Accuracy of Dental Implant Placement by a Novel In-House Model-Free and Zero-Setup Fully Guided Surgical Template Made of a Light-Cured Composite Resin (VARO Guide®): A Comparative In Vitro Study

Abstract

Background: This in vitro study mainly aimed to compare VARO Guide® to the surgical guide fabricated by CAD/CAM (NAVI Guide®) in terms of accuracy and efficacy of the implant surgery held in the dentiform model. Methods: Twenty surgeons, 10 dentists in the beginner group and 10 dentists in the expert group, participated in the study. Each surgeon conducted fully guided surgery in dentiform models twice, once with VARO Guide® (VG surgery) and the other time with a conventional type of templates, NAVI Guide® (NG surgery). Based on the superimposition of presurgical and postsurgical STL files, the positional deviations between the virtually planned and actually placed implants and the time spent on presurgical preparation and surgical procedures were estimated and compared. Results: All dimensional deviations were similar between the two groups (p > 0.05), and there was no significant difference between the expert and beginner groups regardless of the guide system. The total procedure time (mean (median)) of the VG surgery (26.33 (28.58) min) was significantly shorter than that of the NG surgery (378.83 (379.35) min; p < 0.05). While the time spent only for the fully guided implant surgery (from the start of the surgical guide sitting onto the dentiform model to the final installation of the implant fixture) was comparable (p > 0.05), the presurgical preparation time spent on virtual implant planning and surgical guide fabrication in the VG surgery (19.63 (20.93) min) was significantly shorter compared to the NG surgery (372.93 (372.95) min; p < 0.05). Conclusions: Regardless of experience, both VG and NG surgery showed reliable positional accuracy; however, the total procedure time and the preparation time were much shorter in the VG surgery compared to the NG surgery.

Accuracy and Feasibility of a Zero-Setup Implant Guide System Made of a Light-Cured Composite Resin with Simultaneous Flapless Sinus Augmentation: A Pilot Study

“…Extrinsic errors can result from the movement of the VARO guide during implant placement and the experience of the surgeon in the VARO guide protocol. In regards to the latter, however, a recent in vitro study has reported similar outcomes in terms of time and accuracy when VARO guide surgery was performed by expert and novice users [11]. In the same study, when the VARO guide was compared to a 3D-printed surgical guide, the VARO guide required less time to prepare, although the surgical time was similar.…”

“…In summary, the current system can be made inside a single facility (in-house), does not involve a model, be it conventional or digital (model-free), and requires just a milling machine and no laboratory work or a 3D printer (zero-setup). In our previous in vitro study using the VARO guide, a similar placement accuracy was shown compared to a conventional 3D-printed surgical guide; however, the preparation time was much shorter [11]. Now, there is a need to verify the feasibility and accuracy of the VARO guide clinically.…”

“…The fabrication of the VARO guide (Neobiotech, Seoul, Korea) is illustrated in Figure 1. The fabrication process of the VARO guide is described in detail in a previous study [11]. Following the initial visit of subject enrollment, the VARO guide was fabricated as follows.…”

“…The pre-guide was then retrieved from the mouth, and the biting surfaces were cured for an additional 30 s. Once cured, the pre-guide was repositioned in the mouth and CBCT (Q-FACE, HDX WILL, Seoul, South Korea) was taken (85 kV, 8 mA, and exposure time of 24 s) for both upper and lower jaws. The CBCT images were then transferred to a computer software The fabrication process of the VARO guide is described in detail in a previous study [11]. Following the initial visit of subject enrollment, the VARO guide was fabricated as follows.…”

“…The pre-planned fixture position was extrapolated from the position of the drilling hole and the postsurgical fixture position from the virtual abutment. This process of extrapolating the fixture position is known as "reverse engineering" and has been described in a previous study [11].…”