An in vitro evaluation of various irrigation techniques for the removal of double antibiotic paste from root canal surfaces

Effect of Vehicles and Irrigation Solutions and Methods on Removal of Double Antibiotic Paste from Root Canals: Insights from High-performance Liquid Chromatography Analysis

INTRODUCTION

In regenerative endodontics, eradicating antibiotic residues from root canals is imperative, given their detrimental effects on human apical papilla stem cells. Previous antibiotic removal studies lacked precision in identifying types and quantities of residual antibiotics. High-performance liquid chromatography (HPLC) enhances sensitivity and specificity, enabling accurate detection and quantification of residual drugs. Using HPLC analysis, this study explored the influence of vehicles and irrigation solutions and methods on double antibiotic paste (DAP) removal from root canals.

METHODS

Two DAP formulations, each containing 5 mg/mL ciprofloxacin and metronidazole, were created using distinct vehicles: macrogol and propylene glycol (MP) or hydroxypropyl methylcellulose (HPMC). Subsequently, 5 μL of DAP was applied to 200 simulated immature teeth with open apices (n = 100 per formulation) and cultured for 28 days at 37°C. Samples were then divided into 11 groups (n = 20 per group), and canals were irrigated with 17% ethylenediaminetetraacetic acid or 10% citric acid, employing a positive pressure syringe or passive ultrasonic irrigation. The irrigation solution and dentin sample from each tooth were evaluated via HPLC for ciprofloxacin and metronidazole quantification.

RESULTS

Citric acid exhibited significantly superior efficacy in antibiotic removal from root canals, with no observable effect of irrigation methods on drug removal. The HPMC-based DAP formulation significantly enhanced ciprofloxacin removal compared with MP-based DAP.

CONCLUSIONS

For antibiotic paste removal from root canals, citric acid is effective, and HPMC is a preferable vehicle over MP. Overall, HPLC is a valuable method for detecting, removing, and quantifying residual antibiotics in root canals.

The efficacy of various irrigation techniques on the removal of double antibiotic paste from simulated immature roots and the amount of apically extruded debris

OBJECTIVE

This study evaluated the effect of the XP-Endo Finisher (XPF), passive ultrasonic irrigation (PUI) and conventional irrigation using side-vented needle (SVN) on the amount of apically extruded debris and canal cleanliness following the removal of double antibiotic paste (DAP) from immature root canal models.

MATERIAL AND METHODS

Forty-eight extracted mandibular premolars were drilled using peeso drills to simulate immature apices. The canals were filled with DAP and were randomly assigned into 3 groups according to the DAP removal method: XPF, PUI, and SVN (n = 16). The amount of extruded debris was assessed with an analytical balance then roots were split longitudinally and imaged using stereomicroscope to evaluate the residual medicament. Data were statistically analyzed using Kruskal-Wallis and Dunn's test. Spearman's correlation coefficient was used to determine significant correlation between extruded debris and the residual DAP scores.

RESULTS

There was no significant difference between debris extrusion values for all groups (P value 0.237). For canal cleanliness, the amount of remaining DAP was significantly lower in the XPF and PUI compared to SVN (P value < 0.001). A non-significant positive (direct) correlation was found between the amounts of apically extruded debris and residual DAP scores (P value 0.087).

CONCLUSION

XPF and PUI were associated with better canal cleanliness during removal of DAP, no difference could be found between the three irrigation techniques regarding the debris extrusion.

The antimicrobial efficacy of nanographene oxide and double antibiotic paste per se and in combination: part II

BACKGROUND

Finding strategies to overcome the rising trends of antimicrobial resistance against currently available antimicrobial agents has become increasingly relevant. Graphene oxide has recently emerged as a promising material due to its outstanding physicochemical and biological properties. This study aimed to validate previous data on the antibacterial activity of nanographene oxide (nGO), double antibiotic paste (DAP), and their combination (nGO-DAP).

METHODS

The antibacterial evaluation was performed against a wide range of microbial pathogens. Synthesis of nGO was achieved using a modified Hummers' method, and loading it with ciprofloxacin and metronidazole resulted in nGO-DAP. The microdilution method was utilized to assess the antimicrobial efficacy of nGO, DAP, and nGO-DAP against two gram-positive bacteria (S. aureus and E. faecalis), two gram-negative bacteria (E. coli, and S. typhi), and an opportunistic pathogenic yeast (C. albicans). Statistical analysis was conducted using one-sample t-test and one-way ANOVA (α = 0.05).

RESULTS

All three antimicrobial agents significantly increased the killing percent of microbial pathogens compared to the control group (P < 0.05). Furthermore, the synthesized nGO-DAP exhibited higher antimicrobial activity than nGO and DAP per se.

CONCLUSION

The novel synthesized nGO-DAP can be used as an effective antimicrobial nanomaterial for use in dental, biomedical, and pharmaceutical fields against a range of microbial pathogens, including gram-negative and gram-positive bacteria, as well as yeasts.

Engineering of Injectable Antibiotic-laden Fibrous Microparticles Gelatin Methacryloyl Hydrogel for Endodontic Infection Ablation

This study aimed at engineering cytocompatible and injectable antibiotic-laden fibrous microparticles gelatin methacryloyl (GelMA) hydrogels for endodontic infection ablation. Clindamycin (CLIN) or metronidazole (MET) was added to a polymer solution and electrospun into fibrous mats, which were processed via cryomilling to obtain CLIN- or MET-laden fibrous microparticles. Then, GelMA was modified with CLIN- or MET-laden microparticles or by using equal amounts of each set of fibrous microparticles. Morphological characterization of electrospun fibers and cryomilled particles was performed via scanning electron microscopy (SEM). The experimental hydrogels were further examined for swelling, degradation, and toxicity to dental stem cells, as well as antimicrobial action against endodontic pathogens (agar diffusion) and biofilm inhibition, evaluated both quantitatively (CFU/mL) and qualitatively via confocal laser scanning microscopy (CLSM) and SEM. Data were analyzed using ANOVA and Tukey's test (α = 0.05). The modification of GelMA with antibiotic-laden fibrous microparticles increased the hydrogel swelling ratio and degradation rate. Cell viability was slightly reduced, although without any significant toxicity (cell viability > 50%). All hydrogels containing antibiotic-laden fibrous microparticles displayed antibiofilm effects, with the dentin substrate showing nearly complete elimination of viable bacteria. Altogether, our findings suggest that the engineered injectable antibiotic-laden fibrous microparticles hydrogels hold clinical prospects for endodontic infection ablation.

Effectiveness of XP-Endo Finisher and passive ultrasonic irrigation on intracanal medicament removal from root canals: a systematic review and meta-analysis

Background

XP-Endo Finisher (XPF) and passive ultrasonic irrigation (PUI) are commonly used in intracanal medicament removal. The effectiveness of these two techniques needs to be compared, and evidence-based research should be conducted.

Methods

A comprehensive literature search was conducted in PubMed, Web of Science, Embase, Cochrane Library, and Google Scholar up to December 20th, 2020. The outcomes of the included trials were pooled into the Cochrane Collaboration’s Review Manager 5.3 software. Cochrane’s risk-of-bias tool 2.0 was applied to assess the risk of bias.

Results

Nine articles were included in this systematic review and processed for data extraction, and eight studies were identified for meta-analysis. In general, the use of PUI showed better medicament removal effectiveness than XPF (odds ratio [OR]: 3.09; 95% confidence interval [CI], 1.96–4.86; P < 0.001). PUI was also significantly more efficient than XPF in the apical third (OR: 3.42; 95% CI, 1.32–8.84; P = 0.01). For trials using sodium hypochlorite (NaOCl) alone, PUI was also significantly more effective than XPF on intracanal medicaments removal (OR: 5.23; 95% CI, 2.79–9.82; P < 0.001). However, there was no significant difference between PUI and XPF when NaOCl and ethylenediaminetetraacetic acid (EDTA) were used in combination (OR: 1.51; 95% CI, 0.74–3.09; P = 0.26). In addition, for studies whose intracanal medicament periods were two weeks, the effectiveness of PUI was statistically better than the XPF (OR: 7.73; 95% CI, 3.71–16.07; P < 0.001). Nevertheless, for trials whose intracanal medicament time was one week or over two weeks, no differences between the XPF and PUI were found (OR: 1.54; 95% CI, 0.74–3.22; P = 0.25) (OR: 1.42; 95% CI, 0.44–4.61; P = 0.56).

Conclusions

The meta-analysis is the first study to quantitatively compare the effectiveness of XPF and PUI techniques on intracanal medicaments removal. With rigorous eligibility criteria, the study only included high-quality randomised controlled trials. The study indicated that PUI might be superior over XPF techniques for removing intracanal medicaments from artificial standardized grooves and cavities in the root canal system. The anatomical areas, irrigation protocol, and intracanal medicaments time may influence the cleaning efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01644-7.

The Comparative Toxicity of Xanthones and Tannins in Mangosteen (Garcinia mangostana Linn.) Pericarp Extract against BHK-21 Fibroblast Cell Culture

Objective:

The objective of this study is to compare the toxicity level of xanthones and tannins derived from mangosteen pericarp extract at specific concentrations against BHK-21 fibroblast cell cultures.

Methods:

Mangosteen was extracted using a maceration method with ethanol 96%. Xanthones were isolated from the chloroform extract, whereas tannins were isolated using acetone alcohol and serial diluted to 100% concentration. Toxicity levels were monitored after 24 h using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay technique by ELISA reader at 620 nm.

Results:

Viable cells of BHK-21 against xanthone concentration began to decrease (40.24%) at 3.98% xanthones, whereas viable cells of BHK-21 against tannin concentration began to decrease (68.06%) at 2.2% tannins.

Conclusion:

It is suggested that tannins were more toxic than the xanthones derived from mangosteen pericarp.

Cleaning Efficacy of the XP-Endo® Finisher Instrument Compared to Other Irrigation Activation Procedures: A Systematic Review

Background. One of the most important aims of an endodontic treatment is to obtain the complete removal or reduction of root canal remaining filling material: Smear layer, bacteria, intra-canal medicaments. To meet this requirement, several irrigation activation techniques have been proposed. Our systematic review examined studies which analyzed the XP-endo Finisher (XPF) instrument efficacy in removing root canal debris during initial endodontic treatment or retreatment, comparing it with the efficacy of other irrigation activation protocols, such as passive ultrasonic irrigation (PUI), laser activation procedure (Er:YAG), and Self-Adjusting File system (SAF). Methods. A systematic review was conducted using PubMed, Chocrane Library, and Scopus databases, identifying 51 items. Thirty-four articles were excluded based on title, abstract, full text, and language. Seventeen randomized controlled trials were selected and consequently submitted to quality assessment and data collection. Results. Conventional needle irrigation (CNI) is the less effective irrigation technique, but it is still unclear whether XPF is able to guarantee greater debris removal than the PUI technique. Er:YAG laser has been proven to be more effective in apical third than XPF instrument. Conclusions. Further investigations are needed in order to establish which final irrigation activation procedure could reach the maximum root canal debris reduction.

Effect of Intracanal Medicaments on Pull-Out Bond Strength of Fiber Post Cemented with a Self-Adhesive System

OBJECTIVES

 This study aimed to assess the effect of four intracanal medicaments on pull-out bond strength of fiber posts.

MATERIALS AND METHODS

 A total of 65 single-rooted, single-canal teeth were selected and decoronated. Root canals were prepared and after rinsing were randomly divided into five groups (n = 13). G₁: calcium hydroxide (CH), G_2: CH plus chlorhexidine (CH+CHX), G₃: triple antibiotic paste (TAP), G₄: double antibiotic paste (DAP) were applied in the canals in the four groups. The control group (G₅) received no medicament. After 4 weeks, the medicaments were rinsed off and the canals were filled with gutta-percha. Post space was then prepared in root canals for the placement of glass fiber posts and self-adhesive cement (Panavia F2). After cementation, they were subjected to pull-out bond strength test.

STATISTICAL ANALYSIS

 Data were statistically analyzed using one-way analysis of variance and Tukey test.Results The pull-out bond strength values were significantly different in the groups (p < 0.001). The highest values of bond strength were seen in G₂, G₁, and G₃ (359.97 ± 81.26, 333.79 ± 98.96, 309.27 ± 78.07), respectively. There was no significant difference between G₄ and G₅ (p = 0.75).

CONCLUSION

 The results showed that CH, CH+CHX, and TAP enhanced the pull-out bond strength of fiber post to root canal wall as compared to the control group.

Effect of intracanal time of triple antibiotic paste on its removal from simulated immature roots using passive ultrasonic irrigation and XP-endo Finisher

Background. The aim of this study was to evaluate the effectiveness of different irrigation techniques in the removal of triple antibiotic paste (TAP), which was applied for 7, 21 or 90 days, from simulated root canals of immature teeth.

Methods. The root canal spaces of 190 maxillary canine teeth were filled with TAP and randomly divided into a control and 3 experimental groups according to the intracanal medicament period (7, 21 or 90 days). Syringe irrigation (SI), passive ultrasonic irrigation (PUI) and XP-endo Finisher (XP) were used for the removal of TAP (n=20). The amount of remaining medicament was calculated under a stereomicroscope using a 4-grade scoring system. Kruskal-Wallis H and Wilcoxon signedrank tests were used for statistical analyses (P<0.05).

Results. The mean percentage of residual TAP was significantly greater in the SI group compared to PUI and XP at all the time intervals (P<0.05). Paste removal efficacy of PUI was not affected by the intracanal time of TAP (P>0.05), whereas the efficacy of SI and XP was significantly affected (P<0.05). No significant differences were detected between PUI and XP at 7- and 21-day intervals (P>0.05); however, at 90-day interval, PUI removed significantly greater amount of TAP than XP did (P<0.05).

Conclusion. The time of the TAP in the root canal negatively affected the removal efficacy of the SI and XP-Endo Finisher; however, it did not affect the efficacy of the PUI.