Nexus Prosthetic Concept
What makes Nexus prosthetics different from other styles and suppliers?
Nexus frameworks are Designed and Milled by industry-leading implant-prosthetic company, Osteon Medical.
They differ from other offers on the market by being:
Expertly designed with strict parameters.
Using industrialized milling accuracy.
Thousands of patient-matched cases completed.
Structural Theory
Nexus Hybrid Support Structure
The Nexus “lingual ledge” supports the overlay material by providing even support across the arch.
The titanium bar is designed to absorb occlusal forces across the occlusal table.
2-Piece Monobloc-Milled Assembly
Nexus final prosthetics are designed around the idea of two precision-milled pieces:
A titanium framework
A monolithic overlay material
By utilizing male and female parts that match one-another the occlusal forces applied to the tooth-material are easily and evenly distributed to the underlying titanium framework.
2-Piece Design
Monolithic Zirconia overlay, monobloc milled Grade V titanium framework.
Superior Material Bonding
The Nexus prosthetic concept makes drastic improvements to material bonding due to a variety of factors, predominantly the full utilization of cementation contact due to increased surface area.
Typical Full-Arch Ti Base
~136 Square Millimetres of cementation surface area.
x4 implants = 544sqmm
Nexus Hybrid Bar
2,190sqmm
Resulting in 3-4x as much surface area for cementation bonding.
Accommodating Implant Challenges
Sometimes implants require placement at angles that are not ideal for prosthetic function and longevity. These can cause a variety of issues when relying on conventional Ti-base restorations.
Unsupported Angles
Conventional Ti base use cannot accommodate for anteriorly angled implants. Resulting in unsupported tooth-material.
Angled Nexus Framework
The Nexus substructure is modified to accommodate for the angles and unique occlusal forces of the patients, despite sub-optimal implant placement.
Prosthetic Chimney
Subgingival implant placement requires a “chimney” to meet the abutment, ideal for aesthetics and hygiene, but not great for strength relying on a thin neck of zirconia.
Contours and Strength
The precision milling of the Nexus frameworks can meet implants at any level without sacrificing strength, tissue conditioning or aesthetics.
Digital Review, Advanced Understanding
The use of the case approval process ensures that all designs can be understood by technician and clinician. Importantly, the introduction of the bar, highlighting screw channels and minimum thickness standards ensure the best prosthetic outcome for the patient.
Bar Design Approval
Maxillary case with bar design to match tooth setup, utilizing patient tissue and antagonist scans.
Red cylinders represent screw channels where Biaxial angled screw correction (ASC) may be used.
Digital Design, Digital Analysis
The Nexus prosthetic concept was conceived to accomodate for a variety of limitations in conventionally used full-arch prostheses. Even wrapround-style prosthetics using milled bars. Firstly by applying engineering methodologies like using finite element analysis (FEA).
The below FEA analysis images show titanium bar supported bridges, applying force to the distal cantilever molar region, simulating bite forces.
Conventional Wraparound: Milled Titanium Bar with Retention Pins and processed acrylic denture teeth.
Nexus Hybrid: Milled Nexus framework with monolithic PMMA overlay material.
Practical Comparison, Peer Reviewed
Following internal studies and market use, the Nexus bar and overlay design was examined as a part of a study by Melbourne University.
The study compared two distinct prosthetic styles under cyclic loading to mimic years of chewing function on the molar with a 10mm distal cantilever.
Conventional Pin-Retained Wraparound
Conventional wraparound bridges using composite infused PMMA and processed acrylic.
“9 Conventional prosthesis failed at the same load increment (1,000 N) and once conventional prosthesis failed at 1,150 N.”
Nexus Hybrid PMMA Cantilever Bridge
Nexus style bridges with PMMA overlay.
“The digital prosthesis (Nexus) group failed at approximately 50% higher loads, where the lowest failure increment was 1,400 N. The digital prosthesis group fractured at a significantly higher number of cycles (124,857 ± 21,608) than the conventional group (28,452 ± 6,559).
In order to fracture, the digital prosthesis required more than 4 times the number of cycles of the conventional prostheses.”
For further explanation and results of the study, see:
El-Haddad, H. et al. (2020) ‘Laboratory evaluation of novel implant metal-acrylic prosthesis design: Influence of monolithic acrylic veneer’, The International Journal of Oral & Maxillofacial Implants, 35(1), pp. 100–106. doi:10.11607/jomi.7545.
