Q-switched CTE:YAG (2.69 microns) laser ablation: basic investigations on soft (corneal) and hard (dental) tissues

Area of Science:

• Biomedical Engineering
• Laser Physics
• Surgical Technology

Background:

• Ablative infrared lasers like Er:YAG, ErCr:YSGG, and Ho:YAG have limitations in optical fiber transmission or cause thermal side effects.
• Efficient laser delivery via optical fibers is crucial for minimally invasive surgical procedures.
• The need exists for lasers with good transmission and minimal thermal damage for diverse surgical applications.

Purpose of the Study:

• To evaluate the CTE:YAG laser's efficacy for soft and hard tissue ablation.
• To assess the CTE:YAG laser's optical fiber transmission capabilities.
• To investigate the thermal side effects associated with CTE:YAG laser tissue interaction.

Main Methods:

• Investigated laser-tissue interaction on soft (porcine and human cornea) and hard (human dental) tissues.
• Utilized light microscopy and scanning electron microscopy for histological and micromorphological examinations.
• Measured ablation rates and collateral thermal damage at varying laser fluences and delivery modes.

Main Results:

• CTE:YAG laser demonstrated efficient optical fiber transmission (< 8db/m).
• Corneal ablation rates increased with laser fluence (5-90 microns/pulse), with thermal damage of 20 +/- 5 microns.
• Dental tissue ablation showed minimal increase in rate (1-3 microns/pulse) with higher fluences, accompanied by plasma luminescence.

Conclusions:

• The CTE:YAG laser is effective for laser surgery requiring high-power optical fiber delivery.
• Low thermal side effects make it suitable for applications where tissue damage is a concern.
• This laser presents a promising alternative to existing infrared lasers for various surgical procedures.