Scanning electron microscope evaluation of morphological changes in dental hard tissue after root resection in apicoectomy by Er,Cr:YSGG laser and #702 TC Bur: Part I

Abstract

Aim: The aim of this study was to compare surface characteristics and morphological changes in Er,Cr:YSGG laser and bur resected root ends in apicoectomy. Settings and Design: 5 W, 20 Hz, 50% air, 100% water, 300 mJ. Materials and Methods: Forty freshly extracted human central incisors treated endodontically. gutta-percha-obturated teeth were resected apically 3 mm with 0° bevel. Twenty samples were resected with #702 TC Bur while rest half were resected with Er,Cr:YSGG laser with 600 μm sapphire tip. Samples were examined for cemental damage, surface roughness, and cracks under surgical operating microscope (SOM) 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/Fisher′s exact test, Kruskal-Wallis test, whenever required. Results: Under SOM, no cemental damage was detected; while under SEM, 14 bur and 1 laser resected samples exhibited damage (P < 0.001). Under SOM and SEM, bur resected surface showed roughness in 17 and 20 samples, respectively, while laser resected surface appeared to be smoother in 18 and 19 samples, respectively (P < 0.001). Under SOM, cracks seen in only 1 bur resected sample, while in laser resected samples, no cracks revealed. Under SEM, bur root resection revealed cracks in 16 samples; laser root resection revealed cracks in 3 samples (P < 0.001). Conclusions: Er,Cr:YSGG laser resection as compared to #702 TC Bur resection exhibits less damage to cementum, smoother dentinal surface with least or no surface cracks/microcracks.