Effect of single-dose locally applied lactoferrin on autograft healing in peri-implant bone in rat models

Immediate dental implant installation into fresh extraction sockets has become a common surgical technique and yields successful clinical results. In addition, complete contact may not be possible with this procedure cause of defects between the bone wall and the implant surface. Therefore, different graft materials have been used in the literature to increase the peri‑implant bone volume. The aim of the present study was to evaluate the effect of single-dose and locally applied lactoferrin on autograft healing in peri‑implant area and bone implant contact value. Twenty-four Sprague-Dawley rats were included in this study. Firstly, a trephine drill was used for creating a cylindrical bony defects (6.5 mm in diameter and 3 mm in depth) under sterile saline irrigation in the lateral side of the femur. Subsequently, implant beds -2.5 mm diameter and 6 mm depth - were prepared in the middle of each defect with special implant drills. All of the implants were installed and primary stability was achieved. Rats were randomly divided into 3 groups (n = 8 each): Group-1 had empty defects, Group-2 had defects filled with autograft, and Group-3 had defects filled with autograft and lactoferrin solution (100 μg/ml) combination. All of the rats were sacrificed at postoperative 4th week and samples were analyzed with micro-computed tomography, histomorphometry and immunohistochemistry respectively. It was found that Group 3 had the least area of fibrous tissue (6.75±0.83mm²) according to the other 2 groups (p<0.001). On the other hand, Group 3 had the highest osteoblast number (25.50±3.29), osteoclast number (21.25±1.03), newly formed bone area (20.50±1.30 mm²), total healing area (22.62±0.93 mm²), defect closure rate (80.37±1.40%), bone implant contact value (23.2%±0.6%), and percentage bone volume (18.2%±0.3%) (p<0.001). Matrix metalloproteinase-3 expression was found to be highest in Group 3 by immunohistochemistry analysis. In this study it was observed that the results of the different analysis techniques supported each other. According to these findings it can be stated that a single-dose and locally applied lactoferrin solution plays an important role in the autograft healing in peri‑implant area and increasing bone implant contact value. These findings will shed light on further clinical studies of implant osseointegration.