The clinical and microbiological effects of Er:YAG laser and systemic metronidazole used as adjunctives to initial periodontal therapy in chronic periodontitis

The objective of this study was to compare the clinical and microbiological effects of Er:YAG laser and systemic metronidazole used as adjunctives to initial periodontal therapy in chronic periodontitis (CP) patients.A total of 27 CP patients ages ranging between 35-65, with a probing depth (PD) ? 5 and gingival index (GI) ? 2 in at least 3 single-rooted teeth within each quadrant were selected, divided into 3 groups randomly. Groups of patients recieved:; (1) Er:YAG laser combined with scaling and root planning (SRP)(SRP+Laser), (2) systemic metronidazole combined with SRP (SRP+Ant); (3) SRP. Subgingival plaque samples were obtained from selected teeth with PD ? 5 mm at day 0 and day 90. Following this procedure, clinical measurements including plaque index (PI), GI, PD, relative attachment level (RAL) were performed. For the microbiological evaluation total viable cell count (TVC) was performed and proportions of obligate and facultative anaerobic microorganisms were determined.At the end of the observation period, statistically significant improvements (p<0.001) in all clinical parameters were observed within each group. Intergroup comparisons of differences of PI values did not show statistically significance (p>0.05) however PI, PD (p<0.01) and RAL values (p<0.001) revealed statistically significant difference existed in favor of SRP+Laser group. Parallel to the clinical changes, all treatments reduced the number of total bacteria and proportions of obligately anaerobic microorganisms reduced at statistically significant levels at day 90 [SRP+Laser group (p<0.05), SRP+Ant group (p<0.001), and SRP group (p<0.05), respectively]. Proportions of facultative anaerobic microorganisms significantly increased at the end of the observation period within each group [SRP+Laser and SRP group (p<0.05), SRP+Ant group (p<0.001)]. Intergroup comparisons of microbiological parameters revealed no statistically significant difference (p>0.05).