The Incidence of Devitalization of Vital Teeth Associated with Pathologies of the Jaws Following Surgical Intervention: A Mixed-case Study.

AIM: The purpose of this mixed-case study is to explore the incidence of pulp necrosis of vital teeth after surgical treatment of adjacent lesions of the jaws. MATERIALS AND METHODS: The records of 341 biopsies submitted to the institute's histopathology laboratory were reviewed to include cases that met the inclusion criteria. About 84 biopsies collected from patients during surgical enucleation of lesions in proximity to healthy vital teeth were included of which 22 patients were recalled. Adjacent teeth were examined clinically and radiographically to assess their pulpal and periapical status after at least 8 months of follow-up. RESULTS: There were 7 different pathological lesions diagnosed histologically. The follow-up period ranged between 8 and 72 months; 12 cases (54.6%) have developed pulpal necrosis for at least one tooth after surgical enucleation of the lesion. The other 10 cases (45.4%) showed normal responses to sensibility testing for all the teeth adjacent to the lesion. Ten out of the 12 cases (83%) that underwent pulpal necrosis were associated with odontogenic cysts, whereas the remaining 2 were associated with periapical granuloma and fibrous dysplasia. CONCLUSION: Pulp necrosis is high in vital teeth associated with lesions without pulpal involvement. These teeth may benefit from root canal treatment prior to surgical enucleation of the lesion, which may prevent impaired healing or recurrence of infection. CLINICAL SIGNIFICANCE: Careful treatment planning and thorough discussion should take place between the surgeons, endodontists, and patients prior to executing the treatment. The patient should be aware that there is a possibility that they may need root canal treatment as a preventative measure to enhance the chances of healing following the surgical procedures and in case the patients opted not to perform root canal treatment beforehand, close follow-up in the future should take place to monitor the vitality of the teeth in the follow-up visits.

Nociceptors regulate osteoimmune transcriptomic response to infection.

Osteoimmune diseases, such as apical periodontitis, are prevalent, often painful, inflammatory conditions resulting in bone loss and reduced quality of life. There is growing evidence that the nociceptive fibers densely innervating affected tissues regulate disease progression; therefore, we hypothesized that nociceptors regulate the transcriptomic profile of the periapical osteolytic lesion in a mouse model of apical periodontitis. Male control and nociceptor-ablated mice underwent pulp exposures, and after 0, 7, or 14 days, total RNA from periapical tissues was submitted for sequencing and bioinformatic analysis. Pulp exposure triggers the differential expression of hundreds of genes over the course of infection. At 14 days post pulp exposure, 422 genes, including Tnf, Il1a, and Il1b, were differentially expressed between nociceptor-ablated and control mice with greater enrichment of biological processes related to inflammation in nociceptor-ablated mice. Nociceptor ablation regulates the transcriptomic profile of periapical lesions in a mouse model of apical periodontitis, shifting the gene expression profile to a greater enrichment of inflammatory genes, suggesting nociceptors play a role in the kinetics of the immune response. This newly uncovered neuro-immune axis and its mechanisms in apical periodontitis can be an important therapeutic target for the treatment of this prevalent disease.

A Novel Approach for Orthodontic Extrusion Prior to Intentional Replantation: A Case Report.

AIM: This case report aimed to present a novel surgical technique involving orthodontics luxation of the offended tooth using miniscrew prior to performing intentional replantation (IR) to remove an extruded separated instrument that injured the inferior alveolar nerve (IAN). BACKGROUND: Intentional replantation is a dental procedure that involves extracting a tooth, managing the root canal, and then reinserting the tooth back into its socket. This procedure is typically used as a last resort when other treatment options have failed or are not possible. Intentional replantation can be successful in preserving the tooth and preventing tooth loss, but it is important to note that there are risks involved. Maintaining the viability of the periodontal ligament (PDL) is a pivotal step to achieve a favorable outcome. CASE DESCRIPTION: A 15-year-old female patient came to the clinic complaining of electric-like pain in the left mandibular posterior area that radiated to the left ear and sometimes caused a headache. Upon clinical and radiographic evaluation, extruded endodontic file from the mesial root of the left first molar that penetrated the IAN canal was noticed. Nonsurgical root canal retreatment was performed, which failed to retrieve the separated file. Orthodontics luxation of the offended tooth was done 2 weeks before the surgical intervention using a miniscrew to induce PDL inflammation, which increased the tooth mobility and PDL volume, facilitating the atraumatic extraction and reduced the risk of complications, such as root resorption and ankylosis. Then, IR was performed, and the extruded file was successfully retrieved. Three months follow-up showed complete recovery of the endodontics-related IAN injury symptoms. Preapical radiographic evaluation and cone-beam computed tomography scan showed complete healing of the periapical radiolucency/area of low density and complete formation of the PDL space and lamina dura around the resected roots. CONCLUSION: This novel approach using a miniscrew suggests a noninvasive technique that minimizes the damage to the offended tooth surrounding tissues as well as minimizing the morbidity of the adjacent teeth and the vital anatomical structures. CLINICAL SIGNIFICANCE: Multidisciplinary comprehensive preplanning of complicated cases is essential to maximize treatment efficiency. The orthodontic extrusion facilitates the extraction process that helps in preserving the PDL, and ultimately increases the survivability of the teeth. How to cite this article: Alharbi MA, Alghamdi BA, Alswajy WA, et al. A Novel Approach for Orthodontic Extrusion Prior to Intentional Replantation: A Case Report. J Contemp Dent Pract 2023;24(11):895-901.

Trigeminal neurons control immune-bone cell interaction and metabolism in apical periodontitis.

Apical periodontitis (AP) is an inflammatory disease occurring following tooth infection with distinct osteolytic activity. Despite increasing evidence that sensory neurons participate in regulation of non-neuronal cells, their role in the development of AP is largely unknown. We hypothesized that trigeminal ganglia (TG) Nav1.8+ nociceptors regulate bone metabolism changes in response to AP. A selective ablation of nociceptive neurons in Nav1.8Cre/Diphtheria toxin A (DTA)Lox mouse line was used to evaluate the development and progression of AP using murine model of infection-induced AP. Ablation of Nav1.8+ nociceptors had earlier progression of AP with larger osteolytic lesions. Immunohistochemical and RNAscope analyses demonstrated greater number of macrophages, T-cells, osteoclast and osteoblast precursors and an increased RANKL:OPG ratio at earlier time points among Nav1.8Cre/ DTALox mice. There was an increased expression of IL-1α and IL-6 within lesions of nociceptor-ablated mice. Further, co-culture experiments demonstrated that TG neurons promoted osteoblast mineralization and inhibited osteoclastic function. The findings suggest that TG Nav1.8+ neurons contribute to modulation of the AP development by delaying the influx of immune cells, promoting osteoblastic differentiation, and decreasing osteoclastic activities. This newly uncovered mechanism could become a therapeutic strategy for the treatment of AP and minimize the persistence of osteolytic lesions in refractory cases.

Interexaminer Agreement in the Radiologic Identification of Apical Periodontitis/Rarefying Osteitis in the National Dental Practice-Based Research Network PREDICT Endodontic Study.

INTRODUCTION: Periapical images are routinely made in endodontics to support diagnosis and treatment decisions, but conventional imaging may not readily demonstrate inflammatory changes. This study aims to quantify disagreement in the radiologic interpretation of apical periodontitis/rarefying osteitis between 2 expert examiners and to determine if differences exist based on anatomic location. METHODS: We used 1717 pretreatment periapical images made before orthograde endodontic treatment as part of the Predicting Outcomes of Root Canal Treatment (PREDICT) study conducted within the National Dental Practice-Based Research Network. Periapical changes were assessed independently by 2 board-certified specialists, an oral and maxillofacial radiologist and an endodontist, blinded to other clinical information. If the examiners disagreed about whether a diagnosis of apical periodontitis/rarefying osteitis was justified, an adjudication was made by a third examiner. RESULTS: The overall prevalence of this radiologic diagnosis in the periapical images was 55%, and interexaminer agreement measured with the Cohen kappa statistic was calculated to be 0.56 (95% confidence interval, 0.52-0.60). Diagnostic disagreements between the 2 examiners occurred for 377 teeth (22%), with disagreements more frequent for jaw location (P = .038) and tooth type (P = .021). Differences between root number (P = .058) and jaw location and tooth groups (P = .069) were found not to be statistically significant. CONCLUSIONS: The variability of diagnostic disagreements across anatomic location and tooth type may reflect the inability of periapical images to reveal bone changes masked by the complexity and density of overlying anatomic structures, a limitation that could potentially be overcome with the use of 3-dimensional imaging.

Clinical Outcomes of Immature Teeth Treated with Regenerative Endodontic Procedures-A San Antonio Study.

INTRODUCTION: Factors that influence clinical outcomes for regenerative endodontic procedures (REPs) are unknown. This retrospective study aimed to assess tooth healing, root development, pulp vitality, and esthetics post-REPs and categorize them into clinician- and patient-centered outcomes. Furthermore, this study identified significant predictors affecting such outcomes. METHODS: Immature permanent teeth diagnosed with pulp necrosis treated with REPs between 2008 and 2018 with a minimum of 1-year follow-up were included. Outcomes included success and survival rates, changes in root development using 2-dimensional radiographic root area (RRA) and 3-dimensional measurements, pulp vitality, and tooth discoloration. Predictor variables of success included age, sex, etiology of pulp necrosis (PN), type of medicament, sodium hypochlorite (NaOCl) concentration, type of biomaterial used over the blood clot, and preoperative apical diagnosis. Statistical analyses included Cox proportional hazard analyses and generalized regression models. RESULTS: Fifty-one teeth with an average of 2.1 years of follow-up satisfied the criteria. The survival rate was 92%. The success rate was 84.3% with age, etiology of PN, type of medicament, and NaOCl concentration being significant predictors of failure. Root development occurred in 91.4% of cases with age, sex, etiology of PN, type of medicament, NaOCl concentration, and apical diagnosis being significant predictors for RRA change. Positive pulp sensibility responses were associated with greater RRA change, and, finally, the type of biomaterial was a significant predictor for tooth discoloration after treatment. CONCLUSIONS: REPs provide a high survival rate. Patient and clinical factors may affect outcomes, and this knowledge may help to define the criteria for optimal treatment planning of REPs.

Neurotrophic Proteins in Dentin and Their Effect on Trigeminal Sensory Neurons.

INTRODUCTION: A plethora of bioactive molecules present during tooth formation become sequestered in the mineralized dentin matrix and can be released into the pulp tissue after demineralization from carious lesions. However, neurotrophic factors are differentially expressed and secreted during various stages of odontogenesis. Thus, the aims of this study were (1) to investigate their presence and relative abundance in crown and root dentin and (2) to evaluate the bioactivity of dentin-derived proteins on neuronal cells. METHODS: Dentin matrix proteins (DMPs) were isolated from matched roots and crowns of extracted healthy human third molars. The total protein amount as well as the concentration of growth factors and neurotrophic proteins were quantified. The impact on neuritogenesis was determined with mouse trigeminal neurons in vitro and by a hydrogel implant model in vivo. Transient receptor potential cation channel subfamily V member 1 (TRPV1) sensitization of DMP-conditioned neurons was evaluated by single-cell calcium imaging. RESULTS: The relative concentration of neurotrophic molecules revealed that nerve growth factor is the most abundant neurotrophin with 3-fold increased expression in radicular dentin. Similarly, brain-derived neurotrophic factor and neurotrophin 3 are more abundant in radicular than coronal dentin. Conversely, glial cell line-derived neurotrophic factor is more abundant in coronal dentin, whereas neurotrophin 4 is equally distributed. Dentin matrix proteins promoted neurite outgrowth in vitro and axonal targeting in vivo, with a greater effect observed by radicular dentin extracts. Furthermore, DMPs sensitized TRPV1 responses in mouse trigeminal neurons with greater activity seen with extracts from root dentin. CONCLUSIONS: Neurotrophic factors are differentially distributed between coronal and radicular dentin with different effects of dentin-derived proteins on axonal growth and targeting as well as the sensitization of TRPV1. Thus, extracellular proteins from the dentin matrix are likely involved in neurogenic responses to caries and could be exploited in clinical regenerative endodontics to promote reinnervation and enhance tissue regeneration.

Expression of Neurotrophic Factors in Human Dentin and Their Regulation of Trigeminal Neurite Outgrowth.

INTRODUCTION: Neurotrophic factors play a significant role in the innervation of the pulp-dentin complex during and after organogenesis. There have been numerous bioactive molecules identified in the dentin extracellular matrix; however, the expression of neurotrophic factors in the dentin matrix and their biological activity are largely unknown. The purpose of this study was to characterize the relative expression of neurotrophic factors in human dentin matrix proteins (DMPs) and their effect on neurite outgrowth of trigeminal (TG) neurons. METHODS: Dentin was powdered in liquid nitrogen from noncarious human third molar teeth. DMPs were solubilized through an EDTA extraction method, dialyzed, and lyophilized until use. The relative expression of nerve growth factor, brain-derived neurotrophic factor, glial cell-line derived neurotrophic factor, neurotrophin 3, and neurotrophin 4/5 was determined by the enzyme-linked immunosorbent assay. Rat TG neurons were cultured and exposed to different concentrations of DMPs (1-105 ng/mL) or vehicle, and a quantitative neurite outgrowth assay was performed. RESULTS: Human DMPs contained all of the tested neurotrophic factors, with glial cell-line derived neurotrophic factor and neurotrophin 4/5 found at the highest levels. DMPs were able to promote the neurite outgrowth of rat TG neurons at an optimum concentration of 10-102 ng/mL, whereas the effect was partially inhibited at higher concentrations (>103 ng/mL). CONCLUSIONS: The human dentin extracellular matrix is a rich reservoir for neurotrophic factors that are key components for neuronal homeostasis, differentiation, and regeneration. These data suggest that neurotrophins in DMPs could play an important role as signaling molecules for the innervation of the pulp-dentin complex during the processes of tooth formation, repair, and regeneration.

Comprehensive Characterization of 2 Immature Teeth Treated with Regenerative Endodontic Procedures.

INTRODUCTION: Regeneration of the pulp-dentin complex is the penultimate goal of regenerative endodontic procedures (REPs). Histological outcomes have demonstrated reparative tissue formation in human teeth extracted post-REPs. However, lack of accurate characterization has precluded identification of the true nature of tissues formed post-REP. METHODS: Here, we present 2 case reports of tooth #29 and #9 treated with REPs and demonstrate their clinical, radiographic, and histological outcomes. RESULTS: Clinical outcomes revealed healing of apical periodontitis in both teeth and re-establishment of vitality responses in tooth #29. Moreover, radiographic assessments using 2D and 3D-volumetric analyses demonstrate considerable increase in root development for both teeth. Further, histological outcomes evaluated using Hematoxylin and Eosin and immunohistochemical staining demonstrates presence of vascular and lymphatic structures as well as immune cell markers indicative of regeneration of an immunocompetent pulp. Lastly, examination of hard tissue deposition shows dentin-like tissue in parts of tooth #29 demonstrating for the first time, regeneration of a pulp-dentin complex post-REP. CONCLUSIONS: Collectively, this is the first study demonstrating recapitulation of several tissues commonly found as part of a pulp-dentin complex in teeth treated with REPs.

Evaluation of a Commercially Available Hyaluronic Acid Hydrogel (Restylane) as Injectable Scaffold for Dental Pulp Regeneration: An In Vitro Evaluation.

INTRODUCTION: Regenerative endodontic procedures (REPs) are viable alternatives for treating immature teeth, yet these procedures do not predictably lead to pulp-dentin regeneration. A true bioengineering approach for dental pulp regeneration requires the incorporation of a scaffold conducive with the regeneration of the pulp-dentin complex. Several materials have been proposed as scaffolds for REPs; nonetheless, the majority are not eligible for immediate clinical chairside use. Thus, the aim of this study was to evaluate Restylane, a Food and Drug Administration-approved hyaluronic acid-based gel, as possible scaffold for REPs. METHODS: Stem cells of the apical papilla (SCAP) were cultured either alone or in mixtures with either Restylane or Matrigel scaffolds. Groups were cultured in basal culture medium for 6, 24, and 72 hours, and cell viability was assessed. For the mineralizing differentiation experiments, groups were cultured in differentiation medium either for 7 days and processed for alkaline phosphatase activity or for 14 days and processed for gene expression by using quantitative reverse-transcription polymerase chain reaction. SCAP in basal medium served as control. RESULTS: Cell encapsulation in either Restylane or Matrigel demonstrated reduced cell viability compared with control. Nonetheless, cell viability significantly increased in the Restylane group in the course of 3 days, whereas it decreased significantly in the Matrigel group. Restylane promoted significantly greater alkaline phosphatase activity and upregulation of dentin sialophosphoprotein, dentin matrix acidic phosphoprotein-1, and matrix extracellular phosphoglycoprotein, compared with control. CONCLUSIONS: A Food and Drug Administration-approved hyaluronic acid-based injectable gel promoted SCAP survival, mineralization, and differentiation into an odontoblastic phenotype and may be a promising scaffold material for REPs.

Capsaicin-sensitive Innervation Modulates the Development of Apical Periodontitis.

INTRODUCTION: Nociceptive neurons play a critical role in the detection of stimuli evoking actual or potential tissue injury. In addition, they are involved in neurogenic inflammation by the peripheral release of neuropeptides such as calcitonin gene-related peptide (CGRP). The dental pulp and periradicular tissues are innervated by capsaicin-sensitive neurons known to release CGRP. However, the role of these capsaicin-sensitive neurons in the development of apical periodontitis is largely unknown. The aim of this study was to evaluate the contribution of peptidergic neurons to the development of apical periodontitis. METHODS: Neonatal Sprague-Dawley rats were injected with vehicle (control group) or a single subcutaneous capsaicin dose to cause the selective ablation of peptidergic neurons (neonatal capsaicin group). Ablation of capsaicin-sensitive neurons was verified with confocal microscopy, capsaicin-induced eye-wipe nocifensive behavior test, and by measurement of immunoreactive CGRP levels in the dental pulp. Five weeks after ablation, standardized pulp exposures were made in the mandibular left first molars. Mandibles were harvested at 7, 14, 21, and 28 days after pulp exposure and imaged with micro-computed tomography (µCT) to quantify apical lesion volume. Data were analyzed by using 2-way ANOVA analysis with Bonferroni post hoc test. RESULTS: Rats in the control group displayed a robust capsaicin-induced nocifensive behavior, which was nearly abolished in the neonatal capsaicin group. In addition, the neonatal capsaicin group showed a significant depletion of susceptible neurons and CGRP in the dental pulp compared with control. Importantly, micro-computed tomography analysis showed larger periradicular lesions at 7 and 14 days after pulp exposure in the neonatal capsaicin group when compared with control. CONCLUSIONS: Results identify a protective role for capsaicin-sensitive neurons in the initial phase of apical periodontitis. Thus, interventions or disorders that alter activity of capsaicin-sensitive fibers are likely to alter the development of apical periodontitis.

Photodynamic therapy as an adjunctive to scaling and root planing in treatment of chronic periodontitis in smokers.

OBJECTIVE: To compare photodynamic therapy (PDT) as an adjunctive treatment of chronic periodontitis with scaling and root planing (Sc/Rp) in smokers. METHODS: This is a split-mouth, single-masked randomized controlled clinical trial conducted at the Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia between May 2010 and March 2011. Fifty-four teeth with probing depth of ≥5mm at one or more periodontal sites in 20 smokers diagnosed with moderate to severe chronic periodontitis were selected. In each patient, at least one tooth was randomly assigned to Sc/Rp plus PDT (test group) and the contra-lateral tooth was assigned to Sc/Rp only (control). Plaque index (PI), bleeding on probing (BOP), probing depth (PD), recession and clinical attachment level (CAL) were recorded at baseline and 3 months after the periodontal treatment. Descriptive statistics and Wilcoxon signed ranked test were used for data analysis. RESULTS: There was a statistically significant improvement in PD, CAL, BOP, and PI after periodontal treatment in both groups. No statistically significant differences between the 2 groups in any of the periodontal parameters were found at baseline (p>0.05), but a statistically significant greater reduction in PD (p=0.028) and CAL (p=0.044) in the test compared to the control group was found at the 3-month follow up. CONCLUSION: Photodynamic therapy might have an additional benefit to scaling and root planing when treating smokers affected with periodontitis.

Self reported halitosis in relation to glycated hemoglobin level in diabetic patients.

OBJECTIVE: This study was conducted to examine the relationship between the glycated hemoglobin level (HbA1c) and halitosis status among diabetic patients affected with periodontitis and to examine if there is a relationship between halitosis and different periodontal parameters. METHODS AND MATERIALS: Consecutive type 2 diabetic patients were recruited from patients presented for treatment at a University hospital. Age, gender and smoking were recorded. A structured questionnaire on patients' perception of their oral health, halitosis and diabetes severity and control was completed. Peripheral blood samples were obtained and analyzed for HbA1c levels. In addition, periodontal clinical parameters including probing depth, clinical attachment level, bleeding on probing and plaque scores were recorded. RESULTS: A total of 38 type 2 diabetic patients were selected. The mean age was 52.1 (±8.8) years. Sixteen subjects (42.1%) reported halitosis. Of these, 62.5% were females, and only one subject was a current smoker. The mean levels of HbA1c were significantly different between those with and without halitosis, mean 9.6 (±2) and 8.2 (±1.6), respectively (p=0.03). No significant differences were found in the mean periodontal parameters between those with and without halitosis. CONCLUSION: The results of this study suggest an association between halitosis and increased levels of HbA1c. Further studies are needed to explain the nature of this association.