Selective Dual Apical Surgery for Adjacent Immature and Mature Upper Incisors With a Large Periapical Lesion: A 4‐Year Follow‐Up Case Report

ABSTRACT

Conservative dual apical surgery without conventional orthograde root canal treatment, as well as root‐end resection/preparation/filing/sealing, can successfully manage large periapical lesions involving adjacent immature and mature teeth. This hypothesis‐generating observation suggests bioactive root‐end filling may reduce treatment burden in carefully selected cases, but further studies are needed.

1. Introduction

Apical periodontitis, particularly in teeth with complex anatomy or incomplete root development, remains a substantial clinical challenge owing to diagnostic limitations, anatomical complexities, and the need for biologically compatible treatment strategies [1, 2]. For immature permanent teeth, traditional apexification using long‐term calcium hydroxide or single‐visit apical plugs with biomaterials like mineral trioxide aggregate (MTA) are established treatment approaches [3, 4]. However, these approaches may be technically demanding, time‐consuming, and prone to failure, necessitating complex retreatment strategies [5].

For non‐vital mature teeth with apical periodontitis, orthograde root canal therapy (RCT) is conventionally used to eliminate intraradicular infection [2, 5, 6]. When orthograde retreatment is not feasible or has failed, apical surgery with root‐end resection/preparation and root‐end filling/sealing is indicated [6]. A key challenge is accurately determining pulpal vitality in teeth with large periapical lesions, since conventional sensibility tests are equivocal and do not reflect vascularity, complicating decisions [7, 8].

The concurrent presentation of apical periodontitis in adjacent immature and mature teeth is uncommon. It may require different treatment pathways: regenerative endodontic procedures or an apical plug (i.e., apexification) for the immature tooth, and orthograde RCT for the mature tooth. Such cases may therefore benefit from individualized strategies that address the source of periapical disease while preserving tooth structure [9, 10].

This case report presents the 4‐year outcome of a conservative dual surgical approach for an immature central incisor with a failed apical plug and an adjacent mature lateral incisor with untreated apical periodontitis, using apical revision and primary apical surgery without root‐end resection or orthograde (re‐)treatment. The case provides a hypothesis‐generating observation on selective apical management in an unusual clinical setting. This report adheres to the CARE guidelines [11].

2. Case History and Examination

A 14‐year‐old female was referred to our clinic with a chief complaint of acute pain/tenderness in the right maxillary anterior region. Her medical history was unremarkable. She was in the active phase of orthodontic treatment. ~18 months ago, the patient underwent an unspecified apexification on tooth #8 with an MTA‐like material at another clinic, following trauma. Twelve months before presentation, she initiated orthodontic treatment with fixed appliances. Four weeks ago, she experienced the onset of spontaneous/dull pain in the right anterior maxilla. Two weeks before presentation, the pain became acute and exacerbated by chewing, which prompted her initial presentation to our clinic (T = 0). At T = 0, a comprehensive clinical/radiographic examination was performed [12]. Surgical intervention occurred at T = 1 week. Suture removal and postoperative check occurred at T = 2 weeks. Follow‐up examinations were conducted at T = 6, 12, 24, 36, and 48 months.

Clinical examination revealed no extraoral findings, including facial swelling, sinus tract, or palpable lymphadenopathy. Both teeth exhibited tenderness to percussion/palpation. Tooth #8 showed a mild coronal discoloration (Figure 1A). Periodontal probing depths were within normal limits (2–3 mm) for both teeth. Pulp sensibility testing was performed; response to cold test (Roeko, Coltène/Whaledent, Germany) and electric pulp testing (Elements Diagnostic, Kerr, USA) was negative for tooth #8 and doubtful for tooth #7. Adjacent/contralateral control teeth responded normally. Fixed orthodontic appliances were present/stable with no evidence of occlusal trauma.

FIGURE 1.

Preoperative clinical and radiographic presentation. (A) Clinical photograph showing the maxillary right central incisor (tooth #8) with mild coronal discoloration and fixed orthodontic appliances in place. (B) Preoperative panoramic radiograph (OPG) demonstrating a large periapical radiolucency in the right anterior maxilla associated with teeth #7 and #8, with evidence of previous apexification in tooth #8. (C) Preoperative periapical radiograph revealing an extensive periapical radiolucency involving both teeth and an overextended radiopaque apical plug located approximately 5 mm beyond the apex of tooth #8.

OPG/periapical radiographs (Figure 1B,C) revealed a large, ill‐defined radiolucency associated with the apices of teeth #7 and #8. An overextended radiopaque material (the previous apical plug) was noted ~5 mm beyond the apex of tooth #8. The root of tooth #8 appeared immature with thin/parallel dentinal walls and an open apex, and the canal appeared underfilled. To better characterize this complex anatomy, a limited field‐of‐view CBCT scan (NewTom VGi, Verona, Italy; FOV 8 × 8 cm, voxel size 0.125 mm, 110 kV, 1–20 mA, exposure time 5.4 s) was acquired. The CBCT revealed a large, well‐defined periapical radiolucency measuring ~15 × 15 × 12 mm that encompassed the apices of both teeth and had caused perforation of the buccal cortical plate (Figure 2A–F). For tooth #8, the immature root morphology and thin dentinal walls were confirmed, and the previously placed apical plug was visualized as extruded into the lesion, separate from the root apex, with the apical 3–4 mm of the root canal appearing void of filling material. For tooth #7, the tooth was mature and exhibited a flattened/irregular appearance suggestive of external apical root resorption, while the root canal system appeared radiographically intact.

FIGURE 2.

Preoperative cone‐beam computed tomography findings. (A) Sequential coronal CBCT slices demonstrating the full extent of the periapical lesion (measuring approximately 15 × 15 × 12 mm) encompassing the apices of both teeth #7 and #8, with perforation of the buccal cortical plate. (B) Coronal CBCT slice of tooth #8 confirming immature root morphology with thin, parallel dentinal walls and an open apex; the previously placed apical plug is visualized as an extruded fragment separate from the root apex (arrowhead), with the apical 3–4 mm of the canal appearing void of filling material. (C,D) Sagittal CBCT slices of tooth #7 and #8 showing a fully formed mature root with a flattened, irregular apical contour indicative of external apical root resorption (arrowhead); the root canal system appears radiographically intact with no prior endodontic intervention. (E,F) Axial CBCT slice demonstrating the circumferential involvement of the lesion around the apices of both teeth and the extent of buccal cortical plate destruction.

Based on the clinical/radiographic/CBCT findings (Figure 2A–F), tooth #8 was diagnosed as previously endodontically treated with symptomatic apical periodontitis. For tooth #7, clinical tenderness and its association with the extensive periapical radiolucency supported a diagnosis of symptomatic apical periodontitis. However, responses to cold and electric pulp testing were equivocal, precluding a definitive pulpal diagnosis. The uncertain pulpal status may have been influenced by trauma, orthodontics, and periapical inflammation.

3. Methods (Differential Diagnosis, Investigations, and Treatment)

After diagnosis, treatment options were discussed. Conventional therapy (orthograde retreatment of #8 and RCT of #7, with surgery if persistent) was weighed against single‐stage surgery. The latter was chosen due to buccal cortical perforation enabling direct access. Retreatment of #8 risked root integrity (immature root, thin dentin, poor apical plug, extruded material); #7 had equivocal pulpal status, risking unnecessary vital pulp removal. Conservative surgery was selected to remove the lesion, seal apices, preserve structure, and reduce orthodontic treatment burden. After discussing risks/benefits and obtaining written consent (parents) and assent (patient), the family opted for surgery, performed 1 week later.

Following administration of local anesthesia, a full‐thickness mucoperiosteal flap was raised, exposing the buccal cortical plate. The buccal cortical plate had been perforated by the lesion, and the soft tissue granulomatous lesion was easily accessed and completely enucleated for histopathological analysis.

Upon exposure of the apex of tooth #8, the extruded apical plug material was visualized as a separate/loose fragment and was removed without any manipulation/resection of the root apex. Using a piezoelectric ultrasonic unit with specialized micro‐surgical retrotips (Joya Electronics, Tehran, Iran), a conservative root‐end cavity was prepared (3–4 mm) in tooth #8. Preparation was confined to the existing canal space, preserving the fragile apical dentinal walls and avoiding any root‐end resection. For tooth #7, the flat/resorbed apex was identified, and a 3‐mm deep root‐end cavity was prepared ultrasonically, again without any resection of the root tip. The prepared root‐end cavities were thoroughly dried with sterile paper points. Nano calcium‐enriched mixture (CEM) cement (BioniqueDent, Tehran, Iran) was mixed according to the manufacturer's instructions and filled/sealed both root‐end cavities.

The surgical site was gently irrigated, and the flap was repositioned/sutured with 4‐0 nylon interrupted sutures. Post‐operative instructions were provided, including a prescription for chlorhexidine digluconate 0.2% mouthwash (twice daily for 1‐week) and ibuprofen (400 mg every 8 h as needed for pain), and a soft diet was recommended for 1‐week.

4. Conclusion and Results (Outcome and Follow‐Up)

Microscopic examination of the excised tissue with Hematoxylin/Eosin staining revealed chronically inflamed granulation tissue with a dense infiltrate of lymphocytes, plasma cells, and numerous foam cells, consistent with a diagnosis of periapical granuloma. No epithelial lining was observed, ruling out a radicular cyst (Figure 3A–C).

FIGURE 3.

Histopathological findings. (A) Photomicrograph of the excised periapical tissue (Hematoxylin and Eosin stain, original magnification ×40) showing granulation tissue with dense chronic inflammatory cell infiltration. (B) Higher magnification (×100) reveals a mixed inflammatory infiltrate composed of lymphocytes, plasma cells, and numerous foamy macrophages (foam cells; arrowheads). (C) High‐power view (×200) clearly demonstrating lipid‐laden foamy macrophages (arrowheads) within the chronically inflamed connective tissue stroma. These findings are consistent with a diagnosis of periapical granuloma. No epithelial lining was observed, excluding a radicular cyst.

At the 2‐week recall, sutures were removed, and the surgical site was healing well. The patient reported complete resolution of pre‐operative pain. At the 6‐month follow‐up, the patient remained completely asymptomatic, with no tenderness to percussion/palpation and healthy soft tissues. Compared with the immediate postoperative radiograph (Figure 4A), the 6‐month periapical radiograph showed a significant reduction in the size of the periapical radiolucency and evidence of bone formation surrounding the apices of both teeth (Figure 4B). At 1‐year follow‐up, clinical findings were unchanged, and radiographic examination demonstrated continued osseous healing with re‐establishment of a distinct lamina dura and PDL around both teeth (Figure 4C). At the 2‐year follow‐up, the patient remained symptom‐free, and orthodontic treatment was completed; the radiographic healing was complete/stable (Figure 4D). The 3‐year OPG/periapical radiographs revealed complete radiographic healing, with restoration of a normal periapical architecture, a continuous lamina dura, and a uniform PDL for both teeth (Figure 4E,F). The 4‐year periapical radiograph confirmed sustained radiographic healing, with restoration and maintenance of normal periapical architecture, a continuous lamina dura, and a uniform PDL space for both teeth; the clinical photograph showed no discoloration of teeth #7 and #8, while the OPG demonstrated complete bone healing associated with both teeth #7 and #8 (Figure 5A–C). A summary of these clinical/radiographic outcomes over the 48 months is presented in Table 1.

FIGURE 4.

Postoperative and follow‐up radiographic outcomes. (A) Immediate postoperative periapical radiograph demonstrating retrograde root‐end fillings with CEM cement in both tooth #8 (central incisor) and tooth #7 (lateral incisor); note the well‐condensed, void‐free appearance of the fillings at the apical termini. (B) Six‐month follow‐up periapical radiograph showing a significant reduction in the size of the periapical radiolucency with evidence of early bone formation surrounding both apices. (C) One‐year follow‐up radiograph demonstrating continued osseous healing and initial re‐establishment of the lamina dura and periodontal ligament space around both teeth. (D) Two‐year follow‐up radiograph revealing complete radiographic healing with restoration of normal periapical architecture and a continuous lamina dura. (E,F) Three‐year follow‐up panoramic radiograph and periapical radiograph demonstrating established radiographic healing with a uniform PDL space, intact lamina dura, and normal periapical bone architecture for both the central and lateral incisors.

FIGURE 5.

Four‐year clinical and radiographic follow‐up. (A) Clinical photograph showing both treated teeth without discoloration. (B) OPG demonstrating complete bone healing associated with teeth #7 and #8. (C) Four‐year periapical radiograph confirming the previously established healing outcomes of both teeth.

TABLE 1.

Summary of clinical and radiographic outcomes over 48 months.

Time point	Symptoms (pain/tenderness)	Clinical findings (soft tissue/percussion)	Radiographic findings
Pre‐op (T = 0)	Acute pain, tenderness to percussion	Slight erythema, negative pulp tests	Large radiolucency, extruded plug, apical resorption
1 Week Post‐op	Resolved	Healing surgical site, sutures in place	N/A
6 Months	None	Healthy, no tenderness, and functional	Significant reduction in lesion size, early bone formation
12 Months	None	Healthy, no tenderness, and functional	Continued healing, lamina dura and PDL re‐forming
24 Months	None	Healthy, no tenderness, and functional	Complete radiographic healing, normal PDL and lamina dura
36 Months	None	Healthy, no tenderness, and functional	Established radiographic healing, normal PDL and lamina dura
48 Months	None	Healthy, no tenderness, and functional; no discoloration of both teeth	Sustained radiographic healing, with normal periapical architecture, continuous lamina dura, and uniform PDL

Abbreviations: N/A: Not applicable, PDL: Periodontal Ligament.

The patient/parents expressed satisfaction with the treatment outcome because the symptoms resolved rapidly and the condition was managed through a single surgical intervention without the need for multiple endodontic procedures. The patient remained comfortable during orthodontic treatment and reported no functional/esthetic concerns during the four‐year follow‐up period.

5. Discussion

This case report details a successful 4‐year outcome following a highly conservative surgical approach to manage apical periodontitis in two adjacent teeth with markedly different developmental and treatment histories. The key departures from conventional endodontic practice were performing root‐end surgery on a mature lateral incisor with no prior orthograde RCT and revising a failed apical plug in an immature central incisor via a retrograde approach, without orthograde retreatment or root‐end resection. Only a limited number of reports have described the surgical management of periapical lesions involving vital/intact teeth without RCT [13, 14, 15].

The most significant and noteworthy finding is the complete healing of the mature lateral incisor. Traditional endodontic principles are predicated on the belief that intraradicular inflammation/infection is the primary etiology of apical periodontitis, and thus, its elimination via orthograde RCT is mandatory for healing. This case offers a hypothesis‐generating observation that prompts reconsideration of that requirement in a highly selective clinical context. We hypothesize that the successful outcome in this mature tooth can be attributed to two primary factors. First, the root‐end preparation and fluid‐tight seal with CEM cement may have effectively separated intracanal irritants and prevented their egress into the periapical tissues [15], a concept supported by the presence of external apical root resorption, which may have created a communication pathway where the apical foramen served as the primary portal of exit for bacterial byproducts [16]. Second, the surgical curettage removed the bulk of the inflammatory lesion and infected granulation tissue, drastically reducing the local bacterial load and creating a favorable environment for the immune system to clear any remaining infection [17]. The long‐term stability of this outcome also depends on the host's immune response and the absence of coronal microleakage, which were favorable in this case.

It is crucial to emphasize that this is a highly selective, hypothesis‐generating observation and is not generalizable. The favorable outcome in tooth #7 should not be interpreted as evidence that orthograde RCT is unnecessary in similar cases; rather, it underscores the importance of case‐specific biological and anatomical factors that may permit such an approach under exceptional circumstances [18].

The pulpal status of tooth #7 was equivocal, based on inconsistent responses to sensibility testing, a known limitation of these diagnostic methods [19]. Such tests may not reliably distinguish between reversible inflammation, irreversible pulpitis, or early necrosis in teeth with periapical involvement [19]. Given this diagnostic uncertainty, orthograde root canal treatment was avoided to prevent possible removal of vital pulp tissue, and a surgical approach to the periapical lesion was selected in line with minimally invasive endodontic principles [19, 20]. The biological rationale was that, regardless of pulpal status, healing depends on effective isolation of the endodontic space via a fluid‐tight apical seal combined with thorough debridement of the lesion [21]. Clinical evidence supports that successful outcomes after apical surgery are strongly associated with adequate elimination of periapical irritants and a hermetic root‐end seal. The favorable 4‐year outcome aligns with this concept, although it should be interpreted cautiously due to diagnostic limitations [19, 20, 21].

In the immature central incisor, the conservative approach preserved the remaining root structure, a critical goal for the long‐term prognosis in teeth with thin dentinal walls and an open apex, where further intervention, such as root‐end resection, may compromise structural integrity and increase fracture risk [22]. Removing the loose, extruded foreign body and placing a well‐adapted retrograde CEM plug addressed the persistent irritation without the need for complex, lengthy, and potentially weakening orthograde retreatment. This approach aligns with the broader philosophy of minimally invasive endodontics, which prioritizes the conservation of healthy tooth structure whenever possible [23, 24].

The success of this intervention was heavily dependent on advanced diagnostic imaging. CBCT was indispensable, providing a precise three‐dimensional understanding of the lesion's extent [25, 26], the exact nature of the failed plug, the immature root morphology of tooth #8, and the subtle external resorption of the lateral incisor [27]. This information was critical for formulating the minimally invasive surgical plan and avoiding the need for exploratory resection [12, 27]. CBCT also allowed for accurate assessment of the buccal cortical plate perforation, which facilitated direct surgical access and complete lesion removal. Without CBCT, the surgical approach would have been less predictable, and the decision to avoid root‐end resection would have been based on incomplete information [26].

With the emergence of artificial intelligence and machine learning in dentistry, diagnostic accuracy and treatment planning are becoming increasingly data‐driven. AI‐based models have shown promise in interpreting radiographic findings and assisting clinicians in complex decision‐making scenarios [28, 29].

The use of CEM cement as a root‐end filling biomaterial was another cornerstone of success. CEM cement is a well‐characterized endodontic biomaterial with documented biocompatibility, excellent sealing ability, hydrophilicity allowing it to set in the presence of moisture, and bioinductive properties that promote cementogenesis and osteogenesis [30, 31]. These properties are ideal for promoting periapical regeneration. Independent studies have consistently validated the clinical performance of CEM cement in various endodontic applications, including apical surgery, demonstrating comparable, if not superior, outcomes to MTA regarding tissue healing and biocompatibility [32, 33, 34].

The present report aligns with emerging evidence suggesting that conservative surgical strategies may successfully manage complex periapical lesions without mandatory orthograde endodontic treatment of all involved teeth. Recent case studies reported complete healing of a large radicular cyst following selective root‐end surgery, surgical enucleation, and root‐end filling/sealing with CEM cement, while preserving the structural integrity of an adjacent intact tooth without conventional RCT [13, 14]. Together with the present case, these reports support the concept that carefully selected periapical pathoses involving vital teeth may be managed through targeted surgical intervention and bioactive root‐end sealing while maintaining structural integrity and minimizing unnecessary endodontic procedures and costs. Furthermore, literature supports targeted surgery when the primary source is identifiable and accessible, as lesions may extend from an infected tooth without compromising adjacent vitality [18]. However, evidence is limited to case reports/small series; prospective studies with microbial analysis are needed to define biological mechanisms and success criteria.

From a clinical decision‐making perspective, this novel approach underscores the importance of individualized treatment planning that prioritizes biological preservation while addressing the etiologic source of periapical disease. Traditionally, periapical lesions involving adjacent intact teeth have often led to endodontic treatment of all implicated teeth, even when vitality tests suggest otherwise [35]. However, growing evidence indicates that periapical pathology may extend from a single infected root system to involve neighboring structures without necessarily compromising the vitality of adjacent teeth [15]. In such situations, indiscriminate orthograde RCT may represent overtreatment. Instead, a targeted, selective surgical approach that removes the pathologic lesion, eliminates the apical source of infection, and establishes an effective apical seal using bioactive materials may achieve healing while preserving the natural pulp. This biologically oriented strategy aligns with contemporary minimally invasive principles in endodontics, emphasizing preservation of healthy tissue, reduction of treatment‐related morbidity, and optimization of long‐term tooth survival [23]. Nevertheless, such approaches should be reserved for carefully selected cases supported by comprehensive clinical examination, advanced imaging when indicated, and long‐term follow‐up to confirm stable healing outcomes. The decision to adopt this strategy should be made collaboratively with the patient, with a full discussion of the uncertainties and potential risks involved.

Clinically, this case highlights that when a large periapical lesion involves adjacent teeth with different developmental statuses, a selective and biologically guided surgical strategy may sometimes provide an effective alternative to conventional multi‐step orthograde endodontic treatment. Importantly, the single‐stage surgical intervention minimized treatment duration, reduced patient burden during active orthodontic therapy, lowered overall treatment costs, and avoided the need for multiple complex endodontic procedures.

This report has several strengths, including its long‐term 4‐year follow‐up, adherence to CARE guidelines for transparent reporting [11], and the use of histopathology for definitive diagnosis [36]. The inclusion of CBCT imaging provided detailed anatomical information that enhanced treatment planning and interpretation of outcomes. However, the limitations are equally important to acknowledge. As a single case report, the findings are not generalizable. The exact microbial status of the root canal before/after surgery was not assessed, leaving the mechanism of healing to some degree of speculation. The equivocal diagnostic assessment of tooth #7 represents a fundamental limitation in interpreting the biological basis of the healing process. The long‐term outcome beyond 4 years remains unknown. The success of this approach is likely highly dependent on case‐specific factors, including root canal anatomy, lesion characteristics, and the host's immune response. Therefore, the conclusions must be framed as hypothesis‐generating, not protocol‐changing. Additionally, the lack of objective vitality testing (e.g., laser Doppler flowmetry) limits diagnostic certainty; future cases should employ such tools to better characterize pulpal status before intervention.

Selective conservative apical surgery achieved complete clinical/radiographic healing of a large periapical lesion involving adjacent immature and mature teeth after 4 years. Although not generalizable, this case offers a hypothesis‐generating observation that selective root‐end management with bioactive sealing may be effective in carefully selected cases. Future integration of advanced imaging and AI‐based predictive tools may further refine case selection and improve outcomes. Future studies are needed to validate the biological basis and clinical applicability of this approach.

Author Contributions

Saeed Asgary: conceptualization, data curation, formal analysis, investigation, methodology, validation, writing – original draft, writing – review and editing.

Funding

This case report was self‐funded.

Consent

Written informed consent was obtained from the patient to publish this case report in accordance with the journal's patient consent policy.

Conflicts of Interest

The author declares no conflicts of interest.

Data Availability Statement

The author has nothing to report.