Positional accuracy during the sequence of static computer-assisted implant surgery in three alveolar ridge morphologies: An in vitro study.

Purpose: This in vitro study aimed to assess the positional accuracy during the sequence of static computer-assisted implant surgery (sCAIS) according to the anatomical characteristics of the alveolar ridge.

Material and methods: Maxillary bone models with six single tooth gaps including clinical scenarios of healed alveolar ridge (HR), single-rooted (SRS), and three-rooted socket (TRS) morphologies were used in this study. Positional deviations during implant placement procedures were evaluated after the pilot osteotomy (PD), final osteotomy (FD), and implant placement with respect to the pre-planned implant position by using a software package. ANOVA and post hoc analyses were performed.

Results: A total of 90 implants were included in this study. Higher mean angular, crestal, and apical deviations were found after the PD and FD (3.5 ± 2.4°, 0.7 ± 0.3 mm, and 1.4 ± 0.8 mm versus 3.6 ±2.2°, 0.6 ± 0.3 mm, and 1.2 ± 0.6 mm) compared to IP (2.8 ± 1.6°, 0.7 ± 0.3 mm, and 1.2 ± 0.5 mm, p ≤ 0.004). Implants placed in TRS demonstrated higher mean angular, crestal, and apical deviations (4.0 ± 1.7°, 0.8 ± 0.3 mm, and 1.6 ± 0.5 mm) compared to implants placed in SRS (2.5 ± 1.2°, 0.7 ± 0.3 mm, and 1.1 ± 0.4 mm) or HR (2.0 ± 0.9°, 0.5 ± 0.3 mm, and 0.8 ± 0.4 mm, p < 0.001).

Conclusions: Positional deviations during sCAIS procedures are initiated with the first implant osteotomy and persist throughout the drilling sequence. However, deviations slightly decreased after implant placement. The alveolar ridge morphology is strongly associated with positional deviations. Higher deviations were observed in three-rooted and single-rooted sockets simulating an immediate approach compared to healed sites simulating a delayed protocol.