Preoperative Assessment

This patient's main complaint is that his teeth are very worn down.

Due the deep overbite there is no possibility for his dentist to build the teeth up again without the changing the occlusion first.

This treatment modality requires a combination of orthognathic surgery orthodontics, and restorative treatments.

Presurgical Orthodontic Treatment

Fixed orthodontic treatment is used to level and align the teeth prior to surgery.

Orthodontic treatment continues following surgery to provide final tooth positions in order to assist the restorative dentist.

[Orthodontist: Alison Murray]

Lateral Cephs Showing Pre- and Post- Surgical positions

Lateral Ceph on the left shows the tooth and mandibular position prior to orthodontic treatment.

Lateral Ceph on the right shows the new tooth and mandibular positions after the orthodontic alignment and surgery. Notice the improved facial profile.

[Maxillofacial Surgeon: Keith Jones]

Diagnostic restorations.

The maxillary incisors are mocked up in composite for assessment of aesthetics and speech. In the mandible, crown lengthening has exposed more tooth substance coronally.

This improves the appearance of the lower incisors, and provides a more aesthetic gingival profile.

Crown Preparation X6.7

A Zekrya gingival retractor and protector [Maillefer] are used to reflect the gingivae from the sulcus. This allows protection of the gingival tissues during the preparation of the margins.

Trauma to gingivae results in scarring of tissues and contributes to gingival recession. Notice this sympathetic approach has avoided gingival haemorrhaging.

This will improve the accuracy and quality of the working impression, and reduce recession by avoiding scarring of the gingivae.

Final Preparations X4.0

A dual cord technique is used to retract the gingivae and left for 5 minutes prior to making an impression. The second layer of retraction cord is not packed into the gingival sulcus. It is merely placed lightly to displace the gingival tissues.

Careful management of the soft tissues at this stage will result in a lack of gingival bleeding, an improved impression, and provide a better post operative result.

Crown Margins X24

The high powered magnification and illumination offered by the microscope, allows the operator to easily visualise the preparation margins.

Under X24 power the irregular margins produced under lower power [X10] can be easily identified. Such margins are undesirable, and contribute to poor fit and early failure of the final restoration.

Finalised crown margins X24

The crown margins are refined with microfine diamonds under X24 magnification using a Zekrya gingival protector.

The entire preparation from start to finish, including finalisation of margins, is carried out with a speed increasing handpiece [Red Ring].

Speed increasing hand pieces have improved precision of cutting over a conventional air turbine.

Inspection Of The Impression

The impression is assessed with the microscope in order to determine the quality of the detail captured. An addition cured silicone is used.
The dies are copper plated to improve the marginal fit of the definitive restorations.

The technician will fabricate the crowns with enhanced magnification and illumination using a laboratory microscope.

Evaluation of Crown Margins X24

The crown margins can be easily assessed with the microscope. The increased precision achieved during preparation, and the accuracies of the impression and laboratory stages are reflected in the quality and marginal integrity of the final restorations.

It is not possible to assess, let alone achieve, this level of accuracy without the use of an operating microscope.

Final Restorations

Sympathetic treatment of the soft tissues using the Zekrya gingival retractor has avoided trauma to the gingivae and associated recession.

The use of high levels of magnification has improved the marginal adaptation of the final restorations and therefore decreased the irritation to the gingival tissues.

Both these factors contribute towards improving the prognosis of the restorations.

[Technician: Ian Stapleton]