Pulpal and periodontal temperature rise during KTP laser use as a root planing complement in vitro.
OBJECTIVE
The purpose of this study was to define the optimal irradiation conditions of a KTP laser during root planing treatment.


METHODS
The surfaces of 60 single-root human teeth were scaled with conventional instruments before lasing. The pulpal temperature increase was measured by means of one thermocouple placed in the pulp chamber and a second one placed on the root surface at 1 mm from the irradiation site. The influence of variables of coloration by Acid Red 52 (photosensitizer), scanning speed, dentin thickness, and probe position was analyzed for a constant exposure time of 15 sec and 500 mw (spot size diameter, 0.5 mm). The pulpal temperature was below 3 degrees C for the adjustments.


RESULTS
The irradiation on one point of root surface had the following results: The application of photosensitizer on the root surface before lasing produced a 50% higher temperature rise within the pulp than in the case without the application of the photosensitizer. The temperature rise in the pulp chamber was below 3 degrees C with the following settings of 500 mw: PW = 10 msec and PRR < 35; or PW= 20 msec and PRR < 20 Hz. On the other hand, for the same irradiation conditions, the temperature rise on the surface of the root was always below 7 degrees C. However, the temperature increase became higher than 7 degrees C (on the surface of the root) in the case of P > 500 mw, PW > 50 msec and PRR > 10 Hz of root surface or a scanning speed of irradiation of 1 mm/sec for a linear irradiation of 4 mm.


CONCLUSIONS
The KTP laser may be used safely without thermal damage to pulp and periodontal tissue with respect to the biologically acceptable previously described parameters.
Nammour
S
S
Department of Dental Sciences, Faculty of Medicine, University of Liege, Liege, Belgium. nammourdent@hotmail.com
Rocca
J-P
JP
Keiani
K
K
Balestra
C
C
Snoeck
T
T
Powell
L
L
Reck
J Van
JV
D001831:Body Temperature / Q000502:physiology*; D003782:Dental Pulp / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D007834:Lasers; D010710:Phosphates; D016745:Root Planing; D014025:Titanium
D010710:Phosphates; C064806:potassium titanylphosphate; D014025:Titanium