Biomedical subjects

Zahed Mohammadi

Publications and source records attributed to Zahed Mohammadi.

5 recordsLinked to original sources

PubMed2006

Evaluation of the antifungal effects of mineral trioxide aggregate materials.

The aim of this study was to evaluate and compare the antifungal effect of white-coloured mineral trioxide aggregate (WMTA) and grey mineral trioxide aggregate (GMTA) using a tube-dilution test. MTA preparations were freshly mixed and tested after 24 h on Candida albicans. The experiment was carried out in 24-well culture plates. Fifty wells were used and divided into four experimental groups (freshly mixed WMTA, freshly mixed GMTA, 24 h-set WMTA and 24 h-set GMTA) of 10 wells each and control groups of five wells each. Plates of Sabouraud dextrose agar mixed with C. albicans served as positive control, and Sabouraud dextrose agar without C. albicans served as negative control. Fresh inoculate of C. albicans was prepared by growing an overnight culture from a stock culture. Aliquots of C. albicans were then taken from the stock culture and plated on the agar compound of the experimental and control groups. All plates were incubated at 37 degrees C for 1, 24 and 72 h. Growth of fungi was monitored daily by the presence of turbidity. Results showed that in the freshly mixed as well as 24 h-set MTA cements fungal growth was observed during 1-h incubation, whereas by increasing the incubation time, no fungal growth was observed in 24 and 72 h. It was concluded that MTA cements (freshly mixed and 24-h set) were effective against C. albicans.

Aluminum Compounds↗

PubMed2006

Evaluation of the antibacterial substantivity of several intra-canal agents.

The aim of this in vitro study was to compare the antimicrobial substantivity of 2% chlorhexidine gluconate (CHX), 100 mg ml(-1) doxycycline and 2.6% sodium hypochlorite (NaOCl) in bovine root dentine. Eighty dentine tubes prepared from bovine incisors were infected in vitro for 14 days with Enterococcus faecalis. The specimens were divided into five groups as follows: doxycycline HCl; CHX; NaOCl; infected dentine tubes (positive control); and sterile dentine tubes (negative control). Dentine chips were collected with round burs into tryptic soy broth. After culturing, the number of colony-forming units (CFU) was counted. In all experimental groups, the number of CFU was minimum in the first cultures, and the results obtained were significantly different from each other at any time period (P < 0.05). In the first culture, the NaOCl group and doxycycline HCl group showed the lowest and highest number of CFU, respectively. In each group, the number of CFU increased significantly by time-lapse (P < 0.05). In conclusion, the substantivity of CHX was significantly greater than NaOCl and doxycycline.

Analysis of Variance↗

PubMed2006

One-visit versus multiple-visit endodontic therapy--a review.

A growing perception in endodontic circles is that root canal therapy requires one treatment visit only. One-visit endodontics offers many potential advantages. It is less time-consuming, resulting in less cost for the patient, potentially more profit for the dentist, less painful and less traumatic than multi-visit treatment. Conversely, if the pulp is necrotic and/or associated with periradicular disease, the root canal system is infected. In these cases, the root canal system should ideally be cleaned, an intracanal medication placed, and the canal filled at a second visit. In this paper we aim to review several aspects of one-visit versus multi-visit endodontic treatment and future perspectives in this field.

Bacterial Infections↗

PubMed2005

Calcium hydroxide: a review.

Calcium hydroxide is a multipurpose agent, and there have been an increasing number of indications for its use. Some of its indications include direct and indirect pulp capping, apexogenesis, apexification, treatment of; root resorption, iatrogenic root perforations, root fractures, replanted teeth and interappointment intracanal dressing. The purpose of this paper is to review the properties and various indications for the use of calcium hydroxide.

Anti-Bacterial Agents↗

PubMed2005

In vitro evaluation of antibacterial activities of root canal sealers.

OBJECTIVE: The purpose of this study was to compare the antimicrobial effect of AH-26 (a resin-based sealer), Dorifill (a ZOE-based sealer), and pure ZOE after 24 hours and after one week. METHODOLOGY: All sealers were prepared according to the manufacturers' directions immediately before testing. The micro-organisms used in this assay included Staphylococcus aureous and Streptococcus mutans, which were prepared from isolated species in the microbiology laboratory. The antimicrobial effects of each sealer were determined by measuring the diameter of the zone of inhibition in millimeters after incubation at 37 degrees C for 24 hours and seven days in a humid atmosphere. Each test was repeated three times. RESULTS: In the 24-hour samples, the antibacterial activity of AH-26 was significantly greater than two other materials tested on both bacteria (p < 0.05). The antibacterial activity of Dorifill and ZOE on S. aureous was not significantly different from each other (p > 0.05), but Dorifill had a significantly greater effect on S. mutans than ZOE (p < 0.05). In the seven-day samples, statistically significant zones of bacterial growth inhibition for both bacterial species tested were observed in descending order of antibacterial activity as ZOE > AH-26 > Dorifill (p < 0.05). CONCLUSION: The products studied exhibited some variable antibacterial properties. In 24 hours, the AH-26 exerted the greatest activity against both organisms tested. By seven days, the ZOE-based sealer-Dorifill-showed lower antibacterial activity than AH-26 and pure ZOE.

Anti-Bacterial Agents↗