What is a Dental Implant?
A dental implant is an artificial device (prosthesis) used to replace missing teeth. It is based on a titanium screw fixed into the jawbone. The screw acts as an artificial tooth root to support a crown, bridge, or a denture.
A single implant is needed when only one tooth is missing and has to be replaced.
Parts of a Single Implant
A single implant consists of 3 parts:
- Implant—the titanium screw which serves as an artificial tooth root
- Abutment—a small post used to connect an artificial tooth to the implant
- Crown—the artificial tooth
How do they work?
Single implants work by making a bond with the jawbone, a phenomenon medically known as ‘osseointegration’. Development of the bond between the titanium surface of the implant and bone cells locks the implant into the jawbone.
Single Implants vs. Fixed Bridges
Single implants have the following advantages over conventional fixed bridges:
- Better aesthetics
- Function more like natural teeth
- Easier maintenance of oral hygiene
- No need of grinding the adjacent healthy teeth to provide support for the replacement tooth, eg. in crown and bridge work
- No bone resorption or “loss”. The jawbone remains intact because of osseointegration of the implant into the jawbone. This holds bone around the implant which would otherwise be lost over time following removal of a tooth
- Longer lifespan of single implants when compared to fixed bridges
Placement of Single Implants
Surgery for placement of single implants is carried out over different stages, depending on the initial stability or “torque” of the implant and possible need for reconstruction of the tissue and bone around the implant using grafts.
Initially, an incision is made in the gum tissue and a soft tissue flap is raised to expose the jawbone where the single implant is to be placed. The bone is drilled to create a space for the single implant.
1 stage placement: this can occur if the primary stability or “torque” of the implant is good. A healing cap/abutment is placed which sits just above the gum and allows the tissue to mature around it, preparing the site to accept the crown
2 stage placement: this occurs if the primary stability or “torque” of the implant is less than desired (softer bone) or if extensive grafting is required around the implant
*1st of 2 stages – A coverscrew is placed on the implant and then covered over with gum tissue. This allows the implant to heal undisturbed for 3-4 months
*2nd of 2 stages – At the 3-4 month mark, a small local anaesthetic procedure uncovers the implant and a healing cap is placed (as described in 1 stage procedure above). This is left to heal for approximately 2 weeks before impressions are taken.
Single implants require 3 to 4 months without forces applied, ie. no direct chewing on the site, no chewing of hard foods on either side (as this flexes the jaw) to allow healing and integration. This ensures firm anchorage to the jawbone. Early function can result in soft tissue instead of bone growing around the implant surface which causes mobility and failure of the implant.
Once the implant has been checked and deemed “osseointegrated” and the tissues surrounding the healing cap are stable, an impression (mould) of the implant in relation to the surrounding teeth is taken and sent to the lab. The lab prepares the “abutment” which serves to connect the crown to the implant and the crown (the prosthetic tooth). This is then screwed into the implant and the access hole sealed.
Screw retained crowns have the flexibility of being able to be removed in case of need for repairs, change in colour of adjacent teeth (if whitened), or need to add teeth to make a bridge (if an adjacent tooth is lost later).
So, how long does the whole process take?
The average time required for the complete process is usually 5 to 8 months. It can be longer, if additional surgical procedures such as bone grafting, gingival grafting, tooth extraction or sinus lift are required initially for proper placement of single implants.
In cases where there is need to remove a broken down or failing tooth prior to placement of the implant, there may be a period of 4-6 months prior to implant placement to allow bone to grow back into the socket left after removal of the tooth.
If the tooth extraction is complicated or if there is infection associated with the tooth that has resulted in significant loss of bone at the site, there may need to be some synthetic bone graft used at the time of extraction. This may also be the case if the tooth has been missing for some time and there has been gradual bone loss at the site, especially near the sinuses.
Some sites, eg. some front teeth and back teeth (molars), have sufficient bone above and around the socket to allow immediate placement of the implant at the time of extraction. This saves 4-6 months of healing time, meaning your final restoration is inserted sooner and your function or aesthetics restored sooner. For front teeth or premolars, you could potentially have a replacement fixed crown inserted on the same day as the extraction and implant preventing embarrassing gaps in your smile.
This will be assessed during your consultation and after reviewing your 3D scan (cone beam CT) of the site.
Dr Jaclyn Wong will provide you with a customised treatment plan that suits your needs and clearly outline the stages, timing and costs involved at your consultation.
What do I need for the consultation?
It is ideal to have had a 3D scan (no older than 12 months old) PRIOR to your consultation to allow a complete and thorough treatment plan to be provided.
There are a number of centres across Melbourne that will provide this service for a small fee if you have no private health insurance or for no out of pocket expense if you do have private health insurance. Dr Wong also has arrangements with some radiology centres in Melbourne to provide this 3D scan bulk billed through Medicare. Please enquire about this when requesting an appointment either by phone or via our “Contact Us” page.
Risk factors for failure of Single Implants
Placement of single implants is considered with caution, due to higher risk of failure, in persons with:
- Poor oral hygiene
- Poor compliance with post implant placement instructions, ie. early chewing on the implant causing failed integration
- A habit of teeth grinding or clenching
- Periodontal disease and infection in adjacent teeth
- Heavy smokers
- Diabetics that are poorly controlled
Research has proven that single implants have a success rate of 93 to 98%, provided that they are:
- Well-planned by an expert in the field
- Well-integrated into the bone
- Properly taken care of by patients (routine check-ups, brushing and flossing, avoiding early function on the implant)
- Patient is not a high risk for single implant failure