Response of associated oral soft tissues when exposed to Argon laser during polymerization of dental resins

Polymerization of dental resins with Argon laser produces restorations with improved physical properties when compared to conventional visible-light polymerization techniques. However, the possibility of damaging adjacent soft tissues has not been addressed.

In this study, Argon laser (488/514 nm) was used for the polymerization of composite resins to determine effects on the parakeratinized gingiva adjacent to both restored and unrestored teeth in six dogs, using 10-, 20-, and 30-second polymerization exposures.

Gingival tissues removed at 24 hours, 72 hours, or 5 days revealed desiccated, disrupted, hyalinized connective tissue. Tissues exposed for 10 seconds showed minimal change. This minimal degree of change was most evident at 72 hours and returned to normal limits at 5 days. The 20-second exposure produced alterations evident through all time periods. Tissues exposed for 30 seconds exhibited necrosis, severe disruption, and vessiculation, which was still unresolved at 5 days.

This study demonstrates that clinically relevant Argon laser exposure (10 seconds) of parakeratinized gingiva adjacent to teeth undergoing restoration does not cause lasting damage.