Effect of an essential oil-containing dentifrice on dental plaque microbial composition.
OBJECTIVE
To determine the effect of 6 months use of an essential oil-containing (EO) antiplaque/antigingivitis fluoride dentifrice on the balance of the oral microbial flora and on the emergence of resistant microbial forms by analysis of dental plaque and saliva.


METHODS
The dentifrice essential oils consisted of a fixed combination of thymol, menthol, methyl salicylate, and eucalyptol. An identical fluoride-containing dentifrice without the essential oils served as the control. A subgroup of 66 subjects from a clinical trial population of 321 was randomly selected for characterization of their dental plaque microflora. Saliva was also cultured to monitor for the emergence of opportunistic pathogens. Supragingival plaque and saliva were harvested at baseline, after which subjects received a dental prophylaxis. Subjects were sampled again after 3 and 6 months of product use prior to clinical examination. Plaque was characterized for microbial content by phase contrast microscopy for recognizable cellular morphotypes and by cultivation on nonselective and selective culture media. Determination of the minimum inhibitory concentrations of the test agent against selected Actinomyces and Veillonella isolated bacterial species was conducted at all time points to monitor for the potential development of bacterial resistance.


RESULTS
There were no statistically significant differences between the microbial flora obtained from subjects using the essential oil-containing dentifrice and the vehicle control for all parameters and time periods except for the percentage of spirochetes at 6 months and for percentage of "other" microorganisms at 3 months. The EO group exhibited a lower adjusted mean for both parameters. Additionally, there was no evidence of the development of bacterial resistance to the antimicrobial activity of the essential oils or the emergence of opportunistic pathogens.
Charles
C H
CH
The Warner-Lambert Consumer Healthcare Division of the Warner-Lambert Consumer Group of Pfizer, Morris Plains, NJ 07950, USA. chris.charles@wl.com
Vincent
J W
JW
Borycheski
L
L
Amatnieks
Y
Y
Sarina
M
M
Qaqish
J
J
Proskin
H M
HM
D000190:Actinomyces / Q000187:drug effects / Q000254:growth & development; D000293:Adolescent; D000328:Adult; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D002327:Cariostatic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D015169:Colony Count, Microbial; D003470:Culture Media; D003511:Cyclohexanols / Q000008:administration & dosage / Q000627:therapeutic use; D003773:Dental Plaque / Q000382:microbiology* / Q000517:prevention & control; D003802:Dentifrices / Q000627:therapeutic use*; D004311:Double-Blind Method; D024881:Drug Resistance, Bacterial; D000077591:Eucalyptol; D005052:Eucalyptus; D005260:Female; D005459:Fluorides / Q000008:administration & dosage / Q000627:therapeutic use; D005500:Follow-Up Studies; D005891:Gingivitis / Q000517:prevention & control; D006801:Humans; D008297:Male; D008610:Menthol / Q000008:administration & dosage / Q000627:therapeutic use; D008858:Microscopy, Phase-Contrast; D008875:Middle Aged; D039821:Monoterpenes; D009822:Oils, Volatile / Q000008:administration & dosage / Q000627:therapeutic use*; D012459:Salicylates / Q000008:administration & dosage / Q000627:therapeutic use; D012463:Saliva / Q000382:microbiology; D013144:Spirochaetales / Q000187:drug effects / Q000254:growth & development; D013729:Terpenes / Q000008:administration & dosage / Q000627:therapeutic use; D013943:Thymol / Q000008:administration & dosage / Q000627:therapeutic use; D014678:Veillonella / Q000187:drug effects / Q000254:growth & development
D000891:Anti-Infective Agents, Local; D002327:Cariostatic Agents; D003470:Culture Media; D003511:Cyclohexanols; D003802:Dentifrices; D039821:Monoterpenes; D009822:Oils, Volatile; D012459:Salicylates; D013729:Terpenes; D008610:Menthol; D013943:Thymol; C033069:methyl salicylate; D005459:Fluorides; D000077591:Eucalyptol