Materials and methods
A 45-year-old male patient came to the dental office reporting a mild pain during palpation on the maxillary right lateral incisor (No. 7) and maxillary right central incisor (No. 8). During clinical exams, there was no swelling or any visual alteration in the region of the maxillary right lateral incisor (tooth No. 7) and maxillary right central incisor (tooth No. 8 ) (Figure 1A). After the clinical examination, the periapical radiographic exams detected the presence of a periapical lesion involving the previously reported teeth. The cold-thermal pulp test (Roeko Endo Frost, Langenau, Germany; Coltène/Whaledent Inc., Cuyahoga Falls, Ohio, USA) gave a nonvital result for both teeth, and periapical percussion and palpation tests indicated sensitivity.
Root canal treatment was performed with a crown-down technique using rotary system files, and irrigation was performed with 2.5% of sodium hypochlorite (NaOCl) through a 30 gauge needle (NaviTip®) (Ultradent, South Jordan, Utah) coupled to a 5 ml disposable syringe (NaviTip). After the root canal preparation, ultrasonic activation with 17% EDTA and 2.5% NaOCL solutions was performed 3 times for 20 seconds in each tooth.
Afterward, the root canals were dried, and an intracanal dressing with calcium hydroxide paste (Biodinâmica, Ibiporã, PR, Brazil) was used, and the teeth were coronally sealed with Coltosol® (Coltène/Whaledent Inc., Cuyahoga Falls, Ohio, USA) and composite. After 21 days, the intracanal dressing was removed by copious irrigation with saline solution, the root canals were dried, and the obturation was performed using gutta-percha points and AH Plus® (Dentsply Maillefer, Tulsa, Oklahoma, USA) with lateral compaction technique, and the coronal sealing was performed with composite resin.
After 12 months of follow-up, the symptoms disappeared; however, the periapical lesion was not healed (Figure 1B). Thus, the patient was then recommended for endodontic microsurgery. A CBCT (i-CAT™ [voxel dimension 0.2 mm]; Imaging Sciences International, Hatfield, Pennsylvania) was requested due to the dimension of the periapical lesion. The CBCT images showed an extensive periapical lesion involving the mesial portion of the maxillary central right incisor (tooth No. 8) until the mesial portion of the maxillary right canine (tooth No. 6) (Figures 1C and 1D). In addition, substantial bone loss was observed in the buccal-palatal direction without cortical bone loss. In the clinical examination, there was no buccal or palatal swelling.
The decision was made to proceed with endodontic surgery. Fifteen minutes before the surgery, the biochemist specialist collected 35 ml of the patient’s blood to process the PRP. For extraoral antisepsis, 2% chlorhexidine was used and local anesthesia with 3% mepivacaine with epinephrine 1:100,000 (Mepiadre DFL). The incision procedure was performed with a micro blade No. 67, and a full-thickness mucoperiosteal triangular flap was reflected at the base of the papillae, extending from the maxillary right central incisor to the left maxillary right canine. The vertical incision was placed on the distal side of the right maxillary canine.
There was no cortical bone loss; thus, the osteotomy was performed with a slow-speed spherical bur under copious saline solution irrigation. The periapical lesion was completely enucleated, and the granulation tissue was sent to histopathology. The apicectomy was performed on the maxillary right lateral incisor (tooth No. 7) and the maxillary right central incisor (tooth No. 8) with drill 699 under saline irrigation. A retrograde cavity preparation of the teeth was done with 5 mm of extension using a Berutti ultrasonic tip (EMS [Electro Medical System], Switzerland). The surgical cavity and the root canals were placed with methylene blue 0.005% (DMC Brazil; DMC USA, Plantation, Florida), and photodynamic therapy was applied. The methylene blue was removed with copious saline solution irrigation, and the canals were dried with sterile paper points and retrofilled with Sealapex™ sealer (Kerr Dental, Orange County, California) mixed with MTA (ProRoot® MTA, Dentsply Maillefer, Tulsa, Oklahoma, USA) (Figure 2A).
To prevent an undesirable fibrous repair, the PRP was mixed with hydroxyapatite nanoparticle + Lactic acid-co-glycolic acid (PLGA) (DMC Brazil; DMC USA, Plantation, Florida), and the surgical cavity was completely filled (Figure 2B). In order to protect the filling material, a membrane of platelet-poor plasma (PPP) was used on top of it (Figure 2C). The flap was repositioned after incising the periosteum at the base of the flap to obtain tension-free closure, and a suture was performed with VICRYL® 6.0 (Ethicon) (Figure 2D). For all procedures, a range of 3x to 25x magnification was used.
The histopathology results confirmed the presence of a radicular cyst. The clinical and radiographic assessment 5 years postoperatively confirmed a stable outcome (Figures 3A and 3B). CBCT showed the presence of the bone graft filling the surgical cavity (Figures 3B and 3C). The tissue appeared well integrated, and a similar radiopaque and granular is compared with the adjacent bone.