The effect of screw torque maintenance and re-applying screw torque on the retention of prosthetic screw for multi-unit implant restorations
| dc.contributor.author | Handa, Karan | |
| dc.contributor.examiningcommittee | Solomon, Charlene (Restorative Dentistry) | |
| dc.contributor.examiningcommittee | Todescan, Reynaldo (Dental Diagnostics and Surgical Sciences) | |
| dc.contributor.supervisor | Pesun, Igor | |
| dc.date.accessioned | 2023-07-21T20:42:51Z | |
| dc.date.available | 2023-07-21T20:42:51Z | |
| dc.date.issued | 2023-07-18 | |
| dc.date.submitted | 2023-07-18T06:03:28Z | en_US |
| dc.degree.discipline | Restorative Dentistry (Prosthodontics) | en_US |
| dc.degree.level | Master of Science (M.Sc.) | |
| dc.description.abstract | Purpose: To investigate and compare different multi unit abutment prosthetic screw tightening protocols in terms of reverse torque values (RTV). Additionally, the effect of torquing and retorquing the same screw on RTV is also investigated. Methods: Nine implants (Nobel Replace Select, Nobel Biocare) with straight multiunit abutments and overlying temporary abutments help in place with prosthetic screw were placed in cold-cure acrylic (ProBase Cold, Ivoclar). Nine screw tightening protocols were tested: 1) torque to 15Ncm, 2) hold torque for 10 seconds, 3) hold torque for 20 seconds, 4) retorque at 2 minutes, 5) retorque at 10 minutes, 6) hold torque for 10 seconds and retorque at 2 minutes, 7) hold torque for 10 seconds and retorque at 10 minutes, 8) hold torque for 20 seconds and retorque at 2 minutes, 9) hold torque for 20 seconds and retorque at 10 minutes. Peak RTVs were measured after 30 minutes using a torque meter (MTT03-05, Mark-10). Each prosthetic screw was changed after each insertion with 10 total screws used per multiunit abutment. After determining the protocol with the highest average RTV, the specific protocol was used to evaluate if repeated cycles of insertion and removal on a single screw would have an impact on the reverse torque values. A single screw was torqued with the specified protocol and de-torqued after 30 minutes with the RTV measured. This was conducted another nine times over for a total of 10 cycles. Results: Protocol 5 (retightening after 10 minutes) had the highest average reverse torque value of 12.83 ± 0.16 Ncm and the Protocol 1 (control) had the lowest at 10.64 ± 0.18 Ncm with statistically significant difference. Conclusion: Different Implant screw tightening protocols can influence the reverse torque values. Multiple insertions of an implant screw may increase the reverse torque value. | |
| dc.description.note | October 2023 | |
| dc.identifier.uri | http://hdl.handle.net/1993/37425 | |
| dc.language.iso | eng | |
| dc.rights | open access | en_US |
| dc.subject | Full arch restorations | |
| dc.subject | multiunit restorations | |
| dc.subject | Reverse torque | |
| dc.subject | Preload | |
| dc.subject | Dental Implants | |
| dc.title | The effect of screw torque maintenance and re-applying screw torque on the retention of prosthetic screw for multi-unit implant restorations | |
| dc.type | master thesis | en_US |
| local.subject.manitoba | no | |
| project.funder.name | Dr. Gerald Niznick College of Dentistry Endowment Fund |