International Journal of Computerized Dentistry, 02/2018

Implant placement requires precise planning and execution to avoid collision with critical anatomical structures. Technology advances may improve placement outcomes. The purpose of this study was to trial and measure in an in vitro environment the accuracy of placing a single dental implant in the planned position using a specific guided surgery technique compared with a freehand surgery technique. The dental model of a patient missing tooth 16 was printed 30 times (EnvisionTEC 3Dent). Each print was scanned (TRIOS color scanner) to create a 3D surface model, and radiographed (Gendex CB-500) to create cone beam computed tomography (CBCT) data. The surface data and CBCT data were merged (Implant Studio software), and a Straumann RC bone level Ø 4.1 × 8 mm implant placement was planned. A surgical guide was printed (Stratasys OrthoDesk) for each case (n = 30). Simulated cases were assigned to Group A (guided) or Group B (freehand, where the fabricated guide was discarded). Implants were placed, and the models rescanned (TRIOS). The new data was superimposed on the original data, and the surgical implant location compared with the planned position for each model (Convince software) by a researcher blinded to group allocation. Differences in angulation (degrees); shoulder, apex, and depth displacements (mm); and direction of displacement were assessed with Mann-Whitney U and Fisher exact tests. Data was expressed as medians bounded by interquartile ranges (IQRs). Implant angulation and apical displacement were significantly closer to the planned position in the guided group compared with the freehand group (3.91 degrees: IQR 2.45 to 5.38 degrees vs 8.82 degrees: IQR 4.84 to 9.84 degrees, P = 0.005; and 0.87 mm: IQR 0.53 to 1.11 mm vs 1.48 mm: IQR 1.14 to 1.72 mm, P < 0.001, respectively). Implant shoulder displacement, depth displacements, and direction of displacement did not differ between the groups. Within the in vitro environment, merged 3D surface scan data and 3D CBCT scan data can be used to plan and guide implant placement with greater accuracy than with the freehand technique. Keywords: cone beam computed tomography, computer-aided design (CAD), dental implants, three-dimensional imaging, three-dimensional surface scanning, patient care planning

Objective: The insertion of implants through template-guided surgery is an established method. At the present time, the static navigation is based on sleeves integrated into the guides, through which drill bits of the corresponding size are passed. The present clinical trial is designed to test a new sleeveless system to determine the precision of implant insertion for one-piece ceramic implants. Materials and methods: For 12 patients, implant bed preparation and the insertion of the implants were done using a sleeveless implant guide. Twenty implants were inserted in this way and checked for precision. The check was done using a noninvasive method, which permitted comparison of the planning data with the actually realized positions after superimposition. Results: The mean deviations were 0.52 mm (95% CI: 0.37 to 0.67 mm) at the crestal position of the implant, and 0.82 mm (95% CI: 0.56 to 1.08 mm) at the apical tip of the implant. The height deviation was 0.35 mm (95% CI: 0.01 to 0.68 mm). The mean angular deviation was measured as 2.85 degrees (95% CI: 2.18 to 3.51 degrees). Conclusion: The values showed good precision in all the parameters measured. The results were thus in a range equal to or better than the mean precision found in numerous clinical trials described in the literature. In particular, the method showed little deviation, as illustrated by the confidence interval (CI), but also by the clinically critical maximum deviations. Keywords: implant planning, guided surgery, drill guide, sleeve, sleeveless, accuracy, one-piece ceramic implant

Objective: This study evaluated the accuracy (trueness and precision) of dental models fabricated using additive manufacturing (AM) methods such as PolyJet and fused deposition modeling (FDM). Materials and methods: 10 stone models were acquired for the control group by scanning a complete arch model. For the experimental groups, 10 PolyJet models and 10 FDM models were fabricated from digital impressions using an intraoral scanner. All 30 models were then scanned, and root mean square values were measured using three-dimensional (3D) analysis software. Results: Trueness did not significantly differ between the stone and PolyJet models. The precision of the AM models was significantly higher than that of the stone models. The layer thicknesses of the FDM models were greater than those of the PolyJet models. Conclusion: The results of this study show that it might be possible for the dental models fabricated using additive manufacturing methods to be used in clinical settings. Keywords: accuracy, trueness, precision, additive manufacturing, dental model, 3D printing

The irreversible trend toward digitization in dentistry and dental technology has resulted in technical progress and continuous changes to conventional workflows. In particular, implantology and prosthetics have benefited from a multitude of interesting new possibilities. Three-dimensional (3D) computed radiography and digital surface scanning can be invaluable in terms of backward planning and making implant surgery and denture fabrication more predictable. In this context, two digital implant-prosthetic treatment strategies are presented that allow for an efficient digital workflow while ensuring a minimally invasive surgical procedure. By means of digital intraoperative scanning of the implant position, the digital one-abutment/one-time concept allows for the insertion of computer-aided design/computer-aided manufacturing (CAD/CAM)-manufactured single crowns instantly after uncovering the implant. The second approach uses 3D radiographic data to preoperatively manufacture a one-piece root-analogue implant (RAI) and insert it immediately after tooth extraction. Both ideas promise some advantages in terms of quality and preservation of periimplant tissues as well as a noticeable reduction in overall treatment time. Keywords: computer-aided design/computer-aided manufacturing (CAD/CAM), custom-made implant, cone beam computed tomography (CBCT), guided surgery, immediate implantation, intraoral scanning (IOS), root-analogue implant (RAI), one-abutment/one-time, three-dimension

The rehabilitation of the edentulous jaw using angulated implants and screw-retained retrievable fixed prosthetic dentures is a well-established treatment method. Possible advantages include the option to avoid bone augmentation, to provide an immediate long-term provisional restoration, and, where appropriate, to perform a minimally invasive procedure. A variety of prosthodontic solutions are available for the definitive restoration, not least allowing the patient's financial situation to be accommodated. Implementing this concept requires systematic planning and an exacting surgical procedure. It makes sense to rely on a computer-assisted process for this purpose as it standardizes the procedure and makes it reproducible, with all the benefits this entails. The present report highlights the consistent integration of virtual planning and computer-aided design/computer-aided manufacturing (CAD/CAM), from the surgical template to the immediate long-term provisional restoration. The relevant procedures are described in general terms and illustrated by a patient case. Keywords: CAD/CAM, computer-guided implant placement, digital workflow, edentulous jaw, immediate loading, minimally invasive implantation, surgical template

Three-dimensional (3D) implant positioning is an important prognostic factor for anterior dental implants. Modern 3D imaging and implant treatment planning systems are available today for precise dental implant planning and placement. The transfer of implant position information to industrially manufactured templates for guided implant surgery has been possible for years now. What is new is the possibility of combining the datasets with the surface scan data of a diagnostic wax-up and setup for prosthetic-driven implant planning. Digital setups can also be used. This article describes and discusses the available options for digital implant planning and guided surgery. Keywords: dental implantology, anterior implant, implant position, cone beam computed tomography, CAD/CAM surgical guide, 3D printing, complications

The development of titanium bonding bases allows for the use of implant-supported monolithic reconstructions in a digital workflow. Different base configurations are available according to each clinical indication. In this case report, the selection of titanium bonding bases for crowns was considered for a multiple-unit fixed dental prosthesis (FDP). Keywords: CAD/CAM, digital workflow, implant-supported reconstruction, monolithic zirconia, titanium bases