An Overview on a Promising Root Canal Irrigation Solution: QMix

Due to the complex micro-anatomy of the root canal system, mechanical instrumentation leaves significant portions of the root canal walls untouched; therefore, complete elimination of bacteria from the root canal by cleaning with instrumentation alone is unlikely. It has long been postulated but not demonstrated, that any pulp tissue left in the root canals can serve as bacterial/fungal/viral (microorganism nutrients) nutrients. Furthermore, tissue remnants also impede the antimicrobial effects of root canal irrigants and medicaments and prevent intimate adaptation of the root canal filling to the dentin. Therefore, specific irrigation/disinfection procedures are necessary to remove tissue from the root canals and to kill microorganisms, respectively. The purpose of this paper was to review different aspects of a promising root canal irrigant; QMix. This is a relatively new root canal irrigant composed of traditional materials like chlorhexidine (CHX), ethylele diamine tetraacetic acid (EDTA), saline and a detergent. QMix is antibacterial, antifungal and has antibiofilm activities, it displays substantivity, smear layer removing ability; moreover, its effect on dentin and retention of fiber posts etc. has been reviewed. There have been strong reports that show the chemical design of QMix prevents precipitation of CHX when together with EDTA and mixing with sodium hypochlorite does not produce the orange-brown precipitate. Furthermore, the smear layer removal ability of QMix is comparable to that of 17% EDTA and the antibacterial activity of QMix was greater than 1% and 2% sodium hypochlorite (NaOCl) and 2% CHX.

Smear Layer Removing Ability of Root Canal Irrigation Solutions: A Review

AIM

The purpose of this review is to address the smear layer removing the ability of root different canal irrigants including ethylenediaminetetraacetic acid (EDTA), a mixture of tetracycline, acid and detergent (MTAD), tetraclean, citric acid, Q-Mix, maleic acid, and smear clear.

BACKGROUND

Smear layer is a layer which is produced during instrumentation. It contains both organic and inorganic materials. It may also contain bacteria and their byproduct considering the root canal situation. This layer may prevent the penetration of the healing material introduced to the canal to the interior of the dentinal tubules. In addition, it can affect the adaptation of sealing materials to the root canal walls.

REVIEW RESULTS

The smear layer removal ability of MTAD is superior and faster than EDTA. Tetraclean is similarly composed of an acid, an antibiotic, and a detergent. The presence of doxycycline is believed to help the smear layer removal ability of these irrigants. Antibiotics such as tetracycline had similar smear layer removal ability as even citric acid. EDTA is an amino acid with a chelating ability that sequestrates metal ions. Some believed EDTA smear layer removing ability is better than MTAD, tetraclean, SmearClear, and 20% citric acid which is controversial in case of comparison between MTAD and EDTA. Phosphoric acid is efficient enough to be comparable to EDTA in removing the smear layer. Maleic acid is an organic compound with acid etching smear layer removal. Its ability seems to be similar or even better than EDTA. Citric acid as another organic acid is believed to be used as smear removing agent. HEBP is another chelating agent that can be used in combination with NaOCl; however, HEBP is a weak decalcifying agent compared to EDTA and hence cannot be applied as a mere final rinse. QMiX is a combination of CHX, EDTA, and detergent and should be used at final rinse. It is believed that QMiX is as efficient as EDTA. Smear clear is a 17% EDTA solution including an anionic and cationic (cetrimide) surfactant. The ability of QMiX is similar to EDTA.

CONCLUSION

There are different canal irrigation solutions with various smear layer removal ability that some should be used as a mere final rinse and some should not.

CLINICAL SIGNIFICANCE

The usage of canal irrigation solutions depends on the clinical situation and preference of the dentists. This study provides a good guide for clinician of the field.

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.

Photodvnamic Therapy in Endodontics

Commonly used irrigants do not always eradicate the entire microbial flora in infected root canals. Therefore, several other strategies, such as photodynamic therapy (PDT) have been developed. Photoactivated disinfection is based on the interaction of a photosensitive antibacterial agent and a light source. It uses a nontoxic dye named photosensitizer (PS) and low-intensity visible light. In oxygen presentation, these combine to produce some cytotoxic species. The PS molecules attach to bacteria membrane. Irradiation with a specific wavelength of the light may lead to the production of singlet oxygen, resulting in rupture of the microbial cell wall. There are several applications for PDT in dentistry. A successful periodontal treatment is based on elimination of bacteria from the infected area. Phenothiazinium PSs have been shown to be highly effective and safe for this purpose. However, scaling/root planing should be performed before the PDT. While performing the PDT, PS should be first injected in the periodontal pocket and allowed to pigment. Then, the special fiber should be inserted 1 mm short of the pocket base and lased. Photodynamic therapy has also been used to disinfect caries dentin before restoration, disinfecting oral tissues before or during surgical procedures, treating denture stomatitis, and treating oral candidiasis in immunocompromised patients. Photodynamic therapy can be used in combination with mechanical instrumentation and chemical antimicrobial agents, such as sodium hypochlo-rite, too. The purpose of this study was to review historical perspective, mechanism of action, and applications of PDT in dentistry and especially in endodontics was reviewed. Furthermore, the effects of PDT on dentin bonding and endo-toxin are discussed.

CLINICAL SIGNIFICANCE

Photodynamic therapy has been advocated to increase the disinfection level of the root canal system.

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.

Effect of Surfactants on the Efficacy of Root Canal Irrigants: A Review

The mechanical debridement of the root canal system fails to completely remove debris from the root canal walls. So, one or more irrigants must be used for complete disinfection of the root canal system (RCS). One possible way to improve the bactericidal efficacy of the disinfecting solutions is to incorporate different detergents as surface active agents to help reduce the surface tension and increase the wettability of the solutions. Surfactants have been added to various root canal irrigation solutions. The purpose of this paper is to review the effects of adding surfactants to established root canal irrigants and new surfactant-containing root canal irrigants.

Establishing Apical Patency: To be or not to be?

INTRODUCTION

The apical portion of the root canal is very complex and challenging during endodontic treatment. Root canal preparation and obturation to the apical constriction may provide the best prognosis. Incomplete debridement, foramen transportation, and inadequate seal in the apical portion are considered to be responsible for treatment failure. The technique "apical patency" is considered as a way for maintaining the apical part the free of the debris by recapitulation, using a small K-file through the area of the apical foramen. This term was firstly proposed by Buchanan. In this technique, the smallest diameter file is set 1 mm longer than working length and recapitulated after each instrument to prevent packing of debris in the apical part. Apical patency has been found to be effective in achieving an apical seal with gutta-percha. Teeth prepared with a step back method and with maintained apical patency may show less leakage when obturated with cold lateral condensation technique. Data regarding the effect of apical patency on the healing of periapical tissue are very scarce, and it has been shown that the patency file has detrimental effect on the healing of periapical tissues in animal studies. However, using patency file in endodontic treatment is controversial and further studies are needed. The purpose of this article is to review the effect of using a patency file on the extrusion of root canal contents, the apical seal, postoperative pain, and healing of periapical tissues. Furthermore, the effect of establishing patency on reaching irrigation solutions to the apical portion of the canal and prognosis of root canal treatment are discussed.

CLINICAL SIGNIFICANCE

Keywords: Apical patency, Apical seal, Apical transportation, Postoperative pain, Prognosis.

Additive and reducing Effects between Calcium Hydroxide and Current Irrigation Solutions

Microorganisms should be considered to have the major role in starting and perpetuation of pulpo-periapical diseases. Using intracanal medicaments is necessary to gain a bacteria-free environment in the canal system. Calcium hydroxide (abbreviated as Ca(OH)₂), which is the most commonly used medicament in endodontic therapy, has been shown to be effective against primary sources of infection; however, its effectiveness against some microorganisms, such as Candida albicans and Enterococcus faecalis has not been proved. On the other hand, sodium hypochlorite (NaOCl), chlorhexidine (CHX), and iodine potassium iodide (IKI) have been shown to be the potent medicaments against these microorganisms. Because of this fact, combination of Ca(OH)₂ and some irrigants of the root canal has been suggested as potential intracanal medicaments. The aim of this literature review is to identify and address the efficacy of Ca(OH)₂ in combined with some of these irrigating solutions.

Lasers in Apicoectomy: A Brief Review

Since the invention of laser, various applications for lasers in endodontics have been proposed, such as disinfection of the root canal system, canal shaping, pulp diagnosis, and apico-ectomy. One of the major applications of laser in endodontics is apicoectomy. The aim of this article is to review the benefits and drawbacks of laser applications in apicoectomy, including effect on apical seal, effect on dentin permeability, effect on postsurgery pain, effect on crack formation, effect on root-end morphology, effect on treatment outcome, and connective tissue response to laser-treated dentin.

Laser-based Disinfection of the Root Canal System: An Update

Microorganisms have been considered to have played a critical role in the initiation and development of pulpo-periapical diseases. Some evidences have shown that mechanical instrumentation may leave considerable portions of canal surfaces undebrided. Therefore, some supplemental methods, such as the use of chemical solutions and/or lasers, have been introduced to further disinfect the complicated canal anatomy and destroy as many microorganisms as possible. The purpose of this review was to address a brief review of characteristics of lasers and their effects to disinfect the root canal in endodontics.

Postoperative Pain Following Treatment of Teeth with Irreversible Pulpitis: A Review

Patients typically associate dental care with pain. Pain has both physiological and psychological components. Endodontic post-treatment pain continues to be a significant problem facing the dental profession. For patients presenting with preoperative pain, most will continue to experience pain after root canal treatment, with pain levels ranging from mild to severe. The purpose of this paper was to review the symptoms and classification of irreversible pulpitis, including acute and chronic pulpitis, incidence of postoperative pain following treating teeth with irreversible pulpitis, factors influencing postoperative pain, persistent pain after root canal treatment, preventing postoperative pain and pharmacological management of postoperative pain.

Apical Canal Confluency: Clinical and Practical Considerations

Accurate knowledge of canal anatomy is a key factor in the success of root canal treatment. Confluent canals are defined as two canals with a common apical foramen in a root. The purpose of this paper is to review prevalence, instrumentation and obturation of confluent root canals.

Antimicrobial efficacy of chlorhexidine as a root canal irrigant: a literature review

Use of an appropriate root canal irrigant is essential during endodontic treatment, due to the complex and unpredictable anatomy of the root canal system and limitations in the mechanical instrumentation techniques used to obtain a clean, bacteria-free canal. Several irrigants, such as sodium hypochlorite, chlorhexidine, hydrogen peroxide, and normal saline, have been proposed as canal system irrigants in endodontic treatment. The widely used endodontic irrigant chlorhexidine is a positively charged lipophilic/hydrophobic molecule that interacts with phospholipids and lipopolysaccharides on the bacterial cell membrane. In endodontics, its mode of antibacterial activity is determined by its concentration (0.2% or 2%). This article reviews findings from available endodontic studies on the antibacterial, antifungal, and antibiofilm activities of chlorhexidine.

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.

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.

Management of Root Resorption Using Chemical Agents: A Review

Root resorption (RR) is defined as the loss of dental hard tissues because of clastic activity inside or outside of tooth the root. In the permanent dentition, RR is a pathologic event; if untreated, it might result in the premature loss of the affected tooth. Several hypotheses have been suggested as the mechanisms of root resorption such as absence of the remnants of Hertwig's epithelial root sheath (HERS) and the absence of some intrinsic factors in cementum and predentin such as amelogenin or osteoprotegerin (OPG). It seems that a barrier is formed by the less-calcified intermediate cementum or the cementodentin junction that prevents external RR. There are several chemical strategies to manage root resorption. The purpose of this paper was to review several chemical agents to manage RR such as tetracycline, sodium hypochlorite, acids (citric acid, phosphoric acid, ascorbic acid and hydrochloric acid), acetazolamide, calcitonin, alendronate, fluoride, Ledermix and Emdogain.

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.

Genotoxicity of Endodontic Materials: A Critical Review

Genotoxicity is an action on cell's genetic material which may affect its integrity. This includes certain types of radiations and also certain chemical compounds. Genotoxic materials are those with affinity to interact with DNA but render them potentially carcinogenic or mutagenic. This review will address the genotoxicity of endodontic irrigants, medicaments and sealers.

Resilon: Review of a New Material for Obturation of the Canal

Resilon is a thermoplastic synthetic polymer-based endodontic material alternative to gutta-percha. It contains bioactive glass and also radiopaque fillers. It has the same handling properties as gutta-percha. For endodontic retreatment, it may be dissolved with some solvents, such as chloroform or softened with heat. The composition of Resilon and its sealer (Epiphany) bond to dentin and form a monoblock. A review of the literature and a discussion of its properties comparing to other root canal filling materials are presented.

Root and Root Canal Morphology of Human Third Molar Teeth

Successful root canal treatment depends on having comprehensive information regarding the root(s)/canal(s) anatomy. Dentists may have some complication in treatment of third molars because the difficulty in their access, their aberrant occlusal anatomy and different patterns of eruption. The aim of this review was to review and address the number of roots and root canals in third molars, prevalence of confluent canals in third molars, C-shaped canals, dilaceration and fusion in third molars, autotransplantation of third molars and endodontic treatment strategies for third molars.

Effect of apically separated rotary instruments on bacterial leakage of obturated root canals using resilon

The purpose of this study was to determine the effect of a separated rotary instrument on the time required for bacterial penetration of obturated root canals using Resilon. Eighty-four extracted human maxillary premolars with single canals were used in this study. Group 1 consisted of teeth obturated with gutta-percha and AH-26 sealer (n=15); Group 2 consisted of teeth obturated similarly to Group 1 but without a separated file; Group 3 consisted of teeth obturated with Resilon and Epiphany sealer (n=15); and Group 4 consisted of teeth obturated similarly to Group 3 but without a separated file. Six teeth were used as positive controls, and six teeth were used as negative controls for each experimental group. Negative controls were obturated similarly to experimental teeth. On the other hand, positive controls were obturated with gutta-percha or Resilon without sealer. A suspension of Enterococcus faecalis was placed in the access chamber daily, and penetration was determined when turbidity was noted in the culture broth during a three-month period. No significant difference between experimental groups was observed. However, differences between experimental groups and control groups were statistically significant.

Mineral trioxide aggregate (MTA)-like materials: an update review

Mineral trioxide aggregate (MTA) is a multi-application material used in endodontics. It is a mixture of a refined Portland cement and bismuth oxide and trace amounts of SiO₂, CaO, MgO, K₂SO₄, and Na₂SO₄. MTA powder is mixed with supplied sterile water in a 3:1 powder/liquid. Hydrated MTA has an initial pH of 10.2, which rises to 12.5 three hours after mixing. There are several materials derived from MTA such as Endo-CPM Sealer, Ortho MTA, MTA-Fillapex, DiaRoot BioAggregate, MTA Bio, light-cured MTA, tricalcium silicate, and iRoot SP. The purpose of this article is to review MTA-like materials.

Antifungal effects of root canal irrigants and medicaments. An update review

Fungi, especially Candida albicans, play an important role in persistent/secondary endodontic infections. There are several irrigants and medicaments in the field of endodontics. The purpose of this paper is to review the antifungal activity of sodium hypochlorite, chlorhexidine, MTAD, Tetraclean, EDTA, calcium hydroxide and MTA.

Determining the minimum inhibitory concentration of Tetraclean against Candida albicans

The purpose of the present study was to determine the minimum inhibitory concentrations of Tetraclean, chlorhexidine, hydrogen peroxide, and sodium hypochlorite against Candida albicans.Amphotericin B was used as positive control and RPMI plus 1 ml Candida suspension was used as negative control. Serial dilution method was used to determine MIC of the irrigants. Findings showed that all positive controls demonstrated complete inhibition of C. albicans at concentration of 0.78 microg mL(-1). On the other hand, all negative controls were positive for fungal growth which confirms the methodology of the study. Findings showed that the MIC of CHX was significantly lesser than other tested irrigants (p < 0.05). The MICs of other groups in an ascending order were as follows: Tetraclean, NaOCl, and H2O2. However, the difference betweenTetraclean and NaOCI was not significant (p > 0.05). It can be concluded that MIC of CHX was significantly lower than other irrigations solutions which confirms its strong antifungal activity.

Ethylenediaminetetraacetic acid in endodontics

Ethylenediaminetetraacetic acid (EDTA) is a chelating agent can bind to metals via four carboxylate and two amine groups. It is a polyamino carboxylic acid and a colorless, water-soluble solid, which is widely used to dissolve lime scale. It is produced as several salts, notably disodium EDTA and calcium disodium EDTA. EDTA reacts with the calcium ions in dentine and forms soluble calcium chelates. A review of the literature and a discussion of the different indications and considerations for its usage are presented.

Calcium hydroxide-based root canal sealers: an updated literature review

Calcium hydroxide was originally introduced to the field of endodontics by Herman in 1920 as a pulp-capping agent. Sealers play an important role in sealing the root canal system with the entombment of remaining microorganisms and filling inaccessible areas of prepared canals. This article reviews sealing ability, biocompatibility, antibacterial activity, solubility, and toxicity of calcium hydroxide based root canal sealers.

Effect of irrigation with Tetraclean on bacterial leakage of obturated root canals

The purpose of the study presented here was to evaluate the effect of Tetraclean, Hypoclean, Chlor-XTRA, 2% chlorhexidine and 6% sodium hypochlorite/17% EDTA as a final irrigant on bacterial leakage of the root canal. One hundred and fifty-five extracted human maxillary central incisors were randomly divided into five experimental groups of 25 teeth each and two control groups of 15 teeth each. The root canals in each group were irrigated with 2 ml of the relevant irrigant between each filing. The root canals in group 5 were irrigated with 5 ml of 17% EDTA at the end of root canal preparation. The teeth in each group were obturated with gutta-percha and AH-26 sealer. Positive control teeth were obturated with a single gutta-percha cone without sealer, and negative controls were obturated in the same way as experimental groups. The coronal portion of each root was placed in contact with inoculum of Enterococcus faecalis in Brain Heart Infusion (BHI) culture media. Findings showed that the mean number of days for bacterial penetration in the Tetraclean group was greater than for other experimental groups. On the other hand, the Chlor-XTRA Vista group showed the fewest mean number of days for bacterial leakage.

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.

Microbial biofilms in endodontic infections: an update review

Biofilms and microbial aggregates are the common mechanisms for the survival of bacteria in nature. In other words, the ability to form biofilms has been regarded as a virulence factor. Microbial biofilms play an essential role in several infectious diseases such as pulp and periradicular pathosis. The aim of this article was to review the adaptation mechanisms of biofilms, their roles in pulpal and periapical pathosis, factors influencing biofilm formation, mechanisms of their antimicrobial resistance, models developed to create biofilms, observation techniques of endodontic biofilms, and the effects of root canal irrigants and medicaments as well as lasers on endodontic biofilms. The search was performed from 1982 to December 2010, and was limited to papers in English language. The keywords searched on Medline were "biofilms and endodontics," "biofilms and root canal irrigation," "biofilms and intra-canal medicament," and "biofilms and lasers." The reference section of each article was manually searched to find other suitable sources of information.

Extra roots and root canals in premolar and molar teeth: review of an endodontic challenge

The main goal of endodontic treatment is healing of the periapical tissues which are gained by elimination of bacteria and their byproducts from the canal and prevention from reinfection. Understanding of root canal anatomy is an essential part in endodontic treatment. Anatomic forms and variations in special teeth should be well known, one of them is extra roots/ canals. Although possible aberrations of canal anatomy should be considered for all teeth, some teeth should be highlighted. This review addresses the prevalence, diagnosis (clinical and radiographic), and endodontic management of teeth with extra roots/canals.

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.

Antimicrobial activity of sodium hypochlorite in endodontics

One of the major objectives in endodontic therapy is to disinfect the entire root canal system. This goal may be achieved using mechanical instrumenation and chemical irrigation in conjunrction with medication of the root canal between treatment sessions. Microorganisms and their by-products are considered to be the major cause of pulpal and periradicular patholic. In order to reduce or eliminate bacteria and popular tissue remnants, the use of various irrigation solution during treatment have been suggested. Sodium hypochlorite (NaOCI), the most common irrigant, is an excellent nonspecific proteolytic and antimicrobial agent. The purpose of this paper is to review the antimicrobial activity of sodium hypochlorite.

Substantivity of three concentrations of tetraclean in bovine root dentin

In the present study, the residual antibacterial activity, or substantivity, of three concentrations of Tetraclean (Ogna Laboratori Farmaceutici, Muggiò, Italy) was assessed in bovine root dentin in vitro. One hundred ten dentin tubes prepared from bovine incisor teeth were infected in vitro for 14 days with Enterococcus faecalis. Thereafter, the specimens were divided into five groups as follows: 100% Tetraclean, 10% Tetraclean, 1% Tetraclean, sterile dentin tubes (negative control), and infected dentin tubes (positive control). Dentin chips were collected with round burs into tryptic soy broth and, after culturing, the number of colony-forming units (CFU) was counted. The number of CFU was minimal in the first cultures in all experimental groups, and the results obtained were significantly different in the different groups at all time periods (p<0.05). At all five experimental periods, the 100% Tetraclean group showed the most effective antibacterial action (p<0.05). In each group, the number of CFU increased significantly with time (p<0.05). There was a direct relationship between the concentration of Tetraclean and its substantivity. In conclusion, under the conditions of the study presented here, the substantivity of 100% Tetraclean was significantly higher than that of lower concentrations.

Antimicrobial activity of calcium hydroxide in endodontics: a review

The purpose of endodontic therapy is to preserve the patient's natural teeth without compromising the patient's local or systemic health. Calcium hydroxide has been included in several materials and antimicrobial formulations that are used in several treatment modalities in endodontics, such as inter-appointment intracanal medicaments. The purpose of this article was to review the antimicrobial properties of calcium hydroxide in endodontics. Calcium hydroxide has a high pH (approximately 12.5-12.8) and is classified chemically as a strong base. The lethal effects of calcium hydroxide on bacterial cells are probably due to protein denaturation and damage to DNA and cytoplasmic membranes. Calcium hydroxide has a wide range of antimicrobial activity against common endodontic pathogens but is less effective against Enterococcus faecalis and Candida albicans. Calcium hydroxide is also a valuable anti-endotoxin agent. However, its effect on microbial biofilms is controversial.

Clinical applications of glass ionomers in endodontics: a review

Glass ionomer cements (GICs) are biocompatible and have capacities to release fluoride and to bond to dentine, and thus are appropriate for use in endodontics. This paper reviews the composition and properties of different GICs, including their biocompatibility and antibacterial activity, their applications as intraorifice barriers and root canal sealers, and their use in the repair of root perforations, root-end fillings and temporary coronal restorations.

Antimicrobial effect of three new and two established root canal irrigation solutions

This study sought to assess the efficacy of two established and three relatively new root canal irrigants against five different microorganisms using the agar diffusion method. Sodium hypochloride (NaOCl)-based irrigants demonstrated the most effective antimicrobial activity.

Antibacterial activity of a new mineral trioxide aggregate-based root canal sealer

OBJECTIVES

To compare the antibacterial effect of AH-26, white-coloured mineral trioxide aggregate (WMTA) and CPM sealer against Staphylococcus aureus and Streptococcus mutans after 24 h and 1 week.

MATERIALS AND METHODS

All materials were prepared according to the manufacturers' directions immediately before testing. The antibacterial effect of each agent was determined by measuring the diameter of the zone of inhibition in millimetres after incubation at 37°C for 24 h and 7 days in a humid atmosphere. Each test was repeated three times.

RESULTS

In the 24-h and 7-day samples, the antibacterial activity of AH-26 was significantly greater than that of the two other materials tested against both bacteria (P < 0.05). The antibacterial activities of CPM sealer and WMTA against S. aureus were not significantly different (P > 0.05) in 24-h or 7-day samples, but CPM sealer demonstrated a significantly greater effect than WMTA against S. mutans (P < 0.05).

CONCLUSION

All products studied exhibited antibacterial activity. However, in 24-h and 7-day samples, AH-26 exerted the greatest activity against both organisms tested.

Is chlorhexidine an ideal vehicle for calcium hydroxide? A microbiologic review

Microorganisms play a major role in the initiation and perpetuation of pulpal and periapical disease. In order to predictably achieve a bacteria-free root canal system, it is necessary to use intracanal medicaments. Calcium hydroxide [Ca(OH)(2)] is the most common intracanal medicaments. It is effective against primary infections. However, its effectiveness against Enterococcus (E.) faecalis and Candida (C.) albicans is controversial. On the other hand, chlorhexidine (CHX) is a potent agent against E. faecalis and C. albicans. For this reason, the combination of Ca(OH)(2) and CHX has been suggested as an intracanal medicament. The purpose of this article was to review antimicrobial efficacy of Ca(OH)(2), CHX as well as their combination.

The effect of ascorbic Acid on the substantivity of tetraclean in sodium hypochlorite-treated bovine dentin

OBJECTIVE

The purpose of this study was to assess the in vitro effect of ascorbic acid on the antibacterial substantivity of Tetraclean in bovine root dentin pretreated with sodium hypochlorite (NaOCl).

MATERIALS AND METHODS

Eighty dentin tubes prepared from bovine incisor teeth were infected with Enterococcus faecalis for 14 days. The specimens were divided into five groups as follows: Tetraclean; 5.25% NaOCl/Tetraclean; 5.25% NaOCl/ascorbic acid/Tetraclean; infected dentin tubes (positive control); and sterile dentin tubes (negative control). At experimental times of 0, 7, 14, 21 and 28 days, dentin chips were removed from the canals by sequential sterile low-speed round burs with increasing diameters of 025, 027, 029, 031 and 033 ISO sizes, respectively. After culturing, the number of colony-forming units (CFU) was counted.

RESULTS

In all experimental groups, the number of CFU was minimum in the first cultures and the results obtained were significantly different at any time period (p < 0.05). The Tetraclean group showed the most effective antibacterial action at all five experimental periods (p < 0.05). NaOCl/Tetraclean group showed the least antibacterial activity at all time periods. The NaOCl/ascorbic acid/Tetraclean group showed similar antibacterial substantivity to the Tetraclean group at all time periods (p> 0.05).

CONCLUSION

Ascorbic acid prevents the decrease of residual antibacterial activity of Tetraclean in dentin samples pretreated with NaOCl.

Non-Surgical Repair of Internal Resorption with MTA: A Case Report

Internal resorption is rare in permanent teeth. Treatment is usually performed through warm gutta-percha technique. If the resorptive process perforates the root, treatment may be more difficult and is usually performed via surgical approach. Non-surgical repair of a perforating internal root resorption with MTA was conducted in this case. Before repairing the resorption, a master gutta-percha point was placed in the canal to maintain negotiability of the original canal path. Then, MTA was prepared and applied with a small carrier in the resorption area and compacted. Thereafter gutta-percha was retrieved and the access cavity was closed with a temporary filling material. In the second visit, the root canal was obturated with gutta-percha and AH26 sealer using lateral compaction technique and subsequently, the crown was restored. The symptoms and signs ceased and the result was satisfactory at the 18 month follow-up visit.

The effect of heat-killed Candida albicans and dentin powder on the antibacterial activity of chlorhexidine solution

INTRODUCTION

The purpose of this study was to compare the inhibitory effect of heat-killed Candida albicans and dentin powder on the antibacterial activity of chlorhexidine (CHX) against Enterococcus faecalis and Streptococcus sanguis.

MATERIALS AND METHODS

The antibacterial effect of each group was determined by measuring the zone of inhibition diameter in millimeters after incubation at 37°C for 24 hours in a humid atmosphere. Each test was repeated three times. Data were analyzed using ANOVA and Tukey's test.

RESULTS

Results indicated that both heat-killed C. albicans and dentin powder decreased the antibacterial activity of CHX against both tested bacteria significantly (P<0.05).

CONCLUSION

In conclusion, both heat-killed Candida albicans and dentin powder reduced the antibacterial activity of CHX significantly.

Root canal treatment of maxillary and mandibular three-rooted premolars: case reports

Familiarity with the normal and abnormal anatomy of the root canal system is essential for successful root canal treatment. The possibility of concomitant three-rooted and three- canalled maxillary and mandibular premolars are extremely rare. The purpose of this paper was to report a case with a three-rooted maxillary first premolar and two three-rooted mandibular premolars.

Effect of Hydroxyapatite and Bovine Serum Albumin on the Antibacterial Activity of MTA

INTRODUCTION

The purpose of this study was to compare the inhibitory effect of bovine serum albumin (BSA) and hydroxyapatite (HA) on the antibacterial activity of white-colored MTA (WMTA) against Staphylococcus (S.) aureus and Streptococcus (S.) mutans after 24 and 72 hours.

MATERIALS AND METHODS

All materials were prepared according to the manufacturer's directions immediately before testing. The antibacterial effect of each group (WMTA, WMTA+BSA and WMTA+HA) was determined by measuring the diameter of zone of inhibition in millimeters after incubation at 37°C for 24 and 72 hours in a humid atmosphere. Each test was repeated three times. Data were analyzed using ANOVA and Tukey's test.

RESULTS

In the 24 hours samples as well as in 72 hours samples, the antibacterial activity of MTA+HA group was significantly greater than two other groups against S. aureus (P<0.05). However, the antibacterial activity of MTA+HA group against S. mutans was not significantly different from the MTA group in 24 hours as well as 72 hours samples. BSA reduced the antibacterial activity of MTA against both tested bacteria in the 24 and 72 hour samples (P<0.05).

CONCLUSION

The products studied exhibited antibacterial activity. However, in both time intervals, the MTA+HA group exerted the greatest activity against S. mutans and S. aureus.