SupplementPages 49-57e, Language: EnglishSchneider, David / Sancho-Puchades, Manuel / Benic, Goran I. / Hämmerle, Christoph H. F. / Jung, Ronald E.The objectives of this study were to compare conventional and computer-assisted implant planning and placement (CAIPP) protocols regarding surgical planning predictability, intraoperative complications, and patient-centered outcomes. Partially edentulous patients (N = 73) were randomly allocated to one of three treatment groups: control (C, n = 26), with preoperative planning based on conventional radiography and freehand implant placement; and test 1 (T1, n = 24) and test 2 (T2, n = 23), with two different CAIPP protocols. The clinicians' predictions of the bony morphology, materials needed for surgery, and surgery duration were matched with intrasurgical findings using kappa tests. Complications or deviations from the surgical or prosthetic protocol were recorded. Descriptive statistics were used to study the sample sorted out by treatment group. Differences between groups were evaluated with chi-square test for qualitative variables and with nonparametric Kruskal-Wallis test for quantitative continuous variables. For post-hoc tests, the Bonferroni corrected (P .016 = .05/3) Mann-Whitney test was used. CAIPP protocols showed better diagnostic potential than conventional protocols for the bone topography, need for simultaneous GBR procedures, membrane selection, and implant length predictions. The rate of surgical protocol deviations was similar in all groups, but their nature differed. Conventional protocols showed fewer splint-related incidences. Implant bed preparation and insertion could not be fully completed using the surgical splint in 3.8% of patients in C (1/26), 45.8% in T1 (11/24), and 47.8% in T2 (11/23). Deviation from the initial prosthetic plan was necessary in one case (T2; 4.4%). No biologic or technical complications were observed. CAIPP protocols showed a higher diagnostic potential than conventional protocols. A high incidence of intraoperative surgical protocol modifications to adjust suboptimal implant placements was reported for every group. Therefore, strict intraoperative implant position monitoring is mandatory for both treatment protocols.