• Soft Tissue and Bone Healing at Platform Shift Abutment in One-Stage Implants: A Radiographic, Histologic, and Histometric Study in Dogs

      Wenzel, Brent A.; Department of Oral Biology (2011-04)
      Matching-diameter and platform shift abutments were randomized to 40 dental implants placed into 5 dogs following mucoperiosteal flap elevation. 1x5 (width x height) mm peri-implant gap defects were surgically created in randomly assigned jaw quadrants. All implants were placed 2 mm subcrestally. Mucoperiosteal flaps were sutured around the abutments for primary intention healing. Radiographs were recorded immediately, 4-, and 8 weeks postsurgery when block biopsies were removed for histometric analysis. The histological examination showed the junctional epithelium was arrested coronal to the implant platform without significant differences among experimental conditions. Crestal bone height demonstrated no significant differences among groups at buccal or lingual sites. Bone-implant contact reached 0.4 mm below the platform at buccal sites. Higher variability was observed at lingual sites without differences among groups. Platform shift abutments offer negligible benefit compared to conventional abutments to maintain peri-implant crestal bone and soft tissue contours.