CORRECTION OF BIOCHEMICAL MARKER ALTERATIONS IN RAT GINGIVAL HOMOGENATES INDUCED BY EXPERIMENTAL FLUOROSIS AND ORTHODONTIC INTERVENTION WITH A THERAPEUTIC-PROPHYLACTIC COMPLEX

Abstract

Chronic fluoride intoxication and the mechanical stress associated with orthodontic tooth movement disturb periodontal homeostasis, provoking dysbiosis and attenuation of innate defence factors. The search for therapeutic-prophylactic complexes (TPCs) capable of correcting these changes remains a pressing issue. Aim of the study. To assess the impact of a newly formulated TPC on microbial colonisation indices (urease activity) and nonspecific antimicrobial defence (lysozyme activity) in rat gingival homogenates under conditions of experimental fluorosis and orthodontic intervention. Materials and methods. Forty male Wistar rats (4 months old, 280 ± 14 g) were assigned to four groups (n = 10 each): (1) intact control; (2) fluorosis (60 days of NaF in drinking water, 10 mg F⁻/kg); (3) fluorosis + orthodontic tooth movement (OTM); and (4) fluorosis + OTM + TPC. Orthodontic loading was simulated by fixing a spring between the upper molars for 30 days. In group 4 the TPC was administered orally during the final 30 days. After 60 days, urease and lysozyme activities were determined in gingival homogenates; the dysbiosis index (DI) was calculated as the urease-to-lysozyme activity ratio. Statistical analysis was performed in STATISTICA 6.1 using Student’s t-test; p < 0.01 was considered significant. Results. In group 2, urease activity increased three-fold, lysozyme activity decreased 1.6-fold, and DI rose 4.8-fold versus intact controls. Addition of OTM (group 3) further elevated urease activity 3.6-fold, reduced lysozyme 2.2-fold, and augmented DI 7.6-fold relative to controls. Administration of the TPC (group 4) significantly lowered urease activity 2.4-fold, elevated lysozyme twofold, and reduced DI 4.9-fold compared with group 3, approaching intact values. Conclusions. The experimental TPC effectively normalised biochemical markers of microbial colonisation and innate defence in gingival tissues under combined fluoride exposure and orthodontic loading, reducing dysbiosis to near-control levels.