Study of the Differences in a Percussion-type Implant Stability Measuring Instrument according to Bridge prosthesis and screw loosening

Abstract

This study aimed to investigate the effect of different conditions on the implant stability test (IST) value of three-unit implant bridges. Fifteen pairs of specimens were prepared. Two internal conical-type implants were placed in artificial bone using a torque of 35 to 45 Ncm. Three-unit monolithic zirconia bridges (Perfit ZR) were fabricated using CAD-CAM. Im-plant Stability Quotient (ISQ) values were measured for each implant. IST value was measured under different conditions: healing abutment, without cementation, with cementation, one prosthesis unscrewed, and two prostheses unscrewed. The results showed statistically significant differences according to the conditions (p <0.05). The lowest IST level was observed in the groups tested on healing abutment and the prosthesis without cementation. The highest IST level was observed in the groups with cemented prostheses. There was no significant difference according to screw loosening. IST values for all groups measured above 79, indicating high stability with consistent tendency. The present study implied that IST values could be used as a reference restrictedly for assessing implant stability and conditions on bridge-type prostheses.