Deposition of nanometer scaled calcium-phosphate crystals to implants with a dual acid-etched surface does not improve early tissue integration

Objective To evaluate hard and soft tissue healing to implants with a dual acid-etched surface with and without deposition of calcium-phosphate crystals. Materials and methods Three months after extraction of mandibular premolars in six Labrador dogs, four osteotomy preparations, 8 mm deep and 3 mm wide, were performed. The prepared canals were widened in the marginal 4 mm zone to 3.74 mm. Implants with an 8 mm long and 3.75 mm wide intraosseous portion and a 5.0 mm high and 4.0 mm wide transmucosal part were placed in such a way that the base of the wider neck-portion of the implant coincided with the crestal bone. The implants were dual acid etched (Osseotite (R); Biomet 3i). The surface of the test implants was, in addition, modified by a discrete deposition of calcium-phosphate crystals (Nanotite (TM); Biomet 3i). Every second implant placed was a test unit. After 2 weeks the implant installation procedure was repeated in the opposite side of the mandible. Two weeks later the animals were euthanized and biopsies were obtained and prepared for histological analysis. Results The degree of bone-to implant contact (BIC%) was larger at implants without (Osseotite) than in those with (Nanotite) calcium-phosphate crystals. No differences were found regarding soft tissue dimensions and composition between the two types of implants. Conclusion It is suggested that deposition of nanometer-sized calcium-phosphate crystals to implants with a dual acid-etched surface does not improve early tissue integration.