## Appendix A A Appendix  
### A Appendix  
Figure 6: CBCT scans show a hyperdense border along the implant bone walls at the end of the osteotomies procedures: Bone compactors (BC); osseedensification drills (OD). As suggested by other authors, good compaction of bone trabeculae in bone marrow may justify high ISQ values, especially in the crestal region [31; 42; 43]. Removal torque does not provide data on implant stability directly, but rather represents a parameter indicating the relationship between bone and implant surface, especially for in vitro and ex vivo studies [44]. In fact, removal torque testing is not a well-documented clinical stability parameter in the literature. In our study, both BC and OD protocols showed high PRT values. This report shows that surgical procedures involving bone changes allow a closer relationship between implant fixture and the surrounding bone, obtaining a better implant stability in the post-immediate implant placement [17]. This is a major requirement for protocols that involve immediate loading [45; 46; 47]. In particular, a statistically higher PRT value was found in the BC protocol compared with the value found in the OD technique. As stated by other authors, the use of Densah drills involves the plastic deformation of bone particles along the length of the osteotomy [3]; nevertheless, bone compaction performed by manual bone spreaders helps to create a similar effect of a gradual elastic deformation, preserving collagen integrity [3; 17]. These concepts translate into better redistribution of the material with less compressive force than mechanical protocols. Both BC and OD are bone preservation methods. They are vastly different to under-preparation standard drilling to create a misfit method. In our study, both groups of osteotomies were not undersized and were within 0.2 to 0.3 mm smaller than the implant major diameter. As recently assessed in a preclinical study implant site, under-preparation with standard extraction drilling to create a misfit would lead to osteodestruction and the stress/strain linked to the severe downsized osteotomy could affect BIC and implant stability [29]. In fact, the micro-fractures performed in the peri-implant bone can cause a huge zone of dying osteocytes [48]. High interfacial pressures and mechanical under-preparation seem to produce a pro-resorptive environment as indicated by the lack of alkaline phosphatase activity and collagen I. Several authors assessed that the osseodensification technique produces bone chips usable as autografts during implant site preparation [49]. This phenomenon could play a main role in the implant site healing thanks to the osteogenesis and osteoconductive properties of the autologous bone chips. The manual bone compaction procedure represents a less invasive method allowing maintenance of a greater amount of bone compared with standard drilling procedures, with a progressive compaction of the bone trabeculae carefully controlled by the clinician during the surgical phases [17]. The analysis of the values recorded in our study showed an excellent primary stability can be achieved performing both techniques. While the ISQ measurement did not reflect any significance value specially in any human clinical oral sites [50; 51], the high values recorded suggest a condition favourable to the osseointegration phenomenon. Moreover, the PIT values represent a more predictive parameter for the evaluation of the relationship between the implant surface and the surrounding bone during the implant placement, especially in clinical situations [52]. Furthermore, insertion torque and ISQ are assessed as independent and incomparable methods of measuring PS [53]. Primary implant stability could be underestimated, mostly in the presence of medium or low values of PIT and ISQ, showing insufficiency in preventing errors when an immediate loading technique is performed [54]. This study was designed to analyze two surgical protocols and the primary stability values obtained in cancellous bone.