Date of Graduation

2018

Document Type

Thesis

Degree Type

MS

College

School of Dentistry

Department

Orthodontics

Committee Chair

Matthew S Bryington

Committee Co-Chair

Bryan D Dye

Committee Member

Bryan Weaver

Abstract

Objectives: To determine the accuracy of placing implants using a digital workflow. Variables were compared to see if there was an effect on implant position accuracy. These included bone level (BL) versus bone level tapered (BLT) implants, positioning of implants adjacent to tooth support versus further across an edentulous ridge, and impact of the surgical guide requiring adjustment to fully seat. Furthermore, two methods of post-operative assessment were compared to evaluate consistency of each approach.;Methods: A typical work up for digital implant planning was performed on a sectioned pig jaw. The DICOM CBCT file and IOS STL file were imported into coDiagnostiX to virtually plan implant placement (Dentalwings, Montreal, Canada). Two implants were planned for each of ten specimens, with one positioned adjacent to the Surgical guide tooth support (Implant A) and a second positioned more distally along the edentulous ridge (Implant B). The guide was designed and 3-D printed with 5 mm sleeves to allow full preparation of the osteotomy. The sites were prepared following Straumann guided surgery protocols, with the exception of utilizing irrigation. The implant was free-handed into position, until full depth of placement was achieved. The jaws were then post-operatively assessed using two methods: a post-operative CBCT scan and an intraoral scan of implant scan bodies. Each set of files were overlapped with the treatment evaluation tool of the coDiagnostiX software, to compare the planned to the resulting implant position.;Results: The average error was more pronounced at both the base and tip of implants in the mesial direction. An average 3D offset of 1.43 mm was observed at the coronal aspect, with a little higher average offset of 2.04 mm at the implant apex. Also, the average angular deviation was 5.17°. There was no significant difference found between the post-operative methods of assessment. Significant differences were shown between implant A and B when comparing the depth of placement. Differences were also found between BL and BLT implant types in angular deviation and in the mesial/distal direction at the platform of the implant. When the guide required adjustments, a significant difference in positioning was found in the buccal/lingual direction.;Conclusions: Post-operative assessment using a CBCT or IOS of scan bodies are comparable methods to evaluate planned versus placed implant positioning. Flexure of the surgical guide may have caused implants placed further from the tooth support to be positioned deeper than planned. BLT implants showed better angular accuracy than BL implants with a partially guided surgical approach. The accuracy of implant positioning utilizing a digital workflow in this study was found to be consistent with findings in the literature.

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