veneer preparation bur grooves style italiano styleitaliano

Mock up: A versatile tool for everyday practice

The concept of “Mock-up” was first proposed in the early 2000s with the main purpose of making it possible for the patient to see something very similar to the final outcome, before starting treatment.
This article is an update and a presentation about 3 different topics, and about how the mock-up is involved in different treatment plans. In esthetic and functional treatments, the final result should be visualized as early as possible when planning procedures. This approach ensures that all parties involved with the case have the same endpoint in mind and allows changes to be made prior to the final restorations being cemented. I’m going to illustrate how it’s managed in three different workflows:
1- no-prep cosmetic approaches
2- prep-less cosmetic approaches
3- prep-less in the rehabilitation of worn dentitions

peg lateral teeth

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.

peg upper lateral styleitaliano

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.

mock-up of upper incisors dmg

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.

preparation of lateral incisors through the mock up

Fig.4

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

close-up of peg lateral incisor

Fig.5

Differences between no prep and prep less is barely noticeable.

veneer preparation on lateral incisor

Fig.6

But much more practical for the dental team.

mock up used as a resin provisional and splint

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.

no prep restoration

Fig.7a

Try in of the no prep restoration

Bonding protocol of ceramic chips

Fig.7b

Bonding protocol of ceramic chips made with monolithic press ceramic (emax press MT A1)

:Appearance after bonding

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)

diamond bur on central incisors styleitaliano

Fig.8

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

arkansas for incisor polishing

Fig.9

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

grain silicone disc tooth

Fig.10

Step 3: silicone medium.

silicone polishing tip

Fig.11

Step 4: silicone fine.

silicone polishing bur

Fig.12

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

multiple veneer preparations

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

old restorations on incisors

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.

mock-up resin before finishing

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).

multiple veneer preparation mock up guide

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

veneer preparation bur grooves

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.

multiple veneer preparations with retraction cord

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

provisional veneers with DMG resin

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.

provisional veneers before cementation teeth

Fig.20

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

single veneer bonded tooth

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.

posterior mock up preparation

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).

worn dentition styleitaliano

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

occlusal tooth wear style italiano koubi

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.

resin functional mock-up koubi

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.

occlusal mock up check

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.

posterior mock up preparation 3 step

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

occlusal veneer preparation

Fig.28

Contemporary design for occlusal veneers.

single rubber dam isolation tooth

Fig.29

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

palatal veneer cementation

Fig.30

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

sandwich veneer technique

Fig.31

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

upper ceramic veneers

Fig.32

Thanks to ceramist Gerald Ubassy (Rochefort du Gard).

palatal functional veneers

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

1. Mizrahi B. Porcelain Veneers: Techniques and precautions. Int Dent SA. 2007;9(6):6-16.
2. Koubi S, Gurel G, Margossian P, Massihi R, Tassery H. A Simplified Approach for Restoration of Worn Dentition Using the Full Mock-up Concept: Clinical Case Reports. Int J Periodontics Restorative Dent. 2018 Mar/Apr;38(2): 189-197.
3. Gurel G. Predictable, precise, and repeatable tooth preparation for porcelain laminate veneers. PractProcedAesthet Dent. 2003; 15(1): 17-24
4. Magne P, Magne M. Use of ad- ditive wax-up and direct intraoral mock-up for enamel preservation with porcelain laminate veneers. Eur J Esthet Dent. 2008 ; 1(1): 10-19.
5. Vailati F, Belser U. Classification and treatment of anterior maxillary dentition affected by dental erosion: the ACE classification. Int J Periodontics Restorative Dent. 2010 Dec;30(6):559-71.