Effects of systemic ornidazole, systemic and local compound ornidazole and pefloxacin mesylate on experimental periodontitis in rats

Abstract

Background: The purpose of the current study is to evaluate the effects of systemic ornidazole (SO) and systemic and local compound ornidazole and pefloxacin mesylate (SCOPM/LCOMP) on the inflammatory response associated with rat experimental chronic periodontitis (ECP) in sites with subgingival debridement.

Material/methods: Periodontitis was induced in male Sprague-Dawley rats by placing a thin steel ligature around the upper first molars and inoculating them with Porphyromonas gingivalis 381. After the successful induction of the rat ECP, the periodontitis rats were randomly divided into 3 different combined treatment groups: (A) SO with scaling and root planing (SRP); (B) SCOMP with SRP; and (C) LCOMP with SRP. After 2 weeks the effects of the treatments were evaluated based on gingivitis, plaque index, probing pocket depth, aspartate aminotransferase, alveolar bone loss, and hematoxylin-eosin staining of the region around the first molars.

Results: After treatment, comparison with ECP was performed. The mean percentage reductions of SBI in SO, SCOPM, and LCOPM were 27.73%, 33.61%, and 58.82%, respectively. Those of PI were 33.20%, 42.80%, and 60.00%; those of PPD were 48.66%, 55.70%, and 72.48%; those of GCF-AST were 41.64%, 49.03%, and 66.42%; and those of ABL were 41.19%, 43.63%, and 54.47%, respectively. The inflammatory score of H&E showed median scores of 2.5, 1.75, 1.63, and 0.95 for ECP, SO, SCOMP, and LCOMP, respectively. All 3 treatment groups exhibited significantly reduced inflammation indicators (P<0.05). Of the 3, group C was the most effective (P<0.05).

Conclusions: Although all the combined treatment groups responded to therapy with significant resolution of the infection, adjunctive LCOMP therapy is more effective for periodontitis.

Figure 1

Effects of the SRP+antibiotics on various parameters (live) in rats subjected to ECP. n=12. a: vs. NORMAL P<0.05, b: vs. SRP+SO P<0.05, c: vs. SRP+SCOMP P<0.05 (ANOVA & Paired t-test).

Figure 2

Macroscopic aspects of periodontia of rats submitted to ECP and the effects of SRP+antibiotics on ABL in rats subjected to ECP. The normal periodontia exhibited no resorption of the alveolar bone (A, original magnification ×50). In contrast, The periodontia from ECP rats demonstrated severe resorption of the alveolar bone with root exposure (B, original magnification ×50). The periodontia from ECP rats demonstrated severe resorption of the alveolar bone with root exposure (A, original magnification ×50). In contrast, normal periodontia exhibited no resorption of the alveolar bone (B, original magnification ×50). Compared with the normal group, a significant increase in the distance between cemento-enamel injunction and alveolar crest was observed in the ECP group (C). After treatment, the increase was significantly reduced (C). Among those treatment groups, SPR+LCOMP was most effective (C). n=8. a: vs. NORMAL P<0.05, b: vs. SRP+SO P<0.05, c: vs. SRP+SCOMP P<0.05 (ANOVA & Paired t-test).

Figure 3

HE staining of the rat periodontia subjected to ECP and treated with SRP+antibiotics. Photomicrographs (A and B) showing the region around the first molars of normal rats; these indicate that the gingival, periodontal ligament, and cementum are normal. Rat periodontia subjected to ECP (C and D) showed inflammatory cell infiltration with apical migration of the junctional epithelium, as well as severe cementum destruction. SRP +SO (E), SRP +SCOMP (F), and SRP +LCOMP (G) all resulted in a significant reduction in the number of inflammatory cell infiltration and cementum destruction. Among those, SPR+LCOMP was most effective (HE stain; original magnification A, C ×400 B, D, E, F, G ×100). According to the evaluation standard, the scores ranged from a scale of 0 to 3. Data are medians with the range within the parentheses (H); n=4. a: vs. NORMAL P<0.05, b: vs. SRP+SO P<0.05, c: vs. SRP+SCOMP P<0.05 (Kruskal-Wallis and Dunn’ tests).