Change in temperature of subjacent bone during soft tissue laser ablation

Citation
P. Spencer et al., Change in temperature of subjacent bone during soft tissue laser ablation, J PERIODONT, 69(11), 1998, pp. 1278-1282
Citations number
17
Categorie Soggetti
Dentistry/Oral Surgery & Medicine","da verificare
Journal title
JOURNAL OF PERIODONTOLOGY
ISSN journal
00223492 → ACNP
Volume
69
Issue
11
Year of publication
1998
Pages
1278 - 1282
Database
ISI
SICI code
0022-3492(199811)69:11<1278:CITOSB>2.0.ZU;2-P
Abstract
IN TISSUES THAT CLOSELY APPROXIMATE bone, sufficient heat may be transferre d to the bone during laser surgery to cause damage and/or necrosis. To date , there have been few studies examining the temperatures elicited at the bo ne surface as a result of laser application to the overlying soft tissues. The purpose of this investigation was to determine, under in vitro conditio ns, temperature changes at the bone/soft tissue interface during laser abla tion with CO2 and Nd:YAG lasers used with and without (w/wo) air/water cool ant. Experimental specimens consisted of 5 mandibles from freshly sacrifice d hogs; laser treatment sites were the buccal and lingual attached gingiva of the molars and the lingual keratinized mucosa of the incisor region. CO2 and Nd:YAG lasers were used w/wo coolant at power settings of 4 to 8 W and 5 to 9 W, respectively. Temperature changes were measured with a copper co nstant thermocouple contained within a 21 gauge hypodermic needle. In compa ring the lasers at comparable energy densities w/wo coolant, temperature in creases at the bone/soft tissue interface ranged from 8.0 to 11.1 degrees C with the Nd:YAG and 1.4 to 2.1 degrees C with the CO2. Similarly, in compa ring the times required for the interface to return to baseline temperature following removal of the laser, values ranged from similar to 143 to 205 a nd similar to 119 to 139 seconds for the Nd:YAG and CO2, respectively. Resu lts from this study suggest that, at energy densities equal or above those reported here, the increase in temperature at the bone surface as a result of periodontal soft tissue surgery with the Nd:YAG laser could be damaging, especially if the exposure is prolonged.