Patient: 9 year-old male in excellent health (9/8/2016)
Chief Complaint: Tooth pain associated with the maxillary left lateral incisor (#10)
Dental History: The patient had received no recent relevant dental treatment and was referred to the author by a pediatric dental specialist.
Significant Findings: The patient presented with a “peg-shaped” maxillary lateral incisor. The radiographic findings suggested a Type 3 Dens Invaginatus root form which was confirmed with a CBCT scan. The patient also demonstrated an immature root apex with a diffuse radiolucency consistent with the developing apical papilla and/or possibly a dental abscess. Moderate sensitivity to percussion was elicited. Cold thermal stimulation and and electric pulp test failed to yield a response. There was no observable swelling and all other findings were within normal limits.
Pulp and Periradicular Diagnosis: Infected dens component and questionable pulp vitality (likely vital due to the blunderbuss apex form)
Treatment Prognosis: Good
Treatment Plan: Conservative treatment of the dens in two steps with interim calcium hydroxide then dens filling to allow for apexogenesis.
Special Considerations of Performed Treatment:
Dens Invaginatus is a relatively rare dental anomaly commonly affecting maxillary lateral incisors. A Type 1 Dens Invaginatus form is the simplest involving a shallow lingual pit that is prone to caries requiring a filling. The Type 2 variation consists of a deep dens component with a long tube and a blind apical closed end. This presented case represents the Type 3 variant which is the most complicated form. Both the coronal and apical ends of the dens canal are patent, contiguous with the periodontium, and lined with an enamel layer.
Similar to a root with a necrotic pulp, the dens tissue can become necrotic and infected leading to an apical abscess. In a mature tooth with an infected dens the diagnosis is simpler because the pulp will tend to be sensitive to cold and electric testing. An immature root with an open apex is more difficult to test because thermal and electric testing is less reliable. It should be presumed that the pulp is vital because the open apex allows excellent circulation and there is a greater chance of recovery from a severe inflammatory stimulus like caries or trauma.
9/13/2016: Treatment of the dens was begun with a discrete access at the peg lateral cusp peak. The penetration point was relatively simple to determine because of the circular layer of enamel directing access as a target to the dens space. Shaping was kept discrete and narrow to minimize the chance of exposing and irritating the presumed vital pulp which enveloped the invaginating dens. There was no bleeding when entering the dens space tending to validate the hypothesis that the dens contained no vital tissue. Calcium hydroxide was placed in the canal space and the access was sealed with a Cavit temporary filling.
10/11/2016: The patient presented without symptoms and the percussion sensitivity and pain had resolved. The temporary filling was removed and the calcium hydroxide was flushed out with sodium hypochlorite. The dens was filled with gutta percha lined with EndoSequence bioceramic sealer, next a shallow Cavit base, and a bonded resin filling was placed in the access (Photobond/Filtek).
Recall:
9/17/2018: The patient returned for his 24 month recall examination one month early. Complete root formation was noted with root end closure and significant reduction of the periapical radiolucency to apical periodontal ligament space widening. The patient was asymptomatic with no evidence of recurrent disease.
Key Learning Points:
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Dens Invaginatus is a root anomaly that requires special understanding and management.
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Pulp tests are unreliable with an immature root apex.
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Avoid removing the pulp of a developing root.
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Even in the presence of an abscess the stem cells of the apical papilla (SCAP) have the potential for apexogenesis.
- Setting up decision points during treatment allows treatment validation so that the proper course can be continued or changed.