Dental Asia Jan/Feb 2018

42 USER REPORT DENTAL ASIA JANUARY / FEBRUARY 2018 F or reasons of cost, patients and dentists today often find themselves obliged to use restorative materials for the treatment of large structural, functional and aesthetic defects. This case report demonstrates how an innovative, organically modified ceramic composite with extremely low shrinkage stress and volume contraction can be used to restore teeth while preserving tooth substance. Occlusal functionality is key to the longevity of the restoration. A 71-year-old female patient presented in my practice requiring replacement of insufficient, excessively large composite resin restorations of the lower right Ƥrst and second molars (46 and 47). The natural crown still retained a small amountof residual structure, andthepatient did not wish any further removal of tooth substance. (Fig. 1) For cost reasons, the patient also did not wish any prosthetic treatment, e.g. in the form of ceramic restorations. The patient was recommended a direct complex resin onlay requiring functional and non-functional cusp reduction. With this unconventional approach, it was important that the occlusal design should take into consideration the strengths and weaknesses of both the restorative material and the residual tooth structure. Thepatientwas givena local anaesthetic with 1 cartridgeof 4%articainewith 1:100,000 a caries-free, hard dentine base, three successive checks were performed with a caries detector (Caries Marker, VOCO). by Dr. Clarence Tam Fig. 1: Pre-operative situation showing large restorations andminimal residual tooth structure. Fig. 2: Completed preparation with strongly bevelled margins as an alternative to straight cuspal height reduction. The cusps were at least 3mm thick at their base. The occlusal shaping must be very thorough to minimise the lateral excursion load on the cusps. adrenaline, and the teeth were isolated with a rubber dam prior to removal of the existing restorations. In order to ensure The thickness of the remaining cusps was measured, and found to be 3mm at the base. The margins were strongly bevelled to maximise the amount of the planned restorativematerial withminimal reduction in the cusp region, and thus achieve a large contact surface. No centric contacts or other extensive functional contacts were planned for the cavity areas being treated (Fig. 2). Thepreparationsweremicroair abraded using 27micron aluminium oxide. Then a selective enamel etch technique using 33% orthophosphoric acid was performed followed by bonding with Futurabond U (VOCO). The lingual cusps of tooth 46 were created free-hand using the universal shade Admira Fusion x-tra, a purely ceramic-based bulk- Ƥll composite (Fig. 3). The cusps were widened towards the centro- occlusal aspect progressively in 2mm increments. The key factor here was not applying this bulk- fill material in bulk, and thereby ensuring maximum depth of cure at all times. The benefit of Admira Fusion x-tra is the increased depth of cure which is inherent to this restorative. After curing of the base of the lingual cusps, a sectional matrix system (V3, Triodent) was used.