• Parkin Watin D.D.S.
• Naulchavee Hongprasong D.D.S., M.D.S., Diplomate, Thai Board of Periodontology
• Kitti Torrungruang D.D.S., Ph.D
• Jintakorn Kuvatanasuchati D.D.S., M.S.
• Garnpimol C. Ritthidej, Ph.D

Objectives To study the results of the local delivery of 2% local-made metronidazole gel as an adjunct
to scaling and root planing in the treatment of chronic periodontitis.

Materials and methods Twenty-six chronic periodontitis patients with 6-8 mm periodontal pockets
who had no systemic diseases and had not received any antimicrobial drugs or non-steroidal
anti-inflammatory drugs within the past 3 months were selected from the periodontal clinic, Faculty of
Dentistry, Chulalongkorn University. All patients were obtained the initial periodontal therapy by
scaling, root planing and oral hygiene instruction. The subjects were simple randomly assigned to a test
group (scaling and root planing with metronidazole gel) or a control group (scaling and root planing
with placebo). Three doses of metronidazole gel or placebo were applied every other day for each
patient. Clinical parameters including bleeding on probing, probing pocket depth, gingival recession
and clinical attachment level were measured on the deepest site before treatment and 3 and 6 months
after treatment using occlusal stents for the reference point of each tooth. The changes of clinical
parameters were compared by Mann-Whitney U-test, Chi-Square test and Wilcoxon Signed Ranks
test with confidence level at 95%.

Result There was statistically significant improvement in clinical parameters for both treatment methods
at 6th month after treatment. The mean reduction in probing pocket depth was 1.30 mm and the mean
clinical attachment gain was 1.10 mm in test group whereas those of control group were 0.56 mm and
0.50 mm, respectively. Significant differences between groups were found in reduction of probing
pocket depth at 6 months and in reduction of bleeding on probing at 3rd to 6th month period.

Conclusion These results suggested that the use of 2% metronidazole gel as an adjunct to scaling and
root planing could improve periodontal outcomes in chronic periodontitis patients, however, further
research and development of the local metronidazole gel is required.

(CU Dent J. 2009;32:133-42)