Components of variability that are related to estimating viable tooth surface streptococci were evaluated to assess the effect of real factors and to reduce residual error. Methods of dispersion (mechanical mixing vs ultrasonic agitation), plate count replication, sample site, weighing technic, balance error, and total experimental variability were considered.
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References
1.
Kraus, F.W., and Gaston, C.: Individual Constancy of Numbers Among the Oral Flora, J Bact71:703-707, 1956.
2.
Snedecor, G.W.: Statistical Methods, 5th ed, Iowa City: Iowa State University Press, 1956, p 44.
3.
Snyder,Thomas L.: The Relative Errors of Bacteriological Plate Counting Methods, J Bact54:641-654, 1947.
4.
Stralfors, A.: Investigations into the Bacterial Chemistry of Dental Plaques, AB, Thule, Stockholm, 1950.
5.
Green, G.E.; Dodd, M.C.; and Inverso, H.S.: Comparative Microflora of Developing Dental Plaques in Caries Immune and Susceptible Individuals, J Dent Res, 36 :331-337, 1957.
6.
Socransky, S.S. ; Gibbons, R.J.; Dale , A.C.; Bortnick, L.; Rosenthal, E.; and Macdonald, J.B.: The Microbiota of the Gingival Crevice Area of ManI. Arch Oral Biol86:275-280, 1963.