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| case report direct composite restorations Fig. 9: Immediate post-operative situation before application of hypomineralisation details on triangular ridges. Fig. 10: Situation after application of hypomineralisation details to the triangular ridges using FinalTouch white. Fig. 9 Fig. 10 are not willing to invest a lot of money in their teeth. In view of this, it is essential to understand the physical properties of direct and indirect restor- ative materials in order to design the appropriate restoration. Composite resins have high compressive strength, but only low tensile strength and flexibility. The compressive strength of enamel is 384 MPa and that of dentine is 297 MPa. In contrast, the flexural strength of dentine is 165.6 MPa. The compressive strength of Admira Fusion x-tra is 307 MPa, while its flex- ural strength is 132 MPa —acceptable values when compared to natural tooth substance. The major advantage of Admira Fusion derives from its material compo- sition, as it contains no conventional methacrylate monomers, and therefore allows a more biocom- patible restoration (essentially a purely ceramic- based composite compatible with all bonding sys- tems). At the same time, the composition gives an extremely low volumetric shrinkage (1.25 per cent), the lowest of any product currently on the market. The ability to maintain an optimal marginal seal is also critical in the Class II restorations shown, espe- cially in the case of dentine-bound restoration mar- gins below the cementoenamel junction (CEJ). Arora et al investigated the role of flowable com- posites with regard to the marginal integrity of sub- CEJ Class II restorations and found a significant re- duction in microleakage when a flowable composite liner was used instead of a purely packable compos- ite resin.1 The premise of this study is that the first point of failure of Class II restorations is generally at the restoration margin, in the region of the proximal box floor, especially when located subgingivally. Thus, both volumetric shrinkage and shrinkage stress are two additional key factors with regard to high marginal precision and integrity. The extremely low shrinkage stress (3.71 MPa) of this bulk-fill material, in combination with a high depth of cure, ensures maximum marginal integrity, especially if used in small increments like a conven- tional composite. In terms of avoiding gingival irri- tation, biocompatibility plays an important role, and ceramic-based composites are less conducive to the formation of biofilm than resin composites. The remarkable chameleon effect of this material, combined with optimal working properties, makes it the go-to choice for 90 per cent of posterior res- torations in my practice. When combined with the easy-to-apply customisation shades in the Final- Touch range, it enables me to increase enormously the efficiency, aesthetics, predictability and mar- ginal integrity, essentially with just a single smart material._ Reference 1. Arora, R., Kapur, R., Sibal, N., Juneja, S. Evaluation of Micro- leakage in Class II Cavities using Packable Composite Resto- rations with and without use of Liners. Int J Clin Pediatr Dent. 2012;5(3):178–184. contact Dr Clarence Tam heads a practice in Auckland, New Zealand, which specialises in cosmetic and restorative dentistry. Born in Canada, she graduated from the University of Western Ontario and completed her residency at the University of Toronto. She is the chairperson of the New Zealand Academy of Cosmetic Dentistry (NZACD) and Certified Member of the American Academy of Cosmetic Dentistry (AACD). clarence.tam@gmail.com www.clarencetam.co.nz Fig. 11 Fig. 11: Final post-operative situation showing light centric point contacts, free of functional lateral excursive interferences, and with full aesthetic integration. 24 cosmeticdentistry 1 2017