Should I prescribe a script of antibiotics (only — without debridement) when I see a patient of periodontal abscess?
The plaque is a biofilm, which means:
There are distinctly different microcolonies of micro-organisms (more than bacteria) live together
They co-operate for survival of colony
by metabolic interexchange i.e. substance P is used by bacteria A and produce substance Q nourishes bacteria B.
by producing extracellular matrix that protects colony (biofilm) against host response (lymphocytes, PMN, monocytes, antibodies, etc.) and also antibiotics and antiseptic solution.
Bacteria within colony have messenger system for communication and also exchange genetic materials which can be antibiotic resistance gene. For example, a nasty antibiotic resistance gene NDM-1 can transfer from a good bacteria of normal flora to a highly virulent species. When the gene was with good bacteria, it did not harm the host; but will harm when the highly virulent species acquires it — it is harder to treat this species with antibiotics subsequent to genetic exchange
Bacteria within colony (biofilm) produces substances to defend survival of the colony. as an example, if streptococci within biofilm are able to produce penicillinase or beta-lactamase, they can protect other virulent organisms against the effect of penicillin.
Structure of Biofilm in laboratory
Treating bacteria with antibiotics is not simple when they are within biofilm. Effective concentration of antibiotics need to be at least 500 to 1000 times higher than the minimal bactericidal concentration required for planktonic bacteria. It is not possible to achieve this concentration using systemic antibiotics without avoiding toxic effects.
Well designed randomised split mouth studies suggested that even combination antibiotics like Amoxicillin and metronidazole without debridement are not as effective as systematic periodontal debridement without antibiotics. Periodontal debridement is aimed at destroying the biofilm structure, so antibiotic concentration subsequent to this disruption of biofilm makes more sense and is also evident in series of studies. thus, antibiotics given as a script without debridement is not likely to work on plaque.
Periodontal abscess is an acute exacerbation of chronic inflammatory process which is triggered by blocking of the pocket opening. Disruption of biofilm is essential. With monotherapy of antibiotics (script only), there may be short-term subsidence of swelling but pockets do persist with bacteria harder to treat with possible recurrent periodontal abscess! Antibiotics in case of periodontal abscess should only be considered as an adjunct only if:
There are signs of systemic dessipation of bacterial infection i.e. fever, malaise with or without lymphadenopathy
Severely immuno-compromised individuals.
If not, prescribing antibiotics is not necessary in cases of periodontal abscess, or even ANUG (acute necrotizing ulcerative periodontitis). Just thorough subgingival debridement is sufficient.