Accuracy of implant according to support type of dental implant surgical guides: A retrospective study

Purpose: This study evaluated the influence of surgical guide support type on implant placement accuracy by comparing planned and actual implant positions.Materials and Methods: Thirty-two patients who underwent guided implant surgery between January 2024 and April 2026 were included. 136 implants were analyzed: 60 in 9 edentulous patients and 76 in 23 partially edentulous patients. CAD/CAM surgical guides were fabricated using preoperative CBCT and intraoral scan data. Postoperative CBCT images were superimposed on planning data to measure coronal, apical, depth, and angular deviations. Guides were classified as tooth-supported or tissue-supported, with tooth-supported guides further categorized as unilateral or bilateral. Implant sites were classified as anterior, premolar, or molar.Results: Tooth-supported guides showed lower coronal and apical deviations than tissue-supported guides (1.48 ± 0.09 vs. 1.95 ± 0.14 mm, p = 0.006; 1.85 ± 0.12 vs. 2.28 ± 0.15 mm, p = 0.030). Depth and angular deviations did not differ significantly. No significant differences were found between unilateral and bilateral tooth-supported designs. Implant location did not affect coronal, apical, or depth deviations but affected angular deviation. In tooth-supported guides, molar implants showed greater angular deviation than premolar implants (p = 0.031), whereas in tissue-supported guides, anterior implants showed greater angular deviation than premolar and molar implants.Conclusion: Tooth-supported surgical guides provided greater implant placement accuracy than tissue-supported guides, particularly for coronal and apical deviations. Guide stability and implant site characteristics should be considered to improve the accuracy and predictability of guided implant surgery.