Article
Contemporary operative treatment focuses on minimally invasive techniques to restore natural form, function and aesthetics, sacrificing minimal tooth substance to sustain tooth vitality. This philosophy is a popular approach for the management of toothwear,1-4 shown to be increasing in both adolescent and adult populations.5,6 This ‘clinical tip’ will describe techniques to achieve predictable clinical and patient outcomes using direct composite resin restorations.
Case report
A 28-year-old male presented with generalized moderate toothwear of erosive and attritive origin (Figures 1 and 2). Having identified the aetiology and completed a course of preventive treatment, review and maintenance, the maxillary anterior teeth were planned for direct composite restorations.
Study models were mounted via a facebow transfer to a semi-adjustable articulator on which a diagnostic wax-up increased the incisal length and occlusal vertical dimension (Figure 3). To assess the aesthetics, phonetics and occlusion, a vacuum-formed matrix was fabricated from the wax-up and transferred to the mouth using Bis-Acrylic resin (Figures 4–6). This provided an excellent opportunity for informed consent. Aesthetic assessment tools have been described elsewhere,7,8,9,10 in this case, some minor adjustments were made to incisal length relative to the lip line, palatal contour in mandibular excursive movements and posterior occlusal contacts.
The palatal form of these customized diagnostic restorations was then copied using a translucent addition silicone impression material (Figure 7). Contrary to an opaque putty matrix, this will permit initial curing of composite resin, preventing drag of uncured composite when removing the matrix.
Posteriorly, the diagnostic restorations were removed, and using callipers their minimum thickness measured to help inform a definitive restorative material decision (Figure 8).
When using a composite layering technique to restore optical and anatomical characteristics, without removal of sound tooth tissue, more than one shade is necessary. Cervical third and incisal third colours guide dentine and enamel shade selection, respectively.11 Quickly layering the selected shades on unbonded tooth structure facilitates patient consent and can be easily changed to prevent disappointment in the final restoration. For definitive composite placement, a split dam technique was used to allow seating of the matrix supported by the palate. Furthermore, the clinician has both hands free to concentrate on composite placement rather than moisture control (Figure 9).
The maxillary anterior teeth were cleaned with Prophy Paste in a rubber cup, the cervical ring of enamel is critical for bonding and therefore preparation was avoided. Phosphoric acid (37%) was applied to enamel and dentine for 30 seconds and 15 seconds, respectively. A dentine-bonding agent was applied and cured as per manufacturer's instructions. To visualize and reproduce symmetrical restorations, tooth pairs were restored simultaneously: canines, central incisors and, finally, lateral incisors (Figure 10). There are many types of inter-dental matrices, this can be down to clinician preference, but a composite saw will destroy the contact point.
Finishing is a time consuming process, oversight will result in suboptimal aesthetics, staining accumulation, and poor marginal seal.12,13 A 50 micron diamond polishing bur carved initial geometric outline and removed flash. Fine polishing discs can remove surface texture so were used briefly, followed by white stones. Proximal areas were polished with fine discs followed by fine plastic interproximal finishing strips. Polishing paste used wet then dry produced a gloss finish (Figure 11).
Posterior occlusion was immediately restored with the diagnostic Bis-Acrylic restorations (Figure 12), subsequently definitive restorations were adhesively bonded in place.
