Concept Dental

Specialised Dental Treatment

Crown & Bridge

• General Information- Crowns
• What are the benefits for me?
• What risks and limitations are involved?
• How long do crowns last?
• Guarantee?
• Crowns Example
• Anterior Crown
• Bridgework

Implants

• General Information- Implants
• Single Tooth Implant Supported Molar Replacement
• Hybrid Bridge for the Mandible
• Implant Supported Over Denture

Full-mouth reconstruction

• Extensive Rehabilitations

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Crowns

What is a crown?

• Essentially it is a thimble that is cemented over a tooth to improve its strength, shape and appearance
• There are various types of crowns which are made from different materials, such as precious metal alloys, ceramics or a combination of these materials.

What are the benefits for me?

• Stengthens weakened, brittle teeth!
• Crowns improve the structural durability and reduces the risks of complications of heavily restored teeth e.g Cracking of fracture
• Enhances appearance by changing colour, shape and alignment

What risks and limitations are involved?

• Crown treatment is an irreversible procedure procedure
• 3-6% of the crowned teeth may require root canal therapy as a result of the cumulative trauma on the internal living structure (the “nerve”)
• Approximately 30% of crowns fail because of decay at the joins (junction between crown and tooth)

How long do crowns last?

• Literature review suggests that the average life span of crowns is around 12 – 15 years. Further evidence suggest that there is a 90% survival over 10 years and approximately 50% over 20 years. Most crowns can be retreated.
• Failure is usually divided into biological (decay, gum or nerve problems) and mechanical (uncementation, fracture of porcelain and loosening of crowns)

Guarantee?

• Mechanical aspects are under the control of the clinician. At this practice crowns are guaranteed against mechanical failure for a period of three years.
• Biological failures cannot be included as they are individual patient factors e.g. “Nerve” problems, gum recession or dental decay around the joins. However, every effort will be taken to minimize these possibilities through clinical excellence and good preventative program.

Crowns Example

A young woman in her early 20’s presented with an abscess on her upper left lateral incisor. The prognosis for re-treatment of the failed root canal therapy was extremely poor and the tooth needed to be extracted.

A temporary removable partial denture was placed to allow bone healing following which a single implant fixture was inserted. The picture shows the healing abutment stage.

Finally an all ceramic crown was placed on a suitable abutment connection. The implant supported crown looks feels and functions like a natural tooth.

The post operative film shows a titanium fixture well integrated into the bone which well maintained should have a good long term prognosis.

Anterior Crown

A young lady in her late twenties presented with heavily restored incisors showing poor aesthetics.

The solution most appropriate for her needs was bleaching of her teeth followed by all ceramic crowns on the four incisor teeth.

With ceramics it was possible not only to control the colour of the teeth but also improve on the shape and character to give a pleasing result.

Bridgework

After orthodontics

Minimal enamel preparation & retraction cord in place

A clustral view of bridges in place

Farewell View

General Information- Implants

Dental implants have been part of Dentistry for over 50 years. Unfortunately, the early designs and surgical techniques had a high failure rate. However Swedish and Swiss research team in the late 1960’s and 70’s respectively developed implant designs and a surgical techniques that led to the current state of the art implants that are being used in the millions today.

Osseointegration is the term used to describe the fact that an implant has been biologically accepted by the bone. The implant is rigidly fixed in the bone enabling it to be used as an abutment for a dental restoration.

Implants are not the same as natural teeth.

They do not stand up to bite forces as well as natural teeth nor do they move physiologically in the bone like natural teeth. This is why, (with some exceptions), implants and natural teeth should not be connected with fixed bridges. Whenever possible, the natural teeth around the implants should bear the majority of the load (bite forces) in the area. This means that sometimes, natural teeth in the vicinity of the implants may need a restoration (crown), in order to stabilize the bite.

Implant Planning and Surgery

The Implant Surgeon places the implant in the jaw bone utilizing special drills. The placement of the implants is critical and the location is decided upon after numerous diagnostic and laboratory steps are taken, x-rays, dental study casts, trial placement of teeth on laboratory models, CT Scans and surgical templates have been obtained. Dental implants can only be placed where there is enough height and thickness of the bone. When there is not sufficient bone, bone grafts need to be done.

It is possible that an Implant Treatment Plan may have to be modified, altered, or discarded completely as a result of the following:

• Poor quality of bone
• Inadequate height and width of bone
• Inability to place an adequate number of implants in the correct location
• Failure of one or more implants to osseointegrate

Any Implant Treatment Plan that has to be modified before, during or after implant placement will be discussed with the patient. The fees quoted for the implant treatment will change accordingly. The fees may be increased or decreased.

Patients should be flexible in their vision of how their dental treatment is going to end up looking and feeling due to the fact that some implant treatments may change in midstream.

Ideally, all implants should be placed in such a fashion that all bite forces are along the axis (the length) of the implants. This may not always be possible to accomplish in some areas of the mouth. As a result implants in the front of the mouth (canine to canine region), are placed primarily for aesthetics and compromises may be needed with respect to functional force management (bite forces). Implants in the back of the mouth (premolars and molars) are placed primarily for function and at times a compromise may be needed with respect to aesthetics.

Single Tooth Implant Supported Molar Replacement

Patient presented with a missing molar.

The adjacent teeth are showing signs of early stage bite collapse. A single tooth implant supported crown is the treatment of choice to prevent further movement and complications.

Single tooth implant abutment has been placed onto a fixture which was surgically inserted into the bone 3 months ago. The abutment will be used to support the crown.

Post operative film shows the implant fixture fully integrated into the bone supporting a metal ceramic crown.

Post operative clinical view of molar implant supported crown. The artificial tooth will now function exactly like a natural tooth and well maintained will give a good long term prognosis.

Hybrid Bridge for the Mandible

Progressive bone resorbtion over years leading to denture mobility and loss of function

Radiographic film of mandibular bone resorbtion

Implant abutments placed on implant fixtures 3-4 months following surgery. These will be used to support the final bridge

Radiographic film showing well integrated fixtures supporting the gold alloy framework of the fixed bridge

Final bridge in place permanently attached to the implants restoring normal function

Indication

• Replacement of full lower complete dentures
• Good general health

Advantages

• Restores the look, feel and function similar to natural teeth
• Tends to preserve the remaining bone
• Improves psychological self esteem, of being truly rehabilitated

Disadvantages

• Requires surgery for placement of fixtures
• Generally takes 6 months treatment time
• Significant financial investment required

Risk

• Small percentage of failures of fixtures
• Small percentage of componentary failure (2.7%)
• Need for ongoing maintenance

Longevity

• Present indications are that the probability of the fixtures lasting 20+ years in healthy patients is in the 90% percentile
• Composite teeth and acrylics on the bridge may need to be replaced every 7-12 years due to wear and tear.

Summary

From a purely biologic and functional perspective the hybrid lower Implant supported bridge is the best method of restoring and maintaining oral function where lower dentures are worn. Implant fixtures stimulate the supporting bone more naturally. This tends to preserve jaw bone density and height. Implants substantially improve the quality of life in the aging edentulous population.

Implant Supported Over Denture

An elderly patient presented with failing lower telescopic crowns. These teeth were untreatable and they were removed and a complete lower denture placed. After several months the patient found adaptation to the new situation very difficult due to denture movement and discomfort during eating.

After consideration of the various options two implant fixtures were placed in the lower jaw. These were allowed to integrate for 3 months.

Abutments were placed on the implant fixtures. The lower denture was then relined during which snap fitting female attachments incorporated into the denture.

The problem of mobility was eliminated and the lower denture provided stability and security during function.

Full-mouth reconstruction

Extensive Rehabilitations

The practice specializes in full mouth reconstructions. Rehabilitating broken down dentition in a comprehensive and systematic fashion, particularly in challenging cases is one of our greatest strengths. This may encompass a multi-disciplinary approach with other dental specialists or be accomplished exclusively in our premises, dependent on the individual needs of the patient.

As a result, with careful planning, modern techniques, and meticulous execution, orally rehabilitated patients are able once again to achieve the look, feel and function similar to that of natural teeth.

Pre-op frontal view

Mr L. a sixty year-old gentleman was concerned about the level of breakdown of his teeth and the ongoing problems of patchwork dentistry. His principle concerns were the look of his teeth, problems with his fillings and the inability to chew adequately. Due to the extensive nature of the breakdown a reconstruction using tooth supported crown and bridgework was the treatment of choice.

Post op frontal view

Although some lamination fillings are still required on his lower canines Mr L. was delighted with the end result, (and so was his wife).

He has now been placed on a maintenance, preventive programme to maximize the longevity of the work placed in his mouth.