What exactly distinguishes aggressive from chronic periodontitis: is it mainly a difference in the degree of bacterial invasiveness?

At the International Workshop for Classification of Periodontal Diseases and Conditions in 1999, the classification of aggressive and chronic periodontitis that is presently used was introduced. A literature review of papers published in 2015 and having aggressive periodontitis in the title revealed that most studies use this terminology but it is questionable whether all established criteria were really applied correctly. Review of the literature showed no qualitative differences between aggressive and chronic periodontitis regarding bacterial and viral aspects. It is also unlikely that that there are major immunologic differences between aggressive and chronic periodontitis. Neutrophil function can be compromised in both conditions but may be more genetically related in aggressive periodontitis and be associated more with lifestyle factors in chronic periodontitis. In general, genetics plays a more important role in aggressive periodontitis than in chronic periodontitis. It is likely that periodontitis progresses by recurrent acute episodes during which invasion of bacteria into the connective tissue may occur. Two cases are presented for which invasive periodontitis is treated with systemic antibiotics, showing remarkable periodontal healing in terms of probing attachment gain, as well as radiographic bone gain. Periodontitis in an active state with bacterial invasion is probably accompanied with a significant increase in subgingival temperature. It is hypothesized that elevated subgingival temperature may help to distinguish between bacterial and nonbacterial invasive periodontitis. Scaling and root planing during a burst of disease activity may result in removal of connective tissue fiber attachment and down-growth of epithelium, thereby preventing the reattachment of connective tissue. Because the burst of disease is accompanied by an increase of temperature, assessment of the temperature may help in deciding whether or not to prescribe systemic antibiotics. When the use of systemic antibiotics is indicated, the antibiotic therapy may help to maintain the connective tissue attachment at the most possible coronal level. The above implies that the ability to diagnose bacterial invasive periodontitis is quite important, and future research is needed to determine if assessment of subgingival temperature may help in diagnosing invasive periodontitis. In addition, it is suggested that future classification systems of periodontitis include the item of bacterial invasive periodontitis.