Dens in dente type III (Oehlers)

By Dr Jörg Schröder

CASE DESCRIPTION

This is a case of a 23-year-old male patient in generally healthy condition. For two to three weeks, the patient suffered from labial pain on tooth 22 upon palpation. There was also a small labial swelling at the apical region.

However, during the first consultation, labial fistular opening was not found.

Tooth 22 was slightly sensitive to percussion, axially and laterally, but not hypermobile. The probe depths were within physiologic
limits. The sensitivity test to cold and electric stimulus (Elements Diagnostic, Sybron Endo, Orange, US) were reproducibly positive. Trauma could be excluded with respect to the general anamnesis.

To clarify the course of the invagination in the general area and planning the practical treatment, a CBCT was performed in addition to two-dimensional x-ray diagnostics.

RADIOGRAPHIC EXAMINATION

Individual digital images revealed soft tissue density, sharply delineated translucence at the distal and lateral side of the apex; and enamel density, shadowing in the mesial area of the crown extending to the medium third of the root. Presumably, dens in dente type III (Oehlers).

Sharply delineated translucence of soft tissue density at the apical and distal side of tooth 22, clear-cut separation between pulp cavity and invagination, apical, kidney-shaped tapering of root transverse cross-section on tooth 22, and significant reduction of labial osseous lamella was also found.

TREATMENT

Tooth 22 was diagnosed to have a vital pulp with symptomatic chronic apical periodontitis.

The treatment was conducted unilaterally:
• Thorough drying
• Preparation of the enamel invagination by means of cleaning with powder blaster: PROPHYflex with PROPHYflex powder (sodium carbonate)
• Preparation of the access cavity with diamond instrument

The pre-operative CBCT scan showed clearly that the communication to the apical periodontium did not come from the deepest point of the invagination, but diverged disto-palatally somewhat above.

After measuring the distance from the incisal edge to the opening of communication and slightly expanding the primary access cavity, it was possible to insert a pre-bent hand instrument (size ISO 008) into the branch to the periodontium and advance to the apical tip of the invagination under endometric control (Morita Root ZX).

The apical parts, which were clearly bent disto-palatally, were prepared mechanically with pre-bent ProTaper hand instruments (S1- F2) after repeating the endometric measurement several times.

After extensive ultrasound-supported irrigation with NaOCl 5%, EDTA 17%, and subsequent rinsing with 70% ethanol, the canal was dried with sterile paper tips and the obturation was performed in a modified Schilder technique with AH26 and gutta-percha sealer. The coronal part of the obturation was performed with Squirt technique.

After a radiological control exam, a quartz-fibre pin was inserted in the lower two thirds of the invagination. Then, the dentin-adhesive obturation was completed with a dual-curing composite.

The coronal part of the access cavity was sealed with a light-curing hybrid composite. The first clinical follow-up took place after one year. Tooth 22 showed no clinical symptoms. Radiological scans showed that the apical translucence was healing. However, it had not healed completely yet. In view of the expansion of the periapical lysis determined in the pre-operative CBCT, this could hardly have been expected. Under certain circumstances, we may have to revise our ideas of radiologically-certain healing with the advent of CBCT, or at least adjust the time spans as tooth 22 still responded reproducibly to cold and electric stimuli.

(Images taken with Veraviewepocs F40 made by Morita, FOV 4×4 cm, rotation time 9.4s, 80Kv, 6mA)

About the Author

Dr Jörg Schröder graduated from the Free University of Berlin, Germany, in 1988. A specialist in endodontics and member of various international dental society, he runs an endodontic private practice and has recently authored a dental video journal: Ergonomics at the dental microscope. In 2013, he won the Peter-Gulden Practitioner Award for Endodontics and has served as vice regent, ICD, District 6, Germany, from 2014-2020.

This article was published in Dental Asia March/April 2021 issue.