An extraoral and intraoral cleansing with 0.12% chlorhexidine was done to lower surface bacterial load, and local anesthesia was performed with 4% articaine (1:100,000 epinephrine). A full-thickness intrasulcular rectangular flap was reflected, made with two vertical incisions extending from the maxillary right lateral incisor to the maxillary left canine by the means of a No.15c blade scalpel (Figure 5). During the surgical procedures, the presence of a bone defect in the buccal plate was observed, being used for making the ostectomy with the aid of chisels (Lucas-Triangular, Wedelstaedt, Ochsenbein/Millenium-Golgran, São Caetano do Sul, Brazil), under copious irrigation with sterile saline.
A curettage of the exposed area was executed, as well as the instrumentation of the root canal, made with K-files under copious irrigation with sterile saline. The root canal filling was performed with gutta-percha and AH Plus® endodontic sealer (Dentsply, Detrey, GmbH, Germany), using Tagger’s hybrid obturation technique. For this purpose, a master cone and two accessory gutta-percha points (XF, Dentsply Maillefer USA, Oklahoma) were placed into the root canal while performing an initial lateral compaction. Afterward, a gutta-percha condenser (No. 80, Dentsply Maillefer, Ballaigues, Switzerland) was coupled to a low-speed contra-angle handpiece and passively placed into the root canal. The gutta-percha condenser was inserted 5 mm short of the working length next to the gutta-percha cones, being activated for 3 seconds. The condenser was removed from the root canal with the contra-angle handpiece still operating while maintaining gentle pressure against one of the root canal walls. Finally, an apical plasty with the aid of an apical file (Bramante, Golgran, São Caetano do Sul, Brazil) was performed with the purpose of removing areas of roughness and smoothing the surface of the root apex.
Simultaneously, a periradicular curettage was executed on the left lateral incisor in order to remove the pathologic tissues surrounding the tooth (Figure 8). Lastly, an apical plasty was performed.
Both surgical cavities were disinfected through photodynamic therapy (MMOptics, São Carlos SP, Brazil / λ= 660 nm, P = 40 mW for 3 min, E = 7.2J) using methylene blue (Chimiolux DMC, São Carlos SP, Brazil) as a photosensitizer10 (Figure 6). Subsequently, the surgical cavities were filled with calcium sulfate (Figure 9), and the suture was done. Clinical and radiographic controls were made. Twelve months after the surgery, new bone formation could be observed radiographically, and the patient was asymtomatic (Figures 7 and 10). In the same way, cone beam computed tomography (CBCT, i-CAT™, Hatfield, Pennsylvania) images were acquired, confirming the healing of the periapical tissues, 2 years and 8 months after the surgery (Figures 11 and 12).
Results and discussion
As described by Velvart,14 the main objective of surgical treatment is to provide conditions for the healing and repair of the periradicular tissues, which is also the focus of conventional endodontic therapy.
Periradicular surgery involves a strict treatment planning and factors that should be analyzed carefully. According to different authors,2-5,7 an extensive clinical and radiographic analysis of the patients should be performed, including blood tests in order to study the case and proceed to treatment planning. Hence, anatomical structures, the presence of a periradicular lesion, and the teeth involved should be considered. Before surgery, all the potential risks should be explained to the patient in order to have his/her informed consent for all the needed procedures.2,4 Therefore, it is essential to treat the patient and not just the teeth.4
As reported by some authors,3,5,7 the selection of the flap design has an important influence under different aspects during the steps of the surgery, such as the visibility, anatomical structures, repositioning, suturing, and postoperative care. The incision chosen for this case was a full-thickness intrasulcular rectangular flap because it promotes an excellent access to the operative area. Hence, this flap design has been recommended because of its clinical advantages.2,3,7,14 Certainly, because of the variety of clinical conditions, the selection of flap design should always be made based on every individual case.14,15 It is essential to preserve epithelial and connective tissue attachment at its original level and minimize trauma during the surgical procedures in order to maintain the attachment level.16,17 For this reason, it is crucial to maintain the integrity of the papilla during restorative and surgical procedures because of the difficulty to predictably correct its height.14,17 The papilla base incision (PBI) consists of a shallow incision at the base of the papilla and a second incision directed to the crestal bone, creating a split thickness flap in the area of the papilla base.16,17 This technique has been suggested to prevent loss of interdental papilla height.16,17 However, it could be infeasible in cases where an attachment loss condition such as gingival recession is already present, as observed in this case. Some authors, have described simultaneous filling of the root canal as a useful technique in cases with an uncertain prognosis related to the presence of persistent exudate3,7,18 as well as in cases with the presence of apical resorption. This alternative has also been indicated in cases of teeth with open apex, extrusion of filling materials, anatomical variations, presence of intraradicular retainers, perforations, persistent periapical lesions, or fractured instruments within the root canal.3,19-20
Figures 5-10: 5. Full-thickness flap divulsion. 6. Disinfection of the surgical cavity with PDT. 7. Radiographic follow-up of the right central incisor (12-month control). 8. Clinical aspect of the left lateral incisor after curettage. The presence of a bony defect surrounding the tooth and apical root resorption were observed (arrow). 9. Filling of the surgical cavity with calcium sulfate. 10. Radiographic follow-up of the left lateral incisor (12-month control
According to some authors,2,4,14 peri-radicular surgery success rates have significantly evolved over the past few decades, with the improvement of retrofilling materials, ultrasonic preparation, and the use of magnification during the endodontic procedures. Periradicular surgery also offers the opportunity to retrieve tissue for histologic and microbiologic analysis,2 contributing to the diagnosis. Nevertheless, Lieblich2 explains that in cases with an expected poor success rate, such as the presence of severe periodontal bone loss with furcation involvement, the decision to extract the tooth and place an implant may be a more efficient and predictable procedure.
PDT has been studied as a promising approach to eliminate endodontic microflora.8-9, 21 In a clinical study, Juric, et al.,22 randomly selected 21 patients with endodontically treated teeth with chronic apical periodontitis in order to analyze the antimicrobial efficacy of PDT as an adjunct to conventional endodontic retreatment. Their results showed that the combination of conventional endodontic retreatment and PDT was more successful in the eradication of both gram-positive and gram-negative bacteria species as well as facultative anaerobes and obligate anaerobes when compared to retreatment alone. Therefore, photodynamic therapy could be used as an adjunct to conventional endodontic treatment. In addition, photo- dynamic therapy has been used during surgical endodontic treatment, showing promising results. Garcez, et al.,10 applied an aqueous solution of methylene blue and a diode red laser (λ= 660 nm, P = 40 mW for 3 min, E = 7.2J) in 22 patients undergoing periradicular surgery. The authors concluded that PDT associated with periradicular surgery showed superior results of microbial reduction when compared with other studies in which PDT was associated with conventional endodontic treatment.
Repair after periradicular surgery results in the formation of new tissue, involving cells and structures with the ability to react differently from the original ones. Regeneration consists of the replacement of the previous existing tissue by a new tissue identical to the former in cell composition, structure, and reactivity, implying the formation of new attachment structures.23 Because of the limitations regarding autogenous bone grafting, bone substitutes could be used to enhance osseous healing.24 The placement of calcium sulfate as a filling material in periradicular surgery has been studied by some authors,23,24 showing different results. Murashima, et al.,25 evaluated histologically and morphometrically under light and fluorescence microscope, the effect of calcium sulfate on various osseous defects in beagle dogs’ teeth undergoing apicectomy. The authors concluded that the use of calcium sulfate was effective in bone regeneration on both large osseous defects and “through-and-through” osseous defects. On the other hand, it was less efficient in defects communicating with the gingival sulcus, confirming the presence of new bone completely filling the osseous defects after 16 weeks. In addition, Pecora, et al.,23 demonstrated that the addition of calcium sulfate as a bone graft during conventional surgical treatment of through-and-through lesions improves the clinical outcome. According to the authors, further histological analysis should be done to investigate the quality of the tissues observed after the surgical procedures. In contrast to these findings, Apaydin and Torabinejad,25 found that the placement of calcium sulfate in osteotomy sites after periradicular surgery did not significantly affect alveolar healing.