Exploring Undergraduate Students' Perspectives on Endodontic Treatment: A Cross-Sectional Study in Makkah.

Background Students at two universities in Saudi Arabia found endodontics or root canal treatment (RCT) difficult due to challenges in the procedures. Until now, there has been no evidence that Umm Al-Qura University students face difficulties when performing RCT. Therefore, this study aims to explore students' perceptions of the critical steps in RCT. Methods A survey was conducted among 146 dental students at Umm Al-Qura University, Makkah, Saudi Arabia to assess their perceptions and challenges during RCT. Demographic information was collected in the first section, while the second section focused on identifying difficulties encountered during endodontic treatment stages. All participants provided signed electronic consent, and the study was approved by the university's institutional review board. Chi-squared tests were used to analyze the results. Results In a survey of 123 students, 94 (76.2%) found the endodontic specialty acceptable compared to other dental specialties (P < 0.001). Eighty-eight (71.5%) found RCT on the molars difficult (P < 0.001). Most students, 104 (84.6%), chose to have more clinical training to improve their clinical endodontic skills, and 77 (62.6%) chose to increase the number of instructors per student in the clinic (P < 0.05). Difficulties in performing RCT on premolars and during root canal obturation were statistically correlated with the academic year of the student (P < 0.05). Conclusion Dental students often struggle when performing RCT on molars. Some difficulties during RCT are correlated with the academic year of the student. Finally, from the students' perspective, improving endodontic skills involves providing better clinical training opportunities and increasing instructor-to-student ratios.

The effect of educational animation compared to leaflets on patients' knowledge regarding root canal treatment: a randomized controlled trial.

BACKGROUND: Incorporating video as a tool for education offers a multitude of advantages. However, it is unknown what is the best educational tool to use for increasing public awareness, consequently reducing fear about root canal treatment. For this reason, this study aimed to compare the effectiveness of educational animation and leaflets as delivery methods for providing information on root canal treatment to patients and to assess their ability to retain the information. METHODS: One hundred fifty adult volunteers were recruited via social media and Umm Al-Qura University Dental Hospital to participate in this randomized control trial study. The volunteers were divided into the study group (SG) and the control group (CG). The SG was provided with information through animations created by the research team, while the CG received the same information through a leaflet. Pre-intervention (T1), immediate post-intervention (T2), and one-month post-intervention (T3) validated questionnaires were completed by the participants to assess the changes in their knowledge. To evaluate the impact of the information delivery method, the knowledge scores of T2 and T3 were compared to T1 within each group using Paired T-tests. Additionally, the study compared the knowledge scores of the two groups using unpaired T-tests. The significance level was set at a P-value of less than 0.05. RESULTS: A significant improvement in endodontic therapy knowledge among the participants in both groups (T1 compared to T2 in the same group) was noted (P < 0.050). However, when comparing T2 between groups, no significant difference was found in delivering the information and improving the knowledge (P = 0.080). Still, the mean differences between T1 and T2, as well as T1 and T3, were greater (P < 0.050) in the SG than in the CG. Furthermore, the total knowledge score in the SG at T3 was significantly higher than the CG. CONCLUSION: Both educational animation and leaflets are practical tools to increase patients' awareness about root canal treatment. However, educational videos are more effective than leaflets in delivering and retaining information about root canal treatment. TRIAL REGISTRATION: This study was retrospectively registered as a randomized control trial at the ISRCTN registry with the document number ISRCTN18413241, 15/05/2023.

Pain after emergency treatments of symptomatic irreversible pulpitis and symptomatic apical periodontitis in the permanent dentition: a systematic review of randomized clinical trials.

Background: Symptomatic irreversible pulpitis (SIP) or symptomatic apical periodontitis (SAP) are two painful conditions often warranting emergency treatment. The most common emergency treatments supported by evidence are pulpotomy and pulpectomy and are normally performed under time-constrained circumstances. However, there is no strong evidence of which treatment suggested in literature a clinician can use to reduce endodontic pain effectively. Therefore, the aim of this systematic review is to investigate the present knowledge on postoperative pain related to the two types of emergency treatments available for treating SIP and SAP. Methods: Randomized controlled trials investigating postoperative pain after emergency treatments (pulpotomy and/or pulpectomy) on permanent dentition with signs and symptoms of SIP and/or SAP were searched in three major databases from 1978 until 2022. Risk of bias was assessed with Cochrane's tool. Results: Only five studies fulfilled the inclusion criteria. The included studies indicated that pulpotomy and pulpectomy are both suitable treatment options for SAP and SIP, as they provide sufficient alleviation of pain in permanent dentition. However, inconsistent results were found between the included trials on which emergency treatment is more effective in reducing pain. Cochrane's tool revealed that the studies had a low risk of bias. Limitations found in the design of the included randomized control trials decreased the level of evidence. None of the included studies accounted for essential confounding variables, such as factors affecting pain (including the psychological aspects). Moreover, possible non-odontogenic pain was not assessed, and therefore, it was not excluded; hence, affecting the internal validity of the studies. Conclusion: There are controversies within the available randomized control trials on which treatment is most effective in reducing emergency pain. This could be due to some weaknesses in the design of the clinical trials. Thus, further well-designed studies are warranted to draw conclusions on which emergency treatment is more effective in reducing pain. Systematic Review Registration: PROSPERO (CRD42023422282).

Nerve growth factor and glutamate increase the density and expression of substance P-containing nerve fibers in healthy human masseter muscles.

Nocifensive behavior induced by injection of glutamate or nerve growth factor (NGF) into rats masseter muscle is mediated, in part, through the activation of peripheral NMDA receptors. However, information is lacking about the mechanism that contributes to pain and sensitization induced by these substances in humans. Immunohistochemical analysis of microbiopsies obtained from human masseter muscle was used to investigate if injection of glutamate into the NGF-sensitized masseter muscle alters the density or expression of the NMDA receptor subtype 2B (NR2B) or NGF by putative sensory afferent (that express SP) fibers. The relationship between expression and pain characteristics was also examined. NGF and glutamate administration increased the density and expression of NR2B and NGF by muscle putative sensory afferent fibers (P < 0.050). This increase in expression was greater in women than in men (P < 0.050). Expression of NR2B receptors by putative sensory afferent fibers was positively correlated with pain characteristics. Results suggest that increased expression of peripheral NMDA receptors partly contributes to the increased pain and sensitivity induced by intramuscular injection of NGF and glutamate in healthy humans; a model of myofascial temporomandibular disorder (TMD) pain. Whether a similar increase in peripheral NMDA expression occurs in patients with painful TMDs warrants further investigation.

Sex-related differences in response to masseteric injections of glutamate and nerve growth factor in healthy human participants.

The neurophysiological mechanisms underlying NGF-induced masseter muscle sensitization and sex-related differences in its effect are not well understood in humans. Therefore, this longitudinal cohort study aimed to investigate the effect of NGF injection on the density and expression of substance P, NMDA-receptors and NGF by the nerve fibers in the human masseter muscle, to correlate expression with pain characteristics, and to determine any possible sex-related differences in these effects of NGF. The magnitude of NGF-induced mechanical sensitization and pain during oral function was significantly greater in women than in men (P < 0.050). Significant positive correlations were found between nerve fiber expression of NMDA-receptors and peak pain intensity (rs = 0.620, P = 0.048), and expression of NMDA-receptors by putative nociceptors and change in temporal summation pain after glutamate injection (rs = 0.561, P = 0.003). In women, there was a significant inverse relationship between the degree of NGF-induced mechanical sensitization and the change in nerve fiber expression of NMDA-receptors alone (rs = - 0.659, P = 0.013), and in combination with NGF (rs = - 0.764, P = 0.001). In conclusion, women displayed a greater magnitude of NGF-induced mechanical sensitization that also was associated with nerve fibers expression of NMDA-receptors, when compared to men. The present findings suggest that, in women, increased peripheral NMDA-receptor expression could be associated with masseter muscle pain sensitivity.

Density of nerve fibres and expression of substance P, NR2B-receptors and nerve growth factor in healthy human masseter muscle: An immunohistochemical study.

BACKGROUND: In skeletal muscle, free nerve endings are mostly located within the connective tissue. However, the distribution of sensory afferent fibres in healthy human masseter muscle tissues has not been studied. OBJECTIVES: Primarily to investigate human masseter muscle nerve fibre densities as well as expression of NR2B receptors, substance P (SP) and nerve growth factor (NGF), and secondarily to compare this between a) nerve fibres associated with myocytes and within connective tissue; b) sexes; and c) ages. METHODS: Microbiopsies of the masseter muscle were obtained from 60 sex- and age-matched healthy participants. Biopsy sections were analysed using immunohistochemistry and were visualised with a Leica TCS SPE confocal microscope. The Mann-Whitney U test was used for statistical analyses. RESULTS: The density of nerve fibres within connective tissue was significantly greater than in nerve fibres associated with myocytes (P < .001). Nerve fibres within connective tissue expressed SP alone or together with NR2B significantly more often than those associated with myocytes (P < .001). The frequency of nerve fibres, which expressed SP alone or in combination with NR2B or NGF, was significantly greater in women than in men (P < .050). Moreover, the co-expression of the three markers together was inversely correlated with age in women (P < .002). CONCLUSIONS: There is a higher density and greater expression of sensory nerve fibres within the connective tissue than associated with myocytes in healthy human masseter muscle. This suggests that nerve fibres within connective tissue are more involved in nociception than nerve fibres associated with myocytes.

Functional Change in Experimental Allodynia After Glutamate-Induced Pain in the Human Masseter Muscle.

Background: Glutamate, as well as nerve growth factor (NGF), is involved in nociception from peripheral tissues, such as muscles. However, the potential interaction between glutamate and NGF still remains unclear. This study investigated the interaction between glutamate-induced masseter muscle pain and NGF-induced allodynia on pain perception and jaw function in healthy individuals, and any possible sex differences in the response. Materials and Methods: Thirty pain-free adult participants (15 men and 15 women, mean age ± SD: 24 ± 4 years) participated in this study consisting of three sessions (Day 0, Day 3, and Day 4). NGF (5 µg/mL, 1.0 mL) was injected into the masseter muscle on Day 0 to induce muscle allodynia. On Day 3, glutamate (1M, 0.2 mL) was injected into the same masseter muscle. Before and after injections on Day 0 and 3, and post-injection (Day 4), spontaneous pain, temporal summation pain, as well as functional pain and fatigue in response to chewing were assessed with validated scales, and the pressure pain threshold (PPT) was recorded. Results: Spontaneous pain intensity was significantly higher after glutamate than NGF (P < 0.001). PPTs, temporal summation pain and functional measures were all reduced 3 days after NGF injection (P's < 0.001). Injection of glutamate on Day 3 did not further affect PPTs or temporal summation pain and there were no sex differences in the effects (P > 0.189). Chewing pain (P = 0.022) and fatigue increased after glutamate injection to a higher degree in the women than men (P = 0.037). Conclusion: Taken together, while glutamate injected into the NGF-sensitized muscle was painful, it did not alter muscle tenderness in women vs. men. However, pain and fatigue evoked by jaw function were higher in women after glutamate injection. This suggest that sex differences reported for masseter myalgia, mimicked by glutamate and NGF mediated pain in this study, may be greater for measures of perceived jaw function, which should be considered in a clinical evaluation.