LOGIN
 
Share Page:
Back

Volume 36 , Issue 4
July/August 2021

Pages 723729


Torque Maintenance of Screw-Retained Implant-Supported Anterior Fixed Dental Prosthesis with Different Abutment Angulations After Aging

Walid Al-Zordk, MD, PhD/Tawfik Al-Dobaisi, MD/Mohamed Ghazy, MD, PhD


PMID: 34411211
DOI: 10.11607/jomi.8647

Purpose: To assess the impact of abutment angulation on loosening torque, torque loss, and percentage of torque loss in the prosthesis and abutment screws after aging of the implant-supported prosthesis. Materials and Methods: Fifty epoxy maxillary casts with missing central, lateral, and canine teeth were used, and each cast received two implants. All casts were divided into five groups (n = 10): (1) both implants received straight abutments (0-0); (2) the central implant received a straight abutment and the canine implant received a 17.5-degree angled abutment (0-17.5); (3) the central implant received a straight abutment and the canine implant received a 35-degree angled abutment (0-35); (4) both implants received 17.5-degree angled abutments (17.5-17.5); and (5) both implants received 35-degree angled abutments (35-35). For each cast, a three-unit zirconia restoration was fabricated, and a torque meter was utilized to tighten the abutment screw (25 Ncm) and prosthesis screw (18 Ncm). The reverse torque value was recorded for each screw. All restorations were subjected to 3,500 thermal cycles between 5C and 55C and load cycled for 150,000 cycles with 50-N load. After the loosening torque was measured for each screw, the torque loss and percentage of torque loss were calculated. Results: There was a statistically significant difference in the torque loss of the central prosthesis screw (P < .001) and canine prosthesis screw (P < .001) between study groups. The 35-35 group showed the highest percentage of torque loss, while the 00 group showed the lowest value. A significant difference was found regarding the torque loss of the central abutment screw (P < .001) and canine abutment screw (P < .001). The abutment screws of the 35-35 group showed the highest percentage of torque loss, while the 0-0 groups showed the lowest percentage of torque loss. Conclusion: Screw loosening of the prosthesis and abutment screws increases with increasing abutment angulation after aging. In the same fixed prosthesis, the torque loss in the prosthesis and abutment screws was higher in canine screws employing different angled abutments.


Full Text PDF File | Order Article

 

 
Get Adobe Reader
Adobe Acrobat Reader is required to view PDF files. This is a free program available from the Adobe web site.
Follow the download directions on the Adobe web site to get your copy of Adobe Acrobat Reader.

 

© 2022 Quintessence Publishing Co, Inc JOMI Home
Current Issue
Ahead of Print
Archive
Author Guidelines
About
Accepted Manuscripts
Submission Form
Submit
Reprints
Permission
Advertising
Quintessence Home
Terms of Use
Privacy Policy
About Us
Contact Us
Help