PMC8443381_01
The initial periapical radiography and the axial section of CBCT scans of the teeth #24 and #25.
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Cone-beam computed tomography "CBCT" scans confirmed the findings of the periapical radiography and revealed the presence of radiolucent lesions surrounding the apex of both teeth #24 and #25 (Figure 1).
Clinical images and periapical radiographs of the retreatment of tooth #24. (a) Access cavity; (b) bleeding perforation; (c) exploring the palatal canal; (d) gutta-percha removal from the perforation; (e) collagen sponge placement; (f) 5MO cement application; (g) radiography of palatal canal localization; (h) cleaned perforation site; (i) radiography of 5MO cement application; and (j) radiography of obturation.
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After rubber dam isolation and under microscopic magnification by SmartOptic dental microscope (Diplomat Dental, Piestany Slovakia), the access cavity was performed through the full-ceramic crown using a straight fissure diamond bur until 5 mm of depth and before reaching the furcation area (Figure 2(a)). Once the perforation was uncovered, a considerable amount of bleeding came out (Figure 2(b)). Petropolis, RJ, Brazil) (Figure 2(c)). Periapical radiography confirmed the detection of the lingual canal (Figure 2(g)). The temporary filling was removed, and the Ca(OH)2 dressing was washed away using sterile saline solution irrigation; then, the Zumax micro tweezer (Zumax medical, Suzhou New District, China) was used to catch and remove the obturation material (gutta-percha) from the perforation site (Figure 2(d)). Periapical radiography confirmed the removal of all foreign bodies from furcation perforation (Figure 2(h)). Then, a collagen sponge was packed inside the furcation perforation to form a matrix (Figure 2(e)), and the 5MO silicate-based cement (Golden Yatti LLC Muscat, Oman) was applied using the microapical placement system "MAP" (Dentsply Tulsa, Switzerland) over the collagen matrix to seal the large perforation site (Figure 2(f)). The obturating material was removed using D3 retreatment rotary file (Dentsply Maillefer, Sao Paulo, SP, Brazil) at a 300 rpm rotation speed associated with NaOCl 5.25% irrigation (Figure 2(i)). Then, the canals were dried with paper points 25.06 (Dentsply Maillefer, Sao Paulo, SP, Brazil) and obturated using the single cone technique with a 25.06 gutta-percha cone (Dentsply Maillefer, Sao Paulo, SP, Brazil) and bioceramic sealer (CeraSeal, Meta Biomed, Colmar, PA, USA) (Figure 2(j)).
Clinical images and periapical radiographs of the retreatment of tooth #25. (a) Access cavity; (b) bleeding perforation; (c) 5MO cement application; (d) radiography of 5MO cement application; (e) radiography of cleaned and prepared canal; and (f) radiography of obturation.
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Again, the same steps were followed, until reaching the fiber post (Figure 3(a)); however, while removing it with the ultrasonic tip ET20, the fiber post was pushed out into the drill post (lateral) perforation because the fiber postpreparation extends out of the root canal in a distal direction (Figure 3(d)). Later, the fiber post was removed (Figure 3(b)) using a long and narrow endo probe with the aid of ultrasonic tip ET25 (Acteon, Indaiatuba, SP, Brazil) associated with copious irrigation of the perforation site. The perforation site, measuring around 3 x 3 mm, was sealed using 5MO silicate-based cement (Figure 3(c)), without a collagen sponge application. The cement did not overextrude, and this was confirmed radiographically (Figure 3(e)). The same steps were followed again for retreating and obturating the single root canal of tooth #25 (Figure 3(f)).
Periapical radiography and CBCT image after a 3-year follow-up.
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Radiographically, healed periapical and lateral lesions were noticed, and a bone neoformation was observed (Figure 4(a)). The patient was advised to retreat the upper adjacent molar as a radiolucent lesion was detected (Figure 4(b)).