January 5 2022
Written by Dr. Justin Seaman
Can my body reject Dental Implants? This is a question that more than one patient has asked over the years. The simple short answer is yes, but highly unlikely; the longer more detailed answer is multifaceted, individually unique, and not completely understood. Read on as we explain more.
Dental Implants Have a High Success Rate
What is known is that millions of titanium implants have been placed over the last 40 years and the success rate is well documented in the high 90th percentile. Dental implants are composed of the same metals that are placed into other areas of the body when joint replacement is needed or the fixation (stabilization) of fractured bones are required. Titanium and its alloys are the majority of all the dental and orthopedic implants placed around the world today. It is favored for its properties that allow predictable integration in the patient, excellent strength, low elastic modulus, corrosion resistance, lack of tissue toxicity, and very low incidence of allergic reactions. Regardless of the shortcomings of the material, dental implants have truly provided wonderful treatment outcomes in previously difficult or impossible to restore cases.
Dental Implants Are Designed and Placed In A Way That Prevent Patients Bodies From Rejecting Dental Implants
When a dental implant is placed into the jaw bone, it is covered in titanium dioxide, which protects the implant from being reactive with surrounding tissues. This protective layer is spontaneously created the moment the titanium dental implant surface is exposed to air during the production process. This very thin protective layer can be altered through touch, so that much care and attention is given to the implant during the insertion process. We are very careful in the handling of the implant so that the surface is not touched, altered, or contaminated prior to the final placement in the bone. However, it is now being discovered that the surface can be altered during the placement process as the implant is being torqued into its final position, tribocorrosion.
How Are Dental Implants Susceptible to Contamination and Failure?
Tribocorrosion is defined as the science of surface transformations resulting from the interaction of mechanical loading and chemical/electrochemical reactions that occur between various elements exposed to a corrosive environment. The rubbing of the implant surface against the bone (mechanical loading) can create an alteration of the implant surface and expose some of the underlying titanium material. These exposed surfaces are more susceptible to interactions with surrounding tissue and more likely to shed some titanium nanoparticles, which may increase the chances of having a reaction to the material.
Mechanical, bacterial, or chemical factors can cause degradation of titanium dental implants, which increase the shedding of titanium nanoparticles into the surrounding tissue. These nanoparticles can stay localized in the surrounding tissue or can be carried away in the plasma and be circulated throughout the body.
- Mechanical: direct contact with implant surface, connection between dental implant and abutment, high torque during placement of implant; all of which can expose titanium that does not have a dioxide layer and allow a more reactive surface to be exposed.
- Bacterial: exposed titanium can have bacteria growing on the surface, creating a biofilm, which allows continuous implant surface exposure to unfavorable conditions.
- Chemical: oral microbacteria change dietary sugars through fermentation into organic acids which lower the pH of the environment around the implant. Lower pH, more acidic environments, and higher concentrations of bacteria by-products can cause erosion of implant surfaces and loss of bone around implants.
Although it is extremely rare for a patient to have a true titanium allergy, believed to be much less than 1% of the general population, implants can become compromised, infected, and ultimately fail if not properly maintained.
Proper Maintenance Prevents Dental implant Failure
Implants are no different than teeth in the fact that they need to be properly cared for at regularly timed intervals. Ideally, implants should be cleaned multiple times a day (just like a natural tooth) and be evaluated by a dentist a couple of times a year (semi-annual checkups). The human mouth is the perfect environment for growing bacteria: dark, warm, moist, with an endless supply of food.
While it is impossible to accurately determine how many bacteria are present inside our mouth at any given time, estimates range from a few billion to as high as 20 billion. On top of that mind-blowing number, consider that researchers have also determined that there are 500 to 650 different species also present. It is no wonder why that the primary reason a dental implant fails is infection.
Daily cleanings at home and regular cleanings by your dentist will help minimize the likelihood that your implant surface becomes contaminated and eventually infected. Regular visits to the dentist will help protect your implant investment on multiple levels. Besides providing a thorough cleaning, the dentist will check your occlusion or “bite” to ensure that the implant and teeth are not hitting with too much force.
Natural teeth have an apparatus called the periodontal ligament (PDL), which acts like a shock absorber and Velcro all at once. The PDL surrounds the root of the tooth and is attached from the bone to the root of the tooth. When teeth come together, the PDL can be compressed, acting as a shock absorber. If force is placed on a tooth for too long, it can shift through slow changes in the bone or root. This is how teeth are slowly moved by orthodontics. When too much force is placed on a tooth, damage can occur to the PDL, root, tooth, or bone. Dental implants do not have a PDL and cannot be moved like a natural tooth. If an implant has too much force placed on it from being out of occlusion (i.e. in a bad bite), the tooth, implant, or bone can break. Normally, people can tell that their implant is not in proper occlusion since the opposing tooth will have typically be natural and have a PDL which would become tender or inflamed if in traumatic occlusion. Regardless we typically recommend having a nightguard fabricated to help protect your teeth while sleeping since we can apply incredible amounts of bite force while we are asleep. Nightguards are dentist-made occlusal orthotics or splints that will cover all of your teeth and spread out the nightly forces placed during nocturnal clenching.
Despite all of the potential issues that face dental implants, they are very simple to have placed, restored, and maintained. This is especially true if you take care of them in a similar fashion to your current teeth.
Lastly, if you are one of the rare few who have an allergy to titanium you can still have a dental restoration placed on a different type of implant, one made out of zirconium. While these implants are not as common as titanium, they are a viable option and improving all the time.
At Lighthouse Oral and Maxillofacial Surgery, we will take our time to discuss all of these potential issues while creating the individualized plan designed just for you and your circumstances. Contact our office to schedule a consultation at (713) 790-1995.