A Modified Technique for Simplifying Full-Arch Screw-Retained Implant Rehabilitation With Rapid Digital Conversion: A Case Report
In this case report, a new modified technique is described for an efficient, simple, and effective digital approach to immediate provisionalization of the implant-supported full-arch prosthesis. Today’s patient population is increasingly educated about treatment options and expects efficient, esthetic, and comfortable results. This novel technique delivers on these aims while eliminating the many challenges posed by previously described digital and analog techniques to the immediate provisionalization of the implant-supported full-arch prosthesis. This technique requires minimal chair time and cost to the provider and reduces patient discomfort and complication risk. This technique therefore presents a promising new protocol for this popular procedure.
A custom tooth-borne guide was fabricated using implant-planning software and then milled. Osteotomy guide holes ensure ideal angulation of osteotomies according to available bone volume and desired prosthetic tooth placement. Windows included on the occlusal surface of the guide allow the provider to confirm the complete seating of the guide during surgery.
Innovative resin-based “S plates” provide an efficient alternative method to the chairside creation of a resin jig on multiple impression copings. These plates were prepared before surgery through simple 3D printing. They contained apertures that allowed them to be seated onto impression copings at the time of impression. Their material properties allowed for easy adjustment of the chairside and effective luting together with pattern resin. This process was completed in a fraction of the time required for traditional techniques of resin jig fabrication.
(a-d) An accurate impression was obtained using the open-tray technique. Impression copings were placed on multi-unit abutments. S plates were seated onto the copings and luted together with pattern resin. (e, f) Polyvinyl siloxane putty and light-body wash were applied to impression copings luted together via a resin jig. After adequate material setting time, the copings and impression were removed together, yielding an accurate impression of implant positions and soft tissues.
A verified and quick-setting model was fabricated from the previously obtained impression. Analogs were attached to impressing copings and luted using S plates and light-cure pattern resin. A model was then quickly manufactured using quick-setting cold-cure resin material. The finished model accurately recorded implant positions and soft tissues and required minimal fabrication time before use.
The anterior scanning device is a custom, fixed occlusal device made chairside by the dentist, which provides a repeatable occlusion position and allows recording of the jaw relationship, VDO, and the midline of the edentulous arch by a digital scanner. This device not only worked on recording ideal occlusion, VDO, and midline but also enabled the seamless merging of scans from the intraoral and extraoral environment. VDL indicates vertical dimension of occlusion.
The ASD can be fabricated by customizing it for each patient. In this case, an immediate denture was prepared ahead of surgery based on preoperative digital scan data. The immediate denture was then relined on 2 implant-supported copings to achieve a fixed position. The flanges and all material posterior to the incisors were then removed. Once only the anterior scanning device remained, the occlusion, VDO, and midline were evaluated and adjusted as needed before final scanning. ASD indicates anterior scanning device.
Remarkably, the ASD allowed for an intraoral scan of the edentulous arch in an ideal occlusion at the desired VDO and with the proper midline recorded. Before the development of this technique, these details were complicated, if not impossible, to record within one intraoral scan of the edentulous arch.
After beginning to scan the ASD intraorally, the ASD was removed from the oral cavity and transferred to the model to allow for completion of the scan of the arch of interest extraorally. This allowed the scanner to obtain precise data on the soft tissues and implant positions outside of the mouth while retaining the information about proper occlusion, midline, and VDO provided by scanning the ASD intraorally.
(a) The model of the arch-of-interest was scanned extraorally by the desktop scanner. (b) This scan was then quickly and automatically merged with the data gathered in the intraoral scan. Merging of scan data information obtained intraorally and extraorally was seamless, as the 2 scans captured an identical model. The intraoral scan included occlusion, VDO, and midline information but potentially lacked accuracy. The extraoral scan was more accurate and included information on implant position but lacked information on jaw relationship and midline. Merging these 2 scans combined their best aspects to create a new, single STL file containing all the required information for accurate prosthesis design.
The highly accurate and useful data obtained over the course of the described method rendered the digital design of the full-arch implant-supported FP3 prosthesis simple and efficient.
A full-arch implant-supported PMMA prosthesis with excellent esthetics, comfort, and fit accuracy was delivered 1 day postsurgery with minimal adjustment needed. The accuracy and efficiency with which this prosthesis was made would only be possible with the novel technique described in this report.
A summary of the procedure used in this case. Utilization of this innovative approach to conversion of the implant full-arch empowers the provider with the strengths of analog and digital methods and improved speed and outcomes.
Contributor Notes