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Background and Aim: Osteoblasts and periodontal ligament cells play a major role in wound healing after root end resection. The interaction of osteoblasts with filling materials is critical in healing of surgical lesions. The aim of this study was to evaluate the morphology and adhesion of human osteoblasts (MG-63 cell line) in contact with IRM, gray MTA, white MTA and Portland cement (PC) as root end filling materials.Materials and Methods: In this in vitro study, human osteoblasts of osteosarcoma were provided from the cell bank of Iran Pasteur Institute, and cultured in RPMI 1640 medium. Test materials were mixed according to the manufacturer's instructions and placed in contact with osteoblast cells. After the first, third and seventh days discs of materials with grown cells were fixed and examined by scanning electron microscopy.Results: Results showed that after 7 days most of the osteoblasts were attached to the surface of both gray and white MTA and PC and appeared flat or round, however cells adjacent to IRM were round without any adhesion and spread.Conclusion: Based on the results of this study, human osteoblasts have a favorable response to gray and white MTA and Portland cement compared to IRM.

Background and Aim: Furcal perforation has a great impact on prognosis of endodontic treatments, requiring immediate and proper intervention. Gray MTA is applied as material of choice in repairing perforations. The aim of this study was to evaluate the repair of mechanical furcal perforations, histologically using white MTA and Portland cement and compare them with gray MTA. Materials and Methods: In this experimental study, second to fourth mandibular and maxillary premolar teeth of five dogs received endodontic treatment, then the furcation area of the teeth were perforated and repaired as follow: gray MTA in group1, white MTA in group 2, Portland cement in group 3 and cotton pellet in group 4 (control). Animals were controlled for 4 months and sacrificed using an over dosage of sodium thiopental intravenous injection and perfusion of 10% formaldehyde. Chi-square and Fisher exact tests were used to compare hard tissue formation between groups and between each two groups, respectively. Non-parametric Kruskall Wallis and Dunn procedure were also used to compare degree of inflammation among groups and between each two groups, respectively. Results: Gray MTA had more favorable results (90.9% hard tissue formation and only 9.1% severe inflammation) but the difference between gray MTA, white MTA and Portland cement was not statistically significant. Conclusion: The difference between gray MTA, white MTA and Portland cement groups was not statistically significant for degree of inflammation and hard tissue formation. In conclusion both white MTA and Portland cement can be used instead of gray MTA to repair perforations in accordance to esthetic considerations.

Background and Aim: Mechanical preparation of canal is one of the most important stages in root canal therapy. Various kinds of hand or rotary techniques are used for mechanical preparation of canal and each of them has advantages and disadvantages. During canal preparation, extrusion of debris from the apical foramen can result in periapical inflammation and increased pain and edema. The aim of this study was to compare hand instrumentation technique with three rotary systems (Profile, Race, Flex Master) regarding the amount of extruded debris from apical foramen during canal preparation. Materials and Methods: In this experimental in vitro study, one hundred human extracted single rooted mandibular premolars with curvature between 0-10 degrees were selected and divided into four groups of 25 teeth each. All teeth were shortened to 15 mm length by cutting the crown. Group H was prepared by hand step back technique, group P by Profile system, group R by Race system and group F by Flex Master system. For debris collection, vials containing distilled water were used which were weighed before preparation. After the end of canal preparation, vials were completely dried and weighed again. The difference between weights of vials in two stages was the weight of debris extruded from apical foramen. The groups were compared by One-way ANOVA with p

"nAbstract: Endodontic postoperative pain is still one of the major problems for dentists. According to the researches periapical inflammation after RCT is one of the most important factors causing endodontic postoperative pain. Histamine is one of the effective chemical mediators, which produces such inflammation. So, for controlling pains after RCT, the factors reducing inflammation should be found. The aim of this study was to investigate pain control after RCT by drug prophylaxis with antihistamine (asetemizole). 60 patients were divided in 2 groups (30 patients in each group). Group 1 had a capsule of asetemizole (20mg) and the second group had a placebo capsule one hour before RCT. The patients completed the questionnaire after RCT and gave it back on the next session. The evaluated times were 1, 3, 6, 9, 12, 18, 24 and 72 h after RCT. This study indicated that asetemizole was able to reduce the moderate pericemental pain just at the 9 and 12 hours after RCT, and it was not able to reduce the spontaneous pain after RCT significantly on the evaluated times

Statement of Problem: Root canal cleaning is the main purpose of canal instrumentation. Hand instruments leave more debris and smear layer on the root canal walls. The use of automated instruments is helpful in root canal cleaning. Purpose: The aim of this study was comparison of hand NiTi instruments, rotary flexMaster and FKG race instruments in root canal cleaning. Materials and Method: In this interventional and in vitro study, 75 single canal teeth with minimum curve were selected and divided into three groups of 25 teeth in each. The canals were prepared with hand NiTi file, FlexMaster and race instruments using crown down preparation technique, up to size 40. During preparation, the root canals were irrigated with 5m1 of 0 0.50% Naocl solution and at the end of instrumentation with 5 ml of normal saline. After splitting the roots longitudinally, the amount of the debris and smear layers were quantified on the basis of Hulsmann method, using a scanning electron microscope. The data were analyzed by Kruskal wallis test using SPSS statistical software. Results: In general, flexMaster instruments left less debris than FKG race and NiTi hand instruments significantly (p < 0.05). This difference was significant in all three thirds of the canal. FlexMaster instruments left debris with the smallest size in the middle and coronal thirds of the canal but not the apical third. FlexMaster instruments left less smear layers Just in the apical third of the canal significantly. Conclusion: No completely cleaned root canals were found with any of the three instruments. In general, FlexMaster instruments proved to have better canal cleaning in all three third of the root canal significantly. [ABSTRACT FROM AUTHOR]

Gene selection as a problem with high dimensions has drawn considerable attention in machine learning and computational biology over the past decade. In the field of gene selection in cancer datasets, different types of feature selection techniques in terms of strategy (filter, wrapper and embedded) and label information (supervised, unsupervised, and semi-supervised) have been developed. However, using hybrid feature selection can still improve the performance. In this paper, we propose a hybrid feature selection based on filter and wrapper strategies. In the filter-phase, we develop an unsupervised features selection based on non-convex regularized non-negative matrix factorization and structure learning, which we deem NCNMFSL. In the wrapper-phase, for the first time, mushroom reproduction optimization (MRO) is leveraged to obtain the most informative features subset. In this hybrid feature selection method, irrelevant features are filtered-out through NCNMFSL, and most discriminative features are selected by MRO. To show the effectiveness and proficiency of the proposed method, numerical experiments are conducted on Breast, Heart, Colon, Leukemia, Prostate, Tox-171 and GLI-85 benchmark datasets. SVM and decision tree classifiers are leveraged to analyze proposed technique and top accuracy are 0.97, 0.84, 0.98, 0.95, 0.98, 0.87 and 0.85 for Breast, Heart, Colon, Leukemia, Prostate, Tox-171 and GLI-85, respectively. The computational results show the effectiveness of the proposed method in comparison with state-of-art feature selection techniques., Competing Interests: Declaration of competing interest There is no conflict of interest. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Background: Considering the destructive effects of malnutrition on the growth, development, and health of children and the importance of identifying the factors affecting it, the present study aimed to investigate the status of anthropometric indices and their relationship with maternal nutritional literacy and selected socio-economic and demographic variables among children under 5 years old., Methods: This cross-sectional study was conducted on 405 mothers with children under 5 years old in Urmia, Iran. The data collection tool consisted of two parts. The first part was the demographic and socio-economic information of mother and child and the second part was the Evaluation Instrument of Nutrition Literacy on Adults; EINLA., Results: There was statistically significant relationship between maternal nutritional literacy with weight-for-age, height-for-age, and weight-for-height indices; between weight-for-age index with maternal education, gestational weight gain, and mean weight, as well as mean height of the mother; between weight-for-age and weight-for-height indices with child gender, type of milk consumed, status of starting complementary foods, and history of acute respiratory infection, as well as diarrhea; and finally between height-for-age with family income status., Conclusions: It is suggested that mothers with low nutritional literacy, mothers whose gestational weight gain was not normal, children whose family income is low, boy child, children with a history of disease, children who consume powdered milk and children who have not started complementary foods at the right time be given priority when designing and implementing educational interventions to enhance nutritional status and anthropometric indices of children., (© 2022. The Author(s).)

Blood extracts containing platelet products are gaining popularity in promoting healing and pulp regeneration. This study was designed to evaluate the effect of platelet-rich plasma (PRP) and gallium-aluminum-arsenide (GaAlAs) laser on proliferation and differentiation of human dental pulp stem cells (hDPSCs). In this ex vivo study, hDPSCs isolated from impacted mandibular third molars were cultured in Dulbecco's Modified Eagle's medium )DMEM(with 10% fetal bovine serum (FBS). After reaching the desired confluence, the cells were distributed into 4 groups, namely, control, PRP, laser, and PRP+laser for MTT assay and alkaline phosphatase (ALP) test. In the PRP and PRP+laser groups, 10% PRP was added to each well on the plate. In the laser and PRP+laser groups, as for the proliferation test, laser irradiation was carried out for 45 s, while 135 s was designated for ALP test. After 1, 3, and 5 days, cell proliferation and ALP activity were assessed using MTT and ALP colorimetric assay, respectively. Two-way ANOVA was utilized to analyze data. In PRP and PRP+laser groups, cell proliferation and viability increased until day 3 but began to decline afterwards until the 5th day. In the laser group, the increase in proliferation and viability was observed till day 5 which was less than the control group. Laser and control groups exhibited significantly higher cell viability and proliferation than both PRP and PRP+laser groups. ALP activity was more pronounced in PRP+laser, PRP, and laser in descending order; however, all were less than that of the control group. Only in the control group did the ALP activity augment during the 5-day period. Laser irradiation could induce pulp cell proliferation and demonstrated a better performance than PRP in this regard., (© 2021. The Author(s), under exclusive licence to Springer-Verlag London Ltd. part of Springer Nature.)

The aim of this prospective study was to investigate the predictors of choosing mode of delivery (MOD) among Iranian urban women applying the socio-ecological model. In 2015, a convenient sample of 530 pregnant women in urban regions of Urmia, Iran, was recruited to complete a socio-ecological approach-based questionnaire. Then, 1 week after childbirth, the women were followed up by telephone to be asked about their MOD (response rate = 81.88%). Logistic regression analysis showed that the odds of cesarean section (CS) among the women with university education, whose husbands were an employee in a governmental organization, who preferred a private hospital for delivery, and who selected the CS as the preferred MOD during pregnancy were significantly higher than their counterparts. Among all the factors, the socioeconomic status of the families was more influential in predicting the MOD among women. The cognitive factors like fear of childbirth may not be determinants for MOD if women are from privileged families.

The purpose of this prospective, randomized, double-blind, placebo-controlled study was to determine the effect of preoperative oral administration of ibuprofen or dexamethasone on the success rate of inferior alveolar nerve block (IANB) in patients with symptomatic irreversible pulpitis. Seventy-eight patients with irreversible pulpitis were randomly divided into 3 groups (26 per group) and given one of the following at 1 hr prior to performing local anesthesia: a placebo; 400 mg ibuprofen; or 4 mg dexamethasone. Each patient recorded their pain level on a visual analog scale before taking the medication or placebo, at 15 min after completion of IANB, and during treatment if pain occurred. The success of the anesthesia was defined as no or mild pain at any stage during the endodontic procedure. The success rate of the IANB was 38.5, 73.1, and 80.8% with the placebo, ibuprofen, and dexamethasone, respectively. Both ibuprofen and dexamethasone were significantly more effective than the placebo. No significant difference was observed, however, between the two experimental medications in terms of effectiveness. The results of the present study suggest that premedication with ibuprofen or dexamethasone increases the success rate of an IANB in patients with symptomatic irreversible pulpitis in the mandibular molars.

Introduction: The aim of this study was to determine the histologic effect of low level laser therapy (LLLT) with or without the use of mineral trioxide aggregate (MTA) on exposed pulp tissues of dogs. Methods: Twenty-five premolar teeth in three healthy mature dogs were randomly divided into five groups. In group 1, the pulp tissue was capped with MTA. In groups 2 and 3, before capping with MTA, the exposure site was irradiated by low power lasers at 630 nm (20 mW, 150 seconds, 7.5 J/cm 2 ) and 810 nm (peak power 80 W, average power 50 mW, 1500 Hz, 50 seconds, 6.25 J/cm 2 ) wavelengths, respectively. In groups 4 and 5, the exposure site was irradiated similar to that described in groups 2 and 3, but the pulp tissue was covered by gold foil instead of MTA. After 2 months, the animals were sacrificed and the samples were prepared for histologic evaluation. Results: There were differences in pulpal response and dentinal barrier formation among the study groups. The morphology of pulpal tissue and the integrity of dentinal barrier and formation of odontoblastic layer were more favorable in the first three groups. The occurrence of extensive and intense inflammation and necrosis was more frequent in groups 4 and 5. Conclusion: Under the conditions used in this study, the presence of MTA as a pulp capping material was more important than laser therapy in the success of direct pulp capping (DPC) treatment. MTA proved to be an effective material either alone or in combination with laser irradiation in vital pulp therapy.

Background and aims. Substituting chlorhexidine (CHX) for water has been shown to enhance antimicrobial activity of mineral trioxide aggregate (MTA). The purpose of this study was to compare the compressive strength of MTA mixed with distilled water, 0.12% and 0.2% chlorhexidine. Materials and methods. MTA was mixed according to manufacturer's instructions in group I (n = 20). In groups II & III, 0.12% and 0.2% CHX liquid was substituted for water, respectively. Samples were condensed with moderate force into 20 tubes with 1.5×5 mm dimensions and were allowed to set for 72 hours at 37°C in 100% humidity. After being removed from the molds, their compressive strength was determined using Instron testing machine. Each group was divided into two subgroups according to the time of testing (at 72 hours, and one week). Fractured surfaces of 4 specimens in each group were then evaluated under Scanning Electron Microscope (SEM) to determine their microstructure. One-way ANOVA, Tukey, and paired sample t-test was used for statistical analysis. P < 0.05 was set as significant. Results. There was no significant difference between three groups in terms of their compressive strength after 72 hours. However, the compressive strength of group II was significantly higher than group I (P = 0.034) and group III (P = 0.021) after one week. Crystalline microstructure was similar in all groups. Conclusion. Substitution of 0.012% chlorhexidine for water significantly increased the compressive strength of MTA at 1 week without significant change in crystalline structure.

Introduction: Pain or swelling caused by various stages of inflammation/infection of the pulp/periradicular area is among endodontic emergencies. Determining the most effective method of emergency treatment is a challenging issue in endodontics. The goal of this study was to determine and compare the level of knowledge in general dentists and endodontists about endodontic emergency treatment plan in Mashhad, Iran in 2012-2013., Methods and Materials: In this cross-sectional descriptive study, 152 questionnaires were distributed among 120 general dentists and 32 endodontists of Mashhad. The questionnaire contained two separate parts. The first part included demographic information and in the second part different treatment protocols were suggested for 12 various conditions of pulp/periapical emergencies, and the participants were asked to choose the correct option(s). To determine the relationship between qualitative variables, the chi-square analysis was used. The level of significance was set at 0.05., Results: There were significant differences between treatment plans presented by general dentists and endodontists about endodontic emergencies, especially in cases of necrotic pulp and subsequent swelling., Conclusion: Level of knowledge of dentists about the indications of incision and drainage, intra-canal medicament, root filing beyond the apical foramen and antibiotic prescription was not enough. These findings highlight the importance of refreshing courses for general dentists to improve their competency in the management of endodontic emergencies.

Advantages of transcanalicular laser-assisted dacryocystorhinostomy (TCDCR) over conventional, external, and endonasal dacryocystorhinostomy (DCR) have been purported to include decreased operating time, reduced morbidity, enhanced cosmesis, avoidance of general anesthesia, and a shorter recovery time. However, 1 case of skin necrosis has recently been reported to have occurred following diode laser-assisted TCDCR, and the authors now report 3 additional cases that were evaluated by the Ophthalmic Plastic Surgery services at the University of North Carolina, North Carolina, and the University of California, San Francisco. Three patients developed full-thickness tissue necrosis over the medial canthus following TCDCR, and 2 of these patients experienced persistent tissue breakdown at the site following reconstructive repair.

We compared the apical seals of two new calcium silicate-based sealers (iRoot SP and MTA Fillapex) in the presence and absence of a smear layer. Eighty-two human premolars were prepared and randomly divided into four groups. In groups 1 and 3, the smear layer was retained. In groups 2 and 4, the root canals were irrigated with EDTA to remove the smear layer. Canals were filled using gutta-percha/iRoot SP (in groups 1 and 2) or obturated with gutta-percha/MTA Fillapex (in groups 3 and 4). Fluid filtration was used to evaluate apical microleakage. The presence of the smear layer had no significant effect on the sealing properties of the filling materials, except for iRoot SP at 2 weeks (P = 0.007). There was significantly less microleakage with iRoot SP than with MTA Fillapex (P = 0.025 at 2 weeks; P < 0.001 at 3 months). Leakage decreased significantly over time in all specimens, except in group 2 (P = 0.473). In conclusion, removal of the smear layer had no adverse effect on the sealing properties of calcium silicate-based sealers. In addition, the sealing ability of iRoot SP was superior to that of MTA Fillapex.

Background and aims. Mineral trioxide aggregate and calcium hydroxide are considered the gold standard pulp-capping materials. Recently, Portland cement has been introduced with properties similar to those of mineral trioxide aggregate. Histopathological effects of direct pulp capping using mineral trioxide aggregate and Portland cements on dog dental pulp tissue were evaluated in the present study. Materials and methods. This histopatological study was carried out on 64 dog premolars. First, the pulp was exposed with a sterile bur. Then, the exposed pulp was capped with white or gray mineral trioxide aggregates and white or gray Portland cements in each quadrant and sealed with glass-ionomer. The specimens were evaluated under a light microscope after 6 months. Statistical analysis was carried out using Kruskal-Wallis test. Statistical significance was defined at α=5%. Results. There was no acute inflammation in any of the specimens. Chronic inflammation in white and gray mineral trioxide aggregates and white and gray Portland cements was reported to be 45.5%, 27.3%, 57.1% and 34.1%, respectively. Although the differences were not statistically significant, severe inflammation was observed mostly adjacent to white mineral trioxide aggregate. The largest extent of increased vascularization (45%) and the least increase in fibrous tissue were observed adjacent to white mineral trioxide aggregate, with no significant differences. In addition, the least calcified tissue formed adjacent to white mineral trioxide aggregate, although the difference was not significant. Conclusion. The materials used in this study were equally effective as pulp protection materials following direct pulp capping in dog teeth.

Background and aims. It is important to evaluate the effects of endodontic materials on tooth structures to avoid endodontic treatment failure. The aim of the present study was to investigate the effect of mineral trioxide aggregates (MTA) and Portland cement (PC) on fracture resistance of dentin. Materials and methods. Thirty-six freshly extracted human single-rooted premolar teeth were selected. The crowns were removed and the roots were randomly divided into two experimental groups and one control group. The root samples were longitudinally divided into two halves and a dentin bar (2×2×10 mm) was cut from each root section for short-term (2weeks) and long-term (12 weeks) evaluations. The root sections in the experimental groups were exposed to MTA or PC, while keeping the control group specimens in physiologic saline. The fracture resistance of each specimen was measured using an Instron testing machine. The results were statistically analyzed using ANOVA, a post hoc Tukey test and paired t-test at 5% significance level. Results. The fracture resistance of MTA-treated specimens significantly increased between 2 and 12 weeks (P<0.05). After 12 weeks, MTA-treated specimens had the highest fracture resistance. In the PC group, the fracture resistance of specimens did not change significantly over time (P>0.05). Conclusion. The results showed that MTA increased the fracture resistance of root dentin, while PC had no significant effect on dentin fracture resistance.

Background: This study was to evaluate the effects of calcium hydroxide premedication on the marginal adaptation of the calcium-enriched mixture (CEM) cement as an apical plug., Materials and Methods: In this in vitro study, forty single rooted teeth were prepared and apical portion of the roots were immersed in sulfuric acid to produce open apices. The teeth were divided into 2 experimental groups. In medicated group, calcium hydroxide was placed in all canals for 1 week and in non-medicated group no dressing was used. Then, a 4-mm apical plug of CEM cement was placed in canals; each root was prepared for observation using scanning electron microscope and the maximum distance between CEM cement and surrounding dentin was measured. The data were analyzed by t-test, and significance level was set at α = 0.05., Results: The mean width of gap in medicated and non-medicated groups was 158/1 μm and 147/1 μm, respectively. There was no significant difference between the two groups (P > 0.05)., Conclusion: Calcium hydroxide premedication had no adverse effect on the marginal adaptation of CEM cement apical plug.

Objective: To describe the complication of anterior filler displacement following injection of calcium hydroxylapatite gel (Radiesse) for anophthalmic enophthalmos correction., Methods: Retrospective case series of patients who experienced anterior filler displacement following orbital injection of calcium hydroxylapatite. Data includes patient demographics, indication for injection, route and volume of injection, description of postinjection complications, and final outcome., Results: Four cases of anterior filler displacement and expansion following injection of calcium hydroxylapatite were identified. The patients' ages ranged from 33 to 64 years old. All 4 patients underwent multiple prior orbital surgeries and suffered from anophthalmic enophthalmos. Injectable calcium hydroxylapatite was delivered transcutaneously, to the deep extraconal orbital space, via 27-gauge, 1.25-inch retrobulbar needles. Each patient received an initial 1.3 ml of filler, with 1 patient receiving an additional 0.8 ml. Within 1 week, all patients experienced prominent, edematous lower eyelids. A CT scan of 1 patient radiographically documented anterior migration of the filler material. Two patients required transconjunctival excision of the filler and infiltrated orbital fat. Histopathologic examination of 1 specimen revealed chronic foreign body granulomatous inflammation. Two patients were treated medically, with resolution of clinical findings over 6 to 9 months., Conclusions: Anterior filler displacement is a potential complication of orbital volume augmentation with injectable calcium hydroxylapatite. Patients should be counseled regarding this possibility when considering options for the treatment of anophthalmic enophthalmos. A history of multiple prior orbital surgeries, with associated tissue disruption and scarring, may be a risk factor for filler displacement.

Aim: To compare the antimicrobial effect of 2% chlorhexidine, 2.5% sodium hypochlorite and MUMS containing 2% chlorhexidine., Materials and Methods: All of the above irrigants were examined on Enterococcus faecalis, Streptococcus mutans, Candida albicans, Lactobacillus casei and E. coli. A total of 0.5 CC of each solution and 0.5 CC of McFarland solution bacterium were added to each examination tube. After 15, 30 and 45 minutes, colony count was performed for each tube. The difference in the number of bacteria indicated the effect taken by disinfectant material., Results: MUMS containing chlorhexidine showed the antimicrobial properties just like chlorhexidine's effect against E. coli, Streptococcus mutans, Candida albicans, Enterococcus faecalis and Lactobacillus casei in preventing these entire microorganisms to incubate. Sodium hypochlorite was not effective against Enterococcus faecalis and Candida albicans incubated in 15, 30 and 45 minutes and Enterococcus faecalis in 15 minutes., Conclusion: MUMS has antimicrobial properties similar to chlorhexidine., Clinical Significance: As MUMS containing chlorhexidine can transfer chlorhexidine through its own surfactant around apical area and it can open the dentinal tubules by its own chelator for more penetration of chlorhexidine, it may be a choice for canal irrigation.

Background: The aim of this study was to evaluate the antimicrobial activity of Mineral Trioxide Aggregate (MTA) and Calcium Enrich Mixture) CEM (mixed with different concentrations of chlorhexidine (CHX)., Materials and Methods: Cements used in this in vitro study included Gray proRoot MTA and CEM with the microorganisms being entrococcus faecalis, streptococcus muntas, Candida albicans, Actinomyces, Escherichia coli, and a mixture of these microorganisms. CHX was used in the form of liquid at 0.2%, 2%, and 0.12% concentrations. Contact dilution and colony count method was used to evaluate the antibacterial activity of these cements. After 0, 24, 48, 72, and 96-hour intervals, we cultured the samples on blood agar medium. Colonies were counted after incubation at 37°. Data were statistically analyzed by a Kruskal-Wallis test to compare the antimicrobial activity of MTA and CEM., Results: All concentrations of CHX were mixed with MTA and the CEM had antibacterial activities on all microorganisms' strains except for the Enterococcus faecalis and the mixture group. MTA had better antibacterial activity than the CEM, but this difference was not significant (P = 0.13). The mixing of MTA and the CEM with CHX significantly increased the antibacterial properties of both cements (P < 0.03). There was no statistically significant difference between the different concentrations of CHX. The antibacterial activity of the materials increased through time., Conclusion: The mixture of MTA and CEM with different concentration of CHX significantly increased the antibacterial activity.

Introduction: The aim of this study was to evaluate the effects of remnant root canal medicament, calcium hydroxide on the short and long term sealing ability of mineral trioxide aggregate (MTA) apical barrier., Materials and Methods: Fifty single-rooted teeth were prepared and apical resorptions were made using sulfuric acid. The teeth were allocated into two experimental groups and two control groups. In group 1, calcium hydroxide was placed into canals for one week. In group 2, no medication was placed. In both groups, a 4-mm MTA plug was placed in the root canals. The remaining portion of the canal was filled with gutta-percha/sealer. The microleakage was evaluated after 7 days and 3 months using fluid filtration technique. Repeated measurement ANOVA was used for statistical analysis., Results: There was no significant difference in sealing ability between the two groups in either time periods. In both groups, microleakage decreased after three months but this decrease was not statistically significant., Conclusion: Medication with calcium hydroxide had no adverse effect on the short and long-term sealing properties of MTA plug.

Objectives: Using the fluid filtration method, an in vitro study was conducted to evaluate the effects of medication with calcium hydroxide on the sealing ability of the New Endodontic Cement (NEC) apical barrier in the short and long terms., Methods: Fifty extracted single rooted teeth were prepared and apical resorption produced using acid sulfuric for four days. The teeth were randomly divided into two experimental groups (n=20) and two control groups. In group 1, calcium hydroxide was placed into all canals for one week and in group 2, no medication was used. In both groups, a 4 mm NEC apical plug was placed in the canals and the remaining portion of the canals was filled with gutta-percha. The amount of microleakage of all samples was evaluated after one week and three months. The data were statistically analyzed using two-way ANOVA., Results: There was no significant difference between the two groups in either time period (P>.05). In both group 1 and group 2, microleakage increased after three months but this increase was not statistically significant (P>.05)., Conclusions: According to the result of this study, medication with calcium hydroxide had no adverse effect on the short- and long-term sealing properties of an NEC apical plug.

Introduction: The materials used for root-end filling and perforation repair are in direct contact with live tissues e.g. bone and connective tissue; their effects however, are uncertain. The aim of this ex vivostudy was to evaluate the osteoblastic secretory activity adjacent to gray and white mineral trioxide aggregate (MTA) and Intermediate Restorative Material (IRM)., Materials and Methods: The studied materials were prepared and placed in 24-wells plate. Human MG-63 osteoblasts were introduced to materials after their initial set. The supernatant fluid was collected after 1, 3, and 7 days and the level of interleukin-1β was measured by ELISA test. A microscopic exam was also performed to assess proliferation and viability of the cells. Kruskal-Wallis and Tukey tests were used for analysis., Results: T here were significant higher levels of interleukin-1β in the gray and white MTA groups compared to IRM group (P<0.05). The difference in interleukin-1β secretion level between two mineral trioxide aggregate groups was not significant (P>0.05).Morphologic appearance of osteoblasts adjacent to gray and white MTA was similar to normal osteoblasts in all observation periods, however cells adjacent to IRM were round, signifying cytotoxicity of the adjacent material., Conclusion: Human osteoblasts' has a favorable biologic response to white and gray MTA compared to IRM.

Introduction: The purpose of this study was to evaluate the effect of calcium hydroxide premedication on the marginal adaptation of the mineral trioxide aggregate (MTA) apical barrier., Methods: Forty single-rooted teeth were prepared and apically resorbed using sulfuric acid for 4 days. Teeth were allocated into two groups according to whether calcium hydroxide was placed in the canals for 1 week (medicated group) or not (nonmedicated group) before placing a 4-mm MTA apical plug in the canals. The roots were mounted on aluminum stubs, the root apex was viewed from the top under scanning electron microscopy, and the maximum distance between MTA and the surrounding dentin was measured., Results: The mean gap widths in the medicated and nonmedicated groups were 70.2 μm and 130.0 μm, respectively (p < 0.05)., Conclusions: Calcium hydroxide treatment improves marginal adaptation of the MTA apical plug., (Copyright © 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: This study compared the cleaning efficiency of Mtwo, Race and Medin Nickel-Titanium (NiTi) rotary instruments., Materials and Methods: Sixty mandibular molar mesial roots were selected with angle curvatures between 25-35 degrees and divided into three groups; each containing 20 teeth. Canals were prepared with the rotary files and irrigated with 2.5% NaOCl solution after each instrument. Total of 5mL of normal saline was used as the final rinse; subsequently the canals were dried with paper points. The amount of debris and smear layer in three parts of the root canal walls was evaluated using SEM and the data were analyzed by using the Kruskal-Wallis test and the Mann-Whitney U test., Results: The results for remnant debris in the coronal part of root canals were similar, whereas in the middle third, Mtwo instruments achieved significantly better results compared to Race and Medin instruments. In the apical third of the root canals more debris was created by Race instruments., Conclusion: Overall, Mtwo instruments had greater success in producing clean canals.

Introduction: Gutta-percha is the most commonly used material for root canal obturation; it has been recently manufactured with different tapers. The aim of this in vitro study was to compare microleakage of canals obturated with standard gutta-percha (0.02 taper) or the new 0.04 taper gutta-percha master cone using the cold lateral condensation technique., Materials and Methods: Forty-four extracted single rooted teeth were selected. The crowns were removed and all the canals were prepared using RaCe rotary files. The teeth were then divided into experimental (n=2) and control (n=2) groups. In the first study group, the teeth were obturated with 0.02 taper gutta-percha master cone and lateral condensation. In the second study group, the canals were obturated by 0.04 tapered master cones and the same obturation method. The degree of leakage was measured using fluid filtration method. Data were analyzed statistically by student t-test., Results: There was no significant difference between the mean microleakage of two experimental groups (P=0.558)., Conclusion: Lateral condensation technique using 0.04 tapered master cones can provide an effective apical seal similar to 0.02 gutta-percha cones.

Introduction: Open-apex teeth with irreversible pulpitis require complex and difficult treatment. Providing the right environment for apexogenesis and pulp protection is vital for their long term prognosis. The young pulp of open apex tooth, however, is better equipped against irritation and assault. The aim of this study was to evaluate pulp inflammation in open apex canine teeth of cats., Materials and Methods: In this in vivo study, twelve cats with open apex canines were used. Pulps were iatrogenically exposed and the animals were sacrificed at one, seven, thirty and ninety days after pulp exposure. Samples were prepared for histological evaluations., Results: During the first and seventh day, changes were limited to acute inflammation in the coronal pulp. During the first month pulp changes in 45.5% of samples were similar to the seventh day. In the other samples necrosis and abscess spread to the end of the root, and internal resorption and periapical abscess were observed. In 45.5% of samples in the apical region vital tissue was barely observed (during 90 days); in 54.5% of samples however, complete pulp necrosis, internal resorption and a large periapical lesion was observed., Conclusion: In one and seven-day periods pulp tissue was vital, however, in the thirty and ninety-day periods, minority of the pulp samples were vital.

Introduction: Osteoblasts and periodontal ligament cells are major cells for wound healing after root end resection. The interaction of osteoblasts with filling materials could play a critical role in healing of surgical lesion. Adhesion and spreading of cells on material surface are the initial phase for cellular function. The purpose of the present study was the evaluation of morphology and attachment of human osteoblasts in present of white MTA, Portland cement (PC) and IRM as root end filling and perforation repair materials., Materials and Methods: The human osteoblasts (MG-63 cell line) were prepared from Iranian Pasteur Institute; Cellular Bank, were grown in RPMI 1640 medium. The testing materials were mixed according to the manufacture's instruction, inserted in to the wells of 24-well flat-bottomed plate, and condensed to disk of 1mm thickness and 1×1mm diameter. Cells were added to the materials after two weeks. During 1,3,7 days intervals, the disk of materials along with cells were grown on their surface, examined by a scanning electron microscope (SEM). We used of IRM as negative group., Results: Results showed that after 7 days many of osteoblasts were attached on the surface of white MTA and PC and appeared partially round or flat. The cells appeared round with no attachment and spreading in conjunction with IRM., Conclusion: The results indicate that human osteoblasts have a favorable response to white MTA and Portland cement compared with IRM.

The use of a suitable substance that prevents egress of potential contaminants into the periapical tissues is important in endodontic surgery. The aim of the present study was to compare the marginal adaptation of three root-end filling materials (white mineral trioxide aggregate (MTA), grey MTA and Portland cement), using scanning electron microscopy. Seventy-five single-rooted extracted human teeth were used. The canals were instrumented and filled with gutta-percha. Following root-end resection and cavity preparation, root-end cavities were filled with white MTA, grey MTA or Portland cement. Using a diamond saw, roots were longitudinally sectioned into two halves. Under scanning electron microscopy, the gaps between the material and dentinal wall were measured. The data were analysed using Kruskal-Wallis test. The mean of the gap in grey MTA, white MTA and Portland cement was 211.6, 349 and 326.3 microm, respectively. The results indicate that the gap between grey MTA and the dentinal wall is less than other materials, but there was no significant difference between the materials tested in this study (P > 0.05).

Purpose: To characterize the clinical and imaging features of orbital leukemic tumors in 27 patients seen and treated at St. Jude Children's Research Hospital., Methods: A retrospective review was performed on the clinical and imaging records of 27 consecutive patients with a diagnosis of orbital leukemic tumors. The following data were extracted from the patients' records: age at diagnosis of orbital leukemic tumors, sex, race, national origin, type of leukemia, temporal relationship of orbital disease to diagnosis of leukemia, survival from diagnosis of orbital leukemic tumor, laterality of the orbital disease, location of the mass within the orbit, imaging features of the mass, chemotherapeutic protocol, treatment with bone marrow transplant, and orbital radiation., Results: The median age at diagnosis of orbital leukemic tumor was 8 years (range, 1-18 years). Nineteen of the 27 patients were male, and 21 patients were born and lived in the United States. Twenty-one patients had acute myeloid leukemia, five had acute lymphoblastic leukemia, and one had chronic myelogenous leukemia. In 85% of patients (n = 23), the diagnosis of leukemia was based on the bone marrow examination findings. Orbital imaging revealed homogenous masses that molded to one or more orbital walls without bony destruction. Nine patients had bilateral orbital involvement. All patients received multiagent systemic chemotherapy, and 14 underwent bone marrow transplantation. Five patients received external beam radiation for the treatment of orbital disease. Fifteen (55.6%) of the 27 patients were alive at the time of the study. The median survival for all patients was 4.75 years (range, 0.1-24 years) after the diagnosis of orbital disease., Conclusions: Orbital leukemic tumors occur most commonly in the first decade of life, in association with acute myeloid leukemia. They appear as homogenous masses along the orbital walls. Although the overall survival rate for patients with leukemia has improved over the past 3 decades, the mortality of patients who develop orbital leukemic tumors remains high.