Biomechanical analysis of four types of short implant
vendredi 2 novembre 2018
Posted by: Paola Pino
Short implants are now being used more widely, though there is still much to be learned about their use. For instance, whether crown-to-implant ratios for short implants increase in the alveolar ridge and clinical outcomes are still open to question. This study, a joint effort between researchers from Switzerland and South Korea, aimed to understand the stress and strain distribution for short implants with different platforms
The study involved four different implant types which were categorised into the following groups: internal bone-level platform (IB), external bone-level platform (EB), tissue-level regular platform (TR), and tissue-level wide platform (TW). All implants were 4.5mm in diameter and 7mm in length. Data from the implants was used to create a digital 3D model. The 3D models were implanted into a digital reconstruction of the mandibular area which was reconstructed from CT data.
After modelling, a finite element analysis was carried out to simulate a 90-degree vertical load and a 30-degree oblique load. The researchers were then able to assess the strain and stress levels on the implant, abutment and screw. They were also able to see the strain on cortical and trabecular bone.
It was observed that tissue-level platforms showed the most favourable results in terms of stress on the implant component, though they showed high stress on cortical bone. There was no significant strain difference for oblique loading but internal-bone level implants showed the lowest strain under vertical loading. Many of the implants used in the study were either grade 4 or 5 titanium. According to the results the stress on the IB abutment was close to the yield strength of titanium grade 4. Therefore, the study recommended using caution when using grade 4 titanium IB type abutments with long crowns.
This study was presented as an e-poster at the 2017 EAO Congress.