Christopher B. Marchack

CAD/CAM fabricated complete dentures: concepts and clinical methods of obtaining required morphological data

The clinical impression procedures described in this article provide a method of recording the morphology of the intaglio and cameo surfaces of complete denture bases and also identify muscular and phonetic locations for the prosthetic teeth. When the CAD/CAM technology for fabricating complete dentures becomes commercially available, it will be possible to scan the denture base morphology and tooth positions recorded with this technique and import those data into a virtual tooth arrangement program where teeth can be articulated and then export the data to a milling device for the fabrication of the complete dentures. A prototype 3-D tooth arrangement program is described in this article that serves as an example of the type of program than can be used to arrange prosthetic teeth virtually as part of the overall CAD/CAM fabrication of complete dentures.

Customization of milled zirconia copings for all-ceramic crowns: A clinical report

Generically milled zirconia copings for all-ceramic crowns may not provide optimal thickness and form for the coping or the porcelain veneer. This article describes the customization of milled zirconia copings to provide even and controlled porcelain thickness with the aim of decreasing cohesive porcelain fracture and other failures. A full-contour waxing and cut back in conjunction with a dual-scan technique was used to ensure adequate coping thickness, adequate, even porcelain thickness, and butt joints at the porcelain-to-coping junctions.

CAD/CAM-guided implant surgery and fabrication of an immediately loaded prosthesis for a partially edentulous patient

The treatment planning, placement, and restoration of dental implants for the partially edentulous patient can be challenging. Anatomical limitations can make implant location difficult to determine. The use of CT scans and surgical planning software to produce a CAD/CAM surgical template, as well as the use of a flapless surgical technique, can make implant placement more predictable, safer, and easier for patients. The article describes a computer-guided surgical technique for the partially edentulous patient, with a restoration fabricated prior to implant placement, for immediate loading.

Complete and partial contour zirconia designs for crowns and fixed dental prostheses: A clinical report

Since the introduction of milled zirconia copings for ceramic crowns, a variety of techniques have been introduced to reduce the incidence of chipping or fracturing of the porcelain veneer. These include methods of improving the interface between the coping and the veneer, reducing thermal incompatibility between the two, and optimizing the coping design to minimize tensile loading on the porcelain. Another method of reducing porcelain chipping and fracture is to limit or eliminate the porcelain coverage of zirconia copings and frameworks. Even though patients often demand tooth colored or nonmetallic restorations, they tend to be less concerned with the optimal esthetics of their posterior teeth. This article describes 4 representative clinical situations where efforts were made to minimize or eliminate porcelain coverage on posterior zirconia crowns and a fixed dental prosthesis, while still achieving acceptable, but not optimal, esthetics.

A custom titanium abutment for the anterior single-tooth implant

The anterior single-tooth implant presents many restorative challenges. Several abutments have been developed in pursuit of anesthetic and functional solution. This article describes a technique for a custom abutment. This abutment is copy-milled from titanium in an anatomic form with a countertorque device and provides the flexibility to create an esthetic restoration for the anterior single-tooth implant.

Fabrication of an all-ceramic abutment crown under an existing removable partial denture using CAD/CAM technology

Fabricating a crown beneath an existing removable partial denture is technique sensitive, difficult, and time consuming. A procedure is described using CAD/CAM technology to fabricate an all-ceramic crown under an existing removable partial denture that is simple, esthetic, and convenient for the patient and the clinician.

A procedure for a modified cylindric titanium abutment

In the restoration of a single anterior edentulous space with a dental implant, there are three transmucosal elements that could be used within the Nobel Biocare system: the CeraOne abutment, the Estheticone abutment with a nonrotating gold cylinder, and the CerAdapt abutment. This article describes a procedure to modify the CeraOne cylindric titanium abutment with titanium ceramics to achieve an anatomically shaped transmucosal element that does not show evidence of the metal through thin gingival tissue.

Computed tomography-based, template-guided implant placement and immediate loading: An 8-year clinical report

This report presents an 8-year follow-up of a patient treated with computer-assisted implant planning, template-guided implant placement, and immediate loading. A preoperative diagnostic evaluation resulted in a more predictable implant placement with respect to anatomic structures and the planned prosthesis. Implants were placed in both the maxilla and the mandible, and immediate loading in both arches was provided.

A single appointment protocol to create a partially edentulous CAD/CAM guided surgical template: A clinical report

The traditional technique for creating a CAD/CAM surgical template with a NobelGuide protocol is to fabricate a radiographic template that depicts the planned tooth position first. Multiple appointments are needed for the fabrication of the radiographic template with Cone Beam Computed Tomography (CBCT) before the surgical procedure can start. An alternative technique is described for fabricating a radiographic template at the initial examination appointment and capturing the necessary DICOM data to plan and fabricate a CAD/CAM surgical template in a 1-appointment protocol, thereby saving the patient and clinician time and reducing the need for multiple appointments.

A simplified technique to fabricate a custom milled abutment

aAssociate Clinical Professor, Department of Continuing Education. bAssociate Professor, Department of Clinical Dentistry. cPrivate practice, Pasadena, Calif. (J Prosthet Dent 2007;98:416-417) There are multiple techniques to create custom abutments, some more difficult to use than others for replicating the exact shape and form of the accepted provisional restoration. Techniques include the use of (1) “add-to” abutments, premachined abutments to which gold or porcelain is added, (2) “preparable” abutments, referring to the preparation of abutments that have been manufactured in a bulk material, such as porcelain or titanium, (3) computer-assisted design and computer-assisted manufacturing (CAD-CAM) abutments, using a computer program to custom mill an abutment, and (4) copy milling, using a scanner and computerassisted manufacturing.1,2 With copy milling, an abutment is typically contoured in wax, then scanned to create the abutment. Creating a wax replica of the provisional restoration is time-consuming and may not exactly replicate the transitional contours of the provisional restoration. This article presents a simplified technique to create a custom abutment replicating the exact transitional contours from the provisional restoration in titanium, alumina, or zirconia using a scanner and computer-assisted manufacturing. The abutment can be produced for multiple implant systems such as Nobel Biocare (Nobel Biocare USA, Yorba Lin1 Provisional restoration for maxillary right central incisor fabricated with transitional contours to support transitional tissues. da, Calif ), ITI (Straumann AG, Basel, Switzerland), Astra (Astra Tech AB, Molndal, Sweden), Zimmer (Zimmer Dental, Carlsbad, Calif ), and other external hex implants replicating the hex design of a Branemark implant.