title: Topical metronidazole application as an adjunct to scaling and root planing.
abstract: OBJECTIVE
  This study was carried out to investigate the effect of 2 applications of a metronidazole 25% dental gel as adjunctive therapy to subgingival scaling with root planing.
  
  
  METHODS
  59 of the original collective of 64 patients with adult periodontitis were observed for a 9-month period. This randomised single-blind study was carried out in split-mouth design. Each patient had to have at least 2 pockets with a probing depth of > or =5 mm in each quadrant. The clinical parameters, pocket probing depth (PPD), attachment level (AL) and bleeding on probing (BOP), were recorded at all teeth on days 0, 91, 175 and 259; in addition, subgingival plaque samples taken from 45 patients were analysed by means of dark-field microscopy. Therapy comprised subgingival scaling and root planing (SRP) of all quadrants and additional application of metronidazole 25%, dental gel in 2 randomly selected quadrants (SRP+Metro). Treatment was confined to teeth with a baseline PPD of > or =5 mm. Average PPD and AL and the incidence of BOP were computed for all pockets with a baseline PPD of > or =5 mm, and the 2 methods compared. The main efficacy variable for evaluation of the 2 treatments was the difference in PPD on day 259.
  
  
  RESULTS
  Comparison of the 2 treatments revealed a statistically significant improvement in the clinical parameters for both treatment methods over the study period. Between baseline and day 259, significant differences in PPD (SRP+Metro: from 6.00 to 4.63 mm, SRP: from 6.02 to 4.83 mm) and BOP (SRP+Metro: from 67 to 31%, SRP: from 64 to 36%) were observed between the 2 treatment groups. Evaluation according to different patient groups demonstrated significant advantages of the combined therapy in previously-untreated patients, especially in female probands. Dark-field microscopy revealed a shift in the bacterial flora towards "healthy conditions".
  
  
  CONCLUSIONS
  The results show that only minor advantages are to be gained from the application of a metronidazole 25% dental gel as adjunctive therapy to subgingival scaling. The distinctly better results of combined therapy in previously-untreated patients calls for more thorough investigation.
authors.affiliation: Department of Periodontology, Dental School, Philipps University, Marburg, Germany. stelzelm@mailer.uni-marburg.de
authors.forename: M
authors.initials: M
authors.lastname: Stelzel
authors.forename: L
authors.initials: L
authors.lastname: Florès-de-Jacoby
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000368:Aged; D000890:Anti-Infective Agents / Q000008:administration & dosage*; D003131:Combined Modality Therapy; D012534:Dental Scaling; D005260:Female; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000008:administration & dosage*; D008875:Middle Aged; D010514:Periodontal Pocket / Q000628:therapy; D016745:Root Planing; D016037:Single-Blind Method
chemical_list: D000890:Anti-Infective Agents; D008795:Metronidazole