Accuracy of Tooth-Supported Surgical Guides According to the Number of Supporting Teeth in Dental Implant Placement

Purpose: This study evaluated the accuracy of computer-aided design and manufacturing (CAD/CAM)-fabricated stereolithographic surgical guides according to the number of supporting teeth in patients with partial edentulism undergoing implant placement. Materials and Methods:The experimental group consisted of maxillary and mandibular arches with only three remaining teeth per arch arranged in a triangular distribution (anterior, left posterior, and right posterior) without adjacent contacts.The control group comprised arches with seven or more remaining teeth per arch, allowing adjacent contacts.Implant placement was performed at edentulous sites, with three implant sites designated per maxillary and mandibular model, using CAD/CAM-fabricated surgical guides.Results: No statistically significant differences were observed between the groups with respect to distance and angular errors.When evaluating the minimum distance between the two central axes, the mean error was 0.16 0.17 mm for guides supported by seven or more teeth and 0.20 0.12 mm for guides supported by three teeth.When assessing the angular deviation of the implant axis, the mean error was 3.02 2.05 in the group with guides supported by seven or more teeth and 3.41 2.64 in the group with guides supported by three teeth. Conclusion:This in vitro study demonstrated that using tooth-supported CAD/CAM surgical guides for implant placement in partially edentulous cases with only three remaining teeth resulted in no significant deviations.This study provides a basis for the application of digital implant surgical guides in clinical practice, particularly in cases with limited remaining teeth for support.