Iranian Endodontic Journal

INTRODUCTION: Mineral trioxide aggregate (MTA) is an endodontic material with different clinical applications e.g. root-end filling, pulp capping and perforation repair.  It has been reported to possess antimicrobial and antifungal activities. The aim of this study was to examine the effect of White MTA on formalin-induced hyperalgesia in a rat with inflammatory pain. MATERIALS AND METHODS: Inflammatory pain was induced by subcutaneous (SC) injection of formalin (40 µL, 2.5%) into the rat upper lip. The nociceptive behavioral responses i.e. shaking of the lower jaw and face rubbing were quantified. 40 µL of eugenol (50 mg/kg), WMTA (20 mg/0.2 mL) or ketoprofen were injected solely or in combination with formalin 2.5% and the behavioral responses were compared with those observed after formalin treatment alone. One-way ANOVA, Tukey were used for analysis of data. RESULTS: Formalin 2.5% provoked a biphasic nociceptive response, with an early and short lasting first tonic phase followed by a second phase. Solely SC injection of either WMTA or ketoprofen (a non steroidal anti-inflammatory drug) did not stimulate any significant nociceptive behaviour. However, injection of eugenol (a pain relieving agent) induced the early phase not the tonic phase of nociceptive response. WMTA, eugenol or ketoprofen injection 20 min before formalin injection attenuated the first phase but somehow prevented the induction of the second phase of nociceptive responses which were produced by formalin. Behavioural nociceptive responses including shaking of the lower jaw and face rubbing were significantly reduced when the subject was pretreated with either WMTA or ketoprofen (P<0.001). CONCLUSION: In this study, WMTA induced pain reduction by suppression of the formalin-induced nociceptive response.

INTRODUCTION: Sealing ability of root-end filling materials is of great importance. It can be investigated by measuring microleakage. The purpose of this in vitro study was to evaluate microleakage of calcium enriched mixture (CEM) cement in two different media including phosphate buffer solution (PBS) and distilled water. MATERIALS AND METHODS: Twenty single-rooted human teeth were selected. All teeth were root-end filled with CEM cement. Samples were divided into two groups of 10 each and were placed in PBS or distilled water. The microleakage was measured after 12 and 24 h, 14 and 30 days with Fluid Filtration device. Data were statistically analyzed by repeated measures test. RESULTS: Sealing ability of CEM cement was significantly superior in PBS compared to distilled water (P<0.05). This study also showed that time had no significant effect on the sealing ability of CEM cement. CONCLUSION: Media can significantly affect the microleakage of CEM cement. PBS can provide more phosphorous ions for hydroxyapatite formation of CEM cement; therefore, CEM cement can seal more effectively with PBS.

INTRODUCTION: The aim of this study was to compare centering ability and dentin removal of three rotary systems in curved root canals of extracted teeth. MATERIALS AND METHODS: Sixty root canals of mandibular first molars with curvatures ranging between 25-35^o were divided into three groups of 20 teeth each. Based on pre-instrumentation radiographs that assessed the angle and the radius of canal curvatures, teeth with curvatures were equally spread between the three groups. The root canals were sectioned horizontally at two levels before preparation and then remounted onto the muffle. All root canals were prepared using a low-torque control motor with Mtwo or Medin or Race instruments. Cross sectional images were obtained before and after instrumentation. Cross-sectional area and centering ability were evaluated. The data were analyzed using the one-way ANOVA and Tukey tests. RESULTS: Neither instrument fracture nor permanent deformation occurred during preparations. The best centering ability was obtained by Mtwo instruments compare to Race and Medin instruments. In the coronal and middle sections, Mtwo removed less dentin than Race and Medin; while the difference in the apical section was not significant. CONCLUSION: Under the conditions of this study, the debridement of root canals was more conservative with Mtwo. The canals prepared with these instruments were better centered in all three regions of the root.

INTRODUCTION: Sodium hypochlorite (NaOCl) is an effective antimicrobial irrigant, however its toxic effects and deterrent odor are not ideal. Carvacrol is an edible plant extract with anti-inflammatory and anti-bacterial properties that is effective against Enterococcus (E) faecalis. The aim of this study was to evaluate Carvacrol's antibacterial efficacy against E. faecalis bacteria as a final irrigant. MATERIALS AND METHODS: Forty extracted single-rooted human teeth were utilized. After mechanical preparations, samples were randomly divided into three experimental (A, B and C) and two control groups. E. faecalis was cultured in both experimental and positive control groups. After bacterial counting in all canals, 5.25% NaOCl, 0.6% Carvacrol emulsion and MTAD were used as final irrigants in groups A, B and C respectively. Data were analyzed using Kruskal-Wallis and Mann-Whitney U tests. RESULTS: There was no meaningful difference in bacterial reduction between groups A and B; however, group C showed significantly lower efficacy compared to other groups (P<0.05). CONCLUSION: The 0.6% Carvacrol disinfects root canals effectively. It also has anti-inflammatory qualities and therefore may be an acceptable alternative for NaOCl.

INTRODUCTION: The purpose of this ex vivo study was to assess the effect of two root-end filling materials against Candida (C) Albicans. MATERIALS AND METHODS: ProRoot MTA and CEM Cement were compared immediately and 24 h after mixing, in two different concentrations (50 and 100 mg/mL). A total of 50 culture wells were used and divided into experimental (n=10) and control groups (n=5). Those with no medication served as positive and without C. Albicans served as negative controls. All plates were incubated at 37^°C after 1, 24, and 48hours. At each interval, the presence of C. Albicans was assessed and recorded by an independent observer. In addition to observing turbidity, 0.02 mL of samples from each cell was re-cultured on sabouraud dextrose agar plates to confirm change in fungal growth. The data were evaluated and analyzed using Kruskal-Wallis test. RESULTS: Although all fresh and set samples with experimental concentrations showed fungal growth after 1 h; they demonstrated complete fungicidal activity at 24 and 48-h time intervals. CONCLUSION: Under the conditions of this ex vivo study, CEM cement as well as ProRoot MTA has fungicidal effects against C. Albicans even in concentration of 50 mg/mL and after 24 hours.

INTRODUCTION: Biocompatibility is a desirable feature for root-end filling materials. In this study we aimed to compare a new material called cold ceramic (CC) with intermediate restorative material (IRM) and mineral trioxide aggregate (MTA) using Methyl-tetrazolium bromide (MTT) assay. MATERIALS AND METHODS: The materials were tested in fresh and set states: (n=108). The cytotoxicity was compared using L929 fibroblasts as an indicator; tested materials were eluted with culture medium according to ISO: 109935 standard. Distilled water and culture medium served as positive and negative controls, respectively (n=36). The results were evaluated at 1, 24 hours and 7 days. Data were statistically analyzed by one-way ANOVA for each time interval and material status and t-tests. RESULTS: The cytotoxicity of the tested materials were statistically different at the various time intervals (P<0.001). IRM was the most cytotoxic root-end filling material (P<0.001), MTA demonstrated the least cytotoxicity followed by CC.  CONCLUSION: Despite displaying the greatest cytotoxicity, IRM is approved by the American Food and Drug Administration (FDA). Cold ceramic had significantly lower cytotoxicity compared to IRM, in all but one subgroup. Further investigations are required to assess the clinical applicability of this novel material.

INTRODUCTION: Particle size and distribution can influence the properties of materials. This study analyzed and compared the particle size of Root MTA, calcium hydroxide (CH), and a new endodontic cement called calcium enriched material (CEM). MATERIALS AND METHODS: The particle size of each material was analyzed three times using 0.05 mg of test material with a particle size analyzer. The particle size distribution ranges, the cumulative percentage and the mean of particle sizes were calculated. One-way ANOVA, Tukey, and Chi-square tests were used for statistical analyses. RESULTS: Results demonstrated that the distribution of particles was dissimilar. Particle mean size in the three different materials was not significantly different. However, the cumulative percentage of CH and CEM cement particles size demonstrated significant difference (P<0.05). Among the various particle size distributions, the particle distribution in the size range of ≤30 μm showed significant difference between materials (P<0.05). Interestingly, the smallest range of particle size belonged to CEM cement. CONCLUSION: The high percentage of small particles found in CEM cement provides desirable properties such as effective seal, good setting time and film thickness in addition to favorable flow and adaptability.

Autogenous tooth transplantation (ATT) can be considered when there is a hopeless molar tooth and suitable donor present. This report presents an unconventional case of successful ATT of a third molar replacing the adjacent fractured second molar in a 33 year old woman. This wisdom tooth had completely developed roots. Root-end filling with Calcium Enriched Mixture (CEM) cement was performed in the third molar. The second molar was extracted non-traumatically without any bone removal; the wisdom tooth was immediately transplanted into the recipient socket. No endodontic treatment was carried out either during or after the ATT. At six-month and 2-year clinical examination the patient was asymptomatic; the transplanted tooth was still functional, with no evidence of marginal periodontal pathosis. At the same follow ups, radiographic evaluation illustrated bone regeneration, normal PDL, and absence of external root resorption. Transplantation of mature third molar seems to be a promising method for replacing a lost permanent molar tooth and restoring aesthetics and function.