Date of Graduation


Document Type


Degree Type



School of Dentistry



Committee Chair

Matthew S Bryington

Committee Co-Chair

Harold Reed

Committee Member

Mark Richards


For an implant to be successfully loaded at the time of placement it must have a certain degree of initial stability. While many factors have been shown to influence primary stability, this study aims to examine the effect of positional change on implant stability. 18 Straumann dental implants (16 Standard plus SLA active 3.3mm RN implants, 1 Standard plus SLA 3.3 mm RN implant, and 1 SLActive 4.1 mm RC bone level implant) were placed into two bovine ribs. Implants were divided into two groups with nine in each group and were either backed out or advanced. The primary stability was assessed using an Osstell Mentor device following each quarter turn, until a full turn had been completed. Data was recorded and analyzed using linear regression and ANOVA. Results showed that after half a turn in either direction a significant change in primary stability was seen. Minor changes in implant position with conical implants did not seem to greatly influence initial implant stability. However, reversing a dental implant, even a quarter turn, will result in a measurable decrease in primary stability and caution should be used if immediate loading is to be considered.