Dental implants are the best replacement option for missing teeth. And they have proven able to last 20 years or more on a regular basis. However, as more people get dental implants at younger ages, they demand better function, even as their implants have to last longer as lifespans continue to increase. This means that dental implants will have to stand even more stress cycles–every time you bite down, you stress the implants. Unfortunately, repeated loading can weaken titanium implants, especially when combined with corrosion. Over time, this can increase dental implant failures related to mechanical stress. Although overall only about 0.2% of dental implants fail due to fracturing, the fracture rate increases with time, and becomes an increasing concern.
Now, though, researchers have applied a new processing technique to increase dental implants’ resistance to loading fatigue and corrosion.
Keep Back the Crack
The problem with fatigue loading is that small cracks initiated during loading will grow into larger cracks over time. This can happen with either high-level force applied over relatively few loading cycles, or it can happen over the course of many cycles with relatively light loads.
Pure titanium is susceptible to these cracks because it tends to have large grains. These grains can be easily split by the cracks, as opposed to small-grained material where the grain boundaries absorb energy and deflect cracks.
One way to create smaller grains in titanium is to alloy it with other metals. Although this does improve the strength significantly, it can hamper osseointegration. So researchers looked for another way to create smaller grains.
They found that they could create the smaller-grained titanium through the use of severe plastic deformation (SPD) processing. By applying severe shear deformation with high pressure during the manufacturing process, researchers were able to transform the microstructure of the titanium, increasing the tensile strength between two and three times.
They found that with this processing technique, implants were able to resist cracking under both high forces and low force loads.
They even put the implants in simulated body fluids to see if corrosion impacted their durability. The specially processed implants were unaffected by the corrosive medium.
Dental Implants Are Great–and Getting Better
Dental implants have already demonstrated that they can regularly last over 20 years, and in some cases they can last over 40 years. With improved technology, they will more regularly be capable of lasting the 40, 50, or 60 years that people count on them.