Chronic periodontitis is one of the seven categories of periodontitis as defined by the American Academy of Periodontology 1999 classification system. Chronic periodontitis is a common disease of the oral cavity consisting of chronic inflammation of the periodontal tissues that is caused by the accumulation of profuse amounts of dental plaque. Periodontitis initially begins as gingivitis and can progress onto chronic and subsequent aggressive periodontitis according to the 1999 classification. Diagnosing chronic periodontitis is important in its early stages to prevent severe and irreversible damage to the protective and supportive structures of the tooth. However, due to chronic periodontitis being a painless progressing disease, few patients will seek dental care in the early stages. Mild to moderate chronic periodontitis can be managed by proper mechanical removal of the biofilm and calculus subgingivally. Full and effective oral hygiene and regular 3 monthly periodontal checkups are important for maintaining the stability of the disease. Chronic periodontitis is prevalent in adults and seniors worldwide. In the US around 35% of adults (30–90 years) are affected. The cumulative effects of alveolar bone loss, attachment loss and pocket formation is more apparent with an increase in age.
Whilst there is evidence that GTR can demonstrate a significant improvement over conventional open flap surgery, the factors affecting outcomes are unclear from the literature and these might include study conduct issues such as bias. Therefore, patients and health professionals need to consider the predictability of the technique compared with other methods of treatment before making final decisions on use." Enamel matrix derivative
Enamel matrix derivative (EMD) is favoured by some practitioners despite its high cost:  "One year after its application, EMD significantly improved probing attachment levels (1.1 mm) and probing pocket depth reduction (0.9 mm) when compared to a placebo or control, however, the high degree of heterogeneity observed among trials suggests that results have to be interpreted with great caution. In addition, a sensitivity analysis indicated that the overall treatment effect might be overestimated. The actual clinical advantages of using EMD are unknown. With the exception of significantly more postoperative complications in the GTR group, there was no evidence of clinically important differences between GTR and EMD. Bone substitutes may be associated with less gingival recession than EMD. "However, studies have shown that regardless of the conventional periodontal treatments, 20-30% of chronic periodontitis patients do not respond favorably to their treatment. There are many factors which account for these including: ineffective removal of calculus, defective restorations, impaired immune response as a result of a systemic condition, poor plaque control, smoking, etc. Adjunctive systemic antibiotic treatment
Systemic antibiotics such as amoxicillin or metronidazole are sometimes used in addition to debridement based treatments.