OBJECTIVE To assess if the screw design (self-drilling/self-tapping) and the pilot hole tapping could affect the insertion torque and screw pullout strength of the screw used in anterior fixation of the cervical spine. METHODS Forty self-tapping screws and 20 self-drilling screws were inserted into 10 models of artificial bone and 10 cervical vertebrae of sheep. The studied parameters were th...

STATEMENT OF PROBLEM Clinicians must know if a new screw can predictably increase reverse torque after multiple screw insertion cycles. PURPOSE The purpose of this study was (1) to compare the effect of multiple implant prosthetic screw insertion and removal cycles on reverse torque, (2) to determine whether a new screw, after multiple screw insertion cycles, affects reverse torque, and (3) t...

To evaluate torque loss a week after insertion, both in an in vivo and an in vitro experimental setup were designed. In the in vivo setup a total of 29 miniscrews were placed in 20 patients who underwent orthodontic treatment. Maximum insertion torque (MIT) was evaluated at insertion time (T1). A week later, insertion torque was measured again by applying a quarter turn (T2); no load was applie...

OBJECTIVE To evaluate the influence of pilot hole tapping on pullout resistance and insertion torque of pedicle screws with a conical core. METHODS Mechanical tests using a universal testing machine were performed on pedicle screws with a conical core that were inserted into pedicles in the fifth lumbar vertebra of calves. The insertion torque was measured using a torque meter with a capacity...

PURPOSE Implant stability at the time of surgery is crucial for the long-term success of dental implants. Primary stability is considered of paramount importance to achieve osseointegration. The purpose of the present study was to investigate the correlation between the insertion torque and primary stability of dental implants using artificial bone blocks with different bone densities and compo...

Purpose: The aims of the present study are to correlate the ISQ values, registered by the Osstell ISQ system, with the insertion torque during the placement of the implant, and to assess the influence of the thread initiator on the ISQ values and on the insertion torque. Materials and methods: 140 rough surface implants screw-shaped implants, placed in 10 bovine ribs, were assigned to Group A (...

PURPOSE To evaluate the difference between the dental surgeon's perception of implant stability and the actual insertion torque and actual values obtained through resonance frequency analysis (RFA) during implant insertion surgery. MATERIALS AND METHODS One hundred fifty-two patients who needed one or more dental implants were selected. A total of 514 Xive implants was inserted. For all 514 i...

PURPOSE The authors have observed a failure to achieve secure fixation in elderly patients when inserting a half-pin at the anteromedial surface of the tibia. The purpose of this study was to compare two methods for inserting a half-pin at tibia diaphysis in elderly patients. MATERIALS AND METHODS Twenty cadaveric tibias were divided into Group C or V. A half-pin was inserted into the tibias ...

PURPOSE To evaluate the insertion torque of a soft-tissue interference screw in relation to depth of insertion into the tibial tunnel when used for fixation of a quadrupled semitendinosus-gracilis autograft in anterior cruciate ligament reconstruction. TYPE OF STUDY Biomechanical cadaver study. METHODS Ten quadrupled semitendinosus-gracilis grafts were harvested from fresh-frozen cadaver kn...

BACKGROUND Primary stability is an important factor for the clinical success of orthodontic mini-screws. The present study made an attempt to evaluate the effect of insertion angle changes on the maximum insertion and removal torque of orthodontic mini-screws. MATERIALS AND METHODS In this experimental study, 72 mini-screws (Dual Top Anchor System, Jeil, 1.6 mm diameter, 8 mm length) were use...