Electric pulp testing: a review

Electric pulp testing (EPT) has been available for more than a century and used in dental practices worldwide. This article provides an overview of this diagnostic aid. The PubMed database from 1953 was used initially; the reference list for pulp testing featured 1071 articles, and for EPT identified 121 papers. A forward search was undertaken on these articles and using selected author names. Potentially relevant material was also sought in contemporary endodontic texts, while older textbooks on endodontics, operative dentistry and pain revealed historic information and primary research not found electronically. A short account of the innervation of the pulp is followed by an historic overview. Clinical considerations discussed include tooth isolation, glove wearing and tester electrode placement. Orthodontic treatment, pacemaker wearing and patient medications are considered. Research applications are also discussed. While EPT is valuable, no single pulp testing technique can reliably diagnose all pulp conditions. Careful collection of patient history regarding the problem tooth and prudent use of appropriate radiographs are also helpful. The shortcomings of electric tests, especially in the case of immature and concussed teeth, must be understood. The demeanour of the patient and the responses given by control teeth also require careful consideration.     

牙髓炎急性发作时牙髓活力温度测验结果与牙髓组织活力的关系研究

目的　评价不同阶段牙髓炎急性发作的患牙牙髓活力温度测验结果差异性，观察牙髓炎急性发作时牙髓活力温度测验结果与牙髓组织活力的关系。方法　选择2015年7月至2016年3月于首都医科大学附属北京口腔医院急诊综合诊疗中心就诊的以牙髓炎急性疼痛为主诉的患者94例，根据牙髓活力温度测验结果将患牙分为激发痛组、迟钝组、正常组、热痛冷缓解组和无反应组等5组，通过临床观察法（开髓法）观察牙髓炎症组织活力。比较不同牙髓活力温度测验结果患牙的临床诊断类型的差异，以及不同测验结果患牙之间的牙髓组织活力的差异。结果　5组不同牙髓活力温度测验结果患牙的临床诊断类型的差异具有统计学意义（P < 0.05）。5组不同牙髓活力温度测验结果患牙之间比较，冠髓组织活力差异具有统计学意义（P < 0.05），而根髓组织活力差异无统计学意义（P = 0.331）。牙髓活力温度测验推测冠髓组织活力的准确率为78.6%。 结论　不同阶段牙髓炎急性发作时患牙牙髓活力温度测验结果存在差异。牙髓炎急性发作时，牙髓活力温度测验结果不同说明冠髓组织活力不同。牙髓活力温度测验可在一定程度上帮助推测牙髓组织活力状态。     

电子麻醉对牙髓SP、CGRP阳性纤维的作用

目的：研究电子麻醉镇痛作用的外周机理。方法：用免疫组化方法观察电子麻醉对大鼠牙髓及牙周组织感觉神经肽的影响。结果：电活力测试仪刺激可使被测牙牙髓内SP、CGRP阳性纤维完全脱失,牙周组织及领域牙不受影响。而电子麻醉使被累及的牙齿牙髓中的SP、CGRP阳性纤维数量减少,刺激部位牙龈组织中的SP、CGRP阳性纤维脱失。结论：电活力测试仪刺激仅兴奋牙髓中的感觉神经纤维,而电子麻醉可同时兴奋牙周组织及牙髓中的感觉神经纤维。电子麻醉和电活力测试仪刺激所兴奋的神经纤维可能属于不同的功能亚群,它们的兴奋分别产生镇痛作用的疼痛。     

Assessment of pulp vitality: a review

Background.  One of the greatest diagnostic challenges in clinical practice is the accurate assessment of pulp status. This may be further complicated in paediatric dentistry where the practitioner is faced with a developing dentition, traumatized teeth, or young children who have a limited ability to recall a pain history for the tooth in question. A variety of pulp testing approaches exist, and there may be confusion as to their validity or appropriateness in different clinical situations.
Aim.  The aim of this paper is to provide the clinician with a comprehensive review of current pulp testing methods. A key objective is to highlight the difference between sensitivity testing and vitality testing. A biological basis for pulp testing is also provided to allow greater insight into the interpretation of pulp testing results. The rationale for, and methods of, assessing pulpal blood flow are described.     

Vital pulp therapy of mature permanent teeth with irreversible pulpitis from the perspective of pulp biology

The American Association of Endodontists (AAE) Consensus Conference Recommended Diagnostic Terminology states that mature permanent teeth clinically diagnosed with irreversible pulpitis are treated with pulpectomy and root canal filling because inflamed vital pulp is not capable of healing. Histological studies have demonstrated that clinically diagnosed irreversible pulpitis does not involve the entire pulp. A recent International Endodontic Journal Editorial suggested clinical diagnosis of pulp disease should be reassessed because of the poor correlation between clinical symptoms and pulp sensibility testing and the actual histological status of the pulp. This review identified studies in a PubMed search that provide evidence for vital pulp therapy (VPT) of mature permanent teeth with irreversible pulpitis is predictable if correctly diagnosed and properly treated. A narrative review was undertaken to outline the correlation between the clinical symptoms/signs and pulp sensibility testing and the histological findings of the pulp. Treatment procedures for permanent teeth are outlined.     

Pulp size in molars: underestimation on radiographs

The aim was to determine whether radiographs provide a clinically useful indication of pulp size in diseased/restored human first molar teeth, and to investigate accessibility of pulp tissue for diagnostic testing using laser Doppler flowmetry (LDF). Extracted teeth of known age were collected. Restorative materials were removed and teeth with evidence of pulp exposures excluded. Fifty-six teeth were radiographed from buccal and mesial aspects, and then their crowns were sectioned axiobuccolingually and photographed. Images were digitally scanned and measurements made of the total pulp area (above a line across the most superior part of the pulpal floor) and the pulp area in the clinical crown (superior to a line between the amelocemental junctions). The pulp width at the cervix and the highest point of the pulp were also recorded. Data were analysed using Pearson correlations. Pulp areas within the clinical crowns were significantly larger than indicated by radiographs, by 23% in the case of the clinically attainable buccal view (P < 0.05). Pulps may be more accessible to flowmeter testing than they appear. Absence of pulp tissues in the crown was recorded in equal numbers of teeth on radiographs and sections, but with agreement for only one tooth. Sixteen per cent of the teeth had no pulp area in the clinical crown when sectioned, but might still be suitable for testing using LDF.     

恒牙牙髓炎的活髓保存治疗

活髓保存治疗是尽最大限度保留健康牙髓组织、提高患牙远期保存率的方法,但其被认为适应范围有限,疗效不确定。牙髓组织的病理学改变是决定临床治疗方案和评估疗效的组织学基础,而常用的检查方法无法全面反映牙髓的病理学改变。随着对牙髓生物学研究的深入、现代诊疗技术及盖髓材料的革新,活髓保存治疗越来越多地被应用在以往被认为需要摘除牙髓的患牙上。本文根据循证文献,就牙髓炎病理改变、恒牙牙髓炎活髓保存治疗的临床研究等方面进行分析讨论和总结。在活髓保存治疗的过程中综合运用包括激光多普勒血流仪、组织氧检测仪、核磁共振成像、牙科显微镜等技术与方法准确判断牙髓炎症状态,并依此决定牙髓的去留程度;结合严格的感染控制与高生物相容性盖髓材料的使用,活髓保存治疗可运用在部分龋源性露髓患牙与出现不可复性牙髓炎症状的恒牙上。未来的研究则需从牙髓修复再生机制、牙髓炎诊断精准化、盖髓材料的升级等方面提高恒牙牙髓炎活髓保存治疗的成功率。     

Diagnostic pulp testing in dentistry: how far have we come?

Techniques of pulp testing to determine vitality or sensibility have been in use for decades. While very little has changed in our methodologies, our understanding of the biology of the health and disease of the dental pulp has been enhanced. However, without thorough data collection using appropriate tests, and an integrated synthesis and analysis of this data, there is little chance of arriving at a diagnosis that will determine the proper course of treatment. While this need was clearly identified by Dr. Truman W Brophy over 130 years ago, we are still faced with these challenges today.     

三种方法对受创牙进行牙髓活力测试结果的比较

目的：用三种不同方法对近期外伤前牙进行牙髓活力测试,比较其准确性。方法：选择2008～2011年在解放军81医院口腔科就诊的64例上前牙创伤的82颗患牙,分别用冷测、电活力测试、血氧饱和度测试其牙髓活力,并于4、7、14、21、28d、2、3、6月进行复查,与前期结果进行比较分析。结果：0～28d,所有受试牙对冷测及电测均无反应。28d～6月,受试牙对冷测呈阳性反应由31颗上升至75颗,电测组为29颗上升至73颗。0d-6月,血氧饱和度值正常的受试牙数保持不变,为77颗。结论：血氧饱和度测试法对外伤牙的牙髓活力判断准确、可靠。     

Analysis and comparison of pulp vitality after total and segmental LeFort I osteotomy

A more systematic electrical testing of pulp vitality demonstrated that the recovery rate of pulp vitality was 89.5% after 12 months of total and segmental LeFort I osteotomy. Segmental LeFort I osteotomy only imposed an interference to the speed of pulp vitality recovery. In other words, the recovery rate of pulp vitality in segmental LeFort I osteotomy was comparable to that in total LeFort I osteotomy. Maxillary segmentation inflicted a minimum damage to its adjacent teeth if clinical manipulation was meticulous and skillful. Interdental osteotomy did not exert an apparent effect on the recovery of pulp vitality and the positive rate of pulp vitality in the teeth close to it was roughly similar with that of homonymous teeth on the opposite side or their adjacent teeth on the same side.     

Pulse oximetry evaluation of vitality in primary and immature permanent teeth

Present methods of assessing pulp vitality (electric and thermal testing) are of limited use with children, often resulting in false positive or false negative results. Pulse oximetry is a proven, atraumatic method of measuring vascular health by evaluating oxygen saturation (SaO2). This pilot study explores the use of a modified pulse oximetry ear probe to assess pulpal vascular oxygen saturation in primary and immature permanent teeth. Pulse oximetry readily differentiated between known vital and nonvital teeth. Vital teeth consistently provided SaO2 values that were lower than the values recorded on the patients' fingers. Further study of the SaO2 changes in traumatized teeth, with a probe designed specifically for teeth, is warranted by these initial results. Although additional research is indicated, pulse oximetry is already an objective, atraumatic clinical alternative to the present electrical and thermal methods of assessing pulp vitality in children's teeth.     

Cultured pulp fibroblasts: are they suitable for in vitro cytotoxicity testing?

The use of cell cultures to test the biocompatibility of dental materials is gaining in importance. Any cytotoxic effects that restorative materials may have will be on the dental pulp and for that reason cultured pulp cells should be the model of choice for biocompatibility testing. The aim of this investigation was to study the growth and morphologic characteristics and toxic response of human pulp lines and to compare these parameters to those of human buccal mucosa fibroblasts. Twenty-one specimens of pulp tissue and six from buccal mucosa were cultured using standard techniques. Six pulp cell lines were cultured successfully as were all six from the buccal mucosa specimens. From these specimens, 12 growth curves were computed. To study the morphology of the cultured cells, they were observed microscopically and classified into three morphological types: slender elongated cells (type I), epithelioid shaped cells (type II) and large stellate cells (type III). Their numbers and proportions were determined for each cell line and compared statistically. To gauge sensitivity to toxic materials, cells were exposed to concentrations of arecoline. An analysis of the growth curves showed no statistical difference between pulp cells and buccal mucosa cells; the slopes of the curves, however, differed significantly between individual cell lines, and these individual differences were greater among pulp cell lines. The morphology of the pulp and mucosa fibroblasts was similar microscopically. There was no significant difference between the number and proportion of the cell types in the two groups, but there were significant differences between the individual cell lines. Pulp cells showed a greater inhibition of growth when exposed to arecoline. Because pulp fibroblasts are difficult to culture, their reported survival rate is poor; due to the differences that exist between individual cell lines, we conclude that pulp cells when used as single cell lines or even pooled may not be ideal for testing biocompatibility, especially if reproducibility is a prerequisite. Any evaluation will require tests on not one, but several cell lines in order to minimize the effect of inter-cell-line differences. Their greater sensitivity to toxic substances, on the other hand, may show that pulp cells could be more sensitive indicators of cytotoxicity.     

Rationalization of electric pulp-testing methods.

A new electric pulp-testing system, the Testark, was developed in order to assess the potential of a different way of testing pulp sensitivity, thus making this electric pulp test more dependable than the conventional electric pulp-testing method. A study was conducted to evaluate the potential of the Testark system in comparison with a commercially available pulp tester. This pilot study consisted of application of three different desensitizing agents (sodium fluoride, test product. 'A', and test product 'B') to the cervical areas of hypersensitive teeth. The results were recorded with both the Testark and the conventional pulp tester simultaneously, and the sodium fluoride and test product 'B' proved to yield a beneficial effect by desensitizing the teeth after a single application. The level of desensitization with these agents was higher than the level obtained with the test product 'A' paste, which was utilized daily for 14 days. The results obtained with the conventional pulp tester differed by way of interpretation from those obtained with the Testark system. The Testark system proved to be easy to use and highly accurate in the data readings because of its high resolution. The Testark systemwas found to be more dependable than the commerical pulp tester, since it reduced the subjective errors which are inevitable when a commerical pulp tester is used. The Testark system is being developed further, and more studies are being conducted at the present time, in order to assess the full potential of the instrument.     

Comparison of electrical, thermal, and pulse oximetry methods for assessing pulp vitality in recently traumatized teeth

Pulse oximeter is a well-established and noninvasive method for measuring vascular health by evaluating oxygen saturation. This study compared the efficacy of a custom-made pulse oximeter dental probe with the electric pulp testing and thermal testing for measuring pulp vitality status of recently traumatized permanent teeth. Readings for pulp vitality for 17 recently traumatized maxillary incisors were taken with custom-made pulse oximeter dental probe (group 1), electrical pulp tester (group 2), and thermal testing (group 3) over a 6-month period. The proportion of recently traumatized teeth showing a positive responsiveness in thermal/electric pulp tests increased from no teeth showing responsiveness on day 0 to 29.4% teeth on the 28th day, 82.35% of teeth at 2 months, and 94.11% teeth at 3 months. However, pulse oximeter gave positive vitality readings that remained constant over the study period from day 0 to 6 months in all patients.     

Assessment of Oxygen Saturation in Dental Pulp of Permanent Teeth with Periodontal Disease

Introduction

In individuals with periodontal disease, dental pulp status should be determined before a treatment plan is made. Pulse oximeters are promising diagnostic tools to evaluate pulp vascularization. This study used pulse oximetry to determine the level of oxygen saturation in dental pulp of intact permanent teeth with periodontal attachment loss (PAL) and gingival recession (GR) and to evaluate the correlation between periodontal disease and level of oxygen saturation in the pulp.

Methods

This study included 67 anterior teeth of 35 patients; all teeth showed intact crowns, PAL, a periodontal pocket (PP), and GR. The teeth underwent periodontal examination, cold and electric pulp testing, and pulse oximetry measurements. The Pearson correlation coefficient and a linear regression coefficient were calculated to evaluate the degree of correlation between periodontal disease markers (PAL, PP, and GR) and the level of oxygen saturation in dental pulp. These tests also evaluated possible associations between oxygen saturation and cold and electric pulp testing.

Results

PAL, PP, and GR had negative correlations with oxygen saturation in dental pulp. Conversely, no statistically significant association was found between oxygen saturation in dental pulp and the response to electric sensibility testing.

Conclusions

Oxygen saturation was lower in the pulp of permanent teeth with PAL, PP, and GR, indicating that periodontal disease correlates with the level of oxygen saturation in the pulp.     

右侧下颌第一磨牙近中原发性牙根纵裂行活髓保存治疗1例

本文报告1例右侧下颌第一磨牙原发性牙根纵裂的发现与诊治过程。通过临床检查、多普勒血流仪及影像学等辅助检查,发现该患牙牙髓电测试有反应,激光多普勒测试有血运。本病例采用显微根尖手术方法以及纳米生物活性材料进行治疗,术后随访1年效果良好,实现了对该患牙折裂部分的去除及感染控制,以活髓状态保存患牙。     

右侧下颌第一磨牙近中原发性牙根纵裂行 活髓保存治疗1例

本文报告1例右侧下颌第一磨牙原发性牙根纵裂的发现与诊治过程。通过临床检查、多普勒血流仪及影像学等辅助检查,发现该患牙牙髓电测试有反应,激光多普勒测试有血运。本病例采用显微根尖手术方法以及纳米生物活性材料进行治疗,术后随访1年效果良好,实现了对该患牙折裂部分的去除及感染控制,以活髓状态保存患牙。     

年轻恒牙活髓保存治疗

年轻恒牙活髓保存的目的是为了保护冠部或根部剩余牙髓组织的活性和功能,促进牙根生理性发育。传统观点认为,活髓保存只适用于牙髓正常或可逆性牙髓炎、无根尖病变的患牙,以保留患牙剩余未被感染的健康牙髓组织。但迄今为止,并没有可靠的手段能准确判断牙髓状态。此外,多个研究显示龋源性露髓、伴有不可逆性牙髓炎及根尖周感染的患牙活髓保存治疗成功。临床上应充分利用年轻恒牙牙髓组织再生修复能力强的组织学特点,对年轻恒牙牙髓治疗采取更为保守的方法,以期获得更好的预后。     

Pulpal response to a zinc oxide–eugenol cement

Summary. The British Standards Institution have produced a recommended testing procedure for toxicity of dental materials; this advocates the use of a zinc oxide—eugenol cement such as Kalzinol, as a bland control in deep cavities. In this study, Kalzinol was applied directly to the exposed pulps of germ-free rat molar teeth. This resulted in pulpal inflammation in contact with the material; when dentine particles separated Kalzinol from the pulp, calcific repair tissue was observed without inflammation or necrosis. Further investigation is required into suitable control materials for use in toxicity testing of restorative and lining materials.     

Pulp sensibility and vitality tests for diagnosing pulpal health in permanent teeth: a critical review

The aim of this review was to critically appraise the literature related to pulp vitality and sensibility testing in order to determine the diagnostic accuracy of pulp tests with reference to a gold standard or control group. Implications of the results for research and clinical practice are also explored. The MEDLINE (Ovid), MEDLINE (PubMed), Embase and Cochrane databases were searched for English‐language clinical trials in humans in which in vivo studies were designed to evaluate or compare the accuracy of selected pulp sensibility and pulp vitality tests in determining the state of pulpal health in permanent teeth. Studies were included only if the results were compared to a control group or to a valid gold or reference standard. Eight studies were identified. Shortcomings in research design were found to influence the findings. The limited number of studies investigating pulp vitality tests was insufficient to answer the research question. It was concluded from this critical appraisal of the literature that laser Doppler flowmetry appeared to be the most accurate method for diagnosing the state of pulpal health and came closest to serving as a gold standard. Pulp vitality tests proved superior to pulp sensibility tests for early and accurate assessments of the pulpal health of traumatized teeth. When accurately used and interpreted, pulp sensibility tests provide valuable diagnostic information, particularly when an electric pulp test is used in combination with either CO₂ snow or Endo‐Ice.