Vertical ridge augmentation has less long-term predictability than horizontal ridge augmentation due to common complications with vertical Guided Bone Regeneration (GBR), including early exposure of the barrier membrane and decreased bone stability. Objective: The purpose of this study was to evaluate the primary stability of short implants versus conventional implants, in vitro. Methods: Two groups of implants with reverse concave neck and neck micro threads (ULT, Ditron Dental, CA) were studied; short implants (Ø 6.0mm x 7mm) and conventional implant (Ø 3.75mm x 10mm). A total of 80 implants were placed by the same calibrated clinician at 800RPM, 40 short implants and 40 conventional implants. Each implant was placed in dense (type II) and soft (type IV) bone. Implant primary stability was recorded using insertion torque (IT), Resonance Frequency Analysis (RFA), and Periotest values. Statistical comparison with Analysis of Variance were completed to compare differences between groups. Results: The comparison of IT, RFA and Periotest of the two groups of implants showed statistical significance (P<0.0001) favoring the short implants (Ø 6.0mm x 7mm) in both the soft and dense bone qualities. Conclusion: Within the limitations of this study, short implants with wide diameter seem to have a higher level of implant stability compared to narrow implants with conventional length.