Non-coding RNAs in endodontic disease.

The immunocompetence and regeneration potential of the dental pulp and its surrounding apical tissues have been investigated extensively in the field of endodontics. While research on the role of non-coding RNAs in these tissues is still in its infancy, it is envisioned that improved understanding of the regulatory function of ncRNAs in pulpal and periapical immune response will help prevent or treat endodontic disease. Of particular importance is the role of these RNAs in regenerating the dentin-pulp complex. In this review, we highlight recent progress on the role of non-coding RNAs in the immune response to endodontic infection as well as the repair and regenerative response to injury.

Identification and validation of novel biomarkers and therapeutics for pulpitis using connectivity mapping.

AIM: To create an irreversible pulpitis gene signature from microarray data of healthy and inflamed dental pulps, followed by a bioinformatics approach using connectivity mapping to identify therapeutic compounds that could potentially treat pulpitis. METHODOLOGY: The Gene Expression Omnibus (GEO) database, an international public repository of genomics data sets, was searched for human microarray datasets assessing pulpitis. An irreversible pulpitis gene expression signature was generated by differential expression analysis. The statistically significant connectivity map (ssCMap) method was used to identify compounds with a highly correlating gene expression pattern. qPCR was used to validate novel pulpitis genes. An ex vivo pulpitis model was used to test the effects of the compounds identified, and the level of inflammatory cytokines was measured with qPCR, ELISA and multiplex array. Means were compared using the t-test or ANOVA with the level of significance set at p ≤ .05. RESULTS: Pulpitis gene signatures were created using differential gene expression analysis at cutoff points p = .0001 and .000018. Top upregulated genes were selected as potential pulpitis biomarkers. Among these, IL8, IL6 and MMP9 were previously identified as pulpitis biomarkers. Novel upregulated genes, chemokine (C-C motif) ligand 21 (CCL21), metallothionein 1H (MT1H) and aquaporin 9 (AQP9) were validated in the pulp tissue of teeth clinically diagnosed with irreversible pulpitis using qPCR. ssCMap analysis identified fluvastatin (Statin) and dequalinium chloride (Quaternary ammonium) as compounds with the strongest correlation to the gene signatures (p = .0001). Fluvastatin reduced IL8, IL6, CCL21, AQP9 (p < .001) and MMP9 (p < .05) in the ex vivo pulpitis model, while dequalinium chloride reduced AQP9 (p < .001) but had no significant effect on the other biomarkers. CONCLUSIONS: AQP9, MT1H and CCL21 were identified and validated as novel biomarkers for pulpitis. Fluvastatin and dequalinium chloride identified by the ssCMap as potential therapeutics for pulpitis reduced selected pulpitis biomarkers in an ex vivo pulpitis model. In vivo testing of these licenced drugs is warranted.

Predicting the response of the dental pulp to SARS-CoV2 infection: a transcriptome-wide effect cross-analysis.

Pulpitis, inflammation of the dental pulp, is a disease that often necessitates emergency dental care. While pulpitis is considered to be a microbial disease primarily caused by bacteria, viruses have also been implicated in its pathogenesis. Here, we determined the expression of the SARS-CoV2 receptor, angiotensin converting enzyme 2 (ACE2) and its associated cellular serine protease TPMRSS2 in the dental pulp under normal and inflamed conditions. Next, we explored the relationship between the SARS-CoV-2/human interactome and genes expressed in pulpitis. Using existing datasets we show that both ACE2 and TPMRSS2 are expressed in the dental pulp and, that their expression does not change under conditions of inflammation. Furthermore, Master Regulator Analysis of the SARS-CoV2/human interactome identified 75 relevant genes whose expression values are either up-regulated or down-regulated in both the human interactome and pulpitis. Our results suggest that the dental pulp is vulnerable to SARS-CoV2 infection and that SARS-CoV-2 infection of the dental pulp may contribute to worse outcomes of pulpitis.

Genomic and physiological analyses reveal that extremely thermophilic Caldicellulosiruptor changbaiensis deploys uncommon cellulose attachment mechanisms.

The genus Caldicellulosiruptor is comprised of extremely thermophilic, heterotrophic anaerobes that degrade plant biomass using modular, multifunctional enzymes. Prior pangenome analyses determined that this genus is genetically diverse, with the current pangenome remaining open, meaning that new genes are expected with each additional genome sequence added. Given the high biodiversity observed among the genus Caldicellulosiruptor, we have sequenced and added a 14th species, Caldicellulosiruptor changbaiensis, to the pangenome. The pangenome now includes 3791 ortholog clusters, 120 of which are unique to C. changbaiensis and may be involved in plant biomass degradation. Comparisons between C. changbaiensis and Caldicellulosiruptor bescii on the basis of growth kinetics, cellulose solubilization and cell attachment to polysaccharides highlighted physiological differences between the two species which are supported by their respective gene inventories. Most significantly, these comparisons indicated that C. changbaiensis possesses uncommon cellulose attachment mechanisms not observed among the other strongly cellulolytic members of the genus Caldicellulosiruptor.

Effect of a single dose of low-level laser therapy on spontaneous and chewing pain caused by elastomeric separators.

INTRODUCTION: The aim of this study was to see the effect of a single dose of low-level laser therapy on spontaneous and chewing pain after the placement of elastomeric separators. METHODS: Eighty-eight patients were randomly selected for this single-blind study. Elastomeric separators were placed mesial and distal to the permanent first molars in all quadrants. Both arches were divided into experimental and control sides. The experimental sides were treated with low-level laser therapy on 3 points on the buccal mucosa for 20 seconds each, with a 940-nm gallium-aluminum-arsenic diode laser on continuous mode and power set at 200 mW. The other side received placebo laser therapy without turning on the laser. A numeric rating scale was used to assess the intensity of spontaneous and chewing pain for the next 7 days. The independent sample t test and repeated-measures analysis of variance with the post hoc Tukey test was used to analyze the results. RESULTS: Significant differences were found in spontaneous and chewing pain among both groups (P <0.05). CONCLUSIONS: A single dose of low-level laser therapy can be an efficient modality to reduce the postoperative pain associated with the placement of elastomeric separators.

Assessment of Prevalence and Causative Factors for Replacement of Composite and Amalgam Restorations: An Observational Study.

Aim: This study intends to evaluate the frequency and causes of replacement for failed amalgam and composite dental restorations. Methodology: A cross-sectional study comprising female patients with failed permanent composite and amalgam restorations aged 15-60 years old was carried out at the dental clinics of Qassim University. Using a self-structured proforma, demographic data and causes for restoration failure were recorded. The effectiveness of the restorations was assessed by using the Ryge criteria after performing clinical and radiographic examinations. The Statistical Package for Social Science was used for the statistical analysis. Results: It is found that 84.6% of the 299 unsuccessful restorations examined were composite, and 15.4% were amalgam. The main reason for dental failure for both amalgam (95.6%) and composite (93.28%) restorations was secondary caries. Failure of amalgam restoration was largely caused by poor marginal adaptation. With varied incidences between amalgam and composite restorations, typical complaints included discomfort, sensitivity, pain, and food impaction with soreness. The main justification for replacement in amalgam restorations was sensitivity. Repair and replacement rates were similar for amalgam, composite, and mandibular/maxillary restorations. Moreover, 21.1% of individuals overall reported no symptoms, with 8.7% in the amalgam group and 23.3% in the composite group with significant differences (χ2 = 34.28, P = 0.001). Conclusion: According to the current study, secondary caries was found to be the main reason for both amalgam and composite restoration failure. The main problems reported were sensitivity, discomfort, and pain with amalgam showing more sensitivity-related failures.

Radiographic Evaluation of Regenerative Endodontic Procedures and Apexification Treatments with the Assessment of External Root Resorption.

INTRODUCTION: This multicentered cohort study evaluated the radiographic outcomes of regenerative endodontic procedures (REPs) and apexification treatments (APEX) of immature teeth with endodontic disease. MATERIALS AND METHODS: This cohort study included a retrospective record review and prospective data collection of pediatric patients with teeth treated with REPs or APEX between 2005 and 2014. Data including the presence of a periapical lesion, external root resorption, obliteration, apical hard tissue, apical closure, intracanal calcifications, and radiographic root area (RRA) change based on measurements were collected/measured from radiographic images. Univariate and multivariate analyses were conducted. RESULTS: The cohort included 190 subjects (204 teeth (92 REPs; 112 APEX)). The frequency of pretreatment periapical pathology was similar between cases in which the clinical treatment failed versus successful treatment cases. However, the frequency of pretreatment external root resorption was higher in failed cases than in successful cases (P = .007). The mean RRA change was greater than twenty percent in 21% of the REPs cases. In traumatized teeth, REPs resulted in less hard tissue formation than other endodontic disease etiologies measured by RRA (P = .001). Fifty-three percent of cases with ERR (16/30) showed signs of healing/arrest and were mostly treated with REPs (11/16). CONCLUSIONS: The presence of ERR negatively affected the treatment outcome. There was significant variability in RRA change in REPs. Signs of healing/arrest of the resorptive lesion were radiographically visible in many cases treated with REPs.

Assessing the Efficacy of Planmeca ProMax® 3D Cone-Beam CT Machine in the Detection of Root Fractures With Varied Metal Artifact Reduction Settings and Three Kilovoltage Peak Levels.

BACKGROUND: This study aims to examine the accuracy of cone-beam computed tomography (CBCT) machines in detecting root fracture when using different metal artifact reduction (MAR) settings at different kilovoltage peak (kVp) levels. METHODOLOGY: Sixty-six tooth roots were treated endodontically using a standardized technique. Of these, 33 roots were randomly selected to be fractured; the other 33 roots were intact and used as controls. The roots were placed randomly in prepared beef ribs to mimic the alveolar bone. Imaging was performed by Planmeca ProMax® 3D (Planmeca, Helsinki, Finland) using different MAR settings (no, low, mid, and high) at three different levels of kVp: 70, 80, and 90. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated. RESULTS: There was a significant difference in accuracy when using different MAR settings within the group of 70 kVp. Likewise, within the group of 90 kVp. There was no significant difference between different MAR settings at 80 kVp. Using low MAR/90 kVp had significantly higher accuracy relative to other MAR settings at 90 kVp; it also had the highest values of sensitivity, specificity, and AUC in the study. Using mid and high MAR at 70 kVp or 90 kVp decreased accuracy significantly. Mid MAR/90 kVp was the least effective setting in this study. CONCLUSIONS:  Using low MAR at 90 kVp significantly increased the accuracy within the group of 90 kVp. In contrast, mid MAR and high MAR in 70 and 90 kVp, respectively, decreased accuracy significantly.

Undergraduate Students' and Interns' Perception towards Learning Environment at Dental Clinics, Qassim University, Saudi Arabia.

Background: Dental clinical educational environment plays a critical part in the inculcation of skills and enhancement of knowledge for the dental students. The objective was to assess undergraduate dental students' and interns' perceptions towards the clinical learning environment. Methods: Current cross-sectional study was conducted from December 2020 to February 2021, using the 24-item dental clinical learning environment inventory (DECLEI) on a six point Likert scale. The possible range of cumulative score for DECLEI was from 0 to 100 (interpretation poor to excellent). The inventory was emailed to 111 students and interns at College of Dentistry, Qassim University. The relationship between the independent variables and DECLEI scores was determined by using Pearson correlation test. SPSS version-23 was used for statistical analysis. Results: Overall response rate was 78.37%. The mean DECLEI score was noted as 67.5 ± 17.98. Among the factors, the highest mean score was documented for the systematic self-evaluation and the lowest mean score was observed for the item related to patients' punctuality for appointments. A factor-wise analysis of three subscales of DECLEI demonstrated the respondents had good perception towards all subscales with the highest mean score (72.3 ± 18.06) for Factor III and lowest mean score (61.3 ± 19.81) for Factor II. Overall, the DECELI was found to be reliable with the Cronbach's Alpha value of 0.94. The Pearson's correlation test showed the weak positive insignificant correlation of mean DECLEI score with gender and categories. Conclusions: Present study indicated more positive than negative perceptions of the dental students related to their clinical learning environment. The DECLEI helped in recognizing both strengths and shortcomings of the dental clinical learning environment.

Self-doubt masked in success: Identifying the prevalence of impostor phenomenon among undergraduate dental students at Qassim University.

Objective: To investigate the prevalence of impostor phenomenon (IP) among undergraduate dental students and explore its relationship with gender and academic year. Methods: This study involved observational cross-sectional research involving undergraduate dental students (first to fifth year) at Qassim University Dental School, between February and April 2021. An electronically administered, 20-item pre-validated Clance Impostor Phenomenon Scale (CIPS) was used for data collection. Data analysis was performed using SPSS version 23. Mean IP scores of both genders were compared using t-tests, one-way ANOVA and Post-Hoc tests to establish the relationship between year-wise IP scores. Results: The response rate was 80.59% (162 respondents). The results indicated that 8.8% of the participants had mild IP experiences, 84.1% had moderate to severe IP experiences, and 7.05% exhibited intense IP experiences. The mean IP score was highest and lowest in the third and fourth-year dental students, respectively. A statistically significant relationship was identified between year wise IP scores, while no significant difference was observed based on gender. Conclusions: Impostor phenomenon is prevalent in substantial frequencies amongst dental students. This may have damaging physical and mental effects with negative consequences and could subsequently affect their intellectual and professional developments. The implementation of a modified curriculum and self-development plans are some of the recommended solutions.

The Effect of Calcium Hydroxide, Triple Antibiotic Paste and Chlorhexidine on Pain in Teeth with Symptomatic Apical Periodontitis: A Randomised Controlled Trial.

BACKGROUND: One of the main reasons for post endodontic pain is the polymicrobial intracanal flora that may survive the initial disinfection. A single antimicrobial agent might not provide adequate disinfection, and an antimicrobial combination such as triple antibiotic paste was tested to achieve this goal. AIM: The study aimed to assess the efficacy of three intra-canal medicaments on post root canal preparation pain. MATERIALS AND METHODS: Eighty patients with single-rooted necrotic teeth and symptomatic apical periodontitis were randomly assigned to four treatment groups (n = 20). Their preoperative pain was recorded on Wong-Baker's FACES pain rating scale. After chemo-mechanical canal preparation, intracanal medications were applied to the groups (Group 1 (20% calcium hydroxide), Group 2 (2% chlorhexidine), Group 3 (tri-antibiotic paste), Group 4 (no medication (Control group)). Patients were instructed to record pain on the Wong-Baker FACES pain rating scale at 4, 48, 72 and 96 hrs, postoperatively. Pain scores were analyzed using a one-way ANOVA test and Tukey's post hoc test and, if significant, Dunn's test was used for pair-wise comparisons. The significance level was set at a p-value ≤ 0.05. RESULTS: Tukey's post hoc test revealed significantly lower pain scores in Group 3 compared with other groups at all follow up intervals. Dunnett's test showed significantly lower pain in Group 3 compared with the Control group at 48, 72 and 96 hrs, postoperatively. CONCLUSIONS: Triple-antibiotic paste showed effective pain control as an intracanal medication on necrotic teeth with symptomatic apical periodontitis.

The relationship between resting arterial blood pressure and acute postoperative pain in endodontic patients.

AIMS: To evaluate the relationship between preoperative resting arterial blood pressure and postoperative pain in patients undergoing nonsurgical root canal therapy. METHODS: Written informed consent was obtained from normotensive patients seeking treatment for teeth with a preoperative diagnosis of pulpal necrosis and periradicular periodontitis. Preoperative resting blood pressure was recorded, and nonsurgical root canal therapy was initiated using a standardized protocol. Patients recorded their pre- and postoperative pain intensity on a 100-mm visual analog scale (VAS) for 7 days after the procedure. A linear regression model to predict postoperative VAS intensity used preoperative pain and blood pressure values as covariates. Pearson correlations were calculated to assess the relationship between the measures of preoperative blood pressure and both pre- and postoperative pain. RESULTS: After controlling for preoperative pain, significant correlations were observed between preoperative systolic blood pressure and postoperative pain (P < .05), as well as between preoperative pulse pressure and postoperative pain (P < .005) on day 1. CONCLUSION: This study has provided further evidence of a functional interaction between the cardiovascular and trigeminal pain regulatory systems. Understanding this complex relationship may lead to enhanced pain management strategies.

Wavelet Guided 3D Deep Model to improve Dental Microfracture Detection.

Epidemiological studies indicate that microfractures (cracks) are the third most common cause of tooth loss in industrialized countries. An undetected crack will continue to progress, often with significant pain, until the tooth is lost. Previous attempts to utilize cone beam computed tomography (CBCT) for detecting cracks in teeth had very limited success. We propose a model that detects cracked teeth in high resolution (hr) CBCT scans by combining signal enhancement with a deep CNNbased crack detection model. We perform experiments on a dataset of 45 ex-vivo human teeth with 31 cracked and 14 controls. We demonstrate that a model that combines classical wavelet-based features with a deep 3D CNN model can improve fractured tooth detection accuracy in both micro-Computed Tomography (ground truth) and hr-CBCT scans. The CNN model is trained to predict a probability map showing the most likely fractured regions. Based on this fracture probability map we detect the presence of fracture and are able to differentiate a fractured tooth from a control tooth. We compare these results to a 2D CNN-based approach and we show that our approach provides superior detection results. We also show that the proposed solution is able to outperform oral and maxillofacial radiologists in detecting fractures from the hr-CBCT scans. Early detection of cracks will lead to the design of more appropriate treatments and longer tooth retention.

Patient Centered Outcomes among a Cohort Receiving Regenerative Endodontic Procedures or Apexification Treatments.

INTRODUCTION: This multicentered cohort study evaluated factors associated with patient-centered outcomes of immature permanent teeth that received regenerative endodontic procedures (REPs) or apexification treatment (APEX). METHODS: A record review identified teeth treated with REPs or APEX between September 2005 and December 2014. Data regarding treatment and patient-centered outcomes were extracted from records with a 3-month minimum recall. When possible, participants presented for an in-person prospective research visit. Patient-centered success was defined as an asymptomatic, functional tooth not requiring further endodontic or surgical intervention after completion of the original treatment during the study observation. Risk ratios and adjusted and unadjusted Cox proportional hazard ratios were calculated. RESULTS: The analytic cohort of 187 individuals included 211 teeth (93 REPs and 118 APEX) with an average follow-up of 32 months. Most cases were successful (81% REPs and 92% APEX) and survived the observation period (96% REPs and 97% APEX). The success rate of REPs was lower than APEX and decreased more rapidly over time. Cox regression analysis demonstrated that when controlling for other variables, the association between treatment type and outcome is not significant. Preoperative infection, teeth with more immature roots, and REP treatment are potentially important predictors. Among teeth receiving REPs, a lower failure rate was observed for teeth that received multiantibiotic paste (3/43) compared with calcium hydroxide (11/45). CONCLUSIONS: Teeth receiving REPs required clinical intervention earlier than teeth that received APEX treatment, although a preoperative abscess and more immature root also affected this outcome. Using multiantibiotic paste versus calcium hydroxide in REPs may improve success.

Pharmacological Management of Acute Endodontic Pain.

Pain associated with infections of the tooth pulp and periapical tissues is intense and often the most common reason for patients seeking emergency dental care. Effective management of acute dental pain requires a deep understanding of pain mechanisms, which enables accurate diagnosis and definitive treatment. While drugs are only used as an adjunct to definitive dental treatment, a thorough understanding of their mechanism of action and effectiveness enables clinicians to effectively control intra-operative and post-operative pain and prevent persistent pain. This review describes how pain is detected, processed, and perceived. It also provides information on evidence-based strategies on the use of different classes of drugs to effectively manage endodontic pain.

Actions Speak Louder Than Words: Impact Of Kinesics On Undergraduate Medical Education.

BACKGROUND: Nonverbal communication constitutes significant proportion of human communication besides spoken words. This study explored teacher's perceptions about impact of kinesics (facial expressions, gestures, head movements and postures) on undergraduate medical education within a classroom setting. METHODS: A survey-based exploratory research was carried out from July-August 2020. Medical teachers from two private dental colleges of Islamabad were included in the sampling frame. The survey questions were validated and approved by all authors before execution. Frequencies and percentages of closed-ended questions were calculated while thematic analysis for open-ended questions was done by all authors to get consensus on themes, hence ensuring analytical triangulation. RESULTS: Forty-six teachers responded to the survey. The most frequently shown facial expressions were 'happiness and enthusiasm' (76.1%) creating friendly, conducive, and motivating learning environment. 'Smile' was considered powerful communicative signal (95.7%) whereas 'anger' was thought to be communication barrier leading to stressful and demotivating learning environment. Neutral expressions were considered helpful to maintain class decorum. 'OK sign with raised thumb' (50%) was found helpful to develop special teacher-student connection and 'head nod' (84.8%) was encouraging students to continue giving answers. Standing posture (81%) exhibited teacher's commitment towards teaching and produced active learning environment. CONCLUSIONS: Teachers should start lecture with welcoming facial expressions, i.e., smile to build rapport with students. Anger should be avoided as it demotivates students by making learning environment stressful. We need to train faculty regarding effective use of nonverbal communication strategies to improve student's learning experience and to create positive learning environment.

The Relationship of Orofacial Pain and Dental Health Status and Oral Health Behaviours in Facial Burn Patients.

This study aims to examine the association of orofacial pain and oral health status and oral health behaviours in facial burn patients. The participants in this cross-sectional study were randomly recruited from the Burn Care Center, Institute of Medical Sciences, Islamabad, Pakistan. An intraoral evaluation was carried out to record the DMFT and OHI-S. A self-administered questionnaire was used to collect information on sociodemographic status, brushing frequency, and dental visits. Orofacial pain during mandibular movement was assessed using the Visual Analogue Scale (VAS). Psychological status was assessed using the Generalized Anxiety Disorder Scale and Impact of Events Scale. ANOVA and simple and multiple linear regression tests were used to analyse the data. From the 90 facial burn patients included, the majority were below 34 years of age, female, single or divorced, and unemployed. The mean DMFT was 10.7, and 71% had poor oral hygiene. 56% of the participants had moderate-to-severe anxiety, and 68% had posttraumatic stress disorder. 53% of the participants had moderate-to-severe pain during mouth opening or moving the mandible with a mean score of 41.5. Analyses showed that orofacial pain was associated with less frequent brushing, irregular dental visits, greater DMFT score, and more plaque accumulation (OHI-S). It was also associated with employment status, the severity of a burn, anxiety, and stress. The treatment and management of dental and oral conditions in burn patients need judicious balance in controlling and accurate assessment of the pain and improving psychological problems in burn patients.

Dental microfracture detection using wavelet features and machine learning.

Microfractures (cracks) are the third most common cause of tooth loss in industrialized countries. If they are not detected early, they continue to progress until the tooth is lost. Cone beam computed tomography (CBCT) has been used to detect microfractures, but has had very limited success. We propose an algorithm to detect cracked teeth that pairs high resolution (hr) CBCT scans with advanced image analysis and machine learning. First, microfractures were simulated in extracted human teeth (n=22). hr-CBCT and microCT scans of the fractured and control teeth (n=14) were obtained. Wavelet pyramid construction was used to generate a phase image of the Fourier transformed scan which were fed to a U-Net deep learning architecture that localizes the orientation and extent of the crack which yields slice-wise probability maps that indicate the presence of microfractures. We then examine the ratio of high-probability voxels to total tooth volume to determine the likelihood of cracks per tooth. In microCT and hr-CBCT scans, fractured teeth have higher numbers of such voxels compared to control teeth. The proposed analytical framework provides a novel way to quantify the structural breakdown of teeth, that was not possible before. Future work will expand our machine learning framework to 3D volumes, improve our feature extraction in hr-CBCT and clinically validate this model. Early detection of microfractures will lead to more appropriate treatment and longer tooth retention.

A prospective study of outcome from rubber band ligation in third degree haemorrhoids.

OBJECTIVE: To evaluate the efficacy and effectiveness of rubber band ligation on 3rd degree haemorrhoids. METHODS: Study was done at Surgical Unit, Civil Hospital Karachi, during a period of 19 months from December 2006 to July 2008. Out of 344 patients 80 patients were included in the study with 3rd degree internal haemorrhoids and were treated with Rubber band ligation (RBL). Outcome data was recorded for success of treatment. RESULT: Among 80 patients, 77 (96.25%) were symptom free. After completion of treatment, 1 (16.66%) out of 5 patients had the complaint of pain, 2 (2.85%) out of 70 had complaints of constipation. Before start of treatment 5 (6.25%) patients complained of bleeding per rectum and 73 (91.25%) complained of manually reducible/prolapsed haemorrhoids. Both complaints were cured 100% after treatment. CONCLUSION: RBL is an efficient, cost-effective and simple out patient procedure for symptomatic third degree haemorrhoids with minimum complications. RBL is a reliable, safe procedure requiring no hospitalization and no use of any anaesthetic drugs.

Quantitative Assessment of Mechanical Allodynia and Central Sensitization in Endodontic Patients.

INTRODUCTION: Patients seeking endodontic treatment commonly present with reduced mechanical pain thresholds (ie, mechanical allodynia [MA]) in the offending teeth. In patients with moderate to severe pain, MA may manifest in the teeth contralateral to the offending teeth because of the onset of central sensitization (CS). We hypothesize that there are quantitative differences in MA and CS in patients with different pulp and periradicular diagnoses. METHODS: Patients (n = 70) receiving endodontic treatment in the graduate endodontic clinic at the University of Texas Health Science Center at San Antonio and healthy volunteers (n = 10) were included in this cross-sectional study. The mechanical pain threshold from molar teeth was measured by a digital bite force transducer on the offending tooth (ipsilateral) and the contralateral tooth. Ipsi- and contralateral MA among different endodontic diagnoses were analyzed using the Kruskal-Wallis with Dunn post hoc test and the Student t test for differences between sexes. Multivariate regression models analyzed predictors for MA and CS. RESULTS: Periradicular diagnoses of asymptomatic apical periodontitis, symptomatic apical periodontitis, and chronic apical abscess cases were significantly associated with MA. CS, seen as contralateral MA, was only detected in pulpal diagnosis of symptomatic irreversible pulpitis, previously initiated treatment, symptomatic apical periodontitis, and chronic apical abscess. Females experienced significantly lower pain thresholds than males on both sides. MA and CS were significantly correlated in both sexes. The preoperative pain level and duration were significant predictors for MA and CS only in female patients. Lastly, age was a significant predictor for MA in females. CONCLUSIONS: The magnitude of MA and CS varied with different endodontic diagnoses, with CS being correlated with increases in MA. Only in female patients were age, preoperative pain duration, and intensity significant predictors for the development of MA and CS.