CATEGORY AUSTRALASIAN DENTIST75 depth of cure made it well suited to this indication, supporting an efficient layering strategy without the need for multiple shade selections or numerous thin increments. Materials used in Case 1 u Tetric plus Flow, Shade A2 plus (cavity liner) u Tetric plus Fill, Shade Bleach plus (proximal marginal ridge) u Tetric plus Fill, Shade A2 plus (occlusal body and anatomy) Devices used: Bluephase PowerCure curing light, OptraGloss polishing system Curing protocol: 3-second exposures (posterior) per increment PROCEDURE FOR CASE 1 Isolation and cavity preparation The operative field was isolated with a rubber dam and secured with a metal clamp. The defective composite restoration was removed in its entirety, and the mesial marginal ridge was opened to gain access to the proximal carious lesion. Following complete caries excavation, the cavity presented as a well-defined compound preparation involving the occlusal surface and mesio-proximal box (Fig. 2). Clean enamel margins were confirmed around the full circumference of the cavity. Matrix system, adhesive protocol and curing A sectional matrix system, comprising a metal band, ring retainer, and wooden wedge, was placed to define the mesioproximal wall and establish the gingival seal prior to composite placement. Orthophosphoric acid was applied to the prepared enamel and dentine surfaces according to the total-etch adhesive protocol. Following rinsing and gentle airdrying, the bonding agent was applied, dispersed, and cured with the Bluephase PowerCure (Ivoclar) (Figs. 3-4). Composite layering The layering strategy centred around the 4mm depth of cure that Tetric plus provides. It was the key enabler of this approach. In a cavity of the dimensions presented here, a conventional composite that requires 2mm increments would need several separate placements and multiple curing cycles. With Tetric plus, the same volume can be completed in fewer layers, each cured in 3 seconds with the Bluephase PowerCure, reducing both chair time and the number of steps at which errors could potentially occur. First, Tetric plus Flow A2 plus was injected into the deepest aspect of the cavity floor (Fig. 5), forming a thin liner layer that adapted intimately to the cavity contours and ensured void-free coverage of the pulpal floor and the base of the axial wall. This increment was cured with a 3-second exposure using the Bluephase PowerCure. Why was Tetric plus Flow chosen here? – Thixotropy and rapid 3-second curing Tetric plus Flow is thixotropic: applied gently in small amounts, it remains stable and does not run, which is useful in confined anterior Class III or V preparations. Under pressure, the same property allows it to flow readily into posterior cavity floors and adapt closely to the preparation.1 Its dual photoinitiator system, combining camphorquinone with Ivocerin, enables efficient 3-second curing with Bluephase PowerCure and reliable photoactivation through increments of up to 4mm.2 The material is designed for energy reciprocity, so the curing energy delivered in 3 seconds at high intensity can achieve polymerisation performance comparable to longer, lower-intensity protocols, supporting efficient posterior bulk-fill workflows without compromising curing reliability or mechanical performance.3 Safety is supported by in vitro data showing comparable intrapulpal temperature increases for the 3-second and 10-second modes, remaining below the commonly cited 5.5°C threshold for irreversible pulpal injury.4 However, the 3-second protocol should be used only for posterior Tetric plus restorations in permanent teeth, cured from the occlusal surface, with adequate intervals between repeated exposures. Tetric plus Fill in shade Bleach plus was then applied to reconstruct the mesio-proximal marginal ridge in a single increment. The Bleach plus shade was selected for this layer because its higher value and carefully balanced masking capacity help to establish a bright, naturallooking proximal wall that integrates well with the surrounding enamel at the contact area. This increment was also cured at 3 seconds. The occlusal volume was subsequently filled with Tetric plus Fill A2 plus, a shade that integrates predictably with the warm natural tooth colour in this patient’s posterior dentition. Why was Tetric Plus Fill chosen here? – The translucency change One clinically important property of Tetric plus is its translucency shift during polymerisation. Before curing, Tetric Plus is highly translucent, approximately 36% for Fill and 38% for Flow, because the refractive indices of the monomer and filler are closely matched. This allows CLINICAL Fig. 1: Initial clinical situation. Tooth 16 presents with a defective occlusal composite restoration and dark discolouration at the mesial marginal ridge, a finding indicative of secondary caries. Diagnosis was confirmed by bitewing radiograph. Fig. 3: Caries excavation is complete. The sectional matrix, ring retainer, and wooden wedge are in position. Orthophosphoric acid gel is visible across the prepared cavity surfaces prior to rinsing Fig. 5: Tetric plus Flow A2 has been applied as a liner to the cavity floor and deepest aspects of the preparation. The thin, glossy layer is visible adapting to the cavity walls. The remaining volume, including the proximal box and occlusal anatomy, is open for the sculptable increments. Fig. 2: Following rubber dam placement, the defective restoration has been removed and the mesial marginal ridge opened. Residual carious dentine with brown discolouration is visible in the mesial and central aspects of the preparation, confirming the extent of the lesion. Fig. 4: The bonding agent has been applied and the Bluephase PowerCure is delivering a 3-second curing exposure through the matrix system. The broad-spectrum output of the PowerCure unit is optimised for the Ivocerin photoinitiator in Tetric plus.
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