Effect of diode laser (980 nm) on <scp>IL</scp>‐8 expression in failed endodontic cases: Randomised control trial

This clinical study assessed the effectiveness of diode laser-980 nm as adjuvant in retreatment of failed endodontic cases with chronic periapical lesions on basis of IL-8 expression and postoperative pain when compared to placebo. For 28 patients, the pre-instrumentation periapical samples (S1) were gathered, following retreatment. After chemo-mechanical preparation, post-instrumentation samples (S2) were collected. Patients were allocated to diode laser (DL) or placebo (PL) groups. After which post-irradiation samples (S3) were gathered. Patients recorded their pain on NRS scale at 6, 12, 24 and 7 days. After 1 week, samples (S4) were collected. An ELISA kit was used to measure an amount of IL-8. DL group showed significantly lower IL-8 levels at S4 (p < 0.001) and postoperative pain at 6 h (p = 0.003) compared to PL. Intracanal diode laser irradiation is a beneficial adjunct to endodontics, in retreatment cases regarding reducing postoperative pain and lowering the level of IL-8 expression.