Non-vital bleaching produces a positive and stable impact on the esthetic perception and psychosocial factors at medium-term follow-ups.

The technique of walking bleaching was highly effective and showed minimal color rebound in nonvital teeth and had a positive effect on patients' psychological impact at the one-year follow-up.

Objective: This study assessed IL-1β and RANK-L levels in vivo and color stability of non-vital teeth bleached using hydrogen (35%) and carbamide (37%) peroxides 3 months after treatment. Materials and Methods: Fifty teeth were randomly divided into two groups (n = 25):35% hydrogen peroxide (HP) or 37% carbamide peroxide (CP). Four sessions of intracoronal walking-bleach procedure were performed. IL-1β and RANK-L levels were assessed from gingival crevicular fluid samples (from three vestibular and three palatines sites) at eight different time-points: at the beginning of the study (baseline), after four sessions of intracanal bleaching, and at 1 week, 1 month, and 3 months posttreatment. The color variations were visually detected using Vita bleach shade guide (ΔSGU). Results: Significant increases of IL-1β and RANK-L levels were detected at all timepoints (all P < .05) when comparing each time-point to baseline, and a high correlation (>0.8-Spearman) between variables. According the ΔSGU values, a color change of five for HP and four for CP were detected. Conclusions: Non-vital walking bleach technique promotes an increase in IL-1β and RANKL levels in periodontal tissues and also, it is maintained until the third-month posttreatment. Clinical Significance: The internal whitening of teeth increases the levels of cytokines associated with inflammation and bone resorption 3 months after the whitening procedure is finished; this should warn of possible harmful effects of this whitening technique. K E Y W O R D S biomarkers, double-blind study, hydrogen peroxide, RANK-L, tooth bleaching

Lately, the use of laser in endodontics has gained acceptance, being considered as a complement to endodontic therapy, which aims to carry out an effective shaping, cleaning and disinfection of the root canal system (RCS), allowing an effective elimination of microorganisms present, and thus prevent reinfection of the canal. Different laser application methods have been adopted to improve the disinfection of the RCS, which could be effective in reducing the microbial population present inside the canals, by activating the irrigant used. The use of laser could also be useful in surgical endodontic procedures which aim to maintain the tooth and its roots when conventional treatment has failed, the positive effects of laser would focus on reducing inflammation and increasing volume, in addition of the reduction in the filtration of orthograde seal materials in apicoectomized teeth. Another use of laser in this area is related to post-endodontic therapy pain management, which has shown promise. Two types of lasers are defined; low-power, which produces a biostimulant, analgesic and anti-inflammatory action of biological tissues, also used in RCS decontamination processes, and high-power or surgical laser, with which incisions, excision, performing cutting functions and coagulation.