Single use Osstell SmartPegs for standard implants are made from a soft metal with a zinc-coated magnet mounted on top of it and attached to the implants or abutments’ internal threads. As the company does not provide SmartPegs for one-piece implants, we developed a customized SmartPeg for mini dental implants (3M™ESPE™ MDIs), which do not have internal threads (Fig. 1). After confirming that the standard SmartPegs™ are fabricated in aluminum, we customized a prototype in the same metal with a square-shaped assembly, which could be tightened with a small screw over the spherical top end of the MDIs. Our SmartPeg prototype was tested for reproducibility verifying the ISQ values on an MDI inserted into a wooden plank made of balsa wood. RFA measurements were taken 50 times, and a standard error of mean of all measurements was calculated.

Eight clinically healthy New Zealand white rabbits weighing >3.5 kg used for the study were housed in the Central Animal House facility. The head of the tibia/femur of the animals were chosen for the implantation of samples because they have been widely used as an animal model, and so, our results could be promptly compared [39–46]. The sample size of this study has been calculated based on the results of a similar study [36]. It was expected that 88% statistical power would be achieved by using sixteen 3M™ESPE™MDIs (experimental) and equal number of regular implants Ankylos®, Dentsply Friadent GmbH (control). Each animal received two implants on each of the hind limbs, i.e., the right and left tibia/femur heads, randomly. Therefore, each animal had a total of four implants, i.e., two experimental and two regular implants, randomly located.

The procedures were approved by the institutional animals’ ethics review board of McGill University, Montreal, Canada. Adequate measures were taken into consideration to minimize pain and distress in the animal during the procedure. Animals were anesthetized by intravenous injections of a ketamine hydrochloride-xylazine mixture at 35–50 and 1–3 mg/kg, respectively, according to the method described by Green et al. [47]. Acepromazine was injected subcutaneously at the dosage of 1 mg/kg. Further injections of the mixture were given to maintain anesthesia, if necessary. All surgical procedures were performed in accordance with McGill’s standardized operating protocol (SOP).