Therapy Advice

Carpegen® Perio Diagnostics results represent an important diagnostic factor for the clinical assessment of periodontal disease. Our therapy advice is based on the microbiological test result and follows recommendations of the German Society of Periodontology (DGP). Recommendations of other national professional societies may differ slightly from these; however, these differences do not significantly impact successful therapy. Initial treatment Initial treatment serves to establish hygienic conditions. Establishing and securing good oral hygiene by the patient at home helps control plaque because growth and vitality of plaque can be reduced Periodontitis Therapy 1. Conservative periodontitis therapy The goal of periodontitis therapy is to eliminate or drastically reduce the number of pathogenic bacteria. Mechanical treatment of infection (scaling and root planing) serves to remove all supra- and subgingival biofilm and calculus. In order to prevent already treated periodontal areas from reinvasion by pathogenic bacteria from regions that have not yet been treated, mechanical treatment of infection should be administered in all areas within 24 hours. In addition, patients obtain personalized instructions to maintain oral hygiene. 2. Adjuvant antibiotic therapy In cases of severe periodontal disease, adjuvant antibiotic therapy can improve the results of conservative periodontitis therapy3, 6-9, 17, 20.  Antibiotics should be prescribed that have been shown in clinical studies to be effective for this type of infection (table 1).

Pathogens present Antibiotic
Aggregatibacter actinomycetemcomitans (A.a.) and maybe others Metronidazole and amoxicillin
Porphyromonas gingivalis (P.g.), Tannerella forsythia (T.f.), Prevotella intermedia (P.i.) Metronidazole

Table 1: Choice of antibiotic for pathogens present, based on clinical studies 7, 9, 18, 20.

Antibiotics (recommendation of dosage see table 3) should be given immediately after the removal of supra- and subgingival biofilm and calculus and can be combined with short-term use of 0.2 % chlorohexidine mouth rinse.

 If there is intolerance to certain antibiotics, alternative antibiotics should be given. In the absence of sufficient clinical data, antibiotics should be chosen that, if given systemically, have been shown to reach concentrations in gingival fluid that are higher than the minimum inhibitory concentrations measured in vitro.

Pathogens present* A.a. T.f. P.g. P.i. F.n.
Amoxicillin + + ++    
Metronidazole   ++ + + ++
Ciprofloxacin +        
Doxycycline   +      
Clindamycin   ++      
Metronidazole and amoxicillin** + ++ ++ + ++
Metronidazole and ciprofloxacin** + ++ + + ++

+ = 10-fold MIC90
++ = 100-fold MIC90
** = derived from individual measurements

Table 2: Concentration of different antibiotics in gingival fluid after systemic use, shown as multiple of the minimum inhibitory concentration (MIC90; in vitro) against different periodontal pathogenic germs1, 4, 5, 10-16, 19.

* Carpegen® Perio Diagnostics identifies the pathogens Aggregatibacter actinomycetemcomitans (A.a.), Porphyromonas gingivalis (P.g.), Tannerella forsythia (T.f.), Treponema denticola (T.d.), Fusobacterium nucleatum (F.n.) and Prevotella intermedia (P.i.). Due to extremely difficult cultivation, no MIC values are known for Treponema denticola.

Antibiotic Dose (adults) Duration
Metronidazole 3 x 400 mg/day 7 days
Metronidazole and amoxicillin (combined) 3 x 400 mg/day
3 x 500 mg/day
7 days
7 days
Amoxicillin 3 x 500 mg/day 14 days
Metronidazole and ciprofloxacin (combined) 2 x 500 mg/day
2 x 250 mg/day
7 days
7 days
Ciprofloxacin 2 x 250 mg/day 10 days
Clindamycin 4 x 300 mg/day 7 days
Doxycycline 1 x 200 mg/day then
1 x 100 mg/day
1 day
18 days

Table 3: Dose recommendations for antibiotic therapy for adults2. For children, dosage needs to be adjusted according to body weight.


Four to six weeks after mechanical treatment of infection, a clinical periodontal diagnostic analysis should be repeated in order to assess the treatment success. Following antibiotic therapy, pathogens should be determined again as well in order to assess treatment success and as a prognostic tool to avoid relapse. Thus, insufficient reduction of pathogenic load can be detected early so action can be taken.

Maintenance therapy

For sustained long-term success, supportive periodontitis therapy is indispensable. Every 3 to 6 months (recall) newly accumulated supra- and subgingival biofilm and calculus should be removed. Patients should be re-motivated and re-instructed about adequate and effective oral hygiene on a regular basis. Therapy success should be monitored by periodontal and, when indicated, microbial analysis once a year. If the disease still progresses, additional antibiotic therapy might be indicated, following the determination of pathogens.


A list of literature about antibiotic therapy of periodontal disease is included in our information brochure for dentists (pdf version) which you can request from us at any time.