Guided bone regeneration using beta-tricalcium phosphate with and without fibronectin-An experimental study in rats.

OBJECTIVE: This histomorphometric study compared bone regeneration potential of beta-tricalcium phosphate with fibronectin (ß-TCP-Fn) in critical-sized calvarial defects (CSDs) in rats to assess whether fibronectin (Fn) improved new bone formation. MATERIAL AND METHODS: Critical-sized calvarial defects were created in 30 adult male Sprague Dawley rats, which were divided into four groups according to the time of euthanasia (6 or 8 weeks of healing) and type of filling (ß-TCP-Fn/6 weeks, ß-TCP/6 weeks, ß-TCP-Fn/8 weeks and ß-TCP/8 weeks). The primary variables related to new bone formation were augmented area (AA) and gained tissue (GT; sum of mineralized bone matrix [MBM] and bone substitute [BS]). Secondary variables were the diameter of the defect, MBM, non-mineralized tissue (NMT) and BS. RESULTS: A total of 29 rats and 58 histological samples were evaluated, 28 (48.3%) samples obtained at 6 weeks and 30 (51.7%) at 8 weeks, homogeneously distributed between right and left sides. Thirteen (22.4%) were treated with ß-TCP-Fn, 16 (27.6%) with ß-TCP and 29 (50%) were controls. At 8 weeks, histomorphometric analysis showed significant differences in AA using ß-TCP and ß-TCP-Fn versus controls (p = 0.001 and p = 0.005, respectively). Bone turnover expressed as % within the target area was slightly higher but not statistically significant in the ß-TCP-Fn than in ß-TCP (MBM) at 6 weeks versus 8 weeks (p = 0.067 and p = 0.335, respectively). Finally, the total GT area in mm2 was higher using ß-TCP-Fn as compared to ß-TCP (p = 0.044). CONCLUSIONS: ß-TCP-Fn was slightly but non-significantly more effective than ß-TCP without Fn for improving the volume of regenerated bone in CSDs of rats, possibly allowing a more efficient bone remodelling process. This effect however should continue being investigated.

Bone Regeneration Using Adipose-Derived Stem Cells with Fibronectin in Dehiscence-Type Defects Associated with Dental Implants: An Experimental Study in a Dog Model.

PURPOSE: To determine the bone regeneration potential of a ceramic biomaterial coated with fibronectin and adipose-derived stem cells covered in three-wall critical-size defects associated with dental implants. MATERIALS AND METHODS: In a total of 18 dogs, four dehiscence-type and critical-size defects were created surgically in the edentulous alveolar ridge with the simultaneous placement of dental implants. Defects were randomly regenerated using biomaterials coated with particulate ß-tricalcium phosphate (ß-TCP), ß-TCP with fibronectin (Fn) (ß-TCP-Fn), and ß-TCP with a combination of Fn and autologous adipose-derived stem cells (ADSCs) (ß-TCP-Fn-ADSCs), leaving one defect as the control. The animals were divided into three groups according to the time of euthanasia (1, 2, or 3 months). RESULTS: Statistically significant differences between the three study groups (ß-TCP, ß-TCP-Fn, ß-TCP-Fn-ADSCs) and the control group in the total area of bone regeneration and mineralized and nonmineralized tissue at 1, 2, and 3 months of healing were not observed. At 2 months, defects treated with ß-TCP-Fn-ADSCs showed a significant decrease in the percentage of bone-to-implant contact (BIC) as compared with the ß-TCP-Fn (P = .041) and control (P = .012) groups. At 3 months of healing, however, significant differences in BIC between the three study groups and controls were not found (P = .388). CONCLUSION: The use of ADSCs in the bone regeneration processes of dehiscencetype defects associated with simultaneous implant insertion does not seem to improve the area of bone regeneration or the percentage of BIC compared with other biomaterials or the control alveolar defect.

Suplementación en vitamina C y rendimiento deportivo (I) / Vitamin C supplementation and sport performance (I)

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