Short-term influence of lingual orthodontic therapy on microbial parameters and periodontal status. A preliminary study

Abstract

Objective: To perform a preliminary study of the short-term effect of fixed, customized lingual orthodontic appliances on periodontal and microbial parameters.

Materials and methods: The sample comprised 20 subjects (6 males and 14 females) with a mean age of 22.3 years +/- 8.6 years. Before (T(0)) and 4 weeks after placement (T(1)) of custom-made lingual appliances on the lower teeth only, plaque index (PI), probing pocket depth (PPD), and bleeding on probing (BOP) were measured. A 16S rRNA-based polymerase chain reaction (PCR) method was used to detect Aggregatibacter actinomycetemcomitans ( Aa ) and Porphyromonas gingivalis ( Pg ) in the crevicular fluid. To compare periodontal parameters on bonded lingual (testing) and unbonded palatal (control) and labial (control) sites between T(0) and T(1), the Wilcoxon test was applied.

Results: On the lingual aspects of bonded teeth, a significant increase of BOP (T(0): 23.4 +/- 22.5%; T(1): 46.2 +/- 23.5%; P = .001) and PI (T(0): 0.3 +/- 0.3; T(1): 1.0 +/- 0.7; P = .001) was observed, but no significant changes for PPD (T(0): 2.1 +/- 0.4 mm; T(1): 2.2 +/- 0.3 mm; P = .286) were found. On control sites, no significant changes were recorded for any periodontal parameter. Aa was found in 25% of the patients at baseline (5 subjects) and in 35% of the patients at T(1) (2 additional positive subjects), whereas Pg was found in 5% of the cohort at T(0) and at T(1) (same patient).

Conclusions: Even in the short term, insertion of fixed lingual appliances induced a worsening of periodontal parameters restricted to bonded lingual sites.