The scientific basis of periodontal treatment.

The development of periodontal treatment based on knowledge of the aetiology and pathogenesis of the diseases is reviewed. Emphasis is laid on the role of microorganisms and especially on the significance of their immunological interactions with the host. It is concluded that, despite increasing knowledge of the pathogenesis, microbiology and immunology of periodontal diseases, the methods of treatment have not changed essentially during the past 30 years. Oral hygiene instruction, scaling and root planing are still the methods of choice.