aesthetic anteriors and reallife porcelain

Anterior Aesthetics with Cerec And Vita “Reallife” Dr Paul Moore, BDS. 1981 General Dental Practitioner, Galway, Ireland. ISCD Trainer for Cerec Chairside Dentistry. drpmoore@mac.com www.gateclinic.com

Abstract Cad Cam chairside dentistry has increased In popularity and diversity of application. This is due in part to the improvements in the software and the easing of the learning curve for the clinician, but also the demand for aesthetic restorations and the convenience of one visit dentistry. The range of materials has likewise expanded to allow a greater choice in range of “shades”, or more correctly described as the combination of hue, chroma and value.

This article described the use of Vita’s “Real Life” porcelain blocks which allow the clinician to diferentiate the distribution of enamel and dentine within the final crown to simulate the varying transluscencies of the natural dentition.

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Initial Presentation The patient was a 30 year old female and presented with concerns about her aesthetics. The midline diastema concern her but she was very critial about the irregularity of the gums and length of her teeth as well as the mismatch in colour and transluscencies between the six front teeth.

Initial Presentation

Dr Paul Moore. Aesthetic Anteriors with Cerec and Vita Reallife

Radiographic Assessment Tooth 23 had previously been root treated following canine re-implatation many years ago. The periapical tissues appeared withing normal limits. The roots of 23 and12 were both foreshortened but with no mobility. Buccal feldspathic veneers were present on the 13 and 23, feldspathic full crowns present on the 12 22 with zirconium cores and 23 was root treated.

Periapicals show foreshortening of roots 12 and 23 particulalry, with root canal therapy on 23.

PDL and periodontl support however are within normal limits and have been stable for the 5 years I have know the patient.

History The patient had been the recipient of dental attention for a long time. With orthodontics 15 years ago with canine transplants. Later porecalin veneers on the canines and full crown coverage on the lateral incisors. The 23 had been root treated succesfully.

While well aware of the options available and with a healthy respect for as conservative approach as possible, the patient was unhappy with the appearance of her smile and the lack of canine contact influenced the function as well as the aesthetics.

Aims of Treatment.

To imrove the ginigval contour.

To establish a harmonious relationship between the crown length and width.

To close the midline diastema.

To create a natural appearance in keeping with the personal profile of the patient.

To increase the length of the canines to establish canine guidance.

Stage 1.

Crown Lengthening.

Having established our desired contour of the gingival margins using study models and suck down stent, first we marked of the planned ammendments. With bone re-contouring and gingival repositioning the desired gingival architecture was established.

Eight weeks were left for adequate healing and tissue maturation.

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Dr Paul Moore. Aesthetic Anteriors with Cerec and Vita Reallife

Stage 2.

Colour Analysis

The range of materials available with cad cam chairside restorations has increased significantly with feldspathic porcelains from several manufacturers and newer materials all with diferent physical and optical qualities. The ability to bond feldspathic porcelain has been tried and tested and success rates of 95 % over 15 years. The chosen material for the new crowns was to be monoblock felspathic porcelain which which could be bonded with a silanised etch and bond protocol to give maximum bond strength.

The Vita “Real Life� block also offers a variable distribution of enamel ( with a higher transluscency ) and dentine ( with increased value ) to simulate the chosen degree to suit the patient. This can be chosen at the time of preparation and design with the patient present for immediate confirmation.

Shade analysis picture to be inserted

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Dr Paul Moore. Aesthetic Anteriors with Cerec and Vita Reallife

Material Choice The range of materials available with Cad Cam chairside restorations has increased significantly with feldspathic porcelains from several manufacturers and newer materials all with diferent physical and optical qualities.

The ability to bond feldspathic porcelain has been tried and tested and success rates of 95 % over 15 years. The chosen material for the new crowns was to be monoblock felspathic porcelain which could be bonded with a silanised etch and bond protocol to give maximum bond strength.

The Vita “Real Life” block also offers a variable distribution of enamel ( with a higher transluscency ) and dentine ( with increased value ) to simulate the chosen degree to suit the patient. This can be chosen at the time of preparation and design with the patient present for immediate confirmation.

Minimal veneer preperation of the incisors for veneers, but with incisal reduction for length adjustment.

Margins kept supra-gingival allow for easier cementation and maintenance. Also allows full • enamel peripheral etch and bond.

Finish margins and labial surface with fine diamond and air abrasion creates a finer finish.

• The finer fit is easier to manufacture a precision fit to, and easier to seat.

• Supragingival margins are easier to maintain.

• Enamel, composite,porcelain interface provides an excellent chameleon effect.

•

Stage 3

Bite Registration

The functional bite registration of the envelope of movement of the canines to the opposing teeth can be recorded.

The functional bite registration of the envelope of movement of the canines to the opposing teeth can be recorded.

Using a suitable registration material (“Triad” light cure denture reline material) , the movement of the opposing teeth on the uncured material is recorded and the surface of this is scanned in situ.

The palatal surface of the proposed crown can then be designed to match this range of movement.

Dr Paul Moore. Aesthetic Anteriors with Cerec and Vita Reallife

Stage 4

Sequencing

When this proceedure is to be completed chairside the main advantage is the patient is with you the whole proceedure.

In this case tooth 12 was prepared first and imaged designed and milled to establish and verify the centre line and incisal edge were as required.

• This “ central “ requirement becomes the cornerstone for the remainder of the proceedure which in this case was completed in one visit. ( 8.30am - 2.00 pm ) Once the design had been completed for the first tooth prepared, the milling was commenced.

•

Teeth 22, 23 were then prepared, imaged, designed milled from one set of images.

•

Teeth 12 13 likewise once the milled 11 was placed with try in paste. This gaurantees the centre line and incisal edge required.

•

Finally the 21 is prepared with the 22 23 in place distally and the 11 in place mesially.

This creates a relaxed, achievable, controlled preparation design and milling protocol, and facilitates a one visit reconstruction from start to finish for the patient and dentist.

Canine proposal, showing canine contact point

Full facial within enamel proposal

Dr Paul Moore. Aesthetic Anteriors with Cerec and Vita Reallife

The block has been rotated and moved to visualise the proposed distribution of enamel / dentine

Cross sectional view to see position of chamfer line and angle betwen enamel and dentine selected.

Stage 4

Try in and Cementation.

Having milled the two veneers for the central Incisors, and the full crowns for the canines and lateral incisors, these can then be polished and using a try in paste the final design can be shown to the patient for approval.

At this stage any minor surface characterisations can be added and glaze applied in a 12 minute firing cycle. Further refinements if required can be made by using final composites luting cements with varied shades to lighten or darken the finish result.

Porcelain preparation.

1.Hydroflouric acid for 2 minutes, wash dry.

Tooth preparation.

2.Phosphoric acid 10 second. Rinse thoroughly.

1. Lightly clean with sodium bicarbonate “airpolish�

3.Ultrasonic bath in distilled water. 2 minutes.

2. Light rinse with sodium hyperchlorite 5%.

4.Dry thouroughly with warm air.

5.Silanising agent applied. ( as per manufacturer’s instructions)3. Phosphoric acid (35%) etch enamel and dentine.

4. Bonding agent applied , gently air thinned, light 6.Bonding agent applied , gently air thinned, light cured. cured.

Cement applied to restoration and cemented one at a time, starting with the two central incisors. Flossing mesail and distal to remove supra and subgingival composite before light curing.

We prefer to use radio-opaque composite which facilitates long term radiographic monitoring with ease.

Stage 5

Finishing

We use interdental strips of decending abrasivity to finish interproximally, and fine scalpel to remove excess cement facially and palatally. Any minor adjustments are made under magnification with fine diamond burs. This is easiest when the preparation are supragingival. In this case the preparation margins for the canines and lateral incisors had been placed subgingivally by the previous restorative attempts.

Final review a few days later to assess the patients lip line, speech occlussion and periodontal status should be obligatory.

Dr Paul Moore. Aesthetic Anteriors with Cerec and Vita Reallife

Discussion and Conclusion.

The combination of materials and techinques allows for a uniform finish mechanically and aesthetically for the upper anteriors, giving a harmonious blend of translusceny and surface characterisation.

The material choice was dictated by the desire to have control over the optimal distribution of translusency and opacity from incisal edge to cervical margin. Using the chairside Cad Cam gives the advantage of same visit try in and patient feedback.

The strength of the feldspathic porcelain when bonded to the underlying enamel with etch bond and silanisation with a composite luting agent will provide a prognosis of 95% success over 15 years. No parafunctional activity was relevant in this case and Vita Realife cereamic blocks provided an excellent solution.

Being ciritical of my proceedural decisions postoperatively I would have minor concerns about the varient design of veneers on the central incisors and full crown coverage on the lateral incisors and canines. The diference in substructure between between the veneer preparations on the central incisors compared with the full crowns on the laterals and canines was dificult to compensate with the materials and transluscencies, but the ability to vary the proportion of “enamel to dentine” with the “Reallife” blocks facilitated those compensations required to achieve the finished result.