41994_Australasian_Dentist_100_EMAG

CATEGORY LINICAL

of the cusps (Fig. 10). For this reason, it was decided to shorten the buccal cusps in the sense of an onlay preparation and to set them with composite (Fig. 11). A good adhesive technique needs a clean substrate that can be glued to. It is therefore useful to avoid possible negative e ects of irrigation with NaOCl and contamination with root

canal sealer by sandblasting the cavity with Al2O3 10 . After selective fusion etching (Fig. 12) with phosphoric acid and application of a universal adhesive, the channel entrances arecoveredwitha owablebulk- llmaterial that can be introduced in layers up to 4mm thick (Fig. 13). e Tetric PowerFlow used

Fig. 5: Step-by-step restoration of the proximal cavities and cutting edges with Tetric Prime A3,5.

Fig. 9: Condition after root filling and temporary restoration.

Fig. 8: Initial radiological findings tooth 36: deep occlusal caries, apical periodontitis.

Fig. 6: Condition directly postoperatively. Due to the drying out and the associated lightening of the tooth structure during the restoration, the fillings typically appear too dark and too translucent postoperatively.

Fig. 11: The buccal cusps were shortened by approx. 1.5 mm for stability reasons and the cavity was sandblasted with corundum (Al2O3, 50 µm).

Fig. 10: Condition before direct restoration with composite. Root filling is reduced below the level of canal entrances.

All photos © Dr. M. Lenhard

Fig. 7: Finished restoration after rehydration of the tooth structure. The transitions between tooth structure and restoration can only be seen at high magnification and are not clinically relevant.

Fig. 13: 1st layer of Tetric PowerFlow. Due to the unavoidable greater distance to the light guide in the endodontic cavity, it is advisable to double the recommended exposure time during polymerisation.

Fig. 12: Selective fusion etching with phosphoric acid for approx. 15 seconds.

Patient case 2: Endodontic cavity with Tetric PowerFlow and Tetric Prime

e restoration of post-endodontic cavities is usually concerned with restoring the stability and lost volume of the tooth as well as the colour integration of the restoration, since the hard tooth structure usually has to be replaced over a large area. An endodontic access cavity alone reduces the stability of the tooth by only about 5%, while a MOD caviation including the loss of the pulp roof reduces stability by 63% 8,9 . In the latter case, a cusp cover of the tooth is indicated to restore stability. is can be done with indirect or direct restorations. In the present case, the patient presented with very deep caries and apical periodontitis on tooth 36 (Fig. 8). Figure 9 shows the condition after root lling and temporary restoration. e cavity is limited to the occlusal area, but the buccal wall in particular is severely undermined by the removal of the caries, the buccal preparation margin runs through the tips

Fig. 15: Ideally, the occlusal surface is modelled correctly right away.

Fig. 14: Step-by-step layering with Tetric Prime.

Fig. 17: Finished restoration directly postoperatively.

Fig. 16: Finished stratified occlusal surface.

All photos © Dr. M. Lenhard

AUSTRALASIAN DENTIST 83