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Evaluation of Parathyroid Hormone Bound to a Synthetic Matrix for Guided Bone Regeneration Around Dental Implants: A Histomorphometric Study in Dogs
Author(s) -
Valderrama Pilar,
Jung Ronald E.,
Thoma Daniel S.,
Jones Archie A.,
Cochran David L.
Publication year - 2010
Publication title -
journal of periodontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.036
H-Index - 156
eISSN - 1943-3670
pISSN - 0022-3492
DOI - 10.1902/jop.2010.090562
Subject(s) - peg ratio , parathyroid hormone , polyethylene glycol , medicine , chemistry , dentistry , endocrinology , calcium , biochemistry , finance , economics
Background: A polyethylene glycol (PEG)‐based hydrogel matrix covalently bound to a 35‐amino acid peptide of parathyroid hormone cystein‐PTH 1‐34 (cys‐PTH 1‐34) was shown to enhance bone regeneration around implants. The aim of this study is to test if the addition of an integrin‐receptor–binding arginine‐glycine‐aspartic acid (RGD)–containing peptide at early healing time points improves the performance of the PEG matrix supplemented with cys‐PTH 1‐34 (PTH) when applied in acute defects around implants at early healing time points (2 and 4 weeks). Methods: Six dogs received 48 implants. Each side of the mandible was randomly assigned for implantation at day 0 or 2 weeks. A circumferential critical‐size defect was created at each site before implantation. Sites were randomly assigned to one of four groups: 1) PEG alone (PEG group), 2) PEG plus RGD (PEG/RGD group), 3) PEG plus PTH (PEG/PTH group), and 4) PEG plus RGD plus PTH (PEG/RGD/PTH group). Dogs were sacrificed 2 weeks after the second surgery, and specimens were obtained for histologic analysis. For the statistical analysis, mixed linear regression with repeated measurements was used, and a Dunnett‐Hsu adjustment was made for multiple comparisons. Results: At 2 weeks, the percentages of new bone formation within the defect were 12.43% for the PEG group, 15.95% for the PEG/RGD group, 15.32% for the PEG/PTH group, and 16.60% for the PEG/RGD/PTH group. At 4 weeks, the percentages of new bone formation within the defect were 30.01% for the PEG group, 27.90% for the PEG/RGD group, 29.89% for the PEG/PTH group, and 27.58% for the PEG/RGD/PTH group. A marginally significant difference (PEG/RGD/PTH group versus PEG group; P = 0.055) was found at 2 weeks but not at 4 weeks. The highest percentage of bone‐to‐implant contact (BIC) in the defect site at 2 weeks was observed for the PEG/RGD group (8.57%). The BIC after 4 weeks of healing ranged from 11.54% (PEG/RGD/PTH group) to 16.61% (PEG group). No statistically significant differences were observed in BIC. Conclusions : The effect of binding PTH covalently to a synthetic, RGD‐modified PEG hydrogel marginally significantly improved bone formation at 2 weeks of healing compared to the use of PEG alone. Bone regeneration within the defects increased in all groups at week 4 of healing without statistically significant differences.