Crowns – Smile Rejuvenation

Patient initially presented for improving the aesthetic appearance of upper teeth (especially the upper front four crowns placed more than 25 years ago with discoloured gum margin); the emergence profile of upper four crowns 12-22, and the black margins around the upper four crowns. The patient prefers to wear red lipstick, but cannot wear it as it emphasizes the upper four front crowns that are now defective and in need for replacement. General tooth discolouration and teeth wear (shortening of the teeth over the years) was also a concern.

COMPLEX AESTHETICS: METAL CERAMICCROWNS:
REPLACEMENT WITH ZIRCONIA BASED CERAMIC CROWNS



Smile Rejuvenation



Initial Presentation



The patient prefers to wear red lipstick, but cannot wear it as it emphasizes the upper four front crowns that are now defective and in need for replacement. General tooth discolouration and teeth wear (shortening of the teeth over the years) was also a concern.

Note the stained composite repair of fractured porcelain crowns. This is an ideal clinical situation, where to maintain the longevity of the dentition and improve the aesthetics of the upper arch, replacement is needed of existing crowns and crowning teeth with reduced compromised integrity (heavily filled, cracked teeth, where considerable bite forces are exerted from bruxing/tooth grinding).



Patient also wishes to widen the upper arch to fill in the dark lateral corridors, especially on the right hand side as well as improving the triangular shape of the original crowns. From diagnostic measures, it is evident that the slightly thinner upper lip will be improved in thickness, a desire of most women patients in our practice.

The palatal tooth erosions are caused by lemon acid diet erosive lesions on upper teeth. Previous gum surgery has created longer clinical crowns. Upper front four crowns placed 18-20 years ago following completion of orthodontic treatment. We must appreciate the long life of these metal ceramic crowns that are still regarded as superior quality today as we have over 50 years of experience with metal ceramic crowns. However many patients today desire non-metallic crowns such as zirconia or glass based ceramic restorations.

Note heavily restored upper right premolars. Note the decay formation between the amalgam filling and the buccal cusp (outside part of the tooth). Upper left first molar has also a fractured palatal cusp, large amalgam restoration. The canines and the premolars have lost considerable enamel from intrinsic acid induced erosions. The prognosis of the dentition, if left untreated would be affected. No treatment is not an option: since consequences of no treatment, will lead to further deterioration of the upper dentition.

Following examination, x-rays, photos and study models and composite mock up etc. confirms the following:

1. Moderate smile line with upper teeth midline is in symmetry with upper lip. During full smile we have symmetrical exposure of gums. This combined with discoloured, chipped restorations, teeth affected aesthetic display of the smile. However the narrow upper arch gives the effect of ‘dark lateral corridors”
2. Good lip thickness, outline and contour. Smile dynamics: symmetrical.
3. Bruxer, multiple fractured cusps, loss of canine guidance
4. Posterior teeth canines and premolars have compromised structural integrity and would benefit from full crown coverage



Patient was concerned re: unnatural emerging crown margins and discoloured repair of the fractured porcelain on upper front four crowns.

Patient presented with optimal dentofacial symmetry.

1. Ideal lip form and outline
2. Eye levels
3. Cheek bone
4. Saggital and oblique profile views. You can see the entire smile outline and length.





Patient maintains excellent oral hygiene. The slight redness on tooth 22 is due to defective composite

repair. Note the dark root discolouration on four front teeth. This is due to discoloured root from past root canal therapy. This is difficult to treat, since the gums are thin (we refer to this as thin biotype, thin bone and gums) and dark discolouration projects through the bone and the gums.



Note heavily restored upper right premolars. Note the decay formation between the amalgam filling and the buccal cusp (outside part of the tooth). Upper left first molar has also a fractured palatal cusp, large amalgam restoration. The canines and the premolars have lost considerable enamel from intrinsic acid induced erosions.


Diagnostics



Direct composite mock up on existing crowns to assess the length of the new desired smile line.

Assessing the symmetry across the midline

Note the left central incisor is slightly long and is modified. Optimal lip support is achieved.

We also have optimal tooth display across the midline with symmetrical lip outline & thickness.

Diagnostics: Our patient is happy with the assessment of the new arch shape, position and level of display. It is interesting to note how patients smile with their eyes.



Composite mock up: all agree with the level and arrangement of tooth display, improving the arch width, hape and teeth exposure.

The composite mock up established a new smile line, optimal arch position and level of tooth display. We tested the speech and smile dynamics. With the new crowns and reconstructions, we will be redirecting the teeth movement to reduce further damage to the posterior (back) teeth. This is most important, because there is a crushing post (back) teeth during excursive movements, since we have lost the anterior guidance from anterior wear. The new direct composite mock up established anterior guidance and smile line.

Diagnostics: correct treatment planning helps our patients to visualise the final result, which builds confidence and reduces any unwanted anxiety. Both Dr Nalbandian and the patient can visualise and plan together the best possible patient outcome.



The aim of the treatment plan is to improve arch width laterally, reduce emphasis on upper front, and improve the arch shape, degree of tooth display and naturally improving the colour of the teeth. The space present at missing site 25 can be treated either by orthodontic treatment to open space and consider an implant placement, or we can simply bridge this across since adjacent teeth would require crown coverage. Orthodontic treatment is not an option for the patient who prefers restorative replacement of tooth 25.

Tooth preparation is usually the last resort that Dr Nalbandia will attempt after careful consideration of all conservative measures. In this case all the teeth treated (four upper front teeth with previous crowns requiring replacement) have structurally compromised integrity and considerable tooth surface loss from acid erosion, requiring reinforcement using full crown coverage. No treatment would have resulted in further deterioration of most of the upper dentition. Very careful treatment is required to maintain the remaining tooth integrity to house the new ceramic crowns as requested by the patient.



Expert knowledge and good pair of hands are required to maintain the delicate curvature of the gums for correct emergence profile of newly designed crowns!



Due to past extensive dental treatment and tooth breakdown, it is difficult to assess the structural integrity of the tooth core, which will be decided at the time when the existing crowns and bridges are removed. It is also difficult to assess if there will be changes in the pulpal (tooth vitality) status before, during and after completion of the proposed dental treatment. All types of porcelain crowns and veneers require some form of tooth preparation. It is acknowledged in the international dental literature that there is a 10-20% chance of possible postoperative sensitivity which may require further treatment (such as root canal therapy). Unfortunately the dark root discolouration (from past root canal therapy) projecting through the thin gums above the gum margins will remain. The new porcelain crowns will mask the dark crown margins present.

As always, following cosmetic dental procedures a habituation period of few days is anticipated. Any sensitivity, if present is usually transient.

Following considerable discussion regarding various options of treatment including no treatment, we decided to proceed with restorative treatment using porcelain crowns on teeth (15, 14,13,12,11,21,23,24 & 25) and missing tooth 26 with bridgework. Considerable erosion is present on teeth 15, 14, 13, 23, 24 & 25 necessitating crown placements.



Laboratory stage: The zirconia based crowns and the bridgework prior to cementation Note the “foot prints” of the lower teeth sliding and impacting on metal surfaces of the old metal ceramic crowns. These forces will also be directed to the new crowns as well. On the lower image, it is quite apparent how the gum discolouration (arrow: shadowing from dark metal crowns that do not allow any form of light transmission). In many ways this discolouration is also related to possible chronic allergies to the metallic components of the metal ceramic crowns. The advantage of ceramic systems such as zirconia supported crowns is that the allergy component is eliminated due to high inertness and stability of zirconia.





Initial issue: upper eleven units of crown and bridgework on upper arch.

Note the improvement in lip outline and upper lip thickness and teeth exposure at rest, as requested by the patient.

Initial assessment of dentofacial aesthetics: at the try in stage of maxillary (upper) arch reconstruction.

Future bruxing/grinding habits will play an important role in the future longevity of the new crowns/bridges, whether it is tooth or an implant supported as well as the entire dentition.

A night guard is usually provided to control any bruxing.

Nightguard provided by Dr Nalbandian after every complex reconstructive treatment is to protect the new restorations and integrity of the dentition.

Generally if you dislike your smile you simply do not smile!

Patient disliked the short worn crowns and dark metal margins of the old but functional metal ceramic crowns.



Rehabilitation of maxilla (upper arch) using full zirconia crowns and tooth supported bridgework.

New Technology does provide better aesthetics that today’s society demands. Naturally you can see the difference in the dentofacial aesthetics of this elegant lady. However it is essential to wear the night guard provided to maintain the longevity of the new crowns and of course the new beautiful smile!

Note the retruded position of the narrow upper arch. This only emphasises the old, worn metal ceramic crowns on four upper front teeth, which this patient disliked considerably.

The importance of diagnostics and planning cannot be overestimated to achieve this final result as shown after treatment

Note improved arch position and shape. We widened the upper arch and improved toothteeth display in relation to lower lip form that is in harmony with patient’s dentofacial appearance.



One Smile says it all!

Oblique View: Note new improvement in lip support, tooth colour, form and shape, teeth display, smile line upper dental arch position and shape. Rejuvenated: dentofacial aesthetics.

All above procedures were performed by Dr Sarkis Nalbandian.

Education and Experience are everything.

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