David G. Wildgoose

The laboratory construction and teaching of ceramic veneers: a survey

OBJECTIVE The aim of this study was to identify current trends in the methods and materials used during teaching and construction of ceramic laminate veneers within the laboratory. METHOD A questionnaire was designed to determine the most popular laboratory techniques and materials used during the teaching and construction of ceramic veneers at a number of university dental schools and teaching hospitals in the United Kingdom, Ireland and Hong Kong, and to identify the role of technical staff. RESULTS The responses showed that approximately 63% of teaching hospitals and 53% of dental schools were involved with either the construction or teaching of laboratory techniques for ceramic veneers. Of two substrate materials identified, it was clear that the use of phosphate refractory models was preferred to the platinum foil technique. A wide range of refractory and ceramic materials was reported, some of which were supplied as combined system products. However, a larger number were ceramics and refractory materials acquired from independent manufacturers and therefore not necessarily matched. CONCLUSION Although clear information was provided by the manufacturers to identify the thermal expansion coefficient of their dental ceramic, this is not the case for most of the phosphate refractory materials. As a result, intermixing of individual ceramic and refractory products was commonplace with some combinations having different thermal expansion coefficients. To avoid this thermal mismatch, clear information relating to both products needs to be provided by the manufacturers.

Correction of a mandibular asymmetry using a custom-made titanium onlay

The diagnosis and treatment of facial deformities, including mandibular asymmetries, can pose a significant clinical problem. The limitations, accuracy and predictability of treatment options available and the expectations of the patient can further compound this. In this article we present a case of facial asymmetry secondary to mandibular angle deficiency corrected by the manufacture and placement of a custom-made titanium onlay. Although alternative methods were potentially available to correct this deformity, patient factors including occlusion, dental/skeletal relationship and chin position limited our options. Furthermore, construction of the custom-made titanium onlay involved the development of a computer-generated 3D virtual model and computer-aided design and computer-aided manufacture (CAD-CAM) of the inlay. This report demonstrates that this technique can be used successfully to address certain cases of facial asymmetry.