The Impact of Surgical Guide Fixation and Implant Location on Accuracy of Static Computer‐Assisted Implant Surgery

Abstract

Purpose: To evaluate the accuracy of static computer-assisted implant surgery (sCAIS) for tooth-supported free-end dental implantation with the aid/and without the aid of fixation pins to secure the surgical template through comparison between planned, 3D printed guide position and placement implant position. Materials and Methods: Thirty-two duplicated maxillary resin models were used in the present in vitro study. Digital planning was performed and fabrication of a surgical template that allowed implant placement on the distal extension edentulous site of the model (maxillary left side). A first optical scan was performed after fitting the surgical template on the model to assess the deviation at the surgical guide level. After placing implants in the model using the surgical guide, scan bodies were attached to the implants, and a second scan was performed to record the position of placed implants. The digital representations were later superimposed to the pre-operative scan and measurements of implant deviations were performed. Global (coronal and apical), horizontal (coronal and apical), depth and angular deviations were recorded between planned implant position, guide position, and placement implant position. Three-way ANOVA was used to compare implant location (#13, 14, and 15), fixation pin (with or without pin), and guide comparison (planned, guided, and placement). Results: Final implant placement based on the digital plan and based on the 3D printed guide were very similar except for depth deviation. Use of fixation pin had a statistically significant effect on the depth and angular deviation. Overall, without fixation pins and based on guide versus placement, mean global coronal (0.88 ± 0.36 mm), horizontal coronal (0.55 ± 0.32 mm), and apical (1.44 ± 0.75 mm), and angular deviations (4.28 ± 2.01°) were similar to deviations with fixation pins: mean global coronal (0.88 ± 0.36 mm); horizontal coronal (0.67 ± 0.22 mm) and apical (1.60 ± 0.69 mm); and angular deviations (4.53 ± 2.04°). Horizontal apical without pins (1.63 ± 0.69 mm) and with fixation pins (1.72 ± 0.70 mm) was statistically significant (p = 0.044). Depth deviation without pins (-0.5 ± 0.5 mm) and with fixation pins (-0.16 ± 0.62 mm) was also statistically significant (p = 0.005). Further analysis demonstrated that the final sleeve position on the 3D printed guide was on average 0.5 mm more coronal than the digital plan. Conclusions: The use of surgical guides with or without fixation pins can provide clinically acceptable outcomes in terms of accuracy in implant position. There was a statistically significant difference in the accuracy of implant position when utilizing fixation pins only for horizontal apical and depth deviation. Additionally, a statistically significant difference between the planned and the 3D printed surgical guide when considering the sleeve position was detected.

The influence of guide stabilizers and their application sequences on trueness and precision of surgical guides in free end situations: An in vitro analysis

“…One of the most effective ways to reduce the mobility of the templates is to provide rigid support at the far free end (Al-Omiri et al, 2017), including fixation pins (Chen et al, 2023;Pessoa et al, 2022;Raico et al, 2017), bone support spot (Lin et al, 2020), and anchor microscrew-cap system (Mai & Lee, 2020). Chen Xi et al found that the group without fix pin generated the Angle deviation (3.65 ± 1.39°), 3D deviation at crest (1.58 ± 0.55 mm), and 3D deviation at apex (2.18 ± 0.79 mm), whereas the group with bilateral fixation pins on the buccal and palatal sides significantly reduced the Angle deviation to 1.88 ± 0.86°, 3D deviation at crest to 1.09 ± 0.51 mm and 3D deviation at apex to 1.53 ± 0.45 mm (Chen et al, 2023;Raico et al, 2017).…”

“…When the surgical guide is not supported firmly enough, the transmitted force could result in positional deviation or dislodgement of the surgical guides (Lee et al., 2016; Seo & Juodzbalys, 2018). One of the most effective ways to reduce the mobility of the templates is to provide rigid support at the far free end (Al‐Omiri et al., 2017), including fixation pins (Chen et al., 2023; Pessoa et al., 2022; Raico et al., 2017), bone support spot (Lin et al., 2020), and anchor microscrew‐cap system (Mai & Lee, 2020). Chen Xi et al.…”

“…The material density of the model was uniform in each implant site, but in the human body the bone density of the implant site may be heterogeneous. According to the operator's understanding and tactile feeling that, without intervention (group A), the implant tried to follow the path of the least resistance in the bone tissue, often showing a bigger discrepancy to the guide orientation (Pessoa et al., 2022). Thirdly, the elasticity of soft tissues, determined by their quality and quantity, was a factor that influences the accuracy of implant placement (Ochi et al., 2013), while homogeneous and relatively rigid materials were used to simulate the gingiva in this study.…”

Computer-Assisted Dental Implant Placement Following Free Flap Reconstruction: Virtual Planning, CAD/CAM Templates, Dynamic Navigation and Augmented Reality

“…Implants in distal extension gaps resulted in more significant deviation when compared to implants placed in posterior areas with adjacent bilateral teeth support due to possible intraoperative guide movement, tilting, and bending, particularly in long cantilever lengths. Although the mismatch between the planned and final achieved positions can be measured, no information on the source of inaccuracy can be assessed (38). Most of our patients belonged to the group of long posterior extension gaps prone to bending and tilting of the static guide.…”

Additive manufacturing technologies in the oral implant clinic: A review of current applications and progress

“…Regarding other factors that influence template accuracy, Zhou et al (Zhou et al, 2018) conducted a comprehensive comparison of various clinical factors and concluded that guide accuracy may be affected by guide position (maxilla or mandible), guide fixation (fixation screw or not) (Pessoa et al, 2022), type of guide (total or partial) (Mangano et al, 2018;Lou et al, 2021;Fotopoulos et al, 2022;Gargallo-Albiol et al, 2022), flap approach (open flap or flapless), differences in implant system (Zhu et al, 2021), high temperature sterilization (Marei et al, 2019;Kirschner et al, 2022) and support mode (tooth-supported, mucosa-supported or mixed-supported) (Pan et al, 2022). In addition, Henprasert et al concluded that there was no significant difference in accuracy between 3D-printed and milled guides, but found that the former had the advantages of high efficiency and reduced material waste (Henprasert et al, 2020).…”