Retrospective Study of 18 Titanium Alloy Crowns Produced by Computer-Aided Design and Manufacturing in Dogs.

Computer-aided design (CAD) and computer-aided manufacturing (CAM) technology is routinely used in various fields of human dentistry, particularly prosthodontics. Reverse engineering and additive manufacturing allow the technician to create an easier, faster and more accurate restoration, with a natural design and adequate strength. Eighteen titanium alloy full crowns were produced for canine teeth of 7 working dogs using CAD/CAM technology (3D BioCare, Nobel Biocare). Reasons for crown therapy included abrasion, enamel infraction, and crown fracture. Crown preparation was routinely performed, and impressions were delivered to the laboratory where digital impressions were performed with a lab scanner. Using 3D dental design software, the metal crown was designed and sent for manufacture. Each prosthodontic crown was then carved from a solid titanium alloy block to obtain the final crown. All prosthodontic crowns were an adequate fit, and cementation was routinely performed. Crowns were lost from 2 canine teeth during the dogs' normal working activity, in one case, for 2 times. In all cases, replicas were requested. In the first case, the second cementation was successful. In the second case, the second crown was again lost and only the third cementation was successful. Follow up of all cases range from 12 to 62 months. Mean survival time for the crowns was 58.0 months. Here, CAD/CAM technology is shown to be a useful tool for manufacturing accurate prosthodontic crowns for veterinary patients. Moreover, CAD/CAM enables the production of prosthodontic crown replicas in a very short time and at relatively low cost compared to traditional methods, consequently eliminating the need for at least one anesthetic procedure in the incidence of crown cementation failure.

Quantitative Comparison of Mathematical Models to Measure Surface Area of Canine Teeth Prepared to Receive Full Veneer Crowns in Dogs.

OBJECTIVE: This study was performed in order to determine if mathematical modeling of the canine teeth in dogs could be utilized to provide an accurate and reliable estimation of crown surface area that could be used in both a research and a clinical setting. MATERIALS AND METHODS: Actual surface area (aSA) calculations for 32 stone dies of clinical crown preparations were acquired utilizing a tridimensional (3D) laser scanner and 3D computer-aided design and manufacturing (CAD/CAM) software applications. These calculations were used as a control. Seventeen unique mathematical models from eight geometric shapes were used to calculate estimated surface area (eSA) of each stone die. Linear association and agreement between eSA and aSA calculations were assessed with multiple statistical methods. RESULTS: All methods of eSA showed a significant linear association with aSA. Five of the mathematical models [right elliptical frustum (H3), right elliptical cone (G3), right pyramidal cone (A3), right circular frustum (F2), and right circular cone (E1)] were superior to the other 12 models. CONCLUSION: The H3 mathematical model based on the right elliptical frustum provided the most accurate estimate of crown surface area of dog teeth. However, H3 requires the use of laser scans and a 3D CAD software program. As a result, this model would be recommended for research applications. The E1 mathematical model was similar in accuracy to H3 and, given it requires only two measurements and a comparatively simple equation for calculation, this method would be recommended for clinical chair-side use.

Maxillary anterior all ceramic restoration using digital impression and CAD/CAM / 대한치과보철학회지

The digital impression technique has been developed for more precise restorations and convenient procedures in prosthodontic treatment compared to the conventional impression technique. Along with the utilization of CAD/CAM, the introduction of digital impression technique actualizes the digitalization of dental treatments. This case is to compare two different prostheses introducing each procedure in detail; one from CAD/CAM after taking digital impression and the other from the conventional technique. A 22-year-old female visited the clinic with the chief complaint of correction of discoloration and shape on maxillary right central incisor. Due to the trauma 8 years ago, the tooth was endodontically treated with post and resin core. The treatment was planned and the procedures were conducted under the patient's consent to treat the tooth with all ceramic crowns in two different ways for comparison. In conclusion, both prostheses presented clinically acceptable results with comparing the internal fitness of two all ceramic crowns. The prosthesis from digital impression, however, showed more errors in respect of internal fitness.