Research design

This in vivo study had a comparative, randomized, prospective research design, and each group consisted of 10 male beagle dogs that were veterinarian-controlled, healthy, and of similar weight. Animal Research Reporting in Vivo Experiment (ARRIVE) guidelines were used, and surgical procedure was approved by the Local Animal Experiments Ethical Committee of Erciyes University. Adequate measures were taken to minimize the pain or discomfort in the animals. A total of 36 dental implants (tissue level, 3.3 × 10 mm, Straumann AG, Basel, Switzerland) were inserted in the animals according to the non-submerged healing protocol. Figure 1 presents the flowchart of the research design employed in the study.

Sedation, anesthesia, animal care, and sacrifice

All the interventions were performed under general anesthesia. Enteral nutrition was stopped 12 h before the surgical procedure. General anesthesia was achieved with 2 mg/kg xylazine hydrochloride (i.m.) (Rompun, Bayer, Istanbul, Turkey) and 5 mg/kg ketamine hydrochloride (i.m.) (Alfamyne, Egevet, Izmir, Turkey). After the surgery, a 3-day antibiotic therapy with Streptomycin 0.5 g/day (I.E. Ulagay, Istanbul, Turkey) was administered in each dog. Postoperative care included daily observations regarding appetite and the documentation of adverse events such as bleeding, pain, swelling, and discomfort. At the end of the experiment, all the animals were sacrificed with a large dose of pentobarbital (i.v.). The animals in groups 3 and 4 were sacrificed at month 6 and the animals in groups 1 and 2 were sacrificed at month 8 after the extraction surgery.

Surgical procedure

The surgical procedure was commenced by the extraction of the mandibular second, third, fourth pre-molars, and the first molar bilaterally. The pupillary reflex was controlled after the administration of anesthetic drugs. Peri- and intra-oral tissues were disinfected with 10% povidone-iodine solution, and the surgical area was covered with sterile covering.