title: Periodontal inflammation and attachment loss: a critical problem for biological studies.
abstract: BACKGROUND
  In biological studies of periodontitis, there has been long-standing confusion between the ubiquitous phenomena of inflammation and the essential criterion of attachment loss. This is partly attributable to inadequate methods of clinical measurement, but seems also to be a consequence of an unproven and usually unstated assumption that the same biological processes underlie both inflammation and attachment loss. Developments in unidimensional clinical probing methods have helped in studies of periodontal treatment. However, such methods are intrinsically unsuitable in studies of periodontal diseases, and may have given them a false sense of security. the confusion has been compounded by inappropriate use of statistical techniques in an attempt to solve problems which do not arise from mathematical models but are intrinsic to measurement methods.
  
  
  OBJECTIVE
  This paper is a clinician's attempt to state the current difficulties and suggest some ways forward, including the development of three-dimensional measurement, non-invasive probing, and several objectives for biochemical, microbiological and immunological research.
authors.affiliation: Department of Periodontology and Preventive Dentistry, United Medical and Dental Schools (Guy's Campus), London, UK.
authors.forename: T L
authors.initials: TL
authors.lastname: Watts
mesh_terms: D003627:Data Interpretation, Statistical; D018865:Dental Research / Q000379:methods; D018450:Disease Progression; D006801:Humans; D008297:Male; D017622:Periodontal Attachment Loss / Q000473:pathology*; D010518:Periodontitis / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D015203:Reproducibility of Results; D012107:Research Design