Thoughtful use of local delivery antimicrobial agents in periodontitis
|Thursdayrsday 3 December 2015 - 7:38 PM 2557 0|
Local delivery antimicrobial agents (LDAs) have long been readily available for treatment of periodontitis and more recently for peri-implantitis. LDAs were developed in response to challenges with refractory periodontitis cases and challenges using systemic antibiotics, namely achieving direct contact with the disease-causing bacteria. The rationale for the development of local delivery agents was to aid traditional periodontal therapies in overcoming bacterial pathogens directly at the site of clinical damage—the periodontal sulcus. Arguments for or against the use of LDAs are numerous, and the practitioner needs to develop a thoughtful decision tree regarding when to consider their use.
Periodontal disease is multifactorial in nature and needs to be treated as such. (1) Consideration must be made for treatment of the biofilm, root anatomy, host response, the patient’s general health, and acceptance of his or her role in the disease process. It is well accepted that initiation of treatment with SRP is an effective treatment modality for periodontitis patients. (2,3) When do we need to consider additional treatment modalities?
Comparison of treatment modalities
When SRP alone is compared with combined SRP and applications of LDAs, little difference is seen in clinical results. (2,3,4) Therefore, it makes little sense to use LDAs in initial treatment. What do we do for the patient with localized sites that do not respond to initial treatment? We must first be able to determine if the site is truly refractory, or nonresponsive, to traditional therapy, or if the therapy that was provided was poorly executed. Studies show that sites nonresponsive to SRP frequently benefit from a second round of SRP, (4) which is often the reason for the treatment to be recommended by a periodontist upon patient referral.
The challenges with SRP are complete removal of the biofilm, root anatomy, achieving a cleansable site, and limiting bacterial recolonization. It is because of these challenges that the benefits of LDAs may be realized. These benefits may include improved patient compliance, direct application to the site of active disease, and general avoidance of complications with systemic antibiotic use. In maintenance patients unable to proceed with surgical care and nonresponsive to traditional therapies, these may provide assistance as a useful adjunct. Combined therapy has been shown to have a greater probing depth reduction (1.81 mm vs. 1.08 mm) and gain of clinical attachment (1.08 mm vs. 0.56 mm) in these patients, but this has not been documented beyond six months. (5) These improvements can initially be clinically significant, but the benefits tend to be transient in nature. (6) However, in patients unable or unwilling to proceed with surgical treatment modalities, the transient benefits of using LDAs may offer some merit.
Challenges with use of LDAs
The challenges with this treatment include:
- Finding an antibiotic specific for multiple periodontal pathogens
- Application of the drug to the site of active disease
- Maintenance of effective antibacterial concentrations of antibiotics
- Obtaining long-term clinical improvements
LDAs are often chosen due to empirical evidence relevant to the clinical situation and not specific for the patient and bacteria involved. The LDAs do not inhibit all bacteria and do not eliminate biofilms. The fact is that LDAs are often placed in defects without effective scaling and root planing, home care, or maintenance.
LDAs are most often recommended for use by manufacturers for forms of acute periodontitis or peri-implantitis and refractory periodontitis. The clinician needs to be able to adequately diagnose when these changes arise, and this has a significant influence on expected outcomes with treatment.
The American Academy of Periodontology does not acknowledge refractory periodontitis as a separate disease entity. (7) Refractory periodontitis is defined as “destructive periodontal diseases in patients who, when longitudinally monitored, demonstrate additional attachment loss at one or more sites, despite well-executed therapeutic and patient efforts to stop the progression of disease.” (8) This definition excludes patients with inadequate conventional therapy, accompanying systemic conditions complicating treatment, or a return of progressive attachment loss after a period of successful maintenance care. (8)
In summary, LDAs are not a panacea for unstable periodontitis lesions/conditions. The ability of the clinician to “read” the tissues during maintenance visits using assessment of reprobing results, tissue form, firmness, and color, as well as probing assessment of root roughness/smoothness, is critical to the long-term successful maintenance of the periodontal patient. Changes in patient circumstances and behavior in regard to overall physical health, stress, alcohol or other drug consumption, use of tobacco products, etc., must be assessed on an individual basis to determine reasons for lack of stability and the need for additional intervention, possibly including the use of LDAs if other factors can be eliminated as possible causes. These products alone will not serve as long-term solutions to periodontal instability without proper assessment of individual patients.