Antifungal Activity of Endodontic Irrigants

Introduction: The purpose of this in vitro study was to assess the antifungal activity of final canal rinse with either three concentrations of sodium hypochlorite (NaOCl) (0.5, 2.6 and 6%), two concentrations of chlorhexidine (CHX) (2% and 0.2%), MTAD, Tetraclean, Hypoclean and Chlor-Xtra on Candida albicans (C. albicans) in a human tooth model. Methods and Materials: Two hundred and thirty five extracted human maxillary central and lateral incisors were used in this study. Teeth were randomly divided into nine test groups (n=25) and positive and a negative control groups (n=5). After cleaning and shaping, teeth were contaminated with C. albicans and incubated for 72 h. The irrigation solution in nine experimental groups included: 6% NaOCl, 2.6% NaOCl, 0.5% NaOCl, 2% CHX, 0.2% CHX, MTAD, Tetraclean, Hypoclean and Chlor-Xtra. After culturing on Sabouraud 4% dextrose agar, colony-forming units (CFU) were counted. Results: 6% NaOCl, 2% CHX and Chlor-Xtra were equally effective (P>0.05) and significantly superior to MTAD and Tetraclean (P<0.05). In addition, the effectiveness of Tetraclean and MTAD was significantly less than Hypoclean, NaOCl at all concentrations (6% 2.6% and 0.5%), MTAD and 0.2% CHX (P<0.05). Furthermore, Tetraclean was significantly more effective than MTAD (P<0.05). Conclusion: Antifungal activity of 6% NaOCl, Chlor-Xtra and 2% CHX was significantly greater than 2.6% NaOCl, 0.5% NaOCl, MTAD, 0.2% CHX and Tetraclea

Endodontic Considerations in Three-canalled Premolars: A Practical Update

The most difficult clinical considertions in orthograde root canal treatment are generally related to the anatomy of the teeth. Three-canalled maxillary and mandibular premolars (mini-molars) have been reported in several studies. The purpose of this paper was to review various aspects of three-canalled premolars including incidence, clinical and radiographic diagnosis, racial predisposition, access cavity preparation, instrumentation and obturation.Keywords: Mandibular Premolars; Maxillary Premolars; Mini-Molars; Root Canal Anatomy; Three-Canalled Premolar

Agonistic and Antagonistic Interactions between Chlorhexidine and Other Endodontic Agents: A Critical Review

Root canal irrigants play a significant role in elimination of the microorganisms, tissue remnants, and removal of the debris and smear layer. No single solution is able to fulfill all these actions completely; therefore, a combination of irrigants may be required. The aim of this investigation was to review the agonistic and antagonistic interactions between chlorhexidine (CHX) and other irrigants and medicaments. An English-limited Medline search was performed for articles published from 2002 to 2014. The searched keywords included “chlorhexidine AND sodium hypochlorite/ethylenediaminetetraacetic acid/calcium hydroxide/mineral trioxide aggregate". Subsequently, a hand search was carried out on the references of result articles to find more matching papers. Findings showed that the combination of CHX and sodium hypochlorite (NaOCl) causes color changes and the formation of a neutral and insoluble precipitate; CHX forms a salt with ethylenediaminetetraacetic acid. In addition, it has been demonstrated that the alkalinity of calcium hydroxide (CH) remained unchanged after mixing with CHX. Furthermore, mixing CHX with CH may enhance its antimicrobial activity; mixing mineral trioxide aggregate (MTA) powder with CHX increases its antimicrobial activity but may have a negative effect on its mechanical properties

A Clinical Update on the Different Methods to Decrease the Occurrence of Missed Root Canals

One of the main causes of endodontic treatment failure is the clinician’s inability to localize all the root canals. Due to the complex anatomy of the root canal system, missed canals are not uncommon. There are several strategies to decrease the possibility of missed root canals starting with good pre-operative radiographies. In order to overcome the limitations of conventional radiographies, cone-beam computed tomography (CBCT) can be considered. A correct access cavity preparation is of pivotal importance in localizing the orifices of the root canals. Furthermore, ultrasonics are very important devices to find missed canals. Increasing magnification and illumination enhance the possibility of finding all root canals during root canal treatment. The purpose of the present paper was to review all of the above techniques and devices.Keywords: Access Cavity; Cone-Beam Computed Tomography; Microscope; Missed Canals; Radiography; Root Canal Morphology; Transillumination; Ultrasonic

A Review of the Various Surface Treatments of NiTi Instruments

Since the introduction of engine-driven nickel-titanium (NiTi) instruments, attempts have been made to minimize or eliminate their inherent defects, increase their surface hardness/flexibility and also improve their resistance to cyclic fatigue and cutting efficiency. The various strategies of enhancing instrument surface include ion implantation, thermal nitridation, cryogenic treatment and electropolishing. The purpose of this paper was to review the metallurgy and crystal characteristics of NiTi alloy and to present a general over review of the published articles on surface treatment of NiTi endodontic instruments

A Review of the Properties and Applications of Ozone in Endodontics: An Update

Ozone is a triatomic molecule consisting of three oxygen atoms. It is applied to oral tissues in the forms of ozonated water, ozonated olive oil and oxygen/ozone gas. This paper presents a brief review on the chemistry of ozone as well as its medical and dental applications focusing on its use in endodontics. Ozone’s antimicrobial activity, its effect on dentin bonding, toxicity and contra-indications are also reviewed

The in vitro Effect of Irrigants with Low Surface Tension on Enterococcus faecalis

Introduction: Due to the complex anatomy of the root canal system and high surface tension of common root canal irrigants (RCI), conducting an investigation on RCIs containing surfactants is a priority. The aim of this in vitro study was to verify the antibacterial potential of RCI with low surface tension in root canals infected with Enterococcus faecalis (E. faecalis). Methods and Materials: Thirty-five extracted human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. After root canal preparation, the teeth were randomly divided to one positive and one negative control groups and 5 experimental groups: Hypoclean/Tetraclean NA, Hypoclean, Tetraclean, NaOCl/Tetraclean and NaOCl. Bacterial growth was observed by turbidity of culture medium and then measured using a UV spectrophotometer. Data were analyzed in three time intervals (pre-instrumentation and, 20 min and 72 h after canal preparation) using the ANOVA and post hoc Tukey’s tests. The level of significance was set at 0.05. Results: The results indicated the presence of E. faecalis in all post-irrigation samples irrespective of the RCI. However, the optical densities in both post-irrigation periods showed bacterial reduction and significant differences between groups. Conclusion: RCI with low surface tension showed antibacterial potential in E. faecalis infected roots.Keywords: Enterococcus faecalis; Hypoclean; Sodium Hypochlorite; Tetraclea

Root Canal Irrigants and Dentin Bonding: An Update

The purpose of the review was to assess the effect of root canal irrigants on dentin bonding. A PubMed-based search was conducted on the articles published from 1980 to 2016. A brief overview and reviewing the effect on dentin bonding of common root canal irrigation solutions such as sodium hypochlorite (NaOCl), chlorhexidine (CHX), ethylenediaminetetraacetic acid (EDTA), mixture of a tetracycline, acid and a detergent (MTAD) and ozone was conducted. Findings showed that, depending on the type of dentin bonding, using NaOCl may decrease, increase or not affect the bond strength. In addition, due to its broad-spectrum matrix metalloproteinase-inhibitoryeffect, CHX as well as MTAD can significantly improve the resin-dentin bondstability. However, the effect of ozone therapy on bond strength was controversial.Keywords: Bond Strength; Chlorhexidine; EDTA; MTAD; Ozone; Sodium Hypochlorit

Impact of Ultrasonic Activation on the Effectiveness of Sodium Hypochlorite: A Review

Using ultrasonic devices in endodontics can enhance the antibacterial and tissue dissolving ability of different root canal irrigants such as sodium hypochlorite (NaOCl) which is the most common irrigant with excellent antibacterial and tissue dissolving abilities. However, due to its high surface tension, its penetration into the irregularities of the root canal system is a challenge. The purpose of this paper was to review the different ultrasonic devices, different types of ultrasonic irrigation, the effect(s) of ultrasonic activation on the antibacterial and biofilm-removal abilities of NaOCl as well as the effect of ultrasonic activation on the smear layer removal ability of NaOCl.Keywords: Antibacterial Activity; Biofilm; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Ultrasonic Activatio

Comparison of Antimicrobial Substantivity of Six Root Canal Irrigants against Enterococcus faecalis

Introduction: The antimicrobial substantivity of Mixture of Doxycycline, Citric acid, and Tween 80 (MTAD), Tetraclean, Tetraclean NA, Q-Mix, 2% Chlorhexidine (CHX) and Octenisept was assessed in human root dentine blocks infected with Enterococcus (E.) faecalis. Methods and Materials: A total of 170 dentine tubes were prepared from human maxillary incisors. After crown and apical third removal, cementum was abraded. The remaining center-holed pieces were cut into 4-mm blocks, infected with E. faecalis in Brain Heart Infusion (BHI) broth for 28 days, then randomly divided into 6 experimental groups (n=25) and 2 controls (n=10). At 0, 7, 14, 21 and 28 days, dentine chips were removed from the canals, with sequential round burs with increasing diameters, and collected into freshly prepared BHI broth. After culturing, growing colonies were counted as colony forming units (CFU). Conventional non-parametric tests (Kruskal-Wallis and Mann-Whitney tests) were used to assess intra-group (at different time frames) and inter-group (at each experimental time) differences (P=0.05). Results: Tetraclean yielded the lowest CFU counts (P<0.001) at each observation time. Tetraclean NA and Q-Mix showed better (P<0.001) substantivity than 2% CHX and MTAD (except for Q-Mix versus MTAD at 14 days, P=0.21). Conclusions: In this in vitro study, Tetraclean NA and Q-Mix displayed the best antimicrobial substantivity against E. faecalis after Tetraclean in infected human root dentine. Considering the findings of our study and potential drawbacks of antibiotic-based irrigants, free-antibiotic irrigants may represent viable alternative for final rinse in root canal treatment.Keywords: Antimicrobial Substantivity; Enterococcus faecalis; MTAD; Qmix; Tetraclea