After receiving your final prosthesis, you will feel delighted with the results. However, it is essential to be aware of possible complications, both biological and technical. Below, we discuss the nine most common technical complications of full-arch prostheses. While they might appear dramatic to the patient, these complications are typically easily manageable with professional care.

Chipping or Fractures of the Teeth or Artificial Gum

This is by far the most common complication. It can occur due to multiple reasons.

Early failures often happen soon after the prosthesis is fitted. They are usually caused by errors in design or manufacturing or attempts by the patient’s musculature to adapt to the new prosthesis. Late failures typically occur years later due to material fatigue from chronic use. Design or manufacturing defects (though rare) can also contribute.

Wearing a nightguard strictly every night without exception can significantly reduce the risk. Unfortunately, most repairs require sending the prosthesis back to a dental laboratory as they are too complex for direct repair at the chairside.

Complete Fracture of the Prosthesis

A relatively “common” complication, especially in PMMA (plastic) or hybrid (metal-acrylic) prostheses (where the acrylic part may fracture). Even ceramic prostheses, which are known to be very strong and hard, such as zirconia, can fracture under extreme conditions. In most cases, a new prosthesis will be required, often involving a significant investment. Using a nightguard can help reduce, but not eliminate, this risk.

Fracture of the Metal Substructure

Fractures of the internal metal framework can occur, often due to errors in design or manufacturing. When this happens, a new prosthesis will be necessary. This is quite a rare incident, and although mentioned in the literature, it is unlikely to be seen in practise.

Fracture of Prosthetic Abutments

Most full-arch prostheses are supported by prosthetic abutments rather than being directly attached to the implants. This adds a fail-safe component between the prosthesis and the implants. Fractured abutments can be replaced easily in the dental surgery as they are standardised components.

Fracture or Loosening of Screws

Another relatively common issue, screw fractures or loosening can be addressed in the dental surgery. A lot of the time, some minor bite adjustments may be required. If this happens often, it could indicate a design flaw or more often, excessive grinding (bruxism) by the patient.

Fracture of the Implants

While implant fractures are not common, they are also not unheard of. Unfortunately, they are a relatively serious complication requiring at least the disconnection of the fractured implant from the prosthesis as a minimum. Additional implants and a new prosthesis may be necessary, depending on the case.

Discolouration of Acrylic or Composite Teeth

The diet of the patient plays a significant role in the discolouration of acrylic or composite teeth and sometimes the surrounding pink gum. Typically, discolouration starts to become noticeable about five years after placement. A refurbishment procedure at the dental laboratory will revive most of the aging prostheses and will return them to their previous lustre. Ceramic full-arches, by comparison, do not have this issue.

Loss of Fillings Blocking Screw Access Holes

All-on-4 prostheses are usually screw-retained, with access holes on the biting or palatal surfaces of the teeth or the gum part of the prosthesis. These holes are sealed with medical grade PTFE tape and composite fillings after placement to prevent food trapping. Over time, fillings may wear out or fall off, requiring replacement. This is a minor issue and can be easily managed by a general dentist.

Loss of Prosthetic Tooth Anatomy Due to Wear

This occurs primarily in composite or acrylic prostheses due to normal ageing or excessive grinding. Ceramic materials retain their colour and shape longer but can cause faster or increased wear on opposing natural teeth or other prostheses.

Loss of anatomy and wear is considered to be part of the normal “wear and tear” of the prosthesis and often starts to be noticeable after 5-7 years.  It can however, happen much earlier in patients that are heavy grinders. Like most of the other complications, a nightguard does help reduce this. When it does eventually happen, if a refurbishment is not possible, a new prosthesis will be needed.

Understanding the Complications

Being aware of these potential complications allows patients to set realistic expectations and implement preventative measures to extend the longevity of their full-arch dental implants. Routine dental check-ups and strict daily use of a nightguard are crucial in minimising the risks associated with these technical issues. Should any complications arise, seeking prompt assistance from your experienced dental implant team will ensure the best possible resolution.