Dental Tribune United Kingdom Edition

T he creation of a function- al occlusion is the goal of any prosthetic treat- ment and can be very difficult to achieve in cases of full-mouth rehabilitation, especially in the case of temporo - mandibu- lar joint (TMJ) dysfunction. In these clinical situations, provi- sion al restorations are an excel- lent diagnostic instrument. Aes- thetics, phonetics and function, after evaluation and acceptance by the patient after try-in of the provisional restorations, should be accurately transferred to the final restorations to ensure the same clinical success. The aim of this study is to demonstrate the manner in which individual movement characteristics of a patient’s TMJ can be included in tradi- tional CEREC temporary crown fabrication. New occlusal rela- tions need to be created with respect to the individual char- acteristics, such as mandibular and hinge axis positions, Ben- nett and sagittal angles. The incorporation of occlusal plane formation principles is essential to improve and ease a patient’s adaptation to new occlusal re- lations, as well as to reduce the probability of TMJ dysfunction. However, CEREC software does not enable the inclusion of TMJ para meters. Following, we describe a technique that enables the fab- rication of temporary CEREC restorations with respect to a patient’s TMJ parameters. Step I: Electronic axiography and lateral X-rays Computer analysis of jaw move- ments with electronic axiogra- phy is useful for determining the joint parameters (Fig 1). Using mechanical tracing, axiography enables the collection of data on a patient’s TMJ, such as curve and in clination of the condylar path, mouth opening, Bennett and sagittal angles, mandibular pro trusion and course of the mediotrusive tracks. Lateral X- rays provide data on movement by including the condylar tracks (Figs 2a & b). Step II: Slavicek analysis We used CADIAX (Gamma Den- tal) to analyse the X-rays in de- tail (Fig 3). Here, the distances, spaces and tooth relations are of considerable importance. The vertical dimension and the special position of the occlu- sal plane, the Spee’s curve and the various occlusal tables of the laterals were determined. In the lateral X-ray, we paid partic- ular attention to the occlusion tables of the molars, especially tooth #6. Step III: Partial wax-up A partial wax-up of the individ- ual occlusal surface was mod- elled on the master casts with respect to the TMJ angles and occlusal pattern of sequential functional guidance occlusion with canine dominance (Figs 4 & 5). Step IV: Scanning The partial wax-up was scanned and combined with the virtual images of the teeth stumps and virtual restorations from the CEREC software da- tabase. Thus, we were able to easily control the form, cusp position and inclination of the teeth with respect to individual A new approach Dr Mikhail Antonik, Dr Mikhail Murashov & Dr Natalya Muraviova discuss real-virtual modelling of CEREC temporary crowns May 16-22, 201120 United Kingdom EditionClinical Does it have to be gold? Which one would your patient prefer? Lifelike Dental Ceramics, Butterfly House, Dunton Road, Stewkley, Bucks, LU7 0HZ www.lifelikedental.co.uk Tel: 01525 240 or 07977 501562email: lifelike@btinternet.com Lifelike Dental Laboratory is a small private dental laboratory in Buckinghamshire. We like to think the products we offer are as good as our service, but that’s up to you to decide. We work with you in partnership to ensure that you are able to offer your patient the best solution at a competative price or Gold? by 3d core centres is a new metal free product offered by Lifelike Dental Ceramics For Occlusal reductions as small as 0.7mm Biocompatible Ideal for Bruxers Metal Free Zirconia No Porcelain layers 5 year guarentee card PPosterior Crowns or Bridges 1000 mpa with less chance of fracture £69.00onlyIntroductory Offer - First unit of