Basic Research| Volume 49, ISSUE 4, P402-409, April 2023

Irritation of Dental Sensory Nerves Promotes the Occurrence of Pulp Calcification

Published:February 07, 2023DOI:



      Pulp calcification (PC) often appears in strong association with nerve fiber bundles, which indicates the important role of dental nerves in the formation of PC. Additionally, given that sensory nerves and calcitonin gene-related peptide (CGRP) secreted from sensory nerve fibers are involved in physiological and pathological bone formation, we aimed to determine whether chronic irritation of sensory nerves can promote the occurrence of PC.


      A sensory nerve irritation rat model was established via ligation of the inferior alveolar nerve (IAN), and face grooming behavior was analyzed as a measure of pain sensation. Two months post-surgery, PC was determined by imaging and histologic analyses.


      Rats in the IAN-chronic constriction injury (IAN-CCI) group showed spontaneous pain-associated behavior after the operations and pain tolerance on the 60th postoperative day. The imaging and histological analysis showed more calcified particles in the IAN-innervated first and second molars after day 60 of the dental sensory nerve irritation. These calcified masses had a dentin-like structure that contained sparse, irregularly oriented tubules. Compared to the control and sham groups, the odontoblasts located in the periphery of radicular pulp aligned along a thicker layer of predentin; which expressed more nestin with longer and stouter processes in the IAN-CCI group. Additionally, more CGRP-positive nerves were observed in the IAN-CCI group.


      Irritation of sensory nerves promotes PC formation, and the increased density of CGRP-immunolabeled fibers probably contributes to this process. This highlights the significance of dental sensory nerves in the formation of PC.

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        • Goga R.
        • Chandler N.P.
        • Oginni A.O.
        Pulp stones: a review.
        Int Endod J. 2008; 41: 457-468
        • Inagaki Y.
        • Yoshida K.
        • Ohba H.
        • et al.
        High glucose levels increase osteopontin production and pathologic calcification in rat dental pulp tissues.
        J Endod. 2010; 36: 1014-1020
        • Milcent C.P.F.
        • da Silva T.G.
        • Baika L.M.
        • et al.
        Morphologic, structural, and chemical properties of pulp stones in extracted human teeth.
        J Endod. 2019; 45: 1504-1512
        • Symons A.L.
        • Symons D.J.
        Pulpal obliteration related to long-term glucocorticosteroid medication.
        Spec Care Dentist. 1994; 14: 103-107
        • Pettiette M.T.
        • Zhong S.
        • Moretti A.J.
        • et al.
        Potential correlation between statins and pulp chamber calcification.
        J Endod. 2013; 39: 1119-1123
        • Srivastava K.C.
        • Shrivastava D.
        • Nagarajappa A.K.
        • et al.
        Assessing the prevalence and association of pulp stones with cardiovascular diseases and diabetes mellitus in the Saudi Arabian population-a CBCT based study.
        Int J Environ Res Public Health. 2020; 17: 9293
        • Hayano S.
        • Fukui Y.
        • Kawanabe N.
        • et al.
        Role of the inferior alveolar nerve in rodent lower incisor stem cells.
        J Dent Res. 2018; 97: 954-961
        • Liu A.Q.
        • Zhang L.S.
        • Fei D.D.
        • et al.
        Sensory nerve-deficient microenvironment impairs tooth homeostasis by inducing apoptosis of dental pulp stem cells.
        Cell Prolif. 2020; 53: e12803
        • Krage T.L.
        • Stiefel A.
        • Stephan B.M.
        • et al.
        Microhardness changes in dentine after neonatal capsaicin application.
        Int Endod J. 2005; 38: 570-574
        • Sorkin M.
        • Huber A.K.
        • Hwang C.
        • et al.
        Regulation of heterotopic ossification by monocytes in a mouse model of aberrant wound healing.
        Nat Commun. 2020; 11: 722
        • Ricucci D.
        • Loghin S.
        • Niu L.N.
        • et al.
        Changes in the radicular pulp-dentine complex in healthy intact teeth and in response to deep caries or restorations: a histological and histobacteriological study.
        J Dent. 2018; 73: 76-90
        • Korkmaz Y.
        • Imhof T.
        • Kämmerer P.W.
        • et al.
        The colocalizations of pulp neural stem cells markers with dentin matrix protein-1, dentin sialoprotein and dentin phosphoprotein in human denticle (pulp stone) lining cells.
        Ann Anat. 2021; 239: 151815
        • Vos B.P.
        • Strassman A.M.
        • Maciewicz R.J.
        Behavioral evidence of trigeminal neuropathic pain following chronic constriction injury to the rat's infraorbital nerve.
        J Neurosci. 1994; 14: 2708-2723
        • Deseure K.
        • Hans G.H.
        Chronic constriction injury of the rat’s infraorbital nerve (IoN-CCI) to study trigeminal neuropathic pain.
        J Vis Exp. 2015; 21: 53167
        • Rabiolo A.
        • Bignami F.
        • Rama P.
        • et al.
        VesselJ: a new tool for semiautomatic measurement of corneal neovascularization.
        Invest Ophthalmol Vis Sci. 2015; 56: 8199-8206
        • Ye Z.
        • Wei J.
        • Zhan C.
        • et al.
        Role of transforming growth factor beta in peripheral nerve regeneration: cellular and molecular mechanisms.
        Front Neurosci. 2022; 16: 917587
        • Naftel J.P.
        • Richards L.P.
        • Pan M.
        • et al.
        Course and composition of the nerves that supply the mandibular teeth of the rat.
        Anat Rec. 1999; 256: 433-447
        • Xu J.
        • Wang J.
        • Chen X.
        • et al.
        The effects of calcitonin gene-related peptide on bone homeostasis and regeneration.
        Curr Osteoporos Rep. 2020; 18: 621-632
        • Kim T.H.
        • Park S.K.
        • Choi S.Y.
        • et al.
        Morphologic change of parvalbumin-positive myelinated axons in the human dental pulp.
        J Endod. 2017; 43: 977-981
        • Paik S.K.
        • Lee D.S.
        • Kim J.Y.
        • et al.
        Quantitative ultrastructural analysis of the neurofilament 200-positive axons in the rat dental pulp.
        J Endod. 2010; 36: 1638-1642
        • Byers M.R.
        Chewing causes rapid changes in immunoreactive nerve patterns in rat molar teeth: implications for dental proprioception and pain.
        Arch Oral Biol. 2019; 107: 104511
        • Seino H.
        • Seo K.
        • Maeda T.
        • et al.
        Behavioural and histological observations of sensory impairment caused by tight ligation of the trigeminal nerve in mice.
        J Neurosci Methods. 2009; 181: 67-72
        • Ding W.
        • You Z.
        • Shen S.
        • et al.
        An improved rodent model of trigeminal neuropathic pain by unilateral chronic constriction injury of distal infraorbital nerve.
        J Pain. 2017; 18: 899-907
        • Yu X.
        • Gong Z.
        • Lin Q.
        • et al.
        Denervation effectively aggravates rat experimental periodontitis.
        J Periodontal Res. 2017; 52: 1011-1020
        • Zhan C.
        • Huang M.
        • Yang X.
        • et al.
        Dental nerves: a neglected mediator of pulpitis.
        Int Endod J. 2021; 54: 85-99
        • Byers M.R.
        • Taylor P.E.
        Effect of sensory denervation on the response of rat molar pulp to exposure injury.
        J Dent Res. 1993; 72: 613-618
        • Taylor P.E.
        • Byers M.R.
        An immunocytochemical study of the morphological reaction of nerves containing calcitonin gene-related peptide to microabscess formation and healing in rat molars.
        Arch Oral Biol. 1990; 35: 629-638
        • Bernick S.
        Effect of aging on the nerve supply to human teeth.
        J Dent Res. 1967; 46: 694-699
        • Lazzaretti D.N.
        • Bortoluzzi G.S.
        • Torres Fernandes L.F.
        • et al.
        Histologic evaluation of human pulp tissue after orthodontic intrusion.
        J Endod. 2014; 40: 1537-1540
        • Chen Y.
        • Shen W.
        • Tang C.
        • et al.
        Targeted pathological collagen delivery of sustained-release rapamycin to prevent heterotopic ossification.
        Sci Adv. 2020; 6: eaay9526
        • Sang X.
        • Wang Z.
        • Shi P.
        • et al.
        CGRP accelerates the pathogenesis of neurological heterotopic ossification following spinal cord injury.
        Artif Cells Nanomed Biotechnol. 2019; 47: 2569-2574
        • Caviedes-Bucheli J.
        • Lopez-Moncayo L.F.
        • Muñoz-Alvear H.D.
        • et al.
        Expression of substance P, calcitonin gene-related peptide and vascular endothelial growth factor in human dental pulp under different clinical stimuli.
        BMC Oral Health. 2021; 21: 152
        • Caviedes-Bucheli J.
        • Lombana N.
        • Azuero-Holguín M.M.
        • et al.
        Quantification of neuropeptides (calcitonin gene-related peptide, substance P, neurokinin A, neuropeptide Y and vasoactive intestinal polypeptide) expressed in healthy and inflamed human dental pulp.
        Int Endod J. 2006; 39: 394-400
        • Zhang M.
        • Fukuyama H.
        CGRP immunohistochemistry in wound healing and dentin bridge formation following rat molar pulpotomy.
        Histochem Cell Biol. 1999; 112: 325-333
        • Kline L.W.
        • Yu D.C.
        Effects of calcitonin, calcitonin gene-related peptide, human recombinant bone morphogenetic protein-2, and parathyroid hormone-related protein on endodontically treated ferret canines.
        J Endod. 2009; 35: 866-869