bovine serum albumin, inactivation, mineral trioxide aggregate
Z Mohammadi. The Effect of Bovine Serum Albumin on the Antifungal Activity of Mineral Trioxide Aggregate Cements. The Internet Journal of Dental Science. 2007 Volume 6 Number 1.
The aim of this study was to evaluate the effect of bovine serum albumin (BSA) on the antifungal effect of gray-colored MTA (GMTA) and white-colored MTA (WMTA) using a tube-dilution test. MTA preparations were tested freshly mixed and after 24 h on Candida albicans. The experiment was performed in 24-well culture plates. Fifty wells were used and divided into two experimental groups (freshly-mixed WMTA, freshly-mixed WMTA plus BSA, freshly-mixed GMTA, and freshly-mixed GMTA plus BSA) 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 positive control group. All plates were incubated at 37°C for1h, 24 h, and 72 h. Growth of fungi was monitored daily by the presence of turbidity. Results showed the inhibitory effect of BSA on the antifungal effect of MTA cements during 24-h and 72-h incubation, whereas, there was no significant difference between 1-h incubation groups. It was concluded that the antifungal effect of freshly mixed MTA cements was decreased in the presence of BSA.
Microorganisms play an essential role in pulpal and periapical disease (1,2,3). Throughout the past decades, it has been well known that yeasts can be isolated from infected root canals. The occurrence of yeasts reported in infected root canals varies between 1% and 17 %( 4).
It has been shown that fungi colonization resulting in radicular pathosis can be associated with failing root canal treatments (5,6,7,8,9). The most commonly recovered fungi were
Factors affecting the colonization of the root canal by fungi are not fully understood. However, it seems that among the predisposing factors of this process are certain intracanal medicaments, local and systemic antibiotics, and previous unsuccessful endodontic treatment. It has been hypothesized that the reduction of specific bacteria in the root canal during endodontic treatment may allow fungi overgrowth in the low nutrition environment. Further, fungi, such as
Failures of initial endodontic treatment can often be successfully treated by orthograde retreatment or endodontic surgery. Elimination of the microbial flora and infected tissue as well as complete seal of the root canal system, to prevent future recontamination, will enhance treatment success (11). Mineral trioxide aggregate (MTA) has become a popular material to seal off communications between the root canal system and external surface of the root. It has been mostly used as a retrograde filling material and as a sealant of root perforations (12).
MTA (Pro Root MTA, Dentsply/Tulsa Dental, Tulsa, OK) is marketed in gray – coloured and white – coloured preparations; both are 75% Portland cement, 20% bismuth oxide, and 5% gypsum by weight (11). In recent years, the use of the white – coloured preparation became more popular. MTA is a powder that consists of fine hydrophilic particles that in the presence of water or moisture forms a colloidal gel that solidifies to form hard cement within approximately 3h (12). The main components of the gray – coloured formula are tricalcium oxide, tricalcium silicate, bismuth oxide, dicalcium, silicate, tricalcium aluminate, tetracalcium aluminoferrite, and calcium sulfate dihydrate. The white-colored preparation, however, lacks tetracalcium aluminoferrite (11). A number of studies have revealed the inhibitory effect dentin, dentin matrix, bovine serum albumin (BSA), and hydroxyapatite on the antimicrobial activity of several intracanal medicaments (i.e. calcium hydroxide). Considering the fact that calcium hydroxide is the main chemical compound produced by MTA cements in aqueous environments, evaluation of inhibitory effect of bovine serum albumin (BSA) on the antimicrobial effects of these cements seems to be interesting. The purpose of this study was to assess the inhibitory effect of BSA on the antifungal effects of MTA cements against
Materials and Methods
The antifungal activity of white – coloured MTA (Pro Root MTA, Dentsply/Tulsa Dental, Tulsa, OK) as well as gray – coloured MTA (Pro Root MTA, Dentsply/Tulsa Dental, Tulsa, OK) was evaluated against
The negative control showed no fungal growth in all experimental periods, whereas the positive control demonstrated entirely fungal growth, which confirms the method.
Evaluation of the freshly mixed MTA groups without BSA demonstrated fungal growth during the 1-h incubation of
The method used in the present study is the dilution – tube – susceptibility test, which is an effective method to evaluate the antifungal and antibacterial properties of any filling material or solution (13). This method allows direct contact between fungal cells and the MTA material. Sabouraud agar is a commonly used medium for the isolation of oral yeasts. The pH of the medium is quite acidic (usually 5.6) allowing the growth of yeasts and aciduric organisms, whereas most bacteria are inhibited (4).
It is generally known that organic material can inactivate or weaken the effect of calcium hydroxide. Portenier
The results of the present study showed that freshly mixed and 24 –h set MTA cements without BSA were effective against
In another in vitro study, Sipert
Extrapolation of the results of this in vitro study to clinical situations must be done with caution. Sealing ability and biocompatibility of MTA are more important from the clinical point of view. Further, the 72 h evaluation of the MTA cements is not sufficient for any conclusions to be drawn about their antifungal effects. Therefore, it is suggested that the antifungal activity of MTA cements be investigated for longer periods of time.
In conclusion, within the limits of the present study, antifungal activity of white – colored as well as gray – colored MTA was completely inhibited in the presence of BSA.