Wool-derived keratin hydrogel enhances implant osseointegration in cancellous bone

Aim: This study investigated whether a keratin hydrogel derived from wool enhances ossointegration of dental implants, using a cancellous bone model in sheep. Method: Ten female sheep received one dental implant per hind leg in the distal femoral condyles. Test implants were coated with 1 mL of keratin hydrogel containing sulphonated keratin and hydroxyapatite; control implants remained uncoated; implants were not functionally loaded axially. Biomechanical stability was tested with resonance frequency analysis (RFA) at placement and euthanasia. Animals were sacrificed after 4 weeks and resin-embedded histomorphometry performed. Findings: Bone appeared denser and more mature around the keratin-treated test implants. Average % bone-implant contact was significantly increased for the test (58.1 +/- 4.6 [SD]%) compared to control implants (34.4 +/- 7.5%) (p = 0.01). RFA values were lower for control (76.5 +/- 4.2 ISQ) than test implants (80.4 +/- 1.4) after 4 weeks (p = 0.04). Conclusion: the increase in osseointegration found in this model suggests that keratin hydrogel has the potential to enhance the successful osseointegration of dental implants placed into poor quality bone. (C) 2017 Wiley Periodicals, Inc.