Pulpal effects of enamel ablation with a microsecond pulsed lambda = 9.3-microm CO2 laser

Area of Science:

• Dental Laser Technology
• Biomedical Optics
• Tooth Histology

Background:

• CO2 lasers at 9.3/9.6-microm wavelengths show promise for enamel and dentin ablation.
• FDA approval is pending; clinical data on pulpal safety is needed.
• Investigating thermal effects on the pulp at higher fluencies is crucial.

Purpose of the Study:

• To evaluate the pulpal safety of CO2 laser irradiation on tooth occlusal surfaces.
• To assess safety under conditions for conservative enamel preparations.
• To determine potential detrimental pulpal effects from heat deposition.

Main Methods:

• Pulsed CO2 laser (9.3 microm) used on third molars scheduled for extraction.
• Irradiation at 25/50 Hz, 20 J/cm(2) fluence with water cooling.
• Histological examination of pulpal tissues and micro-thermocouple measurements of pulp chamber temperature.

Main Results:

• Pulp chamber temperature rise was minimal (1.7+/-1.6°C with water cooling).
• No deleterious effects on pulpal tissues observed in any group.
• No patient-reported pain or discomfort, except for transient cold sensitivity.

Conclusions:

• CO2 laser ablation of enamel is safe for dental pulp under tested conditions.
• The energy deposition rate employed did not harm pulpal tissues.
• Further clinical studies may support laser use for conservative dental preparations.