ABSTRACT

Standard planning for dental implants consists of a prosthesis simulation on diagnostic casts and radiographic examination of anatomical structures. The clinician visually locates the planned trajectory on the surgical site in the patient’s mouth without direct correlation between the radiographs and the anatomy. We have developed a computer assisted technique to define the optimal position of the bone implant using computed tomography to accurately place the implant in the planned position using a guide drilled into a resin splint.

ABSTRACT

This paper presents a simple method and new material which allow transferring results of surgical planning - such as the implant fixture axis - to the surgical site. This method is based on drilling a linear guide in a resin splint corresponding to the fixture axis. A simple mechanical setup links the Computed Tomography (CT) data set with the drilling machine. Since the optimal fixture axis is determined with a software interface, it can be transferred as a linear guide to the resin splint with the drilling machine. Technical validation demonstrates that the accuracy of the method is 0.2 mm in translation and 1 degree in rotation. These results provide a high level of accuracy and clinical validation has begun with several patients. The results for the patients are very satisfactory.

ABSTRACT

The use of medical imaging techniques to make a very precise surgical guide for implant placement is described. This template is the combination of a currently used template and a very simple mechanical system designed to transfer a preoperatively defined implant position onto the surgical site. With the planning software, the practitioner determines the implant position according both to the ideal position dictated by the final restorative prosthesis and the available volume of bone. The surgical template then communicates the actual implant position to the surgical site. The template can be used not only in critical anatomical situations but also in placing the implant in an ideal position on bone because it eliminates possible manual placement errors and matches planning to prosthetic requirements.

ABSTRACT

In this study, an image-guided system for oral implant placement was assessed. A specially designed mechanical tool has been elaborated to transfer the preoperative implant axis planned on 3-dimensional imagery into a surgical template by a numerically controlled drilling machine. The main drawback of image-guiding systems is the use of preoperative computed tomography, which is expensive and delivers high radiation doses. Therefore, in this study the image-guiding system was coupled with a cone-beam tomograph that significantly decreased both cost and radiation doses. Three edentulous models were used. To determine the accuracy of the system, the ability of a 1.8-mm diameter drill to enter a 2.0-mm diameter, 10-mm-long titanium tube inserted on the model with no contact was verified. Because the drill entered the tubes with no contact and went beyond the end of the tube, the transfer error was less than 0.2 mm for translation and less than 1.1° for rotation. The method presented here is low cost and high precision compared to other technological solutions such as tracking. Further assessment in the surgical field should lead to daily use of this system for flapless surgery to prepare a prosthesis prior to surgery for immediate loading, to reduce risk of injuring critical anatomical structures and to eliminate manual placement error.

ABSTRACT

Purpose: The purpose of this study was to assess the reliability of the planning software of an image–guided implant placement system based on a mechanical device coupled with a template stabilized on soft tissue during surgery. Materials and Methods: Thirty consecutive partially or completely edentulous patients were treated with the image-guided system. For each patient, a study prosthesis was fabricated and duplicated in acrylic resin and served as a scanning template. Axial images were obtained from a computerized tomographic scan and transferred to planning software that provides real 3- dimensional information to plan implant position. Once the final position of the implant was defined, preoperative data such as the size of implants and anatomic complications were recorded using the planning software. The scanning template was then drilled in that exact position by a drilling machine. During surgery, the drilled template was used as a drill guide. After implant placement, intraoperative data were recorded and statistically compared with the preoperative data using the Kendall correlation coefficient for qualitative data and the Kappa concordance coefficient for quantitative data. Results: Agreement between the preoperative and intraoperative data was high for both implant size and anatomic complications. The Kendall correlation coefficient was 0.8 for the diameter and 0.82 for the length. The Kappa concordance coefficient was 0.87 for both dehiscence and bone graft, 0.88 for osteotomy, and 1.0 for fenestration. Discussion: In the few instances where planning was not perfect, implant placement was completed in a clinically acceptable manner. Conclusion: The results suggest that the image-guided system presented is reliable for the preoperative assessment of implant size and anatomic complications. It may also be reliable for flapless surgery.

ABSTRACT

Background: With the use of computer–assisted surgery and other modern imaging technologies, the surgeon’s procedures have been modified. Purpose: The purpose of these case reports is to show the clinical predictability of dental implant placement using an image–guided system. Material and Methods: An acrylic template is made on the patient model. After computed tomographic examination, a treatment plan is established with appropriate software. To fabricate the surgical template, it is necessary to use a dedicated drilling machine. The first osteotomy is achieved through the template with a 2 mm twist drill. The template is then removed, and the osteotomy is completed, followed by implant placement with standard clinical procedures. Results: An excellent predictability was observed between the planned implants and those placed in the two maxillary cases presented: a full upper screw-retained bridge and two single units. Conclusions: This new technology improves the treatment outcome and optimizes the surgical procedure.

ABSTRACT

Purpose: An image-guided system has been developed to drill a conventional surgical guide following a preoperative three–dimensional plan for accurate placement of implant on bone. The aim of this study is to illustrate how this system facilitates treatment of completely edentulous patients by modifying both surgical and prosthetic protocols, thereby making flapless surgery possible as well as the preparation of the transitional prosthesis before surgery. Materials and Methods: This system was tested on 10 consecutive patients, placing all planned implants without raising the mucoperiosteal flap and with the connection of all implants to pre-angulated abutments. Results: A 1–year follow-up demonstrated stable and properly functioning prostheses in all cases. Conclusions: This technique can be expected to flourish because implantology makes the highest demands on comfort, precision, and safety.

ABSTRACT

Purpose: The aim of this study was to compare the pain experienced after implant placement with 2 different surgical procedures: a flapless surgical procedure using an image-guided system based on a template and an open–flap procedure. Materials and Methods: The study population consisted of 60 patients who were referred for implant placement. One group consisted of 30 patients who were referred for the placement of 80 implants and treated with a flapless procedure. The other group consisted of 30 patients who were referred for the placement of 72 implants with a conventional procedure. Patients were selected randomly. They were requested to fill out a questionnaire using a visual analog scale (VAS) to assess the pain experienced and to indicate the number of analgesic tablets taken every postoperative day from the day of the surgery (D0) to 6 days after surgery (D6). Results: The results showed a significant difference in pain measurements, with higher scores on the VAS with open-flap surgery (P <.01). Pain decreased faster with the flapless procedure (P = .05). The number of patients who felt no pain (VAS = 0) was higher with the flapless procedure (43% at D0 versus 20%). With the flapless procedure, patients took fewer pain tablets (P = .03) and the number of tablets taken decreased faster (P = .04). Discussion: Minimally invasive procedures may be requested by patients to reduce their anxiety and the pain experienced and thus increase the treatment acceptance rate. Conclusion: With the flapless procedure, patients experienced pain less intensely and for shorter periods of time.