Premium
The effects of C0 2 , Nd: YAG and Er: YAG lasers with and without surface coolant on tooth root surfaces
Author(s) -
Israel Michael,
Cobb Charles M.,
Rossmann Jeffrey A.,
Spencer Paulette
Publication year - 1997
Publication title -
journal of clinical periodontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.456
H-Index - 151
eISSN - 1600-051X
pISSN - 0303-6979
DOI - 10.1111/j.1600-051x.1997.tb00235.x
Subject(s) - laser , er:yag laser , materials science , irradiation , nd:yag laser , optics , nuclear physics , physics
The objective of this study was to compare and contrast the morphologic changes in tooth root surfaces treated in vitro by scaling and root planing followed by irradiation with the Er: YAG laser using air/water surface cooling and the C0 2 and Nd:YAG lasers, both with and without surface coolant. The experimental unit consisted of 42 freshly extracted teeth which were divided equally and randomly assigned to the following 7 treatment groups: untreated control, S/RP only. CO 2 laser with and without air/water surface cooling, Nd:YAG laser with and without/air water surface cooling, and Er:YAG laser with air/water surface coolant. Specimens treated with CO 2 laser irradiation were subjected to energy densities ranging from 100 to 400 J/cm 2 : those treated with the Nd:YAG from 286 to 1857 J/cm 2 : and the Er:YAG was used within a range of 20 to 120 J/cm 2 . The degree of morphologic change following CO 2 and Nd:YAG irradiation appeared directly related to energy density but unrelated to the use of surface coolant. Laser induced surface changes included cavitation, globules of melted and resolidified mineral, surface crazing, and production of a superficial char layer. In contrast, the Er:YAG laser produced root surface changes that might be expected from acid etching, i.e., removal of the smear layer and exposure of the collagen matrix. In addition, sharply denned microfractures of the mineralized structure were noted and unlike the CO 2 and Nd:YAG lasers, there was no evidence of melting or surface char. Given the parameters of this study, it appears that both the CO 2 and Nd:YAG lasers alter the root surface in an undesirable manner. The Er:YAG laser, however, when used at low energy densities shows sufficient potential for root surface modification to warrant further investigation.