Australasian Dentist Magazine May June 2021

Category Australasian Dentist 65 such as the replacement of a buccal wall or the reconstruction of an occlusal surface, may the use of a universal composite be again advantageous. The data situation for bulk fill composites looks very good. There is currently no indication that bulk fill composites perform worse in clinical applications than conventional composites. Clinical studies comparing bulk fill and conventional composites have not found any differences between the two (van Dijken und Pallesen 2016, Yazici et al. 2017, Heck et al, 2018, Tardem et al 2019). Bulk fill composites shorten the layering process. This is only one part of the treatment protocol; all the other parts (anaesthetisation, preparation, etc) remain unchanged. The possibilities for saving time are therefore limited, but the part in which the restoration is vulnerable to contamination is simplified. The simplification made possible by the bulk fill technique brings a welcome advantage. Case 1: Class III and IV restored with Tetric Prime The patient presented with a request to have the incisal edges of teeth 11 and 21 straightened and to replace the existing discoloured fillings on themesial and distal aspects of these teeth (Fig. 1). The patient’s history revealed that the fractures of the incisal edges were not related to function but were primarily caused by a habit. Fig. 2 shows the teeth after removal of the existing fillings. Following selective enamel etching with phosphoric acid (Fig. 3) and application of a universal adhesive (Adhese Universal, Fig. 4), the anterior teeth were restored using Tetric Prime (Figs 5-7). These monochromatic restorations were fabricated using only one shade (A3.5 in this case). The Tetric Prime shades feature a translucency of 11.5%. This represents a good compromise between the translucency of the dentin and enamel, allowing most restorations to be placed without layers of various shades. If a more opaque (i.e. less translucent) layer in the anterior region or masking of discoloured dentin is required, the A2 and A3.5 shades are offered in a dentin version that features a significantly reduced translucency of only 7.5%. I find the new Tetric Prime very pleasant to work with, as it is soft and easy to contour. Technically, a universal composite such as the Tetric Prime presented here is sufficient to meet the requirements of everyday restorative work with just one composite. Since the introduction of bulk fill composites, however, it has become possible to simplify certain applications without lowering the quality of the work. A variant route is shown in the second case below: a universal composite is applied in combination with a flowable bulk fill. The latter is intended as volume replacement and as such reduces the number of increments required. Case 2: Endodontic cavity restored with Tetric PowerFlow and Tetric Prime Generally, the aim of a post-endodontic treatment is to restore the tooth to its prior stability and volume and to match the shade of the restoration to the surrounding tooth structure, as these restorations usually require the replacement of large areas of natural tooth structure. An endodontic access cavity alone reduces the stability of the tooth by only approx. 5%, while a MOD cavity, with the pulp roof removed, reduces the stability by 63% (Reeh et al. 1989, Howe and McKendry 1990). In the latter case, cusp coverage is indicated to restore the stability of the tooth. This can be achieved with a direct or indirect restoration. In the case shown here, the patient presented with very deep caries and apical periodontitis on tooth 36 (Fig. 8). Figure 9 shows the tooth after endodontic treatment and temporisation. The cavity is limited to the occlusal area. However, the buccal wall has become severely undermined by the removal of the caries; the buccal preparation margin runs through the cusp tips (Fig. 10). For this reason, I decided to reduce the buccal cusp tips, similar to an onlay preparation, and to encase them with composite (Fig. 11). An effective adhesive technique requires a clean substrate for bonding. It is therefore advisable to sandblast the cavity with Al2O3 to avoid any possible adverse effects due to the NaOCl irrigant and contamination with root canal sealer (Alshaikh et al. 2018). After selective enamel etching (Fig. 12) with phosphoric acid and application of a universal adhesive, the canal openings clinical Fig. 8 Radiological preoperative situation of tooth 36: deep caries emanating from the occlusal surface and apical periodontitis. Fig. 10 Situation prior to the direct restoration with composite. The root canal filling is reduced to be below the level of the root canal openings. Fig. 12 Selective etching of the enamel with phosphoric acid etching for approx. 15 sec. Fig. 9 Situation after endodontic treatment and temporisation. Fig. 11 The buccal cusps are reduced by approx. 1.5 mm to ensure adequate stability and the cavity is sandblasted (Al2O3, 50 µm). Fig. 13 First increment of Tetric PowerFlow: An increase in the distance between the material and light guide is unavoidable in endodontic cavities. It is therefore recommended to double the recommended exposure time.