Effects of root surface debridement using Er:YAG laser versus ultrasonic scaling - a SEM study.

ABSTRACT

OBJECTIVE: Despite promising results of ErYAG laser in periodontal debridement, to date there is no consensus about the ideal settings for clinical use. This experimental clinical trial aimed to determine the effects of debridement using ErYAG laser and to compare with ultrasonic treatment. MATERIALS AND METHODS: Sixty-four teeth were divided into two in vivo and in vitro subgroups. Each tooth received ultrasonic treatment on one side and ErYAG laser debridement at either 60, 100, 160 or 250 mJ pulse(-1) and at 10 Hz on the other side on a random basis. All samples were morphologically analyzed afterwards under scanning electron microscope for surface changes and dentinal tubules exposure. Treatment duration (d) was also recorded. RESULTS: Laser debridement produced an irregular, rough and flaky surface free of carbonization or meltdown while ultrasound produced a relatively smoother surface. The number of exposed dentinal tubules (n) followed an energy-dependent trend. The number of exposed tubules among the in vivo laser groups was n 60 mJ = n 100 mJ < n 160 mJ < n 250 mJ (P < 0.001). Also 160 and 250 mJ lasers led to significantly more dentinal exposure than ultrasound under in vivo condition. Within the in vitro laser groups, dentinal tubules exposure was n 60 mJ < n 100 mJ < n 160 mJ < n 250 mJ (P ≤ 0.0015). Furthermore, in vitro laser treatments at 100, 160 and 250 mJ led to significantly more dentinal denudation than ultrasound. Treatment duration (d) for the in vivo groups was d 60 mJ > d 100 mJ > d Ultrasound = d 160 mJ > d 250 mJ (P ≤ 0.046), while for the in vitro groups it was d 60 mJ > d 100 mJ = d Ultrasound = d 160 mJ >d 250 mJ (P ≤ 0.046). CONCLUSIONS: Due to excessive treatment duration and surface damage, ErYAG laser debridement at 60 and 250 mJ pulse(-1), respectively, is not appropriate for clinical use. Although laser debridement at 100 and 160 mJ pulse(-1) seems more suitable for clinical application, compared to ultrasound the former is more time-consuming and the latter is more aggressive. Using a feedback device or lower pulse energies are recommended when using laser in closed field.