CONNECTIVE-TISSUE RESPONSE TO ROOT SURFACES RESECTED WITH ND-YAG LASER OR BURS

Problem. The Nd:YAC laser beam may be used for root resection, but the tissue compatibility of the resulting root surface has not been confi rmed. Objective. This study assessed the connective tissue response ov er time to implanted root segments with Nd:YAC laser-cut or bur-cut su rfaces. Study design. Endodontically treated roots of 25 extracted hum an teeth were cross sectioned to form 3.5 mm thick disks by alternatin g a water-cooled Nd:YAG laser with a high-speed water-cooled tungsten fissure bur. A total of 63 disks were implanted into the dorsal subcut aneous tissue of 16 rats, then recovered with the surrounding tissue a fter periods of 3, 7, 14, 28, 60, and 90 days, and processed for light microscopic examination. Tissue against the cut surfaces was assessed for intensity and extent of inflammation and fibrous capsule thicknes s. Results. A two-factor analysis of variation showed statistically si gnificant (p < 0.05) differences between the laser-cut and bur-cut sur faces. Conclusion. Tissue repair about the root surfaces resected with Nd:YAC laser was delayed when compared with those resected with a bur .