Nilo Guliberto Martins Chavarry1, Daniel Perrone2, Maria Lucia Fleiuss Farias3, Bernardo Camargo Dos Santos4, Andrea Castro Domingos5, Alberto Schanaider6, Eduardo Jorge Feres-Filho7. 1. Division of Graduate Periodontics, School of Dentistry, Federal University of Rio de Janeiro, RJ CEP 21941-971, Brazil. 2. Laboratory of Nutritional Biochemistry and Food, Chemistry Institute, Federal University of Rio de Janeiro, RJ CEP 21941-909, Brazil. 3. Division of Endocrinology, School of Medicine, Federal University of Rio de Janeiro, RJ CEP 21941-913, Brazil. 4. Department of Nuclear Engineering (COPPE), School of Engineering, Federal University of Rio de Janeiro, RJ CEP 21941-972, Brazil. 5. Department of Oral Pathology, Oral Radiology and Oral Diagnosis, School of Dentistry, Federal University of Rio de Janeiro, RJ CEP 21941-971, Brazil. 6. Department of Surgery, School of Medicine, Federal University of Rio de Janeiro, RJ CEP 21941-913, Brazil. 7. Division of Graduate Periodontics, School of Dentistry, Federal University of Rio de Janeiro, RJ CEP 21941-971, Brazil. Electronic address: eduardoferes@odonto.ufrj.br.
Abstract
BACKGROUND: It has been shown that the oral aminobisphosphonate sodium alendronate (ALN) therapy reduces the risk of main fractures in osteoporotic women, but its effect on the jaw bones is poorly known. Here, we hypothesized that ALN affects the newly formed alveolar bone, particularly the quality of the type I collagen cross-linking. METHODS: Osteoporosis was induced by ovariectomy (OVX) in 6-month old rabbits. Six weeks following surgery, eight animals were treated by oral gavage with ALN (OVX + ALN) and ten received placebo (OVX + Pbo). Another six rabbits which were sham operated also received placebo (SHAM + Pbo). One month following the beginning of treatment, the upper and lower left first premolars were removed. Six weeks later, the upper and the lower right first premolars were also extracted. One month after the second extraction, biopsies were collected from the maxillary extraction sites and collagen crosslinks were analyzed in the newly formed bone tissue by HPLC. Also, at this time, mandibular bone segments were subjected to μCT. RESULTS: Animals treated with ALN achieved a roughly 2-time greater bone volume fraction value at a late healing period than animals in the other groups (p < 0.05). Collagen mean results were 2- to 4-times superior in the OVX + ALN group than in the control groups (p < 0.05). ALN-treated animals presented higher amounts of the non-enzymatic collagen cross-link pentosidine (PEN) than the sham-operated rabbits (p < 0.05), whereas the OVX + Pbo group presented the highest amount of PEN (p < 0.05). CONCLUSION: Alendronate increases bone volume and collagen accumulation, but does not fully rescue the non-osteoporotic alveolar tissue quality as is evident from the increased quantity of pentosidine.
BACKGROUND: It has been shown that the oral aminobisphosphonate sodium alendronate (ALN) therapy reduces the risk of main fractures in osteoporoticwomen, but its effect on the jaw bones is poorly known. Here, we hypothesized that ALN affects the newly formed alveolar bone, particularly the quality of the type I collagen cross-linking. METHODS: Osteoporosis was induced by ovariectomy (OVX) in 6-month old rabbits. Six weeks following surgery, eight animals were treated by oral gavage with ALN (OVX + ALN) and ten received placebo (OVX + Pbo). Another six rabbits which were sham operated also received placebo (SHAM + Pbo). One month following the beginning of treatment, the upper and lower left first premolars were removed. Six weeks later, the upper and the lower right first premolars were also extracted. One month after the second extraction, biopsies were collected from the maxillary extraction sites and collagen crosslinks were analyzed in the newly formed bone tissue by HPLC. Also, at this time, mandibular bone segments were subjected to μCT. RESULTS: Animals treated with ALN achieved a roughly 2-time greater bone volume fraction value at a late healing period than animals in the other groups (p < 0.05). Collagen mean results were 2- to 4-times superior in the OVX + ALN group than in the control groups (p < 0.05). ALN-treated animals presented higher amounts of the non-enzymatic collagen cross-link pentosidine (PEN) than the sham-operated rabbits (p < 0.05), whereas the OVX + Pbo group presented the highest amount of PEN (p < 0.05). CONCLUSION:Alendronate increases bone volume and collagen accumulation, but does not fully rescue the non-osteoporotic alveolar tissue quality as is evident from the increased quantity of pentosidine.