Page 11 - GP spring 2023

A 3D Printed Approach to Anterior Provisional Fabrication

Authors: Aadel Soleymani, DDS and Arthur R. Volker, DDS, MSEd, FAGD, FACD

Introduction The digital revolution in dentistry of CAD/ The completed design was transferred to
Extensive loss of the human dentition can CAM systems has increased the populari- the printer using Chitubox slicing software.
have a devastating impact on day-to-day ty of the indirect method due to decreased
life. It is the responsibility of the dentist cost, ease of use, and increased speed. How- The printer used was a Phrozen Sonic Mini
to restore the aesthetics and function now ever, most CAD/CAM systems rely on mill- 4k, a LCD type resin 3D printer. The resin
lost. In many cases, indirect restorative ing machines where the dominant method used was SprintRay OnX nanoceramic res-
procedures are required to create a success- of production is subtractive manufacturing. in in B1, and post-processed in FormLabs
ful restoration when there is substantial The following case study aims to investi- Wash and Cure. The produced flat shade
B1 provisional was then tried in the pa-
hard tissue missing. Common issues with gate another indirect approach of provision-
this indirect approach are turnaround time, alization using additive manufacturing (3D tient’s mouth for confirmation of fit and
shade matching (Figure 3).
fit and aesthetics of the temporary (interim) printing) and nanoceramic resin. 4
prosthesis during this time, and cost of the
indirect restoration. The temporary pros- Clinical Example
thesis is vital in achieving a good-quality A 28-year-old male presented to the of-
1
definitive prosthesis. It is responsible for fice with the chief complaint of an anterior
maintaining the tooth position, protecting crown that fractured off during breakfast.
the pulp, maintaining their periodontal re- An examination revealed that #8 crown
lationship, and establishing function and had fractured off and had a failing core
aesthetics. In certain circumstances, pro- with recurrent decay (Figure 1).
visional prostheses are required for longer Figure 3. SprintRay OnX Flat shade B1 tempo-
durations; thus, provisional restorative ma- rary tried-in. Note the monochromatic appear-
terials should have good physical and me- ance of the printed crown.
chanical properties. 1
Characterization
The demand for high-quality aesthetic pro- To impart a polychromatic appearance to
visional and permanent restorations has the printed crown, a variety of flowable
significantly increased in recent years due tints were used. First, a grey tint (Creative
Color gray, Cosmedent, Chicago, Il) was
to improved techniques, materials, and pa- used to impart the appearance of incisal
tient expectations. Therefore, the choice of Figure 1. Preoperative presentation showing translucency (Figure 4). This layer was
fabrication method and material is pivotal. failing restorations and tooth volume loss. cured, then an opaquer (A2-A2.5 Opaquer,
This article will demonstrate an additive The tooth was anesthetized with 2% li- Creative Color) was used to mimic the in-
approach to conventional indirect tempo- docaine with 1:100,000 epinephrine. The cisal halo found at the incisal edge (Fig-
rary crown manufacturing through CAD/ previous core and caries on #8 were re- ure 5). Dentin mamelon characterizations
CAM and 3D Printing. moved. The tooth was etched and bond-
ed. Anchor (Vista Apex, Racine, WI) was
Provisional Fabrication placed, then cured. The core was polished
The provisional restoration is a pivotal and the preparation refined. A double zero
part of fixed prosthodontic treatment and cord (Ultrapak, Ultradent, South Jordan,
should be able to weather oral conditions UT) was packed into the sulcus and both
until the definitive prosthesis is placed. the maxillary and mandibular arches were
When considering provisionalization, the scanned with a Trios 3 CAD/CAM scanner.
dentist faces two crucial decisions: the fab- The generated STL file was uploaded to
rication method and the material of choice. Meshmixer (a free application) and a mir-
It is vital for the provisional of choice to ror image of #9 was designed to the prepa- Figure 4. Gray tint for halo effect.
have adequate strength, aesthetics and pre- ration of #8 (Figure 2).
cise marginal fit as a deficiency in any will
likely require an additional visit. There are
two popular groups of provisional mate-
rials, PMMA/PEMA resins and Bis-acryl
resins, and two fabrication methods, direct
or indirect. 2

A large advantage of the direct method is
speed; however, several drawbacks include
polymerization shrinkage and irritation of
adjacent tissues. 3
Figure 5. Placement of a flowable
Figure 2. Image of design in MeshMixer. opaquer to mimic the incisal halo.
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