GAP Australasian-Dentist-Mar Apr 2019

Category 78 AustrAlAsiAn Dentist t his report describes the restorative treatment with a lithium disilicate glass-ceramic – a material that features excellent long-term clinical properties. A CAD/CAM manufacturing process was chosen to enhance the efficiency of the treatment. After a try-in in the blue (non- crystallized) state, the restoration was finalized and customized by hand in the laboratory to provide a final result with excellent esthetic properties. Questions to explore 1. How can CAD/CAM technologies be combined with manual skills to achieve outstanding restorative results? 2. How to select suitable materials to mask discoloured substrates and take advantage of an intelligent app (snA) to select an appropriate shade and translucency? 3. How can severely discoloured tooth preparations be masked and their shade matched to the shade of the neighbouring teeth? Preoperative situation A 29-year-old female patient consulted the practice with the wish to have a natural beautiful smile. she was dissatisfied with her upper anterior restorations and the appearance of the surrounding soft tissue. she wished for a functional and esthetic solution (Fig. 1). Photographs of the oral situationweretakenduringmedicalhistory- taking and the patient’s expectations were discussed. the intraoral examination revealed severe discolouration, devitalized teeth and poor esthetics. in addition to an inappropriate shade, the upper anterior crowns and veneerswere out of proportion, causing an inharmonious smile line (Fig. 2). An X-ray confirmed the suspicion that the endodontic fillings on the two central incisors were defective. the lateral incisors had been repaired with large composite restorations. Due to the inadequate contouring of the underlying composite, the patient showed clear signs of periodontitis in the area of all four anterior teeth. An impression of the situation was taken. the study model provided a physical reference that was used to mark the relevant lines and planes, align the longitudinal axes, adjust the lengths and implement cosmetic optimizations in line with the digital design concept (Fig. 3). A diagnostic wax-up was created. then, a silicone key was produced from the wax- up for the fabrication of the temporaries. the silicone key also served as a guide in the preparation of the teeth. Preliminary treatment the existing restorations on the upper anterior teeth were removed. teeth ur2 to ul2 were prepared with a rounded shoulder of 1 to 1.2 mm and equigingival margins, according to the preparation guidelines for all-ceramic crowns. the depth varied slightly due to the shade of the preparation and degree of discolouration. the dark discolouration on the dentin of the right central incisor required a deeper preparation in order to be able to mask the shade of the remaining tooth structure (Fig. 4). teeth ul3 and ur3 were prepared for veneer placement with an equigingival chamfer, 0.5-mm buccal reduction and 1-mm incisal reduction (Fig. 5). An impression of the resulting situation was taken using A-silicone and then direct temporaries were created with the help of the silicone key (Fig. 6). the periodontal situation was monitored over the following two weeks. Gingival healing was uneventful. the temporary restorations allowed the final result to be visualized. At this stage, intraoral adjustments could be made to achieve a harmonious symbiosis between the lips, smile and face. A skilful combination of CAD/CAM and manual work Modern materials and manual skills skilfully combined to achieve long-lasting esthetic restorations A report by Aiham Farah, Dubai and Anas Aloum, Abu Dhabi/both United Arab Emirates The aim of a restorative treatment is to re-establish the esthetic properties of the tooth structure to ensure that it blends in with the shade and vitality of the natural surroundings whilst using the least invasive methods possible. Severe discolourations often aggravate the initial preoperative situation in addition to misalignments, damaged teeth and/or existing restorations. Extensive reconstructions require the combination of modern materials and technologies with manual skills. Outstanding results can be achieved by carefully selecting suitable materials, masking discoloured preparations and implementing an optimum preparation design. The success can be seen in restorations that remain stable and intact over many years. Figure 1: Initial appearance of the smile Figure 3: Smile design with newly proportioned length and width of the incisors in line with the digital smile design concept Figure 2: Preoperative oral situation with periodontitis, discoloured restorations and devitalized teeth. Inadequate esthetic characteristics of the individual teeth and inharmonious smile line lInICal