Efficacy of four local anaesthesia protocols for mandibular first molars with symptomatic irreversible pulpitis: A randomized clinical trial.

AIM: To examine the efficacy rate of four anaesthetic protocols in mandibular first molars with symptomatic irreversible pulpitis (SIP). METHODOLOGY: One hundred and sixty patients with a diagnosis of SIP were included in this randomized clinical trial. Patients were randomly allocated into four treatment groups (N = 40) according to the administered technique: Group 1 (IANB): standard inferior alveolar nerve block (IANB) injection; Group 2 (IANB + IO): standard IANB followed by a supplemental intraosseous infusion (IO) injection; Group 3 (IANB + PDL): standard IANB followed by a supplemental periodontal ligament (PDL) injection; Group 4 (IANB + BI): standard IANB followed by a supplemental buccal infiltration. Patients rated pain intensity using a verbal rating scale when the root canal treatment procedure was initiated, that is, during caries removal, access preparation and pulpectomy. Heart rate changes were recorded before, during and after each injection. The anaesthetic efficacy rates were analysed using chi-square tests, age differences using one-way anova, gender differences using Fischer Exact tests whilst heart rate changes were analysed using Kruskal-Wallis tests. Statistical significances were set at p < .05 level. RESULTS: All the included patients were analysed. No differences in the efficacy rate were found in relation to the age or gender of the participants amongst the study groups (p > .05). IANB + IO injections had a significantly higher efficacy rate (92.5%) when compared to other techniques (p < .05), followed by IANB + PDL injections (72.5%), IANB + BI injections (65.0%), with no significant differences between the IANB + PDL or IANB + BI injections (p > .05). IANB injection alone had a significantly lower rate (40%) compared to the other techniques (p < .05). A transient but significant rise in the heart rate was recorded in 60% (24/40) of patients who received the IANB + IO injection compared to other groups (p < .05). CONCLUSIONS: Inferior alveolar nerve block injection alone did not reliably permit pain-free treatment for mandibular molars with SIP. The use of an additional IO supplemental injection provided the most effective anaesthesia for patients requiring emergency root canal treatment for SIP in mandibular posterior teeth.

Descripción de las propiedades funcionales del sistema nociceptivo trigeminal en relación con el dolor pulpar / Description of the functional properties of the nociceptive trigeminal system in relation to pulpal pain

El sistema trigeminal nociceptivo es un componente del sistema sensorial somestésico que tiene la capacidad de discriminar cuatro variables básicas de los estímulos que provocan daño tisular, ellas son: cualidad, curso temporal, localización e intensidad. Las fibras A delta y C, vinculadas a la nocicepción están presentes en la pulpa dental. Se utilizan varias clasificaciones del dolor, atendiendo a diversos criterios: calidad de la sensación, velocidad de transmisión por las fibras, en relación con el lugar del cuerpo donde se exprese, y a la ubicación del nociceptor. La evolución de las condiciones pulpares se clasifican como: pulpitis reversible, pulpitis transicional, pulpitis irreversible y pulpa necrótica.Según su cualidad, el dolor pulpar puede ser punzante o continuo; atendiendo a su aparición, provocado o espontáneo; por su curso, intermitente o continuo; por su localización puede ser limitado a una región, irradiado y referido; y en relación con su intensidad se considera leve, moderado o severo. La capacidad del sistema sensorial nociceptivo en cuanto a discriminar la modalidad, curso temporal, localización e intensidad del estímulo, permite conocer las diferentes etapas de un proceso inflamatorio pulpar(AU)

The nociceptive trigeminal system is a component of the somatosensory system capable of distinguishing four basic variables of stimuli causing tissue damage: quality, time course, location and intensity. A-delta and C fibers, which are related to nociception, are present in dental pulp. Several classifications of pain are used, based on various criteria: quality of the sensation, transmission velocity along fibers, body part where it is expressed, and location of the nociceptor. According to their evolution, pulpal conditions are classified into reversible pulpitis, transitional pulpitis, irreversible pulpitis and necrotic pulp. Pulpal pain has been classified according to the following variables: quality: sharp or continuous; cause: provoked or spontaneous; course: intermittent or continuous; location: limited to a region, radiating or referred; and intensity: mild, moderate or severe. The capacity of the nociceptive sensory system to distinguish the mode, time course, location and intensity of the stimulus makes it possible to recognize the different stages of a pulpal inflammatory process(AU)

Changes in hippocampal orexin 1 receptor expression involved in tooth pain-induced learning and memory impairment in rats.

Orexin 1 receptor signaling plays a significant role in pain as well as learning and memory processes. This study was conducted to assess the changes in orexin 1 receptor expression levels in hippocampus following learning and memory impairment induced by tooth inflammatory pulpal pain. Adult male Wistar rats received intradental injection of 100 µg capsaicin to induce pulpal pain. After recording the pain scores, spatial learning and memory were assessed using Morris Water Maze test. The hippocampal levels of orexin 1 receptor mRNA and protein were determined by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) and immunoblotting respectively. The data showed that capsaicin-induced tooth inflammatory pulpal pain was correlated with learning and memory impairment. Intra-hippocampal injection of orexin A inhibited pain-induced learning and memory impairment. However, orexin 1 receptor antagonist, SB-334867, had no effect on learning and memory impairment. Moreover, capsaicin-induced pain significantly decreased hippocampal orexin 1 receptor mRNA and protein levels. Meanwhile, reversed changes took place in the ibuprofen-pretreated group (p < 0.05). It seems that decrease in orexin 1 receptor density and signaling could be involved in tooth pain-induced learning and memory impairment.

An insight into neurophysiology of pulpal pain: facts and hypotheses.

Pain and pain control are important to the dental profession because the general perception of the public is that dental treatment and pain go hand in hand. Successful dental treatment requires that the source of pain be detected. If the origin of pain is not found, inappropriate dental care and, ultimately, extraction may result. Pain experienced before, during, or after endodontic therapy is a serious concern to both patients and endodontists, and the variability of discomfort presents a challenge in terms of diagnostic methods, endodontic therapy, and endodontic knowledge. This review will help clinicians understand the basic neurophysiology of pulpal pain and other painful conditions of the dental pulp that are not well understood.

An Insight Into Neurophysiology of Pulpal Pain: Facts and Hypotheses

Pain and pain control are important to the dental profession because the general perception of the public is that dental treatment and pain go hand in hand. Successful dental treatment requires that the source of pain be detected. If the origin of pain is not found, inappropriate dental care and, ultimately, extraction may result. Pain experienced before, during, or after endodontic therapy is a serious concern to both patients and endodontists, and the variability of discomfort presents a challenge in terms of diagnostic methods, endodontic therapy, and endodontic knowledge. This review will help clinicians understand the basic neurophysiology of pulpal pain and other painful conditions of the dental pulp that are not well understood.

Diagnostic and clinical factors associated with pulpal and periapical pain

A retrospective survey was designed to identify diagnostic subgroups and clinical factors associated with odontogenic pain and discomfort in dental urgency patients. A consecutive sample of 1,765 patients seeking treatment for dental pain at the Urgency Service of the Dental School of the Federal University of Goiás, Brazil, was selected. Inclusion criteria were pulpal or periapical pain that occurred before dental treatment (minimum 6 months after the last dental appointment), and the exclusion criteria were teeth with odontogenic developmental anomalies and missing information or incomplete records. Clinical and radiographic examinations were performed to assess clinical presentation of pain complaints including origin, duration, frequency and location of pain, palpation, percussion and vitality tests, radiographic features, endodontic diagnosis and characteristics of teeth. Chi-square test and multiple logistic regression were used to analyze association between pulpal and periapical pain and independent variables. The most frequent endodontic diagnosis of pulpal pain were symptomatic pulpitis (28.3 percent) and hyperreactive pulpalgia (14.4 percent), and the most frequent periapical pain was symptomatic apical periodontitis of infectious origin (26.4 percent). Regression analysis revealed that closed pulp chamber and caries were highly associated with pulpal pain and, conversely, open pulp chamber was associated with periapical pain (p<0.001). Endodontic diagnosis and local factors associated with pulpal and periapical pain suggest that the important clinical factor of pulpal pain was closed pulp chamber and caries, and of periapical pain was open pulp chamber.

Um estudo retrospectivo foi realizado para identificar fatores clínicos e de diagnóstico associado com a dor de origem odontogênica. Foram selecionados 1765 pacientes que buscaram tratamento para dor odontogênica no Serviço de Urgência da Faculdade de Odontologia da Universidade Federal de Goiás. Os critérios de inclusão foram dor de origem pulpar ou periapical antes do tratamento dentário (mínimo de 6 meses depois da última consulta odontológica), e os critérios de exclusão foram dentes com anomalias de desenvolvimento e falta de informações ou registros incompletos. Avaliações clínicas e radiográficas foram realizadas para se obter as características clínicas de dor, incluindo origem, duração, frequência e localização da dor, testes de palpação, percussão e vitalidade pulpar, aspectos radiográficos, diagnóstico endodôntico e características dos dentes. Os testes qui-quadrado e regressão logística múltipla foram utilizados para verificar a associação entre a dor de origem pulpar e periapical e variáveis independentes. O diagnóstico endodôntico de dor de origem pulpar mais frequente foi pulpite sintomática (28,3 por cento) seguido por pulpalgia hiper-reativa (14,4 por cento), e o mais frequente de dor de origem periapical foi periodontite apical sintomática infecciosa (26,4 por cento). Análise de regressão revelou que câmaras pulpares fechadas e cáries estavam altamente associadas à dor pulpar e, inversamente, câmara pulpar aberta estava associada à dor periapical (p<0,001). O diagnóstico endodôntico e fatores locais associados com dor de origem pulpar e periapical sugerem que os fatores clínicos importantes das dores pulpares foram câmaras pulpares fechadas e cáries, e de dor periapical foi câmara pulpar aberta.