PMC5426152_01
Preoperative images: (a) Intraoral, (b) Type II dens invaginatus in 34, (c) occlusal radiograph showing (d) panoramic radiograph, (e) axial view in cone-beam computed tomography image, (f) three-dimensional reconstruction of mandible, and (g) coronal cone-beam computed tomography section
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F1
The mandibular first premolar had a slightly greater mesiodistal width, normal color, normal gingival tissues, and probing depth [Figure 1a]. Radiographic examination [Figure 1c and d] showed an extensive multilocular radiolucency causing severe hollowing out and weakening of the body of the mandible. A Type II dens invaginatus was observed in 34 [Figure 1b]. Cone beam computed tomography (CBCT) examination [Figure 1e-g] revealed a complex invagination in coronal third of first premolar on mesiolingual aspect close to the external root surface.
(a) Working length, (b) mineral trioxide aggregate apical plug, (c) fiber postcoated with foil, (d) fiber reinforced composite build up, (e and f) postobturation intraoral periapical, (g and h) 6 months recall, (i) metal ceramic crowns placement, (j) 3 years recall radiograph
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F3
Cleaning and shaping of 35 and 36 was done with crown down technique 5.25% sodium hypochlorite (NaOCl) as irrigant and obturated with cold lateral condensation [Figure 3f]. Elimination of the dead pulp space in the invaginated mandibular premolar [Figure 3a] resulted in significant weakening of the remaining root. Mineral trioxide aggregate was placed in the apical third using sonic activation (EndoActivator, Dentsply Maillefer, Switzerland) and temporized [Figure 3b]. Radix fiber post no. 5 (Radix Fiber Post, Dentsply Maillefer), covered with aluminum foil and held passively in the center of the canal with locking tweezers [Figure 3c]. The bonding agent and resin cement were light cured for 60 s through the post [Figure 3d and e]. Six-month follow-up showed significant healing of the periapical lesion [Figure 3g and h]. The endodontically treated teeth were asymptomatic and restored with metal ceramic crowns [Figure 3i]. Recall at 3 years shows excellent healing of the periapical lesion and asymptomatic involved teeth with no evidence of any root fracture [Figure 3j].