Bacterial detachment from salivary conditioning films by dentifrice supernates.
This study compared the detachment by supernates of nine different dentifrices of four oral bacterial strains adhering to a salivary pellicle in a parallel plate flow chamber. Ultra-thin bovine enamel slabs were coated for 1.5 h with human whole saliva. Following buffer rinsing, a bacterial suspension of Streptococcus oralis, Streptococcus sanguis, Streptococcus mutans or Actinomyces naeslundii was perfused through the flow chamber at a shear rate of 30 s-1 for four hours, and the number of adhering bacteria n4h was enumerated by image analysis after buffer rinsing at the same shear rate. Then, a 25 wt%-dentifrice/water supernate was perfused through the flow chamber for four minutes, followed by eight minutes of buffer rinsing and another enumeration of the number of bacteria that had remained adhering nad. Finally, an air-bubble was passed through the flow chamber to mimic the occasionally high detachment forces occurring in the oral cavity, and the adhering bacteria nab were counted again. On average, S. sanguis was the easiest to detach (73% averaged over all dentifrice supernates), while A. naeslundii was the most difficult (22% on average). The combined detachment of bacteria by dentifrice supernates and air-bubble ranged from a low of 16% to a high of 80%. Dentifrices containing pyrophosphate and polymeric polyphosphate (hexametaphosphate) surface active ingredients appeared to produce the most consistent and strongest desorption effects on plaque bacteria. Factors apparently important to bacterial detachment from pellicle-covered tooth surfaces by dentifrice formulations include the nature of adhesion of bacterial strains and chemical composition of the dentifrice formulations, including pH, surfactant system and the effect of added ingredients (dispersants, metal ions, peroxides, baking soda).
van der Mei
Henny C
HC
Department of Biomedical Engineering, University of Groningen, Groningen, The Netherlands. H.C.van.der.Mei@med.rug.nl
White
Donald  J
D
Cox
Ed  R
E
Geertsema-Doornbusch
Gesinda  I
G
Busscher
Henk  J
H
D000190:Actinomyces / Q000187:drug effects; D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects*; D002417:Cattle; D045424:Complex Mixtures; D003741:Dental Deposits / Q000382:microbiology*; D044622:Dental Pellicle; D003802:Dentifrices / Q000494:pharmacology*; D003902:Detergents / Q000494:pharmacology; D011756:Diphosphates / Q000494:pharmacology; D004338:Drug Combinations; D004563:Electrochemistry; D005459:Fluorides; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D010710:Phosphates / Q000494:pharmacology; D012463:Saliva / Q000382:microbiology*; D012824:Silicic Acid; D017693:Sodium Bicarbonate / Q000494:pharmacology; D012969:Sodium Fluoride / Q000494:pharmacology; D013295:Streptococcus mutans / Q000187:drug effects; D019533:Streptococcus oralis / Q000187:drug effects; D013499:Surface Properties / Q000187:drug effects; D014002:Tin Fluorides / Q000494:pharmacology; D014100:Toothpastes; D014260:Triclosan; D014993:Xylitol / Q000494:pharmacology
D045424:Complex Mixtures; C438183:Crest Dual Action Whitening dentifrice; C098421:Crest Gum Care; C115762:Crest Multicare; C098422:Crest Tartar Control; D003802:Dentifrices; D003902:Detergents; D011756:Diphosphates; D004338:Drug Combinations; C098761:Mentadent Dentifrice; D010710:Phosphates; D014002:Tin Fluorides; D014100:Toothpastes; C546060:hydrated silica gel-based toothpaste; D012824:Silicic Acid; D014260:Triclosan; D017693:Sodium Bicarbonate; D012969:Sodium Fluoride; D006861:Hydrogen Peroxide; C009285:sodium polymetaphosphate; D005459:Fluorides; D014993:Xylitol