Dental Implant Fractures

Dental implants have been a preferred treatment option for rehabilitation of completely and partially edentulous patients. One of the most important complications is the fracture of a dental implant that has undergone osseointegration by which the prosthesis is adversely affected by the loss of the supporting tissue. Although the success rate of this procedure is >95%, at times it was also reported with fractures at rare incidence.

Implant design and manufacturing defects

Nonpassive fit of the prosthetic framework

Physiologic or biomechanical overload.

Other possible causes of fracture can also include failure in the production and design of dental implants, bruxism or large occlusal forces, superstructure design, implant localization, implant diameter, fatigue, and bone resorption around the implant. The risk of fracture also increases with time.

Implants made of one-piece design are stronger than two-piece conventional titanium implants. Here is one example of a CeraRoot fracture and how it was solved without removing the implant completely:

Ceramic dental implant fractures

Titanium dental implant fractures

Implant removal is also indicated when the implant fractures. Titanium Dental implants are made of commercially pure titanium, which ranges from Grade 1 to 4, in increasing degree of strength. All are capable of withstanding biting forces over the long term once they are integrated with bone. However, if oral hygiene is poor, implants are susceptible to peri-implantitis, ie inflammation of the bone around the implant, just as natural teeth are susceptible to periodontitis. This results in bone loss originating from the part of the implant which connects to the crown. This is the part of the implant that is weakest mechanically because it is hollowed out to accommodate the abutment screw. Without external support from the bone coupled with lateral forces transmitted by the abutment screw may cause the implant to fracture.

Implant removal is also indicated when the implant fractures. Dental implants are made of commercially pure titanium, which ranges from Grade 1 to 4, in increasing degree of strength. All are capable of withstanding biting forces over the long term once they are integrated with bone. However, if oral hygiene is poor, implants are susceptible to peri-implantitis, ie inflammation of the bone around the implant, just as natural teeth are susceptible to periodontitis. This results in bone loss originating from the part of the implant which connects to the crown. This is the part of the implant that is weakest mechanically because it is hollowed out to accommodate the abutment screw. Without external support from the bone coupled with lateral forces transmitted by the abutment screw may cause the implant to fracture.

A fractured implant is even more difficult to remove because unlike the earlier example, there is no exposed implant sticking out for the trephine to go over. Bone has to be trimmed to expose the retained part of the broken implant before the trephine can be applied. Furthermore, the broken end does not have an engaging part for a driver to be connected for reversion and can only be drilled and elevated like a broken tooth.

As the implant removal entails removing a lot of bone, due consideration must be given to whether there is sufficient bone remaining for a replacement implant. When the bone is insufficient, multiple stages of bone and soft tissue grafting may be needed over a period of several months or even more than a year. Reconstructive surgery is not always an exact science and revisions to initial surgeries may be needed to create an aesthetic result. The alternative is to accept the compromised position of the implants and improve on the aesthetics and function by minor gingival plastic surgical procedures