Effects of vitamin K2 administration on guided bone regeneration in diabetic rats.

Abstract

The present study aimed to investigate the histomorphometric and immunohistochemical impacts of vitamin K2 on guided bone regeneration (GBR) in calvarial critical-size defects (CSDs) in diabetic rats. A total of 30 rats were used in this study, comprising 12 non-diabetic (control) rats and 18 with streptozotocin-nicotinamide-induced experimental Diabetes mellitus (DM). In all rats, two calvarial CSDs were created: one defect was left empty (E), the other was treated with bovine-derived bone graft and collagen-based resorbable membrane (GM). Study groups were as follows: control rats administered saline (n = 6, C-E and C-GM groups) or vitamin K2 (n = 6, CK-E and CK-GM groups) and diabetic rats administered saline (n = 6, DM-E and DM-GM groups) or vitamin K2 (n = 6, DMK-E and DMK-GM groups). After 4 weeks of saline or vitamin K2 administration, the rats were euthanized. Bone defect healing and new bone formation were assessed histomorphometrically, and osteocalcin and osteopontin levels were examined immunohistochemically. Percentage of new bone formation was greater in CK-GM vs. CK-E and in DMK-GM vs. DMK-E [d = 3.86 (95% CI = 16.38-28.61), d = 1.86, (95% CI = 10.74-38.58), respectively, p < .05]. Bone defect healing scores were higher in CK-GM vs. CK-E and in DMK-GM vs. DMK-E [d = 2.69 (95% CI = -2.12 to -0.87), d = 3.28 (95% CI = 0.98-1.91), respectively, p < .05]. Osteocalcin expression levels were elevated in CK-GM vs. CK-E, in DMK-GM vs. DMK-E [d = 1.19 (95% CI = 0.08-1.41), d = 1.10 (95% CI = 0.02-1.22), respectively p < .05]. Vitamin K2 enhanced osteocalcin expression levels in DMK-E vs. DM-E [d = 2.78, (95% CI = 0.56-1.53), p < .05] and in DMK-GM vs. DM-GM [d = 2.43, (95% CI = 0.65-2.10), p < .05]. Osteopontin expression was enhanced in defects treated with GM vs. E defects [C-GM vs. C-E, d = 1.56 (95% CI = 0.38-2.01); CK-GM vs. CK-E, d = 1.91 (95% CI = 0.49-1.72); DM-GM vs. DM-E, d = 2.34 (95% CI = -1.12 to -0.50); DMK-GM vs. DMK-E, d = 2.00 (95% CI = 0.58-1.91), p < .05]. The research findings suggest that administering vitamin K2 in GBR for rats with DM favorably impacts bone healing in CSDs, presenting an adjunctive strategy for bone regeneration.