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Viability changes: microbiological analysis of dental casts.

Žilinskas J, Junevičius J, Ramonaitė A, Pavilonis A, Gleiznys A, Sakalauskienė J - Med. Sci. Monit. (2014)

Bottom Line: Klebsiella pneumoniae survived in plaster for up to 4 days, and the reduction in the number of these bacteria became statistically significant after 1 day (p<0.05).Escherichia coli disappeared after 2 days, and a reduction was already observed after 2 hours (p<0.05).Candida albicans in plaster models died within 2 days, and a reduction in their number was observed after 1 day (p<0.05).

View Article: PubMed Central - PubMed

Affiliation: Faculty of Odontology, Clinic of Dental and Maxillary Orthopedics, Lithuanian University of Health Sciences, Medical Academy, Kaunas, Lithuania.

ABSTRACT

Background: This study evaluated the survival of the most prevalent oral bacteria and fungi (Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, and Candida albicans) in dental casts, and compared changes in the amounts of these microorganisms at different time intervals to determine how long dental casts may pose threat to the health of dental personnel and patients.

Material and methods: When manufacturing the casts, regular water was replaced with sterile distilled water, where suspensions of the studied bacteria or the fungus at certain concentrations were prepared. When the dental casts were fully set (solidified), plaster shavings were examined immediately after the contact of the studied microorganism with the plaster, as well as after 1, 2, 24, 48, 72, 96, and 120 hours. Following that, we measured how the amount of the studied bacteria and fungi in 1 gram of the plaster changed within the studied period of time.

Results: Klebsiella pneumoniae survived in plaster for up to 4 days, and the reduction in the number of these bacteria became statistically significant after 1 day (p<0.05). Staphylococcus aureus remained viable in plaster for up to 4 days, and the number of these bacteria dropped after 1 day (p<0.05). Escherichia coli disappeared after 2 days, and a reduction was already observed after 2 hours (p<0.05). Candida albicans in plaster models died within 2 days, and a reduction in their number was observed after 1 day (p<0.05).

Conclusions: The microorganisms did not multiply in the gypsum casts and their number significantly dropped instead of increasing.

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Related in: MedlinePlus

Changes in the number of Staphylococcus aureus ATCC 25928 in 1g of the gypsum cast.
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f2-medscimonit-20-932: Changes in the number of Staphylococcus aureus ATCC 25928 in 1g of the gypsum cast.

Mentions: S. aureus survived in gypsum casts for up to 3 days. After the first and the second hour in the gypsum cast, the number of bacteria remained nearly unchanged. It was only after 2 days that a statistically significant difference was detected (a reduction from 59154±676 to 9285±102, p<0.05). Gram-positive bacteria (staphylococci) remained viable for up to 3 days in the gypsum casts, presumably due to their cell membrane composed of a thick peptidoglycan layer, a microcapsule (a thin layer of mucus over the cell membrane), and high resistance to environmental factors (Figure 2).


Viability changes: microbiological analysis of dental casts.

Žilinskas J, Junevičius J, Ramonaitė A, Pavilonis A, Gleiznys A, Sakalauskienė J - Med. Sci. Monit. (2014)

Changes in the number of Staphylococcus aureus ATCC 25928 in 1g of the gypsum cast.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4061146&req=5

f2-medscimonit-20-932: Changes in the number of Staphylococcus aureus ATCC 25928 in 1g of the gypsum cast.
Mentions: S. aureus survived in gypsum casts for up to 3 days. After the first and the second hour in the gypsum cast, the number of bacteria remained nearly unchanged. It was only after 2 days that a statistically significant difference was detected (a reduction from 59154±676 to 9285±102, p<0.05). Gram-positive bacteria (staphylococci) remained viable for up to 3 days in the gypsum casts, presumably due to their cell membrane composed of a thick peptidoglycan layer, a microcapsule (a thin layer of mucus over the cell membrane), and high resistance to environmental factors (Figure 2).

Bottom Line: Klebsiella pneumoniae survived in plaster for up to 4 days, and the reduction in the number of these bacteria became statistically significant after 1 day (p<0.05).Escherichia coli disappeared after 2 days, and a reduction was already observed after 2 hours (p<0.05).Candida albicans in plaster models died within 2 days, and a reduction in their number was observed after 1 day (p<0.05).

View Article: PubMed Central - PubMed

Affiliation: Faculty of Odontology, Clinic of Dental and Maxillary Orthopedics, Lithuanian University of Health Sciences, Medical Academy, Kaunas, Lithuania.

ABSTRACT

Background: This study evaluated the survival of the most prevalent oral bacteria and fungi (Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, and Candida albicans) in dental casts, and compared changes in the amounts of these microorganisms at different time intervals to determine how long dental casts may pose threat to the health of dental personnel and patients.

Material and methods: When manufacturing the casts, regular water was replaced with sterile distilled water, where suspensions of the studied bacteria or the fungus at certain concentrations were prepared. When the dental casts were fully set (solidified), plaster shavings were examined immediately after the contact of the studied microorganism with the plaster, as well as after 1, 2, 24, 48, 72, 96, and 120 hours. Following that, we measured how the amount of the studied bacteria and fungi in 1 gram of the plaster changed within the studied period of time.

Results: Klebsiella pneumoniae survived in plaster for up to 4 days, and the reduction in the number of these bacteria became statistically significant after 1 day (p<0.05). Staphylococcus aureus remained viable in plaster for up to 4 days, and the number of these bacteria dropped after 1 day (p<0.05). Escherichia coli disappeared after 2 days, and a reduction was already observed after 2 hours (p<0.05). Candida albicans in plaster models died within 2 days, and a reduction in their number was observed after 1 day (p<0.05).

Conclusions: The microorganisms did not multiply in the gypsum casts and their number significantly dropped instead of increasing.

Show MeSH
Related in: MedlinePlus