Dental implants: How long do the implants last?

The implants are manufactured in exceptionally strong materials and they are designed to withstand calculated masticatory forces with an ample margin of security. Nonetheless, for as rare as it may be, it is possible for implants to break, but besides this mechanical accident, the problems associated to dental implants are more often to blame on the breaking of the tissues surrounding them. There are three conditions that can lead to the loss of tissue surrounding the implant: the local conditions, the systemic conditions, implant overload. Let's take a detailed look at each condition.

1: local conditions. Bacteria accumulates around the implant just as it would around a natural tooth. If the bacteria are allowed to stay in this position, the gums will undergo inflammation and eventually provoke degradation of the bone supporting the tooth. This process has a name, it is the periodontal pathology, which is referred to in this manner because it develops around the tooth (from the Greek word peri, around). The same process also develops around an implant, if bacterial plaque accumulates without being removed by a proper dental hygiene. The implant is easier to clean than the tooth it replaces, but conditions such as osteoporosis, collagenous pathologies, uncontrolled diabetes, frequent use of alcohol or tobacco, drug use or any debilitating illness are able to inhibit the body from repairing itself correctly. In presence of these conditions implant duration rate is reduced; if dental hygiene is done rapidly or with negligence, damage to the supporting tissue is quite certain. Other local damage can derive from an incorrect use of cleaning tools or by the contact with a variety of irritating agents, whether mechanical, chemical or thermal;

2:systemic conditions.  Any systemic condition that impairs the body from repairing bones or other tissues is able to provoke implant support depletion.

3: overload. Every time that a structure is overloaded, some of its parts give way. There are loads which re-enter into physiological tolerance of the tissues which support either a tooth or an implant, and in this case it is not only the tissues that  perfectly sustain the load, but this actually stimulates the supporting bone to further develop itself and integrally preserve itself around the tooth or the implant. The teeth take part in activities such as eating, swallowing and speaking under various degrees of force: these forces are generally physiological in nature, and in absence of anomalies they stimulate bone mass formation. During periods of extreme muscular activity, for example in instances of weight lifting, the majority of people clench their teeth with notable force; this force can by long surpass many times the total force applied on a tooth while eating. Though being quite intense, these forces are exerted for only short periods of time, therefore the probability of their causing damage is quite meagre: these forces may surpass physiological loads in size, but generally not in duration. Even emotional stress can provoke damage not only to tissues supporting the tooth, but also to those supporting the implant. This is the case of bruxism, the involuntary grinding of teeth. Emotional stress can also alter the body chemistry thereby provoking a systemic condition that weakens support tissues rendering them more likely to break. Another case is represented by chewing gum, whose use can transform a physiological load simply by increasing the amount of time during which the forces are exerted, going from the average of 40 minutes per meal to 12-14 hours daily. To sum everything up, this means that if held in good hygienic conditions in a healthy body that is not stress-devastated, an implant can last without problems for many, many years. Obviously not everybody satisfies all of these conditions always, nonetheless according to the specialised literature the data in retrospect of total implant success is  95% in 5 years, this means that 95% of all inserted implants have lasted for a period of at least 5 years without any problems, and that only 5% of the implants needed to be removed before the 5 year limit. A professionally prepared dentist who has accumulated a lot of experience during the years in his field will reach the point of installing implants which last for at least 15 years, even if the data of the average implant life seems to be, according to some authors, superior to 20 years. Attention: it is impossible to know beforehand the duration of a specific implant; the indicated figures refer to the current scientific literature which under no circumstances represent a surety.

last update: 21 January 2008