CDEN0210

I 43 industry report _ non-prep veneers I cosmeticdentistry 2_2010 orthodontic treatment and successful stabilisation of the dentition. Excess gum was trimmed away with a soft-tissue laser and the gingival contours of the twocentralincisorswereharmonisedwitheachother (Fig. 3). The advantage of laser contouring is that the laser naturally seals the wounds and treatment can becontinuedsoonaftercontouring.Themirrorimage showsthesituationafteroneweekwithapalatalview of the anterior teeth (Fig. 4). _Thin and yet stable At the next stage, the dental technician in charge determined the final tooth shade with the help of ashadeguideandshadesamples,takingintoaccount the initial tooth shade, which plays a major role par- ticularly in very thin translucent restorations. An im- pressionwastakentocreateamodelwithdetachable segments. A wax-up was designed on the model to plan and determine the position of the incisal edges. Intheprocess,particularcarewastakentoextendthe incisal edges only minimally. Otherwise, the com- pletedrestoration insitu wouldhavegivenanoptical impression of being too long. Please note that the dental technician should applynomorethantwothincoatingsofdiespacerto thedies.Thespacershouldbeappliedonlyupto1mm fromthepreparationmargininordertoavoidhollow restoration margins in the oral cavity. Thin veneers, as presented in this case, are fabri- catedbycreatingafullyanatomicalwax-up,whichis pressedandthencharacterisedwithstains.IPSe.max Press (Ivoclar Vivadent) is ideally suited for this pur- pose. This material is composed of lithium disilicate glass-ceramicandis2.5to3timesstrongerthanother glass-ceramicmaterials.Havingaflexuralstrengthof almost 400 MPa, IPS e.max Press offers exceptional stability (Fig. 5). These characteristics convey suffi- cient strength to veneers, inlays, crowns and similar restorations to withstand comparatively high loads. Furthermore, restorations made of IPS e.max Press look impressively beautiful. The product range in- cludes special press ingots, which offer an increased level of opacity for cases in which the underlying tooth structure is discoloured. These ingots effec- tively mask dark areas and provide a natural-looking aesthetic result, even if the teeth are discoloured. _Precisely to prescription Inthecasepresentedhere,teeth#13to23werere- storedwithnon-prepveneers.Thehighlytranslucent IPS e.max Press HT ingots are particularly suited for this type of minimally invasive thin restoration. First, the dental technician creates an anatomical wax-up of the veneer using organic wax that burns out with- out leaving residue. In this respect, the final occlusal relief must be taken into consideration as early as during the wax-up. The subsequent application of stain and glaze materials results in a slight increase in the vertical dimensions of the restorations. The technician should strictly adhere to the mini- mum thicknesses stipulated for the relevant lithium disilicate glass-ceramic. According to the manufac- turer’sdirections,theminimumthicknessofIPSe.max Press is 0.3 mm in the cervical and labial area, and 0.4 mm at the incisal edge (Fig. 6). Thewaxmarginsaretaperedtowardstheend.The transitions between restoration and tooth structure shouldbecontouredparticularlycarefully.Inthisway, theneedforlatercorrectionscanbepre-empted.Itis wellknownthatinexperiencedtechniciansoftenfind itdifficulttocreatesuchathinwax-upandthustend to create thicker wax-ups. However, it is unnecessary to over-contour the margins as a precaution, as the technician may then have to rework the restorations after they have been pressed and divested. This takes time. Thus, it is best to contour as suggested by the manufacturer right from the start. _Everything under control TheveneersarepressedinaProgramatEP5000ce- ramicpressfurnaceat920°C.Uponcompletionofthe press cycle, they are carefully divested—adjustments arekepttoaminimum.Thespruesareseparatedwith Fig. 5_Veneers are best contoured in a fully anatomical shape and pressed. Fig. 6_Thin veneers should have a thickness of at least 0.3 mm in the cervical area and 0.4 mm in the incisal. Fig. 5 Fig. 6

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