Subgingival microbiologic effects of one-time irradiation by CO2 laser: a pilot study.
BACKGROUND
Third-generation carbon dioxide (3-CO(2)) lasers have handpieces that accommodate a periodontal insert that permits irradiation directly into the periodontal pocket/sulcus. The purpose of this pilot study was to evaluate, by scanning electron microscopy (SEM), the surface effects of 3-CO(2) laser treatment on the root surfaces and soft tissues and to investigate the effects of 3-CO(2) laser on periodontal pathogenic bacteria compared to negative controls.


METHODS
Five patients with chronic periodontitis and treatment planned for a maxillary immediate denture were included in the study. Periodontal pockets with a mean probing depth of 5.5 +/- 0.8 mm were irradiated one time by CO(2) laser (wavelength of 10,600 nm) at a power of 2.2 W, 50 Hz, an 80-millisecond pulse length, and an exposure rate of 1 mm per 5 seconds. DNA analysis of eight periodontal bacteria was performed on samples collected from laser-treated and control sites prior to and immediately following treatment and was compared between groups. In addition, block biopsies, including soft tissue, were harvested for SEM examination.


RESULTS
SEM examination of test group specimens showed heat damage on the soft tissues in three of 17 specimens (17.6%). In addition, 11.7% (two of 17) of the 3-CO(2)-treated teeth exhibited localized slight damage to root surfaces. Microbiologic results of the control sites indicated that 90.6% of the bacterial counts remained the same, 6% increased, and 3% decreased. In the test group, 71.25% of the bacterial count analyses for the eight different periodontal microbes remained the same, 12.50% increased, and 16.25% decreased.


CONCLUSIONS
A one-time use of the 3-CO(2) laser in periodontal pockets did not sterilize or substantially reduce subgingival bacterial populations compared to negative controls.
Department of Periodontics, School of Dentistry, University of Missouri-Kansas City, Kansas City, MO 64108, USA. mullinss@umkc.edu
Stephanie L
SL
Mullins
Simon R
SR
MacNeill
John W
JW
Rapley
Karen B
KB
Williams
J David
JD
Eick
Charles M
CM
Cobb
D000368:Aged; D002056:Burns / Q000209:etiology; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D005881:Gingiva / Q000293:injuries; D006801:Humans; D053685:Laser Therapy / Q000009:adverse effects*; D054020:Lasers, Gas; D008297:Male; D050296:Microbial Viability; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D010514:Periodontal Pocket / Q000382:microbiology* / Q000601:surgery*; D010865:Pilot Projects; D014092:Tooth Root / Q000293:injuries
D004269:DNA, Bacterial