Apical root-end filling with tricalcium silicate-based cement in a patient with diabetes mellitus: A case report

Introduction. The material used for root-end filling has to be biocompatible with adjacent periapical tissue and to stimulate its regenerative processes. Tricalcium silicate cement (TSC), as a new dental material, shows good sealing properties with dentin, high compression strengths and better marginal adaptation than commonly used root-end filling materials. Although optimal postoperative healing of periapical tissues is mainly influenced by characteristics of end-root material used, it could sometimes be affected by the influence of systemic diseases, such as diabetes mellitus (DM). Case report. We presented apical healing of the upper central incisor, retrofilled with TSC, in a diabetic patient (type 2 DM) with peripheral neuropathy. Standard root-end resection of upper central incisor was accompanied by retropreparation using ultrasonic retrotips to the depth of 3 mm and retrofilling with TSC. Post-operatively, the surgical wound healed uneventfully. How-ever, the patient reported undefined dull pain in the operated area that could possibly be attributed to undiagnosed intraoral diabetic peripheral neuropathy, what was evalu-ated clinically. Conclusion. Although TSC presents a suitable material for apical root-end filling in the treatment of chronic periradicular lesions a possible presence of systemic diseases, like type 2 DM, has to be considered in the treatment outcome estimation.


Introduction
The primary goal of periradicular surgery is to seal the apex of the root canal hermetically, preventing the passage of microorganisms or their products into adjacent periapical tissues.Traditionally, root-end filling is obtained by amalgam or different types of cement 1 .However, modern apical surgery is still seeking for the material with superb long-time mechanical properties and excellent apical obturation together with biostimulation of regenerative processes of apical tissues 2 .Beside the mentioned properties of the material used, it has to be biocompatible to the neighbouring periapical tissues 3 .On the other hand, there are still some possible complications of periradicular surgery related to disadvantages of materials used for root-end filling 4,1 .
Tricalcium silicate cement (TSC), as a new dental material, shows mechanical and safety profile which could improve the quality of apical obturation 5,6 .It was also shown that TSC possesses good sealing properties with dentin and high compression strengths 7,6 .TSC provides better marginal adaptation than commonly used root-end filling materials 8 .
Although optimal postoperative healing of periapical tissues is mainly influenced by the characteristics of root-end material used, it could sometimes be affected by the peripheral appearance of systemic diseases 4 .Diabetes mellitus (DM) results in delayed wound healing and associated complications in dental treatments 9,10 .It was already shown that DM decreased osteoblasts function in the rat model 11 .In addition, microvascular changes found in DM may decrease the reparatory processes of soft and hard tissue and, gradually, could lead to postoperative complications, such as diabetic neuropathy [12][13][14][15] .
The aim of this report was to present apical healing of the upper central incisor, retrofilled with TSC, in a diabetic patient with possible peripheral neuropathy, as a complication associated with type 2 DM.

Case report
A 53-year-old man, suffering from type 2 DM, with peripheral neuropathy and cardiovascular complications (ASA III), was referred by his general dental practitioner to the Clinic of Oral Surgery, Faculty of Dental Medicine, University of Belgrade, for root apical surgery of the right central incisor.Clinical examination showed the presence of a fistula in the region of the root apex of the tooth.There were no signs and symptoms of acute dental infection, although the patient indicated unpleasant discomfort and unmarked chronic pain of the alveolar ridge on the right side.In addition, retroalveolar radiogram was done and short canal filling with well demarcated slight periapical radiolucency were seen around the root apex of tooth (Figure 1).It was decided to perform root-end surgery, implying resection of the root-end and retrofilling with tricalcium silicate cement (TSC) (Biodentine ® , Septodont, Saint des Fausses, France) under high magnifying glass.
Standard root resection included sectioning the root-end with fissure bar for approximately 2 mm; retro-preparation was done using ultrasonic retro-tips, to the depth of 3 mm (Figure 2).TSC was placed in the 3 mm deep retrograde cavity of the root-end (Figure 3).After the setting time was finished, the wound was debrided and closed primarily.
One month after the operation, the patient complained to constant, undefined, dull pain and discomfort in the operated region, which lasted for the next 3 months.Clinical examination and control retroalveolar radiogram did not show any signs of pathological lesion (Figure 4).There was no fistula in the region of oral mucosa or attached gingiva.Also, there were no periodontal pockets around the tooth 11.Regarding that, it was necessary to distinguish the possible presence of vertical root fracture, which usually cannot be diagnosed radiographically.For that reason the re-entry was done.When a full-thickness trapezoid mucoperiostal flap was elevated, almost complete bone healing in the operated area was present (Figure 5).There were no signs of vertical root fracture.At the end, the operated area was copiously irrigated with saline and interrupted sutures were placed.Follow-up was done 3 and 6 months and 2 years after re-entry and there were no changes both clinically and radiographicaly.During these observation periods the mentioned disturbances at the operated region were recorded occasionally, with different intensity and usually lasted for several weeks.

Discussion
Different materials have been used for filling root-ends.
In vitro and in vivo studies have shown that mineral trioxide aggregate (MTA), as a gold standard, has considerable sealing ability and better marginal adaptation to dentin [16][17][18] , compared to amalgam, super-EBA (ethoxy-benzoic acid) and IRM (intermediate restorative material) cement 19 .However, many drawbacks of MTA, such as difficulties with handling, long setting time and high cost, restricts its use as a root-end filling material.In addition, it was found that in higher concentrations, MTA was toxic to cementoblasts 20 .Tricalcium silicate-based cement -Biodentine ® , was introduced as a bioactive material, with the idea of overcoming disadvantages of MTA.Its bioactivity was shown on pulp cells by stimulation biomineralisation 21 .Likewise, new calcium silicate-based cement induced odontoblast stimulation and the production of tertiary dentin in the rat pulp injury model 22 .Applied directly onto human pulp, TSC induced stimulation, biomineralization and odontoblast differentiation 23,21 .It was also shown that TSC induced osteoblast differentiation in mesenchimal stem cells 24 .When used as rootend filling material, TSC showed the least microleakage compared to other cements 25 .TSC-based cement produced more prominent Ca 2+ and Si 2+ uptake into the root canal dentine than MTA when used as a root canal obturation material in bovine incisors 2 .Butt et al. 26 suggested that Biodentine possesses better sealing ability, higher compressive strength and better handling consistency than MTA.The most recent study of Bhavana et al. 27 revealed that TSC had higher antibacterial and antifungal activity than MTA.
Having in mind all the mentioned advantages and direct biological effect of TSC on bone healing, it was expected to have a successful surgical result after being used for retrofilling in the presented patient, showing clinical and radiographic evidence of complete healing.However, the patient reported undefined dull pain in the operated area a month after surgery, which lasted for next 3 months.Pain in the operated area could possibly be attributed to undiagnosed intraoral diabetic peripheral neuropathy, concerning the fact that the patient suffered from type 2 DM for more than 10 years.It was also documented that signs of intraoral peripheral neuropathy, such as the loss of intraoral sensation, hyperesthesia, dysesthesia and temporomandibular dysfunction could be related with clinically evident peripheral diabetic neuropathy 28 .The possible detrimental influence of diabetic neuropathy in progression of chronic orofacial pain could be also corroborated with unpleasant burning mouth syndrome and nonspecific soreness that affect intraoral structures 29 .Furthermore, it was proposed that prolonged effect of local anaesthetic solution could provoke pain in the operating area.Namely, it was already shown that the incidence of diabetic neuropathy increased after spinal and neuraxial block anesthesia 30,31 .Dull pain that the patient described could possibly be explained by microangiopathy of peripheral dental nerves associated with DM and adjunct prolong ischemic effect of vasoconstrictors from local anaesthetic that was administered in the close proximity to peripheral nerves.Atypical facial pain (AFP) could be considered in differential diagnosis, having in mind its chronic character.Idiopatic or AFP could be described as deep or superficial, poorly localised, and sometimes bilateral pain, predominantly in middle-aged and older women 32, ,33 .On the other hand, dull character of pain localised only in the operated area, could possibly be attributed to peripheral diabetic neuropathy, distinguishing it clinically from AFP.

Conclusion
Tricalcium silicate cement presents a suitable material for apical root-end filling with good mechanical and biologi-cal properties.However, there are still little data concerning long-term results of using TSC as a root-end filling material in clinical trials, especially in the risk group of patients such as patients with diabetes mellitus, with changed peripheral healing capacity.Further long-term clinical studies are needed to precisely determine clinical and biological behaviour of TSC as a root-end filling material and to confirm the direct evidence of regeneration of periapical tissues in humans.