IADR Abstract Archives
Zoledronic Acid Effect in Different Ages Mice Under Orthodontic Loading.
Objectives: Zoledronic acid (ZA), in both pediatric and adult, have been used worldwide. It promotes changes in bone remodeling that can influence orthodontic movement. The aim was to investigate the behavior of bone markers expression and histopathological features in different osteoporotic ages mice under ZA treatment, with or without orthodontic mechanical loading.
Methods: RUNX2, RANK, RANKL, OPG, SOST, MMP13 e SSP1 expression was evaluated by Real-time PCR at 12 hours and 12 days after 0.35N orthodontic force activation. Eighty young and adult mice (C57BL/6J) were distributed into two groups, that received one single dose of ZA, and two control groups received saline solution. Descriptive fluorescence and conventional microscopic analysis of HE-stained sections were done. ANOVA was performed by JMP (α=0.05).
Results: In the young mice ZA down-regulated RANK (p<0.0215), RANKL (p=0.0008), SOST (0.0039), RUNX2 (<0.0001) and SSP1 (p<0.0001). Remarkably, MMP13 (p=0.0352) showed up-regulation. Under orthodontic mechanical loading, up-regulation of mediators expressed by osteoblasts RANK (p=0.032), RANKL (p=0.0273), and by osteocytes SOST (0.026) and SSP1 (p=0.043) were observed. In adult mice, ZA down-regulated SSP1 (p=0.003) and MMP13 (p=0.042), outstanding up-regulated RANK (p=0.0004) and OPG (p=0.0003). Under loading ZA down-regulated RANKL (0.0012), MMP13 (p12h=0.0014; p12d=0.026) and SSP1 (p=0.0045). Microscopic analysis showed a delay in bone remodeling under orthodontic mechanical loading in experimental groups, also cementum resorption, alveolar crest and alveolar bone irregularity, lower count blood vessels and hyaline areas. More expressive alteration in adult mice.
Conclusions: Bone metabolism markers were modulated by zoledronic acid in a different way under orthodontic mechanical loading in young and adult mice. Only adult mice showed a downregulation in the osteoclastogenesis markers under transduction loading. Bone markers mediated by osteocytes were influenced by ZA only in young mice. Microscopic analysis showed in adult mice the most expressive alteration, which could cause many adverse effects in alveolar bone.
Methods: RUNX2, RANK, RANKL, OPG, SOST, MMP13 e SSP1 expression was evaluated by Real-time PCR at 12 hours and 12 days after 0.35N orthodontic force activation. Eighty young and adult mice (C57BL/6J) were distributed into two groups, that received one single dose of ZA, and two control groups received saline solution. Descriptive fluorescence and conventional microscopic analysis of HE-stained sections were done. ANOVA was performed by JMP (α=0.05).
Results: In the young mice ZA down-regulated RANK (p<0.0215), RANKL (p=0.0008), SOST (0.0039), RUNX2 (<0.0001) and SSP1 (p<0.0001). Remarkably, MMP13 (p=0.0352) showed up-regulation. Under orthodontic mechanical loading, up-regulation of mediators expressed by osteoblasts RANK (p=0.032), RANKL (p=0.0273), and by osteocytes SOST (0.026) and SSP1 (p=0.043) were observed. In adult mice, ZA down-regulated SSP1 (p=0.003) and MMP13 (p=0.042), outstanding up-regulated RANK (p=0.0004) and OPG (p=0.0003). Under loading ZA down-regulated RANKL (0.0012), MMP13 (p12h=0.0014; p12d=0.026) and SSP1 (p=0.0045). Microscopic analysis showed a delay in bone remodeling under orthodontic mechanical loading in experimental groups, also cementum resorption, alveolar crest and alveolar bone irregularity, lower count blood vessels and hyaline areas. More expressive alteration in adult mice.
Conclusions: Bone metabolism markers were modulated by zoledronic acid in a different way under orthodontic mechanical loading in young and adult mice. Only adult mice showed a downregulation in the osteoclastogenesis markers under transduction loading. Bone markers mediated by osteocytes were influenced by ZA only in young mice. Microscopic analysis showed in adult mice the most expressive alteration, which could cause many adverse effects in alveolar bone.