Assistant Professor Western University London, Ontario, Canada
Purpose of the Study: Dental implant components are typically fabricated using subtractive manufacturing, often involving metal materials that can be costly, inefficient, and time-consuming. This study explores the use of additive manufacturing (AM) with zirconia for dental implant overdenture bars, focusing on mechanical performance, stress distribution, and fit.
Methods: Solid and lattice-structured bars were designed in Fusion 360 and produced using LithaCon 210 3Y-TZP zirconia (Lithoz GmbH, Vienna, Austria) on a CeraFab 8500 printer. Post-processing included cleaning, debinding, and sintering. A 3D-printed denture was also fabricated to evaluate fit. Thermography and optical imaging were used to assess adaptation. Custom fixtures were developed for flexural testing, and fracture loads were recorded to calculate stress distribution using finite element analysis (ANSYS R2025). The FEA model assumed isotropic, homogeneous, linear-elastic material behavior. Bars were torqued to 15 Ncm on implant analogs.
Results: The average fracture loads were 1.2240 kN (solid, n = 12) and 1.1132 kN (lattice, n = 5), with corresponding stress values of 147 MPa and 143 MPa, respectively. No statistically significant difference was observed (p = 0.578; α = 0.05). The fracture occurred near high-stress regions at fixture support points. All bars demonstrated a clinically acceptable fit on the model; however, further validation and clinical evaluation are still needed.
Conclusion: Additively manufactured zirconia bars, including lattice structures, show promise as alternatives to conventional superstructures, potentially offering reduced material use and faster production without compromising mechanical performance.
Articles: Emami, E.; De Souza, R.F.; Kabawat, M.; Feine, J.S. The impact of edentulism on oral and general health. Int. J. Dent. 2013, 2013, 498305. [CrossRef] 2. Asvanund, C.; Morgano, M.S. Restoration of unfavourably positioned implants for a partially edentulous patient by using an overdenture retained with a milled bar and attachments: A clinical report. J. Prosthet. Dent. 2004, 91, 6–10. [CrossRef] 3. Jivray, S.; Chee, W. Rationale for dental implants. Br. Dent. J. 2006, 200, 661–665. [CrossRef] 4. Galindo, D. The implant-supported milled-bar mandibular overdenture. J. Prosthodont. 2001, 10, 46–51. [CrossRef] 5. Mosnegutu, A.; Wismeijer, D.; Geraets, W. Implant-supported mandibular bone resorption in edentulous patients: Results of a long-term radiologic evaluation. Int. J. Oral Maxillofac. Implants 2015, 30, 1378–1386. [CrossRef] [PubMed] 6. Rismanchian, M.; Bajoghli, F.; Mostajeran, Z.; Fazel, A.; Eshkevari, P. Effect of implants on maximum bite force in edentulous patients. J. Oral Implantol. 2009, 35, 196–200. [CrossRef] [PubMed] 7. De Kok, I.J.; Chang, K.H.; Lu, T.S.; Cooper, L.F. Comparison of three-implant supported fixed dentures and two-implant-retained overdentures in the edentulous mandible: A pilot study of treatment efficacy and patient satisfaction. Int. J. Oral Maxillofac. Implants 2011, 26, 415–426. [PubMed] 8. MacEntee, M.I.; Walton, J.N.; Glick, N. A clinical trial of patient satisfaction and prosthodontic needs with ball and bar attachments for implant-retained complete overdentures: Three-year results. J. Prosthet. Dent. 2005, 93, 28–37. [CrossRef] 9. Campos, C.H.; Concalves, T.M.S.V.; Garcia, R.C.M.R. Implant-supported removable partial denture improves the quality of life of patients with extreme tooth loss. Braz. Dent. J. 2015, 26, 463–467. [CrossRef]
