As this is a process in expert hands, the long-term success rate of dental implants is 95%. Logically, this success rate is achieved by correctly selecting the patient. However, a small percentage of failures does exist even when all of the protocols are rigorously followed.
Remember that these problems are not due to "rejection" as this does not occur when quality implants are fitted.
Failures can be divided into early failures and late ones. The causes related to them are explained as follows.
Early failures occur in the first few months before fitting the prostheses, and can be due to inadequate bone quality; in fact, more failures occur in the upper jaw than in the lower jaw because the bone tends to be spongier, less compact and of poorer queality in general.
Other influencing factors are the heat caused by drilling before fitting the implant, meaning good irrigation is essential after each drilling procedure and fitting the dental implant, and of coursecourse working at the right number of revolutions for the type of work in question. Working at high speeds can cause overheating and cause necrosis to the bone, meaning the dental implant will not take.
Applying too much pressure while drilling can also damage the bone, hindering correct regeneration. The drill bits must be perfectly sharp and be thrown away after each use.
Therefore, it is necessary to respect the bone biology to ensure correct healing.
Infection can also cause the implant to fail. It is essential to work with completely sterile material and under aseptic conditions.
If we apply prostheses to the dental implants too soon, this can also cause them to fail.
Once the prosthesis has been fitted, if this does not fit the implant perfectly it can cause stress points. The fit must be perfect without any type of stress, otherwise failure is inevitable.
The patient’s type of bite is important, as people who clench or grind their teeth at night (bruxist) can fracture implants or cause cracks due to excess pressure.
The patient’s bit must be correctly balanced even if they do not grind their teeth, as chewing is a dynamic process and it is important to reach a balance in all of the different movements. There are types of bites that may mean dental implants are not advisable.