Different orthodontic appliances can cause periodontal inflammation. Fixed retainers, most commonly used orthodontic appliance to stabilize dental elements after orthodontic treatment can influence on the periodontal health, too. The main aim of this study was to make assessment periodontal tissue health status on lower incisors of patients with fixed mandibular retainers using objective periodontal indexes. Total numbers of 60 subjects, 30 male and 30 female patients with fixed mandibular retainers were included in this study. Before placing the retainer, an oral hygiene session and adequate periodontal treatment (if there was need) were performed on all patients. All the subjects were investigated after 3, 6 and 12 months. Plaque index by Silness & Loe; Gingival index (GI) by Loe & Silness, probing depth, clinical loss of attachment and the presence of gingival recession were assessed on the six inferior frontal teeth. Results showed that the mean score for the Plaque Index (PI), after three months was 1.04, after six months was 1.28 and after 12 months was
1.55. The mean Gingival Index (GI) after 12 months was 1.74 and after three months was 1.12. Periodontal sockets and presence of gingival recession were found in just one patient (1.66 % form all subjects) in all three examined periods. In our study was found a statistically significant difference for the Plaque Indexes (P> 0.05) in both groups, with higher scores among subjects having retainers for 12 months. These results are similar to those for the gingival index. From the results obtained in this study, it can be concluded that for a period from 3, 6 to 12 months, even there are effects of the orthodontic retainers on the periodontal health, they are minimal
