Esthetic and functional long-term prototypes utilizing high-strength bis-acryl resin

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Figure 1: Occlusal view showing extensive and deficient restorations — **Figure 1:** Occlusal view showing extensive and deficient restorations

The esthetic rehabilitation of worn dentition poses a great challenge to clinicians. Several treatment planning approaches and restorative materials are used to treat tooth wear. Clinicians should be able to select the most suitable treatment planning methods and materials for individual patients, depending on their specific etiology and risk factors.^1,2

Esthetic functional prototypes have been utilized to test drive the proposed smile design, vertical dimension, phased treatment plan, and functional blueprint for future care.^3–5 Different materials and techniques have been used to create bonded functional prototypes, such as polymethyl methacrylate (PMMA) and highly filled flowable composites.^6–9

Figure 2: Occlusal view showing extensive and deficient restorations — **Figure 2:** Occlusal view showing extensive and deficient restorations

A new generation of bis-acryl resin material is available for fabrication of semipermanent crowns, long-term prototypes, and various uses such as pediatric crowns and palliative care. A university-based study showed flexural strength of approximately 110 MPa and volumetric wear similar to that of conventional composite.¹⁰ This article describes a direct-indirect technique to

Figure 3: Lateral pre-op view showing discolored teeth — **Figure 3:** Lateral pre-op view showing discolored teeth

fabricate esthetic and functional prototypes for full-mouth restorations.

Case description

A patient presented with multiple deficient restorations, discolored teeth, and attrition (figures 1–4). The patient’s treatment plan was a full-mouth rehabilitation with a combination of veneers, crowns, and onlays.

Figure 4: Lateral pre-op view showing discolored teeth — **Figure 4:** Lateral pre-op view showing discolored teeth

A digital wax-up was designed in the CAD software, and a 3-D printed model was obtained (figure 5). Putty matrices were made using Honigum Pro Putty with Light Body (DMG America), and high-strength bis-acryl resin (LuxaCrown; DMG America) was injected into the matrix (figure 6) and placed in the patient’s mouth over the prepared teeth.

Figure 5: 3-D printed models of diagnostic wax-up — **Figure 5:** 3-D printed models of diagnostic wax-up

The prototypes were removed, and excess material was trimmed extraorally with carbide finishing burs and polished

Figure 6: LuxaCrown injected into a PVS matrix — **Figure 6:** LuxaCrown injected into a PVS matrix

(figure 7). After that, prototypes were sectioned in quadrants and then bonded using flowable composite (LuxaFlow; DMG America; figure 8). Occlusion was adjusted as needed, and the bonded prototypes were tested for six months. The final ceramic restorations were finished in a sequenced approach (figures 9–12).

Figure 7: Finished LuxaCrown prototypes — **Figure 7:** Finished LuxaCrown prototypes

Conclusion

Esthetic and functional prototypes are an effective way to evaluate esthetics and function of a proposed restorative plan, all while spreading the cost of definitive treatment over time. Esthetic, functional, and long-lasting restorations can be achieved if clinical and laboratory protocols are carefully followed using adhesive additive techniques.

Figure 8: Bonding of prototypes with LuxaFlow — **Figure 8:** Bonding of prototypes with LuxaFlow

References

1. Calamita M, Coachman C, Sesma N, Kois J. Occlusal vertical dimension: treatment planning decisions and management considerations. Int J Esthet Dent. 2019;14(2):166-181.

2. Fradeani M, Barducci G, Bacherini L, Brennan M. Esthetic rehabilitation of a severely worn dentition with minimally invasive prosthetic procedures (MIPP). Int J Periodontics Restorative Dent. 2012;32(2):135-147.

Figure 9: Lateral view of bonded functional prototypes — **Figure 9:** Lateral view of bonded functional prototypes

3. Gürel G, Bichacho N. Permanent diagnostic provisional restorations for predictable results when redesigning the smile. Pract Proced Aesthet Dent. 2006;18(5):281-286.

4. McLaren EA, Schoenbaum TR. The bonded functional esthetic prototype: part 1. Inside Dent. 2013;9(1):70-74.

Figure 10: Lateral view of bonded functional prototypes — **Figure 10:** Lateral view of bonded functional prototypes

5. McLaren EA. The bonded functional esthetic prototype: part 2. Inside Dent. 2013;9(5):84-92.

6. Terry DA. Restoring with Flowables. Hanover Park, IL: Quintessence Publishing Co.; 2017.

7. Hemmings KW, Darbar UR, Vaughan S. Tooth wear treated with direct composite restorations at an increased vertical dimension: results at 30 months. J Prosthet Dent. 2000;83(3):287-293. doi:10.1016/s0022-3913(00)70130-2

Figure 11: Pre-op frontal view — **Figure 11:** Pre-op frontal view

8. Gürel G, Bichacho N. Permanent diagnostic provisional restorations for predictable results when redesigning the smile. Pract Proced Aesthet Dent. 2006;18(5):281-286, 316-317.

Figure 12: Frontal view of bonded prototypes — **Figure 12:** Frontal view of bonded prototypes

9. Baroudi K, Rodrigues JC. Flowable resin composites: a systematic review and clinical considerations. J Clin Diagn Res. 2015;9(6):ZE18-ZE24. doi:10.7860/JCDR/2015/12294.6129

10. Sulaiman T. Novel semi permanent restorative material, wear, post fatigue, and mechanical properties. University of North Carolina; June 2019.

Celin Arce, DDS, MS, FACP, a board-certified prosthodontist, received his dental degree from University Latina of Costa Rica. He completed a residency in advanced prosthodontics at the University of Alabama (UAB) at Birmingham and a master of science in clinical dentistry. A diplomate of the American Board of Prosthodontics and fellow of the American College of Prosthodontists, Dr. Arce serves as assistant professor of the restorative sciences department at UAB School of Dentistry.