3D Palatal Index for Class IV Composite Restoration

A clinical case by our Community member Dr.Mohammed Shaga

This article and its content are published under the Author’s responsibility as an expression of the Author’s own ideas and practice. Styleitaliano denies any responsibility about the visual and written content of this work.

Mimicking the appearance of the adjacent natural tooth is challenging when restoring a fractured anterior tooth. This clinical article describes a modified index technique for restoring a class IV cavity. A replica of the restored tooth was fabricated with computer-aided design and 3D-printing technology, which precisely mimicked the contralateral incisor.

: fractured central incisor

Fig.1
A male patient, 16 years old, sought care at the dental clinic with fractures of the right maxillary central incisor. The patient had no clinical symptoms during this period.

fractured upper right incisor and x-ray

Fig.2
The right maxillary central incisor had been fractured in the middle third three years earlier, and, in the meantime, caries involved the enamel and dentin. No pulp exposure was reported or found, as well as no clinical signs or symptoms.
A radiographic examination of the right central incisor was conducted and no abnormalities, such as periapical lesion, root resorption, etc. were found.

digital model wax up and index design

Fig.3
A 3D-printed template was fabricated using a silicone impression, lab scan, Exocad software and 3D printing. Firstly, scanning for stone model by lab scan. Then, 3D wax-up of the right central incisor matching all anatomy and details of the adjacent tooth. Last, a palatal guide was designed using the exocad software, and then 3D printed to enable us to transfer the digital wax-up design into the patient’s mouth accurately.

isolation of teeth before caries removal

Fig.4
Isolation with knot ligatures and rubber-dam inversion to achieve clean and dry working field, and minimal interference with the restorative procedures.

: cleaning caries under rubber dam isolation

Fig.5
The adjacent tooth was protected using a sectional matrix during cleaning of caries.

polydentia banner style italiano
polydentia banner style italiano
beveling and edge-rounding with bur and disc

Fig.6
A 1.5-2 mm fine bevel preparation was designed using a yellow-band football diamond bur. The bevel should be as long as the fracture extension and afterwards the finishing of the preparation with coarse and medium abrasive discs.

class IV cavity ready for restoration styleitaliano style italiano

Fig.7
After beveling and rounding of sharp edges, the tooth surface was ready for adhesion.

etching tooth with teflon tape protection style italiano styleitaliano

Fig.8
After shielding the adjacent teeth with teflon tape, selective enamel etching was carried out for 25 second with 37% phosphoric acid.

microbrush bonding cavity

Fig.9
Application and rubbing for 20 seconds of multiple coats of universal bonding agent. Air was the used to carefully thin the bonding before curing for 40 seconds.

fitting of 3d printed palatal index styleitaliano style italiano

Fig.10
The 3D-printed template was positioned after disinfection and its correct fit was checked before proceeding.

composite adaptation on resin palatal index

Fig.11
The enamel shade adapted on the 3D printed index in the tooth fracture area.

brushing composite for palatal build-up styleitaliano style italiano

Fig.12
The 3D printed index was placed back on the anterior teeth to build the palatal wall. A brush was used to adapt the composite to the cavity margin. After removing excess material, light curing was carried out for 20 seconds.

palatal build up before index removal

Fig.13
As you can see, the newly-built palatal wall had the same anatomical features of the adjacent incisor.

unica anterior matrix in place for proximal build-up

Fig.14
The Unica matrix (Polydentia) was used to restore the proximal wall, and to achieve a good seal with the palatal wall. The matrix can be stabilized with a wedge if necessary. In this case, flowable composite was injected in the cervical area and cured to keep the matrix in the desired position.

composite class IV restoration outlined style italiano styleitaliano teeth dentist

Fig.15
After building the proximal wall using the same enamel shade, and the incisal halo by using a dentin shade, the frame to layer the core of the restoration was ready.

finished class IV composite restoration of upper right central incisor

Fig.16
Intraoral post-operative view.

smile after composite restoration of broken incisor

Fig.17
Extraoral post-operative view.

incisal details and texture of composite restoration

Fig.18
Incisal details.

Conclusions

The direct resin composite restoration of maxillary central incisors using a 3D-printed template represents an accurate, convenient, aesthetic and functional option. A 3D-printed template is therefore an acceptable and reliable alternative to traditional protocols in direct composite restoration of maxillary central incisors, including fractured teeth and dental caries.

Bibliography

1. Xia J, Li Y, Cai D, Shi X, Zhao S, Jiang Q, Yang X. Direct resin composite restoration of maxillary central incisors using a 3D-printed template: two clinical cases. BMC Oral Health. 2018 Sep 20;18(1):158.
2. Gao Y, Li J, Dong B, Zhang M. Direct composite resin restoration of a class IV fracture by using 3D printing technology: A clinical report. Epub
2020 Apr 23.
3. Devoto W, Saracinelli M, Manauta J. Composite in everyday practice: how to choose the right material and simplify application techniques in the anterior teeth. Eur J Esthet Dent 2010;5(1):102-24.

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