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Lee KH, Kim UJ, Cha M, Lee BH. Inhibiting Nav1.7 channels in pulpitis: An in vivo study on neuronal hyperexcitability. Biochem Biophys Res Commun 2024; 717:150044. [PMID: 38718567 DOI: 10.1016/j.bbrc.2024.150044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 04/30/2024] [Indexed: 05/21/2024]
Abstract
Pulpitis constitutes a significant challenge in clinical management due to its impact on peripheral nerve tissue and the persistence of chronic pain. Despite its clinical importance, the correlation between neuronal activity and the expression of voltage-gated sodium channel 1.7 (Nav1.7) in the trigeminal ganglion (TG) during pulpitis is less investigated. The aim of this study was to examine the relationship between experimentally induced pulpitis and Nav1.7 expression in the TG and to investigate the potential of selective Nav1.7 modulation to attenuate TG abnormal activity associated with pulpitis. Acute pulpitis was induced at the maxillary molar (M1) using allyl isothiocyanate (AITC). The mice were divided into three groups: control, pulpitis model, and pulpitis model treated with ProTx-II, a selective Nav1.7 channel inhibitor. After three days following the surgery, we conducted a recording and comparative analysis of the neural activity of the TG utilizing in vivo optical imaging. Then immunohistochemistry and Western blot were performed to assess changes in the expression levels of extracellular signal-regulated kinase (ERK), c-Fos, collapsin response mediator protein-2 (CRMP2), and Nav1.7 channels. The optical imaging result showed significant neurological excitation in pulpitis TGs. Nav1.7 expressions exhibited upregulation, accompanied by signaling molecular changes suggestive of inflammation and neuroplasticity. In addition, inhibition of Nav1.7 led to reduced neural activity and subsequent decreases in ERK, c-Fos, and CRMP2 levels. These findings suggest the potential for targeting overexpressed Nav1.7 channels to alleviate pain associated with pulpitis, providing practical pain management strategies.
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Affiliation(s)
- Kyung Hee Lee
- Department of Dental Hygiene, Division of Health Science, Dongseo University, Busan, 47011, Republic of Korea
| | - Un Jeng Kim
- Department of Physiology, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea
| | - Myeounghoon Cha
- Department of Physiology, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea.
| | - Bae Hwan Lee
- Department of Physiology, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea.
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Shimizu K, Yasukawa T, Ohara K, Noma N, Hayashi M, Takeichi O. Mirogabalin as a Therapeutic Option for Neuropathic Pain Emerging Post-endodontic Treatment: A Two-Case Report. J Endod 2024:S0099-2399(24)00357-1. [PMID: 38901645 DOI: 10.1016/j.joen.2024.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 06/07/2024] [Accepted: 06/11/2024] [Indexed: 06/22/2024]
Abstract
INTRODUCTION Occlusal and percussion pain may manifest occasionally following endodontic treatment, influencing retreatment decisions. Two cases of periapical neuropathic pain, classified as post-traumatic trigeminal neuropathic pain according to the International Classification of Orofacial Pain, are presented. Although mirogabalin is effective in managing neuropathic pain, there is a lack of clinical reports on its use for occasional post-traumatic trigeminal neuropathic pain after endodontic treatment. These cases highlight clinical symptoms and successful treatment with mirogabalin for post-traumatic trigeminal neuropathic pain after endodontic treatment, providing clinicians a "take-away" lesson for improving patient condition. METHODS The patients, referred by their primary dentist due to postendodontic abnormal pain, found no relief with antibiotics or nonsteroidal anti-inflammatory drugs. Although no findings including swelling or periapical radiolucency were observed around the tooth, they experienced occlusal and percussion pain. Local anesthetic testing showed that the pain originated from the peripheral area around the tooth rather than from central sensitization. Dental radiography and cone-beam computed tomography revealed no abnormal findings. Root canal retreatment was performed by a specialist in endodontic treatment. Although endodontic retreatment drastically decreased visual analog scale pain score, pain persisted. Based on the International Classification of Orofacial Pain criteria, diseases other than post-traumatic trigeminal neuropathic pain were excluded. Mirogabalin (10 mg/d) was prescribed once daily before bedtime. RESULTS Visual analog scale scores gradually and drastically decreased 2 weeks after mirogabalin therapy. Several months later, no recurrence of postendodontic pain was observed after tapering off and discontinuing mirogabalin. CONCLUSIONS These findings suggest the possibility of a new treatment method for post-traumatic trigeminal neuropathic pain after endodontic treatment.
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Affiliation(s)
- Kohei Shimizu
- Department of Endodontics, Nihon University School of Dentistry, Tokyo, Japan; Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan.
| | - Takuya Yasukawa
- Department of Endodontics, Nihon University School of Dentistry, Tokyo, Japan; Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
| | - Kinuyo Ohara
- Department of Endodontics, Nihon University School of Dentistry, Tokyo, Japan; Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
| | - Noboru Noma
- Department of Oral Medicine, Nihon University School of Dentistry, Tokyo, Japan; Division of Clinical Research, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
| | - Makoto Hayashi
- Department of Endodontics, Nihon University School of Dentistry, Tokyo, Japan; Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
| | - Osamu Takeichi
- Department of Endodontics, Nihon University School of Dentistry, Tokyo, Japan; Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
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Kim HJ, Oh S, Kwon J, Choi KK, Jang JH, Kim DS. Desensitizing efficacy of a universal dentin adhesive containing mesoporous bioactive glass on dentin hypersensitivity: a randomized clinical trial with a split-mouth model. Sci Rep 2024; 14:13926. [PMID: 38886498 PMCID: PMC11183245 DOI: 10.1038/s41598-024-64404-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 06/07/2024] [Indexed: 06/20/2024] Open
Abstract
This split-mouth blinded randomized controlled study compared the efficacy of a desensitizing agent with oxalate/resin polymer and a universal adhesive containing mesoporous bioactive glass (MBG) for dentin hypersensitivity (DH) relief, using Schiff sensitivity score (SSS) and visual analog scale (VAS). Split quadrants containing teeth with DH were treated with either MS Coat ONE or Hi-Bond Universal with MBG as the functional additive. Assessments at baseline, immediately post-application, and at 1- and 2-week follow-ups used standardized stimulus protocols (air, cold, and acid). The SSS difference was the primary outcome, while the VAS difference was the secondary outcome. A mixed linear effect model performed statistical analysis. Immediate DH reduction occurred in response to air stimuli, with a significant decrease in Group HB than in Group MS (p = 0.0178). Cold stimulus reduction exhibited a gradual cumulative effect, with consistently greater reductions in Group HB than in Group MS (p ≤ 0.0377). Both groups effectively managed acidic stimuli, with no significant differences (p > 0.05). The VAS scores decreased gradually over the follow-up period (p < 0.0001). This study highlights the differential efficacy of treatments for various DH triggers and recommends specific approaches based on different stimulus types. The universal adhesive containing MBG demonstrated DH relief potential, promising efficacy identical to or superior to that of a dedicated desensitizing agent. Further research exploring the long-term efficacy and underlying mechanisms is warranted. The universal adhesive containing MBG can be adopted as an in-office desensitizing agent for DH relief. The desensitizing efficacy of universal adhesive matches or surpasses dedicated agents for air and cold stimuli.
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Affiliation(s)
- Hyun-Jung Kim
- Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, 24 Kyungheedae-ro, Dongdaemoon-gu, Seoul, 02453, South Korea
| | - Soram Oh
- Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, 24 Kyungheedae-ro, Dongdaemoon-gu, Seoul, 02453, South Korea
| | - Jiyoung Kwon
- Department of Conservative Dentistry, Kyung Hee University Dental Hospital, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, South Korea
| | - Kyoung-Kyu Choi
- Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, 24 Kyungheedae-ro, Dongdaemoon-gu, Seoul, 02453, South Korea
| | - Ji-Hyun Jang
- Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, 24 Kyungheedae-ro, Dongdaemoon-gu, Seoul, 02453, South Korea.
| | - Duck-Su Kim
- Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, 24 Kyungheedae-ro, Dongdaemoon-gu, Seoul, 02453, South Korea.
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Chen Y, Chen L, Ji T, Yu Y, Zhang T, Wang L. The purinergic receptor P2X3 promotes facial pain by activating neurons and cytokines in the trigeminal ganglion. Int Immunopharmacol 2024; 130:111801. [PMID: 38442578 DOI: 10.1016/j.intimp.2024.111801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 02/18/2024] [Accepted: 03/02/2024] [Indexed: 03/07/2024]
Abstract
The mechanism underlying allodynia/hyperalgesia caused by dental pulpitis has remained enigmatic. This investigation endeavored to characterize the influence of the purinergic receptor P2X3 on pain caused by experimental pulpitis and the mechanism involved. An experimental model of irreversible pulpitis was produced by the drilling and exposure of the dental pulp of the left upper first and second molars in rats, followed by measuring nociceptive responses in the oral and maxillofacial regions. Subsequently, neuronal activity and the expression of P2X3 and pertinent cytokines in the trigeminal ganglion (TG) were meticulously examined and analyzed. Histological evidence corroborated that significant pulpitis was produced in this model, which led to a distinct escalation in nociceptive responses in rats. The activation of neurons, coupled with the upregulated expression of c-fos, P2X3, p-p38, TNF-α and IL-1β, was identified subsequent to the pulpitis surgery within the TG. The selective inhibition of P2X3 with A-317491 effectively restrained the abnormal allodynia/hyperalgesia following the pulpitis surgery and concurrently inhibited the upregulation of p-p38, TNF-α and IL-1β within the TG. These findings suggest that the P2X3 signaling pathway plays a pivotal role in instigating and perpetuating pain subsequent to the induction of pulpitis in rats, implicating its association with the p38 MAPK signaling pathway and inflammatory factors.
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Affiliation(s)
- Yangxi Chen
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China; Department of Emergency and General Dentistry, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Liangyu Chen
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China; Department of Anesthesiology, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Tuo Ji
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China; Department of Anesthesiology, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Yuan Yu
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China; Department of Anesthesiology, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Tiejun Zhang
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China; Department of Anesthesiology, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China
| | - Li Wang
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China; Department of Anesthesiology, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China.
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Thai J, Fuller‐Jackson J, Ivanusic JJ. Using tissue clearing and light sheet fluorescence microscopy for the three-dimensional analysis of sensory and sympathetic nerve endings that innervate bone and dental tissue of mice. J Comp Neurol 2024; 532:e25582. [PMID: 38289188 PMCID: PMC10952626 DOI: 10.1002/cne.25582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 12/05/2023] [Accepted: 12/30/2023] [Indexed: 02/01/2024]
Abstract
Bone and dental tissues are richly innervated by sensory and sympathetic neurons. However, the characterization of the morphology, molecular phenotype, and distribution of nerves that innervate hard tissue has so far mostly been limited to thin histological sections. This approach does not adequately capture dispersed neuronal projections due to the loss of important structural information during three-dimensional (3D) reconstruction. In this study, we modified the immunolabeling-enabled imaging of solvent-cleared organs (iDISCO/iDISCO+) clearing protocol to image high-resolution neuronal structures in whole femurs and mandibles collected from perfused C57Bl/6 mice. Axons and their nerve terminal endings were immunolabeled with antibodies directed against protein gene product 9.5 (pan-neuronal marker), calcitonin gene-related peptide (peptidergic nociceptor marker), or tyrosine hydroxylase (sympathetic neuron marker). Volume imaging was performed using light sheet fluorescence microscopy. We report high-quality immunolabeling of the axons and nerve terminal endings for both sensory and sympathetic neurons that innervate the mouse femur and mandible. Importantly, we are able to follow their projections through full 3D volumes, highlight how extensive their distribution is, and show regional differences in innervation patterns for different parts of each bone (and surrounding tissues). Mapping the distribution of sensory and sympathetic axons, and their nerve terminal endings, in different bony compartments may be important in further elucidating their roles in health and disease.
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Affiliation(s)
- Jenny Thai
- Department of Anatomy and PhysiologyUniversity of MelbourneParkvilleVictoriaAustralia
| | | | - Jason J. Ivanusic
- Department of Anatomy and PhysiologyUniversity of MelbourneParkvilleVictoriaAustralia
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Müller M, Schmucker C, Naumann J, Schlueter N, Huber R, Lederer AK. Acupuncture in management of acute dental pain - A systematic review and meta-analysis. JAPANESE DENTAL SCIENCE REVIEW 2023; 59:114-128. [PMID: 36950225 PMCID: PMC10025006 DOI: 10.1016/j.jdsr.2023.02.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 02/16/2023] [Accepted: 02/23/2023] [Indexed: 03/12/2023] Open
Abstract
Acute dental pain is a common issue leading to dental consultation. Besides causal therapy, patients are treated with acupuncture, but efficacy in acute dental pain is still not clarified. We aimed to evaluate results of recent research to estimate the efficacy of acupuncture compared to pain-relieving approaches in treatment of acute dental pain. A systematic review of controlled trials being published between database inception and 2020 were conducted to evaluate the efficacy of acupuncture (alone or as complementary therapy) compared to local anesthesia or conventional analgesic medications in acute dental pain (intraoperatively and postoperatively) and to clarify whether acupuncture reduces the use of postoperative analgesic medications. Of 1672 publications, 23 publications met the inclusion criteria. From these, 11 randomized controlled trials (n = 668) reported on the efficacy of acupuncture on postoperative acute dental pain. Patients, who received acupuncture, showed lower pain scores postoperatively compared to sham acupuncture (Relative Risk -0.77, 95% Confidence interval -1.52 to -0.03). Overall, the results suggest a potential role of acupuncture in improving acute dental pain intraoperatively and postoperatively as well as improving the efficacy of local anesthesia, but the results are limited due to methodological shortcomings emphasizing the necessity for future high-quality research.
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Affiliation(s)
- Moritz Müller
- Center for Complementary Medicine, Department of Medicine II, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Christine Schmucker
- Institute for Evidence in Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Johannes Naumann
- European Institute for Physical Therapy and Balneology (EIPB), 79106 Freiburg, Germany
| | - Nadine Schlueter
- Hannover Medical School (MHH), Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Roman Huber
- Center for Complementary Medicine, Department of Medicine II, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Ann-Kathrin Lederer
- Center for Complementary Medicine, Department of Medicine II, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Department of General, Visceral and Transplant Surgery, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany
- Corresponding author at: Department of General, Visceral and Transplant Surgery, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany.
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Ballon Romero SS, Fuh LJ, Hung SY, Lee YC, Huang YC, Chien SY, Chen YH. Electroacupuncture exerts prolonged analgesic and neuroprotective effects in a persistent dental pain model induced by multiple dental pulp injuries: GABAergic interneurons-astrocytes interaction. Front Immunol 2023; 14:1213710. [PMID: 37954604 PMCID: PMC10639134 DOI: 10.3389/fimmu.2023.1213710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 10/03/2023] [Indexed: 11/14/2023] Open
Abstract
Pain within the trigeminal system, particularly dental pain, is poorly understood. This study aimed to determine whether single or multiple dental pulp injuries induce persistent pain, its association with trigeminal central nociceptive pathways and whether electroacupuncture (EA) provides prolonged analgesic and neuroprotective effects in a persistent dental pain model. Models of single dental pulp injury (SDPI) and multiple dental pulp injuries (MDPI) were used to induce trigeminal neuropathic pain. The signs of dental pain-related behavior were assessed using the mechanical head withdrawal threshold (HWT). Immunofluorescence and western blot protocols were used to monitor astrocyte activation, changes in apoptosis-related proteins, and GABAergic interneuron plasticity. SDPI mice exhibited an initial marked decrease in HWT from days one to 14, followed by progressive recovery from days 21 to 42. From days 49 to 70, the HWT increased and returned to the control values. In contrast, MDPI mice showed a persistent decrease in HWT from days one to 70. MDPI increased glial fibrillary acidic protein (GFAP) and decreased glutamine synthetase (GS) and glutamate transporter-1 (GLT1) expression in the Vi/Vc transition zone of the brainstem on day 70, whereas no changes in astrocytic markers were observed on day 70 after SDPI. Increased expression of cleaved cysteine-aspartic protease-3 (cleaved caspase-3) and Bcl-2-associated X protein (Bax), along with decreased B-cell lymphoma/leukemia 2 (Bcl-2), were observed at day 70 after MDPI but not after SDPI. The downregulation of glutamic acid decarboxylase (GAD65) expression was observed on day 70 only after MDPI. The effects of MDPI-induced lower HWT from days one to 70 were attenuated by 12 sessions of EA treatment (days one to 21 after MDPI). Changes in astrocytic GFAP, GS, and GLT-1, along with cleaved caspase-3, Bax, Bcl-2, and GAD65 expression observed 70 days after MDPI, were reversed by EA treatment. The results suggest that persistent dental pain in mice was induced by MDPI but not by SDPI. This effect was associated with trigeminal GABAergic interneuron plasticity along with morphological and functional changes in astrocytes. EA exerts prolonged analgesic and neuroprotective effects that might be associated with the modulation of neuron-glia crosstalk mechanisms.
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Affiliation(s)
| | - Lih-Jyh Fuh
- School of Dentistry, College of Dentistry, China Medical University, Taichung, Taiwan
| | - Shih-Ya Hung
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
- Division of Surgery, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
| | - Yu-Chen Lee
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
- Department of Acupuncture, China Medical University Hospital, Taichung, Taiwan
| | - Yu-Chuen Huang
- Department of Medical Research, China Medical University Hospital, School of Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Szu-Yu Chien
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
| | - Yi-Hung Chen
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
- Chinese Medicine Research Center, China Medical University, Taichung, Taiwan
- Department of Photonics and Communication Engineering, Asia University, Taichung, Taiwan
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Yang D, Solidum JGN, Park D. Dental Pulp Stem Cells and Current in vivo Approaches to Study Dental Pulp Stem Cells in Pulp Injury and Regeneration. J Bone Metab 2023; 30:231-244. [PMID: 37718901 PMCID: PMC10509030 DOI: 10.11005/jbm.2023.30.3.231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 08/20/2023] [Indexed: 09/19/2023] Open
Abstract
Dental pulp stem cells (DPSCs) have garnered significant interest in dental research for their unique characteristics and potential in tooth development and regeneration. While there were many studies to define their stem cell-like characteristics and osteogenic differentiation functions that are considered ideal candidates for regenerating damaged dental pulp tissue, how endogenous DPSCs respond to dental pulp injury and supply new dentin-forming cells has not been extensively investigated in vivo. Here, we review the recent progress in identity, function, and regulation of endogenous DPSCs and their clinical potential for pulp injury and regeneration. In addition, we discuss current advances in new mouse models, imaging techniques, and its practical uses and limitations in the analysis of DPSCs in pulp injury and regeneration in vivo.
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Affiliation(s)
- Dongwook Yang
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX,
USA
- Center for Skeletal Biology, Baylor College of Medicine, Houston, TX,
USA
| | - Jea Giezl Niedo Solidum
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX,
USA
- Department of Biochemistry & Molecular Biology, College of Medicine, University of the Philippines Manila, Manila,
Philippines
| | - Dongsu Park
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX,
USA
- Center for Skeletal Biology, Baylor College of Medicine, Houston, TX,
USA
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX,
USA
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Santonocito S, Donzella M, Venezia P, Nicolosi G, Mauceri R, Isola G. Orofacial Pain Management: An Overview of the Potential Benefits of Palmitoylethanolamide and Other Natural Agents. Pharmaceutics 2023; 15:pharmaceutics15041193. [PMID: 37111679 PMCID: PMC10142272 DOI: 10.3390/pharmaceutics15041193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 04/03/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
Pain is the most common symptom that dentists are confronted with, whether acute (pulpitis, acute periodontitis, post-surgery, etc.) or chronic diseases, such as periodontitis, muscle pain, temporomandibular joint (TMJ) disorders, burning mouth syndrome (BMS), oral lichen planus (OLP) and others. The success of therapy depends on the reduction in and management of pain through specific drugs, hence the need to analyze new pain medications with specific activity, which are suitable for long-term use, with a low risk of side effects and interactions with other drugs, and capable of leading to a reduction in orofacial pain. Palmitoylethanolamide (PEA) is a bioactive lipid mediator, which is synthesized in all tissues of the body as a protective pro-homeostatic response to tissue damage and has aroused considerable interest in the dental field due to its anti-inflammatory, analgesic, antimicrobial, antipyretic, antiepileptic, immunomodulatory and neuroprotective activities. It has been observed that PEA could play a role in the management of the pain of orofacial origin, including BMS, OLP, periodontal disease, tongue a la carte and temporomandibular disorders (TMDs), as well as in the treatment of postoperative pain. However, actual clinical data on the use of PEA in the clinical management of patients with orofacial pain are still lacking. Therefore, the main objective of the present study is to provide an overview of orofacial pain in its many manifestations and an updated analysis of the molecular pain-relieving and anti-inflammatory properties of PEA to understand its beneficial effects in the management of patients with orofacial pain, both neuropathic and nociceptive in nature. The aim is also to direct research toward the testing and use of other natural agents that have already been shown to have anti-inflammatory, antioxidant and pain-relieving actions and could offer important support in the treatment of orofacial pain.
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Affiliation(s)
- Simona Santonocito
- Department of General Surgery and Surgical-Medical Specialties, School of Dentistry, University of Catania, 95124 Catania, Italy
| | - Martina Donzella
- Department of General Surgery and Surgical-Medical Specialties, School of Dentistry, University of Catania, 95124 Catania, Italy
| | - Pietro Venezia
- Department of General Surgery and Surgical-Medical Specialties, School of Dentistry, University of Catania, 95124 Catania, Italy
| | - Giada Nicolosi
- Department of General Surgery and Surgical-Medical Specialties, School of Dentistry, University of Catania, 95124 Catania, Italy
| | - Rodolfo Mauceri
- Department of Surgical, Oncological, and Oral Sciences, University of Palermo, 90127 Palermo, Italy
| | - Gaetano Isola
- Department of General Surgery and Surgical-Medical Specialties, School of Dentistry, University of Catania, 95124 Catania, Italy
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Hasan A, Roome T, Wahid M, Ansari SA, Khan JA, Jilani SNA, Jawed A, Kiyani A. Expression of Toll-like receptor 2, Dectin-1, and Osteopontin in murine model of pulpitis. Clin Oral Investig 2023; 27:1177-1192. [PMID: 36205788 DOI: 10.1007/s00784-022-04732-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 10/01/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVES This in vivo animal study aimed to develop a murine model of pulpitis induced by pulp exposure with or without application of zymosan in Naval Medical Research Institute (NMRI) mice and observe expressions of Toll-like receptor (TLR)-2, TLR-4, Dectin-1, Osteopontin (OPN), tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and IL-1ß. MATERIAL AND METHODS A total of 168 NMRI mice were divided into two groups, i.e., group A (n = 84) (pulpitis induced by pulp exposure only) and group B (n = 84) (pulpitis induced by pulp exposure and zymosan application). Right maxillary molar pulps were exposed with ¼ round bur, and animals were sacrificed at 0, 6, 9, 12, 24, 48, and 72 h. The exposed teeth were obtained for real-time polymerase chain reaction (qRT-PCR) analysis and histological and immunohistochemistry (IHC) analysis. RESULTS Histological evaluation revealed a time-dependent steady increase in inflammation. Similar time-dependent increase in the expression of inflammatory cytokines was noted. Group A exhibited an increase in TLR-4, Dectin-1, and OPN at 6 h, while TLR-2 was expressed at 24 h. Group B expressed TLR-2, Dectin-1, and OPN at 9, 48, and 72 h, respectively (p ≤ 0.05). Expression of OPN and TNF-α exhibited a similar pattern in both groups. IHC also detected expression of TLR-2, Dectin-1, TLR4, and CD68 in some cells at 6 and 9 h. CONCLUSIONS NMRI mice provided for a stable pulp inflammation model. Zymosan may be used to develop pulp inflammation model and study inflammatory response towards fungal antigens. Dental pulp expressed Dectin-1 receptor. OPN and TNF-α exhibited a similar expression pattern. CLINICAL RELEVANCE Innate immunity of dental pulp is capable of detecting fungal pathogens.
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Affiliation(s)
- Arshad Hasan
- Department of Operative Dentistry, Dow Dental College, Dow University of Health Sciences, Baba-e-Urdu Road, Karachi, 74200, Pakistan.
| | - Talat Roome
- Department of Pathology, Section Molecular Pathology, Dow International Medical College, Ojha Campus, Gulzar-e-Hijri Karachi, Pakistan.,Dow Institute for Advanced Biological and Animal Research, Dow University of Health Sciences, Ojha Campus, Gulzar-e-Hijri Karachi, Pakistan
| | - Mohsin Wahid
- Department of Pathology, Dow International Medical College, Dow University of Health Sciences, Ojha Campus, Gulzar-e-Hijri Karachi, Pakistan.,Dow Research Institute of Biotechnology and Biomedical Sciences, Dow University of Health Sciences, Ojha Campus, Gulzar-e-Hijri Karachi, Pakistan
| | - Shazia Akbar Ansari
- Department of Oral Pathology, Dow Dental College, Dow University of Health Sciences, Baba-e-Urdu Road, Karachi, 74200, Pakistan
| | - Javeria Ali Khan
- Department of Operative Dentistry, Dow Dental College, Dow University of Health Sciences, Baba-e-Urdu Road, Karachi, 74200, Pakistan
| | - Syeda Neha Ahmed Jilani
- Dow Institute for Advanced Biological and Animal Research, Dow University of Health Sciences, Ojha Campus, Gulzar-e-Hijri Karachi, Pakistan
| | - Abira Jawed
- Department of Oral Pathology, Dow Dental College, Dow University of Health Sciences, Baba-e-Urdu Road, Karachi, 74200, Pakistan
| | - Amber Kiyani
- Department of Oral Diagnosis and Medicine, Islamic International Dental College, Riphah International University, 7th Avenue G-7/4, Islamabad, Pakistan
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11
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Shang Y, Li Y, Yang Z, Zhou Z. Upregulation of TACAN in the trigeminal ganglion affects pain transduction in acute pulpitis. Arch Oral Biol 2022; 143:105530. [PMID: 36088852 DOI: 10.1016/j.archoralbio.2022.105530] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 07/28/2022] [Accepted: 08/23/2022] [Indexed: 11/02/2022]
Abstract
OBJECTIVE Acute pulpitis is one of the common causes of tooth pain. TACAN (Tmem120a) is a newly identified ion channel that senses mechanical pain. In this experiment, we studied the expression of the TACAN ion channel in the trigeminal ganglia in a rat model of pulpitis to explore the correlation between the expression of this ion channel and inflammatory pain. DESIGN Lipopolysaccharide was used to induce acute pulpitis in rats, and pulpitis was assessed histologically. The facial pain threshold of the rats was measured by the von Frey test. TACAN mRNA expression in rat dental pulp and the trigeminal nerve was measured by qPCR, and TACAN protein expression in the trigeminal ganglia was evaluated by western blot analysis and immunofluorescence. Antisense oligonucleotides were used to reduce TACAN protein expression in the trigeminal ganglia, and the change in the pain threshold in the rats with acute pulpitis was determined. RESULTS The results showed that the TACAN transcript level in rat pulp tissue increased under inflammatory conditions, and we proved that pulpitis increased TACAN protein expression in the rat ipsilateral trigeminal ganglia. The facial pain threshold was decreased in rats with pulpitis. A short-term decrease in TACAN protein expression could improve the pain threshold. CONCLUSIONS With the development of pulpitis after bacterial infection, the upregulation of TACAN expression in the trigeminal ganglia promoted pain sensitivity. A short-term reduction in TACAN expression relieved pain. Therefore, this study indicated that TACAN is a potential target channel for new analgesics.
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Affiliation(s)
- Yicong Shang
- College of Stomatology, Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China; Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Yueheng Li
- College of Stomatology, Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China; Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Zhengyan Yang
- College of Stomatology, Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China.
| | - Zhi Zhou
- College of Stomatology, Chongqing Medical University, Chongqing, China.
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12
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Extrapolating neurogenesis of mesenchymal stem/stromal cells on electroactive and electroconductive scaffolds to dental and oral-derived stem cells. Int J Oral Sci 2022; 14:13. [PMID: 35210393 PMCID: PMC8873504 DOI: 10.1038/s41368-022-00164-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 12/29/2021] [Accepted: 01/17/2022] [Indexed: 01/06/2023] Open
Abstract
The high neurogenic potential of dental and oral-derived stem cells due to their embryonic neural crest origin, coupled with their ready accessibility and easy isolation from clinical waste, make these ideal cell sources for neuroregeneration therapy. Nevertheless, these cells also have high propensity to differentiate into the osteo-odontogenic lineage. One strategy to enhance neurogenesis of these cells may be to recapitulate the natural physiological electrical microenvironment of neural tissues via electroactive or electroconductive tissue engineering scaffolds. Nevertheless, to date, there had been hardly any such studies on these cells. Most relevant scientific information comes from neurogenesis of other mesenchymal stem/stromal cell lineages (particularly bone marrow and adipose tissue) cultured on electroactive and electroconductive scaffolds, which will therefore be the focus of this review. Although there are larger number of similar studies on neural cell lines (i.e. PC12), neural stem/progenitor cells, and pluripotent stem cells, the scientific data from such studies are much less relevant and less translatable to dental and oral-derived stem cells, which are of the mesenchymal lineage. Much extrapolation work is needed to validate that electroactive and electroconductive scaffolds can indeed promote neurogenesis of dental and oral-derived stem cells, which would thus facilitate clinical applications in neuroregeneration therapy.
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13
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Jose J, Teja K, Palanivelu A, Khandelwal A, Siddique R. Analgesic efficacy of corticosteroids and nonsteroidal anti-inflammatory drugs through oral route in the reduction of postendodontic pain: A systematic review. J Conserv Dent 2022; 25:9-19. [PMID: 35722072 PMCID: PMC9200178 DOI: 10.4103/jcd.jcd_30_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/16/2021] [Accepted: 02/19/2021] [Indexed: 11/24/2022] Open
Abstract
Analgesic medications in dentistry are indicated for the relief of acute pain, postoperative pain, chronic pain as well as controlling adjunctive intraoperative pain. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) has shown an effective reduction of postendodontic pain by action on the cyclooxygenase pathway. Another medication which is used recently is corticosteroid which enables the reduction of pain. They are hormones secreted from the adrenal gland and have strong anti-inflammatory actions. This review aims to compare the analgesic efficacy of NSAIDs and corticosteroids when administered through oral route for reducing postendodontic pain. The secondary objective was to assess the anesthetic effect of the nerve block when an oral premedication of NSAIDs or corticosteroids was administered. The databases of PubMed, ScienceDirect, LILACS, and Cochrane were searched for related topics from 1983 to April 2020. Bibliographies of clinical studies were identified in the electronic search. Clinical studies with postendodontic pain reduction using NSAIDs and corticosteroids were selected. Clinical studies that met all inclusion criteria were reviewed. Data extraction was performed independently by two reviewers. All individuals who administered single dose analgesic (NSAID or corticosteroid) before initiating root canal treatment were taken into inclusion criteria. All the relevant data were extracted from the selected studies were reviewed by two independent reviewers using a standardized data collection form, and in case of disagreement, a third reviewer was enquired to achieve a consensus. Risk of bias of the selected studies was done using Cochrane Risk of Bias Tool (version 1). Mean pain score levels at various time intervals showed an increased analgesic success rate for corticosteroids ( 32-1) in comparison to NSAIDs ( 32-21.4). Anesthetic effect of the nerve block administered was seen to be better when an oral premedication of corticosteroids (38.2%–80.8%) was given in comparison to NSAID (25.5%–73.1%). From the present study, it can be concluded that oral administration of corticosteroids provides a better analgesic efficacy when compared to NSAIDs as an oral premedication for postoperative pain reduction. It can also be concluded that corticosteroids when used as an oral premedication provide a better anesthetic effect of the nerve block administered when compared to NSAIDs given as an oral premedication. These findings could help the clinician determine which pretreatment analgesic would have a better effect in reduction of pain posttreatment as well as increasing the anesthetic efficacy of administered block. Systematic Review Registration Number: CRD42021235394.
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14
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Kwon M, Jung IY, Cha M, Lee BH. Inhibition of the Nav1.7 Channel in the Trigeminal Ganglion Relieves Pulpitis Inflammatory Pain. Front Pharmacol 2021; 12:759730. [PMID: 34955831 PMCID: PMC8694709 DOI: 10.3389/fphar.2021.759730] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 11/15/2021] [Indexed: 11/29/2022] Open
Abstract
Pulpitis causes significant changes in the peripheral nervous system, which induce hyperalgesia. However, the relationship between neuronal activity and Nav1.7 expression following pulpal noxious pain has not yet been investigated in the trigeminal ganglion (TG). The aim of our study was to verify whether experimentally induced pulpitis activates the expression of Nav1.7 peripherally and the neuronal activities of the TGs can be affected by Nav1.7 channel inhibition. Acute pulpitis was induced through allyl isothiocyanate (AITC) application to the rat maxillary molar tooth pulp. Three days after AITC application, abnormal pain behaviors were recorded, and the rats were euthanized to allow for immunohistochemical, optical imaging, and western blot analyses of the Nav1.7 expression in the TG. A significant increase in AITC-induced pain-like behaviors and histological evidence of pulpitis were observed. In addition, histological and western blot data showed that Nav1.7 expressions in the TGs were significantly higher in the AITC group than in the naive and saline group rats. Optical imaging showed that the AITC group showed higher neuronal activity after electrical stimulation of the TGs. Additionally, treatment of ProTxII, selective Nav1.7 blocker, on to the TGs in the AITC group effectively suppressed the hyperpolarized activity after electrical stimulation. These findings indicate that the inhibition of the Nav1.7 channel could modulate nociceptive signal processing in the TG following pulp inflammation.
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Affiliation(s)
- Minjee Kwon
- Department of Nursing, Kyungil University, Gyeongsan, South Korea
| | - Il Young Jung
- Department of Conservative Dentistry and Oral Science Research Center, Yonsei University College of Dentistry, Seoul, South Korea
| | - Myeounghoon Cha
- Department of Physiology, Yonsei University College of Medicine, Seoul, South Korea
| | - Bae Hwan Lee
- Department of Physiology, Yonsei University College of Medicine, Seoul, South Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
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15
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Lee PR, Lee JH, Park JM, Oh SB. Upregulation of Toll-like Receptor 2 in Dental Primary Afferents Following Pulp Injury. Exp Neurobiol 2021; 30:329-340. [PMID: 34737238 PMCID: PMC8572661 DOI: 10.5607/en21018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 10/23/2021] [Accepted: 10/24/2021] [Indexed: 11/19/2022] Open
Abstract
Pulpitis (toothache) is a painful inflammation of the dental pulp and is a prevalent problem throughout the world. This pulpal inflammation occurs in the cells inside the dental pulp, which have host defense mechanisms to combat oral microorganisms invading the pulp space of exposed teeth. This innate immunity has been well studied, with a focus on Toll-like receptors (TLRs). The function of TLR4, activated by Gram-negative bacteria, has been demonstrated in trigeminal ganglion (TG) neurons for dental pain. Although Gram-positive bacteria predominate in the teeth of patients with caries and pulpitis, the role of TLR2, which is activated by Gram-positive bacteria, is poorly understood in dental primary afferent (DPA) neurons that densely innervate the dental pulp. Using Fura-2 based Ca2+ imaging, we observed reproducible intracellular Ca2+ responses induced by Pam3CSK4 and Pam2CSK4 (TLR2-specific agonists) in TG neurons of adult wild-type (WT) mice. The response was completely abolished in TLR2 knock-out (KO) mice. Single-cell RT-PCR detected Tlr2 mRNA in DPA neurons labeled with fluorescent retrograde tracers from the upper molars. Using the mouse pulpitis model, real-time RT-PCR revealed that Tlr2 and inflammatory-related molecules were upregulated in injured TG, compared to non-injured TG, from WT mice, but not from TLR2 KO mice. TLR2 protein expression was also upregulated in injured DPA neurons, and the change was corresponded with a significant increase in calcitonin gene-related peptide (CGRP) expression. Our results provide a better molecular understanding of pulpitis by revealing the potential contribution of TLR2 to pulpal inflammatory pain.
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Affiliation(s)
- Pa Reum Lee
- Department of Neurobiology and Physiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea
| | - Jin-Hee Lee
- Department of Neurobiology and Physiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea
| | - Ji Min Park
- Department of Neurobiology and Physiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea
| | - Seog Bae Oh
- Department of Neurobiology and Physiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea
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16
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17
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Current Concepts of Dentinal Hypersensitivity. J Endod 2021; 47:1696-1702. [PMID: 34302871 DOI: 10.1016/j.joen.2021.07.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/13/2021] [Accepted: 07/13/2021] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Although many clinical studies have reported on the prevalence of dental pain, far fewer studies have focused on the mechanisms of dental pain. This is an important gap because increased understanding of dental pain mechanisms may lead to improved diagnostic tests or therapeutic interventions. The aim of this study was to comprehensively review the literature on the mechanisms of dentinal sensitivity. METHODS PubMed and Ovid were searched for articles that addressed dentinal pain and or pulpal sensitivity. Because of the breadth of research ranging from cellular/molecular studies to clinical trials, a narrative review on the mechanisms of dentinal sensitivity was constructed based on the literature. RESULTS Five various mechanisms for dentinal sensitivity have been proposed: (1) the classic hydrodynamic theory, (2) direct innervation of dentinal tubules, (3) neuroplasticity and sensitization of nociceptors, (4) odontoblasts serving as sensory receptors, and (5) algoneurons. CONCLUSIONS These theories are not mutually exclusive, and it is possible that several of them contribute to dentinal sensitivity. Moreover, pulpal responses to tissue injury may alter the relative contribution of these mechanisms. For example, pulpal inflammation may lead to neuronal sprouting and peripheral sensitization. Knowledge of these mechanisms may prompt the development of therapeutic drugs that aim to disrupt these mechanisms, leading to more effective treatments for pulpal pain.
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18
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Byers MR, Calkins DF. Trigeminal sensory nerve patterns in dentine and their responses to attrition in rat molars. Arch Oral Biol 2021; 129:105197. [PMID: 34146928 DOI: 10.1016/j.archoralbio.2021.105197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 06/03/2021] [Accepted: 06/08/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Our goal was to define trigeminal nerve ending quantities and patterns in rat molar dentine, their responses to attrition (tooth wear), and their associated odontoblasts and connections with pulpal plexuses. DESIGN Trigeminal ganglia were labeled for axonal transport of 3H-proteins to dentinal nerve endings in male rats (3-13 months old). Autoradiography detected radio-labeled dentinal tubules as indicators of nerve ending locations. Quantitative morphometry was done (ANOVA, t-tests), and littermates were compared for attrition and innervation. RESULTS There were six dentinal patterns, only two of which had an associated neural plexus of Raschkow and cell-free zone (Den-1, Den-2). Other nerves entered dentin from bush-like endings near elongated odontoblasts (Den-B), as single fibers (Den-X), as networks in predentine (PdN), or as single fibers in tertiary dentine at cusp tips (Den-S). There were at least 186,600 innervated dentinal tubules within the set of three right maxillary molars of the best-labeled rat, and similar densities were found in other rats. Attrition levels differed among cusps and in littermates (t-test p < 0.02-0.0001), but the matched right/left cusps per rat were similar. Innervations of tertiary and enamel-free dentine (Den-S, Den-X) were preserved in all rats. Den-B and Den-2 coronal patterns were unchanged unless displaced by dentinogenesis. Den-1 losses occurred in older cusps, while Den-2 patterns increased near cervical and intercuspal odontoblasts. CONCLUSIONS The extensive molar dentinal innervation had unique distributions per rat per cusp that depended on region (buccal, middle, palatal) and attrition, but only two of six patterns connected to a plexus of Raschkow.
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Affiliation(s)
- Margaret R Byers
- Department of Anesthesiology and Pain Medicine, Univ. Washington, Seattle, WA, 98195-6540, USA.
| | - Dianne F Calkins
- Department of Anesthesiology and Pain Medicine, Univ. Washington, Seattle, WA, 98195-6540, USA
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19
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Ma Z, Zhou M, Wang L, Cheng Q, Hong J. Establishment of Pulp Damage Repair Models in Miniature Pigs Using Diode Lasers. PHOTOBIOMODULATION PHOTOMEDICINE AND LASER SURGERY 2021; 39:369-377. [PMID: 33885356 DOI: 10.1089/photob.2020.4959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Objective: To establish a controlled pulp damage repair model in miniature pigs by using a diode laser. Background: Laser is a novel kind of controllable energy, and it is widely used in dentistry. Methods: The premolars of four 24- to 28-month-old miniature pigs were divided into three laser groups, according to the output powers of a diode laser, and the nonirradiated first molars acted as controls. The teeth in laser groups were irradiated under three parameters (output powers 1.5, 2.5, 4 W, continuous wave, frequency 50 Hz for 60 sec). The dental and gingival morphology was observed at 0, 7, 14, and 21 days after laser irradiation. The animals were sacrificed for qualitative and quantitative pulp histopathological analysis. Results: The three laser groups present no seriously irreversible dental and gingival damage. In the 1.5-W group, dental pulp exhibited angiectasis and hyperemia with no inflammation, and did not significantly differ with the control groups at 21 days (p > 0.05). In the 2.5-W group, pulpal inflammation was highest at 7 days and then decreased significantly at 21 days, and the tissue repair appeared at 14 days (p < 0.05). In the 4-W group, pulpal inflammation was significantly highest at 7 days, with an increase in the degree of tissue repair (p < 0.05). Conclusions: The output power of 1.5 W developed a reversible pulpitis model; the output powers of 2.5 and 4 W within 7 days led to the development of irreversible pulpitis models, which proceeded as chronic pulpitis with obvious tissue repair.
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Affiliation(s)
- Zhifei Ma
- Stomatology Special Consultation Clinic, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,National Clinical Research Center for Oral Disease, Shanghai, China.,Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China
| | - Mengqi Zhou
- National Clinical Research Center for Oral Disease, Shanghai, China.,Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China.,Department of Second Dental Clinic, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lizhen Wang
- National Clinical Research Center for Oral Disease, Shanghai, China.,Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China.,Department of Oral Pathology, and Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qing Cheng
- National Clinical Research Center for Oral Disease, Shanghai, China.,Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China.,Department of Endodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jin Hong
- Stomatology Special Consultation Clinic, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,National Clinical Research Center for Oral Disease, Shanghai, China.,Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China
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20
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Murano H, Kaneko T, Zaw SYM, Sone PP, Zaw ZCT, Okada Y, Sunakawa M, Katsube KI, Okiji T. Pulp inflammation induces Kv1.1 K + channel down-regulation in rat thalamus. Oral Dis 2021; 28:1674-1681. [PMID: 33811796 DOI: 10.1111/odi.13866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 03/07/2021] [Accepted: 03/16/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVES Signals from inflamed tooth pulp activate thalamic neurons to evoke central sensitization. We aimed to gain insights into the mechanisms mediating the early phase of pulpal inflammation-induced thalamic neural and glial activation. MATERIALS AND METHODS Pulpal inflammation was induced via the application of mustard oil (MO) to the upper first molar of Wistar rats with local anesthesia (LA) or saline injection. After 0.5, 1, 2, and 24 hr, contralateral thalami were subjected to microarrays, a real-time polymerase chain reaction and immunohistochemistry to identify differentially expressed genes and assess potassium voltage-gated channel subfamily A member 1 (Kv1.1)-expressing axons and glial fibrillary acidic protein (GFAP)-expressing astrocytes. RESULTS The Kv1.1 gene (Kcna1) was down-regulated and the density of Kv1.1-expressing axons decreased in non-anesthetized rats, but not in anesthetized rats 1 hr after the MO treatment. The density of GFAP-expressing astrocytes increased in both groups until 24 hr after the MO treatment, with a greater increase being observed in the saline-injection group than in the LA group. CONCLUSIONS MO induced the transient down-regulation of Kcna1, transiently reduced the density of Kv1.1-expressing axons, and increased astrocytes in thalami within 1 hr of pulpal application. These results suggest central sensitization represented by neuronal hyperexcitability and astrocyte activation.
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Affiliation(s)
- Hiroki Murano
- Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Tomoatsu Kaneko
- Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Su Yee Myo Zaw
- Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Phyo Pyai Sone
- Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Zar Chi Thein Zaw
- Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Yamato Okada
- Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Mitsuhiro Sunakawa
- Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | | | - Takashi Okiji
- Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
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21
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Sasaki JI, Abe GL, Li A, Matsumoto T, Imazato S. Large three-dimensional cell constructs for tissue engineering. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2021; 22:571-582. [PMID: 34408551 PMCID: PMC8366663 DOI: 10.1080/14686996.2021.1945899] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Much research has been conducted on fabricating biomimetic biomaterials in vitro. Tissue engineering approaches are often conducted by combining cells, scaffolds, and growth factors. However, the degradation rate of scaffolds is difficult to control and the degradation byproducts occasionally limit tissue regeneration. To overcome these issues, we have developed a novel system using a thermo-responsive hydrogel that forms scaffold-free, three-dimensional (3D) cell constructs with arbitrary size and morphology. 3D cell constructs prepared using bone marrow-derived stromal stem cells (BMSCs) exhibited self-organizing ability and formed bone-like tissue with endochondral ossification. Endothelial cells were then introduced into the BMSC construct and a vessel-like structure was formed within the constructs. Additionally, the bone formation ability was promoted by endothelial cells and cell constructs could be freeze-dried to improve their clinical application. A pre-treatment with specific protein protectant allowed for the fabrication of novel bone substitutes composed only of cells. This 3D cell construct technology using thermo-responsive hydrogels was then applied to other cell species. Cell constructs composed of dental pulp stem cells were fabricated, and the resulting construct regenerated pulp-like tissue within a human pulpless tooth. In this review, we demonstrate the approaches for the in vitro fabrication of bone and dental pulp-like tissue using thermo-responsive hydrogels and their potential applications.
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Affiliation(s)
- Jun-Ichi Sasaki
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Gabriela L Abe
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Aonan Li
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Takuya Matsumoto
- Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Satoshi Imazato
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry, Suita, Japan
- Department of Advanced Functional Materials Science, Osaka University Graduate School of Dentistry, Suita, Japan
- CONTACT Satoshi Imazato Department of Biomaterials Science, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
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22
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Koh W, Lim H, Chen X. Atypical triggers in trigeminal neuralgia: the role of A-delta sensory afferents in food and weather triggers. Korean J Pain 2021; 34:66-71. [PMID: 33380569 PMCID: PMC7783845 DOI: 10.3344/kjp.2021.34.1.66] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 11/05/2022] Open
Abstract
Background Trigeminal neuralgia is a debilitating craniofacial pain syndrome that is characterized by paroxysms of intense, short-lived electric shock-like pains in the trigeminal nerve distribution. Recently, the presence of triggers has become one of the key diagnostic criteria in the 3rd edition of the International Classification of Headache Disorders. Light touch is the most common trigger, however other non-mechanical triggers, such as cold weather and certain foods, have been thought to provoke trigeminal neuralgia anecdotally. We aimed to characterize the prevalence and characteristics of these atypical triggers. Methods We conducted a retrospective, cross-sectional study of atypical triggers in trigeminal neuralgia patients seen in a tertiary pain clinic in Singapore. Patients were recruited via clinic records, and study data were identified from physician documentation. Results A total of 60 patients met the inclusion criteria. Weather triggers were observed in 12 patients (20%), of which five patients (8%) reported strong winds, 4 patients (7%) reported cold temperatures, and 3 patients (5%) reported cold winds as triggers. Fifteen patients (25%) had a specific food trigger, of which 10 patients (17%) reported hard or tough food, 5 patients (8%) reported hot/cold food, 4 patients (7%) reported spicy food, and 2 patients (3%) reported sweet food as triggers. Conclusions Although trigeminal neuralgia is most commonly triggered by mechanical stimuli, atypical triggers such as cold temperatures and certain foods are seen in a significant proportion of patients. These atypical triggers may share a common pathway of sensory afferent Aδ fiber activation.
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Affiliation(s)
- Wenjun Koh
- Department of Anaesthesiology, Singapore General Hospital, Singapore
| | - Huili Lim
- Department of Anaesthesiology, Singapore General Hospital, Singapore
| | - Xuanxuan Chen
- Department of Anaesthesiology, Singapore General Hospital, Singapore
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23
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Effect of intracanal cryotherapy application on postoperative endodontic pain: a systematic review and metaanalysis. Clin Oral Investig 2020; 25:23-35. [PMID: 33222053 DOI: 10.1007/s00784-020-03693-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 11/10/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVES To assess the influence of intracanal cryotherapy application on postoperative pain after endodontic treatment. MATERIALS AND METHODS A systematic review (SR) was conducted in seven databases. Articles that were published up to 04 February 2020 were included and randomized clinical trials that used a cold saline solution for final irrigation to manage postoperative endodontic pain were compared with those that used a saline solution at room temperature. Metaanalysis was performed to assess postoperative pain after 6, 24, 48, and 72 h using a random effects model, a confidence interval of 95%, and heterogeneity tested by the I2 index. The certainty of evidence was rated using GRADE. RESULTS Qualitative and quantitative analysis included eight and six studies, respectively. Individuals treated with cryotherapy presented lower means of postendodontic pain than the controls, 6 and 24 h after endodontic treatment (MD - 1.30 [- 2.32, - 0.28] p = 0.01 and SMD - 0.68 [ - 1.21, - 0.16] p = 0.01, respectively, with very low certainty of evidence). After 48 and 72 h, both groups demonstrated similar means of postendodontic pain (MD - 0.06 [- 0.18, 0.07] p = 0.38 and SMD - 0.54 [- 1.18, - 0.11] p = 0.10, with high and low certainty of evidence, respectively). CONCLUSIONS Based on the limited quality evidence, intracanal cryotherapy application reduced postoperative endodontic pain after 6 and 24 h. New clinical trials are needed to support the result of this review. CLINICAL SIGNIFICANCE This SR provides information about the use of intracanal cryotherapy in clinical practice, guides clinicians to make evidence-based decisions and suggests recommendations for further high-quality studies.
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Kanno K, Shimizu K, Shinoda M, Hayashi M, Takeichi O, Iwata K. Role of macrophage-mediated Toll-like receptor 4-interleukin-1R signaling in ectopic tongue pain associated with tooth pulp inflammation. J Neuroinflammation 2020; 17:312. [PMID: 33081813 PMCID: PMC7576725 DOI: 10.1186/s12974-020-01995-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 10/08/2020] [Indexed: 01/16/2023] Open
Abstract
Background The existence of referred pain and ectopic paresthesia caused by tooth pulp inflammation may make definitive diagnosis difficult and cause misdiagnosis or mistreatment; thus, elucidation of that molecular mechanism is urgent. In the present study, we investigated the mechanisms underlying ectopic pain, especially tongue hyperalgesia, after tooth pulp inflammation. Methods A rat model with mandibular first molar tooth pulp exposure was employed. Tooth pulp exposure-induced heat and mechanical-evoked tongue hypersensitivity was measured, and immunohistochemical staining for Iba1, a marker of active macrophages, IL-1β, IL-1 type I receptor (IL-1RΙ), and toll-like receptor 4 in the trigeminal ganglion was performed. In addition, we investigated the effects of injections of liposomal clodronate Clophosome-A (LCCA), a selective macrophage depletion agent, lipopolysaccharide from Rhodobacter sphaeroides (LPS-RS, a toll-like receptor 4 antagonist), IL-1β, or heat shock protein 70 (Hsp70, a selective agonist of toll-like receptor 4), to examine changes in tongue hypersensitivity and in the regulation of IL-1RΙ, toll-like receptor 4, and transient receptor potential vanilloid 1 (TRPV1) biosynthesis. Results At day 1 after tooth pulp exposure, obvious tooth pulp inflammation was observed. Tooth pulp exposure-induced heat and mechanical tongue hypersensitivity was observed from days 1 to 3 after tooth pulp exposure. The production of IL-1β in activated macrophages and toll-like receptor 4 and IL-1RΙ expression were significantly increased in trigeminal ganglion neurons innervating the tongue following tooth pulp exposure. Intra-trigeminal ganglion injection of LCCA significantly suppressed tongue hypersensitivity; however, toll-like receptor 4 and IL-1RΙ expression in trigeminal ganglion neurons innervating the tongue was not significantly altered. Intra-trigeminal ganglion injection of LPS-RS significantly suppressed tongue hypersensitivity and reduced IL-1RΙ expression in the trigeminal ganglion neurons innervating the tongue following tooth pulp exposure. Intra-trigeminal ganglion injection of recombinant Hsp70 significantly promoted tongue hypersensitivity and increased IL-1RI expression in trigeminal ganglion neurons innervating the tongue in naive rats. Furthermore, intra-trigeminal ganglion injection of recombinant IL-1β led to tongue hypersensitivity and enhanced TRPV1 expression in trigeminal ganglion neurons innervating the tongue in naive rats. Conclusions The present findings suggest that the neuron-macrophage interaction mediated by toll-like receptor 4 and IL-1RI activation in trigeminal ganglion neurons affects the pathogenesis of abnormal tongue pain following tooth pulp inflammation via IL-1RI and TRPV1 signaling in the trigeminal ganglion. Further research may contribute to the establishment of new therapeutic and diagnostic methods.
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Affiliation(s)
- Kohei Kanno
- Department of Endodontics, Nihon University School of Dentistry, 1-8-13 Kandasurugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Kohei Shimizu
- Department of Endodontics, Nihon University School of Dentistry, 1-8-13 Kandasurugadai, Chiyoda-ku, Tokyo, 101-8310, Japan. .,Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan.
| | - Masamichi Shinoda
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan.,Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
| | - Makoto Hayashi
- Department of Endodontics, Nihon University School of Dentistry, 1-8-13 Kandasurugadai, Chiyoda-ku, Tokyo, 101-8310, Japan.,Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
| | - Osamu Takeichi
- Department of Endodontics, Nihon University School of Dentistry, 1-8-13 Kandasurugadai, Chiyoda-ku, Tokyo, 101-8310, Japan.,Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
| | - Koichi Iwata
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan.,Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
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Rechenberg DK, Munir A, Zehnder M. Correlation between the clinically diagnosed inflammatory process and periapical index scores in severely painful endodontically involved teeth. Int Endod J 2020; 54:172-180. [PMID: 32918280 PMCID: PMC7894281 DOI: 10.1111/iej.13407] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/03/2020] [Accepted: 09/03/2020] [Indexed: 11/28/2022]
Abstract
Aim To assess and correlate three distinct states of severely painful endodontically derived inflammation with their depiction on periapical radiographs using periapical index (PAI) scores. Methodology During a period of 15 months, 368 consecutively enrolled patients with suspected endodontic emergency conditions were examined at the University of Zurich, Center of Dental Medicine. Cases with a severely painful (numeric rating scale, NRS‐11 > 6) endodontically involved tooth and a clear pulpal and apical diagnosis (n = 162) were selected (one tooth per patient). Teeth were divided into three groups according to the clinically diagnosed main location of the inflammatory process: level 1: pulp (positive response to cold test), level 2: periodontium (no response to cold without swelling) and level 3: periapical tissues (no response to cold with swelling). Periapical radiographs were obtained using a digital unit and analysed by two calibrated observers. For level 2, which had the highest PAI variance (n = 76), the PAI scores were further scrutinized regarding their dependence on tooth location and the duration of pain. Data were analysed using chi‐squared and non‐parametric tests, alpha = 0.05. Results Overall, the PAI scores correlated well with the clinically diagnosed main location of periapical inflammation (Spearman’s rho = 0.5131, P < 0.001), with level 1 having the lowest scores by far (P < 0.001) and level 2 having significantly lower scores compared to level 3 (P < 0.05). However, a PAI score of 5 was found in merely 3 teeth within the entire cohort, and 49% of the teeth in the level 2 group had no radiolucency (PAI < 3). Within level 2, the PAI scores were not dependent on tooth location but were substantially (P < 0.001) higher for teeth which had hurt for more than one week, and for root filled teeth. Conclusions For the analysed, severely painful endodontically involved teeth, the clinically diagnosed main location of inflammation was reflected by the periapical index. PAI scores were not significantly influenced by anatomical noise, yet in some cases under‐estimated the clinical situation.
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Affiliation(s)
- D K Rechenberg
- Division of Endodontology, Clinic of Conservative and Preventive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - A Munir
- Division of Endodontology, Clinic of Conservative and Preventive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - M Zehnder
- Division of Endodontology, Clinic of Conservative and Preventive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
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Allison JR, Stone SJ, Pigg M. The painful tooth: mechanisms, presentation and differential diagnosis of odontogenic pain. ACTA ACUST UNITED AC 2020. [DOI: 10.1111/ors.12481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- J. R. Allison
- School of Dental Sciences Faculty of Medical Sciences Newcastle University Newcastle upon Tyne UK
| | - S. J. Stone
- School of Dental Sciences Faculty of Medical Sciences Newcastle University Newcastle upon Tyne UK
| | - M. Pigg
- Department of Endodontics Faculty of Odontology Scandinavian Centre for Orofacial Neurosciences (SCON) Malmö University Malmö Sweden
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Abstract
Over the past century, there is perhaps no greater contribution to the practice of clinical dentistry than the development and application of local anaesthesia. What were once considered painful procedures have now been made routine by the deposition and action of local anaesthetics. This article will serve as a review of basic pharmacological principles of local anaesthesia, subsequent sequelae that can arise from their use, considerations when using local anaesthetics, and recent advances in the delivery of local anaesthetics.
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Affiliation(s)
- Derek Decloux
- Discipline of Dental Anaesthesia, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Aviv Ouanounou
- Department of Clinical Sciences (Pharmacology & Preventive Dentistry), Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
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28
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Sone PP, Kaneko T, Zaw SYM, Sueyama Y, Gu B, Murano H, Zaw ZCT, Okada Y, Han P, Katsube KI, Okiji T. Neural Regeneration/Remodeling in Engineered Coronal Pulp Tissue in the Rat Molar. J Endod 2020; 46:943-949. [DOI: 10.1016/j.joen.2020.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 03/10/2020] [Accepted: 04/03/2020] [Indexed: 12/25/2022]
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29
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Filippini HF, Molska GR, Zanjir M, Arudchelvan Y, Gong SG, Campos MM, Avivi-Arber L, Sessle BJ. Toll-Like Receptor 4 in the Rat Caudal Medulla Mediates Tooth Pulp Inflammatory Pain. Front Neurosci 2020; 14:643. [PMID: 32655361 PMCID: PMC7324534 DOI: 10.3389/fnins.2020.00643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 05/25/2020] [Indexed: 12/20/2022] Open
Abstract
The aims of this study were to investigate if Toll-like receptor 4 (TLR4) is expressed in the medullary dorsal horn (MDH) and if medullary application of a TLR4 antagonist (lipopolysaccharides from Rhodobacter sphaeroides, LPS-RS) can attenuate changes in nociceptive sensorimotor responses or TLR4 expression that might be evoked by mustard oil (MO) application to the right maxillary first molar tooth pulp. Of 41 adult male Sprague-Dawley rats used in the study, 23 received intrathecal application of the TLR4 antagonist LPS-RS (25 μg/10 μl; LPS-RS group) or isotonic saline (10 μl; vehicle control group) 10 min before pulpal application of MO (95%; 0.2 μl). Bilateral electromyographic (EMG) activities of the anterior digastric and masseter muscles were recorded continuously before and until 15 min after the MO application to the pulp. In 6 of these 23 rats and an additional 18 rats, the caudal medulla containing the ipsilateral and contralateral MDH was removed after euthanasia for subsequent Western Blot analysis of TLR4 expression in LPS-RS (n = 8) and vehicle (n = 8) groups and a naïve group (n = 8). The % change from baseline in the MO-evoked EMG activities within the anterior digastric muscles were significantly smaller in the LPS-RS group than the control group (two-way ANOVA, post hoc Bonferroni, P < 0.0001). Western Blot analysis revealed similar levels of TLR4 expression in the caudal medulla of the naïve, vehicle and LPS-RS groups. These novel findings suggest that TLR4 signaling in the caudal medulla may mediate MO-induced acute dental inflammatory pain in rats.
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Affiliation(s)
- Helena F Filippini
- Programa de Pós-graduação em Odontologia, Escola de Ciência da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.,Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | | | - Maryam Zanjir
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | | | - Siew-Ging Gong
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Maria M Campos
- Programa de Pós-graduação em Odontologia, Escola de Ciência da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.,Centro de Pesquisa em Toxicologia e Farmacologia, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Limor Avivi-Arber
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.,Centre for the Study of Pain, University of Toronto, Toronto, ON, Canada
| | - Barry J Sessle
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.,Centre for the Study of Pain, University of Toronto, Toronto, ON, Canada.,Departament of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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Ballon Romero SS, Lee YC, Fuh LJ, Chung HY, Hung SY, Chen YH. Analgesic and Neuroprotective Effects of Electroacupuncture in a Dental Pulp Injury Model-A Basic Research. Int J Mol Sci 2020; 21:E2628. [PMID: 32283868 PMCID: PMC7178196 DOI: 10.3390/ijms21072628] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/02/2020] [Accepted: 04/05/2020] [Indexed: 12/18/2022] Open
Abstract
Irreversible pulpitis is an extremely painful condition and its consequence in the central nervous system (CNS) remains unclear. A mouse model of dental pulp injury (DPI) resembles the irreversible pulpitis profile in humans. This study sought to determine whether pain induced by DPI activates microglia and astrocytes in the trigeminal subnucleus caudalis (Vc), as well as increases levels of proinflammatory cytokines, and whether electroacupuncture (EA) can be a potential analgesic and neuroprotective therapy following DPI. Pain behavior was measured via head-withdrawal threshold (HWT) and burrowing behavior at days 1, 3, 7, 14 and 21 after DPI. A marked decrease in HWT and burrowing activity was observed from day 1 to 14 after DPI and no changes were seen on day 21. Microglial and astrocytes activation; along with high cytokine (TNFα, IL-1β, and IL-6) levels, were observed in the Vc at 21 days after DPI. These effects were attenuated by verum (local and distal) EA, as well as oral ibuprofen administration. The results suggest that DPI-induced pain and glial activations in the Vc and EA exert analgesic efficacy at both local and distal acupoints. Furthermore, verum (local and distal) EA might be associated with the modulations of microglial and astrocytes activation.
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Affiliation(s)
- Sharmely Sharon Ballon Romero
- Graduate Institute of Acupuncture Science, China Medical University, Taichung 40402, Taiwan; (S.S.B.R.); (Y.-C.L.); (H.-Y.C.); (S.-Y.H.)
| | - Yu-Chen Lee
- Graduate Institute of Acupuncture Science, China Medical University, Taichung 40402, Taiwan; (S.S.B.R.); (Y.-C.L.); (H.-Y.C.); (S.-Y.H.)
- Department of Acupuncture, China Medical University Hospital, Taichung 40447, Taiwan
- Chinese Medicine Research Center, China Medical University, Taichung 40402, Taiwan
| | - Lih-Jyh Fuh
- School of Dentistry, College of Dentistry, China Medical University; Taichung 40402, Taiwan;
| | - Hsin-Yi Chung
- Graduate Institute of Acupuncture Science, China Medical University, Taichung 40402, Taiwan; (S.S.B.R.); (Y.-C.L.); (H.-Y.C.); (S.-Y.H.)
| | - Shih-Ya Hung
- Graduate Institute of Acupuncture Science, China Medical University, Taichung 40402, Taiwan; (S.S.B.R.); (Y.-C.L.); (H.-Y.C.); (S.-Y.H.)
- Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan
| | - Yi-Hung Chen
- Graduate Institute of Acupuncture Science, China Medical University, Taichung 40402, Taiwan; (S.S.B.R.); (Y.-C.L.); (H.-Y.C.); (S.-Y.H.)
- Chinese Medicine Research Center, China Medical University, Taichung 40402, Taiwan
- Department of Photonics and Communication Engineering, Asia University, Taichung 41354, Taiwan
- Brain Disease Research Center, China Medical University Hospital, Taichung 40447, Taiwan
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Mellor DJ. Mouth Pain in Horses: Physiological Foundations, Behavioural Indices, Welfare Implications, and a Suggested Solution. Animals (Basel) 2020; 10:ani10040572. [PMID: 32235343 PMCID: PMC7222381 DOI: 10.3390/ani10040572] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 03/26/2020] [Accepted: 03/26/2020] [Indexed: 12/14/2022] Open
Abstract
Simple Summary Mouth pain in horses, specifically that caused by bits, is evaluated as a significant welfare issue. The conscious experiences of pain generated within the body generally, its roles, and its assessment using behaviour, as well as the sensory functionality of the horse’s mouth, are outlined as background to a more detailed evaluation of mouth pain. Bit-induced mouth pain elicited by compression, laceration, inflammation, impeded blood flow, and the stretching of tissues is considered. Observable signs of mouth pain are behaviours that are present in bitted horses and absent or much less prevalent when they are bit-free. It is noted that many equestrians do not recognise that these behaviours indicate mouth pain, so that the magnitude of the problem is often underestimated. The negative experiences that are most responsible for welfare compromise include the pain itself, but also, related to this pain, potentially intense breathlessness, anxiety, and fear. Finally, a series of questions is proposed to clarify issues that are relevant to increasing the adoption of bit-free bridles in order to avoid bit-induced mouth pain. Abstract A proposition addressed here is that, although bitted horses are viewed by many equestrians as being largely free of bit-related mouth pain, it seems likely that most behavioural signs of such pain are simply not recognised. Background information is provided on the following: the major features of pain generation and experience; cerebrocortical involvement in the conscious experience of pain by mammals; the numerous other subjective experiences mammals can have; adjunct physiological responses to pain; some general feature of behavioural responses to pain; and the neural bases of sensations generated within the mouth. Mouth pain in horses is then discussed. The areas considered exclude dental disease, but they include the stimulation of pain receptors by bits in the interdental space, the tongue, the commissures of the mouth, and the buccal mucosa. Compression, laceration, inflammation, impeded tissue blood flow, and tissue stretching are evaluated as noxious stimuli. The high pain sensitivity of the interdental space is described, as are likely increases in pain sensitivity due to repeated bit contact with bruises, cuts, tears, and/or ulcers wherever they are located in the mouth. Behavioural indices of mouth pain are then identified by contrasting the behaviours of horses when wearing bitted bridles, when changed from bitted to bit-free bridles, and when free-roaming unbitted in the wild. Observed indicative behaviours involve mouth movements, head-neck position, and facial expression (“pain face”), as well as characteristic body movements and gait. The welfare impacts of bit-related pain include the noxiousness of the pain itself as well as likely anxiety when anticipating the pain and fear whilst experiencing it, especially if the pain is severe. In addition, particular mouth behaviours impede airflow within the air passages of the upper respiratory system, effects that, in their turn, adversely affect the air passages in the lungs. Here, they increase airflow resistance and decrease alveolar gas exchange, giving rise to suffocating experiences of breathlessness. In addition, breathlessness is a likely consequence of the low jowl angles commonly maintained during dressage. If severe, as with pain, the prospect of breathlessness is likely to give rise to anxiety and the direct experience of breathlessness to fear. The related components of welfare compromise therefore likely involve pain, breathlessness, anxiety, and fear. Finally, a 12-point strategy is proposed to give greater impetus to a wider adoption of bit-free bridles in order to avoid bit-induced mouth pain.
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Affiliation(s)
- David J Mellor
- Animal Welfare Science and Bioethics Centre, School of Veterinary Science, Massey University, Palmerston North 4474, New Zealand
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Mohaved SB, Shilpa G, Li Q, Austah O, Bendele M, Brock R, Ruparel NB. Apical periodontitis-induced mechanical allodynia: A mouse model to study infection-induced chronic pain conditions. Mol Pain 2020; 16:1744806919900725. [PMID: 31902318 PMCID: PMC6977224 DOI: 10.1177/1744806919900725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Infection-induced chronic pain is an under-studied pain condition. One example is apical periodontitis, which evokes considerable mechanical allodynia that persists after treatment in 7% to 12% of patients. Available analgesics often provide incomplete relief. However, a preclinical model to study pain mechanisms associated with apical periodontitis is not available. Here, we report a mouse model of apical periodontitis to facilitate studies determining mechanisms mediating persistent infection-induced pain. Mice were anesthetized and the left first molar was exposed to the oral environment for six weeks. Bone resorption, as an indicator of apical periodontitis, was quantified using microcomputed tomography. Mechanical allodynia was determined using extraoral von-Frey filaments in both male and female mice. The expression of c-fos in the medullary dorsal horn was assessed using immunohistochemistry. Mice with apical periodontitis developed significant mechanical allodynia by day 7 that was maintained for 42 days. Mechanical thresholds were significantly lower in females compared to males. Administration of ibuprofen, morphine, or MK-801 reversed mechanical allodynia. Finally, apical periodontitis triggered an upregulation of c-fos in the medullary dorsal horn. Collectively, this model simulates signs of clinical pain experienced by patients with apical periodontitis, detects sex differences in allodynia, and permits the study of peripheral and central trigeminal pain mechanisms.
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Affiliation(s)
- Saeed B Mohaved
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Ganatra Shilpa
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Qun Li
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Obadah Austah
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Michelle Bendele
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Robert Brock
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Nikita B Ruparel
- Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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Rajan S, Ljunggren A, Manton DJ, Björkner AE, McCullough M. Post-mitotic odontoblasts in health, disease, and regeneration. Arch Oral Biol 2019; 109:104591. [PMID: 31710968 DOI: 10.1016/j.archoralbio.2019.104591] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 10/09/2019] [Accepted: 10/20/2019] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Description of the odontoblast lifecycle, an overview of the known complex molecular interactions that occur when the health of the dental pulp is challenged and the current and future management strategies on vital and non-vital teeth. METHODS A literature search of the electronic databases included MEDLINE (1966-April 2019), CINAHL (1982-April 2019), EMBASE and EMBASE Classic (1947-April 2019), and hand searches of references retrieved were undertaken using the following MESH terms 'odontoblast*', 'inflammation', 'dental pulp*', 'wound healing' and 'regenerative medicine'. RESULTS Odontoblasts have a sensory and mechano-transduction role so as to detect external stimuli that challenge the dental pulp. On detection, odontoblasts stimulate the innate immunity by activating defence mechanisms key in the healing and repair mechanisms of the tooth. A better understanding of the role of odontoblasts within the dental pulp complex will allow an opportunity for biological management to remove the cause of the insult to the dental pulp, modulate the inflammatory process, and promote the healing and repair capabilities of the tooth. Current strategies include use of conventional dental pulp medicaments while newer methods include bioactive molecules, epigenetic modifications and tissue engineering. CONCLUSION Regenerative medicine methods are in their infancy and experimental stages at best. This review highlights the future direction of dental caries management and consequently research.
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Affiliation(s)
- S Rajan
- The University of Melbourne, Australia.
| | | | - D J Manton
- The University of Melbourne, Australia; Centrum voor Tandheelkunde en Mondzorgkunde, UMCG, University of Groningen, the Netherlands
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Histologic Evaluation of Regenerated Tissues in the Pulp Spaces of Teeth with Mature Roots at the Time of the Regenerative Endodontic Procedures. J Endod 2019; 45:1384-1389. [PMID: 31515046 DOI: 10.1016/j.joen.2019.07.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 07/23/2019] [Accepted: 07/28/2019] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Recently, regenerative endodontic procedures (REPs) have been used to treat mature permanent teeth with apical periodontitis. Although animal studies with regard to histopathological findings after REPs exist, there is a paucity of studies on mature human teeth. As yet, the nature of tissues formed in the root canal of such teeth has not been established. This report presents histologic findings with regard to regenerative tissues in the pulp spaces exposed after dental trauma in human mature maxillary incisor teeth successfully treated with REPs. METHODS A 20-year-old girl was referred to our clinic for the treatment of her central incisors (#8 and #9). The incisors had apical periodontitis. REPs were performed on both maxillary central incisors. Three years 5 months after the initial treatment, the teeth had a horizontal crown fracture and needed a fiber post as well as root canal treatment. Mineral trioxide aggregate was carefully removed, and the tissue that had formed in the canal space was processed for routine histologic and immunohistochemical examination. RESULTS Histologic findings of the present case showed that the vital tissue formed in the canal space was fibrous connective tissue that contains bonelike tissue, vascular structures, and inflammation. These histologic findings obtained from mature teeth were similar to the findings of previous reports relating to immature teeth. CONCLUSIONS Based on the present case, the vital tissue formed in the canal space is fibrous connective tissue that contains bonelike tissue, vascular structures, and inflammation. These histologic findings with regard to mature teeth were similar to the findings of previous reports relating to immature teeth.
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Voyta LL, Zazhigin VS, Petrova EA, Krjutchkova LY. Shrew dentition (Lipotyphla: Soricidae)—endodontic morphology and its phylogenetic resolving power. MAMMAL RES 2019. [DOI: 10.1007/s13364-019-00455-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Byers MR. Chewing causes rapid changes in immunoreactive nerve patterns in rat molar teeth: Implications for dental proprioception and pain. Arch Oral Biol 2019; 107:104511. [PMID: 31445382 DOI: 10.1016/j.archoralbio.2019.104511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 07/19/2019] [Accepted: 07/28/2019] [Indexed: 01/06/2023]
Abstract
OBJECTIVE This study tests the hypothesis that normal use of teeth (chewing) causes changes in immunoreactive-(IR) patterns for endings of large Aβ and CGRP axons in rat molar cusps. DESIGN First, a new paradigm to test chewing in adult male rats was developed. Then IR patterns for large dental axons were analysed for a calcium-binding protein, parvalbumin (PV), heavy neurofilament protein-200 (NFP), and vesicle-release molecule synaptophysin (SYN) that all typify large dental axons and proprioceptors for comparison with endings of CGRP-IR neuropeptide axons. The behavior groups were: (1) daytime sleeping/fasting (Group:SF); (2) brief feeding after 8-11 h of daytime sleeping/fasting (Group:SF-C); (3) normal nocturnal feeding (Group:N); (4) nocturnal fasting (Group:NF); (5) brief feeding/chewing after nocturnal fasting (Group:NF-C). RESULTS Nerve endings with NFP-, PV-, or SYN-IR were lost or altered in pulp and dentin in all chewing groups. Other endings with CGRP-IR were near those with PV-, NFP- and SYN-IR at the pulp-dentin border and in dentin, and they also lost immunoreactivity in all chewing groups. The special beaded regions along the crown pulp/dentin borders lost neural labeling in all chewing groups. Nerves of molar roots and periodontal ligament were not changed. CONCLUSIONS Rapid neural reactions to chewing show extensive, reversible, non-nociceptive depletions of crown innervation. Those changes were rapid enough to occur during normal feeding followed by recovery during rest. The new dental paradigm related to chewing and fasting allows dissection of intradental proprioceptive-like mechanisms during normal tooth functions for comparison with nociceptive and mechanosensitive reactions after injury or inflammation.
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Affiliation(s)
- Margaret R Byers
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, 98195-6540 USA.
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Lee K, Lee BM, Park CK, Kim YH, Chung G. Ion Channels Involved in Tooth Pain. Int J Mol Sci 2019; 20:ijms20092266. [PMID: 31071917 PMCID: PMC6539952 DOI: 10.3390/ijms20092266] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 05/03/2019] [Accepted: 05/03/2019] [Indexed: 01/05/2023] Open
Abstract
The tooth has an unusual sensory system that converts external stimuli predominantly into pain, yet its sensory afferents in teeth demonstrate cytochemical properties of non-nociceptive neurons. This review summarizes the recent knowledge underlying this paradoxical nociception, with a focus on the ion channels involved in tooth pain. The expression of temperature-sensitive ion channels has been extensively investigated because thermal stimulation often evokes tooth pain. However, temperature-sensitive ion channels cannot explain the sudden intense tooth pain evoked by innocuous temperatures or light air puffs, leading to the hydrodynamic theory emphasizing the microfluidic movement within the dentinal tubules for detection by mechanosensitive ion channels. Several mechanosensitive ion channels expressed in dental sensory systems have been suggested as key players in the hydrodynamic theory, and TRPM7, which is abundant in the odontoblasts, and recently discovered PIEZO receptors are promising candidates. Several ligand-gated ion channels and voltage-gated ion channels expressed in dental primary afferent neurons have been discussed in relation to their potential contribution to tooth pain. In addition, in recent years, there has been growing interest in the potential sensory role of odontoblasts; thus, the expression of ion channels in odontoblasts and their potential relation to tooth pain is also reviewed.
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Affiliation(s)
- Kihwan Lee
- Gachon Pain Center and Department of Physiology, College of Medicine, Gachon University, Incheon 406-799, Korea.
| | - Byeong-Min Lee
- Department of Oral Physiology and Program in Neurobiology, School of Dentistry, Seoul National University, Seoul 08826, Korea.
| | - Chul-Kyu Park
- Gachon Pain Center and Department of Physiology, College of Medicine, Gachon University, Incheon 406-799, Korea.
| | - Yong Ho Kim
- Gachon Pain Center and Department of Physiology, College of Medicine, Gachon University, Incheon 406-799, Korea.
| | - Gehoon Chung
- Department of Oral Physiology and Program in Neurobiology, School of Dentistry, Seoul National University, Seoul 08826, Korea.
- Dental Research Institute, Seoul National University, Seoul 03080, Korea.
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Nav1.7 via Promotion of ERK in the Trigeminal Ganglion Plays an Important Role in the Induction of Pulpitis Inflammatory Pain. BIOMED RESEARCH INTERNATIONAL 2019; 2019:6973932. [PMID: 31032358 PMCID: PMC6458889 DOI: 10.1155/2019/6973932] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 02/17/2019] [Indexed: 12/19/2022]
Abstract
The trigeminal ganglion (TG) refers to sensory neurons bodies that innervate the spinal cord and peripheral axons that innervate teeth. The tetrodotoxin-sensitive sodium (NA) channels (Nav1.7) play important roles in the pathophysiology of pain. In this study, we investigated the TG expression of Nav1.7 and extracellular signal-regulated kinase (ERK) in a rat model of pulpitis to explore the correlation between these channels and inflammatory pain. Pulpitis was confirmed by hematoxylin-eosin staining. In this study, we demonstrated that the reflex of rats to mechanical stimulation increases after pulp exposure and that the exposed rat molar pulp can upregulate the expression of Nav1.7 and ERK in the rat TG. Three days after rat pulp exposure, the expression levels of the two ion channels in the TG increased. TG target injection of PF04856264, a Nav1.7 inhibitor, dose-dependently increased the mechanical pain threshold and was able to inhibit ERK expression. TG target injection of PD98059, an ERK inhibitor, dose-dependently increased the mechanical pain threshold. These factors simultaneously resulted in the highest production. In this study, with the established link to inflammatory pain, we found that Nav1.7 and ERK both play important roles in the induction of inflammatory pain caused by pulpitis. We also found a correlation between the expression levels of Nav1.7 and ERK and the degree of inflammatory pain. Furthermore, ERK signaling pathways were promoted by the Nav1.7 in TG after pulpitis.
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Hossain MZ, Bakri MM, Yahya F, Ando H, Unno S, Kitagawa J. The Role of Transient Receptor Potential (TRP) Channels in the Transduction of Dental Pain. Int J Mol Sci 2019; 20:ijms20030526. [PMID: 30691193 PMCID: PMC6387147 DOI: 10.3390/ijms20030526] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/18/2019] [Accepted: 01/24/2019] [Indexed: 12/18/2022] Open
Abstract
Dental pain is a common health problem that negatively impacts the activities of daily living. Dentine hypersensitivity and pulpitis-associated pain are among the most common types of dental pain. Patients with these conditions feel pain upon exposure of the affected tooth to various external stimuli. However, the molecular mechanisms underlying dental pain, especially the transduction of external stimuli to electrical signals in the nerve, remain unclear. Numerous ion channels and receptors localized in the dental primary afferent neurons (DPAs) and odontoblasts have been implicated in the transduction of dental pain, and functional expression of various polymodal transient receptor potential (TRP) channels has been detected in DPAs and odontoblasts. External stimuli-induced dentinal tubular fluid movement can activate TRP channels on DPAs and odontoblasts. The odontoblasts can in turn activate the DPAs by paracrine signaling through ATP and glutamate release. In pulpitis, inflammatory mediators may sensitize the DPAs. They could also induce post-translational modifications of TRP channels, increase trafficking of these channels to nerve terminals, and increase the sensitivity of these channels to stimuli. Additionally, in caries-induced pulpitis, bacterial products can directly activate TRP channels on DPAs. In this review, we provide an overview of the TRP channels expressed in the various tooth structures, and we discuss their involvement in the development of dental pain.
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Affiliation(s)
- Mohammad Zakir Hossain
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan.
| | - Marina Mohd Bakri
- Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Farhana Yahya
- Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Hiroshi Ando
- Department of Biology, School of Dentistry, Matsumoto Dental University, 1780 Gobara, Hirooka, Shiojiri, Nagano 399-0781, Japan.
| | - Shumpei Unno
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan.
| | - Junichi Kitagawa
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan.
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Fuks AB, Kupietzky A, Guelmann M. Pulp Therapy for the Primary Dentition. Pediatr Dent 2019. [DOI: 10.1016/b978-0-323-60826-8.00023-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Filippini HF, Scalzilli PA, Costa KM, Freitas RDS, Campos MM. Activation of trigeminal ganglion satellite glial cells in CFA-induced tooth pulp pain in rats. PLoS One 2018; 13:e0207411. [PMID: 30419075 PMCID: PMC6231674 DOI: 10.1371/journal.pone.0207411] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 10/30/2018] [Indexed: 02/07/2023] Open
Abstract
This study further investigated the mechanisms underlying the rat model of tooth pulp inflammatory pain elicited by complete Freund's adjuvant (CFA), in comparison to other pulpitis models. Pulps of the left maxillary first molars were accessed. In the CFA group, the pulps were exposed, and CFA application was followed by dental sealing. In the open group, the pulps were left exposed to the oral cavity. For the closed group, the pulps were exposed, and the teeth were immediately sealed. Naïve rats were used as negative controls. Several parameters were evaluated at 1, 2, 3 and 8 days. There was no statistical significant difference among the groups when body weight variation, food or water consumption were compared. Analysis of serum cytokines (IL-1β, TNF or IL-6) or differential blood cell counts did not reveal any evidence of systemic inflammation. The CFA group displayed a significant reduction in the locomotor activity (at 1 and 3 days), associated with an increased activation of satellite glial cells in the ipsilateral trigeminal ganglion (TG; for up to 8 days). Amygdala astrocyte activation was unaffected in any experimental groups. We provide novel evidence indicating that CFA-induced pulp inflammation impaired the locomotor activity, with persistent activation of ipsilateral TG satellite cells surrounding sensory neurons, without any evidence of systemic inflammation or amygdala astrogliosis.
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Affiliation(s)
- Helena F. Filippini
- Programa de Pós-graduação em Odontologia, Escola de Ciências da Saúde, PUCRS, Porto Alegre, RS, Brasil
| | - Paulo A. Scalzilli
- Laboratório de Patologia, Escola de Ciência da Saúde, PUCRS, Porto Alegre, RS, Brasil
- Centro de Pesquisa em Toxicologia e Farmacologia, Escola de Ciências da Saúde, PUCRS, Porto Alegre, RS, Brasil
| | - Kesiane M. Costa
- Programa de Pós-graduação em Medicina e Ciências da Saúde, Escola de Medicina, PUCRS, Porto Alegre, RS, Brasil
| | - Raquel D. S. Freitas
- Centro de Pesquisa em Toxicologia e Farmacologia, Escola de Ciências da Saúde, PUCRS, Porto Alegre, RS, Brasil
- Programa de Pós-graduação em Medicina e Ciências da Saúde, Escola de Medicina, PUCRS, Porto Alegre, RS, Brasil
| | - Maria M. Campos
- Programa de Pós-graduação em Odontologia, Escola de Ciências da Saúde, PUCRS, Porto Alegre, RS, Brasil
- Laboratório de Patologia, Escola de Ciência da Saúde, PUCRS, Porto Alegre, RS, Brasil
- Centro de Pesquisa em Toxicologia e Farmacologia, Escola de Ciências da Saúde, PUCRS, Porto Alegre, RS, Brasil
- Programa de Pós-graduação em Medicina e Ciências da Saúde, Escola de Medicina, PUCRS, Porto Alegre, RS, Brasil
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Juárez I, Morales-Medina JC, Flores-Tochihuitl J, Juárez GS, Flores G, Oseki HC. Tooth pulp injury induces sex-dependent neuronal reshaping in the ventral posterolateral nucleus of the rat thalamus. J Chem Neuroanat 2018; 96:16-21. [PMID: 30391473 DOI: 10.1016/j.jchemneu.2018.10.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/18/2018] [Accepted: 10/20/2018] [Indexed: 02/06/2023]
Abstract
Orofacial injuries often result in persistent pain and are therefore considered a common health problem worldwide. Considerable evidence suggests that peripheral sensory nerve injury results in diverse plastic changes in the central nervous system (CNS). Tooth pulp is innervated by trigeminal afferents which extend to the trigeminal brainstem sensory nuclear complex and send input to higher level neurons in the CNS, including the ventral posterolateral nucleus of the thalamus (VPL). In the present study, we examined the long term effects of pulpal injury on neuronal arborization in the VPL using morphological analysis via Golgi-Cox staining. In addition, we examined these effects in both male and female rats due to the major prevalence of oral pain in women. Quantitative morphological analysis revealed that pulpal injury induced neuronal hypertrophy in VPL neurons of female rats. In clear contrast, pulpal injury increased arborization close to the soma and reduced arborization distal to the soma without modification of total dendritic length in male rats. As a result, we show, for the first time, sex-dependent morphological alterations in VPL neurons after orofacial peripheral injury. Since dental injuries are readily reproducible in rat dental molars and closely mimic the clinical setting in humans, this model represents a useful tool to further understand mechanisms of orofacial pain.
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Affiliation(s)
- Ismael Juárez
- Laboratorio de Fisiología, Facultad de Estomatología, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico
| | - Julio César Morales-Medina
- Centro de Investigación en Reproducción Animal, CINVESTAV-Universidad Autónoma de Tlaxcala, Tlaxcala, AP 62, 90000, Mexico
| | - Julia Flores-Tochihuitl
- Laboratorio Multidisciplinario, Facultad de Estomatología, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico
| | - Gamaliel Santiago Juárez
- Laboratorio de Fisiología, Facultad de Estomatología, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico
| | - Gonzalo Flores
- Laboratorio Neuropsiquiatría, Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla 72570, Mexico
| | - Hortencia Chávez Oseki
- Laboratorio de Fisiología, Facultad de Estomatología, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico.
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Racich MJ. Occlusion, temporomandibular disorders, and orofacial pain: An evidence-based overview and update with recommendations. J Prosthet Dent 2018; 120:678-685. [DOI: 10.1016/j.prosdent.2018.01.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/25/2018] [Accepted: 01/25/2018] [Indexed: 12/13/2022]
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44
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Cuoghi OA, Faria LPD, Ervolino E, Barioni SRP, Topolski F, Arana-Chavez VE, Mendonça MRD. Pulp analysis of teeth submitted to different types of forces: a histological study in rats. J Appl Oral Sci 2018; 26:e20170626. [PMID: 30304125 PMCID: PMC6172023 DOI: 10.1590/1678-7757-2017-0626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 06/25/2018] [Indexed: 11/24/2022] Open
Abstract
Objective: The purpose of this study was to histologically evaluate pulp and dentin under induced tooth movement (ITM) with different types of forces. Material and Methods: The maxillary right first molars of rats were submitted to movement with continuous (CF), continuous interrupted (CIF) and intermittent (IF) forces during 5, 7 and 9 days with nickel-titanium (NiTi) closed-coil springs exerting 50cN force magnitude. The groups were histologically evaluated as for cellularity pattern, presence of dystrophic, hemodynamic alterations in the pulp as well dentin alterations. The main observed alterations were related to hemodynamic pulp characteristics, such as presence of thrombosis, vascular congestion and hemorrhages. The hemodynamic alterations were statistically evaluated by Shapiro-Wilk normality test and analysis of variance by the Kruskall-Wallis test. Results: There was no significant differences observed between groups in the different types of applied forces and duration of ITM (vascular congestion, p=1.000; hemorrhage, p=0.305; thrombosis, p=1.000). Conclusions: Pulp tissue alterations resulting from ITM were limited to hemodynamic events, without progressing to irreversible degeneration, regardless of the type of force applied.
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Affiliation(s)
- Osmar Aparecido Cuoghi
- Univ. Estadual Paulista, Faculdade de Odontologia de Araçatuba, Departamento de Odontologia Infantil e Social, Araçatuba, São Paulo, Brasil
| | - Lorraine Perciliano de Faria
- Universidade de São Paulo, Faculdade de Odontologia, Departamento de Biomateriais e Biologia Oral, São Paulo, São Paulo, Brasil
| | - Edilson Ervolino
- Univ. Estadual Paulista, Faculdade de Odontologia de Araçatuba, Departamento de Ciências Básicas, Araçatuba, São Paulo, Brasil
| | - Sônia Regina Panzarini Barioni
- Univ. Estadual Paulista, Faculdade de Odontologia de Araçatuba, Departamento de Cirurgia e Clínica Integrada, Araçatuba, São Paulo, Brasil
| | - Francielle Topolski
- Univ. Estadual Paulista, Faculdade de Odontologia de Araçatuba, Departamento de Odontologia Infantil e Social, Araçatuba, São Paulo, Brasil
| | - Victor Elias Arana-Chavez
- Universidade de São Paulo, Faculdade de Odontologia, Departamento de Biomateriais e Biologia Oral, São Paulo, São Paulo, Brasil
| | - Marcos Rogério de Mendonça
- Univ. Estadual Paulista, Faculdade de Odontologia de Araçatuba, Departamento de Odontologia Infantil e Social, Araçatuba, São Paulo, Brasil
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Mahdee A, Eastham J, Whitworth JM, Gillespie JI. Evidence for changing nerve growth factor signalling mechanisms during development, maturation and ageing in the rat molar pulp. Int Endod J 2018; 52:211-222. [DOI: 10.1111/iej.12997] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 08/06/2018] [Indexed: 11/27/2022]
Affiliation(s)
- A. Mahdee
- Centre for Oral Health Research; Newcastle University; Newcastle upon Tyne UK
- Institute of Cellular Medicine; Newcastle University; Newcastle upon Tyne UK
- School of Dental Sciences; Newcastle University; Newcastle upon Tyne UK
- University of Baghdad College of Dentistry; Baghdad Iraq
| | - J. Eastham
- Institute of Cellular Medicine; Newcastle University; Newcastle upon Tyne UK
| | - J. M. Whitworth
- Centre for Oral Health Research; Newcastle University; Newcastle upon Tyne UK
- School of Dental Sciences; Newcastle University; Newcastle upon Tyne UK
| | - J. I. Gillespie
- School of Dental Sciences; Newcastle University; Newcastle upon Tyne UK
- Urology and Urological Rehabilitation; Antwerp University; Antwerp Belgium
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Dabiri D, Harper DE, Kapila Y, Kruger GH, Clauw DJ, Harte S. Applications of sensory and physiological measurement in oral-facial dental pain. SPECIAL CARE IN DENTISTRY 2018; 38:395-404. [PMID: 30194771 PMCID: PMC6282998 DOI: 10.1111/scd.12323] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/01/2018] [Accepted: 08/05/2018] [Indexed: 12/01/2022]
Abstract
Dentists regularly employ a variety of self‐report and sensory techniques to aid in the diagnosis and treatment of tooth‐related disease. Many of these techniques leverage principles borrowed from psychophysics, the quantitative measurement of the relationship between stimuli and evoked sensations, which falls under the larger umbrella of quantitative sensory testing (QST). However, most clinicians fail to meet the bar for what could be considered quantitative sensory testing, and instead focus on qualitative and dichotomous “yes/no” aspects of sensory experience. With our current subjective measurements for pain assessments, diagnosis and treatment of dental pain in young children and individuals (any age) with severe cognitive impairment rely extensively on third‐party observations. Consequently, the limitation of inadequate pain diagnosis can lead to poor pain management. In this review, it discusses mechanisms that underlie acute and chronic dental pain. It details the measurement of somatosensory responses and pulpal blood flow as objective measures of tooth health and pain. It proposes that bridging these varied methodologies will significantly improve diagnosis and treatment of orofacial pain and pathology. It concludes that improving the precision of sensory measurements could yield important improvements in diagnostic challenges in pulpal pathology for noncommunicative and cognitively impaired individuals.
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Affiliation(s)
- Darya Dabiri
- Chronic Pain & Fatigue Research Center, Department of Anesthesiology, University of Michigan Medicine, Ann Arbor, Michigan
| | - Daniel E Harper
- Chronic Pain & Fatigue Research Center, Department of Anesthesiology, University of Michigan Medicine, Ann Arbor, Michigan
| | - Yvonne Kapila
- Division of Periodontology, Department of Orofacial Sciences, University of California San Francisco, San Francisco, California
| | - Grant H Kruger
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan
| | - Daniel J Clauw
- Chronic Pain & Fatigue Research Center, Department of Anesthesiology, University of Michigan Medicine, Ann Arbor, Michigan
| | - Steven Harte
- Chronic Pain & Fatigue Research Center, Department of Anesthesiology, University of Michigan Medicine, Ann Arbor, Michigan
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Bae JY, Mun CJ, Kim YS, Ahn DK, Bae YC. Quantitative ultrastructural analysis of fibers expressing parvalbumin, calretinin, calbindin D-28k, stage specific embryonic antigen-4, and phosphorylated neurofilament 200 in the peripheral sensory root of the rat trigeminal ganglion. J Comp Neurol 2018; 526:2204-2214. [DOI: 10.1002/cne.24476] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 04/02/2018] [Accepted: 05/14/2018] [Indexed: 11/07/2022]
Affiliation(s)
- Jin Young Bae
- Department of Anatomy and Neurobiology, School of Dentistry; Kyungpook National University; Daegu South Korea
| | - Cheol Ju Mun
- Department of Anatomy and Neurobiology, School of Dentistry; Kyungpook National University; Daegu South Korea
| | - Yun Sook Kim
- Department of Anatomy and Neurobiology, School of Dentistry; Kyungpook National University; Daegu South Korea
| | - Dong Kuk Ahn
- Department of Physiology, School of Dentistry; Kyungpook National University; Daegu South Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry; Kyungpook National University; Daegu South Korea
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Zampino C, Ficacci R, Checcacci M, Franciolini F, Catacuzzeno L. Pain Control by Proprioceptive and Exteroceptive Stimulation at the Trigeminal Level. Front Physiol 2018; 9:1037. [PMID: 30131708 PMCID: PMC6090166 DOI: 10.3389/fphys.2018.01037] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/12/2018] [Indexed: 11/25/2022] Open
Abstract
The Gate Control Theory of pain, published more than half a century ago to explain nociceptive modulation of peripheral sensory input, assumes inhibition of incoming nociceptive (pain) information produced by mechanical stimulation. To verify the presence of such a gate control mechanism at the level of the human trigeminal system, we evaluated the effects on pain sensation of a proprioceptive trigeminal stimulation induced by mandibular extension. We found that such a stimulation, applied for 7 min, was effective in increasing both the threshold and tolerance of tooth pain induced by electrical activation of dental nociceptors. Moreover the antinociceptive effect lasted for several minutes after the proprioceptive stimulus had ceased. We also tested whether an exteroceptive palatal stimulation superimposed on the proprioceptive stimulation would increase the effects on tooth pain perception of human volunteers. We observed that the exteroceptive stimulation significantly increased the antinociceptive effect induced by the sole proprioceptive stimulation. The physiological mechanisms and the possible implications of these observations are discussed.
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Affiliation(s)
- Claudio Zampino
- Department of Chemistry, Biology and Biotechnology, The University of Perugia, Perugia, Italy
| | - Roberta Ficacci
- Department of Chemistry, Biology and Biotechnology, The University of Perugia, Perugia, Italy
| | | | - Fabio Franciolini
- Department of Chemistry, Biology and Biotechnology, The University of Perugia, Perugia, Italy
| | - Luigi Catacuzzeno
- Department of Chemistry, Biology and Biotechnology, The University of Perugia, Perugia, Italy
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49
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Yu CY, Abbott PV. Pulp microenvironment and mechanisms of pain arising from the dental pulp: From an endodontic perspective. AUST ENDOD J 2018. [DOI: 10.1111/aej.12257] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Christine Y. Yu
- Discipline of Endodontics; UWA Dental School; Oral Health Centre of Western Australia; The University of Western Australia (M512); Crawley Western Australia Australia
| | - Paul V. Abbott
- Discipline of Endodontics; UWA Dental School; Oral Health Centre of Western Australia; The University of Western Australia (M512); Crawley Western Australia Australia
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50
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Chmilewsky F, About I, Cooper LF, Chung SH. C5L2 Silencing in Human Pulp Fibroblasts Enhances Nerve Outgrowth Under Lipoteichoic Acid Stimulation. J Endod 2018; 44:1396-1401. [PMID: 30032862 DOI: 10.1016/j.joen.2018.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/18/2018] [Accepted: 05/03/2018] [Indexed: 01/09/2023]
Abstract
INTRODUCTION We recently reported that caries-associated C5a receptor (C5aR) expression and activation result in up-regulation of brain-derived neurotropic factor secretion by pulp fibroblasts inducing prominent neurite outgrowth toward the carious site. Our data further showed a negative regulation of this brain-derived neurotropic factor secretion by C5L2, another C5aR. C5L2 was considered a nonfunctional receptor and thus has received much less attention than C5aR. The aim of this study was to identify the role of C5L2 in pulp fibroblast-mediated neurite outgrowth. METHODS In this study, lipoteichoic acid (LTA) was used to mimic dental caries-like inflammation. To evaluate the role of C5L2 in pulp neurite outgrowth, human pulp fibroblasts were C5L2 small interfering RNA silenced and cocultured with human neurons in a nerve growth assay system. RESULTS C5L2 silencing drastically increased the neurite outgrowth toward the LTA-stimulated pulp fibroblasts. The number of neurites detected was increased in the LTA-treated pulp fibroblasts. CONCLUSIONS Our results show that C5L2 constitutes a negative regulator of the neurite outgrowth under LTA stimulation. Of the events occurring during dentin-pulp regeneration, nerve regeneration is the key factor for maintaining tooth viability after infection or injury. Our study provides a foundation for creating therapeutic tools that target pulp fibroblasts during pulp/nerve regeneration.
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Affiliation(s)
- Fanny Chmilewsky
- Department of Oral Biology, University of Illinois at Chicago, Chicago, Illinois
| | - Imad About
- Department of Oral Biology, Aix Marseille University, Marseille, France
| | - Lyndon F Cooper
- Department of Oral Biology, University of Illinois at Chicago, Chicago, Illinois
| | - Seung H Chung
- Department of Oral Biology, University of Illinois at Chicago, Chicago, Illinois.
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