Successful Healing of Periapical Pathology with Partial Pulpotomy in a Mature Permanent Molar: A Case Report

Introduction

Preserving tooth vitality is an aim that helps maintain the functions of vital dental pulp tissue. These benefits include nutritive, inductive, formative, protective, sensitive, and defensive or reparative functions. Presence of bacteria in carious dental tissue can reach the dental pulp, itself or its by-products or toxins that are released from the demineralized tissues, causing an intense inflammation that adversely affects normal pulp functions [1]. Arresting caries progression can change this situation, as it stimulates the progenitor stem cells to differentiate to odontoblast-like cells [2]. Tertiary reparative dentin will then be secreted by the odontoblast-like cells, resulting in dentin bridge formation [2].

Vital pulp therapy approaches include indirect pulp treatment, direct pulp capping, partial (Cvek) pulpotomy, and full pulpotomy [3], and such treatments can be performed in teeth diagnosed as reversible pulpitis with normal apical area. Until recently, histological studies showed that correlation between clinical diagnosis and histologic diagnosis of teeth diagnosed as irreversible pulpitis is only 84.4% and the remaining 15.6% are still in the reversible pulpitis stage histologically [4]. Thus, vital pulp therapy approaches were introduced to be performed in teeth indicative of irreversible pulpitis [5–7].

The success of vital pulp therapy is dependent on the ability of dental pulp tissue to repair, in addition to the biocompatibility of the capping material used [8]. Mineral trioxide aggregate (MTA) was the standard material used in vital pulp therapy procedures as it was shown to induce compact dentin bridge that is free from inflammation [9]. However, it has the disadvantages of poor handling properties, long setting time, and potential for tooth discoloration [10]. As a result, new calcium silicate-based materials were introduced to address these disadvantages [11], such as Biodentine.

Biodentine has dentin-like mechanical properties; therefore, it is appropriate as a dentin substitution material due to its good compressive strength. It has a shorter setting time than to MTA. In addition, wet conditions will not interfere with its setting [12]. It was shown that it is suitable for dentin-pulp complex regeneration as it induces the formation of well-arranged layer of odontoblast and odontoblast-like cells that produce thick tubular dentin bridge, with no inflammation [13].

According to the American Association of Endodontists, if a tooth has a diagnosis of irreversible pulpitis associated with periapical symptoms or periapical pathology, non-surgical root canal treatment is the treatment of choice [14]. Therefore, performing vital pulp therapy approaches in teeth associated with periapical pathology remains controversial.

This case report presents a vital pulp therapy procedure in a mature mandibular right first permanent molar tooth diagnosed as irreversible pulpitis with periapical pathology that exhibited complete healing at follow-up.

Case Report

A 10-year-old female was referred to the endodontic clinics for management of mature mandibular right first permanent molar tooth (tooth #46). She presented with her mother and expressed a chief complaint of previous pain with cold drinks and chewing candy, but had no current pain. Her medical history was insignificant and she was medically fit (ASA type I). Clinical examination revealed cavitated tooth #46 as a result of dental caries and exhibited a lingering sensation upon cold testing using Endo ice refrigerant spray (Coltene, Cuyahoga Falls, OH, USA) but normal sensation to percussion and palpation tests. An intraoral periapical radiograph was taken and showed a deep caries lesion approaching the dental pulp with broken lamina dura apically, in addition to presence of peri-apical radiolucency around mesial and distal roots. Her peri-apical index (PAI) score was 4 [15] (Figure 1).

After clinical examination and proper endodontic testing, the tooth was diagnosed as asymptomatic irreversible pulpitis with asymptomatic apical periodontitis. The decision was made to perform non-surgical root canal treatment, and the patient’s mother provided treatment consent.

The tooth was anaesthetized with inferior alveolar nerve block by administration of 2% lidocaine hydrochloride with 1: 100 000 epinephrine (Septodont, Saint-Maur-des-Fosses, France). Single tooth dental dam isolation was achieved afterwards. Caries excavation was completed using an Endo access bur with water coolant. Dental pulp exposure occurred, revealing vital pulp tissue with controlled bleeding (Figure 2).

Minutes thereafter, the patient started suddenly struggling and crying and was not cooperative enough to complete non-surgical root canal treatment, so we decided to perform a full pulpotomy instead. The coronal portion of the dental pulp tissue was removed to reach the level of canals orifices; however, it was not reached, as the patient was extremely uncooperative. The patient’s mother was informed that proper treatment was difficult to accomplish due to uncooperativeness of the patient, and partial pulpotomy will be completed; however, non-surgical root canal treatment was encouraged, which can be performed under general anesthesia. The patient’s mother agreed to continue forward; therefore, the cavity was irrigated with 2.5% sodium hypochlorite (NaOCl), then Biodentine (Septodont, Saint-Maur-des-Fosses, France) was placed, covering the dental pulp tissue. After that, the patient started to settle down, so the decision was made to restore the tooth with resin composite permanent restoration instead of placing a temporary restoration, as her 2 previous appointments had been missed, suggesting the potential to miss further appointments (Figure 3).

Multiple attempts were made to contact the patient’s parents to schedule a non-surgical root canal treatment under general anesthesia, but no response was received. After 6 months, the patient’s mother replied, stating that the patient had been free of pain and symptoms after treatment was provided. A follow-up appointment was scheduled, and clinical examination revealed an intact composite restoration with no signs of leakage or discoloration. The tooth responded to electric pulp testing (EPT), and exhibited normal response to cold, percussion, and palpation tests. Intraoral periapical radiograph revealed normal bone features with complete periapical pathology healing and development of intact lamina dura around both mesial and distal roots (Figure 4).

Recently, the patient’s mother was contacted to schedule an appointment to obtain an intraoral postoperative picture of resin composite permanent restoration. However, even when an incentive was offered, she did not support the need to attend, as her daughter was without pain and symptoms, and they live far away.

Discussion

Non-surgical root canal treatment is indicated for teeth diagnosed as irreversible pulpitis, as dental pulp tissue is inflamed and incapable of healing [14]. However, it involves full removal of dental pulp tissue, thus losing vital pulp benefits. Root canal treated teeth demonstrated lower survival rates and greater susceptibility for root fracture compared to vital teeth [16], as the proprioceptive sensation property of vital dental pulp tissue protects from heavy occlusal loading [17]. Thus, more conservative treatment options such as vital pulp therapy approaches are encouraged to preserve the vitality of the dental pulp tissue to maintain its functions.

Studies have revealed effective and successful outcome of full pulpotomy in teeth diagnosed as irreversible pulpitis with normal apical area [7,18]. A systematic review showed an average of 97.4% clinical success rate and 95.4% radiographic success rate after 1 year [7]. Another study revealed an 88% success rate after 1 year [18]. However, few studies demonstrated healing of teeth diagnosed as irreversible pulpitis with periapical pathology involvement following full pulpotomy procedures [1,5]. Taha et al revealed an overall success rate of 92.3% after 1 year in patients ages 10–70 years [5]. A case report of Biodentine full pulpotomy performed in mature permanent 2 teeth in 40- and 25-year-old patients revealed complete healing of periapical pathology of PAI 2; however, the teeth had no response to cold or electric pulp testing (EPT) [1]. This present case report shows a successful outcome of partial pulpotomy in a mature mandibular right first permanent molar tooth diagnosed as irreversible pulpitis with periapical pathology involvement.

In this case, tooth #46 was associated with lingering sensation upon cold testing, which is a clinical sign of irreversible pulpitis [14]. Furthermore, intraoral periapical radiograph revealed a deep caries lesion associated with periapical radiolucency, indicating inflammation and destruction of apical tissues [14]. It was diagnosed as asymptomatic irreversible pulpitis with asymptomatic apical periodontitis. Previous studies that demonstrated healing of periapical pathology involvement had PAI ≤2 [1,5]. However, tooth #46 had larger periapical pathology, with a PAI score of 4, classified as apical periodontitis with a well-defined radiolucent area [15].

The presence of periapical radiolucency in a tooth with irreversible pulpitis can be explained by the ability of bacterial byproducts and toxins to move faster than the bacteria itself in reaching the periapical area, consequently leading to release of inflammatory cytokines that cause bone destruction and apical periodontitis [19,20].

This patient presented with no pain, which might have contributed to the success of the treatment as it was shown that presence of preoperative pain is a negative prognostic factor in pulpotomy procedures [21]. An important aspect in success of vital pulp therapy is accurate endodontic diagnosis. However, objective clinical tests have shown a provisional endodontic diagnosis that may not be reliable, as its not based on histo-logical confirmation [22]. Therefore, it was suggested that vital pulp therapy could be performed in teeth diagnosed as irreversible pulpitis, if the exposed dental pulp tissue revealed a controlled bleeding status, since it is an appropriate indicator of the extent of inflammation [22]. In this case, a decision was made to perform partial pulpotomy due to patient uncooperativeness and as hemostasis was achieved.

A 2.5% concentration of sodium hypochlorite (NaOCl) was used as an irrigant instead of a higher concentration, as an inverse relationship was reported between NaOCl concentration and stem cell differentiation and survivability [23]. In addition, it was shown that the higher the NaOCl concentration, the lower the dentin sialophosphoprotein expression, which has a role in tooth development and dentinogenesis [23]. Another study showed that lower concentrations of NaOCl did not have a negative effect on human dental pulp cell viability when used in revascularization of immature teeth [24].

Biodentine was used as the pulp capping material. It has good tissue regeneration ability as it provides an ultimate environment for repair by inducing the differentiation of mesenchymal stem cells to odontoblast-like cells, which produce a dentin bridge barrier [25]. It was noticed in the immediate postoperative intraoral periapical radiograph that the Biodentine was not packed properly; however, healing occurred. This can be attributed to its good sealing properties by the formation of hydroxyapatite crystals that improve marginal integrity, preventing micro-leakage, in addition to its superior bonding properties to resin composite restoration after 72 h [26], which prevented contamination, thus facilitating healing.

Several randomized clinical trials revealed no significant difference in outcome between full pulpotomy and partial pulp-otomy in teeth diagnosed as irreversible pulpitis [27,28]. Furthermore, it was shown that pulpotomy and non-surgical root canal treatment in teeth diagnosed as irreversible pulpitis had comparable success rates [29,30]. However, pulpotomy was reported to be associated with higher patient satisfaction, including cost of treatment, time required for treatment, pain during treatment, and pleasantness [29]. Thus, pulpotomy can be considered an effective treatment alternative to non-surgical root canal treatment in teeth diagnosed as irreversible pulpitis.

Treatment outcome assessment should be based on clinical and radiographic evaluation, which can be regarded as success when there are no symptoms present and there is healing of periapical involvement and preservation of dental pulp vitality [31]. Teeth treated with full pulpotomy are usually not responsive to dental pulp testing [1]. It was shown that after MTA-full pulpotomy, 94.7% of teeth were responsive to electric pulp testing and only 13.5% were responsive to cold testing after 1 year [32]. However, teeth treated with either direct pulp capping or partial pulpotomy were responsive [1].

In this case, after 6 months, the patient had no symptoms. In addition, the periapical radiolucency around the mesial and distal roots was healed, with development of an intact lamina dura. Upon dental pulp testing, the tooth was responsive to electric pulp testing and had normal response to cold, percussion, and palpation tests.

Aging is thought to affect dental pulp vascularity and cellularity, thus affecting pulp healing and regenerative ability after vital pulp therapy. With older age, a fibrous matrix is produced by the existing fibroblasts [33], which results in deposition of collagen fibers in blood vessels walls [34]. In addition, due to secondary dentin formation, calcifications can accumulate in vessels, leading to reduction in blood circulation and thus lower vascularity [35]. This finding was supported in a further publication reporting that the mean vessel area and mean vessel diameter in dental pulp decreased with aging [33].

A 50% lower cellular content was seen in dental pulp of older people [36], thus reducing pulp cellular functions [37]. The aged human dental pulp stem cells (DPSCs) exhibited reduced ability to differentiate and proliferate [38], which can be attributed to alteration in expression of bone-related genes [39]. Compared to different types of human stem cells, human DPSCs have the highest level of senescence resistance in an inflammatory environment [40], and providing an appropriate environment can reverse the age-related changes in DPSCs [39]. Human DPSCs collected from molar teeth of donors ages 16 to 66 years exhibited comparable regenerative properties when cultured in nanostructured hydroxyapatite scaffolds [41].

Vital pulp therapy approaches were documented in permanent teeth with different age groups ranging from 6 to 70 years [5–8]. Age appears not to influence the outcome of pulpotomy in permanent teeth based on the available evidence [21,42,43]. Hemostasis and ability to control pulpal bleeding was the most important factor in determining the success rate [42].

When comparing the dental pulp of primary and permanent teeth, it was shown that both feature similar nerve supply and vascular architecture [44]. However, the primary teeth have a reduced regenerative ability due to their thinner odontoblastic layer, which is considered the main difference in pulp morphology [44]. A histological study showed that dental pulp of primary teeth is more vascular than in permanent teeth, but this difference was significant only in the mid-coronal area [45].

Conclusions

This case report shows that non-surgical root canal treatment may not be needed in inflamed dental pulp of a tooth diagnosed as irreversible pulpitis with periapical pathology involvement, even with large periapical radiolucency exhibiting PAI score of 4. Vital pulp therapy approaches such as partial pulp-otomy can be a successful alternative treatment that helps the dental pulp and periapical tissue to return to a healthy condition to preserve its functions. This outcome can be achieved with proper selection of materials, which provide an environment that is suitable for repair. An extended follow-up period is needed to confirm the result. Considering a similar approach in older patients would help gain a more comprehensive understanding of its potential as a treatment method.