cosmetic dentistry_ beauty & science

12 I I special _ composites _New shading approach: the natural layering concept To achieve perfect direct restorations has been for long and hypothetical aim due to the imperfect optical properties of many composite resins systems. So far, the over-simplification (mono-incremental) as well as over-complexity (multi-incremental) of shading systems has tremendously limited the benefit of direct com- posite restorations. Even today, the complexity of some systems is often associated to shading concepts mimicking ceramic systems (which are applied in totally different layer thicknesses) or the influence of over-meticulous clinicians who compensated deficient composite optical prop- erties with intricate layering concepts. The use of the natural tooth as a model and the identifi- cation of respective dentine and enamel optical characteristics (tristimulus L*a*b* colour meas- urements and contrast ratio) has then been a landmark in developing better direct tooth coloured materials.4, 7–8 The ‘natural layering concept’ is then a simple and effective approach to creating highly aesthetic direct restorations which has become a reference in the field of composite restorations.9–12_ _References 1. Macedo G, Raj V, Ritter AV. Longevity of anterior composite restorations. J Esthet Restor Dent 2006;18:310-311. 2. Peumans M, Van Meerbeek B, Lambrechts P, Vanherle G. The 5-year clinical performance of direct composite additions to correct tooth form andposition.II.Marginalqualities.ClinOralInvestig. 1997;1:19-26. 3. Peumans M, Van Meerbeek B, Lambrechts P, Vanherle G. The 5-year clinical performance of direct composite additions to correct tooth form and position. I. Esthetic qualities. Clin Oral Investig. 1997;1:12-8. 4. Dietschi D, Ardu S, Krejci I. A new shading concept based on natural tooth color applied to direct composite restorations. Quintessence Int. 2006; 37:91-102. 5. Magne P, So WS. Optical integration of inciso- proximal restorations using the natural layering concept. Quintessence Int. 2008;39:633-43 6. Dietschi D. Optimizing smile composition and esthetics with resin composites and other con- servative esthetic procedures. Eur J Esthet Dent. 2008;3:14-29. 7. Cook WD, McAree DC. Optical properties of es- thetic restorative materials and natural dentition. J Biomat Mat Res 1985;19:469-488. 8. Dietschi D, Ardu S, Krejci I. Exploring the layering concepts for anterior teeth. In Roulet JF and Degrange M, Editors: Adhesion – The silent revolu- tion in Dentistry. Berlin, Quintessence Publishing, 2000:235-251. 9. Ubassy G. Shape and color: the key to successful ceramic restorations. Quintessenz Verlag, Berlin; 1993. 10. DietschiD.Free-handcompositeresinrestorations: a key to anterior aesthetics. Pract Periodont & Aesthetic Dent 1995;7:15-25. 11. Dietschi D. Free-hand bonding in esthetic treat- ment of anterior teeth: creating the illusion. J Esthet Dent 1997;9:156-164. 12. Dietschi D. Layering concepts in anterior composite restorations. J Adhesive Dent 2001;3:71-80. cosmeticdentistry 4_2013 So far, the over-simplification (mono-incremental) as well as over-complexity (multi-incremental) of shading systems has tremendously limited the benefit of direct composite restorations. Didier Dietschi,DMD,PhD, Privat-Docent.Senior lecturer, Department of Cariology & Endodontics,School of Dentistry,University of Geneva, Switzerland.Adjunct Professor, Department of Comprehensive Care,CaseWestern University, Cleveland,Ohio.Private practice & Education Center –The Geneva Smile Center,Switzerland. The Geneva Smile Center 2 Quai GustaveAdor 1207 Geneva Switzerland cosmeticdentistry _about the author