Removal of bacterial endotoxin from root surface with Er:YAG laser.
OBJECTIVE
To determine the potential of 2.94 microm Er:YAG laser radiation to remove bacterial endotoxin from root surfaces.


METHODS
40 extracted teeth were divided into four groups of 10 samples each. A 16 mm2 area of the root surface on each sample was inoculated with an aliquot of 7 microl of a lipopolysaccharide suspension at a concentration of 50 IU/ml. LPS was derived from a non-oral Escherichia coli strain (E. coli 055:B5). Source of laser radiation was an Er:YAG laser emitting pulsed infrared radiation at a wavelength of 2.94 microm, with a pulse duration of 250 micros, and a pulse repetition rate of 15 pps. Three specimen groups were irradiated with 105 laser pulses at a radiation energy of 60 mJ, 100 mJ and 140 mJ. One specimen group was untreated (control). The LPS concentration with each sample was determined using a chromogenic, quantitative Limulus-amoebocyte-lysate assay. Statistical analysis was ANOVA and Scheffé-test.


RESULTS
Mean LPS yield from the untreated control samples was 50.1 (+/- 35.9) IU/ml. Following laser irradiation the average LPS on the root surfaces was 19.86 (+/- 14.4) IU/ml at 60 mJ, 12.86 (+/- 8.1) IU/ml at 100 mJ and 8.58 (+/- 4.9) IU/ml at 140 mJ.
Folwaczny
Matthias
M
Department of Operative Dentistry and Periodontology, Ludwig-Maximilians University, Goethestr. 70, 80336 Munich, Germany. mfolwa@dent.med.uni-muenchen.de
Aggstaller
Hans
H
Mehl
Albert
A
Hickel
Reinhard
R
D003666:Decontamination / Q000379:methods; D012534:Dental Scaling / Q000295:instrumentation / Q000379:methods*; D004731:Endotoxins / Q000528:radiation effects*; D004871:Erbium; D004926:Escherichia coli; D006801:Humans; D066298:In Vitro Techniques; D053685:Laser Therapy; D014092:Tooth Root / Q000382:microbiology / Q000528:radiation effects / Q000601:surgery*; D015018:Ytterbium
D004731:Endotoxins; D004871:Erbium; D015018:Ytterbium