GAP Australasian-Dentist-Mar Apr 2019

Category 88 AustrAlAsiAn Dentist Jason Smithson By Jason Smithson Case report with Spectra ST effects lInICal A 72-year old partially dentate female patient attended for reconstruction of her upper arch. the upper right molar tooth was deemed unrestorable andwas extracted as part of the overall plan. the remaining right lateral incisor and central incisors (1.2, 1.1 and 2.1) had existing failing direct resin restorations and showed moderate wear. Due to budget constraints these teeth were restored with direct resin (Dentsply spectra st effects) followed by a chrome-cobalt removable partial denture. Figure 1 Figure 4 The teeth were isolated with latex free rubber dam and the sulcus inverted with floss ties: the existing restorations were removed with a diamond burr in a 1.5 speed increasing electric handpiece. Figure 6 cont. A PVS stent was fabricated from a diagnostic wax up and used to guide the placement of the palatal layer: Dentsply Spectra ST D3. This opaque effect shade blocks light transmission and helps to disguise the transition between tooth structure and restoration. In addition, the D3 reduces the potential for loss of value (or “greying”) of the restoration. Figure 2 The patient pretreatment showing remaining 3 incisors with existing failing restorations and moderate TSL (Tooth Surface Loss). Figure 5 Caries was excavated at low speed with a steel rosehead burr. Particle abrasion was carried out with 29-micron alumina at 2-3 bar to remove biofilm and aprismatic enamel. Figure 7 The completed D3 layer: in the hands of the author this is finished to full incisal length, although thinned incisally to improve light transmission; the layer is approximately half the bucco-lingual thickness of the final restoration. Figure 3 The patient pretreatment showing remaining 3 incisors with existing failing restorations and moderate TSL (Tooth Surface Loss). Figure 6 The teeth were etched with 37% phosphoric acid (Total Etch protocol) for 30s on enamel and 15s on dentine and Prime and Bond Active (Dentsply Sirona) bonding agent applied and light-cured for 20s after solvent. Figure 8 The D3 layer is overlaid on the facial with the A3.5 Cloud Shade (DS/ Spectra ST): this mass is less opaque; the increased translucency adding a perception of “depth” to the restoration. This layer is at full contour, however the incisal 2-3 mm is finished around 0.2-0.3 mm under contour to allow addition of incisal effects. The contacts are not closed at this point. BEFORE (left) AFTER (below)