Treatment of tooth loss with dental implants is today a routine advanced specialty procedure in Dentistry. The Dental Services has considerable expertise in dental implants which allows the management and oral rehabilitation of patients with varying degrees of tooth loss. The Departments of Restorative Dentistry and Oral & Maxillofacial Surgery has the cumulative experience of treating patients with dental implants since 1987.

Whereas previously, patients had been restricted to wearing dentures, the use of implants integrated and biologically compatible with the jaw bones now allows for tremendous improvements in our ability to treat patients with missing teeth and achieve rehabilitation of oral function.

Osseointegrated titanium implant with artificial crown attached via a transmucosal abutment

Patient Assessment for Suitability for Dental Implants

All patients are first assessed clinically for suitability for implant supported oral rehabilitation. The limiting factor in the majority of cases is the presence of sufficient quantity and quality of bone in the residual ridges. Patients are examined for sufficient height and width of available bone to accommodate the implant fixture. Diagnostic imaging with x-rays and sometimes even CT scans are performed. In cases where insufficient bone exists, grafting procedures can be an option.

Multiplanar-reformatted computerised tomography (CT) scan to determine bone available for implant placement during treatment planning phase
Multiple bucco-lingual slices following patient's dental arch	Sequential bucco-lingual views giving life-size view of bony ridge width and configuration

Very few medical conditions exclude patients from dental implants but implants are usually not recommended for heavy smokers and insulin-dependant diabetics.

Implant Surgery

Implant placement requires a 2-stage surgery. This may be performed under either local or general anaesthesia. Implants are placed in the jaw bone using precise instrumentation.

Surgical placement of titanium implant fixture

Over the long term, patients are required to undergo a strict protocol of meticulous home care and regular clinical recall visits for maintenance in order to maintain tissue health around the implants.

Prosthetic Rehabilitation

The exact position and angulation of the implants in the jaw bone is planned before surgery through consultation between the Prosthodontist and the Surgeon. The Prosthodontist will be responsible for planning and specifying the design of the final prosthesis and does this with the aid of study models of the jaws and a diagnostic set-up or wax-up. Surgical guides are then generated to precisely locate of the implants at Stage I surgery.

Varying degrees of tooth loss can be treated by prosthetic rehabilitation with implants. These range from the fully edentulous jaw to partially edentulous segments to single tooth replacements.

Fully Edentulous:

Complete dentures are notorious for their problems of retention and stability especially in patients with advanced ridge resorption. All this has changed with implant supported dentures allowing for much improved chewing function and oral comfort. Commonly, the lower complete denture is the more problematic and thus frequently indicated for implant supported rehabilitation.

OPG of atrophic mandible with five implant fixtures placed anterior to mental foramina

Clinical view of screw-retained "fixed-removable" implant denture of the same fully edentulous patient. The implant denture has provided this patient with greatly improved function

Partially Edentulous:

Even when the patient retains some teeth, some edentulous spans are too long for predictable treatment with conventional bridges. Also, when the edentulous span has no terminal abutment tooth at the end of the arch to support a bridge, a so-called free-end saddle situation is said to exist. Such patients have had no choice but to wear removable partial dentures in the past. Implant supported bridges are now possible in these situations.

Single Tooth:

Increasing numbers of patients are opting for the restoration of a single missing tooth with an implant supported crown. In conventional dental treatment, the teeth adjacent to the edentulous space would have to be deveneered and prepared to serve as abutments for a three-unit bridge. If these abutment teeth are intact and untouched by previous dental restorations then such a treatment modality would be very destructive of tooth structure. Again, before the advent of implants, there was very little choice – the patient wore a denture or had a 3-unit bridge fitted. Typical cases now suitable for implant therapy would be single tooth loss from trauma in the young adult patient or congenitally missing teeth.

Missing lower left 2nd premolar replaced with a single tooth implant restored with a crown

2-year recall radiograph of the same patient. Notice the close apposition of bone and lack of any peri-implant radiolucency. This is a typical picture after several years in function

Maxillo-Facial Defects:

Implants have been applied extra-orally in the cranio-facial region for the prosthetic replacement of missing ears, noses and eyes. In addition, they have proven to be a tremendous aid in the retention and stabilisation of intra-oral prostheses used in the rehabilitation of large acquired defects of the maxilla or mandible.

Prosthetic silicone ear retained by cranio-facial implants osseointegrated in the temporal bone of the skull

Contributed by A/Prof Keson Tan

back to Dental Centre