albicans.

MATERIALS AND METHODS

The antimicrobial activity was determined using agar diffusion test. The solutions were divided into five groups: Group I- QMiX, Group II- Guava leaf extract and Group III-Aloevera extract, Group IV-2.5% Sodium hypochlorite and Group V-2% Chlorhexidine. The zones of inhibition of growth were recorded.

RESULTS

Statistical analysis was performed using one way ANOVA with post-hoc Tukey's HSD. Values obtained were statistically analyzed (p<0.05). QMiX showed maximum inhibitory effect against Enterococcus faecalis and Candida albicans followed by, 2% chlorhexidine, 2.5% sodium hypochlorite, guava leaf extract and aloevera extract. Results obtained were statistically significant.

CONCLUSION

Guava leaf extract showed significant inhibitory effects against Enterococcus faecalis and Candida albicans. QMiX demonstrated the best results among the tested solutions and can be considered as a potential alternative to existing root canal irrigants.

Influence of lasing parameters on the cleaning efficacy of laser-activated irrigation with pulsed erbium lasers

Laser-activated irrigation (LAI) using erbium lasers is an irrigant agitation technique with great potential for improved cleaning of the root canal system, as shown in many in vitro studies. However, lasing parameters for LAI vary considerably and their influence remains unclear. Therefore, this study sought to investigate the influence of pulse energy, pulse frequency, pulse length, irradiation time and fibre tip shape, position and diameter on the cleaning efficacy of LAI. Transparent resin blocks containing standardized root canals (apical diameter of 0.4 mm, 6% taper, 15 mm long, with a coronal reservoir) were used as the test model. A standardized groove in the apical part of each canal wall was packed with stained dentin debris. The canals were filled with irrigant, which was activated by an erbium: yttrium aluminium garnet (Er:YAG) laser (2940 nm, AT Fidelis, Fotona, Ljubljana, Slovenia). In each experiment, one laser parameter was varied, while the others remained constant. In this way, the influence of pulse energy (10-40 mJ), pulse length (50-1000 μs), frequency (5-30 Hz), irradiation time (5-40 s) and fibre tip shape (flat or conical), position (pulp chamber, canal entrance, next to groove) and diameter (300-600 μm) was determined by treating 20 canals per parameter. The amount of debris remaining in the groove after each LAI procedure was scored and compared among the different treatments. The parameters significantly (P < 0.05, Kruskal-Wallis) affecting debris removal from the groove were fibre tip position, pulse length, pulse energy, irradiation time and frequency. Fibre tip shape and diameter had no significant influence on the cleaning efficacy.

Adverse Reaction of Sodium Hypochlorite during Endodontic Treatment of Primary Teeth

Sodium hypochlorite (NaOCl) is the most common and effective intracanal medicament used in root canal treatments, because of its low-cost and a very effective antimicrobial activity against microbiota of infected root canals. Sodium hypochlorite is an effective intracanal irrigant and is used in concentrations ranging from 0.5 to 5.25%. At these concentrations, it is highly hypertonic and strongly alkaline with pH 11 to 13. Despite its safe properties, serious complications can result from inadvertent use due to its cytotoxic features. Most of the complications are the result of accidental extrusion of the solution from the apical foramen or accessory canals or perforations into the periapical area. Although it is an effective solution for disinfection of root canal system, fewer incidence of complications are reported, especially in primary teeth. Present article highlights one of such cases of NaOCl accident and its successful management in a 4-year-old child.

How to cite this article: Chaugule VB, Panse AM, Gawali PN. Adverse Reaction of Sodium Hypochlorite during Endo-dontic Treatment of Primary Teeth. Int J Clin Pediatr Dent 2015;8(2):153-156.