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28 cosmetic section DENTAL TECHNOLOGY, JULY-SEPTEMBER 2023

A PRECISION WORKFLOW WITHOUT

COMPROMISE FOR CERAMIC REPRODUCTION

LUIS MIGUEL VERA
Color vision is a subjective sensory perception that depends on ambient lighting and the
surrounding colors. That's why Luis Miguel Vera, a dental technician from Seville, Spain, has
developed a strategy to maximize objectivity in tooth shade determination.

He always measures both the shade of the hard tooth substance
directly surrounding the restoration, as well as the shade of the pre-
pared tooth, so that the shade effect of all-ceramic restorations can
be as predictable as possible. The VITA SYSTEM 3D-MASTER shade
standard that seamlessly replicates the tooth shade space is an inte-
gral part of his approach, as are the dental materials that precisely
reproduce the tooth shade he has identified. If 2M1 is measured, it's
obvious that 2M1 should also be used for the substructure material
and veneering ceramic. In the case study below, Vera shows how he
uses his strategy and the true-to-shade VITA AMBRIA and VITA
LUMEX AC materials (all from VITA Zahnfabrik, Bad Säckingen,
FIG 1: Initial situation with a VMK crown on tooth 11 and the fractured incisor (tooth 21).
Germany) to create highly esthetic custom restorations for his
patients.
A COMPLEX CASE
A 42-year-old patient presented at the dental practice because he
was unhappy with the appearance of his esthetic zone. During clin-
ical examination, a deficient VMK crown with deficient margins was
observed on tooth 11. The morphology of the crown did not blend
in with the overall appearance and the ceramic veneering seemed
unnatural. There was an incisal fracture on tooth 21, with the frac-
ture zone covered only by filling composite. Following in-depth con-
sultation, it was agreed that tooth 11 should be restored with an all-
ceramic crown and tooth 21 with a minimally invasive veneer. The
substructures were each to be pressed from the zirconia-reinforced FIG 2: Clinical situation following full crown preparation of tooth 11 and veneer preparation
lithium disilicate VITA AMBRIA to achieve a true-to-shade, precise of tooth 21.
and lifelike foundation for individualization, using the universal
veneering ceramic VITA LUMEX AC in a matching shade. CLINICAL STEPS AND TOOTH SHADE DETERMINATION
Following local anesthetic, both central incisors were prepared or
re-prepared accordingly. This was then followed by in-depth tooth
shade determination, using both the digital VITA Easyshade V spec-
trophotometer, and an analog approach with VITA Linearguide 3D-
MASTER. In doing so, the shades of the prepared tooth were also
determined consistently, and the clinical situation documented pho-
tographically with the selected shade tabs, both with and without a
polarization filter. Due to discoloration of the prepared tooth and
crown (tooth 11), VITA AMBRIA T 1M1 was selected to compensate
for this with more brightness. On the preparation surface of tooth
21 that was not discolored, VITA AMBRIA T 2M2 was used in line

FIG 4: A master model was fabricated in the laboratory to create the restoration substruc-
FIG 3: Documentation of the shade tabs without light reflections (with a polarization filter).
tures in wax.