PREVENTION OF IATROGENIC ISSUES IN ANTERIOR RESTORATIONS
Figure 3: Maxillary occlusal view of the patient’s original restoration
Figure 4: The diagnostic wax-up
Figure 5: The provisional crowns during try-in
After the equilibration was completed and the lingual porcelain
reduced on the anteriors, the patient felt “back to normal.” Diagnostic
models of the refined occlusion were taken, along with measurements
using the Kois Dento-Facial Analyzer facebow (Panadent), and sent to
the lab for a diagnostic wax-up. The lab was instructed to keep the
lingual surface the same to prevent the speech issues from returning.
The lab technician was also given direction on incisal edge position
and other esthetic corrections. 2 The diagnostic wax-up was returned
with a putty matrix and a vacuform stent ( figure 4). The putty was used
to try in the proposed treatment directly in the patient’s mouth with
bis-GMA provisional resin. She gave approval on the proposed treatment and liked the esthetic improvements. The final color was chosen,
and the patient was appointed to correct gingival levels on the central
incisors with a hard-tissue laser crown-lengthening technique.
The Waterlase MDX (Biolase) was used for the surgical osseous
crown lengthening, along with necessary soft-tissue refinements. 3 The
patient was given post-op instructions and returned one week later so
we could monitor healing. The gingival tissue was allowed to completely
heal for 90 days. The patient returned around the 70-day mark and was
examined and scheduled for the longer appointment of crown preparations. The patient decided that she would like to have a nicer smile and
wished to have a much lighter color and to treat additional teeth. The
upper 10 anterior teeth were going to be treated initially.
The patient returned for the preparation visit. The existing crowns
were removed and the teeth, including the additional bicuspid teeth,
reprepared. A final impression was taken with a PVS impression material, Imprint 4 VPS (3M Oral Care) heavy body and light body, and
Impressiv (Cosmedent). The provisional crowns were fabricated from
the putty matrix with bis-GMA resin (Mirror Image, Cosmedent) and
seated with a temporary cement ( figure 5). Additional models were
taken of the temporary crowns and a facebow was taken of the provisionals ( figure 6). A bite was taken against the opposing arch with both
the prepared teeth and the temporaries. This was sent to the lab with
instructions to fabricate the crowns with layered lithium disilicate. IPS
e.max Press (Ivoclar Vivadent) was used.
The patient returned three weeks later for the final insertion. The
temporaries were removed and the preps cleaned with air abrasion,
using 27-micron aluminum oxide. 4 Retraction cord impregnated with
aluminum chloride was placed.
The options for proper cementation must be carefully considered
ahead of time. The cementation can be cohesive or adhesive. The decision was made to use an adhesive cementation process. The cement
that was used was Bisco’s eCement. Since the crowns were fabricated,
this dual-cure cement ensured a complete cure. The formulation is
available in a single-stage cure for veneers and a dual-stage for crowns,
as well as several shades.
The enamel was selectively acid etched with Select HV Etch (Bisco).
This is a 35% high-viscosity phosphoric acid etchant available with