Showing 12 results for Bacteria
M. Zarabian , M. Aligholi , N. Shokouhi Nejad ,
Volume 18, Issue 3 (5-2005)
Abstract
Background and Aim: Today several materials have been used for root- end filling in endodontic surgery. Optimal properties of Pro Root MTA in in-vitro and in-vivo studies has been proven. On the other hand, based on some studies, Root MTA (Iranian Pro Root MTA) and Portland cement are similar to Pro Root MTA in physical and biologic properties. The aim of this study was to evaluate bacterial leakage (amount and mean leakage time) of four root- end filling materials.
Materials and Methods: In this experimental in-vitro study, seventy six extracted single- rooted human teeth were randomly divided into six groups for root-end filling with gray Pro Root MTA, white Pro Root MTA, Root MTA (Iranian Pro Root MTA), Portland Cement (type I) and positive and negative control groups. Root canals were instrumented using the step- back technique. Root- end filling materials were placed in 3mm ultra sonic retro preparations. Samples and microleakage model system were sterilized in autoclave. The apical 3-4 mm of the roots were immersed in phenol red with 3% lactose broth culture medium. The coronal access of each specimen was inoculated every 24h with a suspension of Streptococcus sanguis (ATCC 10556). Culture media were observed every 24h for colour change indicating bacterial contamination for 60 days. Statistical analysis was performed using log- rank test with P<0.05 as the limit of significance.
Results: At the end of study 50%, 56.25%, 56.25% and 50% of specimens filled with Gray Pro Root MTA, White Pro Root MTA. Root MTA and Portland Cement (type I) had evidence of leakage respectively. The mean leakage time was 37.19±6.29, 36.44±5.81, 37.69±5.97 and 34.81±6.67 days respectively. Statistical analysis of data showed no significant difference among the leakage (amount and mean leakage time) of the four tested root- end filling materials (P=0.9958).
Conclusion: Based on the results of this study, there were no significant differences in leakage among the four tested groups at 60 days. The results suggest that Root MTA and Portland Cement can be used as less expensive root filling materials.
H. Razmi , M. Aligholi , Sd. Sadeghi ,
Volume 19, Issue 4 (1-2007)
Abstract
Background and Aim: Many studies have shown that microorganisms are the main cause of pulpal diseases and the main purpose of root canal therapy is their elimination from the root canal system. Antiseptic agents are used to reduce bacteria but their antibacterial activities differ from in vivo to in vitro studies and might be inactivated by dentin and its components in root canal space. This study was designed to investigate the effect of dentin on antibacterial activity of different antimicrobial agents.
Materials and Methods: In this experimental study, two antibacterial agents (sodium hypochlorite and chlorhexidine) with different concentrations were used in four experimental groups: Group 1: dentin, Group 2: demineralized dentin with EDTA, Group 3: dentin matrix and Group 4: dentin mineral component. The species used in this study was Entrococcus faecalis. Different concentration of agents were added to mixture of each experimental group and bacteria. At the baseline and after one and 24 hours, samples were collected and cultured. After incubation period, colonies were counted. Data were analyzed by Tukey test with p<0.05 as the limit of significance.
Results: 2% and 0.2% chlorhexidine, and 5% sodium hypochlorite solutions at the three studied times eliminated Entrococcus faecalis completely. 1% sodium hypochlorite eliminated all bacteria in 1h and 24 hs. Statistical analysis showed significant differences between experimental and control groups (P<0.05). Sodium 1% hypochlorite at time 0, could reduce bacteria significantly (P<0.05) but didn’t eliminate them completely.
Conclusion: Inactivation of intracanal antiseptics was not observed in this study. As elimination of bacteria occurred, application of these antibacterial agents are recommended in endodontic treatment. Further investigations on other antibacterial agents, other concentrations and shorter time intervals are recommended.
M. Hashemipour, Mr. Korki,
Volume 21, Issue 3 (12-2008)
Abstract
Background and Aim: Infective endocarditis is a rare disease resulted in mortality and morbidity in 10-80% of patients. The purpose of present study was to investigate the knowledge of guidelines on antibiotic prophylaxis for bacterial endocarditis in a group of Iranian dentists.
Materials and Methods: This was a descriptive study in which the population under study was 205 who were participated in the 47th international congress of dentistry (Tehran-Spring 2007) and they were chosen by census sampling methods. Nameless questionnaires were designed and were given to the dentists to complete. The t-test, χ² and spearman with the SPSS 13.5 program were used in the data analysis. P<0.05 was considered as the level of significance.
Results: Regarding to the prescribing of prophylactic antibiotic for patients with prosthetic cardiac valves, 94.6% of all answers were correct. Also, the most common procedures in which the prophylaxis antibiotic was distinguished to be necessary were periodontal surgery, scaling, dental extraction and using subgingival cord, respectively. More than half of the dentists (65.8%) had chosen amoxicillin as a prophylactic antibiotic. Mean knowledge score was 38.77±12.4.
Conclusion: Results of the present study showed that the knowledge of dentists about prescribing antibiotics for prevention of bacterial endocarditis is relatively low. It was also found that the level of knowledge decreases by passing time from graduation.
F. A. Nakhjavani, Ms. Sheikhrezaie, S. Negahbani,
Volume 21, Issue 3 (12-2008)
Abstract
Background and Aim: Elimination of microorganisms and their byproducts from root canal system is one of important aims of root canal therapy. This object is gained by using of many chemomechanical techniques but with noncertain success. A new method is used of nonpathogenic bacteria for growth inhibition of pathogenic bacteria, Antibiosis, in root canal therapy.The aim of this study was in vitro evaluation of antimicrobial effect of probiotics, such as Lactic Acid Bacteria (LAB) on the infected root canal bacteria.
Materials and Methods: Isolated bacteria from infected root canal were grown and then scattered onto the muller Hinton agar plates which contain wells, LAB, extracted from dairy products, were added into these wells, Inhibition effected of LAB was determined. Furthermore the sample taken from the inhibition zone and possible resistant monoclonal bacteria also were identified, then 6 sensitive and 14 resistant samples were selected and E. faecalis species were added to them Then antimicrobial effects of LAB on these samples was reevaluated.
Results: The results showed that 66.7% of the samples were sensitive at least to one type of LAB, and 33% were resistant to all kind of LAB. Meanwhile the outgrowing anaerobic bacteria inside the inhibition zone were from the low frequency oral bacterial flora. Furthermore, adding E. faecalis to the samples caused more sensitivity of them to LAB. Mc-Neamar test recognized the difference significant.
Conclusion: This study showed that the LAB inhibit growth of the pathogenic root canal bacteriae. Furthermore, presence of E. faecalis reinforces the antimicrobial effect of LAB. It seemed that LAB maybe have potential to use in endodontic practice for elimination of root canal infections.
H. Kermanshah, S. Hashemi Kamangar, S. Arami, A. Mirsalehian, M. Kamalinejad, M. Karimi, F. Jabalamoli,
Volume 22, Issue 2 (11-2009)
Abstract
Background and Aim: The microbial cause of dental caries has been proved among its multifactorial etiologies. The prevention and control of dental caries is very critical because of high prevalence and cost especially in high risk patient such as xerostomia. Based on the world attraction to traditional treatment and importance of drug extraction of natural materials and plants, in this in vitro study effect of hydroalcoholic extract of Salvia officinalis and Pimpinella anisum which were very useful in traditional treatment of mouth and teeth disease has been determined against cariogenic bacteria.
Materials and Methods: In this experimental study, hydroalcoholic extracts have been prepared from Salvia officinalis and Pimpinella anisum with maceration method. Their antibacterial activity against Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus have been evaluated with broth macrodilution method. Data were analyzed with Mann-Whitney test.
Results: Minimum Inhibitory Concentration for Salvia officinalis and Pimpinella anisum for streptococcus mutans were respectively 6.25 and 12.5 µg/ml, for Lactobacillus rhamnosus were 1.56 and 12.5 µg/ml and for Actinomyces viscosus were 12.5 and 50 µg/ml.
Conclusion:Both extracts had growth inhibitory effect on all three bacteria. Salvia officinalis had significantly greater effect on inhibition of growth of all three bacteria. Both extracts had bactericidal effect in the range of concentration.
Abbas Ali Jafari, Mohamad Hosein Lotfi Kamran, Abbas Falah Tafti, Esmaiel Kheirkhah,
Volume 25, Issue 1 (4-2012)
Abstract
Background and Aims: Since impression materials usually contact with saliva, blood, and oral soft tissues, their microbial contamination are harmful in immunocompromised patients. The aim of the present study was to determine the bacterial and fungal contamination in common impression materials.
Materials and Methods: In current lab trial study, 5 different samples from each 4 impression materials were homogenized in 1 ml Tween 80 and then 100µl of each sample were cultured onto blood agar, EMB, or sabouraud dextrose agar. Bacterial and fungal cultures were incubated at 37º C and 30º C, respectively. The isolated bacterial and fungal colonies were enumerated and identified using specific diagnostic media and tests. Data were analyzed using Kruskal-Wallis test.
Results: Totally 75% of samples had one or several bacterial contaminations. Iranian alginate and Speedex (putty) were the most contaminated samples. On the other hand, Speedex (light body) and foreign alginate showed lower contamination. Species of Micrococcus, Staphylococcus, Bacilluses, Corynebacteria, gram negative Citrobacter, Actinomycetes and Neisseria were isolated from the analyzed impression materials. Aspergillus, Penicillium, Alternaria, Cladosporium and Sepdonium were the fungi isolated from impression materials. Statistical significant difference was shown between bacterial contamination of Iranian and foreign alginates (P=0.001). There was no statistical significant differences between the bacterial and fungal isolated colonies (CFU/gr) of 4 tested impression materials (P=0.21).
Conclusion: Several opportunistic bacteria and fungi were isolated from impression materials especially from Iranian alginate and Speedex putty which indicated their contamination.
Elham Zajkani, Habib Zeighami, Alireza Zaeefjou,
Volume 30, Issue 1 (6-2017)
Abstract
Background and Aims: Dental caries is an infectious disease transmitted by multiple factors in the mouth and one of the most common chronic diseases in the world that requires a lot of treatment expenses. The aim of this study was to evaluate the effect of fluoride 0.2% and Fuchs mouthwash (a combination of xylitol and fluoride 920 ppm) against two bacterial growths (Streptococcus mutans and Lactobacillus acidophilus).
Materials and Methods: In this in vitro study, first the well diffusion method and then MIC method (minimum inhibitory concentration) were used. Data were analyzed with Excell (2016).
Results: The results of the MIC method showed inhibitory effect of both mouthwashes in pure concentration (128 μg/ml). However, fluoride was effective in concentration higher than 32 μg/ml for Streptococcus mutans and higher than 2 μg/ml for lactobacillus acidophilus. Fuchs was effective for both bacteria at concentration higher than 64 μg/ml and in lower concentration it was ineffective. The results of the well diffusion test showed the inhibition of fluoride mouthwash in pure concentration on the Streptococcus mutans was (17 mm) and on the lactobacillus acidophilus 24 mm was obtained. In Fuchs mouthwash was zero and it represented effectiveness of fluoride on bacteria and ineffectiveness of Fuchs.
Conclusion: The fluoride mouthrinse in different concentrations, because of having a good inhibitory effect in both methods on Streptococcus mutans and Lactobacillus acidophilus was more effective compared with that of Fuchs mouthrinse.
Fatemeh Mokhtari , Kazem Koopaei, Jalil Modaresi, Hamid Reza Hemati, Hengameh Zandi,
Volume 30, Issue 3 (10-2017)
Abstract
Background and Aims: The purpose of this study was to evaluate the sealing ability of MTA and cold ceramic by using bacterial leakage method.
Materials and Methods: In this experimental study, fifty human single root extracted teeth were chosen. In group A, 20 teeth were filled with MTA and in group B, 20 teeth were filled with cold ceramic. Five teeth were used as a positive control (obturated using gutta-percha without sealer), and five teeth were used as negative control (obturated using gutta-percha with AH26 sealer and coated with two layers of nail varnish). A bacterial leakage model utilizing Enterococcus faecalis was used for evaluation of the sealing ability. The teeth were placed in test tubes, so that they formed two upper and lower compartments. The cultured bacteria in the upper chamber were in contact with the coronal area of the tooth. The root end was placed in the lower chamber containing sterile culture media. In this case, the filling of the root canal was only the communication path between the upper and lower chambers. In this method, the presence of turbidity in the lower chamber indicated that bacteria had penetrated through barrier and reached the medium. The leakage was measured. The acquired data was analyzed using Chi-square test.
Results: In group A (MTA), 7 samples and in group B (Cold ceramic), 4 samples should the leakage. In regarding the leakage, there was no statistically significant difference between MTA and cold ceramic. (P=0.288)
Conclusion: The results showed that the sealing ability of MTA and cold ceramic was similar as root filling materials.
Fatemeh Hemmati, Mansour Bayat, Kumarss Amini,
Volume 34, Issue 0 (5-2021)
Abstract
Background and Aims: Due to the increasing problems and side effects of the use of chemical antibacterial agents as well as antibiotic resistance, this study aimed to evaluate the effects of aloe vera gel on biofilm gene expression of sulfate-reducing bacteria (SRB) isolated from patients with periodontal infection by Real time-PCR method.
Materials and Methods: For this study, 100 individuals including 50 patients and 50 healthy individuals were recruited and examined by a periodontist. After identifying sulfate-reducing bacteria by biochemical tests and specific media, the effect of aloe vera extract on them was investigated and the expression of BFR gene against housekeeping gene (16srDNA) was determined by Real time- PCR test via T-test analysis method.
Results: The data showed that 12 strains of sulfate-reducing bacteria were isolated from the samples, 5 of which had BFR gene and their gene expression was significantly reduced by aloe vera gel (P<0.05). |
Conclusion: The data of this study in proving the anti-biofilm and antibacterial effects of aloe vera extract showed that the expression of the target gene is reduced. It seems that this substance can be used as an alternative to oral hygiene chemicals.
Background and Aims: Due to the increasing problems and side effects of the use of chemical antibacterial agents as well as antibiotic resistance, this study aimed to evaluate the effects of aloe vera gel on biofilm gene expression of sulfate-reducing bacteria (SRB) isolated from patients with periodontal infection by Real time-PCR method.
Materials and Methods: For this study, 100 individuals including 50 patients and 50 healthy individuals were recruited and examined by a periodontist. After identifying sulfate-reducing bacteria by biochemical tests and specific media, the effect of aloe vera extract on them was investigated and the expression of BFR gene against housekeeping gene (16srDNA) was determined by Real time- PCR test via T-test analysis method.
Results: The data showed that 12 strains of sulfate-reducing bacteria were isolated from the samples, 5 of which had BFR gene and their gene expression was significantly reduced by aloe vera gel (P<0.05). |
Conclusion: The data of this study in proving the anti-biofilm and antibacterial effects of aloe vera extract showed that the expression of the target gene is reduced. It seems that this substance can be used as an alternative to oral hygiene chemicals.
Dr Gelareh Eblaghian, Dr Alireza Reyhani Mohamadi, Miss Maryam Kalantari Nezhad,
Volume 34, Issue 0 (5-2021)
Abstract
Background and Aims: Nowadays, the best choice for replacing missing teeth are dental implants, however, failure is not unexpected. One of the factors that plays an important role in the implant failure is bacterial microleakage which could cause biological complication. The aim of this study was to compare the bacterial microleakage between the two types of implants.
Materials and Methods: In the present interventional study, SPI and Dentis implants were placed bilaterally in the premolar-molar area of the patients' mandible. One day and 14 days after the delivery of the crown, by removing the crown and removing the abutment, sampling was performed using a sterile paper cone from four areas. One day after sample culturing, the number of colonies was counted. All data were entered into SPSS 23 and were analyzed using independent samples t-test and paired t-test with a significance level of 0.05. |
Results: The amount of bacteria in
implant sulcus was significantly different between the two types of implants (P=0.003). After 14 days, the amount of bacteria in SPI implant sulcus significantly decreased more than Dentis implant sulcus (P=0.001). After 14 days, the amount of bacteria also decreased in all other areas which there were no significant difference between the two types of implants (P>0.05).
Mohammad Fazeli, Masomeh Ahmadi, Parisa Asadollahi, Hossein Seyedkhani, Elahe Karimi, Liela Ghitani, Nahid Mahdian, Dr Hossein Kazemian,
Volume 36, Issue 0 (5-2023)
Abstract
| Background and Aims: Root canal treatment failures are often attributed to incomplete removal of bacteria, particularly Enterococcus faecalis. While, chlorhexidine and sodium hypochlorite serve as conventional treatments. herbal medicine has been today considered as an alternative to synthetic medicine due to its safety. Therefore, the aim of the present study was to compare the antibactrial effect of Scrophularia Striata extract with chlorhexidine and sodium hypochlorite on Enterococcus Faecalis in the tooth root canal.
Materials and Methods: In this study, sixty extracted teeth were examined. Following the infection of dental canals with Enterococcus faecalis, materials were tested in 3 groups: 1) chlorhexidine 2% (18 teeth), 2) sodium hypochlorite 2.5% (18 teeth), and 3) Scrophularia striata (at the concentration obtained from MIC, 20%; 18 teeth). Additionally, the positive control and negative control were included (3 teeth in each group). Samples were then cultured on bile esculin agar. After 72 hours, black colonies were eaxamined. Chi-squared test was used to analyze the results.
Results: Enterococcus faecalis bacteria grew in 6, 8, and 17 out of the 18 teeth within the sodium hypochlorite, chlorhexidine, and Scrophularia striata extract groups, respectively. Consequently, the bactericidal effects for sodium hypochlorite, chlorhexidine, and Scrophularia striata extract were 66.6%, 55.5%, and 5.55%, respectively. |
Conclusion: The antibacterial effect of the Scrophularia striata extract was significantly lower than chlorhexidine and sodium hypochlorite on Enterococcus faecalis in dental canals viewed as a suitable replacement to the already in use synthetic therapeutic irrigants.
Neda Yousefi Nojookambari, Malihe Naderi, Razie Askari, Somayeh Talebi, Mana Mohammadhosseini, Sahar Shabani, Sajjad Yazdansetad,
Volume 37, Issue 0 (3-2024)
Abstract
Background and Aims: Oral bacteria play an important role in oral diseases, due to their high adaptability to different environmental areas of the mouth. In this article, an attempt was made to describe the molecular mechanisms involved in the physiological relationships of oral and dental environment bacteria and their pathogenic significance with molecular approaches.
Materials and Methods: The present systematic review was written based on the advanced and standard search of keywords including Oral bacteria, Biofilm, and Dental diseases in PubMed, Springer, Scopus, Medline, Google Scholar, Science Direct, and Web of Science databases. For this purpose, an advanced and systematic search of articles published from 1993 to 2023 was conducted to compile the present article.
Results: Bacteria in the oral cavity have nutritional adaptations that are important for living in pathogen-host relationships, including adapting to proteolytic living conditions, using the host's glycome as a nutritional interface. This includes the use of host-derived sialic acid and other glycosidases in oral bacteria. Some of these bacteria adhere to surfaces such as salivary, epithelial proteins, and glycans, which ultimately lead to biofilm formation. Bacteria living in the oral environment are constantly exposed to a wide range of stress-causing factors and oxidative stress in the biofilm.
Conclusion: Dental caries, pulp, periapical, and periodontitis diseases (including gingivitis) are among the most common bacterial diseases. Among them, tooth decay caused by the presence of Streptococcus mutans is the most common dental disease due to the production of acids from carbohydrate fermentation which is characterized by the demineralization of tooth structure.
