To the best of our knowledge, this is the first study that compared intra-pocket diode laser therapy (980 w) for one session with systemic antibiotic (combination of spiramycin and metronidazole) as adjunctive with SRP in stage III grade C periodontitis investigating the gingival crevicular levels of Aa and Pg in addition to clinical evaluation based on PPD, CAL. This evidence concerns the gene JUP and periodontitis.