The incidence of mechanical allodynia in patients with irreversible pulpitis.

The mechanisms of odontogenic pain are complex and incompletely understood. Cases of irreversible pulpitis are thought to represent a localized inflammatory response to bacterial challenge in dental pulp tissue. The presenting symptoms are classically defined by exaggerated painful episodes to thermal stimuli that may linger after cessation of the stimulus. However, the associated incidence of mechanical allodynia, defined as reduced mechanical pain threshold to masticatory forces, has not been characterized. This study evaluated pain intensity ratings and the presence of mechanical allodynia reported by 993 consecutive dental patients presenting for tooth extraction in a community health center. After clinical and radiographic examinations, the pulpal/periradicular diagnostic categories were normal pulp/normal periradicular (n=792 patients), irreversible pulpitis/normal periradicular (n=86), or irreversible pulpitis/acute periradicular periodontitis (n=115). The rank order for the mean values of pain intensity ratings was irreversible pulpitis/acute periradicular periodontitis > irreversible pulpitis/normal periradicular > normal/normal (p<0.05 for all comparisons). The incidence of mechanical allodynia in patients presenting with irreversible pulpitis was 57.2%, indicating that periradicular mechanical allodynia contributes to early stages of odontogenic pain because of inflammation of vital pulpal tissue.

Measurement of mechanical allodynia and local anesthetic efficacy in patients with irreversible pulpitis and acute periradicular periodontitis.

An essential feature of symptomatic periradicular inflammation is mechanical allodynia, defined as reduced mechanical pain thresholds. A previous study evaluating a new digital force transducer showed that it reliably measures mechanical pain thresholds of teeth with normal periradicular tissues. In this study, we tested the hypothesis that the force transducer quantitatively measures mechanical allodynia in teeth with acute periradicular periodontitis (APP) and detects the effects of local anesthetic injection. Mechanical pain thresholds were measured in patients (n = 30) with irreversible pulpitis (IP) and APP and compared with their contralateral teeth. The results show that the mechanical pain thresholds of teeth with IP and APP were reduced by 77% compared with contralateral control teeth. The administration of local anesthesia reversed the mechanical allodynia by 62%, and significant sex-specific effects were observed. In addition, the normal teeth contralateral to the symptomatic teeth had lower mechanical thresholds than those observed in healthy volunteers, suggesting that central sensitization occurs during this type of odontalgia. Thus, we show that the mechanical pain thresholds are significantly reduced in teeth with IP and APP and that the force transducer has potential application as a diagnostic aid in measuring mechanical allodynia and as an outcome measure in endodontic clinical trials such as pharmacologic studies and mechanistic research.

The development of a diagnostic instrument for the measurement of mechanical allodynia.

Mechanical allodynia, defined as a reduction in mechanical pain threshold, is an essential diagnostic feature of inflammation of the periodontal ligament. Traditional methods for measuring mechanical allodynia in a tooth are not quantitative. This study evaluated the reliability of a new bite force transducer to measure mechanical pain thresholds, which might have application as a quantitative diagnostic aid for measuring mechanical allodynia in patients with apical periodontitis. To determine inter-observer reliability, subjects (n = 40) were given standardized instructions before generating maximal bite force on maxillary first molars; readings were then recorded by three examiners for a total of ten readings per examiner. To determine the test-retest reliability, the initial examiner then retested at two different sessions. The intraclass correlation coefficient was fair to substantial for inter-observer reliability (0.3-0.64) and substantial for intra-observer reliability (0.63-0.68). Thus, the force transducer used in our study is a reliable method to measure mechanical pain thresholds in endodontic patients.

Development of new pain management strategies.

The continued development of more effective and predictable methods for pain control is a process that combines the best efforts of basic and clinical scientists. This review explores the developing themes of clinical pain management strategies that are emerging from molecular, cellular, and physiologic research into pain mechanisms and emphasizes the unique opportunity that several years of well-controlled clinical trials affords the dental education community to provide evidence-based learning in pain treatment strategies.

A multimedia patient simulation for teaching and assessing endodontic diagnosis.

Teaching and assessing diagnostic skills are difficult due to relatively small numbers of total clinical experiences and a shortage of clinical faculty. Patient simulations could help teach and assess diagnosis by displaying a well-defined diagnostic task, then providing informative feedback and opportunities for repetition and correction of errors. This report describes the development and initial evaluation of SimEndo I, a multimedia patient simulation program that could be used for teaching or assessing endodontic diagnosis. Students interact with a graphical interface that has four pull-down menus and related submenus. In response to student requests, the program presents patient information. Scoring is based on diagnosis of each case by endodontists. Pilot testing with seventy-four junior dental students identified numerous needed improvements to the user interface program. A multi-school field test of the interface program using three patient cases addressed three research questions: 1) How did the field test students evaluate SimEndo I? Overall mean evaluation was 8.1 on a 0 to 10 scale; 2) How many cases are needed to generate a reproducible diagnostic proficiency score for an individual student using the Rimoldi scoring procedure? Mean diagnostic proficiency scores by case ranged from .27 to .40 on a 0 to 1 scale; five cases would produce a score with a 0.80 reliability coefficient; and 3) Did students accurately diagnose each case? Mean correct diagnosis scores by case ranged from .54 to .78 on a 0 to 1 scale. We conclude that multimedia patient simulations offer a promising alternative for teaching and assessing student diagnostic skills.

New advances in the management of endodontic pain emergencies.

The development of more effective strategies for managing endodontic pain emergencies draws from the research of both clinicians and basic scientists. This review explores evidence-based approaches for managing endodontic pain emergencies and newly emerging pain management strategies based upon molecular, cellular and physiologic research into pain mechanisms.

Strategies for managing the endodontic pain patient.

The most common form of orofacial pain is odontalgia, or toothache. This painful condition afflicts about 12-14 percent of the population, or about 2.5 million Texans (1-4). This is an important clinical challenge since our patients have high expectations for receiving the latest advances in health care, and successful pain control in endodontics is no exception. Fortunately, research has provided new approaches for delivering more effective pain control treatments in an efficient and reproducible manner. This article provides an overview of several treatment strategies for managing acute odontogenic pain; due to space limitations, interested readers are encouraged to use the references for more extensive discussions on these topics.