Does mechanical pressure force bacteria into the dentinal tubules of carious and non-carious teeth--an exploratory study.
BACKGROUND
Although many researchers have confirmed bacterial migration within dentine, no evidence was found to show whether bacteria can be easily forced into dentine during caries treatment.


OBJECTIVE
This exploratory study was to see if bacteria could be easily forced into dentinal tubules of carious and non-carious teeth using hand excavation and air pressure.


METHODS
Two (2) carious and ten (10) non-carious teeth were used. Class I (Black's Classification) cavities were created using rotary instruments in the non-carious teeth, while the carious teeth were excavated using hand instruments to remove the caries. The cavity of one carious tooth was etched and in the other tooth was not. Five (5) of the non-carious tooth cavities were etched, of which, one tooth was also disinfected. The remaining five non-carious teeth were not etched and included one tooth that was disinfected. Bacterial cultures of S. mutans, E. coli and Veilonella were placed in the prepared cavities and hand excavators and air pressure were used in an attempt to force bacteria down into the dentinal tubules. Thereafter, the teeth were fixed, decalcified and prepared for electron or light microscopy.


RESULTS
One etched, and one etched and disinfected non-carious tooth showed bacteria in the dentinal tubules. One carious tooth (etched) showed bacterial presence in the dentinal tubules.


CONCLUSIONS
This study shows that it is difficult to force bacteria into dentinal tubules using hand excavation (as in the Atraumatic Restorative Treatment technique) so a definitive study is not indicated.
Harkison
B N
BN
Dental Research Institute, University of Witwatersrand, Johannesburg, South Africa.
Toi
C
C
Grossman
E S
ES
Cleaton-Jones
P E
PE
Parak
R
R
D000134:Acid Etching, Dental; D000399:Air Pressure; D018407:Bacterial Physiological Phenomena; D003731:Dental Caries / Q000382:microbiology* / Q000628:therapy; D003737:Dental Cavity Preparation / Q000295:instrumentation / Q000379:methods; D003793:Dental Restoration, Permanent / Q000295:instrumentation / Q000379:methods*; D003804:Dentin / Q000382:microbiology* / Q000648:ultrastructure; D004202:Disinfectants / Q000627:therapeutic use; D004926:Escherichia coli / Q000302:isolation & purification / Q000502:physiology; D006801:Humans; D008855:Microscopy, Electron, Scanning; D013295:Streptococcus mutans / Q000302:isolation & purification / Q000502:physiology; D014678:Veillonella / Q000302:isolation & purification / Q000502:physiology
D004202:Disinfectants