Aluminum oxide air abrasion particles: a bacteriologic and SEM study.
OBJECTIVE
The objective is to determine if aerobic and anaerobic sampling yields viable biologic contaminants in the aluminum oxide air abrasion powder as delivered by the manufacturer and to determine mean particle size for comparison with the published size from manufacturers and the range of sizes in the powders.


METHODS
Samples from 15 unopened aluminum oxide powder containers from 9 different manufacturers were plated on aerobic and anaerobic culture media. The cultures were incubated at 35 degrees C and observed at 24-hour intervals. Samples of each of the 15 groups were subjected to scanning electron microscope (SEM) examination. Photomicrographs were obtained and a range and mean particle size determined.


RESULTS
Aerobic and anaerobic cultures demonstrated no growth in any of the samples. Mean particle size determined by SEM for 25- to 27.5-micron particles ranged from 27.3 microns to 32.0 microns with standard deviations from 1.06 microns to 7.70 microns. Mean particle size for 50 microns particles ranged from 51.6 microns to 59.7 microns with standard deviations of 5.48 microns to 14.80 microns.


CONCLUSIONS
Aluminum oxide powders as delivered by manufacturers appeared to be free from viable microorganisms. The powder mean particle sizes approximate the labeled sizes closely enough such that they should perform properly in air abrasion tooth preparation.
Kofford
K R
KR
Advanced Education in General Dentistry Program, Texas A&M University Health Science Center, Baylor College of Dentistry, Dallas, Texas 75246, USA.
Wakefield
C W
CW
Murchison
D F
DF
D000537:Aluminum Oxide / Q000737:chemistry / Q000592:standards; D001420:Bacteria, Aerobic / Q000254:growth & development*; D001421:Bacteria, Anaerobic / Q000254:growth & development*; D003470:Culture Media; D004340:Drug Contamination; D019243:Enamel Microabrasion; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010316:Particle Size
D003470:Culture Media; D000537:Aluminum Oxide