apples) (though this may occur even in gingivitis, where there is no attachment loss)
Gum swelling that reoccurs
Halitosis, or bad breath, and a persistent metallic taste in the mouth
Gingival recession, resulting in apparent lengthening of teeth. (This may also be caused by heavy-handed brushing or with a stiff tooth brush.) Deep pockets between the teeth and the gums (pockets are sites where the attachment has been gradually destroyed by collagen-destroying enzymes, known as collagenases)
Loose teeth, in the later stages (though this may occur for other reasons as well)
Drifting of incisorsGingival inflammation and bone destruction are often painless. Patients sometimes assume that painless bleeding after teeth cleaning is insignificant, although this may be a symptom of progressing chronic periodontitis in that patient. Subgingival calculus is a frequent finding as well as supragingival calculus due to the bacteria migrating apically and the combined effect of the host response system of the body. Diagnosis
1999 classification
Chronic periodontitis is one of the seven destructive periodontal diseases as listed in the 1999 classification. Not every case of gingivitis will progress onto chronic periodontitis, but all chronic perodontitis results from gingivitis. Therefore it is important to control the first step; gingival inflammation. A difficulty which arises with diagnosing chronic periodontitis patients is due to the slow and painless progression of the disease. The most effective and timely diagnosis would be during the mild to moderate stage. However, usually when presenting complaints do arise the effects of mobility and alveolar bone loss have become severe.
A full mouth examination and recording is required to document and track periodontal disease including:

Pocket Depth (PD)
Clinical Attachment Loss (CAL)
Bleeding On Probing (BOP)
Plaque index/score
Furcation involvement
Suppuration
Mobility
RadiographsMeasuring disease progression is carried out by measuring probing pocket depth (PPD) and bleeding indices using a periodontal probe. Pockets greater than 3mm in depth are considered to be unhealthy. True pocket formation of 4 mm or more are specifically related to chronic periodontitis. Bleeding on probing is considered to be a sign of active disease. Discharge of pus, involvement of the root furcation area and deeper pocketing may all indicate reduced prognosis for an individual tooth. Evidence of alveolar bone loss is also required to differentiate between true bone loss and not attributions of gingival oedema. Usually, a horizontal pattern of bone loss would be found however, vertical (infrabony) bone loss may also be present on specific sites. A Basic Periodontal Examination (BPE) or Periodontal Screening and Recording (PSR) should give a score of 3 or 4. A correct diagnosis is vital to allow the formation of a specific treatment plan for the patient and to arrest the disease progression. Chronic periodontitis can be further classified into:

Extent (can be either localised affecting < 30% of sites; or generalised if > 30% of sites are affected)
Severity (slight = 1–2 mm CAL; moderate = 3–4 mm CAL; severe ≥5 mm CAL)

2017 classification
Chronic periodontitis is not included within the newer 2017 World Workshop classification.