Reducing the manual length setting error of a passive Gough-Stewart platform for surgical template fabrication using a digital measurement system

As recently demonstrated, a passive Gough-Stewart platform (a.k.a. hexapod) can be used to create a personalized surgical template to achieve minimally invasive access to the cochlea. The legs of the hexapod are manually adjusted to the desired length, which must be read off an analog scale. Previous experiments have shown that manual length setting of the hexapod’s legs is error-prone because of the imprecise readability of the analog scale. The objective of this study is to determine if integration of a linear encoder and digitally displaying the measured length help reduce the length setting error. Two experiments were conducted where users set the leg length manually. In both experiments, the users were asked to set the leg length to 20 nominal values using the whole setting range from 0 mm to 10 mm. In the first experiment, users had to rely only on the analog scale; in the second experiment, the electronic display additionally showed the user the actual leg length. Results show that the mean length setting error without using the digital display and only relying on the analog scale was (0.036 ± 0.020) mm (max: 0.107 mm) in contrast to (0.001 ± 0.000) mm (max: 0.002 mm) for the experiment with the integrated digital measurement system. The results support integration of digital length measurement systems as a promising tool to increase the accuracy of surgical template fabrication and thereby patients’ safety. Future studies must be conducted to evaluate if integration of a linear encoder in each of the six legs is feasible.

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

The aim of this study was to evaluate the accuracy and feasibility of flapless implant placement using a light-cured surgical template made of composite resin comprising dimethacrylate and diurethane, performed simultaneously with crestal sinus augmentation. This pilot study was a prospective, single-armed, controlled clinical trial. Four patients having an edentulous region in the posterior maxilla with 4 to 8 mm of residual ridge height were enrolled. Flapless fully-guided implant placement was performed using a zero-setup surgical template with simultaneous crestal sinus graft. Horizontal, vertical, and angular deviations of the placed implants from the planned positions were measured. Clinical observations were made, and implant stability was measured up to 3 months postoperatively. All four implants were placed and maintained successfully without complication. The mean deviations of the four implants were 1.27 and 1.85 mm horizontally at platform and apex, respectively, 0.84 mm vertically at apex, and 4.76° in angle. Satisfactory implant stability was obtained in all implants at placement and 3 months. Fully-guided implant placement and crestal sinus graft using a zero-setup surgical template can be a safe and feasible method with acceptable accuracy. A randomized controlled trial should be performed in the future to validate its clinical performance in terms of surgical time, accuracy, and patient-reported outcomes.

ADVANTAGES AND DISADVANTAGES OF DIGITAL SURGERY IN DENTAL REHABILITATION. LITERATURE REVIEW WITH A DESCRIPTION OF THE CLINICAL CASE

Subject. With the advent of advanced imaging technology and CAD/CAM technologies, the possibility of guided surgery has become of wide interest among implantology. The article is devoted to the use of surgical template implantation in the rehabilitation of a dental patient. It provides information about some advantages and disadvantages of the digital protocol in comparison with traditional dental implantation. The main stages of navigation surgery in a clinical case are described. Goal. To evaluate the actual clinical advantages and disadvantages of dental implant placement using a surgical template compared to the traditional treatment protocol. Methodology. The literature search was conducted in scientific search bibliographic databases such as PubMed, eLIBRARY, Medline, and Google Academy. More than 384 studies up to 2014 were found under the thematic headings "Dental implantation" and "Surgical template". During the study of these works, the sample included 56 articles and literature reviews. Conclusions. Recently, implant placement using a surgical template has become a popular treatment method among dental surgeons. The study of modern literature allowed us to formulate the main advantages and disadvantages of this method. Advantages of the method: precise positioning of implants; flap-free surgery reduces the operation time and is characterized by a favorable postoperative course; integration of restoration determinants in surgical planning, which leads to a more aesthetic, functional and predictable result of prosthetics; the possibility of pre-manufacturing a prosthesis based on the planned position of the implant; simplification of the surgical procedure for the dentist. However, this method is not without its drawbacks: the surgeon's inability to visualize anatomical structures; the risk of axis and depth deviation during implant placement; requires additional digital planning.

The Influence of Different Guided Bone Regeneration Procedures on the Contour of Bone Graft after Wound Closure: A Retrospective Cohort Study

The aim of this study was to evaluate the impact of different guided bone regeneration (GBR) procedures on bone graft contour after wound closure in lateral ridge augmentation. A total of 48 patients with 63 augmented sites were included in this study. Participants were divided into 4 groups (n = 12 in each group) based on different surgical procedures: group 1: particulate bone substitute + collagen membrane; group 2: particulate bone substitute + collagen membrane + healing cap, group 3: particulate bone substitute + injectable platelet-rich fibrin (i-PRF) + collagen membrane; group 4: particulate bone substitute + i-PRF + surgical template + collagen membrane. After wound closure, the thickness of labial graft was measured at 0–5 mm apical to the implant shoulder (T0–T5). At T0–T2, the thickness of labial graft in group 4 was significantly higher than the other three groups (p < 0.05). And group 4 showed significantly more labial graft thickness than group 1 and group 2 at T3–T5 (p < 0.05). Within the limitations of this study, the use of i-PRF in combination with the surgical template in GBR may contribute to achieving an appropriate bone graft contour after wound closure.