Читать книгу Basic Guide to Oral Health Education and Promotion - Alison Chapman - Страница 84

Subgingival calculus (Figure 2.5) is less obvious to the patient, and is found below the gum margin in periodontal pockets. It is often black, dark brown or green in colour and is formed when minerals from fluid (crevicular fluid) in the gingival crevice come into contact with plaque. (The dark colour is derived from the breakdown of blood constituents resulting from ulceration in the crevice.)

Subgingival calculus is often hard and difficult to remove. Its presence is much more significant than supragingival deposits as it indicates that periodontitis is present.

Figure 2.5 Subgingival calculus exposed after improved oral hygiene.

Source: Mary Mowbray. Reproduced with permission of Mary Mowbray.