Stress distribution in zirconia dental implants

Researchers have compared Zirconia implant designs with different abutment screw materials to understand how stresses are distributed under load.

Zirconia dental implants have been suggested as an alternative to titanium. These implants are available as one-piece or as bone-level or tissue-level two-piece designs with different connection types and abutment screw materials.

In this study, researchers used a simulation model to analyse how stresses are distributed in five zirconia implant designs. The study was carried out as a collaboration between Malmö University, NIOM, Umm Al-Qura University (Saudi Arabia), and Det Tekniske Bureau (Denmark).

“We wanted to understand where high stresses occur in different implant designs, and how design and material choices influence these patterns,” says Abdulaziz Gul from Malmö University.

What did the researchers find out?

The simulations showed differences between implant designs.

One-piece implants had higher stress concentrated in the implant body, especially in the thread region. Two-piece implants distribute stress across the implant system, including the abutment and screw, and transfer more stress to the preimplant structure.

Within two-piece designs, tissue-level implants showed lower stress levels than bone-level designs. The type of screw also mattered. Designs with ceramic screws showed higher local stress in the interface between the screw and the abutment compared to designs with titanium screws.

What are the key results/main findings?

The study shows that implant design affects how stresses are distributed under load.

One-piece implants concentrate stress in the implant body, whereas two-piece implants show less stress in the implant body and more stress in the connection between components. Tissue-level designs appear to reduce overall stress compared to bone-level designs.

The results also highlight that the geometry of the screw–abutment connection plays an important role. More stress was observed in designs with ceramic abutment screws than in designs with a titanium abutment screw, especially at the screw–abutment interface.

“Understanding how stresses are distributed helps us interpret clinical complications and supports better design choices,” says Professor and NIOM CEO Per Vult von Steyern.

Click here to read the full research article