Scanning electron microscope evaluation of morphological changes in dental hard tissue after root resection in apicoectomy by erbium, chromium:yttrium-scandium-gallium-garnet laser and #702 TC Bur: Part II

Abstract

Context: In Part I of this in vitro SEM study, we have discussed the effect of root resection tools on root end in terms of Cemental damage, Dentin Surface texture and Dentinal Cracks. This part (Part II) will focus on effect of root resection tools on root end in terms of Debris, smear layer, Dentinal tubules, Intertubular Dentin and Root Dentin - Gutta percha interface. Aims: To compare surface characteristics and morphological changes in erbium, chromium:yttrium-scandium-gallium-garnet (Er;Cr:YSGG) laser and bur-resected root ends in apicoectomy. Settings and Design: 5 W, 20 Hz, 50% air, 100% water, 300 mJ. Subjects and Methods: Forty freshly extracted human central incisors treated endodontically. Gutta-percha (GP) obturated teeth were resected apically 3 mm with 0° bevel. Twenty samples were resected with #702 TC Bur while the rest half were resected with Er,Cr:YSGG laser with 600 µm sapphire tip. All the samples were examined for debris, smear layer dentinal tubules, intertubular dentin and interface of GP, and root dentin on resected root surface under surgical operating microscope at ×16. Then, samples were fixed, dehydrated, and gold sputtered for observation under scanning electron microscope (SEM). Statistical Analysis Used: Data obtained were subjected to statistical analysis using Chi-square/Fischer exact test whenever required. Results: SEM observation revealed the absence of debris and smear layer with clean cut surface and patent dentinal tubules with exposed intertubular collagen, less gap (mean 9.95 µm), and least damage to apical adaptation of GP to root dentin walls in Er,Cr:YSGG-laser-resected root surface; while bur-resected samples revealed irregular, rugged root surface covered with debris, smear layer clogged dentinal tubules more gap (mean 20.98 µm) and damage to interface at GP, and root dentin walls. Conclusions: Er,Cr:YSGG-lased root surface provides better surface morphology, more conducive surface for regeneration of periodontium as compared to bur root resection.