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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present investigation describes how intradental afferent C-fibers can be identified and characterized in the anaesthetized cat. Functional single fibers innervating the lower canine tooth were recorded from filaments split from the inferior alveolar nerve. Fibers responding to monopolar electrical stimulation of the tooth were classified as slowly and fast conducting according to their conduction velocity (c.v.). The axonal c.v. was determined for 31 slowly conducting fibers by electrical stimulation of the nerve. Sixty-eight percent of these proved to be C-fibers. The slowly conducting fibers had higher activation thresholds, smaller amplitudes and longer durations of the action potentials than the fast conducting fibers. Many of the fast but none of the slowly conducting fibers were repetitively activated by a single stimulus pulse. The highest frequency at which the fibers responded to every stimulus pulse was much lower for the slowly than for the fast conducting fibers. Most of the slowly conducting intradental fibers tested were activated by both hot and cold stimulation of the tooth, by pressure applied to the pulp chamber and by the application of KCl or bradykinin to the pulp. Eight C-fibers responded to mechanical stimulation of the pulp. For some fibers the response magnitude correlated with the stimulus intensity. Many slowly conducting intradental fibers developed an ongoing discharge after heat and pressure stimulation. The results indicate that there exists in the dental pulp of the cat afferent C-fibers that resemble polymodal C-nociceptors. They might be involved in the generation of the dull aching pain present in inflammatory conditions of the pulp. The activation of intradental C-fibers in pulpitis might result either from the elevated pressure and/or by sensitization of the C-fiber endings by inflammatory substances released.
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PMID:Studies on the presence and functional properties of afferent C-fibers in the cat's dental pulp. 150 10

A double-blind pilot study was conducted on 27 consenting human volunteers who had irreversible pulpitis associated with persistent toothache pain from open carious lesions. Formulations tested contained either 0, 10%, or 20% benzocaine and were identified only by a numbered code. Before the experiment started, a small amount of a known 5% benzocaine gel was placed for 1 minute on the tongue of each patient to assure a sensation of numbness within the oral cavity. Then the test tooth was washed with a gentle stream of warm water and dried with gauze. A randomly selected test medication was placed into the open cavity and around the gingival margins for 5 minutes. Pre- and posttreatment tests were conducted at the following timed intervals: 0, 5, 15, 30, 45, 60, 75 and 90 minutes. The tests included degree of pain (rated: 0 = none, 1 = mild, 2 = moderate, 3 = severe); electrical pulp testing (EPT) by a modified, voltage-ramping instrument; and ice water testing (0.5 mL directed quickly onto sound enamel of the tooth and rated: 0 to 4, with 4 being intolerable). After testing, or when pain returned to baseline, endodontic procedures were performed. There was a significant increase (p < 0.032, Fisher exact test) in subjects obtaining pain relief, rated by verbal descriptors, from the benzocaine gels (14 out of 18 improved) compared to placebo (3 out of 9 improved). It was concluded that: 1) benzocaine gels are effective formulations for temporary relief of toothache pain, 2) there were no statistical differences in EPT scores between teeth having pulpitis and control teeth, 3) there were no correlations between direction of EPT scores and pain relief, 4) cold water testing was a good predictor of whether or not a tooth had pulpitis, and 5) changes in cold water testing scores after treatment could not be correlated to relief of pain according to verbal descriptors. The effectiveness of benzocaine in relieving toothache pain verifies previous studies; however, a difference between 10% and 20% benzocaine could not be demonstrated probably because of two factors: 1) the present experiment had a small sample size, and 2) there was no direct measurement of duration of local anesthesia.
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PMID:Use of verbal descriptors, thermal scores and electrical pulp testing as predictors of tooth pain before and after application of benzocaine gels into cavities of teeth with pulpitis. 249 60

Two case reports are presented to illustrate the effectiveness of cold in localizing the offending tooth in difficult diagnostic situations where painful pulpitis is present. A review of the literature reveals that there are several proposed theories concerning the mechanisms by which cold relieves the painful symptoms present in some cases of irreversible pulpitis. The hydrodynamic theory seems to provide the most feasible explanation of the events that occur.
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PMID:Cold as a diagnostic aid in cases of irreversible pulpitis. Report of two cases. 658 63

The sensory nerve fibres in the pulp consist of myelinated A- and unmyelinated C-fibres which conduct nerve impulses. The A-fibres are larger in diameter and fast conducting. Most of the A-fibres are in the A-delta group, but also the existence of very fast A-beta fibres has been demonstrated. C-fibres are small and slow conducting. When natural stimuli such as heat, cold, drilling or drying of dentine with air blasts are applied on the tooth, the only sensation perceived seems to be that of pain. On the other hand perception of pain symptoms in clinical situations varies from sharp and piercing to dull and poorly localised. A- but not C-fibres respond to dentine stimulation, and therefore responsible for dentine sensitivity. When heat is applied to the tooth, there is a two-phase response. First there is an immediate A-fibre response followed by a C-fibre response. The A-fibres could be responsible for the sharp well localised pain in human subjects while C-fibres could be responsible for the dull pain radiating to other parts of the face. A-fibres are activated at a higher level of electrical stimulation than C-fibres. C-fibres, but not A-fibres respond to application of bradykinin and histamin. The functional differences in A- and C-fibres may be one explanation for the change in the pain symptoms which at the beginning of pulpitis are mediated by A-fibres and in advanced pulpitis by C-fibres.
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PMID:Comparison of functional characteristics of intradental A- and C-nerve fibres in dental pain. 869 25

The correlation between the histopathologic examination of pulp biopsy specimens and patients' complaints and signs was investigated. The sensitivity, specificity and reliability of each complaint and sign, and the characteristics of pain that are associated with treatable and untreatable pulp states is proposed. Pulp specimens were obtained from teeth that required endodontic treatment. Clinical data were recorded to identify each patient's complaints. The pulp specimens were processed and the histopathologic diagnoses were categorised and correlated with the patients' complaints. Of the 240 cases, 100 (41.7%) were diagnosed as atrophic pulp or pulposis; 4 (1.7%) as acute pulpitis; 64 (26.7%) as transitional stage; 56 (23.3%) as chronic pulpitis, and 16 (6.7%) as acute pulpitis superimposed on a chronic pulpitis. Results showed that previous pain (p < 0.05), spontaneous pain (p < 0.01), and prolonged pain on cold stimuli (p < 0.05), were significantly more frequent in the patients with chronic pulpitis compared to those with pulposis or transitional stage. We concluded that clinicians must consider the sensitivity and specificity of patient complaints and signs in order to perform a diagnosis based upon clinical evidence.
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PMID:Relationship of patient complaints and signs to histopathologic diagnosis of pulpal condition. 1588 30

Every practice has patients who complain of cold sensitivity and pain on biting while showing no obvious signs of irreversible pulpitis. After loading each cusp and fossa in a symptomatic quadrant and ruling out pulp and periodontal pathology, definitive treatment can be performed to alleviate the patient's symptoms in a consistent, conservative manner using esthetic computer-aided design/computer-aided manufacturing porcelain restorations. Single-appointment definitive restorations can be advantageous for the patient because of the elimination of many steps involved in laboratory fabrication of porcelain or metal restorations.
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PMID:Efficient, conservative treatment of symptomatic cracked teeth. 1649 96

This study compared preoperative administration of acetaminophen or a combination of acetaminophen and ibuprofen versus placebo for potential increased effectiveness of inferior alveolar nerve (IAN) block anesthesia. There were 40 patients with irreversible pulpitis randomly assigned to a drug or placebo group. Thirty minutes after ingestion of medication, an IAN block was administered. A cold test was done 15 minutes after the block, and if the patients had no sensitivity, endodontic therapy was initiated. If the patient had no pain on access, the IAN was recorded as successful. If the patient had sensitivity to cold or to the access procedure, it was recorded as a failure. Overall success was 60% for all three groups. Success was 71.4% for the acetaminophen group, 75.9% for the acetaminophen and ibuprofen group, and 46.2% for the placebo group. There was no significant difference between the groups; however, there was a trend toward higher success in the medication groups.
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PMID:The effect of preoperative acetaminophen or a combination of acetaminophen and Ibuprofen on the success of inferior alveolar nerve block for teeth with irreversible pulpitis. 1718 19

Cracked and broken teeth present a diagnostic dilemma to the dentist and the sooner a correct diagnosis is made the greater are the chances to save the tooth. As the location, direction and size of the crack or fracture dictates the choice of treatment, it is important to first define the types of cracks and fractures in the coronal and radicular tooth structure. Cracks and fractures can be classified as follows: 1. craze lines 2. fractured cusps 3. cracked teeth 4. split teeth 5. vertical root fractures. The vertical root fracture has been described recently in two articles in this publication, and therefore will not be discussed here. Diagnosis of a cracked tooth is not always initially obvious. The patient's response to clinical testing is the primary diagnostic tool along with the dental history provided by the patient. Radiographs are secondary in making a diagnosis. Clinical aids for reproducing the patient's symptoms such as occlusal bite devices, observing occlusal wear facets and the application of cold water to one tooth at a time may isolate the offending tooth. In situations where an irreversible pulpitis is diagnosed, endodontic treatment is indicated. In the case of a questionable diagnosis, or one in which a potential reversible pulpitis is made, a provisional restoration can be placed for an unspecified time as a diagnostic aid. If endodontic therapy were indicated, consultation with the patient as to the compromised prognosis and the alternatives to endodontic treatment is essential.
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PMID:Cracked and broken teeth--definitions, differential diagnosis and treatment. 1769 60

Pulpitis pain might be triggered by a cold stimulus, yet the cellular mechanisms responsible for this phenomenon are largely unknown. One possible mechanism involves the direct activation of cold-responsive thermoreceptors. The purpose of this study was to evaluate the possible role of the TRPM8 thermoreceptor in cold-mediated noxious pulpal pain mechanisms by comparing expression patterns in pulpal nerves from healthy control molars to cold-sensitive painful molars with irreversible pulpitis. Samples were identically processed with the indirect immunofluorescence method, and images were obtained with confocal microscopy. The immunofluorescence intensity and area occupied by TRPM8 within N52/PGP9.5-identified nerve fibers were quantified. Results showed that relative to normal samples, TRPM8 nerve area expression was significantly less in the cold-sensitive painful samples (34.9% vs 8%, P <0.03), but with no significant difference in immunofluorescence intensity between the 2 groups. These results suggest that TRPM8 is most likely not involved in cold-mediated noxious pulpal pain mechanisms.
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PMID:TRPM8 Axonal expression is decreased in painful human teeth with irreversible pulpitis and cold hyperalgesia. 1788 83

Irreversible pulpitis has been associated with pain and an increase in the number of pulp inflammatory cells. Based on the action of nitric oxide (NO) elsewhere, NO may possibly participate in the sensory and autonomic innervation of the dental pulp, and may influence local inflammatory responses. The purpose of this study was to analyze normal and inflamed human dental pulp for the presence of NADPH-diaphorase (NADPH-d), as an index of NO system activity. Six non-carious second premolar pulp tissue samples were obtained from young patients who required extractions for orthodontic reasons and six inflamed samples were obtained from symptomatic carious second premolars clinically diagnosed with irreversible pulpitis. Pulp tissue was carefully removed, fixed by immersion in a cold 4% PFA buffered solution for 120 min, rinsed in cold phosphate buffer, and quickly-frozen for cryostat sectioning. Pulp tissue was sectioned perpendicularly to the vertical axis of the tooth at 20 microm and processed for histochemistry. Sections of each specimen were stained with hematoxylin-eosin and other sections were subjected to histochemical NADPH-d detection. Results indicated the presence of NADPH reactivity within the pulps of both normal and carious teeth. In the normal teeth NADPH-d activity was detected in a small number of vascular endothelial cells and fibroblasts. The inflammatory response of the pulp from carious premolars was detected in connective tissue by the presence of an increased number of fibroblasts, angioblasts and collagen fibers. It was possible to determine the extent of odontoblast reactivity since the odontoblast layer was usually absent in these split-peel preparations. There were no obvious signs of stained pulpal nerve fibers. Overall NADPH-d staining was significantly more intense within inflamed pulp tissues compared to normal healthy samples (Mann-Whitney test, p<0.002). These results suggest that NADPH-d may be used as a marker of inflammatory activity in pulpitis and provide the basis for further studies aiming to clarify the possible functions of NO in human dental pulp in pathophysiological situations.
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PMID:Action of nitric oxide on healthy and inflamed human dental pulp tissue. 1833 11


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