Date of Award
Spring 2024
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Dentistry
First Advisor
Arndt Guentsch
Abstract
BACKGROUND: Esthetic and functional results of an implant and its final prosthesis depend largely on the accuracy of implant placement. Fully-guided surgeries have been proven to be more accurate than non-guided implant placement. Surgical guides with metal keys are often used during guided surgery, but add tolerance to the guides. Sleeveless guides may improve accuracy of implant placement. OBJECTIVE: This study aims to examine the difference between surgical guides with (S) and without sleeves (SL) in terms of trueness and precision. A secondary aim was to assess the impact of the distance of the guide to the implant platform. METHODS: Mandible replicas (n=120) were printed from an STL file obtained from a clinical CBCT. The mandibles were divided into a sleeved group (S, n=60) and sleeveless group (SL, n=60). Each group was further divided into three categories (n=20 each), each with different heights from the guide to the implant platform: 2 mm (H2), 4 mm (H4), or 6mm (H6). Digital implant planning and surgical guide design was done for a 4.1x10 mm implant for site #30. A print matrix served to determine the best fit of the surgical key in the sleeveless guide cylinder. Once the implants were placed, the post-op position was captured using a scan body and a lab scanner, and pre-op planning and post-op positions were compared. The angular deviation was defined as the primary outcome parameter and 3D and 2D deviations in mm were secondary parameters. Statistical analysis was performed via a two-sample t-test, one-way and two-way ANOVA. RESULTS: Group S (2.41±1.41o) had a statistically significant greater angular deviation than Group SL (1.651±0.93o; p = 0.0001). The closer the distance to the implant platform, the lower the angular deviation and therefore the higher the accuracy. The mean angular deviations for H2 were1.48 ± 0.80o ¬for Group S vs. 1.02±0.45o for Group SL (p<0.05). The same pattern was found for H4 (S: 2.36±1.04o vs. SL: 1.48±0.79o; p<0.05) and H6 (S: 3.37±0.67o vs. 2.46±0.89o; p<0.05). The 3D deviation at the implant platform was for Group S 0.36±0.17mm and Group SL 0.30±0.15mm (p<0.05) and at the apex 0.74±0.34 (S) vs. 0.53±0.31mm (SL; p<0.01). Group SL at H2 had the smallest distance between implants (0.53 ± 0.37o) while Group S at H4 had the largest distance between implants (1.20 ± 0.84o; p<0.05). CONCLUSION: Sleeveless guides are more accurate than sleeved guides in terms of trueness and precision. Angular deviation is also affected by the distance of the guide to the implant platform.