How often do we encounter heavily stained anterior teeth in dental practice? Nearly every clinician has come across that problem at least once. In such cases, an invasive approach is usually required (the teeth need to be prosthetically restored with ceramic veneers or even crowns). However, since the concept of 'minimal invasiveness' has attained a following recently, it might be a good idea to start rethinking our ways of dealing with stained anterior teeth. Today's state-of-the-art composites enable dental professionals to use minimally invasive treatment protocols and achieve outstanding restorative results.
Training courses held on the subject of aesthetic dentistry usually focus on three basic aspects: shape, shade and surface texture. These are the three indispensable pillars without which the aesthetic restoration of anterior teeth would be impossible. However, in most cases attention is only paid to one of the aspects, namely shade. Why is this so? This article will show how all the three elements can be taken into account in order to achieve an aesthetic outcome.
Preoperative situation
A female patient presented to our dental practice with a stained central incisor (Figs 1 and 2). She refused to have the tooth prosthetically restored with ceramic material and expressed her desire to receive minimally invasive treatment. We decided to apply a direct restorative technique using state-of-the-art composite resin (IPS Empress Direct).
Initial steps and tooth preparation
As the degree of tooth discolouration varied from mild to medium, a preparation depth of 0.3mm to 0.5mm was sufficient. Following minimally invasive preparation, a retraction cord was placed to prevent contamination of the working field with sulcus fluid (fig 3). When fabricating layered restorations, the application of the adhesive is the step most prone to error. Therefore, it is advisable to use an adhesive system that is easy-to-use, but provides reliable adhesion. In the case presented, we decided to use ExciTE F adhesive. After having conditioned the enamel with phosphoric acid gel (Total Etch) for 30 seconds, the adhesive was brushed into the tooth structure for 10 seconds (fig 4) and blown to a thin layer with a weak stream of air. Subsequently, the adhesive layer was light-cured for 10 seconds with the bluephase curing light using the Low Power mode. Then the first composite layer was placed. In order to achieve optimum masking, we chose to use the opaque B2 shade from the IPS Empress range of dentin materials.
Layering
Mimicking the shape and shade of natural teeth is a huge challenge and requires considerable attention to detail. To achieve the same reflections as those of natural teeth, the dentin shade was applied in an arch-like fashion. As the composite material readily adapted to the preparation margins, only light pressure with the modeling spatula (fig 5) had to be applied. The composite increment was deliberately moulded with a slight taper towards the centre of the tooth. In this way, an invisible transition to the subsequently placed increments was ensured (fig 6).
Then the composite was light-cured with the bluephase curing light for 15 seconds using the Soft Start mode.
After having moulded the gingival 'arch', which outlined the gingival margin of the veneer, the proximal portions were moulded in a similar fashion. As each layer was thinned out, the different shades and shapes blended well into each other (fig 7). Once the mamelon-type increment had been placed in the centre, the discolouration was completely masked. In the proximal and central areas, shade A1 Dentin was used.
To copy the appearance of the adjacent teeth, a translucent opalescent material was applied along the incisal edge. Finally, the entire composite build-up was covered with a layer of IPS Empress Direct B1 Enamel as indicated in the layering scheme (figs 8 to 10).
Finishing
To closely reproduce the morphology and anatomy of natural teeth, just as much effort should be applied in finishing the restoration as in layering it. Following polymerisation, attention was paid to creating an optimal surface texture. First, the restoration was pre-contoured with fine-grit burs to remove possible composite excess. Fine-grit instruments provided the advantage of allowing an optimal shape to be achieved in a controlled fashion. Moreover, the inadvertent creation of undesirable retentions or depressions was avoided. After pre-contouring the restoration, finishing and polishing was performed using the Astropol system (fig 11).
Conclusion
With state-of-the-art composites such as IPS Empress Direct, natural-looking restorations can be created. Easy to-use materials in combination with individual layering schemes enable minimally invasive treatment procedures to be employed, even in cases where indirect restorations would normally be indicated. By choosing a suitable restorative and following the treatment protocol described in this article, the three pillars of esthetics can be taken into account in the restoration of anterior teeth (figs 12 and 13).