A influência da broca plana em cirurgia de implantes parcialmente guiada

Abstract

Introduction: Partially guided implant surgery aims to increase the clinical accuracy of surgical procedures. The main objective of this study was to evaluate the impact of the milling cutter drill on the spatial accuracy of Bone Level (BL) implant placement within a partially guided surgical protocol. Secondarily, the study aimed to assess the influence of bone density and implant macrogeometry on the primary stability of implants. Materials & Methods: A total of 120 implants (Straumann® BL, BLT, and BLX) were placed into homogeneous polyurethane blocks simulating four bone density levels (D13D4). Implant placement was carried out using 3D-printed surgical guides following a partially guided protocol, with or without the use of the milling cutter drill. Deviations between the virtually planned positions on coDiagnostiX® software and the final implant positions were evaluated using the "Treatment Evaluation" tool, measuring three-dimensional and angular deviations at the implant's coronal and apical levels. Statistical analysis was performed with the software IBM® SPSS® Statistics v. 24., with significance set at p<0,05. Results: In a general analysis, the greatest three-dimensional deviations were observed at the apex (0.88mm) compared to the implant neck (0.56mm), in the absence of the milling cutter drill. The use of the milling cutter drill significantly reduced the angular deviation in implant placement (from 3.40° to 2.45°; p=0.007). Regarding bone density, although no significant differences were found in angular deviation, it was higher in D4 bone (3.60°). Significant differences were recorded at the implant neck both three-dimensionally (p=0.027; D3 bone=0.40 mm; D1 bone=0.99 mm) and linearly in the mesio-distal (p=0.036; D2/D3 bone=0.08 mm; D1 bone=0.12mm) and bucco-lingual directions (p<0.001; D3 bone=0.06 mm; D1 bone=0.58 mm). At the implant apex, significant differences were found only for linear deviations in the apico-coronal direction (p=0.005), with higher values in D1 bone and lower values in D3 bone (0.84mm and 0.46mm, respectively). In terms of implant macrogeometry, no differences were observed in angular deviations between the implant types studied. At the implant neck, BLX implants exhibited significantly greater deviations in three-dimensional (p=0.001; 0.91mm), bucco-lingual (p=0.02; 0.25mm), and apico-coronal (p=0.032; 0.70mm) directions. At the apex, BLT implants showed greater deviations in all parameters, although statistical significance was only reached in the bucco-lingual direction (p=0.045; 0.49mm). Conclusions: The milling cutter drill improves the angular accuracy of implant placement in partially guided protocols, while maintaining linear precision levels comparable to conventional procedures. Although bone density and implant macrogeometry do not significantly affect angular deviations, they are important variables to consider in implant surgery planning, as they may influence both three-dimensional and linear deviations at the neck and apex of the implant.

Date of Award	18 Jul 2025
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Patrícia Fonseca (Supervisor) & Catarina Fonseca (Co-Supervisor)