New dental materials to restore worn teeth – Function and esthetics
When a patient has worn dentition, the treatment is a rehabilitation with the aim of recreating and restoring the lost tooth structure with a tooth-like material. In the last decade, excellent innovative materials of different kinds, such as ceramic reinforced composites and resin infiltrated ceramics, have become available for our restorations to improve everyday.
In this article a case of worn dentition is presented with its workflow and materials explained.
We’ll go through this case of a patient with worn dentition examining the workflow and the materials used for the procedure.
This young man complained about hypersensitivity upon chewing, especially in the posterior area; under examination he showed tooth erosion with alteration of smile line and tooth axis, and shortened teeth.
Intra oral view: palatal enamel has disappeared in some areas, because of the heavy consumption of soft drinks and parafunctional habits.
Occlusal anatomy has been modified by erosion and abrasion process and the enamel has completely disappeared from the occlusal surfaces, except for the outer, peripheral part.
Both upper and lower arch were involved in the wear process:
– the upper arch shows a shortened anterior group and a flat, crooked smile line, so only the 8 anterior teeth will be included in the treatment planning
– the lower arch eroded molars were the most sensitive area, while the 6 lower anteriors had a good structure, so only posterior teeth were included in the treatment
The occlusal view of the upper arch shows decay on 16 and 26 which will be treated with inlay restorations, following the original anatomy. Palatal veneers will restore teeth 13 to 23 and buccal veneers 24 to 14.
For the lower arch, occlusal veneers will be made for teeth 35 to 37 and 45 to 47 to restore the lost anatomy, decay on the 4 molars will be treated and the focus will be on improving the transition from the anterior to the posterior area by reducing the discontinuity between canines and premolars.
As always recommended as a test drive prior any kind of wax-up and record, a free hand composite increment is made to simulate and validate directly in the actual masticatory model, aka the patient’s mouth, the new incisal edge. This is meant to give the technician a frame for the wax-up with a preliminary alginate impression.
At the same time, the palatal surface of the upper central incisors is covered with composite to lift the VDO and simulate the original situation, before all the enamel was lost. The patient is guided in centric relation to record the new vertical dimension. In other words, a JIG through a comprehensive modeling technique.
Once the new bite is checked in terms of available space – anterior and posterior – the new bite is recorded with a very useful chemical cure composite (Luxabite, DMG) created for an easy and accurate bite registration.
After all data is sent to the technician, a wax up following clinical recommendations is built and then transferred back into the mouth through a full mock up with a bis-acryl injectable resin (Luxatemp Star A1, DMG) for both arches. Esthetics and occlusion are thusly checked.
Thanks to the esthetic preview, the smile transformation changes tooth axis and proportion as required during the smile analysis.
For minimal invasiveness the guided preparation technique by G. Gurel was carried out through the mock-up for both buccal and occlusal veneers (Full mock-up technique).
Provisionals were made using the same silicone index and material of the mock-up. As you can see, a little crown lengthening was performed by gingivectomy on teeth 11, 12 and 13 to align zeniths.
Lab work with occlusal veneers on posterior teeth.
Anterior view of the upper arch lab work, where sandwich restorations (Vailati F.), palatal and buccal veneers, were fabricated.
Functional veneers (palatal and occlusal) were fabricated with a new generation of composite blocks.
Buccal veneers were made of lithium disilicate (emax LT).
Composite CAD CAM block: this material features physical properties that lay right between those of ceramic and hybrids.
The main reasons for choosing a composite block (Luxacam composite, DMG) were two:
– millability of the material to reach 0,5 mm
– wear behavior of the material very enamel-like, which is essential in that case because of the nature of the antagonist and the masticatory parafunction of the patient.
View of the sandwich restorations in the anterior during try in (Vitique veneer, DMG).
After simultaneous bonding procedure of both veneers.
Individual dam isolation during the adhesive procedures for the occlusal veneers.
View of the palatal veneer made with Luxacam composite DMG.
You can note the mimicry of the material.
Occlusal veneers from 35 to 37. MarginW are invisible.
Occlusal veneers are seated on the original occlusal anatomy.
Occlusal view of the restored lower arch.
Occlusal view of the restored upper arch.
Final view of the integrated veneers. A special thanks to Hilal Kuday CDT (Bodrum) for this masterpiece and his incredible work.
New smile with correction of the axis and tooth proportion.
Many smart and innovative products have appeared on the market the last ten years, especially with regards to CAD CAM workflow. Of course it is of utmost importance to get a deep understanding of the features of these materials, in terms of type of material, physical properties, thickness limits. Then the dentist and the technician must build a harmonious workflow and thoroughly discuss clinical and technical parameters. Last but not least, mechanical conditions, i.e. the nature of the antagonist, and chemical conditions, i.e. acidic environment, must be analyzed to better predict the long term prognosis of the rehabilitation.