GAP Australasian-Dentist-Mar Apr 2019

Category 74 AustrAlAsiAn Dentist u nfavourably positioned teeth and/or an asymmetric contour of the soft tissue represent a considerable challenge in the already difficult anterior zone. in order to achieve a natural-looking result, the shape and shade of the restoration have to be suitably matched to the remaining teeth and furthermore the soft tissue needs to be properly conditioned. in many cases, provisional restorations are initially used by the dental team so that the special requirements of the gingiva can be effectively addressed. Case study the 33-year-old patient consulted our practice about having defective dental braces removed after three years of orthodontic treatment. He asked us to treat the carious lesions in his teeth and enhance the appearance of his smile. the first esthetic analysis revealed an unfavourable length-to-width ratio of the anterior teeth (Fig. 1). As a result, the patient wished to have his front teeth lengthened. the upper left canine had to be endodontically treated due to advanced necrosis of the pulp tissue. length-to-width ratio (tooth lengthening) and even out the gingival contour. Manufacturing technique and selection of the materials inorder tominimize the risk of fracture of the ceramic restorations, we decided to use iPs e.max ® Press lithium disilicate ceramic, which demonstrates a high toughness of 470 MPa as well as excellent esthetics. in addition to the monochrome press ingots, this ceramic system includes a polychromatic material (Fig. 2). iPs e.max Press Multi ingots are used to fabricate highly esthetic monolithic restorations that do not need any characterization. they feature a lifelike progression of the shade and translucency between the dentin and incisal areas. the press technique, which involves the use of a full-contour wax-up, offers a quick and uncomplicated method of manufacturing crowns. Moreover, the press technique allows us to reproduce delicate gingival contours with utmost precision. in restorations that are built up in layers, the ceramic sometimes shrinks, making it difficult to accurately replicate the gingival contours of the provisionals. in our opinion, the iPs e.max Press Multi ceramic has two decisive advantages. First of all, its true-to-nature shading imitates that of natural teeth in the cervical and in the incisal region. in contrast to the restorations pressed with monochrome ingots, the polychromatic restorations require less time and effort to fabricate, since they do not have to be customized with layering ceramics in the incisal region. secondly, iPs e.max Press Multi has just the right translucent properties to allow the necessary transmission of light. Clinical treatment First, endodontic treatment was performed and the carious lesions were removed. then the teeth were restored with composite fillings. the front teeth requiring treatment were suitably prepared (Fig. 3) and the provisional crowns were placed (Fig. 4). the right lateral incisor was lengthened. the provisional crowns helped to support the gingival contours and establish a symmetric appearance. Once the desired symmetry of the teeth and gingival tissue was attained, the teeth were prepared for the permanent restorations (Fig. 5) and impressions were taken. Short cut in the digital fast track Exact reproduction of provisionals with IPS e.max Press Multi An article by Dr Hyun-Jun Jung and Kyung-Sik Park, Seoul/South Korea lInICal The shape of an anterior restoration significantly influences the symmetry of the gingival contours. Provisionals that have proved to be suitable both in terms of their function and esthetics allow permanent restorations to be precisely manufactured with the help of digital methods. Figure 1: Preoperative view Figure 2: IPS e.max Press Multi ingot shade A2 Figure 3: Situation after the removal of caries lesions and root canal treatment Figure 4: Provisional composite resin restora- tions for evaluating their function and esthetics Figure 5: Final preparation of the teeth Planning Our plan was to reconstruct the upper anterior teeth. in choosing the most suitable material for the restorations, we had to take into account the fact that the patient enjoyed eating hard nuts. Furthermore, he reported that he had a habit of grinding his teeth at night and clenching his jaws. Consequently, the anterior crowns would have to be not only functional and esthetic, but also very strong and tough. We planned to use six all-ceramic crowns to optimize the CAD/CAM processes in the fabrication of restorations Prior to the removal of the provisional crowns, additional precision impressions were taken. in the laboratory, the data of the preparation models and the provisional crown models was captured using the double scan method. the digital data sets were superimposed on each other. the abutment teeth were separated and the margins and contours were adjusted (Figs 6 to 8). this approach allowed the shape of the provisional crowns to be exactly replicated. We focused on recreating the