• Anti-microbial, Antibiotic, Anti-infective: Pharmacological Co-Treatment

  • Host Factor Modulating Substances

Anti-infectious Supportive Therapy—Antibiotics in Periodontitis Therapy

The accumulation of bacteria upon the teeth represents the primary cause of gingivitis and periodontitis. The regular mechanical removal of plaque biofilm from all non-desquamating surfaces is therefore essential, and it is also the primary measure for prevention or inhibition of the progression of periodontitis (Mombelli 2003).

Through systematic, careful debridement of teeth and affected root surfaces, periodontitis can in many cases be successfully treated. Two disadvantages of this non-specific mechanical treatment, which is repeated regularly at recalls, are the irreversible and ever-increasing damage to tooth hard structure, especially roots within periodontal pockets, as well as gingival recession. In addition, it is virtually impossible to mechanically remove dental plaque from narrow grooves and scratches, narrow furcations and other bacterial reservoirs within the pocket area (p. 255).

Thus it is appropriate to combine mechanical plaque suppression with a medicinal, anti-infectious parallel therapy. Since only a few bacterial species are potentially periodontopathic, it is reasonable to eliminate these groups specifically (Mombelli, Slots, van Winkelhoff). These groups contain bacteria that can colonize cells of the pocket epithelium and thus escape both the host response and mechanical cleaning efforts (A. actinomycetemcomitans, P. gingivalis, S. constellatus; Herrera et al. 2002). This situation can be effectively combated using systemic antibiotics or topically-applied medicaments.

In addition to antimicrobial agents, mainly antibiotics with their well-known side effects and the ever-increasing emergence of resistant microbial stains, more and more new substances are being offered for use in periodontal therapy, especially agents that modulate the host response.

This chapter on “Medications” is arranged as follows:

  • Decision-making criteria—When to use antibiotics?

  • Systemic antibiotics for periodontitis therapy

  • Antibiotics—Bacterial sensitivity and resistance

  • Systemic versus topical antimicrobial treatment

  • Topical antimicrobial treatment—Controlled release drugs

  • Host response—modulating substances

p. 286

Which Pill is the Correct One?

Decision-Making Criteria—When to Use Antibiotics?

Remember: Periodontitis is an infectious disease, caused by periodontopathic, usually opportunistic microorganisms that are organized within a protective biofilm.

Both non-pathogenic and pathogenic species live every-where in the oral cavity, above all in niches of every sort. They construct a biofilm characterized by close community interrelationships, and exchange metabolic by-products, virulence factors, resistance factors etc. The biofilm protects against the host response as well as against antimicrobial pharmacologic agents (Haffajee et al. 2003).

Even though purely mechanical/instrumental treatment—surgical or non-surgical—will usually very much improve the clinical parameters in most cases, in certain situations an antimicrobial supportive therapy, applied systemically or topically, can improve the treatment outcome (Hung & Douglass 2002, Mombelli 2003).

Antibiotics help to subdue the infection; they do not affect healing. Only the host organism can do this. The sensitivity and the nature of the colonization will determine the choice of an antibiotic.

658 Medicinal Supportive Therapy—Yes or No? Severely progressive cases of chronic periodontitis/Type II, particularly periodontitis cases associated with compromised host response (aggressive periodontitis/Type III, and periodontitis with systemic diseases/Type IV etc.) require systemic supportive therapy in addition to mechanical/instrumental treatment. It is imperative that treatment failure not be caused by the patient’s own poor oral hygiene! The flow-chart depicted here shows a reasonable “decision tree.” The question always arises, whether and when are microbiologic tests indicated. Such tests provide better information about the necessity to employ systemic antibiotics against specific microbial pathogens. Additional tests after therapy can reveal whether or not the targeted microbial species have been eliminated.
659 Test Results—Example of the IAI PadoTest 4.5 On the basis of its affinity for pathogenic species Aa, Tf, Pg, and Td, this test (p. 185) defines five pocket types (clusters), and provides decision-making information about the use of antibiotics. Beyond the reduction of probing depths that can be achieved by improved oral hygiene alone, better clinical results usually follow scaling and root planing (S + RP), especially S + RP combined with a systemic antibiotic in types 4 and 5.

Microbiologic Testing

  • Tests before treatment define the pathogenic species, above all the presence of Aa and/or Pg, and provide a basis for selecting an antibiotic.

  • Tests after treatment show whether or not the maker bacteria have been eliminated.

Pooled Findings or Individual Findings?

With the use of systemic antibiotics, pooled findings are sufficient. However, if individual active residual pockets remain after treatment, the pooled findings provide no information about the initial status.

When Indicated: Which Antibiotic to Prescribe?

The spectrum of efficacy of antibiotics, their important side effects and the compliance of the patient must be understood in advance: Oral ingestion (tablets) over an extended period of time demands discipline from an informed patient (Newman & van Winkelhoff 2001).

In general, broad spectrum antibiotics (e.g., tetracyclines) are used only for special indications. While the commensal flora consists primarily of gram-positive aerobes, the periodontopathic organisms are mainly gram-negative and anaerobic.

660 Established and Frequently Employed Systemic Antibiotics for Supportive Periodontitis Therapy Medication class, average dosage and duration of medication are shown. In order to prevent the emergence of resistant bacterial strains, medication should never be prescribed with excessively low doses or short regimens! Bacteriocidal antibiotics (AB; “-cidal”) exert their effects much quicker than bacteriostatic (“-static”) agents. Bacteriocidal agents should never be given simultaneously with bacteriostatic antibiotics. On the other hand, the serial use of antibiotics (one-after-the-other, see combinations) may provide optimal effects (cf. varying treatment of HIV, p. 149): * Successive drug use: Penicillin → tetracycline ** Augmentin: Combination of amoxicillin (AB) and the penicillinase inhibitor clavulanic acid *** Rodogyl: Combination of metronidazole and spiramycin
661 Effect of Various Antibiotics and Antiseptics on the Target Organisms Bacteriocidal agents effect the … • Cell wall integrity • Cell wall synthesis • DNA synthesis and packaging Bacteriostatic agents inhibit … • Protein synthesis Modified from J. Goodson 1994

Antibiotics—Bacterial Sensitivity and Resistance

One of the greatest, world-wide medical problems of the next decades will certainly be bacterial resistance: Antibiotics that have up until now effectively eliminated sensitive bacterial species will no longer have any effect. The spectrum of activity of the well-known antibiotics will become ever smaller, and new antibiotics have not been developed for a very long time. The reason for the increase in bacterial resistance can be found in the careless and widespread use of antibiotics by physicians and in hospitals, but also in the almost grotesque use of antibiotics as growth enhancers in the food industry in certain countries; more than half of all antibiotic production, world-wide, is dedicated to this arena. In addition to naturally occurring resistance, resistance of previously sensitive bacterial species can occur in several ways:

  • Transfer via plasmids (virulence transfer, p. 35)

  • Point mutations

  • Selection via genetic “survival of the fittest”

The latter frequently occurs due to the overuse of antibiotic agents: If the dosage is too low or massively high (only the most pathogenic microbes survive), or if the antibiotic regimen is too short or too long.

662 Bacterial Culture—Sensitive Species In the sensitivity test depicted, the microorganisms were sensitive to all of the test substances (six antibiotics); the antibiotics would be effective. Note: Both antibiotics (upper left and upper middle) exhibit synergism; their inhibitory effects are mutually supportive. Right: Synergistic antibiotics, e.g., Augmentin (above) and metronidazole (below); the so-called “Winkelhoff cocktail.”
663 Bacterial Culture—Resistance Against Two Antibiotics It is becoming more and more often the case, especially in hospitals, that numerous bacteria are resistant to antibiotics (antibiotic pellets without any inhibitory effects; above, left and right). There exist varying resistance parameters in the population and in hospitals; see below! Figs. 662 and 663: Courtesy of A. Mombelli
664 Bacteriologic “Rogue’s Gallery” The ten most feared bacterial species, resistant to almost all antibiotics, and their most frequent “location.” P Population H Hospitals, institutions U Ubiquitous Periodontologically relevant species are, fortunately, not (yet) found in this list. Modified from S. Levy 1998
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Jul 2, 2020 | Posted by in Dental Hygiene | Comments Off on Medications
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