英语论文网

is as though with the development of the pocket the disease has gone underground.
     The presence and severity of gingival inflammation depends upon oral hygiene status; where this is poor, gingival inflammation is evident and bleeding of brushing, or even spontaneous bleeding, is noticed by the patient. When the patient' s toothbrushing is good enough to control plaque but where subgingival deposits, because of inadequate scaling, persist, the presence of periodontal disease may not be apparent on superficial examination. If a careful history is taken many such patients report a history of past bleeding which stopped when their toothbrushing technique improved. Periodontal destruction in the average adult is the product of past neglect, not
the result of present oral hygiene habits.

     Pocketing
     Pocket measurement is an essential part of periodontal diagnosis but must be interpreted together with gingival inflammation and swelling and radiographic evidence of alveolar bone loss.     Theoretically, if there is no gingival swelling a pocket over 2 mm deep indicates some apical migration of crevicular epithelium but inflammatory swelling is so common especially in the younger individual that pocketing of 3-4mm may be entirely gingival or ‘false’. Pocketing of 4mm is likely to indicate an early chronic periodontitis.
     The precise measurement of pockets is difficult because:
     1. Probing the pocket can be uncomfortable and even painful if there is frank inflammation.
     2. Pocket depth is extremely variable around a tooth. Interproximal pocketing is usually deepest because that is the site of greatest plaque accumulation, while pocketing on the facial aspect of the tooth is usually most shallow as this is where the toothbrush makes the greatest impact and may even produce gingival recession. This means that four or more measurements may be required on each tooth to give an accurate picture.
     3. Where present oral hygiene is good the gingival cuff may be so tight around the neck of the tooth as to resist the insertion of an ordinary periodontal probe without causing pain. The measurement of pockets in anaesthetized tissue often produces quite different results from previous measurement made in sentient tissue.
     4. Tooth contour and angulation, subgingival calculus or restorations, as well as carious cavities, may impede the insertion of the probe.
     There are many designs of pocket-measuring probe, some of, which are too thick to provide accurate measurement and some of which are sharp so that the tissue is penetrated unless great care is taken. It has been shown that pockets of over 3mm are measured with diminishing reliability, and it is unfortunate that much periodontal research is based upon such an unreliable criterion. Sometimes a purulent discharge can be expressed from the pocket by pressure on the pocket wall.

     Gingival recession
     Gingival recession and root exposure may accompany chronic periodontitis but are not necessarily a feature of the disease. Where recession occurs pocket depth measurement is only a partial representation of the total amount of periodontal dest