1. Classifying periodontal diseases â a long-standing dilemma;Armitage;Periodontology,2002
2. Development of a classification system for periodontal diseases and conditions;Armitage;Ann. Periodontol.,1999
3. [3] Marsh, P. and Martin, M.V. (1999) Oral Microbiology, 4th edn. Wright, Boston, MA.
4. [4] Loesche, W.J. and Laughon, B. (1982) Role of spirochetes in periodontal disease. In: HostâParasite Interactions in Periodontal Disease (Genco, R.J. and Mergenhagen, S.E., Eds.), pp. 62â75. American Society for Microbiology, Washington, DC.
5. The diversity of periodontal spirochetes by 16S rRNA analysis;Dewhirst;Oral Microbiol. Immunol.,2000