Prospective Clinical Study on the Accuracy of Static Computer-Assisted Implant Surgery in Patients With Distal Free-End Implants. Conventional Versus CAD-CAM Surgical Guides.

Objectives: To compare the accuracy of CAD-CAM and conventional guides in the static computer-assisted implant surgery (sCAIS) placement of distal free-end implants.

Material and methods: A prospective, controlled, and blinded quasi-experimental study was done involving 27 patients (76 implants) distributed into two groups according to the surgical guide manufacturing approach used: conventional (control group [CG]) or CAD-CAM (test group [TG]). The implants were planned in the software and the surgical guides were manufactured. Fully guided implant placement was carried out and the deviations were measured along with secondary variables as potential confounding factors. Descriptive analyses were performed on mean, standard deviation (SD), and interquartile range (IQR). In the comparative/inferential analysis hypothesis, contrasts were made of the quantitative and qualitative variables and multiple linear models were generated to adjust for the different confounding variables recorded.

Results: Coronal horizontal deviation (CHD) was significantly greater in CG (1.52 mm) versus TG (1.04 mm) (p = 0.004). Apical horizontal deviation (AHD) in turn was 1.67 versus 1.46 mm, respectively; angular deviation was 2.87 versus 3.64; and vertical deviation was -0.1 versus -0.05 mm, with no significant differences between the groups (p > 0.05). A greater sleeve height, positioning in premolars versus molars, and the use of shorter implants, were associated with greater accuracy in relation to CHD and/or AHD (p < 0.05). The implant success rate at 1 year was 92.1%, 90.7% in TG, and 100% in CG, being statistically significant (p = 0.026) at the implant level, but not significant at the patient level.

Conclusions: The CAD-CAM surgical guides proved to be more accurate than the conventional guides in the sCAIS placement of distal free-end implants, with statistically significant differences being observed in terms of CHD. All implant failures occurred in TG (6 implants/3 patients).

Trial registration: ClinicalTrials.gov identifier: NCT06404385.