Obtaining Dental Impressions
Recent reports5 state concerns about the growing shortage of traditionally trained dental laboratory technicians worldwide. This counters the increasing numbers of dental school graduates and the rise in retirement age of practicing dentists.6,7 It seems that there will be fewer dental technicians prepared to service dentists who use elastomeric impressions and require solid models, dies, waxing, casting, and various stages of metal work. One answer invites dentists to purchase and learn the use of intraoral impression scanners and get into the digital workflow. Clinicians can be confident in the accuracy of CAD/CAM based on intraoral scanner data as described in recent publications.8,9
There are many intraoral impression scanners in the dental marketplace today; a recent publication lists a total of eight, all with different requirements, specifications, and warranties.10 The CS 3500 (Carestream Dental, www.carestreamdental.com) is a compact intraoral scanner that can take 2D and 3D color images. It is portable with a USB cable that can be plugged into any workstation. It has an ergonomic shape, a slim scanner head and requires no powder. The CS 3500 captures still images, which are stitched together by the software until a complete dimensional impression is made. A light guidance system aids in the data capture during the image acquisition process. The speed of image capture can be adjusted by the operator. The software generates a stereolithic (STL) file, which can be electronically sent to the dental laboratory for uploading and restorative fabrication. Solid models and dies, waxing, and casting procedures become optional in this process.
The treatment plan for this patient included a custom abutment (zirconia body with titanium metal screw insert), and splinted final crowns for the central incisors.11 The patient was not averse to splinting and was not comfortable with the possibility of future incisal edge discrepancies or open tooth contacts resulting from migration of the natural teeth adjacent to the dental implant, as have been reported.12,13
At the first try-in of the new work, the custom abutment was evaluated and overall healing assessed. The interdental papilla between the right lateral incisor and the new dental implant was diminished by the crown exposure surgery, as previously described. The patient did notice this “dark space” between the right lateral incisor and the pontic of the provisional prosthesis, so it was decided to augment the contour of the mesio-labial surface of the maxillary right lateral incisor with direct composite resin (Point4™, Kerr Dental, www.kerrdental.com) to facilitate space closure of the gingival embrasure between the natural lateral incisor and the dental implant restoration (Figure 10). The final restoration would be designed to follow the recommended guidelines for the distance from the bottom of the contact point to the bony crest for both papillae—mesial and distal to the implant.14
Although a long-term postoperative photograph is not yet available, it seems that the interdental papillae between the maxillary right lateral and central incisors, and between the two central incisors are filling in. In this case, the patient had the option of choosing shade matching with the maxillary lateral incisors or with the four mandibular incisors. He chose the latter.
The patient seems well satisfied with the final outcome and we anticipate a favorable long-term prognosis. His low lip line smile display continues to forgive most prosthetic dental shortcomings (Figure 14).
The author wishes to thank Mr. John Aguirre, Carestream Dental laboratory representative, for his technical advice and for preparation of the image shown in Figure 9.
The author has no relevant financial relationships to disclose.
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About the Author
Joseph R. Greenberg, DMD, FAGD
Clinical Professor, Restorative Dentistry
The Kornberg School of Dentistry at Temple University
Clinical Professor of Periodontics
The University of Pennsylvania School of Dental Medicine