“…For probing pocket depth values up to 3 mm, 4–43% of the root surface was still covered with remnants of plaque or calculus after thorough instrumentation (42, 44, 58, 75, 164). In pockets with a probing pocket depth of 4–6 mm, 15–38% of the instrumented root surface still demonstrated the presence of calculus or plaque (42, 44, 47, 58, 75, 108, 164). In pockets deeper than 6 mm, these values varied between 19 and 66% (13, 42, 44, 47, 58, 75, 108, 118, 164).…”