Non-surgical management of a large periapical lesion with internal resorption using PRF, hydroxyapatite and MTA

Abstract

Periapical lesions of endodontic origin are caused by microbial infection of pulp. According to various studies, it is known that necrosis of pulp provides a favourable habitat for microbes to replicate and release various toxins into the periapical tissue leading to inflammation and formation of a periapical lesion. A variety of non-invasive methods to manage such lesions include conservative root canal treatment, aspiration-irrigation technique, decompression technique, calcium hydroxide therapy, lesion sterilisation and tissue repair therapy, and the apexum procedure. We present a case report describing non-surgical management of a large periapical lesion associated with a permanent central incisor displaying internal inflammatory resorption using platelet rich fibrin (PRF), bone graft and mineral trioxide aggregate (MTA).

Background

Periapical lesions (>90%) can be classified mostly as dental granuloma, radicular cyst or abscess.^{1 2} They are caused by an active interaction between the host’s immune response and microorganisms at the interface of the periodontal membrane and the infected pulpal tissue. They are not self-healing in spite of their defensive nature.³ Therapeutic approaches to manage periapical lesions can be non-surgical endodontic treatment, endodontic surgery, with or without regenerative materials, or tooth extraction in severe cases. Eliminating or reducing microbes in the pulp system using active biomechanical preparation may lead to a successful treatment.⁴ If the lesion has direct communication with the root canal, it can be managed by drainaging pus through the access cavity. On the other hand, in cases where the lesion is separated from the apical foramen and covered by an intact epithelium, non-surgical therapies are unsuccessful.⁵ In the present case, lesion was of endodontic origin so a conservative orthograde endodontic treatment was planned that was combined with an augmentation method like calcium hydroxide treatment and lesion sterilisation and tissue repair therapy.

Conventionally, multiple and prolonged therapy with calcium hydroxide intracanal medicament has been used to treat severe periapical lesions and internal inflammatory root resorption.^{6 7} However, usage of a triple antibiotic paste has been recommended for large infected periapical lesions, as calcium hydroxide therapy alone may not be adequate for such lesions.⁸

The stem cells found in the apical papilla play an important role in regenerative procedures. However, the chances of presence of residual apical papilla cells may decrease especially in chronic periapical lesions.^{9 10} Platelet rich fibrin (PRF) being a rich source of growth factors was used along with bone graft to regenerate bone. Numerous clinical studies and case reports have reported PRF and collagen as being the best scaffolds for regenerative procedures in the necrotic teeth.¹¹ PRF not only acts as an ideal scaffold in regenerating necrotic teeth by promoting cell proliferation and differentiation but also serves as a matrix for tissue ingrowth.¹²

Rudagi and Rudagi have reported excellent outcomes with the combined use of PRF as matrix and mineral trioxide aggregate (MTA) as an apical plug in apexification.¹³ This was attributed to the autologous and biocompatible status of the PRF and MTA. In the present case, MTA was used to seal the apical part of the tooth and the canal walls to strengthen the internally resorbed walls.^14–16 Thus, where such intricacy of trauma injury exists, it seems prudent to use the advantages of the before mentioned elements in a systematic way to achieve the desired result. The following case report describes the non-surgical management of a large periapical lesion in permanent maxillary central incisor with internal resorption using a combination of PRF and hydroxyapatite bone graft as scaffold along with MTA as a matrix.

Case presentation

A young girl visited the department of paediatric and preventive dentistry with the chief complaint of a grossly decayed discoloured tooth in the upper front region for 1 year (figure 1A). The patient’s dental history revealed previous trauma when she was 10 years old and the same toothache 1 year back that subsided on medication. Medical history was not a contributing factor and further oral examination revealed that there were no affected lymph nodes and no swelling of the face. On intraoral clinical examination, a soft, fluctuant and non-tender swelling of the labial sulcus in relation to grossly decayed and discoloured maxillary left central incisor (tooth no. 21) was seen. The tooth was not tender on percussion. The tooth nos. 11 and 21 presented negative feedback on both thermal and electric pulp testing. Radiographic examination revealed a large radiolucency in tooth no. 21 periradicular area along with internal resorption of the same tooth. The preoperative radiological examination revealed a large poorly defined radiolucency, of about 4 mm × 5 mm in size, evidently involving the apices of tooth no. 21 and widening of periodontal ligament and internal inflammatory resorption in the same tooth (figure 2A). Therefore, a definitive diagnosis of pulpal necrosis and internal resorption with periapical lesion in the permanent maxillary left central incisor was made. Thus, a non-surgical orthograde endodontic treatment was planned with a single step apexification using MTA and PRF for treating tooth no. 21.

Figure 1.

(A) Preoperative clinical photograph showing coronal fracture in tooth no. 21. (B) Postoperative clinical aspect at 3 months follow-up after post and core in tooth no. 21. (C) Postoperative clinical aspect at 6 months follow-up after prosthetic rehabilitation with all ceramic crown in tooth no. 11 and 21. (D) Postoperative clinical aspect at 24 months follow-up.

Figure 2.

(A) Preoperative radiograph showing well-circumscribed radiolucency and internal resorption involving tooth no. 21. (B) Primary apical barrier with platelet rich fibrin and bone graft; Secondary apical barrier and root canal resorption defect filled with mineral trioxide aggregate. (C) The 3-month follow-up radiograph showing considerable resolution of the periapical lesion. (D) The 3-month follow-up radiograph, after post and core done in tooth no. 21. (E) After a 6-month follow-up, complete resolution of the periapical lesion and root apex repair was appreciated. (F) The 24-month follow-up radiograph.

Investigations

Preoperative intraoral periapical (IOPA) radiograph was taken at first visit. To assess the actual size, extent, nature and position of periapical lesion, a cone beam CT was done preoperatively. IOPA radiographs were taken at subsequent visits for diagnosis and later to assess healing of the periapical lesion in relation with tooth no. 21.

Differential diagnosis

Dental granuloma, periradicular cyst.

Treatment

The tooth was anaesthetised using local anaesthesia containing lignocaine with epinephrine. Following isolation with the rubber dam, access cavity preparation and removal of decayed tissue was done for tooth no. 21. There was drainage of purulent exudate from the root canal, a 23-gauge needle was inserted into the root canal attached to a 5 mL syringe and thorough irrigation using sodium hypochlorite (2.5% NaOCl) and normal saline was performed during instrumentation. After the bleeding has stopped, working length was determined followed by cleaning and shaping. Subsequently, the canal was dried with paper points and was filled with calcium hydroxide powder in combination with distilled water as a paste. During the subsequent appointment after 2 weeks, intracanal dressings were removed and irrigation was done with 5% NaOCl after that canal was dried with paper points. Triple antibiotic paste consisting of ciprofloxacin (500 mg), metronidazole (400 mg) and doxycycline (100 mg) was mixed using normal saline as vehicle and was placed in the canals by a lentulo spiral and tooth was temporised using Cavit G. After 2 weeks, the antibiotic mix was removed from the canal and a calcium hydroxide dressing was placed and confined until the canal orifice to reduce the potential tooth discolouration followed by placement of Cavit G. After 2 weeks, no evidence of exudate was noticed from the canal, and hence, the tooth was considered suitable for formation of an artificial plug. A PRF membrane along with bone graft (SYBOGRAF—synthetic hydroxyapatite and β tricalcium phosphate bone graft) was inserted in the apical 1–2 mm space of the canal which formed a primary stoppage. To PRF prepare, 10 mL of intravenous blood was drawn from the antecubital vein and was collected in a 10 mL sterile tube without anticoagulant which was centrifuged immediately at 3000 rotations per minute for 10 min. This allowed formation of the fibrin clot in the middle of the tube between the red blood cells and acellular plasma layer. This was followed by the placement of MTA mixed in the ratio of 1:3 and condensed in small increments in the canal using a hand plugger gently until a barrier thickness of 4–5 mm was established, where the MTA acted as the secondary apical barrier. An IOPA radiograph verified the adequacy of the plug at the apex (figure 2B). Later, MTA was also placed on the canal walls which had become thin due to internal resorption.

Outcome and follow-up

Intraoral presentation at 3 months follow-up after post and core in tooth no. 21 (figure 1B). Postoperative clinical aspect at 6 months follow-up after prosthetic rehabilitation with all ceramic crown in tooth no. 11 and 21 (figure 1C). Postoperative clinical aspect at 24 months follow-up (figure 1D). At 3 months follow-up, the patient was asymptomatic and partial resolution of radiolucency was observed (figure 2C), so post and core was done in tooth no. 21 (figure 2D) followed by prosthetic rehabilitation using all ceramic crown. At 6 months follow-up, a complete resolution of radiolucency was appreciated (figure 2E). The patient was followed up after 24 months and there was no abnormal finding (figure 2F).

Discussion

The clinical case presented here appeared to have a trauma sequel leading to an internal inflammatory resorption that radiographically displayed a large periradicular radiolucency in relation to tooth no. 21. A systematic management approach was followed: calcium hydroxide therapy + triple antibiotic paste + PRF along with bone graft + MTA.

Here, large periradicular lesion associated with the root canal and its development was distinctly connected with the presence of microbes in the canal that was suggestive of its potential response to non-surgical treatment.^{17 18} Research has confirmed that proper biomechanical preparation, asepsis and obturation of the root canal leads to success of the treatment that promotes healing of the large periapical lesions.^{19 20} Studies have observed either partial or complete resolution of periapical lesions in 82.3%–87.9% of cases that were treated with non-surgical endodontics.^{21 22} Consideration to surgical treatment shall be given in cases where there is failure of endodontic treatment and in cases which cannot be treated non-surgically due to anatomical variations in the root canal system. In paediatric patients, however, surgical intervention may involve significant anxiety and agony for minor surgical procedures, such as apicoectomy. Additionally, increased bone loss can occur in surgical procedures. Therefore, treating such lesions non-surgically would make the treatment simple for the patient.

Another alternative technique is calcium hydroxide apexification, but an increased number of visits which would have caused prolonged treatment time. MTA is used as a substitute for calcium hydroxide as it reduces the treatment time. Usage of MTA leads to minimal delay before placing a definite restoration which decreases the persistent highly alkaline effect of calcium hydroxide and potential chances of coronal discharge. So, considering the condition of the tooth, MTA apexification seemed more suitable.

In the present study, root canals were filled with calcium hydroxide powder in combination with distilled water as a paste for 2 weeks. Calcium hydroxide is the most widely used intracanal dressing for the disinfection of the root canal due to its high pH and bactericidal activity. Various studies have tested the antimicrobial effects of calcium hydroxide, where in 97% of treated cases successful asepsis of the canals was observed after 1 month.²³ The evidence from literature has demonstrated effectiveness of calcium hydroxide medicament for the root canal treatment in children with large periapical lesions.^{24 25}

Literature has shown that triple antibiotic paste is helpful in removing microbes from deep layers of infected dental tissue. Metronidazole is preferred over other bactericidal drugs as it has a wide range of effects against anaerobes. Reports have shown that it can disinfect the deep layers of carious lesions and diffuse throughout the dentine.²⁶ At the same time, ciprofloxacin and doxycycline exhibit their action on bacteria resistant to metronidazole, most commonly Propionibacterium acnes and Prevotella intermedia.^27–29 The triple antibiotic paste has been proven to be effective in endodontic regenerative therapy³⁰ and for the treatment of large periapical lesions.³¹ In the present case, triple antibiotic paste was considered due to the purulent nature of the discharge from the canal.

To re-establish periodontal attachment and to promote bone regeneration, PRF membrane was used along with bone graft material. This is mostly based on the concept of guided tissue regeneration, which facilitates the development of space that allows cellular events needed to stimulate periodontal reattachment and mineralisation through collective osteoinductive properties of both the materials.³² Hydroxyapatite healing is simply the encapsulation of graft connective tissue and not true regeneration. PRF contains assembly of growth factors such as insulin-like growth factor, platelet-derived growth factor, transforming growth factor β1 etc, that exhibit various potential local properties such as cell migration, cell attachment, cell proliferation and cell differentiation.³³ Therefore, PRF and bone graft were used in combination.

MTA is similar to calcium hydroxide as it is highly alkaline in nature and provides antibacterial properties. A biological seal is formed by migration and differentiation of hard tissue forming cells onto the MTA surface. The calcium hydroxide produced from precipitated calcium confers the alkaline properties to MTA after hydration. In the early 1990s, MTA was used for lateral root perforation repair. This material has an edge over calcium hydroxide owing to its bacterial effects, mechanical properties, radiopaque nature and the potential to set in the presence of tissue fluids.^{34 35} Therefore, MTA has been established as a choice of material for apexification of non-vital teeth. To strengthen the tooth and enhance the prognosis the bioactive material MTA was also placed in the internal resorption defects considering the thin and weakened tooth structure.^{36 37} The expansion of MTA on setting improves the sealing capacity of this material making it appropriate for repair of root perforations to establish the periodontal reattachment.

Patient’s perspective.

Me and my daughter are thrilled with results of this treatment procedure. I never expected that it will turn out to be this way without my daughter undergoing any surgical procedure.

Learning points.

• The strategy of using platelet rich fibrin with bone graft and mineral trioxide aggregate through non-surgical method proved to be highly effective in treating teeth with internal resorption and large periapical lesions to restore normal function and health.

• The systematic approach of using calcium hydroxide to inhibit the resorption induced by the osteoclastic cells and use of triple antibiotic paste for disinfection of deep dentin layers facilitated the complete microbial elimination from the root canal space and periapical area.

• Considerably rapid healing of the periapical lesion and almost complete resolution of radiolucency at 3 months was appreciated.

Ethics statements

Patient consent for publication

Consent obtained from parent(s)/guardian(s).