[Comparison of candidal and bacterial adherence to denture base acrylic resins]

Futura Gen and GC Reline Hard denture chairside reline materials have recently been introduced to the dental market. Although yet to be scientifically proven, these products are claimed to have optimal characteristics. This study aimed to compare the adherence of Candida strains and bacteria to denture base acrylic resins. In this in-vitro experimental study, 24 discs were fabricated of Futura Gen, GC Reline Hard and Meliodent reline acrylic resins. Specimens were inoculated with three Candida strains and Streptococcus mutans at three time points and after staining, their optical absorbance [microbial adhesion and biofilm formation] was calculated using spectrophotometry. Two-way ANOVA and Tukey's HSD test were applied for statistical analysis. Absorbance [optical density]of C. albicans strains on Futura Gen, GC Reline and Meliodent hard reline acrylic resins was 0.022, 0.011 and 0.028 at one hour, 0.057, 0.022 and 0.062 at 24 hours and 0.101, 0.051 and 0.11 at one week, respectively. Absorbance of C. glabrata on the mentioned resins was 0.012, 0.008 and 0.016 at one hour, 0.039, 0.029 and 0.044 at 24 hours and 0.075, 0.068 and 0.081 at one week, respectively. Absorbance of C. dubliniensis on these resins was 0.026, 0.035 and 0.027 at one hour, 0.064, 0.066 and 0.067 at 24 hours and 0.11, 0.12 and 0.13 at one week, respectively. Absorbance of standard strain of S. mutans was 0.027, 0.014 and 0.035 at one hour, 0.064, 0.026 and 0.064 at 24 hours and 0.11, 0.05 and 0.11 at one week, respectively. Candidal and bacterial adhesion to denture base acrylic resins was not significantly different at the understudy time points [P>0.05]. Except for C. dubliniensis, the lowest absorbance belonged to Meliodent. However, absorbance increased over time. Optical absorbance of S. mutans was lower in Meliodent. Among yeast strains, the highest absorbance belonged to C. dubliniensis

Knowledge, attitude and practice of pharmacists and health-care workers regarding oral contraceptives correct usage, side-effects and contraindications

Despite the success of the Iranian family planning programme, the number of unwanted pregnancies remains high. To investigate whether health workers in Tabriz are providing correct information and counselling about OCP use, the current study was planned to examine the level of knowledge, attitude and practice of OCP providers. A sample of 150 health-care workers in health houses and 150 community/hospital pharmacists answered a questionnaire about knowledge of correct use of OCP, side-effects, contraindications, danger signs/symptoms and non-contraceptive benefits, and whether they counselled patients about these subjects. Knowledge of pharmacists and health workers was not as high as expected and in many topics they were counselling patients even when they had incorrect knowledge and in other areas they were not providing information to patients despite having the correct knowledge. Better continuing education for OCP providers and especially for pharmacists seems necessary

Production of functional cooked sausage by mentha piperita essential oil as a natural antioxidant and antimicrobial material

Natural antioxidants with plant origin are incorporated to foods in the forms of essential oils or extracts. They can retard lipid oxidation and control spoilage bacteria in foodstuffs [e.g. meat products]. This work was aimed to evaluate the effect of nitrite partial replacement with Mentha piperita essential oil [MPEO] on oxidative, microbial and sensory properties of cooked sausage. GC/MS was used for the identification of essential oil components. Nitrite content [120 ppm] was reduced and replaced with 20, 40 and 60 ppm of MPEO. The effect of MPEO on product rancidity was assessed by peroxide and TBARS values in sausage samples. Antimicrobial properties of the essential oil were evaluated by MICs and MBCs determination against Escherichia coli and Clostridium perfringens by microdilution method. Also, the effect of this replacement on the product color stability was evaluated by determination of L*, a* and b* values, Hue angle, and delta E [2-30]. Results indicated that peroxide and TBARS values of sample with 20 ppm of MPEO were significantly lower than samples with 40 and 60 ppm of MPEO and control, at the end of storage period. With respect to color parameters, hue angle of the sample with 60 ppm of MPEO was significantly higher than samples with lower essential oil levels and control after 30 days of storage. Moreover, total color difference of sample with 60 ppm of MPEO was lower than other samples and control [p<0.05]. Antimicrobial activity of MPEO against Escherichia coli determined as MICs and MBCs were 0.226 and 0.453 mg/ml, respectively. These values turned out as 0.453 and 0.906 mg/ml against Clostridium perfringens. all samples with different essential oil levels were acceptable after 30 days of storage according to PV and TBARS thresholds determined in literature. Replacement of 50% of nitrite with MPEO is a reasonable approach in order to put down harmful effects of nitrite in sausage and to enhance functionality of the product

Correlation between leptin and chronic periodontitis

One important function of leptin is the regulation of immune or inflammatory responses. Moreover, in a recent study no correlation between leptin and periodontal diseases was found. Therefore the aim of this study is to determine the correlation between leptin concentration and chronic periodontitis. In this analytical study, 20 healthy gingival tissue samples [control group] and 20 gingival tissues with advanced and moderate chronic periodontitis [case group] and 20 blood samples were taken from 20 patients. Patients were consisted of 55% females and 45% males with average age of 42.25 yrs. Tissue samples were cultured for 72 hours. In the case of blood samples, the serum was immediately collected. Then ELISA was used for detecting of leptin and IL-6 in supernatant fluids of explant cultures and leptin in serum samples. Statistical analysis was made by Paired T-test and Wilcoxon signed Ranks test. There was no leptin in gingival samples of both cases and control groups. The mean concentration of IL-6 in control and case groups was 81.08 +/- 36.72 and 90.35 +/- 29.71 pg/ml, respectively. Statistical analysis has shown no difference between case and control groups regarding IL-6 concentration. It is concluded that leptin does not have any role as an inflammatory protein in chronic periodontitis and regarding the absence of leptin in all of gingival samples, we could not consider gingiva as a possible source of leptin

[Antibacterial activity of essential oils from Artemisia and Cumin plants against Staphylococcus aureus, Escherichia coli and Vibrio cholera]

The emergence of resistance among bacteria makes it necessary to continuously quest for new antimicrobial agents. The present study was performed to evaluate the antibacterial activity of essential oils from Artemisia and Cumin plants. This was an experimental study carried out at the School of Medicine of Tarbiat Modares University [Tehran, Iran] in 2005. Essential oils of Cuminum cyminum, Bunium persicum seeds and aerial parts of Artemisia turcomanica were prepared by hydrodistillation method. Essential oils of A. khorassanica, A. ciniformis, and A. kopetdaghensis were previously obtained and described. The activities of essential oils were evaluated against a clinical isolate of Vibrio cholerae [isolated during the recent outbreak of cholera in Iran], Escherichia coli ATCC25922, a clinical isolate of Staphylococcus aureus, and Staphylococcus aureus ATCC25923 using disc diffusion assay and broth microdilution method for determination of MIC. The components of oils were identified by Gas chromatography coupled with mass spectrometry. Essential oils showed an acceptable level of antibacterial activities. A. khorassanica and A. turcomanica oils demonstrated the highest activity [inhibition zone: 60 mm] followed by A. ciniformis, A. kopetdaghensis, C. cyminum, and B. persicum, respectively. The major constituent in A. turcomanica oil was camphor and that of Cuminum cyminum and Bunium persicum oils was cuminaldehyde. The results of the present study suggested the effects of essential oils against the tested bacteria in vitro, may contribute to the in vivo efficacy of these oils

Relationship of salivary RANKL and OPG with periodontal disease in type diabetic patients

The alterations of the RANKL/OPG system and the relationship between diabetes and periodontitis have been implicated in several studies. This study aimed to evaluate the relationship between salivary RANKL and OPG concentration and periodontitis in patients with type 1 diabetes. Upon obtaining un-stimulated whole saliva samples from 50 volunteers including 27 type 1 diabetic patients, of whom 12 had periodontitis and 23 systemically healthy subjects, clinical periodontal measurements were recorded. Statistical analysis was performed using Kruskal-Wallis, Mann-Whitney U test and Spearman correlations. Although lowest RANKL and OPG concentration and their relative ratio were observed in diabetic patients without periodontitis, there was no significant difference in RANKL and OPG concentration and RANKL/OPG ratio between the four groups of the study, but OPG concentration and RANKL/OPG ratio correlated positively with the duration of diabetes [p<0.05]. In comparison of the two groups of diabetic patients [with or without periodontitis], there was a significant difference in OPG concentration [p<0.05]. There was also a positive correlation between CAL and RANKL concentration [p<0.01] and RANKL/OPG ratio [p<0.05] in diabetic patients with periodontitis. Based on the limitation of the study, it seems that OPG level and OPG/RANKL ratio may serve as indicators of periodontal destruction in type 1 diabetes

Correlation -IL17A and RANKL concentration in GCF with periodontal disease

Periodontal diseases consist of chronic inflammation in periodontal tissues that induced by periodontophathic bacteria and develop by host immune responses. Several studies reported that IL-17 and RANKL are important in autoimmune diseases, inflammation and bone resorption. Since the exact role of them remains unknown, so the aim of this study was to evaluate the relationship between IL-17A or RANKL concentrations and periodontal diseases. In this analytical and case control study; GCF samples were collected from forty patients with gingivitis and moderate to advanced chronic periodontitis referred to the periodontics clinic of Shahid Beheshti University of medical sciences. IL-17A and RANKL were assayed by enzyme-linked immunosorbent assay. The differences of IL-17 and RANKL concentration analyzed between gingivitis and periodontitis, by Mann-Whitney U- test. The protein level of IL-17A was significantly higher in periodontitis group, while there was not any significant difference regarding RANKL concentration. The elevated level of IL-17A in periodontitis suggests that IL-17A might be an important cytokine in pathogenesis of periodontal disease, which presumably exerts its effect independent of RANKL. Correlations between concentration IL-17A with PD and CAL amplify the role of IL-17A in periodontal tissue destruction

influence of active transport systems on morphine -6-ghicuronide transport in MDCKII and MDCK-PGP cells

Morphine-6-glucuronide [M6G] is a potent metabolite of morphine which has high penetration into the brain despite its high polarity, which could be the result of an active transport system involved in M6G transport through blood brain barrier. Examples of such transporters are p-glycoprotein [POP], probenecid-sensitive transport mechanism, multidrug resistance related protein 1-3, the organic anion transporter family, and the organic anion transporter polypeptide family. The aim of present study was to elucidate the mechanisms involved in transporting morphine's potent metabolite, M6G. M6G permeability via two cell lines; MDCKII and MDCK-PGP, was compared with that of sucrose. M6G transport was examined in different concentrations and in the presence-of inhibitors of different transport systems such as cyclosporine, digoxin and probenecid. M6G concentration was measured using ELISA assay. The method was sensitive, reliable and reproducible. The results confirmed that M6G could cross a layer of MDCK II or MDR-PGP cells more than sucrose could. It was also observed that M6G is a PGP transporter substrate. Its permeability was increased by the use of a PGP expressed cell line, and also in the presence of a strong PGP inhibitor. Digoxin related transporters such as Oatp2 may also involved in transport of M6G. M6G seemed to be a glucose transporter 1 substrate, but was not a substrate to probenecid sensitive transporters. It is concluded that different transporters are responsible for M6G transports via different membrane, which could have effects on its pharmacokinetics or pharmacodynamics

Hyperimmune lipopolysaccharide antiserum mediated inhibition of the adherence of E. coli O157:H7 to HEP-2 cells and large intestine of mice

Escherichia coli O157:H7 is found in cattle farms and can live in the intestine of healthy cattle. Most cases of human illnesses including nonbloody diarrhea, hemorrhagic colitis and hemolytic uremic syndrome can be traced, either directly or indirectly, to cattle. One strategy for reducing the risk of Enterohemorrhagic Escherichia coli [EHEC] infections in human is to reduce the prevalence of infection in cattle. Antiserum against whole cell of isolated E. coli O157:H7 from cattle showed inhibition of adherence of this strain to HEP-2 cells in 1:1280 titer and to intestine tissue of mice in 1:640 titer are significant. histology of intestine tissue confirms our results. The difference between in vivo and in vitro titrations for blocking the attachments depends on these two different conditions

Effects of nanofilms packaging on organoleptic and microbial properties of bread

Thirty percent of agricultural products are annually wasted in Iran, 7 to 8 percent of which are due to improper packaging. In this study, the effects of seven types of nanofilms with low a permeability to oxygen and water vapor on organoleptic and microbial properties of bread were investigated. Voluminous [i.e., non-flat] bread samples packaged in nanofilms were stored at 5°C, 20°C and 35°C and tested for organoleptic properties on days 1, 3, 5, 7, 14, and 21of storage. Also microbial counts in the samples kept at the 3 temperatures were made on day 14. The three main factors affecting significantly staling of the bread samples were type of nanofilm, temperature, and length of storage. The effects of combination of each 2 factors were also statistically significant [p<0.01 and 0.05]. The lowest and highest amounts of staling on day 14 occurred in bread packaged in a 3% composite film [500ppm silver and 450ppm clay] and in the control package sample [with no nano-particles], respectively. The total microbial count decreased with increasing silver nano content of the film, such that the 2% [1000ppm] silver film had the lowest count. In addition, the control packaging at the 3 storage temperatures showed the highest counts for coliform and moulds. The lowest and highest counts for coliform and moulds were found in nano-packaging samples kept at 5°C and 35°C, respectively. In conclusion, the nano composite film with 3% nano-particles [SC3] was judged to be the best film due to lower cost and longer conservation of bread freshness

Cytotoxicity of resin-based cleansers: an in vitro study

Cell culture has been used to study the cytotoxicity of denture base resins. Indeed, denture cleansers and their effects on the resin cytotoxicity need deep concern. The aim of the present in vitro study was to investigate the cytotoxic effect of a heat cured denture base resin treated with two denture cleansers on mouse L-929 fibroblasts. Under aseptic conditions, sample disks of a heat treated resin were prepared, following manufacturers' instruction and divided into 12 groups of ten as follows: I] soaking in 1% sodium hypochlorite, II] soaking in alkaline peroxide solution, and III] soaking in water bath for 1, 24, 72 hours and a week. Suspensions of the fibroblasts with acrylic disks were put in 24-well culture plates, and the culture media containing RPMI-1640 environment plus antibiotics and 10% fetal bovine serum were added. After incubation of the plates at considered time intervals, cytotoxicity of the resin was carried out by MTT assay. A significant difference was noticed for solutions in relation to the biocompatibility of the acrylic resin samples at determined time intervals. The cleansers' soaking samples showed higher cytotoxicity in comparison to those immersed in water at each time interval. The difference between cytotoxic effects of the samples immersed in water or cleansers were significant after 72 hours and one week. Overnight immersion in alkaline peroxide and 1% hypochlorite solutions increased the cytotoxicity of the heat cured acrylic resin, but water storage improved the biocompatibility of the material tested

[Molecular and serological detection of enterotoxigenic staphylococcus aureus from traditionally dairy products]

Staphylococcus aureus is one of the most causes of food poisoning [FP] in dairy products. The main etiologic agent of FP is staphylococcal enterotoxins [SE]. There are different types of SE, but type A [SEA] and type B [SEB] are the most important types. Because traditional dairy products are still produced and sold without a permit from the Ministry of Health, this study was conducted to evaluate molecular and serological detection of enterotoxigenic Staphylococcus aureus SEA and SEB from traditionally dairy products. In the current study, 100 samples of dairy products, which were produced by traditional methods, were transported to the laboratory under sterile conditions and were assessed. Samples were cultured and identified by routine bacteriological methods. The isolated bacteria were evaluated by PCR tests for diagnosis of the gene encoding of SEA and SEB. Subsequently, the ability of above mentioned strains to produce enterotoxin were examined by Sac's culture method and were confirmed by SRID. Data were analyzed using chi-square test. The results indicated that 32% of dairy products were contaminated by Staphylococcus aureus [18% cream, 10% cheese, 4% milk]. The PCR results showed that 15.6% of Staphylococcus aureus isolates possessed the SEA gene, 9.3% had the SEB gene and 6.2% possessed both genes. The ability of enterotoxin production indicated that 80% of SEA and 33% of SEB genes were expressed. Enterotoxins SEA and SEB are heat stable; therefore heating has no effect on dairy products contaminated by entertoxins and gastritis may occur in a short period of time. As PCR is a rapid, sensitive, specific and inexpensive methods, we suggest that it can be replaced to traditionally assays for detecting SE

[Evaluation and comparison of antibacterial effects of alcoholic extracts of zataria multiflora boiss leaves, flowers and root on methicillin-resistant staphylococcus aureus]

Due to increasing drug resistance among pathogenic bacteria toward current and new generation antibiotics, researchers have been investigating to find herbal antimicrobial agents as alternative medicines. In this study, the inhibitory effects of alcoholic extract of Zataria multiflora Boiss leaves, flowers and root on methicillin-resistant Staphylococcus aureus was evaluated and compared. 50 grams of dried thyme leaves, flowers and root were added to 250 ml hydroethanol separately, and were then distilled. The antibacterial properties of the extracts were assessed by Broth Dilution Method and after determining dried weights of the extracts per ml, Minimum Inhibitory Concentration [MIC] and Minimum Bactericidal Concentration [MBC] of them were obtained. Finally, by using Thin Layer Chromatography [TLC], effective compounds of the extracts were detected. Thyme leaves alcoholic extract at 3/031 mg/ml and 6/062 mg/ml concentration, flowers alcoholic extract at 5/687 mg/ml and 11/375 mg/ml concentration and root alcoholic extract at 5/437 mg/ml and 10/875 mg/ml concentration, in order, were able to inhibit and kill all the strains and no difference were observed between them. Analysis of the chromatograms showed that thymol and carvacrol are the main compounds of this herb. However clinical application of herbal extracts and oils sounds valuable because of their less side effects in comparison with current drugs, in order to clinically use thyme alcoholic extracts, further investigations must be done in clarifying the mechanism of action of its effective compounds on microbial agents

[Relation between quinolones and beta-lactams resistance with feature of producing capsules in pseudomonas aeruginosa isolated from urine]

Pseudomonas aeruginosa as an opportunistic pathogen is the most important infectious agent in hospital and has resistance to the common antibiotics. In this study, susceptibility of pseudomonas aeruginosa to quinolones and beta-lactams, and also relation of bacterial capsule and antibiotic resistance were assessed. In this experimental study, 100 strains of pseudomonas aeruginosa from Imam Khomeini hospital were collected and its susceptibility to some of quinolones and beta lactams was determined on the basis of the minimum inhibitory concentration on agar. In order to detection mucoid and non-mucoid strain, capsule was detected by India- ink staining and alginate precipitation methods, and then relation of bacterial capsule and antibiotic resistance was evaluated. MIC method demonstrated 90% susceptibility to ofloxacin, 89% to ciprofloxacin, 59% to nalidixic acid, 43% to ceftizoxime and 39% to ceftriaxone. The susceptibility of these strains was also examined on the basis of disk diffusion agar on moler Hinton medium, and susceptibility to used antibiotics was as following: co-amoxiclave 0%, ceftizoxime 23%, ceftriaxone 29%, carbenicillin 48%, nalidixic acid 50%, Ticarecillin 53%, Ciprofloxacin 36%, ofloxacin 70% and norfloxacin 89%. All strains had alginate capsule and only diameter of capsules was different between strains. This study showed that the method of disc diffusion has less accuracy compared to MIC in determining susceptibility to antibiotics

[Relationship between Interleukin 4 and 12 and chronic periapical lesion size]

Chronic dental periapical lesions resulted from chronic inflammatory response to the periapical tissues. Since T-helper [CD4+Y] cells are the prominent cells in these lesions, so the aim of this study was to determine the correlation between the concentration of IL-4 and IL- 12 [most important cytokines for differentiation of T helper 2 and T helper 1 cells, respectively], and the diameter of chronic periapical lesions. Thirty-eight chronic periapical lesions were collected which 18 periapical lesions had diameter of >/= 5 millimeter [case group] and 20 periapical lesions had the diameter <5 millimeter [control group]. Tissue samples were cultured for 72 hours, then ELISA [Enzyme linked immuno-sorbent Assay] was used for determining the concentration of IL-4 and IL- 12 in supernatant fluids. Mann-whitney U and Spearman correlation tests were used to analyze the data. IL-4 and IL- 12 were found in all of samples. There was no significant difference between case and control groups regarding the concentration of IL-4, IL- 12 and IL-4/IL- 12. The only significant correlation was between IL-4 and IL-6 concentration without any regard to the diameter of lesions [P<0.001] [Spearman correlation coefficient=0.593]. It is concluded that in chronic periapical lesions, probably T helper 1 and T helper 2 cells participate in active phases of inflammation and tissue damage equally. This could be resulted from mixed population of bacteria in these lesions

Possible effect of Chlamydophila pneumoniae on COPD exacerbation

Chlamydophila pneumoniae is one of the common causative agents of respiratory infections. The present study aims to find the role of Chlamydophila pneumoniae infection in infectious exacerbation of chronic obstructive pulmonary disease [COPD] Sixty-five nasopharyngeal swab specimens of COPD patients were studied using fluorescent antibody staining with chlamydia specific conjugated antibody and with fluorescent microscopes. Data were analyzed by using SPSS software, version 13. A total of 65 COPD patients [as defined by the American Thoracic Society], 53 [81.5%] males and 12 [18.5%] females were included in the study. Forty-six [70.7%] subjects had exacerbated COPD while 19 [29.3%] were stable COPD patients. We found 4 positive cases of chlamydophila infection [6.15%], 3 of which [2 men and 1 woman] belonged to the exacerbation group and 1 had stable COPD. Data analysis revealed that there was no significant correlation between chlamydophila infection and COPD exacerbation

[Effect of black pepper, red pepper and zataria multiflora boiss. alcoholic extracts on growth and DNase activity of staphylococcus aureus]

Staphylococcus aureus is one of the most frequently identified pathogens in clinical laboratories and DNase is its important virulence factor. This enzyme is capable of destroying deoxyribonucleic acid [Willett etal., 1988]. There are lots of antibacterial agents that can prevent the production of this enzyme. Staphylococcus aureus can develop drug resistance to many chemical drugs so; considerable effort has been expanded by investigators in the development of herbal drugs. Black pepper, Red pepper and Zataria multiflora Boiss. are some herbal drugs that have been used in cure of infections. In this study, the alcoholic extract of Black pepper, Red pepper and Zataria multiflora Boiss. was tested for antibacterial activity against Staphylococcus aureus. Black pepper, Red pepper and Zataria multiflora Boiss. were provided from Iranian agricultural researches center.2gr of each plant powder was added tolOcc ethanol 96°. After 24hours, the crude extract was separated as an alcoholic extract and concentrated by distillation method. The antibacterial activity against Staphylococcus aureus was examined and the results showed that all the extracts were effective. The extracts that showed antimicrobial activity were later tested to determine the Minimum Inhibitory Dilution [MID] for Staphylococcus aureus. They were also effective on the inhibition of DNase activity. The inhibition against DNase activity was observed at the dilutions lower than the minimum inhibitory dilution [MID] of each extract. The results of this study showed that Black pepper, Red pepper and Zataria multiflora Boiss. extracts can play a significant role in inhibition of Staphylococcus aureus and they can inhibit release of the DNase enzyme

Comparison of cytotoxic and inflammatory effect of four bonding agents on L929 mouse tlbroblasts

It is of interest in restorative dentistry to maintain the pulp vitality after pulp exposure in traumatized teeth or during cavity preparation. If the tooth is asymptomatic, the exposure site is taken place in a saliva-free environment, direct pulp capping is recommended. Pulp capping agents must be biocompatible. The aim of this study was to compare the cytotoxic and inflammatory effects of four bonding agents on L929 fibroblast. In this experimental study, after culturing and passaging these cells, samples of i Bond, Excite, One Step Plus and SE Bond, were prepared in capillary tubes and inserted in cultures. Cytotoxic effects were determined after 1, 24 hours and 7 days by MTT assay and for detecting the IL-6, fibroblast culture media were collected after 24 hours and assessed by ELISA. Statistical analyses were made using Kruskal-wallis and Mann -whitney U tests. There was a significant difference of cytotoxicity among the groups after 1 and 24 hours [P=0.001, P=0.029 respectively]. However, no significant difference was found. After 7 days, the amount of IL-6 production showed no significant difference among the groups. It was determined that i Bond had the least cytotoxic effects among the other groups. However, all the groups could induce the IL-6 secretion from fibroblasts

[ survey of the microleakage of mineral trioxide aggregate, root mineral trioxide aggregate and portland cement in repairing lateral perforations of the root canals]

Perforation is one of the most important problems which may occur during root canal therapy. To repair the perforation and to cut the relation of the root with the tissue of its peripheral environment, materials with adequate sealing ability and suitable price are needed. The aim of this study was to survey the microleakage of the three materials in the restoration of lateral perforations in the roots of the teeth. In this experimental study, 54 intact molar teeth were selected and assigned randomly to three groups. Canals were prepared with stepback technique and perforations were made at the apical third of the roots. The cavities were restored with MTA, Root MTA and Portland Cements type ?. The positive control group was subjected to perforation but no perforations were made in the negative control group. The teeth were covered with two layers of nail varnish restoring in 2% fushin solution for 24 hours after incubation. The teeth were sectioned and their leakage was measured by stereomicroscope. The records were analyzed by one- way ANOVA and LSD [Least Square Differences] test. In the positive group dye was completely entered in all perforation areas while no leakage was observed in the negative group. The statistical test showed no significant difference between MTA and Root MTA groups in terms of leakage [p>0.05]. But MTA and Root MTA had significant differences with Portland cement [p<0.0001]. Considering the results of this study, Root MTA may be considered as a substitute for Pro Root MTA in root canal treatment; however, using Portland type I cement needs more investigations

[Comparison of cellular toxicity of Iranian and non-Iranian self cure acryl and their effects on production of mouse IL-6 by L929 gingival fibroblasts]

Despite the various methods used to initiate the polymerization of resin, the conversion of monomers to polymers is not complete and some unreacted monomers are left in the polymer that is leachable into saliva. Substance leached from resin can cause adverse reactions in the oral mucosa adjacent to the denture. The aim of this study was the comparison of cellular toxicity of Iranian and non Iranian self cure acryl on mouse L929 gingival fibroblasts. Three types of acryl including Trim acryl [poly vinyl Ethyl Methacrylate], Duralay acryl [poly methyl Methacrylate] and Acropars acryl [poly methyl methacrylate] were used. A total of 90 rings [30 for each type] with predetermined sizes were prepared. Suspension of fibroblasts with acrylic rings was put in 24-wells culture plates and a culture media containing RPMI-1640 environment plus antibiotics and 10% FBS were added. The plates were incubated in the Co2 incubator and after one hour, 24 hours and seven days they were checked for cytotoxicity by MTT test and secretion of IL-6 by ELISA technique. Two-way ANOVA, Kruskal-wallis and Mann-Whitney U tests were used for data analysis. Significant differences were found in the biocompatibility of experimental acryl, Trim and Duralay [p<0.05] Acropars and Duralay [p<0.01] and Acropars and Trim [p<0.001], among studied time intervals. No statistically significant difference was seen in the production of IL-6 among these acryl [p=0.120]. Least cytotoxicity was seen at interval of 24 hours with significant statistically difference between one hour and one week time intervals [p<0.001]. This study showed that the acryl having methyl methacrylate [Acropars and duralay] have greater toxic effects on fibroblasts; although the toxic effects of Acropars were more than Duralay. The least cytotoxicity was seen in Trim which has vinylethyl methacrylate. There was no difference among studied acryl on induction of IL-6