Apical periodontitis (AP) is a localized inflammation that induces the destruction of periradicular tissues, that is, the periodontal ligament and alveolar bone around the root apex.1 It generally occurs from damage to the dental pulp as a sequela of endodontic infection, physical trauma, or iatrogenic trauma. AP does not heal by itself; however, periapical tissue has the ability to heal if the cause of inflammation is eliminated. Therefore, AP treatment involves elimination of the microbial infection from the root canal and prevention of reinfection. This type of nonsurgical endodontic treatment is often preferred; however, nonsurgical treatment can fail for various reasons.2,3 The common factors affecting endodontic treatment failure include persistent bacterial infection, inadequate filling of the canal, leakage from improper sealing, an untreated canal, iatrogenic procedural errors, and complications from instrumentation.4,5
Surgical endodontic treatment is considered in the case of conventional endodontic treatment failure, root fracture or perforation, and endodontic-periodontic complications.6 Apical surgery is considered in the case of endodontic failure; however, several factors may lead to its failure, which may limit its indication.7 Furthermore, differences in opinion exist among clinicians regarding treatment planning for a tooth with an endodontic failure and questionable prognosis.8 Although this decision might be controversial, it should be based on the prognosis, cost-effectiveness, and patient's preferences.9 Many cases of endodontic failure with persistent infection may ultimately result in tooth extraction.10 Recently, placement of a dental implant has become widely acceptable for endodontic failure, and this treatment option is supported by high survival rates.10 In general, after removal of the compromised tooth, the extraction socket is allowed to heal for several months.11 Infection at the site of implant placement has been considered a contraindication because the presence of infection can compromise osseointegration. Immediate implant placement (IIP) is a well-known useful technique that reduces the number of surgical procedures and shortens the treatment duration,12,13 and many studies have shown that when appropriate protocols are employed, IIP can be used at periodontally or periapically infected sites.14–19 In the case of endodontic failure, IIP is a considerable treatment option with intact surrounding alveolar bone; furthermore, implantation in periapical pathosis is more successful than that in periodontal infection.14 However, many clinicians hesitate to perform IIP in the presence of an existing bone infection.17
In this report, 3 cases of IIP in teeth with endodontic failure and active inflammatory pathosis have been described. Furthermore, consideration of IIP as an efficient treatment modality and the effects of a periapical lesion on implant success have been discussed.
Herein, 3 cases have been described in which IIP was performed for endodontically compromised teeth. The patients had noncontributory medical histories and presented with a buccal sinus tract connected to a periapical lesion; these patients were referred for tooth extraction by the Department of Conservative Dentistry, Seoul National University Dental Hospital (SNUDH), Seoul, Korea. Minimally traumatic tooth extraction was performed under local anesthesia (lidocaine HCl 2% injection [1:100 000], Huons, Seongnam, Korea), followed by meticulous debridement of the socket, and thorough cleaning with sterile saline (0.9% sodium chloride). IIP was performed with good primary stability and filled the gap between the implant and bone with deproteinized bovine bone mineral containing 10% porcine collagen (Bio-Oss Collagen, Geistlich Pharma AG, Wolhusen, Switzerland) and collagen filler (TERUPLUG, Termo Co, Tokyo, Japan). The Seoul National University Dental Hospital Institutional Review Board approved the use of patient records (ERI16006). All participants received an explanation of the study and signed an informed consent form.
The Department of Conservative Dentistry referred a 37-year-old woman, diagnosed with endodontic failure in a mandibular molar, for tooth extraction and implant placement (tooth #30). Radiographic examination revealed a periapical lesion on tooth #30 (previously treated endodontically); the mesial root was suspected to be fractured (asterisk, Figure 1a). Intraoral examination of the patient revealed a moderate probing pocket depth (PPD) of 3–5 mm and showed a buccal sinus tract connected to the periapical lesion (arrow, Figure 1b). The tooth was extracted with minimal trauma, and the extracted tooth showed a preserved alveolar septum and surrounding bone and gingiva (Figure 1c). Next, granulation tissues at the apical site were meticulously debrided, and the extraction socket was thoroughly cleaned with sterile saline (0.9% sodium chloride). Then, the implant fixture (Osstem USII; 4.5 mm in diameter × 10 mm in length, Busan, Korea) was placed in the extracted socket, supported by the bony septum (Figure 1d). The implant insertion torque was 30 N, and the implant stability quotient (ISQ) was measured with a resonance frequency analysis device (Osstell Mentor, Ostell AB, Göteborg, Sweden), which showed a stable ISQ over 60. Then, the healing abutment (5.0 mm in diameter × 3.0 mm in height) was connected to complete the single-stage procedure (Figure 1e). To preserve the bone volume during the socket-healing procedure, the gap was filled between the bone and implant with deproteinized bovine bone mineral with Bio-Oss Collagen and TERUPLUG (Figure 1e). Then, figure-of-eight suturing (Figure 1f) was performed, and the stitches were removed after 10 days. A periapical radiograph shows a stably installed implant using the septum and apical bone (Figure 1g). Three months later, an implant prosthesis was installed after confirmation of full osseointegration of the fixture with an ISQ value over 70. After the treatment, the patient was periodically followed up at 1, 3, 6, 9, 12, 15, and 25 months. Although a clinical examination showed reduced buccal bone, no complication related to the pre-existing periapical lesion was found (Figure 1h). Radiographic examination showed a stable state of implantation during the 25-month periodic-recall follow-up period (Figure 1i).
The Department of Conservative Dentistry referred a 60-year-old man, diagnosed with endodontic failure in a mandibular molar, for tooth extraction and implant placement (tooth #19). The patient stated that he underwent treatment on tooth #19 at a local dental clinic 3 years ago, but it caused him continuous discomfort accompanied by a cyclic buccal blister-like formation. Clinical examination revealed a sinus tract associated with the mesial root of tooth #19 (arrow, Figure 2a). On the periapical radiograph, the apical lesion, incomplete endodontic treatment, and long post are evident, proving endodontic failure (asterisk, Figure 2b). The tooth was extracted with minimal trauma through a root separation (Figure 2c and d). This was followed by meticulous debridement of granulation tissues at the apical site and thorough cleansing of the extraction socket with saline. The implant fixture (Osstem USII; 5.0 mm in diameter × 10 mm in length) was then placed in the extraction socket (Figure 2e). An insertion torque of 30 N was applied and primary stability was observed. Then, the healing abutment (6.0 mm in diameter × 3.0 mm in height) was connected during the single-stage procedure (Figure 2f). Finally, the gap between the bone and implant was filled with deproteinized bovine bone mineral (Bio-Oss Collagen) and TERUPLUG, and simple interrupted suturing was performed (Figure 2f). A periapical radiograph shows that the implant settled well using the septum and apical bone (Figure 2g). The stitches were removed 2 weeks later, and 1 month after the treatment, the gingiva showed good healing around the healing abutment (Figure 2h). Three months later, the implant prosthesis was installed after confirming full osseointegration of the fixture. After the treatment, the patient was recalled periodically at 1, 3, 6, 9, 12, 18, and 24 months. During the follow-up period, no complication related to the pre-existing periapical lesion was found, and radiographic examination revealed a stable state of implantation during the 24-month periodic-recall follow-up period (Figure 2i).
A 63-year-old man visited the Department of Periodontology, SNUDH, with a chief complaint of discomfort in the anterior maxillary teeth. A four-unit bridge comprised tooth #7 and tooth #10, and we speculated a root crack or fracture showing moderate tooth mobility and a buccal sinus tract connected to a periapical lesion at tooth #7 (arrow, Figure 3a). In consultation with the Department of Conservative Dentistry, the patient was diagnosed with a combined periodontic-endodontic lesion and a poor prognosis. Considering the long-term prognosis and cost-effectiveness of tooth extraction, it appeared to be a better choice. The four-unit bridge was extracted, and the socket well was debrided and irrigated with saline. Buccal bone defects were observed in both extraction sockets (Figure 3b). The tooth was extracted with minimal trauma (Figure 3c). Then, internal-type Luna implants (3.5 mm in diameter × 10.0 mm in length, Shinhung, Seoul, Korea) were placed in #7 and #10 sites (Figure 3d) and guided bone regeneration was performed with Bio-Oss Collagen and TERUPLUG (Figure 3e). Thus, the implant was successfully implanted at the anterior maxillary sites despite periapical and periodontal infection (Figure 3f). The periodontal tissue healed well, and inflammation did not recur (Figure 3g). Implant prosthesis was installed 3 months after implant placement. Good maintenance of the gingival architecture and alveolar ridge was observed during the 30-month follow-up period after prosthesis delivery (Figure 3h and i).
In this report, 3 IIP cases of active pathologic conditions with apical periodontitis have been described. Many studies have supported the hypothesis that IIP trials at an infected site with endodontic or periodontal lesion show a high survival rate.19 Notably, the following points are of concern: (1) the protocols used to address infection prior to IIP, (2) the possibility of osseointegration failure in the presence of infection, and (3) whether IIP is more effective in preserving the alveolar ridge than delayed implant placement (DIP). Considering the aforementioned concerns, traditionally, many clinicians have preferred to allow the ridge to heal for several months, while the patient might be subjected to the inconvenience of a missing tooth. In consideration of the first concern mentioned above, attention was focused on thorough debridement and cleansing after tooth extraction and used medications, including an antibiotic (cefdinir) and anti-inflammatory analgesic (aceclofenac), to reduce the possibility of reinfection after IIP. However, the benefits of antibiotic administration in such conditions remain unclear.19 Regarding the second concern, although the cases in the present study are limited to approximately 25 months of follow-up, no difficulty was noted in the maintenance of osseointegration despite the pre-existing infection. If an apical pathologic condition influences osseointegration, it might result in early implant failure.20 Implant failure is classified on the basis of its timing.21 Early implant failure occurs before or at abutment connection; late failure occurs after occlusal loading. Early implant failure occurs because of a disturbance when establishing osseointegration and interference during the healing process; the late implant failure is due to difficulty in maintaining the established osseointegration.22,23 Thus, the risks of implant failure in IIP and DIP appeared similar at an early stage of osseointegration. Moreover, regarding the third point of concern, dimensional alteration of the alveolar ridge, including a horizontal or vertical change, occurring in the extraction socket is well known.24,25 To minimize this phenomenon, clinicians introduced a ridge preservation technique using a biomaterial or IIP.26,27 Some studies have suggested that IIP preserved alveolar bone width and height from sequential bone resorption after tooth extraction28–30 ; however, other studies contradicted this finding, and showed that IIP was not a feasible treatment option for ridge preservation and that no statistically significant difference existed between IIP and delayed implantation.31,32 Despite the debate regarding whether IIP is advantageous in preventing alveolar bone resorption, the 3 cases reported in this study showed slight alveolar bone resorption, indicating that IIP does not assure ridge preservation. IIP promotes reduced treatment time and surgical extent; however, it is not always advantageous. In addition to concerns about reinfection (as observed in the patients in this study and in each clinical experience), IIP might cause some difficulty in positioning the implant at an accurate ridge site because of uneven extraction socket conditions. In the cases in this study, an attempt was made to place the implant in the center; however, it was slightly sided to the root sites (Figures 1 and 2). In this way, IIP can induce incongruity in the implant prosthesis related to the parafunctional occlusal force.33 Attention to placement of the implant in the center is necessary for optimal occlusion loading. The presence of a sound interseptal bone in the multirooted molar is an important factor for the initial stabilization of the implant; therefore, atraumatic tooth extraction and initial drilling to engage the implant at the interseptal bone is a key step for a successful IIP.34 However, resistance to push the fixture out from the dense bone to the socket space will hinder the proper positioning of the implant in clinical settings. In unavoidable cases where the implant is installed in the off-center position, prosthetic compensation would be needed for long-term success. Conventionally, IIP is performed at a greater depth and at a lingualized or palatalized position to compensate for unavoidable horizontal and vertical alveolar resorptions, which can be risk factors for unbalanced occlusal loading.
Based on this report, IIP could be considered one of the treatment options in an infected site; however, more clinical studies with longer follow-up are needed to confirm this procedure as a reliable treatment. This treatment modality can minimize dental visits, treatment duration, and stress caused by a missing tooth.
This research was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (HI14C2681).
The authors report no conflicts of interest.