<title>Novel CO2 laser system for hard tissue ablation</title>

Abstract

A line-tunable and variable pulselength CO<SUB>2</SUB> laser system for ablation of dental and bone tissues has been tested. To avoid the undesirable effects of plasma formation, acoustic shock waves and collateral thermal damage to the tissues, we have found an optimum laser pulselength in the 10 - 20 microseconds range. At a fluence of 30 J/cm<SUP>2</SUP> and laser wavelength of 10.6 micrometers the ablation depths in enamel (dentin) were 12(18) micrometers and no significant noise was observed. Without water cooling enamel showed no visible color change, while some minimal carbonization of dentin was present even at low pulse repetition frequencies.