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.

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.

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.

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.

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.

INTRODUCTION: 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.

Additive and reducing Effects between Calcium Hydroxide and Current Irrigation Solutions.

INTRODUCTION: 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.