The effect of the design of the abutment screw on the loosening force
- Author:
Tae-Hun KIM
1
;
Young-Hun KWAK
;
Soo-Yeon LEE
;
Hee-Jung KIM
Author Information
- Publication Type:Original Article
- From: Oral Biology Research 2025;49(4):22-
- CountryRepublic of Korea
- Language:English
- Abstract: This study aimed to assess the stability of the screw joint by comparing the implant abutment screw with a Morse-tapered design in the head with the existing implant abutment screw with a butt joint design. After the implant was fastened with either a support screw with a Morse-tapered design or an abutment screw with a butt-joint design, the specimens were divided into six groups. The nonloaded specimens were assigned to two groups: Group 1 (Morse taper) and Group 2 (butt joint). The specimens subjected to 100,000 loading cycles were assigned to Groups 3 and 4. Those subjected to 500,000 loading cycles were assigned to Groups 5 and 6. Each abutment screw was tightened to 35 Ncm. For Groups 1 and 2, the removal torque was measured 1 hour after tightening. For the other four groups, prostheses were fabricated and connected, and a cyclic loading of 50 N was applied before measuring the removal torque.The mean removal torques for Groups 1–6 were 34.24±1.67, 27.30±0.74, 31.80±1.61, 27.20±0.93, 32.82±0.90, and 26.84±1.39 Ncm, respectively. Under all loading conditions, the abutment screws with the Morse-tapered design showed a higher mean removal torque than those with the butt-joint design. Implants assembled with abutment screws having a Morse-tapered connection design showed greater stability than those with a conventional butt-joint connection design.
