Fig.1
1- No Prep Cosmetic Approach
The no prep concept is becoming very popular both due to patient demand and advertising influence. And, as a matter of fact, from the point of view of both dentists and ceramists, there is a very slightly noticeable difference between a no-prep and a prep-less approach.
On the other hand, the predictability and repeatability of the execution of this clinical protocol is not comparable.
Only a few cases are really compatible with a purely additive approach; most cases need to be planned with at least some reduction on the initial volume, and then applying a wax up. And this is the only way to create a nice emergence profile and a natural appearance.

Fig.2
Post-orthodontic treatment of microdontia and diastemata have a strong indication for a very good no prep restoration. In this case, a young patient was wishing for an improvement in the design of her smile after treatment. The first important step is to analyse the smile composition in order to identify where we want to ideally place the white corridor. In other words, improving the shape of her peg lateral, is not enough, and some volume has to be added as well on the distal part of the central incisor and mesial part of the canine to get the ideal composition. So, in this case, 4 no prep restorations (chips on 13, 11, 21, 23) and 2 laminate veneers (12 and 22) were proposed. The purpose of the mock-up here, is to to identify and validate the good volume distribution between the 6 anterior teeth.

Fig.3
Once the mock-up (DMG Luxatemp Star Shade A1) is stamped into the patient’s mouth, we have full visualisation of the future esthetic outcome. Note that, for this first try, 12 and 22 are too long and need to be shortened a bit.

Fig.4
So the mock up is used as a guide just for veneer preparation on 12 and 22, with buccal and incisal reduction.

Fig.5
Differences between no prep and prep less is barely noticeable.

Fig.6
But much more practical for the dental team.

Fig.7
After one month, the provisionals are still very stable and esthetically pleasant, and play as a splint for the 6 anteriors. The night retainer can’t be used during the treatment, this is why joint, monolithic bis-acryl resin provisionals are mandatory.

Fig.7a
Try in of the no prep restoration

Fig.7b
Bonding protocol of ceramic chips made with monolithic press ceramic (emax press MT A1)

Fig.7c
Appearance after bonding of 11,12,13 following the sequence 11,13 and 12 in order to start with the weakest pieces and finish with veneer (Ceramist Hilal Kuday CDT)

Fig.8
Polishing sequences for no prep restorations. Step 1: diamond bur
(Komet kit, Symbiose JF Lasserre)

Fig.9
Step 2: Arkansas (Komet kit, Symbiose JF Lasserre)

Fig.10
Step 3: silicone medium.

Fig.11
Step 4: silicone fine.

Fig.12
Step 5: silicone shiny, no water spray, low speed.

Fig.13
2- Prep Less Cosmetic Approach
When a no prep approach is not advantageous, even though we’re still facing a cosmetic case, the mock-up is not only intended to visualize the final outcome, but also to guide the preparation

Fig.14
This patient was already treated with veneers about 6 years ago, but he’s still looking for a brighter smile. So we decided to fabricate 10 veneers (15 to 25) to enhance the upper teeth.

Fig.15
To meet the patient’s demand, the additive mock-up was fabricated using a very bright bis-aryl resin (DMG Luxatemp Star Shade Bleach Light).

Fig.16
Once the mock up validated by the patient in terms of design and color, it stays in the mouth, in order to be used as a preparation depth guide.
The incisal grooves are 2 mm deep, to allow a 1.5 mm reduction for the future incisal edge position

Fig.17
The facial surface of the mock up, which represents the actual final volume, is prepared with a depth cutter bur (Komet 868A 314 021).
Two 0.5 mm deep grooves are create not he buccal thirds avoiding the cervical part, in order to preserve cervical enamel. Not to touch the cervical enamel with this bur, its shaft should be held parallel to the crown axis.

Fig.18
After the thickness and the depth reduction, the dentist should focus on the preparation design and follow some basic rules:
– Respect buccal convexity
– Cervical margin located 0.5 supra gingival
– Proximal preparation margin at half the thickness of the contact area

Fig.19
As well as being useful for visualisation and preparation, the mock-up should also be used as a provisional restoration.
For this purpose, we only use a bonding agent (no etching) and then light cure the same material (DMG Luxatemp Star Shade Bleach Light) on the prepared teeth, with the silicone index as a stamp. In order to get a nice surface texture and an anatomy similar to that of the waxed-up teeth, it is highly recommended to let the material set for 5 minutes before removing the silicone index, in order to achieve a complete curing.

Fig.20
Color and surface texture after one month. The material is mechanically and optically stable.

Fig.21
Cementation of the veneers is carried out by using the individual dam technicque, so each and every single veneer is bonded, one by one.

Fig.22
3- Prep Less in Worn Dentitions, the Full Mock-Up Concept
The first step in this visualization process is the diagnostic wax-up created on the models mounted with the new centric relation. The purpose of raising the occlusal vertical dimension (OVD) is to restore the occlusal morphology on worn dentition being as minimally invasive as possible, and to restore the smile line with a proper thickness of the restorative material. This will allow the clinician and technician to have more freedom improve occlusion and reduce stress on the muscles. This allows to restore anterior guidance and correct the occlusal anatomy. In most cases, recreating the ideal morphology and obtaining optimal esthetic results with minimal preparation would be almost impossible without changing the OVD, which means the required space for anatomic reconstruction will dictate the new OVD recorded on the patient, giving the technician all the information he needs.
Four clinical steps are linked to four appointments, to propose a standardized treatment that is repeatable and predictable; we have named it the Full Mock-Up Concept (2018).

Fig.23
Step 1: Creating an esthetic and functional treatment plan.
Initial situation with eroded dentition on both sides. The patient is looking for a smile enhancement and protection of the tooth structure

Fig.24
On the occlusal view, there is almost no enamel on the functional surfaces, which was easily explained as the patient used to drink a lot of acid soft drinks during his childhood.

Fig.25
Step 2: Testing the new wax-up with the new OVD.
The mock-up is stamped into the patient’s mouth, both for an aesthetic validation, and for functionalization.

Fig.26
Minor corrections are carried out during the occlusion test, until the patient is fully stable and guidances are neat. Thanks to the full mock-up esthetic and function are simultaneously checked.

Fig.27
Simultaneous anterior and posterior tooth preparation for maxillary mock-up (DMG Luxatemp Star Shade A1). Three grooves on the occlusal surface with 0.5 mm depth are performed:
– Interior part of the buccal cusps (1 mm below the top of the cusp)
– Interior part of palatal cusps (1 mm below the top of the cusp)
– Central fossae

Fig.28
Contemporary design for occlusal veneers.

Fig.29
Step 3: Cementation of the upper arch restorations and preparation of the lower arch.

Fig.30
Palatal view after sandwich bonding. Each tooth is completed under single-tooth dam isolation.

Fig.31
Occlusal view to highlight the new volume comparing with the existing one on buccal and palatal aspect.

Fig.32
Thanks to ceramist Gerald Ubassy (Rochefort du Gard).

Fig.33
Here’s how the functional veneers look after 6 months.

Conclusions

As presented in this article the mock-up is the key element of every single esthetic treatment. The advantages are not only about the aesthetic project validation, but also about controlled preparation and function. In short, the mock-up is today to be considered crucial for three main reasons:
1- visualisation of the final outcome (aesthetically and functionally)
2- guide for the buccal or occlusal reduction
3- fast and simple provisionalization

Bibliography

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