Immediate loading of hydroxyapatite-coated implants in the maxillary premolar area: Three-year results of a pilot study

Statement of the problem. Although immediate loading of implants in the edentulous mandible has been described in the literature, there is limited information regarding immediate loading of single implants. Purpose. This prospective clinical study evaluated the clinical parameters of immediately loaded single-threaded hydroxyapatite-coated (HA) root form implants. Material and methods. Ten human subjects were included in this report. In all situations, a screw-retained provisional acrylic resin crown was placed in the maxillary premolar area immediately after implant surgery. Definitive screw-retained metal-ceramic prostheses were placed 6 months after surgery. Standardized periapical radiographs were made before implant surgery, immediately after surgery, and 1, 3, 6, 12, and 36 months after implant surgery. Mobility (measured with the Perio-Test), distance from implant platform to the gingival crevice, distance from the implant platform to the depth of the sulcus, peri-implant probing depth, and bleeding on probing index were recorded at 3, 6, 12, and 36 months after implant placement. For clinical measurements, a 5-mm healing abutment was placed. Results. All implants appeared clinically osseointegrated. Standardized radiographs demonstrated mean marginal bone loss of 0.6, 0.7, 0.8, 0.9, and 1.0 mm at 1, 3, 6, 12, and 36 months after implant surgery, respectively. Mean implant mobility was -3.3 at the day of surgery and -3.8, -3.4, -3.6, and -4.2 at 3, 6, 12, and 36 months, respectively. The distance from implant platform to the gingival crevice was 2.8, 2.4, 2.4, and 3.1 mm at 3, 6, 12, and 36 months, respectively. The distance from the implant platform to the depth of the sulcus was 0.8, 0.9, 0.9, and 1.1 mm at 3, 6, 12, and 36 months, respectively. The peri-implant probing depth was 3.6, 3.3, 3.2, and 4.3 mm at 3, 6, 12, and 36 months, respectively. The bleeding on probing index was 0.4, 0.4, 0.4, and 0.1 at 3, 6, 12, and 36 months, respectively. Conclusion. The results of this prospective pilot study provide initial evidence that single root form implants may be immediately loaded when placed at the maxillary premolar area.