A study on the morphological changes of the rat mandibular bone with TEA CO2 laser

J Clin Laser Med Surg. 1999 Oct;17(5):211-5. doi: 10.1089/clm.1999.17.211.


Objective: The purpose of this study was to investigate the morphological changes of the bone structure induced by transversely excited, atmospheric TEA pressure CO2 laser irradiation. Moreover, the healing process at 3 weeks was also observed.

Summary background data: It has been demonstrated that dental hard tissue can be removed by a long pulse of TEA CO2 laser irradiation with minimal thermal damage. However, there are few studies on the morphological changes of the TEA CO2 laser on bone tissue.

Methods: The TEA CO2 laser was irradiated on the surface of the rat mandibular bone under the following irradiation conditions: wavelength, 10.6 microns; output, 95 mJ/pulse; pulse repetition rate, 1 Hz; irradiation time, 7.5 microseconds/shot; spot size, 0.8 x 1.5 mm; energy density, 7.9 J/cm2. Histological and scanning electron microscopic examinations were performed.

Results: In the stereoscopic examination, a defect with clean-cut margins was produced. In the light microscopic examination, a basophilic line at the bottom of the defect was noted. Examining the defect with SEM, a smear-like appearance and cone structures were found. In the histological examination, a healing process by formation of new bones at the junction site was recognized.

Conclusions: These findings suggest that it is possible to remove bone tissues by TEA CO2 laser irradiation. However, a particle-like structure associated with a basophilic line and melted surface indicated that some thermal damage was produced during the laser irradiation.

MeSH terms

  • Animals
  • Lasers*
  • Male
  • Mandible / anatomy & histology*
  • Mandible / radiation effects*
  • Mandible / ultrastructure
  • Rats
  • Rats, Wistar