Purpose: The aim of the present study was to evaluate the tissue retraction and gingival healing in pulsed laser (diode 980 nm and Nd:YAG 1064 nm lasers) gingival retraction in comparison with the conventional mechanical or surgical techniques (double cord and electrosurgery). Materials and Methods: A group of 103 adult patients, 45 women, 58 men (mean age 42, range 19 to 52 years) scheduled for fixed and implant prosthetic rehabilitation was recruited, and four impression techniques were compared: the double cord technique, the electrosurgery technique, the 980-nm diode and the 1064-nm Nd:YAG laser technique. Patient were randomly placed into four groups according to impression-taking technique. Thirty impressions were taken in each group, for a total of 110 elements each. The preferred impression materials were addition silicones (polyvinyl siloxanes) (2nd generation). The outcome was measured by the bleeding index (during the impression taking and after 15 days) and gingival retraction (after 15 and 30 days). Results: Compared to the conventional techniques, both laser techniques proved to be less aggressive in terms of absence of gingival bleeding (99.2% vs 92.7%). There were also fewer cases of gingival retraction than with the conventional technique (2.2% vs 10%). Conclusion: This study suggests that the laser technique can be valuable for implant prosthetic rehabilitation. While both the conventional and laser techniques are satisfactory in achieving gingival retraction, the laser techniques may be less traumatic to the periodontal tissue.
Keywords: impression techniques, diode 980 nm laser, Nd:YAG laser, electrosurgery, polyvinyl siloxanes, gingival retraction, oral soft tissue surgery