Endodontic medicine: connections between apical periodontitis and systemic diseases

Gut microbiota dysbiosis links chronic apical periodontitis to liver fibrosis in nonalcoholic fatty liver disease: Insights from a mouse model

AIM

In this study, we investigated the systemic implications of chronic apical periodontitis (CAP). CAP may contribute to the nonalcoholic fatty liver disease (NAFLD) progression through the gut microbiota and its metabolites, which are related to the degree of fibrosis.

METHODOLOGY

Sixteen 7-week-old male apolipoprotein E knockout (apoE-/-) mice were randomly divided into two groups: the CAP and Con groups. A CAP model was established by sealing the first- and second-maxillary molars with bacterium-containing cotton balls. Apical lesions were evaluated by micro-CT. Histological evaluations of NAFLD were performed using second harmonic generation/two-photon excitation fluorescence (SHG/TPEF) assays. Additionally, we comprehensively analyzed the gut microbiota using 16S rRNA gene sequencing and explored metabolic profiles by liquid chromatography-mass spectrometry (LC-MS). Immunofluorescence analysis was used to examine the impact of CAP on tight junction proteins and mucin expression. Transcriptome assays have elucidated gene expression alterations in liver tissues.

RESULTS

Micro-CT scans revealed an evident periapical bone loss in the CAP group, and the total collagen percentage was increased (Con, 0.0361 ± 0.00510%, CAP, 0.0589 ± 0.00731%, p < .05). 16S rRNA sequencing revealed reduced diversity and distinct taxonomic enrichment in the CAP group. Metabolomic assessments revealed that differentially enriched metabolites, including D-galactosamine, were enriched and that 16-hydroxyhexadecanoic acid and 3-methylindole were depleted in the CAP group. Immunofluorescence analyses revealed disruptions in tight junction proteins and mucin production, indicating intestinal barrier integrity disruption. Liver transcriptome analysis revealed upregulation of Lpin-1 expression in the CAP group.

CONCLUSION

This study provides comprehensive evidence of the systemic effects of CAP on liver fibrosis in NAFLD patients by elucidating alterations in the gut microbiota composition and metabolism.

Multi-model deep learning approach for segmentation of teeth and periapical lesions on pantomographs

INTRODUCTION

The fields of medicine and dentistry are beginning to integrate artificial intelligence (AI) in diagnostics. This may reduce subjectivity and improve the accuracy of diagnoses and treatment planning. Current evidence on pathosis detection on pantomographs (PGs) indicates the presence or absence of disease in the entire radiographic image, with little evidence of the relation of periapical pathosis to the causative tooth.

OBJECTIVE

To develop a deep learning (DL) AI model for the segmentation of periapical pathosis and its relation to teeth on PGs.

METHOD

250 PGs were manually annotated by subject experts to lay down the ground truth for training AI algorithms on the segmentation of periapical pathosis. Two approaches were used for lesion detection: Multi-models 1 and 2, using U-net and Mask RCNN algorithms, respectively. The resulting segmented lesions generated on the testing data set were superimposed with results of teeth segmentation and numbering algorithms trained separately to relate lesions to causative teeth. Hence, both multi-model approaches related periapical pathosis to the causative teeth on PGs.

RESULTS

The performance metrics of lesion segmentation carried out by U-net are as follows: Accuracy = 98.1%, precision = 84.5%, re-call = 80.3%, F-1 score = 82.2%, dice index = 75.2%, and Intersection over Union = 67.6%. Mask RCNN carried out lesion segmentation with an accuracy of 46.7%, precision of 80.6%, recall of 55%, and F-1 score of 63.1%.

CONCLUSION

In this study, the multi-model approach successfully related periapical pathosis to the causative tooth on PGs. However, U-net outperformed Mask RCNN in the tasks performed, suggesting that U-net will remain the standard for medical image segmentation tasks. Further training of the models on other findings and an increased number of images will lead to the automation of the detection of common radiographic findings in the dental diagnostic workflow.

Interplay between diabetes mellitus and periodontal/pulpal-periapical diseases

This longevity of life expectancy has indirectly led to an increase in the number of chronic diseases such as periodontitis, apical periodontitis (AP), and diabetes mellitus (DM) in the aging society, thus affecting people's quality of life. There is an interaction between periodontitis/AP and DM with a two-way relationship. Although type 1 and 2 diabetes (T1DM, T2DM) have different etiologies, glycemic control may affect the infection, inflammation and tissue healing of periodontitis and AP. Non-surgical periodontal treatment may influence the glycemic control as shown by decrease of HbA1c level in T2DM patient. However, the effect of periodontal treatment on glycemic control in T1DM and root canal treatment/apical surgery on T1DM and T2DM patients awaits investigation. DM may affect the periodontal and periapical tissues possibly via altered oral microbiota, impairment of neutrophils' activity and host immune responses and cytokine production, induction of oxidative stress etc. While periodontitis associated systemic inflammation and hyperlipidemia is suggested to contribute to the control of T2DM, more intricate studies are necessary to clarify the detailed mechanisms. The interactions between DM (T1DM and T2DM) and periodontitis and AP are therefore reviewed to provide a basis for the treatment of subsequent patients with pulpal/periodontal disease and diabetes. A two-pronged approach of medical and dental treatment is needed for the management of these patients, with emphasis on blood glucose control and improving oral hygiene and periodontal maintenance care, to ensure the best treatment outcome.

Healing of apical periodontitis in type II diabetes mellitus patients: A prospective study

OBJECTIVE

This study aimed to compare the healing of periapical bone between type II diabetes patients and healthy patients after root canal treatment.

SUBJECTS AND METHODS

This study included 26 diabetic patients and the control group with healthy patients matching the diabetic group in age and sex. The study included only teeth with satisfactory coronal restoration. The periapical index system was used to evaluate the periapical status of treated teeth at follow-ups after 6 and 12 months.

RESULTS

Analysis of the results revealed a significantly higher healing rate in the control group compared to the diabetic group only at the 6-month follow-up (66.6 vs. 33.3%; Χ2 = 4.857; p = 0.0275). Analysis of the full-scale PAI index disclosed significantly higher PAI values in the diabetic subjects at 6- and 12-month follow-up. The regression analysis showed that the risk of apical periodontitis persistence increased significantly with female gender (OR = 3.92; 95% CI = 1.04-14.79; p = 0.043), diabetes mellitus (OR = 4.27; 95% CI: 1.18-15.50; p = 0.027) and higher household income (OR = 5.39; 95% CI = 1.33-21.89; p = 0.018).

CONCLUSION

Root canal treatment remains an effective means of conservative treatment in diabetic patients. While the healing is not compromised, regular follow-ups are necessary to monitor the healing process.

High-performing cross-dataset machine learning reveals robust microbiota alteration in secondary apical periodontitis

Multiple research groups have consistently underscored the intricate interplay between the microbiome and apical periodontitis. However, the presence of variability in experimental design and quantitative assessment have added a layer of complexity, making it challenging to comprehensively assess the relationship. Through an unbiased methodological refinement analysis, we re-analyzed 4 microbiota studies including 120 apical samples from infected teeth (with/without root canal treatment), healthy teeth, using meta-analysis and machine learning. With high-performing machine-learning models, we discover disease signatures of related species and enriched metabolic pathways, expanded understanding of apical periodontitis with potential therapeutic implications. Our approach employs uniform computational tools across datasets to leverage statistical power and define a reproducible signal potentially linked to the development of secondary apical periodontitis (SAP).

Expert consensus on endodontic therapy for patients with systemic conditions

The overall health condition of patients significantly affects the diagnosis, treatment, and prognosis of endodontic diseases. A systemic consideration of the patient's overall health along with oral conditions holds the utmost importance in determining the necessity and feasibility of endodontic therapy, as well as selecting appropriate therapeutic approaches. This expert consensus is a collaborative effort by specialists from endodontics and clinical physicians across the nation based on the current clinical evidence, aiming to provide general guidance on clinical procedures, improve patient safety and enhance clinical outcomes of endodontic therapy in patients with compromised overall health.

Evaluating the Diagnostic Accuracy of an AI-Driven Platform for Assessing Endodontic Treatment Outcomes Using Panoramic Radiographs: A Preliminary Study

Background/Objectives: The purpose of this preliminary study was to evaluate the diagnostic performance of an AI-driven platform, Diagnocat (Diagnocat Ltd., San Francisco, CA, USA), for assessing endodontic treatment outcomes using panoramic radiographs (PANs). Materials and Methods: The study included 55 PAN images of 55 patients (15 males and 40 females, aged 12-70) who underwent imaging at a private dental center. All images were acquired using a Hyperion X9 PRO digital cephalometer and were evaluated using Diagnocat, a cloud-based AI platform. The AI system assessed the following endodontic treatment features: filling probability, obturation adequacy, density, overfilling, voids in filling, and short filling. Two human observers independently evaluated the images, and their consensus served as the reference standard. The diagnostic accuracy metrics were calculated. Results: The AI system demonstrated high accuracy (90.72%) and a strong F1 score (95.12%) in detecting the probability of endodontic filling. However, the system showed variable performance in other categories, with lower accuracy metrics and unacceptable F1 scores for short filling and voids in filling assessments (8.33% and 14.29%, respectively). The accuracy for detecting adequate obturation and density was 55.81% and 62.79%, respectively. Conclusions: The AI-based system showed very high accuracy in identifying endodontically treated teeth but exhibited variable diagnostic accuracy for other qualitative features of endodontic treatment.

Nanoarchitectonics-Based Materials as a Promising Strategy in the Treatment of Endodontic Infections

Endodontic infections arise from the interactive activities of microbial communities colonizing in the intricate root canal system. The present study aims to update the latest knowledge of nanomaterials, their antimicrobial mechanisms, and their applications in endodontics. A detailed literature review of the current knowledge of nanomaterials used in endodontic applications was performed using the PubMed database. Antimicrobial nanomaterials with a small size, large specific surface area, and high chemical activity are introduced to act as irrigants, photosensitizer delivery systems, and medicaments, or to modify sealers. The application of nanomaterials in the endodontic field could enhance antimicrobial efficiency, increase dentin tubule penetration, and improve treatment outcomes. This study supports the potential of nanomaterials as a promising strategy in treating endodontic infections.

Evaluation of postoperative pain in endodontic retreatment with apical periodontitis using ozonated 2% chlorhexidine and 0.1% octenidine application: A randomized clinical trial

Introduction

This study aimed to evaluate and compare postoperative pain (PP) in single-visit nonsurgical endodontic retreatment (SV NSER) with 2% chlorhexidine (CHX), 0.1% octenidine (OCT) with or without ozone, and 5.25% sodium hypochlorite (NaOCl).

Materials and Methods

In this randomized, parallel, prospective, double-blind, clinical trial, 132 single-rooted, root-filled teeth with symptomatic apical periodontitis (AP) requiring NSER were allocated into six groups randomly (n = 22/group): 2% CHX with NaOCl (CHXH), 2% Ozonated CHX without NaOCl (OCHX), 2% Ozonated CHX with NaOCl (OCHXH), 0.1% OCT with NaOCl (OCTH), 0.1% Ozonated OCT without NaOCl (OOCT), and 0.1% Ozonated OCT with NaOCl (OOCTH). Standard NSER protocol was followed groups were irrigated with 15 ml of ozonated or nonozonated irrigant (CHX/OCT) for 3-5 min with ultrasonic agitation. PP at baseline, after 6, 12, 24, 48 h, and 7 days was recorded using the Visual Analog Scale (VAS). Logistic regression of predictor variables was compared using the Chi-square test. For group-wise and time-wise comparisons, a two-way analysis of variance followed by the post hoc Bonferroni test was carried out.

Results

None of the patient-related variables in logistic regression obtained a statistically significant (P > 0.05) role in PP. The VAS score after 6 h was OCHX (4.72) > OOCT (4.42) > CHXH (4.23) > OCTH (3.95) > OCHXH (3.42) > OOCTH (3.21). OOCTH and OCHXH groups demonstrated statistically significant reductions in VAS scores at various time intervals (P < 0.05).

Conclusion

SV NSER with ozonated OCT, CHX irrigation, and NaOCl resulted in lesser PP at all time intervals, i.e., 6, 12, 24, 48 h, and 7 days in patients with symptomatic AP.

Endodontic Treatment of Chronic Apical Periodontitis Ameliorates Systemic Inflammation and Restores Impaired Cellular Responses to Insulin in an In Vitro Model

INTRODUCTION

A growing body of research supports an association between periapical inflammation and an increased risk of developing systemic diseases. There is currently no scientific evidence to support a causal effect of inflammation on the onset of insulin resistance (IR) in patients with apical periodontitis (AP). The aim of this in vitro study was to evaluate any association between AP and levels of serum inflammatory factors potentially associated with the onset of IR, and to investigate the effect of root canal treatment (RCT) on these systemic inflammation markers and on the response in vitro to insulin.

METHODS

A total of 27 control subjects and 27 patients with AP were enrolled. Patients with AP underwent RCT and were followed-up 6 and 12 months post-treatment. Enzyme-linked immunosorbent assays were used to evaluate serum levels of proinflammatory cytokines interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF)-α. The response in vitro to insulin was assessed by measuring glucose consumption in a human pancreatic epithelioid carcinoma cell line treated with sera from healthy and AP subjects.

RESULTS

At baseline AP was associated with significant higher levels of IL-1, IL-6, and IL-8 in the serum of untreated (AP) patients vs controls (P < .001). Glucose consumption decreased in pancreatic cells incubated with baseline serum from patients with AP, in a manner proportional to total cytokines amount. Notably, endodontic treatment was associated with reduced levels of cytokines (P < .001) and improved response to insulin in AP group (P < .001).

CONCLUSIONS

Our findings suggest that AP may promote inflammatory-driven IR in an in vitro model, and that RCT may ameliorate inflammatory mediators in vivo and the cellular response to insulin in vitro.

Is there any association between the presence of biomarkers and apical periodontitis? A systematic review

This systematic review aimed to verify whether there is evidence of an association between apical periodontitis and the presence of systemic biomarkers. This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - PRISMA. For this, the acronym PECO was used; population (P) of adult humans exposed (E) to the presence of apical periodontitis, compared (C) to adult humans without apical periodontitis, and the outcome (O) of the presence of biomarkers was observed. The articles were searched in PubMed, Scopus, Web of Science, LILACS, Cochrane Library, OpenGray, and Google Scholar grey databases. Subsequently, studies were excluded based on title, abstract, and full article reading, following the eligibility criteria. The methodological quality of the selected studies was evaluated using the Newcastle-Ottawa qualifier. After exclusion, 656 studies were identified, resulting in 17 final articles that were divided into case-control, cross-sectional, and cohort studies. Eight studies were considered to have a low risk of bias, one had a medium risk of bias, and eight had a high risk of bias. In addition, 12 articles evaluated biomarkers in blood plasma, four evaluated them in saliva, and only one evaluated them in gingival crevicular fluid. The results of these studies indicated an association between apical periodontitis and the systemic presence of biomarkers. These markers are mainly related to inflammation, such as interleukins IL-1, IL-2, and IL-6, oxidative markers, such as nitric oxide and superoxide anions, and immunoglobulins IgG and IgM.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier (CRD42023493959).

Unveiling the oral-gut connection: chronic apical periodontitis accelerates atherosclerosis via gut microbiota dysbiosis and altered metabolites in apoE-/- Mice on a high-fat diet

The aim of this study was to explore the impact of chronic apical periodontitis (CAP) on atherosclerosis in apoE-/- mice fed high-fat diet (HFD). This investigation focused on the gut microbiota, metabolites, and intestinal barrier function to uncover potential links between oral health and cardiovascular disease (CVD). In this study, CAP was shown to exacerbate atherosclerosis in HFD-fed apoE-/- mice, as evidenced by the increase in plaque size and volume in the aortic walls observed via Oil Red O staining. 16S rRNA sequencing revealed significant alterations in the gut microbiota, with harmful bacterial species thriving while beneficial species declining. Metabolomic profiling indicated disruptions in lipid metabolism and primary bile acid synthesis, leading to elevated levels of taurochenodeoxycholic acid (TCDCA), taurocholic acid (TCA), and tauroursodeoxycholic acid (TDCA). These metabolic shifts may contribute to atherosclerosis development. Furthermore, impaired intestinal barrier function, characterized by reduced mucin expression and disrupted tight junction proteins, was observed. The increased intestinal permeability observed was positively correlated with the severity of atherosclerotic lesions, highlighting the importance of the intestinal barrier in cardiovascular health. In conclusion, this research underscores the intricate interplay among oral health, gut microbiota composition, metabolite profiles, and CVD incidence. These findings emphasize the importance of maintaining good oral hygiene as a potential preventive measure against cardiovascular issues, as well as the need for further investigations into the intricate mechanisms linking oral health, gut microbiota, and metabolic pathways in CVD development.

Periapical Lesions in Panoramic Radiography and CBCT Imaging-Assessment of AI's Diagnostic Accuracy

Background/Objectives: Periapical lesions (PLs) are frequently detected in dental radiology. Accurate diagnosis of these lesions is essential for proper treatment planning. Imaging techniques such as orthopantomogram (OPG) and cone-beam CT (CBCT) imaging are used to identify PLs. The aim of this study was to assess the diagnostic accuracy of artificial intelligence (AI) software Diagnocat for PL detection in OPG and CBCT images. Methods: The study included 49 patients, totaling 1223 teeth. Both OPG and CBCT images were analyzed by AI software and by three experienced clinicians. All the images were obtained in one patient cohort, and findings were compared to the consensus of human readers using CBCT. The AI's diagnostic accuracy was compared to a reference method, calculating sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and F1 score. Results: The AI's sensitivity for OPG images was 33.33% with an F1 score of 32.73%. For CBCT images, the AI's sensitivity was 77.78% with an F1 score of 84.00%. The AI's specificity was over 98% for both OPG and CBCT images. Conclusions: The AI demonstrated high sensitivity and high specificity in detecting PLs in CBCT images but lower sensitivity in OPG images.

The Hidden World Within: Microbial Dynamics in Root Canal Systems

Several hundred different microbial taxa have made the oral cavity their home because of their evolution in multiple species communities within the special ecosystem. On the other hand, the dental pulp or internal tissue of the tooth is a connective tissue that is physiologically sterile and where any microbial infiltration is a harmful indication. It causes the pulp tissue to become inflamed, which leads to the death of the pulp and diffuses infection with inflammation to the peri-radicular tissues. Comprehending the biology of biofilms, the microbial makeup, and the host's reaction to infections in the pathobiology of root canal infections has received a lot of attention throughout the last few decades. Such comprehensive knowledge is required to design preventive medicines as well as clinically effective treatment regimens. Surprisingly, clinical approaches have concentrated more on radiographically perfecting channel preparation than on debridement of these intricate root canal systems, despite the clear realization that root canal infections are biofilm mediated. Since the present comprehension of the microbial etiopathogenesis of apical periodontitis highlights the significance of focusing on procedures such as "canal cleaning" and chemo-mechanical disinfection, the exclusive purpose of endodontic therapy is mainly missed while discussing "canal shaping." We thoroughly examine the state of our knowledge of the composition and functional traits of the root canal microbiome in this review. We also go into the difficulties with root canal disinfection and the cutting-edge approaches that try to solve these difficulties. In conclusion, we present essential guidance for prospective research areas, underscoring their significance as crucial considerations in the field of frontiers in oral health.

Association between pulp and periapical disease with type 2 diabetes: A bidirectional Mendelian randomization

AIM

This current Mendelian randomization (MR) study aims to comprehensively explore the potential bidirectional link between pulp and periapical disease (PAP) with type 2 diabetes mellitus (T2DM).

METHODOLOGY

Summary level data of European-based population genome-wide association studies (GWASs) were employed to undertake this MR study. With the selection of single nucleotide polymorphisms (SNPs) as the instrumental variable, the radial inverse-variance weighted (radial IVW) method with modified second-order weights was applied as the primary method. Additionally, a range of sensitivity analyses were conducted to investigate pleiotropy. Results from different sources of outcome were pooled by meta-analysis with the fixed model.

RESULTS

The results of this MR analysis did not suggest a significant impact of pulp and periapical disease on type 2 diabetes (combined OR = 1.04, 95% CI: 1.00-1.07, p = .033) and vice versa (OR = 1.04, 95% CI: 0.96-1.14, p = .329). No significant pleiotropy was detected in the final model after the removal of outliers, demonstrating the reliability of the results in our primary analysis.

CONCLUSIONS

With the limitations inherent in the present MR study, there is no significant evidence in either direction to suggest a causal association between pulp and periapical disease and type 2 diabetes mellitus.

Prevalence of oral infections in chronic kidney disease patients: A cross-sectional study

OBJECTIVES

The purpose of this investigation was to analyze the prevalence of apical periodontitis (AP) and periodontal disease (periodontitis) (PD) in Chronic kidney disease (CKD) patients in relation to their treatment phase.

SUBJECTS AND METHODS

In this cross-sectional study, 188 patients with CKD were divided into two groups: patients without dialysis (WD group, n = 53) and patients on dialysis (DP group, n = 135). Panoramic radiographs were used to diagnose AP. The presence of periodontal disease was evaluated radiographically assessing alveolar bone loss. Student's t-test, chi-squared test, and logistic regression analysis were used to determine the significance of differences between groups.

RESULTS

In the WD group, 55% of patients had at least one tooth with AP, whereas in the DP group 67% had at least one tooth with AP (OR = 2.11; 95% CI = 1.09-4.08; p < 0.05). PD was more prevalent in the DP group (78%) than in the WD group (36%) (OR = 6.26; CI 95% = 3.13-12.52; p < 0.01).

CONCLUSIONS

Oral infections are more prevalent in the advanced stages of CKD. The treatment of PD and AP should be incorporated in the treatment planning of patients with CKD.

High-Fat Diet Influences Dendritic Cells and T-Cell Infiltration in Apical Periodontitis in Mice

INTRODUCTION

Diet-induced metabolic syndrome may influence the progression and healing of apical periodontitis (AP). The aim of this study was to evaluate the inflammatory immune response of dendritic cells (DCs) and T helper (Th) cells in normal versus obese mice with AP.

METHODS

Twenty male C57BL/6 mice were divided into 2 groups: normal chow (NC) and high-fat diet (HFD) for 12 wk. AP was induced in both groups by creating pulp exposure of the right first maxillary molar to the oral environment. Contralateral first molars from each mouse were used as a control. The animal's body mass was recorded on a weekly basis, and they were euthanized after 30 d. The maxillae were removed and processed for micro-computed tomography (micro-CT), histologic analysis, and immunofluorescence staining for DCs (CD11c), Th17 (IL-17A), and T regulatory cells (FOXP3 and IL-10). Different groups were analyzed by Mann-Whitney U test, Student t test, and ordinary 1-way analysis of variance followed by Tukey's multiple comparisons test. The level of significance (α) was set at 0.05.

RESULTS

The HFD group showed larger AP lesions than the NC group from micro-CT analysis. For the NC group, induction of AP significantly increased immune cell infiltration when compared with control. HFD showed increased DCs and Th17 infiltration in the control group without AP. In addition, there was no significant change in the amount of DCs and Th17 in the HFD-AP group when compared with the NC-AP and HFD-control groups.

CONCLUSIONS

HFD resulted in an increased immune cell infiltration in the periapical area without AP. Despite the larger AP lesion observed in HFD-AP than that of NC-AP, the amount of infiltrated inflammatory cells did not differ significantly. The results of this study suggest that the DCs and Th17 inflammatory pathways are affected by HFD in the periapical region, but their contribution toward AP complicated by metabolic syndrome requires further investigation.

Oral Health in Patients with History of Head and Neck Cancer: Complexity and Benefits of a Targeted Oral Healthcare Pathway

PURPOSE OF REVIEW

This work consists in a literature review on the current state of knowledge regarding the oral management of patients with a history of head and neck cancer (HNC), corroborated by clinical cases and illustrated by clear infographic summaries. It aims to provide healthcare professionals with a comprehensive overview of the oral health status of HCN patients.

RECENT FINDINGS

Head and neck cancers (HNCs) represent the seventh most common type of cancer worldwide, with over 660,000 annual new cases. Despite the significant negative impact of HNCs on oral health, patients often receive no or inappropriate oral care while the significant impact of oral pathologies on cancer prognosis is commonly underestimated. This work (i) describes the oral cavity during and after HNC through the prism of care complexity and (ii) highlights several potential key factors that could worsen long-time patients' prognosis and quality of life. By investigating the biological, microbiological, functional, and psychological dimensions of the interrelationships between HNCs and oral health, the authors explored the barriers and benefits of a targeted oral healthcare pathway. This article emphasizes the importance of multidisciplinary care and highlights the need for further research elucidating the intricate relationships between oral health and HNCs, particularly through the microbiota.

Association between apical periodontitis and secondary outcomes of atherosclerotic cardiovascular disease: A case-control study

AIM

To evaluate the association between apical periodontitis (AP) and atherosclerotic cardiovascular disease (ASCDV).

METHODOLOGY

A total of 65 periodontally and systemically healthy patients (age ≥ 40 years) were included in the study. Periapical status was assessed through dental examination and periapical radiographs; 33 subjects had AP (AP+), while 32 acted as control (AP-). Moreover, data regarding their periapical index (PAI) score and the Decayed, Missing, and Filled Teeth (DMFT) index were recorded. All subjects underwent echo-colour Doppler assessment of carotid intima-media thickness (CIMT), carotid plaques, degree of stenosis using the North American Symptomatic Carotid Surgery Trial (NASCET) method, maximum diameter of the abdominal aorta (maximum AA) and common iliac arteries (CIA) diameters. Furthermore, peripheral blood flow was also measured using the ankle-brachial index (ABI). Simple and multiple regression analyses were performed.

RESULTS

Among AP+ patients, 57.58% disclosed at least one sign of subclinical carotid atherosclerosis. Multiple regression analysis identified AP as a significant risk indicator for carotid plaques [OR = 4.87 (1.27, 18.98; p = .021)] and marked carotid intima-media thickenings (OR = 14.58 [1.22, 176.15], p = .035). A significant association was established between AP and other cardiovascular (CV) variables (CIMT, NASCET, and maximum AA). On the contrary, a higher PAI score does not correlate to increased odds of carotid alterations, and the presence of AP did not prove any significant change in CIA and ABI. No significant correlation was established between DMFT and other variables.

CONCLUSIONS

Results from the current study highlight that the presence of AP may be regarded as a risk indicator for ASCVD, with AP being associated with 5-fold increased odds of having carotid plaques and 15-fold increased odds of having marked carotid intima-media thickenings. Further studies should be conducted in order to verify whether AP treatment could be beneficial for ASCVD signs.

Prevalence of apical periodontitis and non-retention of root-filled teeth in hypertensive patients: Systematic review and meta-analysis

BACKGROUND

Several studies have suggested a relationship between AP, as well as the loss of root-filled teeth (RFT), and hypertension (HTN).

OBJECTIVES

The aims of this systematic review and meta-analysis were to investigate the prevalence of AP, and non-retention of RFT, in hypertensive patients.

METHODS

A search was performed in PubMed/MEDLINE, Web of Science, Scopus and EMBASE. The inclusion criteria established were studies published until February 2023, comparing hypertensive subjects with controls, assessing the prevalence of AP and/or providing data on the prevalence of non-retained RFT. Meta-analysis was performed using the RevMan (analyst) tool to determine the pooled prevalence of AP and loss of RFT. Risk of bias was assessed using the Cochrane Risk-of-Bias tool. The quality of evidence was assessed by GRADE.

RESULTS

The search strategy identified 454 articles, and only eight met the inclusion criteria. Six studies had analysed the association between AP and HTN and two studies had analysed the association between non-retention of RFT and HTN. Meta-analysis showed and overall OR = 1.71 (95% CI = 0.92-3.16; p = .09) for the prevalence of AP among patients with HTN. The prevalence of non-retention of RFT among patients with HTN has an overall OR = 1.78 (95% CI = 1.60-1.98; p = .000001). The risk of bias in the individual studies was low or moderate, and the quality of the overall evidence has shown a level of certainty very low.

DISCUSSION

There is no association between the prevalence of AP and HTN. In addition, hypertensive patients have significantly increased odds of losing RFT. Given the high prevalence of hypertension, it is very common to perform root canal treatments on hypertensive patients. It is imperative to communicate this heightened risk to patients and recommend periodic monitoring of oral health and hypertension, paying special attention to this subset of patients.

REGISTRATION

PROSPERO CRD42022302385.

Biological response to endodontic treatment in one versus two-visit: a systematic review and meta-analysis of animal studies

OBJECTIVES

To perform a systematic review of animal studies that compared the histopathological characteristics between teeth with apical periodontitis after endodontic treatment in one or two visits.

MATERIALS AND METHODS

This systematic review was registered on the International Prospective Register of Systematic Reviews (PROSPERO) - CRD42022340849. Studies were collected from PubMed/MEDLINE, LILACS, EMBASE, Livivo, SciELO, Web of Science, Scopus, and Cochrane Library and manual and gray literature searches. Animal studies that evaluated histological characteristics after endodontic treatment of teeth with apical periodontitis in one or two visits were included. Risk of bias analysis of the included studies was performed using the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) tool. Data synthesis of the included studies with quantitative data was performed, and meta-analysis was conducted with the Comprehensive Meta-Analysis software, using the random effects model and odds ratio (OR).

RESULTS

Eighteen studies met the inclusion criteria (Kappa = 0.891). Meta-analyses indicated values in inflammatory infiltrate intensity with effect size of 5.5% (95% CI: 0.020-0.148; p < 0.001), periodontal ligament thickness: 25.6% (95% CI: 0.134-0.487; p < 0.001), dentin resorption: 13% (95% CI: 0.015-1.141; p = 0.066), cementum resorption: 7.1% (95% CI: 0.015-0.325; p = 0.001), bone resorption: 1.4% (95% CI: 0.002-0.130; p < 0.001), mineralized tissue resorption: 42.8% (95% CI: 0.110-1.671; p = 0.222), biological apical sealing: 13.1% (95% CI: 0.055-0.314; p < 0.001), and presence of microorganisms: 10.3% (95% CI: 0.014-0.747; p = 0.025).

CONCLUSIONS

When considering animal studies, the two-visit endodontic treatment, using calcium hydroxide-based intracanal medication, resulted in better biological repair characteristics.

CLINICAL RELEVANCE

A two-visit endodontic treatment with calcium hydroxide-based intracanal medication yields superior histopathological outcomes.

Experimental apical periodontitis alters salivary biochemical composition and induces local redox state disturbances in the salivary glands of male rats

OBJECTIVES

The objective was to evaluate the effects of experimental apical periodontitis on the inflammatory, functional, biochemical, and redox parameters of the parotid and submandibular glands in rats.

MATERIALS AND METHODS

Twenty 12-week-old male Wistar rats were randomly divided into two groups (n = 10): a control group and apical periodontitis group. After 28 days, the saliva was collected for salivary flow rate and biochemistry composition. Both glands were sampled for quantification of the tumor necrosis factor-alpha (TNF-α) and biochemical analyses of redox state.

RESULTS

TNF-α concentrations were higher in both salivary glands adjacent to the periapical lesions in animals with apical periodontitis and also compared to the control group. The apical periodontitis group increased the salivary amylase, chloride, potassium, calcium, and phosphate. The total oxidant capacity increased in the parotid gland adjacent to the periapical lesions in the same rat and compared to the control group. Conversely, the total antioxidant capacity of the parotid glands on both sides in the apical periodontitis group was lower than that in the control group. Furthermore, glutathione peroxidase activity increased in the submandibular gland adjacent to the apical periodontitis group compared to the control group.

CONCLUSIONS

Experimental apical periodontitis alters salivary biochemical composition, in addition to increasing inflammatory marker and inducing local disturbances in the redox state in the parotid and submandibular glands of male rats.

CLINICAL RELEVANCE

Apical periodontitis could exacerbate the decline in oral health by triggering dysfunction in the salivary glands.

Impact of chronic diseases on the periapical health of endodontically treated teeth: A systematic review and meta-analysis

Systemic diseases affecting the immune system can influence the body's response time to endodontic treatment, potentially necessitating a longer duration for the complete resolution of existing infections when compared to healthy controls. This systematic review aims to evaluate the association between the presence of chronic diseases and periapical status after endodontic treatment through a systematic and comprehensive assessment of existing literature on this topic. The search strategy covered seven electronic databases and grey literature, encompassing articles published until October 2023. Two reviewers independently assessed potentially eligible studies based on the following criteria: Included were studies involving populations exposed to pre-existing chronic diseases who underwent endodontic treatment in permanent teeth. These studies evaluated periapical health status, making comparisons with healthy individuals. There were no language or publication date restrictions. Additionally, two reviewers independently extracted data regarding the characteristics of the included studies. The risk of bias was assessed using the Joanna Briggs Institute Critical Assessment Checklist. Meta-analysis was conducted using random effects models. The certainty of evidence was assessed using the GRADE tool. Twenty-three studies were included in the synthesis. Patients with diabetes were found to have about half the odds of having periapical health compared to non-diabetic patients (OR = 0.46; 95% CI = 0.30-0.70%; I2 = 58%) in teeth that underwent endodontic treatment. On the other hand, other systemic diseases like HIV, cardiovascular disease, and rheumatoid arthritis did not demonstrate significant differences concerning the outcome. In conclusion, diabetic patients showed a lower likelihood of maintaining periapical health. Conversely, patients with HIV, cardiovascular disease, and rheumatoid arthritis did not exhibit significant differences, although the existing evidence is still considered limited. It is crucial to manage these patients in a multidisciplinary manner to provide appropriate care for this population.

Impact of Smoking on the Healing of Apical Periodontitis after Nonsurgical Endodontic Treatment

OBJECTIVES

 The aim of this prospective study was to compare the healing of periapical bone between smokers and nonsmokers after root canal therapy. The effects of duration and intensity of smoking on the healing rate of apical periodontitis were analyzed.

MATERIALS AND METHODS

 Fifty-five smokers were included in this study. The control group consisted of healthy nonsmokers who matched the smoker group in age and sex. Only teeth with a favorable periodontal prognosis and adequate coronal restoration were included in the study. The periapical status of treated teeth was assessed using the periapical index system at follow-ups after 6 and 12 months.

STATISTICAL ANALYSIS

 The chi-squared test and Mann-Whitney U test were used to assess the changes in periapical index score at baseline and in subsequent time intervals between the two groups examining dichotomized and ordinal data, respectively. Multivariate logistic regression analysis was used to test the association of independent variables age, gender, tooth type, arch type, and smoking index with the outcome variable. The outcome variable was set as the presence versus absence of apical periodontitis.

RESULTS

 The analysis at 12-month follow-up revealed a significantly higher healing rate in control group than in smokers (90.9 vs. 58.2; χ2 = 13.846; p < 0.001). Smokers had significantly higher periapical index scores than the control group (p = 0.024). The multivariate logistic regression analysis demonstrated that an increase in the value of the smoking index significantly increases the risk of apical periodontitis persistence (odds ratio [OR] =7.66; 95% confidence interval [CI]: 2.51-23.28; p < 0.001) for smoking index < 400 and (OR = 9.65; 95% CI: 1.45-64.14; p = 0.019) for smoking index 400 to 799.

CONCLUSION

 The results from this study show a lower rate of apical periodontitis healing in a group of smokers at 1-year follow-up. Delayed periapical healing seems to be associated with the cigarette smoking exposure.

Primary apical periodontitis correlates to elevated levels of interleukin-8 in a Swedish population: A report from the PAROKRANK study

AIM

To explore associations between root filled teeth, primary and secondary apical periodontitis, and levels of inflammatory markers in blood from patients with a first myocardial infarction and matched controls.

METHODOLOGY

Between May 2010 and February 2014, 805 patients with a first myocardial infarction and 805 controls, matched for sex, age, and postal code area, were recruited to the multicentre case-control study PAROKRANK (periodontitis and its relation to coronary artery disease). All participants underwent a physical and oral examination, as well as blood sampling. Using panoramic radiography, root filled teeth, primary apical periodontitis, and secondary apical periodontitis were assessed by three independent observers. Blood samples were analysed with enzyme-linked immunosorbent assay method for the following inflammatory markers: interleukin-1β (IL-1β), IL-2, IL-6, IL-8, IL-12p70, tumour necrosis factor-α, and high-sensitivity C-reactive protein (hsCRP). Additionally, white blood cell count and plasma-fibrinogen were analysed. Associations between endodontic variables and the levels of inflammatory markers were statistically analysed with Mann-Whitney U-test and Spearman correlation, adjusted for confounding effects of baseline factors (sex, age, myocardial infarction, current smoking, diabetes, family history of cardiovascular disease, education, marital status, and periodontal disease).

RESULTS

Mean age of the cohort was 62 years, and 81% were males. Root fillings were present in 8.4% of the 39 978 examined teeth and were associated with higher levels of hsCRP, fibrinogen, and leukocyte count, but lower levels of IL-2 and IL-12p70. After adjusting for confounders, root filled teeth remained associated with higher levels of fibrinogen, but lower levels of IL-1β, IL-2, IL-6, and IL-12p70. Primary apical periodontitis was found in 1.2% of non-root filled teeth and associated with higher levels of IL-8 (correlation 0.06, p = .025). Secondary apical periodontitis was found in 29.6% of root filled teeth but did not relate to the levels of any of the inflammatory markers.

CONCLUSIONS

This study supports the notion that inflammation at the periapex is more than a local process and that systemic influences cannot be disregarded. Whether the observed alterations in plasma levels of inflammatory markers have any dismal effects on systemic health is presently unknown but, considering the present results, in demand of further investigation.

Successful endodontic treatment reduces serum levels of cardiovascular disease risk biomarkers-high-sensitivity C-reactive protein, asymmetric dimethylarginine, and matrix metalloprotease-2

AIM

To investigate serum biomarkers of inflammation 2 years following non-surgical root canal re-treatment (Re-RCT) and peri-apical surgery (PS). The results were correlated with signs and symptoms, treatment outcome, metabolic syndrome factors, infection with severe acute respiratory syndrome coronavirus 2 SARS-CoV-2 (COVID-19) infection and COVID-19 vaccination.

METHODOLOGY

Subjects from our previous study were recalled for 2 years post-treatment follow-up. Changes to the patient's history (medical, dental, social) were noted. Periapical health of the treated teeth was examined both clinically and radiographically. Blood pressure, fasting HbA1C and low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides and total cholesterol (TC) levels were measured. Serum inflammatory marker levels were assayed using a Bio-Rad Bio-Plex 200 analyser and values at different time points within the same group were compared using a Wilcoxon signed-rank test and differences between groups with a Mann-Whitney test. Linear associations were tested using Pearson's correlations.

RESULTS

The recall percentage at 2 years was 56.9% (n = 37), with a 100% radiographic success rate using periapical radiographs. In total, 21 cases (56.8%) were completely healed, and 16 cases (43.2%) were healing. Higher matrix metalloprotease 2 (MMP2) levels were present in the healing group compared to the healed group. Serum levels of high-sensitivity C-reactive protein (hs-CRP), asymmetric dimethylarginine (ADMA) and MMP-2 were significantly reduced (p ≤ .001) whereas other biomarkers showed significant increases at 2 year compared to pre-operative levels, while FGF-23 and ICAM-1 were not significantly increased. HbA1C (p = .015), TC (p = .003), LDL (p = .003) and HDL (p = .003) reduced significantly at 2 years post-treatment compared to their preoperative levels. COVID infection showed a significant association with MMP-9 (p = .048).

CONCLUSIONS

hs-CRP, ADMA and MMP-2 can be regarded as prognostic biomarkers of successful Re-RCT and PS as they reduced at 2 year recall in cases which showed evidence of clinical and radiographic success. The successful treatment of chronic apical periodontitis is correlated with improvements in metabolic syndrome indicators, better glycemic control, and reduction at 2 year of some systemic inflammatory markers which are related to risks of cardiovascular disease events.

Effects of Nd: YAG laser on tumour necrosis factor-alpha, interleukin-1beta and interferon-gamma levels in teeth with apical periodontitis: A clinical study

This study aimed to evaluate the levels of tumour necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and interferon-gamma (IFN-γ) with asymptomatic apical periodontitis (AP). A total of 60 participants were randomly divided into two groups: the conventional irrigation (control) and the Nd: YAG laser irradiation. The interstitial fluids were obtained after root canal cleaning (day 0) and 1 week later (day 7). The TNF-α, IL-1β and IFN-γ levels were assayed using the enzyme-linked immunosorbent assay. The Mann-Whitney U, continuity correction chi-square, Pearson chi-square and Fisher exact tests were used. An increased level of cytokines on day 7 in the control group was observed, without statistically significant differences (p > 0.05). All cytokine levels decreased over time in the laser group. Only the IL-1β level showed a significant difference (p < 0.05). Nd: YAG irradiation has a positive effect on decreasing the proinflammatory cytokine level and may help to control infection in teeth with AP.

Demographics, smoking status, and systemic health factors associated with apical periodontitis in a Brazilian rural population: a cross-sectional study

OBJECTIVE

To determine whether the systemic diseases diabetes mellitus (DM) and arterial hypertension (AH), and smoking status are associated with apical periodontitis (AP) in a representative rural population.

MATERIALS AND METHODS

Cross-sectional study using a representative sample of individuals obtained from a population-based epidemiological survey carried out in the rural area of the city of Rosário do Sul, RS, Brazil, from March 2015 to May 2016. Data were collected through structured questionnaires and clinical examination. Binary logistic regression analysis was performed to identify variables independently associated with AP.

RESULTS

Of the 584 individuals included in the study, 353 (60.4%) had AP. The presence of AP was independently associated with age ≥ 40 years (odds ratio [OR] = 1.867, 95% confidence interval [CI]: 1.193-2.923, p = 0.006), non-white ethnicity (OR = 1.509, 95% CI: 1.029-2.115, p = 0.035), active or former smoker (OR = 2.087, 95% CI: 1.241-3.510, p = 0.006) and DM or prediabetes (OR = 1.676, 95% CI: 1.150-2.443, p = 0.007).

CONCLUSION

The study identified significant associations between AP and demographics, smoking status, and systemic disease in a Brazilian rural population.

CLINICAL RELEVANCE

The study emphasized the significance of comprehending and managing associated factors in preventing and treating AP.

Periapical Lesions Associated with Demographic Variables, Dental Conditions, Systemic Diseases, and Habits

AIM AND BACKGROUND

The aim of this study was to analyze the prevalence of periapical lesions and possible associations with demographic, dental conditions, systemic diseases, and habit variables in patients from a private Brazilian university.

MATERIALS AND METHODS

Data from 452 patients of both sexes, aged 18-78 years, from a Brazilian university were evaluated. Panoramic radiographs were analyzed, and the presence of periapical lesions was recorded. In these cases, the dental condition was assessed for the presence or absence of endodontic treatment. Medical records provide information related to general health (diabetes, cardiovascular diseases, altered cholesterol, autoimmune diseases, gallstones, or kidney stones) and habits (smoking or alcoholism). The data were descriptively analyzed, and then logistic regression and the Wald test were performed in Stata/SE v.14.1.

RESULTS

A rate of 58.4% of participants were women, and the mean age was 36.4 (±14.6) years. Periapical lesions prevailed in 193 (42.7%) patients, and 281 (72.4%) teeth were not previously endodontically treated. Mandibular first molars (19%) and men (48.9%) were the most affected. The adjusted model showed that the age group of 26-45 years was 5 times more likely [odds ratio (OR) = 5.01; 95% confidence interval (CI): 2.85-8.82] to have lesions than those aged ≤25 years. Participants aged above 46 years were 19.1 times more prone (OR = 19.1; 95% CI: 10.2-36.0) to morbidity than younger ones (≤25 years).

CONCLUSION

The studied sample showed that periapical lesions were more prevalent in males, in mandibular molars, and without prior endodontic treatment. There was no observed association between periapical lesions and comorbidities or habits; however, a significant correlation occurred with advancing age.

CLINICAL SIGNIFICANCE

Comorbidities and habits were not associated with the presence of periapical lesions. However, aging has been identified as a significant risk factor for the development of periapical lesions. This finding is clinically relevant as it highlights the importance of monitoring and maintaining oral health in patients with advanced age. How to cite this article: dos Santos VC, de Oliveira Kublitski PM, Marques da Silva B, et al. Periapical Lesions Associated with Demographic Variables, Dental Conditions, Systemic Diseases, and Habits. J Contemp Dent Pract 2023;24(11):864-870.

Association of Apical Periodontitis with Different Stages of Chronic Kidney Disease Measured by Glomerular Filtration Rate and Systemic Markers: An Observational Study

INTRODUCTION

The aim of this study was to assess the prevalence and severity of apical periodontitis (AP) in subjects with different stages of chronic kidney disease (CKD) and its association with systemic markers.

METHODS

In this cross-sectional study, 105 patients with CKD (n = 35 each in the early, predialysis, and hemodialysis groups) and 105 healthy controls were included. The prevalence, number of teeth with AP (endodontic burden [EB]), and the severity of AP were recorded. High- sensitivity C-reactive protein, blood urea, and serum creatinine levels were also recorded. Logistic regression was applied to determine the possible association between CKD and AP in the study population, and linear regression was performed to predict the effect of AP on systemic markers in CKD patients.

RESULTS

AP in at least 1 tooth was found in 75.2% of CKD patients and 40.9% of the controls (P < .05). CKD patients were 4 times more likely to have AP than controls (P < .05; odds ratio = 3.954; 95% confidence interval, 2.09-7.45). EB and the severity of AP were also significantly higher in CKD patients than the healthy controls (P < .05). Although higher values of EB and severe AP were observed with the progression of disease, the difference was not significant. The severity of AP was significantly associated with an increase in serum creatinine, blood urea, and a decrease in estimated glomerular filtration rate (P < .05) in CKD patients.

CONCLUSIONS

AP was significantly more prevalent in the CKD group. The association between the severity of AP and CKD markers suggests that AP could possibly alter the progression of CKD. However, these findings do not establish a cause-and-effect relationship.

The Link Between Apical Periodontitis and Gastrointestinal Diseases-A Systematic Review

INTRODUCTION

This systematic review aimed to examine a potential link between apical periodontitis (AP) and gastrointestinal diseases (GIDs).

METHODS

The protocol of the review has been registered in PROSPERO (CRD42022330771). The following engines were used with the aim of searching for relevant literature: PubMed, Web of Science, Scopus, Cochrane Central Register of Controlled Trials, and grey literature, from inception to May 2022. There were no language restrictions included. Study selection, data collection, and synthesis have been performed by 2 independent reviewers. For the purpose of estimating the quality of studies, the Newcastle-Ottawa Scale was used.

RESULTS

Four matched case control studies, as well as a single longitudinal cohort study were included in the final review. These were published between 2012 and 2017, and comprised 537 participants whose age range was 18 to 87 years. It was not possible to perform a meta-analysis due to different study designs and evaluated outcomes of included studies. Except for one study that was categorized as "Good," overall, for 4 out of 5 studies the quality was assessed as "Fair".

CONCLUSIONS

This review highlighted sparse knowledge present in the literature concerned with the association between AP and GIDs. Available evidence reveals a potential link between impaired endodontic status, assessed by the number of root-filled teeth with periapical radiolucency, and GIDs. More research is needed to ascertain this association.

The role of systemic statins in the inception and healing of apical periodontitis: a systematic review

OBJECTIVES

Statins are a category of medications widely used to reduce plasma LDL-cholesterol levels, that also possess antibacterial, anti-inflammatory, and immunomodulatory action. The aim of this systematic review was to explore the effects of systemic statins therapy on the development and treatment of apical periodontitis (AP) on humans and animals.

MATERIAL AND METHODS

Three electronic databases (PubMed, Web of Science, and Scopus) and grey literature were searched from their inception until February, 20 2023 (PROSPERO CRD42021246231). For the quality assessment and risk of bias, different guidelines were used according to the typology of the studies considered (Animal Research Reporting of In Vivo Experiments, Newcastle-Ottawa Quality Assessment Form for Cohort Studies, Systematic Review Centre for Laboratory animal Experimentation Risk of Bias tool and Tool to assess risk of bias in cohort studies of CLARITY Group).

RESULTS

Seven hundred eleven records were screened, and six articles were included for this qualitative review. The eligible studies showed a moderate overall quality and risk of bias. Human patients in treatment with statins exhibited a higher healing rate of AP following root canal treatment. In experimental animal models, statins had a beneficial effect on the development of AP.

CONCLUSIONS

Despite the limited number of studies and considering that most of them are on animals, our findings suggest that systemically administered statins make a positive contribution to prevent the development and help healing of AP.

CLINICAL RELEVANCE

There is an increased evidence that a pharmacologic adjunct to endodontic treatment may be considered to enhance healing of AP. Among other medications, statins seem to have a positive impact on the disease.

The bioceramic sealer iRoot SP promotes osteogenic differentiation of human stem cells from apical papilla via miR-141-3p/SPAG9/MAPK signalling pathway

AIM

The premixed bioceramic sealer iRoot SP that is widely used clinically has been reported to kill bacterial biofilms and promote osteogenic differentiation of human stem cells from the apical papilla (hSCAPs). Although miR-141-3p has been substantiated to be involved in the osteogenic process, the underlying mechanisms remain unclear. The aim of this study was to investigate the role of miR-141-3p in osteogenic differentiation and underlying mechanisms of iRoot SP-treated hSCAPs.

METHODOLOGY

hSCAPs were extracted from tissue blocks with enzyme digestion and identified by using immunofluorescence, flow cytometry and alizarin red staining. The mRNA expression level of miR-141-3p in hSCPAs after culture with iRoot SP was examined by quantitative real-time PCR (qRT-PCR) assay. SPAG9 was identified as a downstream target gene of miR-141-3p by dual-luciferase report assay. Alkaline phosphatase (ALP) staining and activity detection, alizarin red staining, calcium concentration assay, qRT-PCR and western blot were used to estimate osteogenic differentiation ability and involved protein expression levels of the osteogenic makers and signalling pathway-related factors in iRoot SP-treated hSCAPs. Data were analysed by one-way anova and post hoc Tukey's test to determine any statistical differences between the experimental groups and the control group. p < .05 was considered statistically significant.

RESULTS

Expression of miR-141-3p was reduced in iRoot SP-treated hSCAPs with the increased exposure time up to 7 days, and the western blot and qRT-PCR results revealed that the osteogenic markers osteocalcin (OCN), osterix (OSX), runt-related transcription factor 2 (RUNX2) and dentin sialophosphoprotein (DSPP) were inversely correlated with miR-141-3p. The negative regulatory relationship between miR-141-3p and SPAG9/ mitogen-activated protein kinases (MAPK) signalling axis was validated in this in vitro experiments.

CONCLUSIONS

The bioceramic sealer iRoot SP promoted osteogenic differentiation of hSCAPs by inhibiting miR-141-3p following down-regulated SPAG9 expression, and activated MAPK pathway. These findings proposed a novel therapeutic impact of bioceramic sealer iRoot SP inducing bone regeneration in refractory periapical periodontitis.

Machine learning techniques for periodontitis and dental caries detection: A narrative review

OBJECTIVES

In recent years, periodontitis, and dental caries have become common in humans and need to be diagnosed in the early stage to prevent severe complications and tooth loss. These dental issues are diagnosed by visual inspection, measuring pocket probing depth, and radiographs findings from experienced dentists. Though a glut of machine learning (ML) algorithms has been proposed for the automated detection of periodontitis, and dental caries, determining which ML techniques are suitable for clinical practice remains under debate. This review aims to identify the research challenges by analyzing the limitations of current methods and how to address these to obtain robust systems suitable for clinical use or point-of-care testing.

METHODS

An extensive search of the literature published from 2015 to 2022 written in English, related to the subject of study was sought by searching the electronic databases: PubMed, Institute of Electrical and Electronics Engineers (IEEE) Xplore, and ScienceDirect.

RESULTS

The initial electronic search yielded 1743 titles, and 55 studies were eventually included based on the selection criteria adopted in this review. Studies selected were on ML applications for the automatic detection of periodontitis and dental caries and related dental issues: Apical lessons, Periodontal bone loss, and Vertical root fracture.

CONCLUSION

While most of the ML-based studies use radiograph images for the detection of periodontitis and dental caries, few pieces of the literature revealed that good diagnostic accuracy could be achieved by training the ML model even with mobile photos representing the images of dental issues. Nowadays smartphones are used in every sector for different applications. Training the ML model with as many images of dental issues captured by the smartphone can achieve good accuracy, reduce the cost of clinical diagnosis, and provide user interaction.

Efficacy of imaging techniques for the diagnosis of apical periodontitis: A systematic review

BACKGROUND

Apical periodontitis (AP) is a chronic inflammatory response of microbial aetiology. Pathological changes associated with AP may not be visible on radiographic images and may linger without causing any symptoms. Clinicians rely mostly on clinical examination and imaging techniques to establish a diagnosis.

OBJECTIVES

The aim of this review was to answer the following question using the PICO format: In the adult human permanent dentition (P), what is the efficacy of diagnostic imaging of the periapical tissues (I) using histopathology as a reference standard (C) in the diagnosis of apical periodontitis, in terms of diagnostic accuracy (O).

METHODS

MEDLINE, EMBASE, Scopus and Cochrane Library were searched for English articles published through October 2021. At least two independent reviewers evaluated the study design, imaging modality used, histopathological assessment, outcome measures, results and conclusions for each article. The risk of bias was assessed using the Quality Assessment Tool for Diagnostic Accuracy Studies-2.

RESULTS

The initial search strategy identified 544 articles. Seven articles were included for analysis in the final review, all of which involved tissue samples obtained from cadavers. No clinical studies were identified that met the eligibility criteria. A consistently low sensitivity score and negative predictive value were reported for periapical radiography, especially in comparison to CBCT, which scored highly. Both modalities achieved high scores for specificity and positive predictive value. Diagnostic accuracy of CBCT was lower for root-filled teeth in comparison to non-root-filled teeth.

DISCUSSION

Assessment of the periapical tissues using periapical radiographs was shown to have a low to moderate agreement with the histopathological assessment. CBCT was reported to be more accurate than PR and demonstrated a good agreement with histopathology, especially for non-root-filled teeth.

CONCLUSIONS

This review identified a need for greater standardization in methodology and reporting, and as the findings are based on cadaver studies, their clinical relevance must be interpreted with caution.

REGISTRATION

PROSPERO (CRD42021272147).

Endodontic Tissue Regeneration: A Review for Tissue Engineers and Dentists

The paradigm shift in the endodontic field from replacement toward regenerative therapies has witnessed the ever-growing research in tissue engineering and regenerative medicine targeting pulp-dentin complex in the past few years. Abundant literature on the subject that has been produced, however, is scattered over diverse areas of knowledge. Moreover, the terminology and concepts are not always consensual, reflecting the range of research fields addressing this subject, from endodontics to biology, genetics, and engineering, among others. This fact triggered some misinterpretations, mainly when the denominations of different approaches were used as synonyms. The evaluation of results is not precise, leading to biased conjectures. Therefore, this literature review aims to conceptualize the commonly used terminology, summarize the main research areas on pulp regeneration, identify future trends, and ultimately clarify whether we are really on the edge of a paradigm shift in contemporary endodontics toward pulp regeneration.

Modulation of blood redox status by the progression of induced apical periodontitis in rats

This study aimed to investigate if apical periodontitis in different periods changes systemic levels of the antioxidant and pro-oxidant parameters in Wistar rats. Twenty-four rats were randomly allocated into healthy animals, apical periodontitis at 14 days (AP14) and apical periodontitis at 28 days (AP28). The first mandibular molars were accessed in the AP groups, and the pulp chamber was exposed to the oral environment, inducing the apical lesion. After 14 and 28 days, the animals were anesthetized, euthanized, and hemimandibles were collected for micro-computed tomography (micro-CT) analysis to measure lesion volume, bone volume (BV), percent of bone to total tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular space (Tb.Sp). A histological examination of the remaining bone was also performed. Finally, blood samples were collected for oxidative biochemistry analysis, investigating glutathione (GSH), Trolox equivalent antioxidant capacity (TEAC), and lipid peroxidation (TBARS). The lesion volume was greater at 28 than at 14 days, as shown by micro-CT. AP14 and AP28 had decreased BV and Tb.Th, but only AP28 showed a reduction in BV/TV. Tb.N and Tb. Sp were increased in apical periodontitis at 28 days. In the histopathological analysis, AP14 had focal regions of moderate mononuclear inflammatory infiltrate, and AP28 had an intense inflammatory infiltrate with bacterial colonies. In the biochemical evaluation, GSH, TEAC, and TBARS were increased after 14 days. However, GSH returned to control levels, TEAC was similar to AP14, and TBARS increased significantly after 28 days. Therefore, the oxidative biochemistry response was modulated according to the progression of periapical damage. After 14 days, the organism could still react to the injury. However, at 28 days, the antioxidant response decreased, associated with an increase in TBARS.

Machine Learning to Predict Apical Lesions: A Cross-Sectional and Model Development Study

(1) Background: We aimed to identify factors associated with the presence of apical lesions (AL) in panoramic radiographs and to evaluate the predictive value of the identified factors. (2) Methodology: Panoramic radiographs from 1071 patients (age: 11-93 a, mean: 50.6 a ± 19.7 a) with 27,532 teeth were included. Each radiograph was independently assessed by five experienced dentists for AL. A range of shallow machine learning algorithms (logistic regression, k-nearest neighbor, decision tree, random forest, support vector machine, adaptive and gradient boosting) were employed to identify factors at both the patient and tooth level associated with AL and to predict AL. (3) Results: AL were detected in 522 patients (48.7%) and 1133 teeth (4.1%), whereas males showed a significantly higher prevalence than females (52.5%/44.8%; p < 0.05). Logistic regression found that an existing root canal treatment was the most important risk factor (adjusted Odds Ratio 16.89; 95% CI: 13.98-20.41), followed by the tooth type 'molar' (2.54; 2.1-3.08) and the restoration with a crown (2.1; 1.67-2.63). Associations between factors and AL were stronger and accuracy higher when using fewer complex models like decision tree (F1 score: 0.9 (0.89-0.9)). (4) Conclusions: The presence of AL was higher in root-canal treated teeth, those with crowns and molars. More complex machine learning models did not outperform less-complex ones.

Evaluation of an artificial intelligence system for the diagnosis of apical periodontitis on digital panoramic images

Aims

The aim of the present study was to evaluate the effectiveness of an artificial intelligence (AI) system in the detection of roots with apical periodontitis (AP) on digital panoramic radiographs.

Materials and Methods

Three hundred and six panoramic radiographs containing 400 roots with AP (an equal number for both jaws) were used to test the diagnostic performance of an AI system. Panoramic radiographs of the patients were selected with the terms 'apical lesion' and 'apical periodontitis' from the archive and then with the agreement of two oral and maxillofacial radiologists. The radiologists also carried out the grouping and determination of the lesion borders. A deep learning (DL) model was built and the diagnostic performance of the model was evaluated by using recall, precision, and F measure.

Results

The recall, precision, and F-measure scores were 0.98, 0.56, and 0.71, respectively. While the number of roots with AP detected correctly in the mandible was 169 of 200 roots, it was only 56 of 200 roots in the maxilla. Only four roots without AP were incorrectly identified as those with AP.

Conclusions

The DL method developed for the automatic detection of AP on digital panoramic radiographs showed high recall, precision, and F measure values for the mandible, but low values for the maxilla, especially for the widened periodontal ligament (PL)/uncertain AP.

Inflammatory profile of apical periodontitis exacerbated by cigarette smoke inhalation: Histological and immunohistochemical analysis in rats

AIM

The aim of this study was to evaluate the effects of cigarette smoke inhalation (CSI) on inflammation, pro-inflammatory mediators and haematological parameters in rats with induced apical periodontitis (AP).

METHODOLOGY

Thirty-two 3-month-old male Wistar rats were divided into four experimental groups (n = 8): C-Control; S-rats with CSI; AP-rats with AP; and SAP-rats with CSI + AP. Animals in groups S and SAP inhaled cigarette smoke by remaining inside a smoking chamber for 8 min, three times daily, for 50 days. After 20 days of smoke inhalation, animals in AP and SAP groups had the pulps of the lower right first molar exposed to oral environment for 30 days to induce AP. In these subsequent 30 days, animals in group S and SAP continued with CSI. On Day 50, animals were euthanized and mandibles were histologically processed to assess inflammatory infiltrate, immunohistochemical interleukins (IL-1β, IL-6 and TNF-α), and blood samples collected for laboratory analysis. The Mann-Whitney test was performed for non-parametric data and the pairwise analyses of Student's t-test for parametric data, with a significance level of p < .050.

RESULTS

Inflammatory infiltrate was moderate in AP group and more severe in the SAP (p = .010). The interleukins IL-6, IL-1β and TNF-α were higher in SAP group (p < .001) when compared to the AP group. A greater number of red blood cells (p = .010), haemoglobin (p = .007) and neutrophils (p = .014) were observed in the SAP group in comparison with the AP group.

CONCLUSION

Cigarette smoke inhalation induced a more severe inflammatory infiltrate, with increased levels of pro-inflammatory cytokines and changes in haematological parameters in rats with induced AP. Thus, CSI aggravated AP, exacerbating the inflammatory response.

Next-generation biomaterials for dental pulp tissue immunomodulation

OBJECTIVES

The current standard for treating irreversibly damaged dental pulp is root canal therapy, which involves complete removal and debridement of the pulp space and filling with an inert biomaterial. A regenerative approach to treating diseased dental pulp may allow for complete healing of the native tooth structure and enhance the long-term outcome of once-necrotic teeth. The aim of this paper is, therefore, to highlight the current state of dental pulp tissue engineering and immunomodulatory biomaterials properties, identifying exciting opportunities for their synergy in developing next-generation biomaterials-driven technologies.

METHODS

An overview of the inflammatory process focusing on immune responses of the dental pulp, followed by periapical and periodontal tissue inflammation are elaborated. Then, the most recent advances in treating infection-induced inflammatory oral diseases, focusing on biocompatible materials with immunomodulatory properties are discussed. Of note, we highlight some of the most used modifications in biomaterials' surface, or content/drug incorporation focused on immunomodulation based on an extensive literature search over the last decade.

RESULTS

We provide the readers with a critical summary of recent advances in immunomodulation related to pulpal, periapical, and periodontal diseases while bringing light to tissue engineering strategies focusing on healing and regenerating multiple tissue types.

SIGNIFICANCE

Significant advances have been made in developing biomaterials that take advantage of the host's immune system to guide a specific regenerative outcome. Biomaterials that efficiently and predictably modulate cells in the dental pulp complex hold significant clinical promise for improving standards of care compared to endodontic root canal therapy.

Berberine regulates bone metabolism in apical periodontitis by remodelling the extracellular matrix

OBJECTIVES

The objectives of this study were to explore the role and related mechanism of berberine in repairing bone destruction in apical periodontics (AP).

MATERIALS AND METHODS

AP was established in 14 of 21 male Wistar rats (four weeks of age; 70-80 g) for 3 weeks. The canals were cleaned and administered berberine (2 mg/ml; n = 7) or calcium hydroxide (100 mg/ml; control; n = 7), followed by glass ionomer cement sealing. After 3 weeks, specimen collection followed by micro-computed tomography (μ-CT) and histological staining was performed, including haematoxylin and eosin staining, Masson's trichrome staining, tartrate-resistant acid phosphatase staining, immunohistochemistry and immunofluorescence histochemistry.

RESULTS

μ-CT showed that AP lesion volume reduced in the berberine group. Histopathology showed that berberine decreased the activity and number of osteoclasts but increased the expression of proteins related to osteoblast differentiation, including alkaline phosphatase and osterix. The immune cell, T cell, dendritic cell and macrophage counts were significantly decreased in the berberine group. In the berberine group, the expression of extracellular matrix-degraded proteases, metalloproteinases, was decreased; however, that of extracellular matrix-stable proteases, lysyl oxidases, was increased.

CONCLUSIONS

Berberine controlled the inflammatory response and regulated bone metabolism in AP by reducing metalloproteinase expression and increasing lysyl oxidases expression.

Impact of systemic health on treatment outcomes in endodontics

BACKGROUND

The healing of periapical lesions after root canal treatment (RCT) is not the result of the curative action of the treatment. The process of healing begins with inflammation, and is resolved by the clearance of the immunogen that induces the immune response. Then, the periapical tissue itself carries out the healing of the periapical lesion, by repair or by a combination of repair and regeneration, depending on the host's reparative response working properly. The ultimate objective of RCT is to achieve wound healing by removing the source of bacterial antigens and toxins, allowing chronic inflammatory tissue to become reparative tissue. Some systemic conditions increase the susceptibility of the host to infection or impair the tissue reparative response, maintaining the inflammatory process and periapical bone resorption after RCT. This can cause the failure of RCT and even the need for extraction of the affected tooth.

OBJECTIVE

To analyse the scientific literature on the possible influence of systemic conditions on the treatment outcomes in endodontics, as well as to discuss the biological mechanisms that may be involved.

METHODS

The search was carried out in PubMed, SCOPUS and EMBASE. The inclusion criteria established were original scientific articles reporting data about some systemic condition in relation to treatment outcomes in endodontics, including clinical studies and studies carried out in animal models.

RESULTS

Systemic factors (age, nutrition, stress, hormones, smoking habits), and systemic diseases, such as diabetes, cardiovascular diseases, osteoporosis, HIV infection, inflammatory bowel disease, and others, can influence or interfere in the repair of periapical tissues after RCT.

DISCUSSION

Some of these systemic diseases can alter bone turnover and fibroblast function, preventing or delaying periapical wound healing. Others can alter the microvasculature, reducing nutrients and oxygen supply to periapical tissues. As a result, these systemic conditions can decrease the success rate of RCT and provoke incomplete wound healing (typically granulomatous tissue formation) in the periapical region.

CONCLUSIONS

The results of this narrative review show worse success rate of RCT, with higher percentage of postoperative radiolucent periapical lesions and higher proportion of non-retained teeth (RFT), associated with several systemic conditions, such as smoking habits and diabetes.

Deep Learning for Detection of Periapical Radiolucent Lesions: A Systematic Review and Meta-analysis of Diagnostic Test Accuracy

INTRODUCTION

The aim of this systematic review and meta-analysis was to investigate the overall accuracy of deep learning models in detecting periapical (PA) radiolucent lesions in dental radiographs, when compared to expert clinicians.

METHODS

Electronic databases of Medline (via PubMed), Embase (via Ovid), Scopus, Google Scholar, and arXiv were searched. Quality of eligible studies was assessed by using Quality Assessment and Diagnostic Accuracy Tool-2. Quantitative analyses were conducted using hierarchical logistic regression for meta-analyses on diagnostic accuracy. Subgroup analyses on different image modalities (PA radiographs, panoramic radiographs, and cone beam computed tomographic images) and on different deep learning tasks (classification, segmentation, object detection) were conducted. Certainty of evidence was assessed by using Grading of Recommendations Assessment, Development, and Evaluation system.

RESULTS

A total of 932 studies were screened. Eighteen studies were included in the systematic review, out of which 6 studies were selected for quantitative analyses. Six studies had low risk of bias. Twelve studies had risk of bias. Pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of included studies (all image modalities; all tasks) were 0.925 (95% confidence interval [CI], 0.862-0.960), 0.852 (95% CI, 0.810-0.885), 6.261 (95% CI, 4.717-8.311), 0.087 (95% CI, 0.045-0.168), and 71.692 (95% CI, 29.957-171.565), respectively. No publication bias was detected (Egger's test, P = .82). Grading of Recommendations Assessment, Development and Evaluationshowed a "high" certainty of evidence for the studies included in the meta-analyses.

CONCLUSION

Compared to expert clinicians, deep learning showed highly accurate results in detecting PA radiolucent lesions in dental radiographs. Most studies had risk of bias. There was a lack of prospective studies.

Effect of endodontic treatment on clinical outcome in type 2 diabetic patients with apical periodontitis

Background

Previous research has demonstrated that poor controlled diabetic showed higher prevalence of AP compared to well-controlled patients and endodontic treatment may improve metabolic control of patients with diabetes. The purpose of this trial was to clinically assess the effects of endodontic treatment on glycemic control in patients with type 2 diabetes mellitus (T2DM) and apical periodontitis (AP).

Study design

For present trial, AP + T2DM with patients insulin injection (Group1, G1,n = 65), AP + T2DM patients with hypoglycaemic agents (Group2, G2, n = 82), and AP patients without DM (Group3, G3, n = 86) were enrolled. After demographic characteristics and clinical examination were achieved, root canal treatment (RCT) was performed for each patient. Subjects were followed up at 2-week, 3- and 6-month. At each visit, blood samples were taken and clinical laboratory studies were performed. At 6-month follow-up, Periapical Index (PAI) score was used to assess the periapical status.

Results

A total of 237 subjects who met the including criteria were allocated in three groups and 223 subjects (94.1%) completed the treatments and the follow-up assessments. After treatment, taking PAI into consideration, both groups showed significant improvement of AP in each group (P < 0.05). Patients in G3 had a continued significant lower concentration of fasting plasma glucose (FPG) levels at follow-up (P < 0.05). A continued reduction of hemoglobin glycation (HbA1c) was observed in most of time points (P < 0.05). Throughout the trial, there are also significant changes in inflammatory factors in short-term.

Conclusion

Endodontic therapy improved AP healing, glycemic control and systemic inflammation in patients with T2DM and/or AP in each group. However, a continued reduction in inflammatory factors and decreasing of HbA1c in short-term could not be observed in this trial.

The expression of cyclic GMP-AMP synthase in human apical periodontitis: A laboratory investigation

AIM

As a key DNA sensor, cyclic GMP-AMP synthase (cGAS) has emerged as a major mediator of innate immunity and inflammation. Human apical periodontitis has yet to be studied for the presence of cGAS. This investigation was conducted to determine if cGAS is involved in the pathological process of human apical periodontitis.

METHODOLOGY

Sixty four human periapical lesions, comprising 20 periapical granulomas and 44 radicular cysts, were employed in this investigation. Healthy gingiva (n = 6), dental pulp (n = 3), and apical papilla (n = 3) were used as control samples. The expression of cGAS in the periapical tissues was discovered using immunohistochemical staining. mRNA-Sequencing and qRT-PCR were utilized to determine the differentially expressed genes (DEGs) associated with DNA-sensing signalling in periapical lesions compared to the healthy control. Immunofluorescence labelling was used to identify the co-expression of cGAS, interleukin-1β, and interleukin-18.

RESULTS

A significantly greater expression level of cGAS was discovered in the periapical lesions, with no significant difference between radicular cysts and periapical granulomas. mRNA-Sequencing analysis and qRT-PCR identified differentially expressed mRNA, such as cGAS and its downstream DEGs, between periapical lesions and healthy control tissues. Immunofluorescence labelling further revealed that cGAS, interleukin-1, and interleukin-18 were co-localized.

CONCLUSIONS

These observations imply that along with the synthesis of interleukin-1 and interleukin-18, cGAS may be involved in the aetiology of apical periodontitis.

Proinflammatory Cytokine Expression in Apical Periodontitis from Diabetic Patients

Diabetes mellitus has been regarded as a condition capable of influencing the evolution of periapical lesions. Therefore, this study evaluated the immunoexpression of IL-1β, TNF-α, and IL-17 in apical periodontitis from type 2 diabetic patients through immunohistochemistry. Twenty-six periapical lesions were selected, and the images obtained through immunohistochemistry reactions were analyzed. The statistical significance was set at p < 0.05. IL-1β expression was considered focal (54%), weak to moderate (38%), and strong (8%) in diabetics, and focal (46%), weak to moderate (31%), and strong (23%), in controls. TNF-α was focal (85%) and weak to moderate (15%) in diabetics, and focal (92%) and weak to moderate (8%), in controls. IL-17 was focal (8%), weak to moderate (46%), and strong (46%) in diabetics, and focal (62%), weak to moderate (8%), and strong (30%), in controls. The quantitative analysis revealed greater expression of IL-17, with a significant difference between IL-17 × IL-1β × TNF-α(p=0.0009) in the diabetic group. The cytokines IL-1β and TNF-α did not express statistical differences between the tested groups. The IL-17 showed higher immunoexpression in the diabetic group (p=0.047), which may suggest higher bone resorption activity in chronic apical periodontitis in this group of patients.

Apical periodontitis and associated factors in a rural population of southern Brazil: a multilevel analysis

OBJECTIVES

This study aims to evaluate the association between apical periodontitis (AP) and sociodemographic/clinical factors in a probability sample of individuals living in a rural area of southern Brazilian.

MATERIALS AND METHODS

A cross-sectional study was conducted involving 584 non-edentulous adult individuals who had undergone a full-mouth radiographic survey. Periapical status was analysed using the periapical index (PAI). Endodontic status was evaluated considering the occurrence of voids in the filling material and the root filling length. Crown status was classified based on the presence of caries, restorations, and prosthetic crowns. Sociodemographic variables, frequency of dental care, and periodontal disease were also registered. The data were analysed using hierarchical multilevel Poisson regression analysis. The multilevel structure was composed of three models: sociodemographic variables, clinical variables, and clinical variables adjusted by sociodemographic variables (α = 5%).

RESULTS

The prevalence of AP in the sample was 60.45%. AP was significantly associated with age, skin colour, schooling, periodontal disease, and frequency of dental care (P < 0.005). Among the 10,396 teeth evaluated, 868 (8.35%) had AP, which was significantly associated with tooth group, dental arch, crown status, and endodontic treatment (P < 0.005).

CONCLUSIONS

The prevalence of AP was high in the population studied. An older age, black/brown skin colour, low level of schooling, infrequent dental care, severe periodontal disease, mandibular teeth, posterior teeth, inadequate crown status, and having undergone endodontic treatment were significantly associated with the outcome. Clinical relevance This study about a rural probability sample reinforces that AP is still a recurrent oral health problem.

Evaluation of Receptor Activator of Nuclear Factor Kappa B Ligand, Osteoprotegerin, Osteopontin, and Tumor Necrosis Factor Alpha on Chronic Apical Periodontitis in Smokers

INTRODUCTION

Smoking can be considered a risk factor for chronic apical periodontitis (CAP). This study compared the immunoexpression of biomarkers receptor activator of nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG), osteopontin (OPN), and tumor necrosis factor alpha (TNF-α) in CAP in smokers and nonsmokers.

METHODS

Twelve smokers and 12 nonsmokers diagnosed with CAP and indicated for tooth extraction were selected. Exclusion factors were teeth with a diagnosis of root fracture, previous endodontic treatment, or endoperiodontal injury, in addition to individuals with systemic diseases, under 18 years of age, users of anti-inflammatory and/or antibiotics in the last 3 months, and drug users. Specimens were processed for histopathologic and immunohistochemical analysis.

RESULTS

Qualitative analysis of RANKL expression showed 66.66% weak/moderate and 33.33% strong in smokers and 100% weak/moderate in nonsmokers. OPG and OPN expressions were 100% negative to focal in the smoker group and 50% negative to focal and 50% weak/moderate in the nonsmoker group. TNF-α was 25% negative to focal and 75% weak/moderate in the smoker group and 33.33% negative to focal and 66.66% weak/moderate in the nonsmoker group. Quantitative analysis of the data using the Mann-Whitney U test showed that there was a significant difference in the immunoexpression of RANKL (P < .05), OPG (P < .05), and OPN (P < .05), but there was no statistical difference in the immunoexpression of TNF-α (P > .05) between the 2 groups.

CONCLUSIONS

These findings suggest that smoking is capable of altering the inflammatory response, influencing the evolution of CAP.