Abstract
A summary of the major highlights of periodontal pathogenesis research with particular emphasis on periodontal microbiology is presented. Bacteriologic specificity, periodontal disease activity, anatomical plaque research, bacterial recolonization and the concept of bacterial succession are discussed. Periodontal immunology, gingival fluid, histopathology as well as clinical research are briefly mentioned as they interrelate with periodontal microbiology.