A dental implant is made up of a medical-grade titanium screw which is embedded into the jaw bone, to replicate a missing tooth’s root, which then carries either a dental crown, a dental bridge or a denture.
Figure 1: Dental Implant with a Crown
Figure 2: Implant-supported Bridge
Figure 3: Implant-retained Denture
This titanium screw, otherwise known as an implant fixture, will be surgically placed into the jaw bone under anaesthesia, and is usually left in site for at least 3 months in order to allow bone to fuse with it, in a process known as osseointegration. The success of the implant ultimately depends on how well the bone has fused to it, or the extent of the osseointegration.
A dental implant feels and looks most natural compared to other ways of replacing lost teeth. Implants are also useful to improve retention of complete dentures for patients who do not have any teeth left, especially the lower denture.
Why Titanium?
It all started with an accidental discovery when a Swedish physician, Professor Per-Ingvar Brånemark, was conducting an experiment where titanium optic chambers were inserted into rabbit bone to study the blood flow, and after a period of healing, these titanium inserts could not be removed, because the bone had fused to them! Realising he was onto something, Professor Brånemark then invented titanium screws which became the very first dental implants.
Prior to his discovery, it was a common perception in the medical (and dental) field that anything inserted into the bone will trigger a foreign body reaction and any retention of the object was purely mechanical (like a screw). Thus, the discovery of osseointegration with titanium implants lead to a significant breakthrough in tooth replacement technology.
Am I Suitable to Get Dental Implants?
Most people are suitable candidates for dental implants, with some exceptions.
The list below are contraindications for dental implants, meaning that if you have any of the below, implants would NOT be suitable for you:
- Have a medical condition such as a recent heart attack, stroke, cancer, or any other medical condition which requires deferment of dental treatment
- History of radiation therapy to the head and neck region for treatment of cancer, most commonly Nasopharyngeal cancer (NPC)
- History of bisphosphonates usage (such as Zometa, Fosamax) or other anti-resorptive medication to treat osteoporosis and bone metastases (such as Prolia, Xgeva)
- Poorly-controlled diabetes which will result in poor wound healing and higher implant failures
- Heavy smoker (more than 10 cigarettes a day) – twice the failure rate compared to non-smokers
- Have an active and poorly-controlled gum disease
- Bruxism or night tooth grinding, which will overload the implant and lead to early failure
Another key ingredient in ensuring implant success is to have sufficient bone thickness and bone height, as the implant fixture must be fully encased in bone in order to last.
Normally after an extraction, the alveolar bone which surrounds the tooth will start to shrink immediately, and after a while, what is left may not be enough to hold an implant. If inadequate bone volume is present, then an additional procedure known as bone grafting is required to “grow” more bone to house the implant fixture.
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What is Bone Grafting?
Bone grafting is a procedure where bone substitutes are placed next to the existing alveolar bone and the implant fixture, in order to promote new bone growth at these areas where bone is needed. The bone substitutes, otherwise known as bone graft materials, can be synthetic, or sterilised human donor bone, or derived from an animal source (commonly bovine). The bone graft is also usually covered by a collagen membrane, and stitches are placed over the grafted site. After a period of time (depending on the amount that is grafted as well as the type of graft used), new bone will be generated!
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Although it sounds quite terrifying, the procedure is done under local anaesthesia and has been described as being more comfortable than a wisdom tooth surgery. After the grafting procedure, some mild discomfort and swelling is expected, but these are easily managed with some painkillers.
What Can I Expect from Implant Surgery and How Long Does It Take before My Dental Implant is Done?
There are 4 methods of placing an implant, based on the timing of the procedure:
1. Immediate placement – done at the same visit as tooth extraction
2. Early placement – 4 to 8 weeks after tooth extraction
3. Delayed placement – 12 to 16 weeks post-extraction
4. Late placement – after more than 6 months
Immediate implants are only suitable for selected cases where tooth removal is followed immediately by placement of implant into the extraction socket. This reduces the waiting time; however, you will still not have a tooth yet as the implant needs to be left undisturbed under the gum for at least 3 months before a crown can be fabricated. Bone grafting is also almost certainly needed as the socket shape is never the same shape as the implant itself, and these voids will need to be filled up with graft material.
Early implant placement is done usually within 4 to 8 weeks of a tooth extraction. The reason for this is to allow for some soft tissue or gum healing to take place first before the implant surgery, to ensure sufficient gum will be present for better outcomes. Delayed placement, on the other hand, is done 12 to 16 weeks after tooth extraction to allow for both gum healing and partial bone healing before implant surgery.
Late placement is done at least 6 months after tooth extraction to allow for complete bone healing, but this protocol is less favoured today as evidence has shown that there will be significant bone loss if the implant surgery is delayed for so long, unless grafting had been done.
As mentioned earlier, after the implant fixture is placed into the jaw bone, there is normally a minimum waiting time of at least 3 months before the implant can be loaded – in other words, to have a tooth, bridge or denture connected to the implant fixture. Those requiring bone grafts have a longer waiting time, sometimes extending to 6-12 months, especially in cases with extensive grafting, in order to allow sufficient time for the implant site to “stabilise”.
Additionally, if your implant is submerged, you will need another additional visit to expose the implant via a minor gum surgery. This is known as 2-stage implant surgery. The advantage of submerging the implant is to allow better healing and stronger integration with the bone, and this is often indicated where bone quality is compromised or when significant grafting has been done. Once the implant is exposed and a healing abutment is placed, a short wait of 2 weeks is sufficient for the gums to heal before proceeding to the final restoration of the implant.
A submerged implant (with a cover screw) requires an additional minor gum surgery to expose the implant and have a healing abutment which allows the gums to heal around it.
Which protocol most suitable for your case, as well as whether a single or 2-stage surgery is appropriate, has to be determined by the dentist examining and treating you, as there are many factors to be considered. At times, the patient has to wear a temporary denture while waiting for their implants to be completed, especially if the front tooth is involved. But as the saying goes, “Good things come to those who wait,” and this is particularly true where implant surgery is concerned. Rushing the whole implant process may lead to compromised results and poorer long-term success.
A simplified flowchart illustrating the sequence of the implant procedure
How Long Can Dental Implant(s) Last?
Assuming there are no issues, you can expect a dental implant to survive and provide function for many years. The current literature reports a 90-95% success rate of implants at 10 years1, and 52-75% survival rate at 16 to 20 years.
1: Tricio J, Laohapand P, van Steenberghe D, Quirynen M, Naert I. Mechanical state assessment of the implant-bone continuum: A better understanding of the Periotest method. Int J Oral Maxillofac Implants. 1995;10:43–9.
How Do I Look After My Dental Implant?
Implants are usually very durable and are not susceptible to dental caries (tooth decay), but they still need to be cared for in order to last long.
The gums around the implant can get inflamed from plaque and tartar build-up, which can lead to peri-implant mucositis or the more serious peri-implantitis. Good hygiene practices such as brushing the gums with soft toothbrush, and flossing around the implants are essential to maintain the gum health, similar to how you would clean and floss your real teeth!
Inflammation of the gums and bone around the implant, caused by poor oral hygiene and active gum disease
Brushing underneath the implant crown or bridge is a must. Using an interdental brush allows you to clean difficult to reach areas which your toothbrush cannot get access to.
Excessive bite forces on the implant should also be avoided, as the parts such as the internal screw securing the crown to the implant may fracture, or even the crown itself. Although some of these parts can be replaced easily (at additional cost, of course), sometimes if the damage is severe, the whole implant fixture may be rendered non-useable, and may need to be removed via explantation. Hence, it is always better to err on the side of caution and avoid biting on hard crunchy foods such as nuts, ice cubes, crab shells etc.
X-Ray showing a fractured implant fixture caused by excessive bite forces – this implant is no longer useable and will either be buried or removed completely via explantation
If you have been told that you grind or clench your teeth at night (nocturnal bruxism), then wearing a nightguard when you sleep is also essential to ensure the longevity of the implant, as studies have shown that bite forces up to 6 times the normal daytime bite force can be generated and the implant may fail when subjected to such disproportionate forces. A nightguard will also protect the rest of your teeth from wear and damage caused by excessive grinding.
A customised nightguard
Can I Use Medisave for My Dental Implant(s)?
Since placement of implant is considered a surgical procedure, your Medisave funds can be utilised to partially offset the total cost of the implant, as well as any bone graft procedures required. You can also utilise your spouse’s, parent’s, child’s or sibling’s Medisave account, with their consent. The total costs involved will be advised by the dentist.
