Farmacologia

Periodontology 2000, Vol. 36, 2004, 146–165 Printed in Denmark. All rights reserved

Copyright Ó Blackwell Munksgaard 2004

PERIODONTOLOGY 2000

Chemotherapeutics: antibiotics and other antimicrobials
C L A Y B. W A L K E R , K A T H E R I N E K A R P I N I A & P I E R R E B A E H N I

Comprehensive treatment of periodontitis is very different from the treatment of most bacterialinfections. While periodontitis is traditionally considered a bacterial infection, many variables influence treatment outcomes. These include systemic factors, psychological influences, diet, genetic and ⁄or intrinsic individual attributes, and environmental circumstances. Bacterial flora within the periodontal pocket exist in a complex heterogeneous biofilm that is incongruous from individual to individualin both the species and the proportions present. Often, within an individual barely detectable differences exist in the cultivable flora associated with a clinically healthy site vs. an inflamed ⁄diseased site. Although a tremendous amount of effort has been expended over the past 30 years to elicit the causative agents of periodontitis, rarely has a single bacterial species been directly linked toperiodontal diseases as its single etiologic factor. There is currently strong enough evidence to implicate three microorganisms as etiologic agents of periodontal diseases. An abundance of literature clearly indicates Actinobacillus actinomycetemcomitans is most often associated with aggressive juvenile periodontitis. Currently, A. actinomycetemcomitans remains the sole periodontal bacteriumremotely close to satisfying Koch’s postulates for identifying an etiologic agent of disease. Although the evidence is not as extensive, there is also sufficient data to consider Porphyromonas gingivalis and Tannerella forsythia as etiologic agents for periodontal diseases. The presence of either P. gingivalis or T. forsythia, especially in high proportions in progressive lesions, serves as a strongtreatment indicator. The presence of any one of these three bacteria is considered undesirable and may place an individual at risk for disease progression. Periodontitis can and does occur in the absence of any of the aforementioned three identifiable periodontal pathogens. Associative evidence has linked a

number of different bacterial species with destructive disease. Prevotella intermedia,Fusobacterium nucleatum, Eikenella corrodens, Campylobacter rectus, Eubacterium nodatum, Peptostreptococcus micros, and various spirochetes have all been implicated as etiologic agents in periodontal diseases, although evidence for their causative role is less clear. Unfortunately, neither the identity of the causative organism(s) nor the microbial susceptibility to an antimicrobial agent are readilyavailable to the periodontal practitioner. Therefore, treatment with or without adjunctive antimicrobial agents is largely based upon somewhat ambiguous clinical parameters. The vast majority of periodontitis cases respond well to conventional nonsurgical periodontal therapy, i.e. scaling and root planing (SRP), improved oral hygiene and supportive periodontal recall. However, certain patients,for various reasons, do not respond favorably to mechanical therapy alone. For these patients, the use of an appropriate adjunctive antimicrobial is often beneficial. Two questions arise. First, how does the practitioner recognize patients who will benefit from adjunctive antimicrobial therapy? Second, which antimicrobial agent is most likely to provide the beneficial response desired with minimaladverse effects?

The nature of the bacterial challenge
Most periodontal investigators agree that bacteria are the primary etiologic agents of destructive periodontal diseases, although there is some recent evidence that implicates certain viral agents (13, 14, 73, 110). Such viruses, e.g. cytomegalovirus, Epstein–Barr virus, papillomavirus, and herpes simplex virus, may have a role in the...