Conservative smile enhancement: Direct composite resin restoration of conoid lateral incisors

Fortunately, restorative materials and procedures evolve constantly. If an initial restoration was created using minimally invasive procedures, there should be more tooth structure to work with when a second restoration is needed. The following case report demonstrates such a conservative approach.

Case report

After orthodontic treatment, a 19-year-old female patient was dissatisfied with the unpleasant, disproportional appearance of her conoid maxillary lateral incisors. A direct composite technique was selected for smile enhancement at the initial appointment (Figs. 1–4).

Following enamel-preserving preparation using a tapered, round-ended fine diamond bur and sand-blasting, a celluloid strip was placed subgingivally and fixed using flowable composite. This helped to create the desired emergence profile and contact points. Next, a retraction cord was inserted into the labial part of the gingival sulcus (Fig. 5).

 After isolation of the operative field, the preparation was etched with 37% phosphoric acid for 30 seconds, then thoroughly rinsed and dried. Subsequently, a fifth-generation bonding agent was applied and light cured (Fig. 6).

The next step entailed creating palatal and two lateral enamel walls that were completed using increments of enamel-shade resin. Creating a lingual shelf in this manner left room for the subsequent dentine layering (Fig. 7).

The appropriate dentine-shade resin was then applied in order to create distal and mesial lobes. These were light cured for ten seconds (Fig. 8). Dentine in a darker shade was placed onto the cervical third. Prior to light curing, the white strip was painted horizontally along the incisal edge of the enamel shelf using a white tint and smooth brush (Fig. 9). Finally, an enamel resin layer was placed, contoured, smoothed with a brush and light cured (Fig. 10).

After completion of composite applications and polymerisation, fine flame-tipped finishing diamond burs and Sof-Lex discs (3M ESPE) were used for gross contouring and creating texture. The final polish was achieved using rubber finishers, a brush, a felt wheel and a paste kit (Fig. 11).

The same procedures were followed during reconstruction of the left lateral incisor (Figs. 12 & 13). Figures 14 to 16 show the situation 30 days post-operatively. The lateral incisors show favourable integration of form and colour as achieved through the direct composite resin restoration procedure. Adequate contours and proportions create a smile with harmonious symmetry and a natural appearance.

Some cases present with conoid lateral incisors displaying a lack of gingival harmony, as was the case with this patient (Figs. 17 & 20). This usually manifests as the translocation of the gingival contour coronal to the zenith of the canine and the central incisor. Such a clinical situation requires gingival recontouring before direct restoration.

In the case presented, the recontouring procedure was carried out using a Soft Tissue Trimmer bur (Edenta). Modifications were limited by the patient’s biologic width. As observed at four-week follow-up visits, there was a very good gingival response to the polished restorations (Figs. 19 & 21).

Conclusion

Conoid lateral incisors are not uncommon. They may be found unilaterally or bilaterally. Their poor appearance can spoil an otherwise attractive smile. The case presented describes a minimally invasive way of addressing this problem using direct composite bonding. The step-by-step images illustrate how dentists can solve this cosmetic issue without using aggressive techniques and with the advantage of being in full control of shade matching and characterisation.

This article was published in Cosmetic Dentistry_beauty & science No. 1/2013.