Getting the perfect look when restoring anterior teeth with different kinds of situations is a huge challenge. Laminate veneers have been used for the last forty years with the aim of achieving esthetic results in the anterior area, by recreating color and morphology in a minimal invasive way. One of the most common issues is having an old crown right in the middle of the smile composition. The challenge for the dentist and technician is to get the exact same tooth color between laminate veneer and crown. For this reason, the quality of the substrate and its color under the crown is the key to improve the final esthetic outcome.
The purpose of this article is to highlight the clinical strategy and methodology to create the best mimicry between different restorations. The use of fiber post with dual cure composite in one step will be presented.
38 years old female patient had old composite fillings and unaesthetic crowns on 11 and 24.
She was looking for a smile makeover. No pathologies or diseases were noted. Occlusion is stable. The chosen treatment plan was:
1- Replacing old composite fillings with single mass (dentin-body) restorations to get better optical continuity with the substrate after veneer preparation.
2- Removing metal crown and screw post followed by fiber post core build up restoration to improve the homogeneity of the abutments thanks to the adhesive properties, and try to improve color matching with the use of glass ceramic for the final restoration as for the adjacent laminate veneers.
3- Laminate veneering and crown from 13 to 24 made with the same material (Ivoclar Vivadent, IPS e.max LT) in order to have a homogeneous color value between the different restorations.
As presented in the treatment planning, step 1 is carried out by converting biological and esthetic obstacles in integrated fillings.
Class 3 single mass composite restorations were performed with the use of dentin shade composite (Ivoclar Vuvadent, Empress direct dentin A1) for 12, 21, and 22. These teeth are supposed to be slightly prepared for veneers, that’s why the semi-opacity of the proximal fillings is important to avoid esthetic disturbance behind the 0.5 mm buccal ceramic veneers which will be made.
Then the old crown is removed. As happens with many old cemented restorations, bacterial infiltration occurred in the cervical area with the black line and the corrosion of the screw post through the composite.
Composite is carefully removed and the screw post is unscrewed with an ultrasonic system (Mectron) in order to preserve tooth structure in the cervical area.
A fiber post reconstruction using the all-in-one concept is performed, which means simultaneously filling the root and crown parts with the same material to get maximum homogeneity and biomechanical integration.
DMG LuxaPost, DMG LuxaCore Z-Dual, and DMG LuxaBond-Total etch and a core form were used for this case.
As previously mentioned, thanks to the optical characteristics of the material and the use of an all-in-one concept, the homogeneity of the abutment was consistently improved.
LuxaCore Z-dual composite is a versatile material for everyday practice, not only for fiber post cementation and build up, but also for deep marginal fillings where polymerisation stress is an important concern (3-4 mm heigh proximal cavity).
This product is available in two formats:
- cartridge with the use of dispenser
- smart syringe
In both cases T-mixer colibri is available to make injection accurate and versatile.
Crown preparation is performed with a 1.5 mm thickness reduction in the cervical area to allow more freedom for the ceramist to cover the severe cervical dyschromia.
Ivoclar Vivadent e.max LT A1 ingot will be used for veneer and crown as well; the only differences will be the thickness of the restoration between crown and veneers. To avoid ending up with a greyish effect on the crown due to the important thickness and translucency of the ingot, the ceramist will apply deep dentin powder with a certain opacity to align the framework with the adjacent color. Then, the layering used for veneer and crown will be the same to control the homogeneity of color value between the different restorations.
Communication with the lab through pictures is mandatory, especially for difficult cases like this one in which substrates are not aligned color wisely.
First, record the shade of the substrate after preparation with a natural die shade guide (always select 2 options always). Then, record the shade of the lower teeth with a VITA shade guide to copy the final expected color.
Because of personal reasons, the patient couldn’t come for veneer preparation for 3 months, so we decided to use DMG LuxaCrown for the provisional crown.
This syringeable, self cure resin is very useful for long term provisionals or semi permanent restorations. The semi-opacity of this material allows the masking of the severe cervical dyschromia, which is almost impossible to get with the classical translucent syringeable provisional materials on the market.
Different bonding procedures were carried out based on the ideal protocol for the different restorations. Teeth were individually isolated. You can note the good aesthetic integration of both types of restorations (crown and veneer) even if the substrate and the thickness were different.
I wish you take home the following message: the key to mixed restoration cases is to start with converting all the initial challenging situations in well integrated fillings to match with the final outcome the patient and the dentist are looking for.
Again, as in this particular case, a core build up following a standardized clinical sequence with the proper material is an important key of the success for mixed restoration cases, when redesigning a smile. The biggest challenge and issue is the color value homogeneity. The dentist must have a clear vision of the initial situation and the final result in order to fix first all the dark areas and then be able to match with the final aesthetic result.
– Lamichhane A, Xu C, Zhang FQ. Dental fiber-post resin base material: a review. J Adv Prosthodont. 2014 Feb; 6(1): 60–65.
– Hattory M, Takemoto S, Yoshinari M, Kawada E, Oda Y. Durability of fiber-post and resin core build-up systems. Dent Mater J. 2010 Mar;29(2):224-8.
– Ozcan M, Valandro LF. Fracture strength of endodontically-treated teeth restored with post and cores and composite cores only. Oper Dent. 2009 Jul-Aug;34(4):429-36.