Experimental study on penetration of dental implants into the maxillary sinus at different depths

Objective The purpose of this study was to investigate the effect of the dental implant penetration into the maxillary sinus cavity in different depths on implant and sinus health in a dog model. Materials and methods The study sample included eight titanium dental implant placed in four female dogs immediately after extraction of the first maxillary molar in the palatal socket and assigned into four groups according to the protruding of implant tips (control group A = 0 mm, and study groups B, C, and D with protrusion of 1, 2, and 3 mm, respectively). The bone blocks of the implants were harvested 5 months postoperatively and evaluated by cone beam computed tomography (CBCT) and histological analysis. Results The whole groups showed no signs of inflammation during the 5-month period of the study. The tips of the implants in group B with penetrating depths of 1 mm were found to be fully covered with newly formed bone. The tips of the implants in group C with penetrating depths of 2 mm were exposed in the sinus cavity and showed partially new bone coverage, while depths of 3 mm in group D were found to have no bone formation and the dental implant fixture sites were communicated with the sinus cavity. No significant differences were found among the groups regarding implant stability. Conclusion Despite the protrusion extents, penetration of dental implant into the maxillary sinus with membrane perforation does not compromise the sinus health and the implant in canine.