The inflammatory diseases of gingiva and periodontium, as well as their symptoms and the etiologic agents of these conditions (microbial plaque/biofilm) can be assessed clinically using qualitative and/or quantitative indices. In most instances, indices are used in epidemiologic studies, but they can also be useful during clinical examination of individual patients.
Indices are expressed numerically to describe defined diagnostic criteria: A disease process or its severity is described or classified using numbers (1, 2, 3 etc.). Simple indices record only the presence or absence of a symptom or an etiologic agent with “yes or no” entries, e.g., after sulcus probing: (+) = “bleeding,” (−) = “no bleeding.”
An appropriate index permits quantitative and qualitative statements about the criteria under investigation (disease, disease etiology), and is simple, objective, reproducible, rapid and practical. It should also be amenable for use by auxiliary personnel. Indices must provide data that are amenable to statistical evaluation.
Although indices for the most part were developed for epidemiologic studies, international standardization among various research groups has proven to be impossible: Many investigators use various indices or employ no indices whatever in periodontitis studies, rather they collect data on pocket probing depth and/or attachment loss in millimeters, which are then attributed to certain degrees of severity. Severity grades I–III: for probing depths up to 3 mm (I), between 4 and 6 mm (II) and those of 7 mm and greater (III). Other epidemiologists may assess these three severity grades using different millimeter measurements. Therefore it is scarcely possible to precisely compare the results of various studies to each other. Nevertheless, approximate conclusions can be drawn, e.g., concerning the worldwide incidence of periodontitis (p. 75).
Indices are also used in the private practice with individual patients: Especially plaque and gingivitis can be readily assessed in numerical fashion.
Repeated determination of an index during the course of preventive or active therapy can help ascertain the degree of patient motivation/compliance and treatment success or failure.
In this chapter, only a few of the many indices will be briefly described, primarily those which have been used for international epidemiologic studies, as well as some that are indicated for use on individual patients in private practice.
Plaque index (PI)—O’Leary et al. 1972
Approximal plaque index (API)—Lange 1986
Plaque index (PI)—Silness & Löe 1964
Bleeding on probing (BOP)—Ainamo & Bay 1975
Papilla bleeding index (PBI)—Saxer & Mühlemann 1975
Gingival index (GI)—Löe & Silness 1963
Periodontal disease index (PDI)—Ramfjord 1959
Community periodontal index of treatment needs (CPITN)—WHO 1978
Periodontal screening and recording (PSR)—ADA/AAP 1992
“Gingival Recession Index”
Recession is measured in mm from the cementoenamel junction to the gingival margin (Jahnke et al. 1993, p.162) or classified according to Miller (1985, pp. 162–163).
Papilla Bleeding Index—PBI
The PBI was developed for use in the private practice and not for epidemiologic studies. It is a sensitive indicator of the severity of gingival inflammation in individual patients. The PBI does not require a great amount of time, since only 28 measurement sites in the complete dentition are evaluated (Saxer & Mühlemann 1975).
The PBI has proven to be particularly useful for assessing inflammation in the interdental papillae by recording bleeding on probing in the interdental areas during the course of treatment. The index therefore offers an excellent means for patient motivation (p. 222). While the patient watches in a mirror, the practitioner can score the intensity of papillary inflammation. The patient can see when the gingival tissue bleeds, which helps him to realize where the diseased sites in the mouth are located.
The patient will realize and experience the reduction in inflammation during the course of therapy as the index is repeated at each visit, and this is a good motivator for thorough and continuing patient compliance.
Recording the PBI
Bleeding is provoked by sweeping the sulcus using a blunt periodontal probe under light finger pressure from the base of the papilla to its tip along the tooth’s distal and mesial aspects. After 20–30 seconds, when a quadrant has been completely probed, the intensity of bleeding is scored in four grades and recorded on the chart.
The sum of the recorded scores gives the “bleeding number.” The PBI is calculated by dividing the bleeding number by the total number of papilla examined.