Clinical benefits of systemic amoxicillin/metronidazole may depend on periodontitis stage and grade: An exploratory sub-analysis of the ABPARO trial

Eickholz P.; Koch R.; Göde M.; Nickles K.; Kocher T.; Lorenz K.; Kim T.S.; Meyle J.; Kaner D.; Schlagenhauf U.; Harks I.; Ehmke B.

Abstract

Aim: Assessment of treatment response after systemic amoxicillin/metronidazole adjunctive to subgingival instrumentation (SI) according to stages and grades of the 2018 classification of periodontal diseases. Materials and Methods: We carried out exploratory re-analysis of the placebo-controlled, multi-centre ABPARO trial (52; 45/60 years of age; 205 males, 114 active smokers). Patients were randomized to SI with systemic amoxicillin 500 mg/metronidazole 400 mg (three times a day for 7 days, n = 205; ANTI) or placebo (n = 200; PLAC) and maintenance therapy every 3 months. Patients were reclassified according to the 2018 classification (stage/extent/grade). Treatment effect was the percentage of sites per patient with new attachment loss ≥1.3 mm (PSAL ≥ 1.3 mm) at 27.5 months post-baseline/randomization. Results: All patients were assigned according to the stage (n = 49 localized stage III, n = 206 generalized stage III, n = 150 stage IV). Because of missing radiographs, only 222 patients were assigned to grades (n = 73 B, n = 149 C). Treatment (PLAC/ANTI) resulted in PSAL ≥ 1.3 mm (median; lower/upper quartile) in localized stage III (PLAC: 5.7; 3.3/8.4% vs. ANTI: 4.9; 3.0/8.3%; p =.749), generalized stage III (8.0; 4.5/14.3% vs. 4.7; 2.4/9.0%; p