A lateral ridge augmentation study to evaluate a synthetic membrane for guided bone regeneration: an experiment in the canine mandible.

OBJECTIVES

To evaluate guided bone regeneration outcomes in defects protected with an in situ formed polyethylene glycol (PEG) hydrogel membrane as compared to a non-cross-linked collagen membrane (CM).

MATERIAL AND METHODS

Four mandibular alveolar ridge defects were created in eight hound dogs. Regenerative procedures were randomly allocated to one of four groups consisting of freeze-dried bone allograft, which is referred to in this study as freeze-dried bone xenograft (FDBX) + PEG, autogenous bone (AB) + PEG, AB + CM, and AB alone. After 8 weeks, titanium dental implants were placed into augmented sites. After 8 weeks of allowed time for osseointegration, the animals were sacrificed to harvest block specimens for bone-to-implant contact (BIC) and ridge width histomorphometric analysis.

RESULTS

Polyethylene glycol membranes had an exposure rate of 50% as compared to 12.5% for sites grafted with CM. Regenerative outcomes with respect to implant placement were least favorable for FDBX + PEG which had implants placed in 37.5% of augmented sites compared to 100% implant placement for all other groups. No statistically significant differences were noted between groups for ridge width measurements in implant and non-implant histologic sections (P > 0.05). Buccal BIC (%) values between treatment groups also failed to reach statistical significant difference (FDBX + PEG [60.2 ± 9.4]; AB + PEG [58.8 ± 8.5]; AB + CM [57.9 ± 12.8]; AB [61.0 ± 10.2]).

CONCLUSION

When used in conjunction with FDBX, PEG had unpredictable bone formation and in most cases negatively impacted future implant placement.