Dental implants replace the roots of teeth and can be used to anchor a single dental crown or crowns, a bridge or a denture. Dental implants are usually screw shaped and made from pure titanium metal. This is used because it fuses directly to bone, a process called Osseointegration. Implants are typically 3-6 mm diameter and some 7-18 mm in length. There are commonly three parts to what is described as an implant; the implant fixture itself which is inserted directly into bone, the abutment an interconnecting part crossing the gum and connecting the implant to the overlying crown or denture made from titanium, gold or ceramic.
Dental implants were first used to treat patients in their current form some forty years ago. Per Ingvar Brånemark a Swedish Professor discovered that the metal titanium fused (osseointegrated) directly to bone in studies of blood circulation.
The dental implant system and clinical techniques he developed became widely used from the early 1980’s.
Dental Implant Advantages
There are benefits from dental implant advantages. A dental implant may be placed at the same time a tooth is removed or sometime after extraction. Implants and their crowns can often be placed in the ideal position (subject to the availability of suitable bone), closing spaces, matching natural teeth and creating the optimal aesthetics. Under some circumstances and the subject of careful clinical assessment an implant can be placed, and the overlying crown or denture placed immediately or very soon thereafter. However, under some circumstances with poor bone quality for example it can be prudent to wait for healing and osseointegration to take place using a temporary crown or denture in the interim.
A skilled and experienced clinical professional will be able to assess the patient on their individual circumstances and specialist advice are important.
Natural teeth suffer from disease; tooth decay (caries) and gum disease (gingivitis or periodontitis). Implants do not suffer from these conditions. They have the longest lifetime of implanted medical devices and current designs are having reported success rates in excess of forty years. Longevity is dependent on individual clinical cases and a specialist will be able to advise on risk factors. Some implant components and prosthetics may require replacement due to wear and tear and mechanical factors.
Dental Implant Safety
You may be keen to know about dental implant safety and success rates. Dental implants are amongst the safest and most successful implantable medical device. Implant is usually a minimally invasive surgical technique administered with a local anaesthetic. The success of dental implants is typically in the upper 90’s%. Those implants that fail may do so due to inadvertent loading or risk factors such as poor bone, smoking and surgical factors. Failure may happen without infection or the patient being aware and result in implant mobility. Successful replacement is commonly achievable.
There is very little published scientific evidence of allergy to titanium. The material demonstrates a high degree of biocompatibility. Careful treatment planning is important as with any medical procedure and it is strongly recommended that patients consult experienced clinicians and specialists for advice and treatment.
Dental Implant Costs
Implant treatment is relatively expensive. This is because in addition to the clinicians surgical and treatment costs there are laboratory costs as well as the cost of the implant components themselves. The upfront cost of dental implant treatment should be taken in context with a comparison with the replacement costs of traditional treatment like bridges and dentures over comparable periods of time. A specialist will be able to offer advice on individual circumstances.
Overview of Dental Implants Applications
There are many dental implant applications, as they can be used to help many patients. There are few restrictions or contraindications. In general, dental implants are not placed in children or teenagers who are typically still growing. A denture or simple bridge may be used to maintain a space created by loss of a tooth or teeth as the result of an accident or for orthodontic reasons. When the patient has reached adulthood implants may be placed. There are no contraindications to implant placement in elderly patients for whom placement of two implants to support a denture may prove a considerable benefit in eating.
Patients with a medical history should always consult their clinician prior to considering implant treatment although again there are relatively few contraindications. One of the most important factors is having sufficient bone of the right quality and quantity in the appropriate part of the mouth to support implants. Patients with insufficient bone may still be treated with grafts but this can result in more expense, time and relative discomfort.
Dental Implant Crowns
A dental crown supported by a dental implant is the simplest form of treatment. The implant is commonly used as a tooth replacement, for a tooth that has been lost by trauma, decay or fracture.
Dental Implant Dentures
In simple terms a bridge only replaces the crowns of the teeth. When teeth are lost the gum and bone will recede (shrink back) over time as it is no longer needed to support teeth. In order to replace missing teeth with bone loss, a prosthesis is needed which also has a proportion of artificial gums usually made of pink acrylic or porcelain. Implant based dentures can be made. These may be held in by press-stud type or bar attachments making them removable for cleaning. Alternatively, small hidden screws may fix the dental denture in place. These can be readily removed by a clinician for cleaning and maintenance.
Dental Implant Diagnosis
The dental implant procedure commonly begins with the patients being referred by their general dentist to a specialist implantologist. It is also common for a general dentist to work with the specialist in providing the crown and bridgework on top of the implants.
Implant diagnosis typically includes a careful consultation with history and radiographic examination. Note is often made of the patient’s medical history.
Dental Implant Preparation
Dental implant preparation procedures may be carried out prior to actual implant placement. These include production of model’s stents and guides to assist the surgeon in the correct placement of the dental implants.
Dental Implant Surgery
Dental implant surgery itself is most commonly carried out under local anaesthetic. Sedation may be available for patients in an oral or intravenous form although this varies. The surgery carried out is most commonly a minor surgical procedure entailing extraction of teeth is necessary, lifting back the gum tissue and the placement of the implant itself with a small amount of drilling. Sutures are commonly placed and the patient may expect a small amount of discomfort and swelling following placement.
Dental Implant Final Restoration
Implants may be placed in two surgical stages; the first being implant placement where the implant is buried in the bone beneath the gum, the second stage is where the implant is uncovered and an abutment connection made. Alternatively, a single stage procedure is where the healing abutment that can be seen immediately in the mouth following implant placement. After the healing period, this abutment is removed and the impression moulds taken by the dentist. A laboratory will commonly make the final fitments to be placed at the final stage.
Dental Implant Healing/Osseointegration
After a dental implant is placed, the healing will happen quite quickly for the soft tissues; within a matter of week or two. The healing of bone around a dental implant is termed osseointegration and can be likened to a healing bone fracture. It typically takes some 6 to 8 weeks although re-modelling and ongoing changes can take place for a year or more. Like a bony fracture it is important to immobilise the dental implant and prevent inadvertent loading or chewing which can cause mobility and early implant failure.
Dr. Yi (Terry) Pu
B.D.Sc (Hons), GradDip (Dental Implantology)