Although the findings differ for each antimicrobial and mode of delivery, the authors make some important overall observations relating to the key question. First, relative to the PD reductions achieved from the baseline measurement to the study end-point measurement, the difference in measurements between the treatment and control groups typically favored the treatment group, but was relatively modest. With respect to CAL gains, the picture was similar, but the effects are smaller and statistical significance was less common.
Of the antimicrobials investigated, studies of locally applied tetracycline and minocyclineand locally delivered chlorhexidinehave fairly consistent results in moderately large studies that often reach statistical significance; improvements observed in these studies typically average in the neighborhood of 0.3 mm to 0.6 mm. The other agents and delivery modes produced less consistent outcomes and fewer outcomes that reached statistical significance; the majority of studies showed small, statistically nonsignificant PD improvements. CAL outcomes were not as positive as those for PD. The question remains, the authors note, whether such improvements are clinically meaningful.