How to Treat Severely Eroded Anterior Teeth: The Additive Approach
- Jeff Davies
- Nov 29, 2015
- 3 min read
Photo Courtesy of The European Journal of Esthetic Dentistry. (http://www.ncbi.nlm.nih.gov/pubmed/19655550)
There are a few biomechanics and occlusal principles that help optimize the conservative treatment philosophy. This post will discuss one of them. Cases where severely eroded and worn anterior dentition are best served with adhesive restorations rather than retentive restorations. Enamel and dentin bonding along with resin composites can lead to optimal results for esthetic and functional aspects. Deep bite and palatal erosion cases can lead to the most challenging cases. Instead of extreme reducing on the palatal surfaces, a simplified technique can be applied. Occlusal therapy combining centric relation and Dahl principles can be used to create enough anterior interocclusal space that is needed. This allows for an ultraconservative treatment that follows the biomimetic principles. In cases with severe dental erosion, dentin sealing with a filled dentin bonding agent has been proven to be the most conservative approach to reduce the rate of wear. The ideal restoration will include restoring the form, function, and esthetics which can be accomplished by adhesive dentistry. There are biomechanical and occlusal principles that will aid in the selection of adhesive materials and techniques for the treatment of severe enamel loss in the anterior dentition.
Enamel and dentin are the two materials that give the tooth the unique ability to withstand the masticatory and thermal loads acquired during a lifetime. Enamel is fragile and cracks easily but is able to withstand occlusal wear. Dentin is flexible but is not wear resistant and ages poorly. Natural teeth have the optimal combination and offer the best compromise between stiffness, strength, and resilience. Great steps in research happened when the focus was on the biomechanical side effects of enamel loss and enamel preparations. Enamel loss can make the tooth more deformable and the tooth can be strengthened by increasing its resistance to crown deformation. These have been shown in numerous studies that focus on the biophysical stress and strain. It used to be that tooth reinforcement was first achieved by some form of full or partial coverage, extra-coronal strengthening. This reinforcement would come at the expense of the intact tooth with its vital tooth structure. Advancements in adhesive dentistry have provided reestablishing crown stiffness and while allowing maximum preservation of the remaining hard tissue in teeth. Bonded composite has been shown to permit tooth stiffness but it isn't ideal. The elastic modulus, is one limitation, in which for an average microfilled hybrid can only provided 1/8 - 1/4 of the elastic modulus of enamel. Which means it isn't as strong as enamel. Porcelain has been shown to have a similar elastic modulus as compared to enamel. Porcelain has been instrumental in enamel replacement by providing a similar structure to distribute stress throughout the crown. Porcelain veneers have proved to balance the functional stress of the anterior dentition.
Restoring severe enamel loss due to erosion, should be an esthetic and biomechanical endeavor. Restoring these eroded teeth shouldn't need much of an enamel reduction due to enough space being provided by the already missing enamel. This can be termed an additive approach. The success of a biomimetic approach relies on the bond between the porcelain and the luting resin composite and the luting resin composite to the tooth. Once again, this is where the importance of immediate dentin sealing come in to play to allow for better adhesion to the dentin which is so important. Immediate dentin sealing appears to achieve bond strengths, fewer gap formations, and decreased sensitivity. The use of IDS should be preformed when placing indirect bonded restorations such as composite/ceramic inlays, onlays, and veneers. While severe loss of enamel constitute an alteration to the function, mechanics, and esthetics of the anterior teeth, it is also an opportunity for the additive restoration of the missing tissues. Adhesive dentistry is the best option in these scenarios. The additive approach to restore the tooth to the existing biomechanical values should be considered when treating these types of cases. Adding too the tooth rather than subtracting can be a different way to look at a case while achieving optimal values.
All material was based on this article written by Dr Pascal Mange et al. It is a very informative paper and is suggested to read in its entirety.
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