CAD0110

12 I I case report _ prosthodontic rehabilitation _Introduction _Prudent clinical judgement and careful consid- eration of the risks and benefits of various treatment options are essential for the treatment planning and long-termsuccessofprosthodontictreatment.1 Ithas been established that loss of the vertical dimension of occlusion (VDO) may pose significant clinical diffi- culties in prosthodontic treatment.2,3 Yet, the re-es- tablishmentandmaintenanceofanewVDOisseldom taughtinundergraduatedentalcurricula. VDO is defined as the vertical measurement of the facebetweentwoselectedpointssuperiorandinferior to the oral cavity when the occluding members are in contact.4 Various methods have been proposed for the assessment and re-establishment of the VDO.3 The difference between the vertical measurement of physiological rest position, which should have a higher value than the VDO, and the VDO is referred to as the inter-occlusal rest space,4 which is essential for normal patient function. As teeth are worn down, the alveolar bone may undergo an adaptive process that may compensate for the loss of tooth structure.5 The VDO should be carefully assessed before the ini- tiationofrestorativeprocedures. Traditional porcelain-fused-to-metal anterior crown restorations require the placement of labial crown margins below the free gingival margin, in or- der to mask the hue and value transition between the root surface and porcelain-fused-to-metal restora- tion. However, intra-crevicular placement of crown margins is technique-sensitive and related to adverse periodontal tissue response.6–9 From a periodontal pointofview,preparationmarginsarebestkeptaway fromthefreegingivalmargin.8,9 The dentition, masticatory muscles and temporo- mandibular joints form a Class 3 lever system. In such CAD/CAM 1_2010 Management of a full mouth prosthodontic rehabilitation Authors_ Dr Ansgar C. Cheng, Dr Helena Lee, Dr Neo Tee-Khin & Ben Lim, Singapore Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 1_Pre-treatment frontal view showing attrition, erosion, discolouration and compromised aesthetics. Fig. 2_Pre-treatment maxillary occlusal view showing general loss of enamel on the occlusal surfaces. Fig. 3_Pre-treatment mandibular occlusal view revealing loss of occlusal tooth structure and differential erosion loss of dentine. Fig. 4_Panoramic radiograph showing adequate alveolar support. Fig. 5_Anterior view of the full maxillary and mandibular diagnostic wax-up. Fig. 6_Completed maxillary anterior teeth preparations for full coverage restorations. Note the equi-gingival preparation margins.