“…The use of antibiotic treatment as adjunctive to non‐surgical periodontal therapy was initially introduced to tackle the microbial aetiology of periodontitis (Baer & Socransky, ) and later on more specifically with the main aim to eliminate periodontopathogenic bacteria (such as Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis ) which are otherwise likely to persist following mechanical biofilm removal only (van Winkelhoff et al, ). Adjunctive antibiotic treatment was initially restricted to patients with juvenile periodontitis (Lindhe & Liljenberg, ), but then sometimes also extended to patients with chronic, adult forms of periodontitis (Winkel, Winkelhoff, Timmerman, Velden, & Weijden, ) and/or to diabetic patients with periodontitis (Grellmann, Sfreddo, Maier, Lenzi, & Zanatta, ). The adjunctive use of systemic antibiotics has shown to be beneficial, especially but not exclusively in patients with aggressive periodontitis, in terms of improvements in clinical parameters (probing pocket depths, PPD, and clinical attachment levels, CAL) compared with placebo (Haffajee, Socransky, & Gunsolley, ; Herrera, Sanz, Jepsen, Needleman, & Roldán, ; Jepsen & Jepsen, ; Sgolastra, Petrucci, Gatto, & Monaco, ; Smiley et al, ; Zandbergen, Slot, Niederman, & Weijden, ), although the long‐term stability of such improvements is probably highly influenced by the supportive periodontal therapy regime adopted (Ramberg et al, ).…”