Inferior alveolar nerve injury resulting from overextension of an endodontic sealer: non-surgical management using the GABA analogue pregabalin

Periapically Extruded Calcium Silicate Cements in Retreated Teeth: A Case Report and Literature Review

Calcium silicate-based materials, known for their bioactive properties, are increasingly being used in endodontic therapy. Accidental extrusion of these materials into the periapical tissue is a relatively common phenomenon that can impede periapical healing. The aim of this article is to present three endodontically retreated case reports with moderate to extensive periapical lesions and to review the literature on this topic. The comprehensive search and analysis of the relevant literature included a review of 51 articles, of which nine case reports/series from 2010 to 2023 were considered. Based on the summarized data, over 80% of the retreated cases showed complete healing of the periapical lesions, while the success rate in initially treated teeth was over 90%. Healing of periapical lesions is the most common therapeutic outcome, even in cases where extrusion occurs. Despite this conclusion, extrusion of materials into periapical tissues should be avoided. Further case reports on the extrusion of calcium silicate-based materials other than MTA are recommended. When evaluating the success rate of periapical healing in such cases, it is recommended to extend the follow-up periods to several years.

Resolution of apical periodontitis-induced mental nerve paresthesia through non-surgical endodontic retreatment: a case report

INTRODUCTION

Paresthesia is a potential consequence of unsuccessful root canal treatment. Persistent infection resulting in apical periodontitis may enlarge sufficiently to involve the mental neurovascular bundle.

METHODS

The case presented in this report was referred for endodontic evaluation with a chief complaint of discomfort on mastication and persistent numbness of the lower left lip. Clinical and radiographic evaluation revealed incomplete primary endodontic treatment of the left mandibular second premolar with complex internal anatomy. The untreated root canal system resulted in the progression of apical periodontitis involving the left mental neurovascular bundle as confirmed by CBCT imaging.

RESULTS

Non-surgical root canal retreatment was performed over two visits. At the 3-year follow-up visit, the paresthesia had resolved with return of normal sensation.

CONCLUSION

Non-surgical endodontic retreatment may be sufficient to allow healing of large periapical lesions and resolve complications including paresthesia without the need for surgical intervention.

Inferior alveolar nerve injury due to the extrusion of calcium hydroxide during endodontic treatment: A case report

Although many materials are used for root canal fillings in endodontic treatment, calcium hydroxide has been preferred for many years due to its bactericidal effect and biocompatibility. Calcium hydroxide can be applied in more than one form. In this case study, calcium hydroxide in viscous form, applied into the root canal during endodontic treatment, overflowed from the apical part of the tooth to the inferior alveolar nerve canal. Postoperative paraesthesia was observed in the patient. Dental volumetric tomography was performed to study the extent of sealer in the inferior alveolar nerve canal. Considering the short resorption time of the calcium hydroxide paste, no surgical intervention was performed on the patient. After 6 months, the root canal material was completely resorbed, and paraesthesia decreased. At the 3-year follow-up, the patient's paraesthesia had completely disappeared.

Assessment of the relationship of the distance between mandibular first and second molars with the inferior alveolar canal and cortical bone plate in an Egyptian subpopulation: a CBCT study

The aim of the current cone beam computed tomography (CBCT) study was to evaluate the proximity of mandibular first and second molar roots to the inferior alveolar canal (IAC) and mandibular cortex in an Egyptian subpopulation. Scans of 120 patients (480 molars, 960 roots) were obtained from the College of Dentistry database at the Suez Canal University, Egypt. Buccal and lingual bone plates and root thickness were measured at the specified resected root end 3 mm from the radiographic apex, and so was the proximity of the root apices to the IAC. Measurements of the right and left mandibular first and second molars were recorded for each root. Three examiners performed the measurements separately. ANOVA was used to compare the different roots. Bonferroni's post-hoc test was used for pair-wise comparisons when ANOVA was significant. The significance level was set at p ≤ 0.05. The findings displayed a closer proximity of the mandibular second molar apices to the IAC, as compared to the mandibular first molars. The mesial roots were at a shorter distance than the distal ones. Moreover, the mandibular second molars revealed the thickest total bone width including the root. So, it is beneficial for endodontists to be aware of the relation of the mandibular first and second molars to the surrounding cortical bone plates and the IAC before starting either nonsurgical or surgical endodontic treatment.

Endodontic remnants are found more than other radiopacities in proposed implant sites

Background

Foreign bodies may be a cause of concern in dental implant failure.

Purpose

The aim of the present study was to assess the occurrence and to evaluate the types of radiopacities in dental extraction sites using cone beam computed tomography (CBCT).

Materials and methods

The incidence, location, and types of radiopacities were evaluated in 180 CBCT scans.

Results

Different radiopaque structures could be noted in 84 scans. Foreign bodies and remaining roots were frequently seen. Most of the radiopacities were attributed to remaining endodontic filling in upper and lower jaws in 25 scans in different locations. Remaining roots could be detected in 20 scans. Focal and diffuse radiopaque bony lesions were observed in 16 scans. Tissue response in the form of radiolucency could be seen more with endodontic foreign bodies. Tissue reactions to radiopaque filling remnants were seen in 6.11% of cases.

Conclusions

Foreign body remnants, mostly of endodontic fillings, were frequently seen in CBCT in upper and lower jaws. Evidence of tissue reactions to extraction remnants could be found. Endodontic filling remnants could be seen more in the upper jaw. Thorough examination of implant site for the presence of endodontic foreign body remnants should be stressed. Debridement of the extraction socket should be done carefully in endodontically treated teeth.

Inferior alveolar nerve paraestheia and cutaneous sinus on the face associated with periapical infection of lower molar teeth in a 14-year-old girl: A rare and unusual case report

BACKGROUND

Paresthesia is defined as a burning or prickling sensation or partial numbness caused by neural injury.

OBJECTIVE

The purpose of this paper is to present a rare and unusual case report of odontogenic infection-induced inferior alveolar nerve (IAN) paresthesia along with cutaneous draining sinus on the face of a pediatric patient and to discuss the possible pathophysiologic mechanism of nerve injury.

METHODS

A 14-year-old female patient with cutaneous sinus and paresthesia associated with inferior alveolar nerve was enrolled in the study and the clinical and radiological manifestations of sinus lesion were carefully evaluated.

RESULTS

The most appropriate treatment was carried out not only to resolve extraoral sinus but also to ensure progressive healing for the complete resolution of neurological disturbance.

CONCLUSION

The simultaneous occurrence of infection and paresthesia strongly suggested a definitive relationship. Therefore, there seems to be a correlation between duration, origin, significance of the injury and the prognosis of paresthesia.

Piezosurgical management of sealer extrusion-associated mental nerve anaesthesia: A case report

The present report describes a case where sealer extrusion (Sealapex) occurred during root canal obturation of a left lower second premolar tooth, and the patient experienced sudden pain and followed by complete anaesthesia of the lower lip. After 3 weeks of conservative therapy and an unaltered anaesthesia period, piezosurgical removal of the extruded sealer and root-end resection was performed despite the direct contact with the mental neurovascular bundle. At suture removal, 1 week after surgery, there was no improvement in sensation. Two weeks after the operation, the patient reported some changes, including a short paraesthesia period alternating with anaesthesia. At the fourth post-operative week, neurosensory function recovered completely. This case represents successful use of the piezoelectric technique for mental nerve decompression and periapical surgery of a lower second premolar with close contact of the mental nerve.

Endodontic-related inferior alveolar nerve injuries: A review and a therapeutic flow chart

INTRODUCTION

Inferior alveolar nerve (IAN) lesions related to endodontic treatments can be explained by the anatomical proximity between the apices of the mandibular posterior teeth and the mandibular canal. The aim of this article is to review the management of inferior alveolar nerve lesions due to endodontic treatments and to establish a therapeutic flow chart.

METHODS

A review of publications reporting IAN damage related to endodontic treatment over the past 20 years has been conducted, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist; it combines an electronic search of the Pubmed^® and Google Scholar^® databasis. Forty-two full-text articles corresponding to 115 clinical cases have been selected. Two personal clinical cases were additionally reported.

RESULTS

IAN lesions due to endodontic treatments require urgent management. Early surgical removal of the excess of endodontic material, in contact with the nerve allows the best recovery prognosis (72h). Beyond this delay, irreversible nervous lesions prevail and a medical symptomatic treatment, most of the time with pregabalin, must be/can be carried out. A delayed surgical procedure shows some good benefits for patients. However, the healing prognosis remains poorly predictable.

A cone-beam computed tomography study of the anatomical relationships between mandibular teeth and the mandibular canal, with a review of the current literature

The purpose of this study was to evaluate age- and sex-related changes in the anatomical relationships between the roots of the molars and premolars and the mandibular canal using cone-beam computed tomography (CBCT) images. A total of 243 patients (116 males, 127 females) aged 16-83 years for whom previous CBCT scans were available were enrolled in this study. The patients were subcategorized by sex and age (Group I, <21 years; Group II, 21-40 years; and Group III, >40 years). The distances between the mandibular canal and the molars and premolars were measured. The mandibular canal was significantly closer to the root apices of the second and third molars than to the apices of other evaluated teeth (p < 0.05). All measurements were significantly higher in male than in female subjects (p < 0.05). Group I subjects exhibited significantly shorter distances between the mandibular canal and root apices of the first and second premolars, and the molars, than those of Group II and III subjects (p < 0.05). Direct contact relationships were found in 1.6%, 3.3%, 3.3%, 16%, and 32.2% of teeth (running from the first premolar to the third molar, respectively). Age and sex influenced the anatomical relationships between mandibular teeth and the mandibular canal, and these should be considered when planning endodontic and surgical procedures to avoid potential nerve injury.

Secondary surgical decompression of the inferior alveolar nerve after overfilling of endodontic sealer into the mandibular canal: Case report and literature review

The authors report the case of a 43-year-old woman who underwent endodontic treatment of the right second mandibular molar with substantial extrusion of endodontic material into the mandibular canal. The patient presented at the Department of Oral and Maxillofacial Surgery with a persistent total anaesthesia of the lower lip and chin after two months. 2D panoramic view and 3D CT-scan examination highlighted the overfilling into the mandibular canal with a more than 50% stenosis of the canal and a consequently significant compression of the dental pedicle. A surgical decompression of the inferior alveolar nerve was performed through an inferior vestibular approach, using PiezoSurgery^®. The tooth was conserved. After a period of 8days, paraesthesia of the lower lip and chin appeared. Thermoalgic sensitivity was recovered at 1month. At 3months postoperatively, the patient had recovered protopathic and epicritic sensitivity. Dental prosthetic rehabilitation was finally achieved one year postoperatively. The authors discuss the physiopathology of nervous injuries during dental procedures, and further strategies in the case of persistent neurologic disorders.

Surgical Approach to Foreign Material Within the Mandibular Canal Due to Iatrogenic Factors

This clinical report describes a relatively infrequent patient with inferior alveolar nerve damage caused by foreign material within the mandibular canal, which is one of the most severe complications of endodontic therapy. Although the circumstance is uncommon, it can have extremely unfavorable consequences for patients, such as anesthesia and paresthesia. In the present case, a patient suffered pain and severe paresthesia in the corresponding area after routine endodontic therapy. Several treatments were conducted to relieve the patient's symptoms, ranging from medication to tooth extraction, but all were of no avail. Ultimately, surgical exploration and debridement were performed with assistance of a customized surgical template. Once the foreign material was excavated, the exacerbation of condition was terminated and gradually reverted. This patient illustrates that special attention is required when undertaking intracanal procedures of lower posterior teeth so as to avoid iatrogenic damage to inferior alveolar nerve. Even more significant, when above-mentioned condition occurs, prompt surgical intervention is essential for recovery of sensation. It also demonstrates the advantages of applying surgical template and piezosurgery in removal of foreign material within the mandibular canal.

Extrusion of Root Canal Sealer in Periapical Tissues - Report of Two Cases with Different Treatment Management and Literature Review

Background: Extrusion of root canal sealers may cause damage to the surrounding anatomic structures. Clinical symptoms like pain, swelling and paresthesia or anesthesia may be present. The purpose of this presentation is to describe two cases of root canal sealer penetration into periapical tissues. A different treatment management was followed in each case.

Case reports: A 55 year-old man underwent root canal retreatment of the right mandibular first molar tooth due to a periapical lesion. Postoperative periapical radiographs revealed the presence of root canal sealer (AH26) beyond the apex in the distal root in proximity to the mandibular canal. The patient reported pain for the next 7 days. Radiographic examination after 1 year showed complete healing of the periapical area and a small absorption of the root canal sealer. A 42 year-old woman was referred complained of swelling and pain in the area of the right maxillary first incisor. Radiographic examination showed extrusion of root canal sealer in the periapical area associated with a periapical lesion. Surgical intervention was decided upon, which included removal of the sealer, apicoectomy of the tooth and retrograde filling with MTA. After 1 year, complete healing of the area was observed.

Conclusion: In conclusion, cases of root canal sealer extrusion, surgical treatment should be decided on only in association with clinical symptoms or with radiographic evidence of increasing periapical lesion.

Neurotoxicity evaluation of three root canal sealers on cultured rat trigeminal ganglion neurons

Background

The aim of this study was to investigate the possible neurotoxic effects of 3 root canal sealers (RCSs) (AH Plus, GuttaFlow, iRoot SP) on cultured rat trigeminal ganglion (TG) neurons.

Material and Methods

Primary cultures of TG neurons were obtained from 1 to 2-day old rats. Freshly mixed RCSs were incubated in sterile phosphate buffered saline and cells were incubated with supernatants of the RCSs for different time intervals (1-, 3-, 6- and 24-h; 1 or 1/10 diluted) and viability/cytotoxicity was tested by counting the number of live cells. Pair of dishes with cells from the same culture incubated with only culture medium was considered as negative controls. Cell images were captured and acquired at x200 magnification using a microscope equipped with a camera using special image program. The viable cells were manually counted assigned from the images for each dose and incubation duration. Data was analysed by using 1-way analysis of variance with Tukey post hoc tests.

Results

There was no significant change in cell viability after short duration of incubation (1- and 3-h) with the supernatant of any of RCSs, except for undiluted-AH Plus at 3-h. When AH Plus was compared with other RCSs, for diluted supernatants, there was only significant difference between iRoot SP and AH Plus at 24-h (P<0.05). Whereas undiluted-AH Plus was significantly more cytotoxic for 3-, 6- and 24-h periods as compared to respective incubation periods of undiluted other groups (P<0.05). GuttaFlow groups had similar neurotoxic effect on cells for all test periods.

Conclusions

All tested RCSs exhibited a variable degree of neurotoxicity on these primary sensory neurons of orofacial tissues, depending on their chemical compositions. GuttaFlow and iRoot SP evoked a less toxic response to TG cells than AH Plus.

Key words:Neurotoxicity, trigeminal ganglia, cell culture, root canal sealer, AH Plus, GuttaFlow, iRoot SP.

Bioactive mono-dispersed nanospheres with long-term antibacterial effects for endodontic sealing

Endodontic sealers with antibacterial capability play an important role in preventing reinfection of an endodontically treated root canal and improving the long-term success of root canal treatment. However, current endodontic sealers rapidly lose their antibacterial properties after fixation. In this work, we designed and synthesized quaternized mono-dispersed bioactive nanospheres as a potential substrate for the development of a long-term antibacterial endodontic sealer with excellent cytocompatibility and biocompatibility. First, mono-dispersed silica-based bioactive glass nanospheres (SBG-NS) were prepared via a modified sol-gel process. Next, a series of quaternary ammonium methacrylate salts (QAMs) with broad antibacterial spectra were synthesized and grafted onto the surfaces of the SBG-NS via a two-step coupling approach. The antibacterial effect of the quaternary ammonium polymethacrylate (QAPM)-containing SBG-NS (SBG-QAPM) against persistent microorganisms associated with infected root canals was evaluated using a direct contact test. Evaluations of the SBG-QAPM cytocompatibility and biocompatibility were performed using LIVE/DEAD staining, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2, 5-tetrazoliumbromide (MTT) assay, and a calvarial implantation model. The results showed that the SBG-QAPMs had the strongest long-term antibacterial effect against the Enterococcus faecalis, Streptococcus mutans, and Streptococcus sanguis during the study period, the best cytocompatibility, and the lowest systemic inflammation compared to three commercial products: ProRoot MTA, Endomethasone C, and AH Plus. In addition, the SBG-QAPMs showed excellent stability in aqueous solution. This work indicates that the SBG-QAPMs are promising substrates for the development of long-term antibacterial endodontic sealers.

Infection Related Inferior Alveolar Nerve Paresthesia in the Lower Premolar Teeth

Introduction. The aim of this paper was to describe two cases of IAN infection-induced paresthesia and to discuss the most appropriate treatment solutions. Methods. For two patients, periapical lesions that induced IAN paresthesia were revealed. In the first case, the tooth was previously endodontically treated, whereas in the second case the lesion was due to pulp necrosis. Results. For the first patient, a progressive healing was observed only after the tooth extraction. In the second patient, the paresthesia had resolved after endodontic treatment. Conclusions. The endodontic-related paresthesia is a rare complication that can be the result of a combination of etiopathogenic mechanisms such as mechanical pressure on the nerve fibers due to the expanding infectious process and the production of microbial toxins. Paresthesia resulting from periapical lesions usually subsides through elimination of infection by root canal treatment. However, if there are no signs of enhancement, the immediate extraction of the tooth is the treatment of choice in order to prevent irreversible paresthesia because it was demonstrated that there is a correlation between the duration of mechanical or chemical irritation and the risk of permanent paresthesia.

Effect of starch on the mechanical and in vitro properties of collagen-hydroxyapatite sponges for applications in dentistry

This study sought to improve the mechanical and blood-absorbing properties of collagen sponges, while keeping them compressible, by incorporating blended hydroxyapatite (HA)-starch. Results were compared with CollaPlug(®) (pure collagen). The elastic modulus increased from 1.5±0.2kPa for CollaPlug(®) to 49±8kPa for sponges with composition 1:4:10 (collagen:HA:starch, by weight). The modified microstructure and surface area provided by the starch granules on the sponges improved cell viability. Sponges with composition 1:4:10 maintained their blood-clotting capability with almost no change from 5 to 15min after contact with blood, while CollaPlug(®) diminished to about half its capacity to absorb blood and form clots. Incorporation of HA-starch into the sponges with composition of 1:4:10, increased the elastic modulus of the collagen-HA sponges, making them more structurally robust. The viability of cells and the blood-clotting capability increased with starch incorporation.

Accidental overextension of endodontic filling material in patients with neurologic complications: a retrospective case series

Accidental overextension of filling material during endodontic treatment may cause mechanical and chemical irritation of the adjacent tissue. In this case series, seven patients who complained of neurologic complication after overextension of canal filling material during endodontic treatment were presented. Overextensions of filling material into the surrounding tissues, such as the mandibular canal, bone marrow, and submucosal layer, were confirmed with panoramic radiograph and computed tomographic images. When patients complain of neurological disturbances after root canal treatment, proper radiographic images should be taken to verify any overextension of materials and to determine the specific location of the overfilled materials.

Assessment of the cytotoxicity of a mineral trioxide aggregate-based sealer with respect to macrophage activity

AIM

To assess the influence of co-culture with mineral trioxide aggregate (MTA) and MTA Fillapex (FLPX) on the viability, adherence, and phagocytosis activity of peritoneal macrophages from two mouse strains.

METHODOLOGY

Cellular viability, adherence, and phagocytosis of Saccharomyces boulardii were assayed in the presence of capillaries containing MTA and MTA Fillapex. The data were analyzed using parametric (Student's t) and non-parametric (Mann-Whitney) tests.

RESULTS

FLPX was severely cytotoxic and decreased cell viability, adherence, and phagocytic activity of both macrophage subtypes. Cells that were treated with MTA Fillapex remained viable (>80%) for only 4 h after stimulation. Macrophages from C57BL/6 mice presented higher adherence and higher phagocytic activity compared with macrophages from BALB/c mice.

CONCLUSION

Comparison of MTA and FLPX effects upon macrophages indicates that FLPX may impair macrophage activity and viability, while MTA seems to increase phagocytic activity.

Pregabalin in the treatment of inferior alveolar nerve paraesthesia following overfilling of endodontic sealer

A case of orofacial pain and inferior alveolar nerve (IAN) paraesthesia after extrusion of endodontic sealer within the mandibular canal treated with prednisone and pregabalin is described. A 36-year-old woman underwent root canal treatment of the mandibular second right premolar tooth. Post-operative panoramic radiograph revealed the presence of radiopaque canal sealer in the mandibular canal. Damage to IAN consecutive to extrusion of endodontic sealer was diagnosed. Non-surgical management was decided, including: 1 mg/kg/day prednisone 2 times/day, once-daily regimen, and 150 mg/day pregabalin, two doses per day, monitoring the progress with periodic follow-up visits. Six weeks after the incident the signs and symptoms were gone. The complete resolution of paraesthesia and the control of pain achieved suggest that a non-surgical approach, combining prednisone and the GABA analogue pregabalin, is a good option in the management of the IAN damage subsequent to endodontic sealer extrusion. Key words:Endodontics, inferior alveolar nerve, neuropathic pain, orofacial pain, paraesthesia, pregabalin.

Connective tissue reaction of rats to a new zinc-oxide-eugenol endodontic sealer

The aim of this study was to evaluate the biocompatibility in rat subcutaneous connective tissue of a new zinc oxide endodontic sealer (Endomethasone N) compared to those provided by Endofill and Sealer 26. Polyethylene tubes containing the test materials were implanted into dorsal subcutaneous connective tissue of Wistar albino rats. After 7 and 42 days, the implants with the surrounding tissue were collected, fixed, and processed for histologic evaluation. Sections were evaluated for the presence of inflammatory cells (poly or monomorfonuclear), blood vessels, necrosis area, and thickness of fibrous capsule. Comparisons between groups and time-periods were performed with Kruskal-Wallis and Mann-Whitney U non-parametric tests for 5% significance level. No differences in the biocompatibility patterns among the materials for the 2 experimental periods were observed. Independently of the sealer, the tissue behavior showed a tendency to decrease the irritation effect over time. It can be concluded that all sealers are irritant, but its toxicity decreased with time. Endomethásone N showed biocompatible characteristics comparable with those provided by Endofill and Sealer 26.

Long-term cytotoxic effects of contemporary root canal sealers

OBJECTIVES

The aim of the present study was to investigate the effects of root canal sealers on the cytotoxicity of 3T3 fibroblasts during a period of 5 weeks.

MATERIAL AND METHODS

Fibroblasts (3T3, 1×105 cells per well) were incubated with elutes of fresh specimens from eight root canal sealers (AH Plus, Epiphany, Endomethasone N, EndoREZ, MTA Fillapex, Pulp Canal Sealer EWT, RoekoSeal and Sealapex) and with elutes of the same specimens for 5 succeeding weeks after immersing in simulated body fluid. The cytotoxicity of all root canal sealers was determined using the MTT assay. Data were analyzed using ANOVA and Tukey's test.

RESULTS

RoekoSeal was the only sealer that did not show any cytotoxic effects (p<0.05). All the other tested sealers exhibited severe toxicity initially (week 0). MTA Fillapex remained moderately cytotoxic after the end of experimental period. Toxicity of the other tested sealers decreased gradually over time. The evaluated root canal sealers presented varying degrees of cytotoxicity, mainly in fresh mode.

CONCLUSIONS

RoekoSeal had no cytotoxic effect both freshly mixed and in the other tested time points. MTA Fillapex was associated with significantly less cell viability when compared to the other tested root canal sealers.

Systemic pregabalin attenuates sensorimotor responses and medullary glutamate release in inflammatory tooth pain model

Our previous studies have demonstrated that application of inflammatory irritant mustard oil (MO) to the tooth pulp induces medullary glutamate release and central sensitization in the rat medullary dorsal horn (MDH), as well as nociceptive sensorimotor responses in craniofacial muscles in rats. There is recent evidence that anticonvulsant drugs such as pregabalin that influence glutamatergic neurotransmission are effective in several pain states. The aim of this study was to examine whether systemic administration of pregabalin attenuated glutamate release in the medulla as well as these nociceptive effects reflected in increased electromyographic (EMG) activity induced by MO application to the tooth pulp. Male adult rats were anesthetized with isofluorane (1.0-1.2%), and jaw and tongue muscle EMG activities were recorded by needle electrodes inserted bilaterally into masseter and anterior digastric muscles and into the genioglossus muscle, and also the medullary release of glutamate was assessed by in vivo microdialysis. Pregabalin or vehicle control (isotonic saline) was administered 30 min before the pulpal application of MO or vehicle control (mineral oil). Application of mineral oil to the maxillary first molar tooth pulp produced no change in baseline EMG activity and glutamate release. However, application of MO to the pulp significantly increased both the medullary release of glutamate and EMG activity in the jaw and tongue muscles for several minutes. In contrast, pre-medication with pregabalin, but not vehicle control, significantly and dose-dependently attenuated the medullary glutamate release and EMG activity in these muscles after MO application to the tooth pulp (analysis of variance (ANOVA), p<0.05). These results suggest that pregabalin may attenuate the medullary release of glutamate and associated nociceptive sensorimotor responses in this acute inflammatory pulpal pain model, and that it may prove useful for the treatment of orofacial inflammatory pain states.