Title: The management of severe toothwear with composite injection moulding utilising a digital workflow
Abstract:
Introduction: Toothwear is the progressive loss of dental hard tissue due to physical and/or chemical processes and may result from attrition, erosion, abrasion, or a combination of these mechanisms. Depending on its severity, toothwear can have a significant impact on both dental function and aesthetics. Restoration of worn dentition using additive techniques can provide a minimally invasive approach to re-establishing tooth morphology and function. Composite injection moulding is a relatively new technique that allows predictable reproduction of a planned wax-up. The integration of intraoral scanning, digital wax-ups and 3D-printed models can further facilitate accurate pre-operative planning and clinical execution.
Case Presentation: A 43-year-old male presented with significant toothwear, predominantly affecting the upper anterior dentition. He reported increasing concern regarding the aesthetics of his teeth and mild sensitivity to cold over the preceding few months. Relevant risk factors included high levels of stress, with associated potential parafunctional activity, and a previous high intake of carbonated beverages. At presentation, he was not using a protective occlusal splint. Following assessment and discussion of treatment options, an additive restorative approach was planned. Composite build-ups of the upper and lower anterior teeth (UR3–UL3 and LR3–LL3) were proposed at an increased occlusal vertical dimension. An intraoral scan was used to facilitate digital treatment planning and design of the proposed wax-up, which was subsequently 3D printed to aid clinical planning. Composite injection moulding was selected to transfer the planned tooth morphology predictably to the patient's dentition using a carefully designed wax-up and injection moulding stent. The posterior dentition was subsequently monitored to allow adaptation to the planned increase in occlusal vertical dimension, following the principles of the Dahl concept.
Conclusion: This case demonstrates the potential benefits of integrating digital workflows with additive composite techniques in the management of localised anterior toothwear. Intraoral scanning and digitally designed, 3D-printed models can facilitate predictable treatment planning, while composite injection moulding allows conservative restoration of tooth morphology with an emphasis on both function and aesthetics. Successful management of toothwear requires not only restoration of lost tooth tissue but also identification and management of underlying risk factors to improve the long-term prognosis of the restorative treatment.
