Original Article

Comparing the Efficacy of Mtwo and D-RaCe Retreatment Systems in Removing Residual Gutta-Percha and Sealer in the Root Canal

Hengameh Akhavan, Yaser Khalil Azdadi, Shahram Azimi, Bahare Dadresanfar, Anahid Ahmadi

Iranian Endodontic Journal, Vol. 7 No. 3 (2012), 28 July 2012 , Page 122-126

Introduction: Retreatment is performed in teeth with unsuccessful root canal therapy or persistent apical lesion. The most important factor for achieving successful retreatment is thorough cleaning and reshaping. NiTi files and rotary instruments are widely used for the removal of obturatants. This study compared the ability of Mtwo and D-RaCe retreatment systems to remove residual gutta-percha and sealer within the root canal after retreatment.

Materials and Methods: This in vitro experiment was performed on sixty extracted human teeth. The samples were cut at the CEJ level, manually prepared, filled with gutta-percha  and AH26 and finally stored at 37ºC for two weeks. Samples were then randomly divided into two groups. Group 1 was retreated with Mtwo and Group 2 with D-RaCe. Both groups were then divided into two subgroups retreated either with or without solvent. Teeth were then vertically sectioned for evaluation of residual filling materials on the canal walls. A microscopic assessment at 16× magnification was performed. T-test statistical analysis was used to compare the data.

Results: Comparison between the Mtwo and D-RaCe rotary systems revealed no significant differences in residual gutta-percha or sealer on canal walls (P=0.2). The study revealed a negative effect of solvent on removal of gutta-percha and sealer in both the Mtwo and D-RaCe systems.

Conclusion: Mtwo and D-RaCe retreatment files removed residual gutta-percha and sealer similarly; there was no significant difference between them.

Propolis: A New Alternative for Root Canal Disinfection

Maryam Zare Jahromi, Hasan Toubayani, Majid Rezaei

Iranian Endodontic Journal, Vol. 7 No. 3 (2012), 28 July 2012 , Page 127-133

Introduction: This study evaluated and compared colony forming units (CFUs) and minimum inhibitory concentrations (MICs) of calcium hydroxide and propolis as intracanal medicaments.

Materials and Methods: Eighty human single-root and caries-free teeth were selected and divided into five groups. Crowns were removed. Root canals were then prepared in a step-back manner. The samples were then inoculated by Enterococcus (E.) faecalis and incubated for 21 days. Intracanal medications were applied including, calcium hydroxide (n=20), propolis (n=20), and ethanol (n=20). Two groups of 10 teeth were also used as the positive and negative controls. Microbiological sampling was performed utilizing a piezo-reamer drill after one week of incubation. The samples were plated and CFUs were counted after 48 hours. MICs of calcium hydroxide and propolis were measured by serial dilution and agar dilution methods, respectively. The statistical tests of ANOVA and Duncan post-hoc were used to compare different medications.

Results: MICs and CFUs of propolis were dramatically less than calcium hydroxide. The difference between the groups was statistically significant (P<0.001).

Conclusion: Our results reveal that propolis is an effective antimicrobial intracanal agent.

Evaluating the Effect of Resection on the Sealing Ability of MTA and CEM Cement

Amin Salem Milani, Sahar Shakouie, Zahra Borna, Alireza Sighari Deljavan, Mohammad Asghari Jafarabadi, Fatemeh Pournaghi Azar

Iranian Endodontic Journal, Vol. 7 No. 3 (2012), 28 July 2012 , Page 134-138

Introduction: In cases of limited access to the surgical site, an alternative approach is to obturate the canal prior to surgery. Endodontic surgery is subsequently performed by root-end resection without retro-cavity preparation. This in vitro study was designed to compare the sealing ability of resected roots filled with either mineral trioxide aggregate (MTA) or calcium enriched mixture (CEM) cement.

Materials and Methods: Seventy maxillary anterior teeth were selected. Following canal preparation, the teeth were randomly divided into four experimental (n=15) and two control (n=5) groups. In Group 1, CEM cement was placed into the apical 6-mm of the canal. The remainder of the canal was filled with gutta-percha/AH26 and 3-mm root-ends were resected. In Group 2: the teeth were treated as described above except that MTA was used instead of CEM cement. Group 3: The canals were obturated with gutta-percha/AH26. After root-end resection, retro cavities were prepared and filled with CEM cement. Group 4: The teeth were treated as described for group 3 except that MTA was used instead of CEM cement. The root apices of teeth were then placed in India ink, and maximum dye penetration was measured with a stereomicroscope. Nested ANOVA and Independent samples t-test were used to evaluate the statistical significance.

Results: The mean dye leakage values for groups 1 to 4 were 402.6, 526.4, 141.0, and 177.4, respectively. The retrofilled groups had less microleakage compared to the resected materials; in the CEM cement groups this was statistically significant (P<0.05), i.e. root-end resection had no significant influence on the sealing ability of MTA, but significantly increased the microleakage of CEM cement (P=0.017). Overall, CEM cement showed less microleakage compared to MTA, however the difference was not significant.

Conclusion: Within the limitations of this dye leakage study, we can conclude that if limited access prohibits retrofill placement, MTA or CEM cement can be used to fill the canal prior to root-end resection; as they have similar sealing ability. However, further laboratory and clinical studies are required to evaluate this alternative method.

A Comparative Study of the Microleakage of Resilon/Epiphany and Gutta-Percha/AH-Plus Obturating Systems

Elmakki Fathia, Neamat Hassan Abu-bakr, Ibrahim Yahia

Iranian Endodontic Journal, Vol. 7 No. 3 (2012), 28 July 2012 , Page 139-143

Introduction: The aim of the present study was to investigate and compare the apical sealing ability of Resilon/Epiphany-filled root canals with those that were obturated with gutta-percha/AH-Plus endodontic sealer.

Materials and Methods: A total of 60 extracted human single-rooted teeth were selected; 25 teeth for each test group and five for each control group. After conducting conventional endodontic treatment, the teeth were immersed in physiologic saline solution for thirty days, and subsequently sealed and stored in methylene blue dye solution for seven days. The teeth were sectioned to evaluate the linear apical leakage using a stereoscopic microscope. The data were statistically analyzed by non-parametric Kruskal-Wallis and Mann-Whitney U tests.

Results: The results showed significant differences between the two groups of endodontic sealers (P<0.001).

Conclusion: Within the limitation of the present in vitro study, Resilon/Epiphany sealer had better apical sealing ability than gutta-percha/AH-Plus sealer.

Subcutaneous Tissue Responses to Three Endodontic Irrigants: A Comparative Study

Kazem Ashofteh Yazdi, Mohammad Sabeti, Pooriya Motahhary, Alireza Kolahdouzan, Mohsen Shayesteh, Noushin Shokouhinejad

Iranian Endodontic Journal, Vol. 7 No. 3 (2012), 28 July 2012 , Page 144-148

Introduction: This study aimed to compare the subcutaneous tissue responses to MTAD (mixture of a tetracycline isomer, an acid, and a detergent), 17% EDTA, and 2.6% NaOCl.

Materials and Methods: Thirty-six Wistar albino rats were used for this study.  Test solutions were injected subcutaneously into predetermined areas on the animal dorsum. The rats were then randomly divided into three groups of twelve each and sacrificed at 2 hours, 2 days, and 2 weeks. The severity of inflammation induced by each irrigant at different time intervals was assessed histologically. The data were analyzed using Kruskal-Wallis and Friedman tests.

Results: The difference in severity of inflammatory reactions induced by tested irrigants at the different time intervals was statically significant (P<0.05). There was no significant difference between the severity of inflammation induced by MTAD and 2.6% NaOCl at the various time intervals (P>0.05). Subcutaneous tissue responses to MTAD were not different from those observed in 17% EDTA specimens at 2-hour and 2-day intervals (P>0.05).

Conclusion: Under the conditions of this study, MTAD has the same toxicity as 2.6% NaOCl.

A Comparison between the Antimicrobial Effects of Triple Antibiotic Paste and Calcium Hydroxide against Entrococcus Faecalis

Alireza Adl, Nooshin Sadat Shojaee, Mohamad Motamedifar

Iranian Endodontic Journal, Vol. 7 No. 3 (2012), 28 July 2012 , Page 149-155

Introduction: The purpose of this study was to determine the in vitro antimicrobial ability against Entrococcus (E.) faecalis of triple antibiotic paste and its components compared with calcium hydroxide mixtures.

Materials and Methods: An agar well diffusion assay and MIC method were used to determine the efficacy of the experimental medicaments in removing E. faecalis. Medicaments were divided into 9 groups; triple antibiotic powder with saline or chlorhexidine, metronidazole, ciprofloxacin, minocycline antibiotics were also separately tested (with normal saline), and Ca(OH)2 (plus normal saline or 2% chlorhexidine). These medicaments were evaluated at four concentrations of 25, 50, 100 and 200 µg per mL in an agar well diffusion test. The diameters of the growth inhibition zones for each group were recorded and compared. The minimum inhibitory concentrations (MIC) of tested medicaments that are required to kill E. faecalis were also determined. The differences between groups were analyzed by Kruskal-Wallis and Mann-Whitney U tests.

Results: The largest inhibition zones were observed for the triple antibiotic mixture/saline, triple antibiotic mixture/2% chlorhexidine and minocycline/saline, and the smallest for Ca(OH)2/saline, Ca(OH)2/2% chlorhexidine. Concentration increases produced greater antibacterial effects in all groups. The MIC determination method showed similar results.

Conclusion: The results suggest that the triple antibiotic paste with either 2% chlorhexidine or normal saline would be the preferred medicament against E. faecalis and, among its three components, minocycline has the greatest antibacterial effect.

An In Vitro Comparison of Coronal Microleakage of Three Orifice Barriers Filling Materials

Hamidreza Yavari, Mohammad Samiei, Mahsa Eskandarinezhad, Shahriar Shahi, Marzieh Aghazadeh, Yones Pasvey

Iranian Endodontic Journal, Vol. 7 No. 3 (2012), 28 July 2012 , Page 156-160

Introduction: A coronal barrier in root-filled teeth is one of the most effective methods for prevention of coronal microleakage. The aim of this study was to compare coronal microleakage of three materials [light-cured glass-ionomer (GI), mineral trioxide aggregate (MTA), and composite resin] as coronal barriers.

Materials and Methods: A total of 188 intact maxillary incisors were used. After instrumentation, all the canals were obturated with gutta-percha and lateral condensation technique using AH26 sealer. Then, the teeth were sectioned just apical to the cemento-enamel junction. The roots were randomly assigned to three experimental groups (n=56) and two negative and positive control groups (n=20). After placing the orifice barrier, the samples were immersed in 2% methylene blue solution for 2 weeks at 37°C. Then the teeth were longitudinally sectioned mesiodistally and dye penetration was measured under a stereomicroscope at ×10 magnification. Data were analyzed with one-way ANOVA and a post-hoc Tukey test.

Results: The positive control group leaked significantly more than all the experimental groups (P=0.001). MTA exhibited less leakage than composite and GI (P=0.002) but no significant differences were found between GI and composite groups.

Conclusion: Immediate placement of a suitable intra-orifice barrier like MTA, before final restoration, may help minimize recontamination of the remaining apical gutta-percha.

Case Report

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

Susan Shalavi, Zahed Mohammadi, Maryam Abdolrazzaghi

Iranian Endodontic Journal, Vol. 7 No. 3 (2012), 28 July 2012 , Page 161-164

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.

Apexification with a New Intra-Canal Medicament: A Multidisciplinary Case Report

Adriana Jesus Soares, Juliana Yuri Nagata, Renato Corrêa Viana Casarin, José Flávio Affonso Almeida, Brenda Paula Figueiredo de Almeida Gomes, Alexandre Augusto Zaia, Caio Cezar Randi Ferraz, Francisco José Souza-Filho

Iranian Endodontic Journal, Vol. 7 No. 3 (2012), 28 July 2012 , Page 165-170

Dental trauma generally requires multidisciplinary planning and treatment for good prognosis. When immature teeth are traumatized to a degree where pulp necrosis ensues, the objective of root canal treatment should be apexogenesis and root maturation. Apexification of the root is the conventional choice, which involves cleaning the canal and filling it with a temporary medication that stimulates the formation of a calcific apical barrier. Dental Trauma Service of Piracicaba Dental School, State University of Campinas (UNICAMP), Brazil employs a dressing for apexification treatments with calcium hydroxide, chlorhexidine gel 2% and zinc oxide. This paper reports the case of a dental trauma of the maxillary central incisors and subluxation on teeth 11, 12 and 21 that were treated with multidisciplinary collaboration (Endodontics, Periodontology and Operative Dentistry) to improve prognosis. After five-years there were no pathological conditions and the teeth showed every evidences of success.

Review Article

Is chlorhexidine an ideal vehicle for calcium hydroxide?

Zahed Mohammadi, Sousan Shalavi

Iranian Endodontic Journal, Vol. 7 No. 3 (2012), 28 July 2012 , Page 115-122

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 is the most common intracanal medicaments. It is effective against primary infections. However, its effectiveness against Enterococcus faecalis and Candida albicans is controversial. On the other hand, chlorhexidine is a potent agent against Enterococcus faecalis and Candida albicans. For this reason, it has been combination of calcium hydroxide and chlorhexidine has been suggested as an intracanal medicament. The purpose of this article was to a brief review antimicrobial efficacy of calcium hydroxide, chlorhexidine, and their combination.


Review of High Level Endodontic Research in PubMed Index Journals from Iran

Mohammad Jafar Eghbal, Hassan Torabzadeh

Iranian Endodontic Journal, Vol. 7 No. 3 (2012), 28 July 2012 , Page 109-114

Introduction: This study aimed to evaluate patents as well as high level researches including systematic reviews/meta-analyses and randomized controlled clinical trials (RCT) published in scientific journals by Iranians endodontic.

Materials and Methods: The study started with targeted searches of PubMed as well as World Intellectual Property Organization and United State Patent and Trademark Office.

Results: There were 4 filed/granted patents, 2 systematic reviews/meta-analyses and 25 RCTs. Patents were related to endodontic/dental (bio)materials. Performing a topic sorting, 15 RCTs were about vital pulp therapy and 8 about anesthesia and pain. More than 55% of these articles originated from three University of Medical Sciences: Shahid Beheshti (22.2%), Kerman (18.5%) and Mashad (14.8%).

Conclusion: Vital pulp therapy was the most important topic amongst endodontic high level evidence articles.