Non-Destructive Micro-CT Evaluation of the Metal–Porcelain Junction in a Zirconium-Alloy Metal–Ceramic Bridge Restoration

Amasya H.

European Congress of DentoMaxilloFacial Radiology 2026, Iasi, Romanya, 25 - 27 Haziran 2026, ss.115, (Özet Bildiri)

  • Yayın Türü: Bildiri / Özet Bildiri
  • Basıldığı Şehir: Iasi
  • Basıldığı Ülke: Romanya
  • Sayfa Sayıları: ss.115
  • İstanbul Üniversitesi-Cerrahpaşa Adresli: Evet

Özet

Aim: This study aimed to evaluate the microstructural characteristics of a zirconium-alloy metal–ceramic bridge restoration and the integrity of the metal–porcelain junction (MPJ) using non-destructive micro-computed tomography (micro-CT).

Materials and Methods: A three-unit implant-supported zirconium-alloy metal–ceramic bridge restoration (teeth 24–26) was examined using a NXL micro-CT system (NeoScan, Belgium). The tube voltage was 150 kV and two scanning protocols were applied. In the first protocol, the tube current was 200 μA with a pixel resolution of 15 μm; in the second, the current was 90 μA with a resolution of 7 μm. The first 360° scan required 1 hour 28 minutes with 0.4° rotation steps, while the second required 4 hours 48 minutes with 0.25° steps. NeoScan software was used for acquisition, GPU reconstruction, visualization, and local thickness analysis, and VoxRay software for additional iterative reconstruction. The metal framework and porcelain veneer were evaluated for structural homogeneity and defects at the MPJ. No human or animal subjects were involved.

Results: The restoration showed a multilayer structure consisting of a zirconium-alloy metal framework, a porcelain veneer, and a thin interface layer. Micro-CT revealed internal pores and low-density inclusions in both materials. Localized air gaps were also detected at the MPJ, particularly around the junction areas of the metal-supported crowns.

Conclusion: Non-destructive micro-CT analysis revealed interfacial defects at the MPJ. These air gaps may weaken interfacial bonding and contribute to metal–porcelain detachment in metal-supported bridge restorations.