Date of Award
Spring 2022
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Dentistry
Program
Periodontics
First Advisor
Guentsch, Arndt
Second Advisor
Kassab, Moawia
Third Advisor
Kofina, Vrisiis
Abstract
Purpose: The aim of this study was to evaluate the influence of type of tooth-support (bounded edentulous space versus unbounded edentulous spaces) on the accuracy of fully-guided implant placement using static computer-assisted implant surgery (sCAIS) in partially-dentate patients. Methods: Four different clinical scenarios were simulated; (a) bounded single-tooth edentulous space (BES), and three different free-end distal extensions with (b) unbounded single-tooth edentulous space (UBES1), (c) unbounded two-teeth edentulous space (UBES2), and (d) unbounded three-teeth edentulous space (UBES3). An implant planning software was used to design 3D-printed stereolithographic surgical guides for the respective clinical scenarios. In total n=140 implants with dimensions 4.1x10mm (n=20 per tooth site) were placed in n=80 identical mandible replicas. The achieved implant positions were digitized by using a laboratory scanner and compared with the planned positions. Trueness (planned versus actual position) and precision (difference among implants) were determined. The angular deviation was defined as the primary outcome parameter, and mesial-distal, buccal-lingual, and coronal-apical deviations as secondary parameters. The means, standard deviation, and 95%-confidence intervals were analyzed statistically with 1-way ANOVA and the Scheffé procedure. Results: sCAIS showed the highest trueness (planned versus actual position) in a bounded edentulous space with 1.36±0.41° angular deviation and the lowest trueness for an unbounded three-teeth edentulous space with 2.71±1.20° angular deviation (P <0.001). There was no statistical difference between BES and UBES1 2.00±0.68° (P =0.19), but there was significant difference between BES and UBES2 (2.42±0.71°; P < 0.001). The angular deviations of UBES1 and UBES2 were not statistically different (P =0.43), but UBES1 and UBES3 showed statistically significant differences (P = 0.03). The precision was highest for BES with 0.47±0.68° and lowest among implants in the UBES3 group with 1.27±1.10° (P < 0.001). UBES1 and UBES2 are comparable regarding precision with 0.80±0.0.60° for UBES1 and 0.81±0.65° for UBES2 (P = 0.998). Conclusions: The accuracy of sCAIS is impacted by the type of tooth support. The highest accuracy in terms of trueness and precision can be achieved in a bounded edentulous space. An increase in the span of the free-end edentulous space for additional planned implants (≥2) decreased the accuracy of placement.