Shading concepts and layering techniques to master direct anterior composite restorations: an update

Abstract

Creating perfect direct composite restorations has been for long time a strict challenge due to many materials' limitations impacting either shade integration or surface quality, and possibly colour stability. Next to technological drawbacks, a certain complexity and lack of predictability in clinical application was inherent to the technique and made it elitist for a long time. Shading and layering concepts then progressively evolved from a simplistic, non histo-anatomical, bilaminar technique to a multi-layering approach (3 to 4 or more layers), following the Vita Classic system. One of the most achieved concepts is polychromatic layering which makes use of a variable number of layers (basically VITA or non-VITA opacious dentin, chromatic enamel and translucent/opalescent enamel), driven by the natural tooth optical composition. In parallel with this evolution, a simplified, non-VITA shading system was developed with a reduced number of layers (basically dentin &enamel layer, plus effect shades if required) known as the natural layering concept, aiming to the same optimal esthetic integration and natural colour reproduction/emulation. The latest improvements appear all driven by the same view of improved reliability and clinical simplification.

Resin composite thickness’ influence on L*a*b* coordinates and translucency

“…The choice of three different composite materials resulted from the need to use and test specific opacity and color gradients which could not be found in one single restorative system; then, one dentin shade, one body shade, and one achromatic enamel from three brands and companies were selected for this study [1]. We wanted, in fact, to investigate if color variation and transparency varied independently of the composite's transparency.…”

“…This is why proper color selection and layering technique are key points to success. Numerous layering concepts have actually been developed which make use of different opacity and color gradients, resulting in various number of layers used tentatively to match the tooth shade [1][2][3][4]. In consideration of the variability in the specific optical properties of these many composite shades, no study so far investigated the possible influence of resin composite's thickness on the color of each layer or the final restoration as a whole.…”

Estratificação incremental com resina composta: reprodução de efeitos ópticos incisais em restauração classe IV

“…Para tanto, o cirurgião-dentista deve estar consciente da morfologia e anatomia dos tecidos dentários, das propriedades das resinas compostas de escolha e principalmente da interação da luz com a restauração. Além disso é imprescindível uma correta seleção de saturação da cor como também determinar a correta espessura da proporção esmalte/dentina, levando-se em consideração a quantidade e a posição dos incrementos 2,3,7,9,12,[19][20][21][22][23] .…”

“…Restaurações diretas com resina composta em dentes com terço incisal translúcido têm sido um desafio para o dia-a-dia clínico do odontólogo. Apesar de suscitar grande interesse nos profissionais, em muitas situações o resultado final obtido numa restauração deste tipo pode não superar as expectativas do operador, visto à dificuldade da correta estratificação das diferentes camadas de compósito, que visam mimetizar à anatomia dental [1][2][3][4][5][6][7] . O sucesso clínico desse tipo de procedimento depende da seleção de materiais e técnicas que emulam o dente natural e proporcionam estabilidade a longo prazo nas características ópticas 8,9 . Os compósitos vêm evoluindo ao longo dos anos no que diz respeito à optimização das suas propriedades ópticas e mecânicas, bem como ao desenvolvimento de novas técnicas 10 .…”

Minimally invasive rehabilitation of the worn dentition: a case report utilising adhesive additive techniques and digital technologies

“…The goal was to create restorative space in the labial aspects (cutback) and also to create a 2.0 mm long 45‐degree bevel to aid the concealment of the tooth to composite resin transition . The labial aspects of the maxillary anterior teeth were then restored utilising two shades of composites of differing opacities (Essentia MD and DE; GC Corporation) following the ‘Natural Layering Concept’ . Free‐hand layering was completed utilising the following protocol.…”