Cleaning effectiveness of root canal irrigation with electrochemically activated anolyte and catholyte solutions: a pilot study

Electrolysed oxidising water as a multi-purpose biocide in dental healthcare-A scoping review

OBJECTIVES

The objective of this scoping review was to map evidence of electrolysed oxidising water (EOW) as a biocide for dental applications of relevance to older people and identify research gaps.

BACKGROUND

EOW is an emerging, "green," and cost-effective biocide. There are no reviews on the landscape of EOW research as either an antiseptic or disinfectant in dental healthcare or its suitability for the oral healthcare of older people.

MATERIALS AND METHODS

The review follows the PRISMA Extension for Scoping Reviews (PRISMA-ScR) guidelines. Database searches (Google Scholar, PubMed, Web of Science, Ovid, Scopus and Science Direct) were undertaken using MESH terms and Boolean operators with no date restrictions, to identify full-text, original reports published in English-language peer-reviewed journals.

RESULTS

The search yielded 114 papers that met the inclusion/exclusion criteria. Dental applications of EOW include its use as an endodontic irrigant (39%); mouth rinse/surgical irrigant (21%); disinfectant for dental unit water lines (19%) and dental biomaterials (17%); and for antimicrobial efficacy, effects on oral tissues and on dental material properties. Most studies (83%) evaluated a single EOW formulation (acidic, moderately acidic or neutral) that was either generated at 'point-of-use' (POU; 72%), bottled ('ready-to-use', RTU; 24%) or from unspecified (3%) sources. Six reports evaluated storage-related parameters and 25 evaluated clinical applications; 89 were in vitro studies and one investigated the cost-effectiveness of POU EOW.

CONCLUSIONS

Neutral-pH, EOW is effective as an antimicrobial agent without deleterious effects on oral tissues. However, research on the impact of storage conditions, anti-Candida biofilm efficacy and mechanism of action against yeasts, long-term effects on denture materials and cost-effectiveness is required to establish the suitability of EOW as a multipurpose biocide for dental healthcare, including infection-control requirements relating to older people.

Recent Update on Applications of Quaternary Ammonium Silane as an Antibacterial Biomaterial: A Novel Drug Delivery Approach in Dentistry

Quaternary ammonium silane [(QAS), codename – k21] is a novel biomaterial developed by sol-gel process having broad spectrum antimicrobial activities with low cytotoxicity. It has been used in various concentrations with maximum antimicrobial efficacy and biocompatibility. The antimicrobial mechanism is displayed via contact killing, causing conformational changes within the bacterial cell membrane, inhibiting Sortase-A enzyme, and causing cell disturbances due to osmotic changes. The compound can attach to S1' pockets on matrix metalloproteinases (MMPs), leading to massive MMP enzyme inhibition, making it one of the most potent protease inhibitors. Quaternary ammonium silane has been synthesized and used in dentistry to eliminate the biofilm from dental tissues. QAS has been tested for its antibacterial activity as a cavity disinfectant, endodontic irrigant, restorative and root canal medication, and a nanocarrier for drug delivery approaches. The review is first of its kind that aims to discuss applications of QAS as a novel antibacterial biomaterial for dental applications along with discussions on its cytotoxic effects and future prospects in dentistry.

Current Trends in Root Canal Irrigation

Chemical and mechanical root canal debridement are the primary methods used in endodontic therapy to remove all dead tissue, bacteria, and microbial byproducts from the canal. Sodium hypochlorite, a powerful organic tissue dissolver with a broad spectrum of antibacterial properties, is an excellent choice for disinfecting surfaces. Chelating agents, on the other hand, may be used to remove the inorganic components found on the smear layer. This irrigation method is capable of removing the smear layer; however, it is less effective in the apical third. While using irrigant activation devices, irrigating solutions need to be in direct contact with the whole root canal wall surfaces, especially in the apical portions of tiny root canals. The role of irrigants is extremely important because they help not only to clean the canal but also to allow the seepage of the medicaments into the canal system. Thus, the canal needs to be healthy before the obturation procedure. Nowadays, many irrigants have been studied and hence compilation of the various available sources and their effect has to be studied both in vivo and in vitro. The correlation between the irrigants and the canal cleanliness is of utmost importance, as the success of endodontic root canal treatment depends on its proper activation and characteristics. Hence, this review incorporates the current use of various irrigating solutions and their advantages and disadvantages. In the future, endodontists may employ the novel irrigants and irrigant activation devices that were discovered in this study.

In vitro antimicrobial activity of different electrochemically-activated solutions on enterococcus faecalis

Purpose

The aim of this in vitro study was to assess and compare the antimicrobial efficacy of different electrochemically-activated solutions (ECA) and contemporary irrigants, in root canals infected with Enterococcus faecalis, used with or without EndoActivator (EA).

Materials and methods

A hundred single-rooted human teeth were prepared. Ninety of the root segments were infected with E. faecalis for four weeks, and divided into eight test groups (n = 10) (four with and four without EA sonication) and a positive control (n = 10). The irrigants tested were electrochemically-activated solutions produced by the Medilox® (ECA-MX) and Envirolyte® devices (ECA-EN), 2% CHX and 2.5% NaOCl. The root specimens were irrigated with 5 mL of the test solution, with additional sonic agitation applied to the EA groups. The dentine samples that were obtained from the walls were cultured, and the antibacterial efficacy was evaluated by counting the colony-forming units.

Results

The ECA-EN, 2.5% NaOCl and 2% CHX were more effective than the ECA-MX (p<0.05) with the addition of EA sonication, showing no statistical difference in the elimination of E. faecalis.

Conclusion

The ECA-EN shows potential as an endodontic irrigant, while EA usage gives no benefit in reducing bacteria from root canals.

Electrolyzed saline… an alternative to sodium hypochlorite for root canal irrigation

Objectives

The aim of this study is to evaluate electrolyzed saline, produced from a custom-made chair side apparatus for its cleaning effect on root canal walls.

Methods

A chair side apparatus has been designed to produce and dispense electrolytically activated solutions (Electrolyzed saline) for the purpose of root canal irrigation. Two different solutions, one, which is oxidizing in nature, consisting primarily of Chlorine derivatives and another, reducing in nature, consisting primarily of sodium hydroxide, are obtained. A combination of these two solutions was used for root canal irrigation in extracted teeth. Root canals were split and the samples were subjected to Scanning electron microscopic evaluation.

Results

Under the conditions of this study, electrolyzed saline significantly cleaned the root canal surfaces well, opening the dentinal tubules and removing the smear layer.

Significance

There has been a constant search for the ideal root canal irrigant. Sodium hypochlorite has been vastly used but its toxicity and storage risks are of concern. Electrolyzed saline has been produced from saline and the apparatus prepares and dispenses the solution chair side, obviating storage needs.

Activation of Alkaline Irrigation Fluids in Endodontics

In conventional endodontic treatment, alkaline solutions of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) are used in combination to disinfect the root canal system and to eliminate debris and smear layers. An important concept that has emerged over recent years is the use of active physical methods for agitating these fluids to improve their penetration within areas that are not reached by endodontic instruments and to accelerate the chemical actions of these alkaline fluids against planktonic microorganisms, biofilms, soft tissue remnants and smear layers. Ultrasonic agitation and more recently pulsed lasers have emerged as two promising methods for activating endodontic irrigation fluids. Ultrasonic agitation with piezoelectric devices employs a moving tip, while laser agitation uses a stationary tip. Both methods cause cavitation, followed by implosions and shear forces which assist with debridement. Fluid streaming further enhances the activity of the fluids. While agitation enhances performance of irrigants, extrusion of fluids from the root canal during activation is a hazard that must be controlled.

Unusual Root Canal Irrigation Solutions

Microorganisms and their by-products play a critical role in pulp and periradicular pathosis. Therefore, one of the main purposes of root canal treatment is disinfection of the entire system of the canal. This aim may be obtained using mechanical preparation, chemical irrigation, and temporary medication of the canal. For this purpose, various irrigation solutions have been advocated. Common root canal irrigants, such as sodium hypochlorite, chlorhexidine, and a mixture of tetracycline, acid, and detergent have been extensively reviewed. The aim of this review was to address the less common newer root canal irrigation solutions, such as citric acid, maleic acid, electrochemically activated water, green tea, ozonated water, and SmearClear.

Antibacterial Efficacy of Super-Oxidized Water on Enterococcus faecalis Biofilms in Root Canal

Background

The success of endodontic treatment depends on a few crucial factors. One of these factors is the complete chemomechanic preparation of root canal against various bacteria. In particular, the effect of resistant bacteria may cause intense pain with flare-up and formation of periapical lesions. Therefore, the strong effect of irrigants plays an important role in terms of the complete elimination of these bacteria to achieve long-term successful treatment.

Objectives

The aim of this study was to investigate the antibacterial effects of super-oxidized water (SPO) in root canals infected with Enterococcus faecalis biofilms.

Methods

One hundred twenty single-root, premolar teeth were selected. Initially, the teeth were prepared and then disinfected. E. faecalis were inoculated and kept at 37°C for 24 hours in the root canals. The re-inoculation procedure was repeated on the first, fourth, seventh, and tenth days. The infected root canals were divided into one negative (saline) and one positive (sodium hypochlorite) control group and four experimental groups (super-oxidized water: 1, 2, 3, or 5 minutes) (n = 20). Paper points were placed in the root canals to control and evaluate the biofilm formation. Biofilms were counted on blood agar plates, and data was evaluated and statistically analyzed using one-way ANOVA and Tukey’s test.

Results

Although sodium hypochlorite (NaOCl) showed no statistically significant difference when compared with three and five minutes of SPO irrigation (P > 0.05), NaOCl showed statistically significant differences among all other groups (P < 0.05).

Conclusions

Super-oxidized water indicated a remarkable and similar bactericidal effect to that of traditional NaOCl against E. faecalis biofilms. In terms of successful endodontic treatment approaches, super-oxidized water may be used as an effective irrigation solution in clinics.

Anti bacterial Effectiveness of Electro- Chemically Activated (ECA) Water as a Root Canal Irrigant- An In-vitro Comparative Study

INTRODUCTION

Sodium hypochlorite, is the irrigant of choice for many clinicians, but its strong toxic and damaging effects on vital periapical tissues is always a matter of concern. So, the search for a root canal irrigant with a broad antimicrobial spectrum yet with a limited toxicity on vital tissues is always desirable.

AIM

The study evaluated antimicrobial efficacy of Electro-Chemically Activated (ECA) water as a root canal irrigant against E. faecalis.

MATERIALS AND METHODS

Forty eight single rooted human teeth were decoronated to a length of 15mm. All teeth were divided into four test groups (group A - ECA anolyte, group B - 1% sodium hypochlorite, group C - 3% sodium hypochlorite, group D - distilled water) of 12 each. Only 1ml of Ringer's solution and calibrated suspensio of E. faecalis was injected into each canal, aspirated and placed on agar plates and incubated aerobically at 37°C for two days. The suspension was aspirated and spread onto the blood agar plate and incubated. All samples were irrigated with four test solutions and Brain Heart Infusion (BHI) solution was injected into each canal then aspirated and spread onto blood agar and incubated. After inoculations Colony Forming Unit (CFU) and optical density was measured under a microscope and spectrophotometer. The data obtained were statistically analysed by one way ANOVA and Dunkan's multiple range test.

RESULTS

CFU reduction was not statistically significant between the test groups. The optical density showed statistically significant difference between the test groups (p≤0.001).

CONCLUSION

The antimicrobial efficacy of ECA was found to be comparable to sodium hypochlorite solutions.

The effect of micro-electric current and other activation techniques on dissolution abilities of sodium hypochlorite in bovine tissues

Background

The aim of the study was to evaluate the effects of micro-electric current on sodium hypochlorite’s (NaOCl’s) tissue-dissolution abilities, compared with other activation methods, including sonic, ultrasonic, pipetting, and temperature.

Methods

Bovine muscle tissues (n = 154) with standard sizes and weights were prepared and divided into two temperature groups: room temperature and 45 °C. Each temperature group was divided into seven sub-groups by activation methods: D = distilled water (−control); NaOCl = 5.25 % passive NaOCl (+ control); P = 5.25 % NaOCl with pipetting; SA = 5.25 % NaOCl with sonic activation; UA = 5.25 % NaOCl with ultrasonic activation; E-NaOCl = 5.25 % NaOCl with micro-electric current; and E-NaOCl + P = 5.25 % NaOCl with micro-electric current and pipetting. Specimens were weighed before and after treatment. Average, standard deviation, minimum, maximum, and median were calculated for each group. Resulting data were analyzed statistically using multi-way ANOVA and Tukey HSD tests. The level of the alpha-type error was set at < 0.05.

Results

At room temperature, the E-NaOCl + P group dissolved the highest amount of tissue (p < 0.05), and the UA, SA, and P groups dissolved significantly higher amounts of tissue than did the positive control or E-NaOCl groups (p < 0.05). At 45 °C, there was no significant difference between the SA and E-NaOCl groups (p > 0.05), and the E-NaOCl + P group dissolved a higher amount of tissue than any other group (p < 0.05).

Conclusions

Using NaOCl with micro-electric current can improve the tissue-dissolving ability of the solution. In addition, this method can be combined with additional techniques, such as heating and/or pipetting, to achieve a synergistic effect of NaOCl on tissue dissolution.

Effect of Different Irrigating Solutions and Photo-Activated Therapy for In Vivo Root Canal Treatment

This study aimed to evaluate histologically the effect of irrigation with 400 ppm Sterilox, 2% and 5% sodium hypochlorite (NaOCl), with and without photo-activated therapy (PAD), in a single-visit root canal treatment of dog's teeth with apical periodontitis (AP). Ten dogs were randomly divided into two groups (n=5): with and without PAD, and the root canals into four subgroups, according to the irrigating solution: SX (400 ppm Sterilox), SH2 (2% NaOCl), SH5 (5% NaOCl) and SS (saline solution) as positive control. A total of 134 root canals were opened and left exposed to the oral environment for 14 days and then sealed for 60 days for AP induction. Then, root canals were treated according to each proposed disinfecting protocol and filled in the same session. After 120 days, the dogs were euthanized and the periapical inflammatory events were evaluated under light microscopy. Qualitative data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05). PAD did not produce significant differences in the scores for apical inflammation when used after chemo-mechanical preparation (p>0.05). The irrigating solutions SX, SH2 and SH5 without PAD were statistically different from SS (p<0.05) that presented the greatest scores for apical inflammation. PAD did not show any additional effect for the treatment of root canals with pulp necrosis and AP in a single visit and 400 ppm Sterilox may be considered an alternative to NaOCl in root canal treatment.

Bactericidal effects of various irrigation solutions against staphylococcus aureus in human root canal

Purpose:

The aim of the present study was to evaluate and to compare the antibacterial effects of various irrigation solutions against Staphylococcus aureus (S. aureus) in human root canals.

Materials and Methods:

120 single-root mandibular premolar teeth were selected. The teeth were prepared and sterilized. S. aureus was incubated in the root canals and kept at 37°C for 24h. The infected root canals were divided into one positive (saline) and one negative (sodium hypochlorite) control, and four experimental groups [Ethylene-diaminetetra-aceticacid, Chlorhexidine Gluconate, Super-oxidized water(SPO), Aqueous ozone] (n=20). Flow rate of irrigation was applied with 5 mL/min flow rate for 3 min to ensure standardization among all study groups. Following the irrigation, paper points were placed in the root canals and then transferred in sterile eppendorf. Remaining bacteria were counted on blood agar plates and the data were analyzed using one-way ANOVA and Tukey’s test.

Results:

Although there were statistically significant differences among SPO and other experimental groups (p<0.05), there was no statistically significant difference between SPO and NaOCl (p>0.05).

Conclusion:

Super-oxidized water may be recommended as an alternative irrigation solution instead of NaOCl against S. aureus in root canals.

Rapid tissue dissolution efficiency of electrically-activated sodium hypochlorite on bovine muscle

Objective:

Sodium hypochlorite (NaOCl) is a common antimicrobial and tissue-dissolving irrigant. The aim of this in vitro study is to evaluate and compare dissolution capacities of sodium hypochlorite solutions after electrically activation (E-NaOCl) on bovine muscle specimens at various time periods and concentrations.

Materials and Methods:

Three sodium hypochlorite solutions of 1.25%, 2.5%, and 5% were tested at 3-min. and 5-min. with and without activation by electrically. Distilled water and NaOCl solutions without electrically activation were used as controls. Pieces of bovine muscle tissue (34 ± 2 mg) were placed in 10 mL of each solution at room temperature. In the group of E-NaOCl, electrically activation was performed through the potentiostat. The tissue specimens were weighed before and after treatment, and the percentage of weight loss was calculated.

Results:

Weight loss of the tissue increased with the concentration of E-NaOCl and NaOCl. Higher concentration and electrically activation considerably enhanced the efficacy of sodium hypochlorite. The effect of electrically activation on tissue dissolution was much greater than that of same concentrations in the groups of NaOCl (P < 0.001). Tissue weight loss was significantly higher in 2.5% and 5% E-NaOCl at 3 min. than in 2.5% and 5% NaOCl at 5 min. (P < 0.05). There were not any significant differences between the 2.5% E-NaOCl and 5% NaOCl at 5 min. (P > 0.05).

Conclusion:

Electrically activation can improve the tissue-dissolving effectiveness of sodium hypochlorite.

Newer root canal irrigants in horizon: a review

Sodium hypochloride is the most commonly used endodontic irrigant, despite limitations. None of the presently available root canal irrigants satisfy the requirements of ideal root canal irrigant. Newer root canal irrigants are studied for potential replacement of sodium hypochloride. This article reviews the potential irrigants with their advantages and limitations with their future in endodontic irrigation.

Evaluation of the antimicrobial effect of super-oxidized water (Sterilox®) and sodium hypochlorite against Enterococcus faecalis in a bovine root canal model

Ideally root canal irrigants should have, amongst other properties, antimicrobial action associated with a lack of toxicity against periapical tissues. Sodium hypochlorite (NaOCl) is a widely used root canal irrigant, however it has been shown to have a cytotoxic effect on vital tissue and therefore it is prudent to investigate alternative irrigants. Sterilox's Aquatine Alpha Electrolyte^® belongs to the group of the super-oxidized waters; it consists of a mixture of oxidizing substances, and has been suggested to be used as root canal irrigant. Super-oxidized waters have been shown to provide efficient cleaning of root canal walls, and have been proposed to be used for the disinfection of medical equipment.

Some factors influencing the stability of Sterilox(®), a super-oxidised water

Super-oxidised waters, particularly Sterilox(®), have been suggested for the disinfection of dental unit water lines and dental impression materials owing to their antimicrobial efficacy. One of the previously suggested characteristics is their short shelf life. The purpose of this investigation was to understand the effect of storage conditions on Sterilox(®)'s stability. Eight bottles (four completely full, four half-full) of freshly prepared solution were divided into four groups and subsequently stored by being either exposed to or protected from sunlight. The chlorine concentration was monitored using chlorine test strips until the concentration reached zero, or until the thirteenth week. Statistically significant differences between the groups exposed to sunlight and the non-exposed groups (p <0.001) were found. The mean loss of chlorine per day for the non-exposed samples was 1.01 mg/L, whilst the mean for the exposed samples was 2.42 mg/L. The presence of air did not affect the chlorine decomposition in the bottles. The results of this investigation indicate that when the solution is exposed to sunlight, the decrease of chlorine starts at day 4, whilst for the groups sheltered from sunlight, the process started after day 14. Therefore, Sterilox(®) solutions appear to be more stable than previously surmised.

Effect of Aquatine Endodontic Cleanser on smear layer removal in the root canals of ex vivo human teeth

Objectives

The purpose of this study was to measure and compare the root canal cleanliness and smear layer removal effectiveness of Aquatine Endodontic Cleanser (Aquatine EC) when used as an endodontic irrigating solution in comparison with 6% sodium hypochlorite (NaOCl).

Material and Methods

Forty-five human teeth were randomly allocated to five treatment groups; the pulp chamber was accessed, cleaned, and shaped by using ProTaper and ProFile rotary instrumentation to an ISO size #40. The teeth were then processed for scanning electron microscopy, and the root canal cleanliness and removal of smear layer were examined.

Results

The most effective removal of smear layer occurred with Aquatine EC and NaOCl, both with a rinse of EDTA.

Conclusions

Aquatine EC appears to be the first hypochlorous acid approved by the FDA to be a possible alternative to the use of NaOCl as an intracanal irrigant. Further research is needed to identify safer and more effective alternatives to the use of NaOCl irrigation in endodontics.

The antimicrobial effects of root canal irrigation and medication

The role of microorganisms in the development and maintenance of pulpal and periapical inflammation have been well documented. The success of root canal treatment largely depends on the elimination of microbial contamination from the root canal system. Although mechanical instrumentation of root canals can reduce bacterial population, effective elimination of bacteria cannot be achieved without the use of antimicrobial root canal irrigation and medication. This review will discuss the antimicrobial effects of the known root canal irrigants and medicaments and explore future developments in the field.

Cleaning efficacy and dentin micro-hardness after root canal irrigation with a strong acid electrolytic water

The purpose of this study was to evaluate the cleaning effect of root canal walls using strong acid electrolytic water (SAEW) as a root canal irrigant, and to investigate the influence of SAEW on the root canal dentin by micro-hardness test. Forty-three single-rooted, single-canaled teeth were instrumented using standard step-back technique with K-files. Irrigation was performed using distilled water, 5.25% NaOCl and 3% H(2)O(2), SAEW, or 15% EDTA solution in five groups. Samples were prepared to be examined under a scanning electron microscope (SEM) and micro Vickers hardness (H(V)) test machine. Our results showed that the root cleaning effects of the combined use of SAEW and NaOCl solution as root canal irrigants were equivalent to those in the group with NaOCl and 15% EDTA. When SAEW was used for 1 min under ultrasonic vibration, no decreases in the hardness of dentin inside the root canal were detected.

A preliminary assessment ofBacillus anthracisspore inactivation using an electrochemically activated solution (ECASOL™)

AIM

To evaluate the efficacy of electrochemically activated solution (ECASOL) in decontaminating Bacillus anthracis Ames and Vollum 1B spores, with and without changing the source water hardness and final ECASOL pH.

METHODS AND RESULTS

Five different ECASOL formulations were generated, in which the source water hardness and final ECASOL pH were varied, resulting in cases where significant changes in free available chlorine (FAC) and oxidative-reduction potential (ORP) were observed. B. anthracis Ames and Vollum 1B spores were suspended in the various ECASOL formulations for 30 min, and decontamination efficacy was determined; calcium hypochlorite [5% high-test hypochlorite (HTH)] was used as a positive control. The five different ECASOL formulations yielded mean FAC levels ranging from 305 to 464 ppm, and mean ORP levels ranging from +826 to +1000 mV. Exposure to all the ECASOL formulations and 5% HTH resulted in >or=7.0 log reductions in both B. anthracis Ames and Vollum 1B spores.

CONCLUSIONS

The present testing demonstrated that ECASOL with a minimum of c. 300-ppm FAC levels and +800-mV ORP inactivated the B. anthracis spores in suspension, similar to 5% HTH.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results provide information for decontaminating B. anthracis Ames and Vollum 1B spores in suspension using ECASOL.

Root Canal Irrigants

Local wound debridement in the diseased pulp space is the main step in root canal treatment to prevent the tooth from being a source of infection. In this review article, the specifics of the pulpal microenvironment and the resulting requirements for irrigating solutions are spelled out. Sodium hypochlorite solutions are recommended as the main irrigants. This is because of their broad antimicrobial spectrum as well as their unique capacity to dissolve necrotic tissue remnants. Chemical and toxicological concerns related to their use are discussed, including different approaches to enhance local efficacy without increasing the caustic potential. In addition, chelating solutions are recommended as adjunct irrigants to prevent the formation of a smear layer and/or remove it before filling the root canal system. Based on the actions and interactions of currently available solutions, a clinical irrigating regimen is proposed. Furthermore, some technical aspects of irrigating the root canal system are discussed, and recent trends are critically inspected.

An investigation of the efficacy of super–oxidised (Optident/Sterilox) water for the disinfection of dental unit water lines

AIMS

To determine the efficacy of super-oxidised water (Optident/Sterilox) in the decontamination of dental unit water lines.

METHODS

Dental units (10) were first purged with concentrated super-oxidised water. After purging, a 5% (v/v) super-oxidised water was used as a maintenance dose. Samples for microbiology were taken after 0,1,2,3,4,5,6,7 d, and each week for a further 13 weeks.

RESULTS

After purging, 5% (v/v) super-oxidised water was successful in reducing the microbial counts to zero, although in three of the units some bacteria were intermittently isolated in the first week of treatment.

CONCLUSIONS

Super-oxidised water was successful in the removal of bacteria from dental unit water supplies. Complete removal required the treatment with a purge phase of concentrated disinfectant and a maintenance phase of at least two weeks.

Endodontics: Part 5 Basic instruments and materials for root canal treatment

In this part the basic endodontic instruments necessary for effective root canal treatment are described. The properties of, and manufacturer's claims for, new instruments and techniques may be compared to these basic principles before they are purchased and introduced to clinical practice. Having the correct instruments for different clinical situations may make treatment both more efficient and more effective.

Effectiveness of electrochemically activated water as an irrigant in an infected tooth model

AIM

To test the effectiveness of electrochemically activated aqueous solutions in the debridement of Enterococcus faecalis biofilms in root canals of extracted teeth.

METHODOLOGY

Extracted, human, single-rooted teeth (198) assembled into 11 sets (n = 18) with matching anatomical characteristics were randomly assigned to eight experimental groups. After decoronation, the root canals were prepared to a standard size. Enterococcus faecalis biofilms were grown in the root canals of autoclaved, individually mounted teeth over 48 h. Electrolysed saline collected as anolyte at the anode and catholyte at the cathode were the test agents. The four ultrasonication and four without ultrasonication irrigant groups included: neutral anolyte (NA) (pH 6.5), acidic anolyte (AA) (pH 3.0), catholyte (C) (pH 11.5) and C alternated with neutral anolyte (C/NA). Phosphate-buffered saline (PBS) with and without ultrasonication formed negative and NaOCl (3%) positive control groups. After irrigation, root canal samples were serially diluted, cultured and enumerated. The data were analysed as ratios of residual colony-forming units (CFUs) in PBS versus the test irrigants and using multivariate regression.

RESULTS

The NA and NA (ultrasonicated, U), C/NA and AA (U) groups had significantly (alpha = 0.05) less and C (U) and C/NA (U) significantly (alpha = 0.05) more bacteria (CFUs mL(-1)) compared with their respective PBS controls. Ultrasonicated C/NA had significantly (alpha = 0.05) higher CFU counts than the nonultrasonicated solution. Other comparisons between ultrasonic and nonultrasonic groups were not significant. Of the nonultrasonicated groups, C/NA and NA were most effective, whilst of the ultrasonicated groups, AA and NA were most effective. None of these was as effective as 3% NaOCl.

CONCLUSIONS

All but two groups (AA and C) were significantly different from their PBS controls. There was a significant difference between the C/NA groups with and without ultrasonication but not between other combinations. NA (U) and AA (U) were the most effective test solutions but NaOCl (3%) gave by far the highest bacterial kills.