Endodontics and diabetes: association versus causation

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 any the effect of root canal treatment (RCT) on these systemic inflammation markers and restoring 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. ELISAs were used to evaluate plasma serum levels of pro-inflammatory cytokines interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF)-α. The human pancreatic epithelioid carcinoma cell line (PANC-1) was used to assess t The response in vitro to insulin was assessed by measuring glucose consumption in a human pancreatic epithelioid carcinoma cell line (PANC-1) treated with sera from healthy and AP subjects.

RESULTS

At baseline AP was associated with significantly higher levels of IL-1, IL-6, and IL-8 in the serum of untreated (AP) patients with AP vs controls (p<0.001). 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<0.001) and improved response to insulin in AP group (p<0.001).

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.

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 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.

Effect of periodontitis induced by Fusobacterium nucleatum on the microbiota of the gut and surrounding organs

Detection of the oral bacterium Fusobacterium nucleatum in colorectal cancer tissues suggests that periodontitis may alter gut microbiota. The purpose of this study was to analyze the influence and infection route of periodontal inflammation caused by F. nucleatum, and microbiota of the gut and surrounding organs (heart, liver, kidney). Wistar female rats were orally inoculated with F. nucleatum to establish an experimental periodontitis model that was confirmed by X-ray imaging and histopathological analysis. The mandibles, gut, liver, heart, and kidneys were collected from the experimental group at 2, 4, and 8 weeks, and from the uninfected control group at 0 weeks, for DNA extraction for PCR amplification and comprehensive microbiota analysis using the Illumina MiSeq platform. Imaging confirmed the onset of periodontitis at 2 weeks post-inoculation, and histopathology showed inflammatory cell infiltration from 2 to 8 weeks. PCR and comprehensive microbiota analysis showed the presence of F. nucleatum in the heart and liver at 2 weeks, and in the liver at 4 and 8 weeks. There were changes of microbiota of the gut, heart, liver, and kidneys at 4 weeks: namely, decreased Verrucomicrobia and Bacteroidetes, and increased Firmicutes. F. nucleatum induced the onset of periodontitis and infected the heart and liver in rats. As the periodontic lesion progressed, the microbiota of the gut, liver, heart, and kidneys were altered.

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.

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.

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.

Revisiting the role of IL-1 signaling in the development of apical periodontitis

Apical periodontitis (AP) develops as a result of an immune response to pulpal bacterial infection, and various cytokines are involved in the pathogenesis of AP, with Interleukin (IL)-1 being considered a key cytokine. The role of IL-1 in the pathogenesis of AP has been well studied. It is known that IL-1 expression in periapical lesions correlates closely with the development of AP. IL-1 is a potent bone-resorptive cytokine that induces osteoclast formation and activation. Hence, inhibiting its signaling with IL-1 receptor antagonist (IL-1RA) results in a reduction in periapical lesion size. On the other hand, IL-1 is also a central cytokine that combats bacterial infection by activating innate immune responses. Therefore, a complete loss of IL-1 signaling leads to a failure to limit bacterial dissemination and consequently exacerbates AP. In vivo, IL-1 expression is tightly regulated and its signaling is modulated to optimize the immune response. Obesity causes systemic low-grade chronic inflammation and increases the risk of cardiovascular, renal, and other disorders. In experimentally induced AP, obesity significantly increases periapical bone loss, albeit the underlying mechanism remains unclear. Recent technological innovations have enabled more comprehensive and detailed analyses than previously, leading to new insights into the role of IL-1RA in regulating IL-1 signaling, and modulating apical lesion progression in obesity. In this review, we provide a brief overview of the function of IL-1 in AP development, with special emphasis on the latest findings in normal weight and obese states.

The association of dental pulp stones to cardiovascular and renal diseases: A systematic review and meta-analysis

BACKGROUND

Pulp stone (PS) is a dystrophic calcification in the tooth's pulp chamber and was suggested in the literature to be associated with other calcifications in the body. This study aimed to investigate the association of PS to cardiovascular diseases (CVD) and renal stones (RS).

METHODS

Three databases were searched until June 2021 in addition to manual searching of Google Scholar and grey literature. Original studies were only included and critically appraised using an adapted version of the Newcastle-Ottawa scale. The odds ratio (OR) effect measure was calculated using the Mantel-Haenszel statistical test (95% confidence interval [CI]) to investigate the association of PS with CVD and or RS (p-value ˂ 0.05).

RESULTS

The database search identified 4933 studies, and 19 studies were finally included. The risk of bias was low in thirteen studies, moderate in four studies, and high in two studies. The meta-analysis of the moderate-and-low risk of bias studies revealed a significant association between PS and CVD (OR 3.35, 95% CI 1.91-5.89, P < 0.001, I² = 65%), but no association was found between PS and RS. The results also revealed an association between PS and CVD in patients older than 40 (OR 8.78, 95% CI 3.64-21.17, P < 0.001, I² = 0%).

CONCLUSIONS

The current study results showed an association between PS and CVD, but no association was found between PS and RS. PS in patients younger than 40 years, compared to older patients (> 40 years), was associated with CVD.

Periapical and Endodontic Status of Patients with Inflammatory Bowel Disease: Age- and Sex- matched Case-control Study

AIM

Crohn's disease (CD) and ulcerative colitis (UC) are two chronic recurrent inflammatory processes of the gastrointestinal tract, grouped under the name Inflammatory Bowel Disease (IBD), causing clinical episodes of intestinal inflammation. The aim of this study was to investigate the possible association between IBD and the prevalence of apical periodontitis and root canal treatment.

METHODOLOGY

A case-control study design matched to age and sex was used. The study group (SG) included 28 patients with IBD (13 with CD, 15 with UC). Another 28 healthy subjects, without IBD and age- and sex- matched, were included in the control group (CG). Radiographic records were analyzed and apical periodontitis (AP) was diagnosed as radiolucent periapical lesions (RPLs), using the periapical index score (PAI). Student's t test, χ² test and multivariate logistic regression were used in the statistical analysis.

RESULTS

In the CG, only 17 subjects (61%) had at least one tooth with AP, while in the SG group they were 23 patients (82%) (OR = 2.98; CI 95% = 0.87 - 10.87; p = 0.08). The number of subjects with one or more root filled teeth (RFT) in the CG was 14 (50%), while in the SG they were 22 (79%) (OR = 3.67; 95% CI = 1.14 - 11.79; p = 0.026). At least one RFT with AP was evident in 3 subjects (10.7%) in the control group, while in the study group 15 patients (53.6%) showed RFT with AP (OR = 9.60; 95% CI = 2.35 - 39.35; p = 0.001). In the multivariate logistic regression analysis, only endodontic status was found to be associated with IBD (OR = 1.86; 95% CI = 1.24 - 2.80; p = 0.003).

CONCLUSION

IBD, ulcerative colitis and Crohn´s disease, is associated with higher prevalence of RFT and higher percentage of RFT with periapical lesions. Dentists should consider these findings when caring for IBD patients by monitoring the evolution of periapical lesions of endodontically treated teeth.

Type 2 diabetes and the clinically normal pulp - An in-vitro study

Aim

The aim of this study was to investigate the effect of type 2 diabetes (T2D) on clinically normal dental pulp tissue by using special stains and immunohistochemistry (IHC) to determine the morphology of the coronal pulp and distribution of immune markers in non‐T2D and T2D groups.

Methodology

Ethics approval for this in vitro pilot study was obtained from the University of Otago Human Ethics Committee (16/069). Twenty extracted permanent molar teeth diagnosed as having clinically normal pulp status were collected. Ten teeth were from participants with well‐controlled T2D and ten from participants without diabetes (non‐T2D). Each tooth was sectioned transversely at the cemento‐enamel junction before the crowns were decalcified and embedded in paraffin. Sections were stained with haematoxylin and eosin, Massons trichrome, and van Gieson stains for histological and morphological evaluation. IHC using anti‐CD4, anti‐CD68 and anti‐CD83 and anti‐IL1β, anti‐IL6, anti‐IL17, anti‐TNF‐α, anti‐TLR2, anti‐TLR4 and anti‐FOXP3 identified proteins of interest. Qualitative and semi‐quantitative analyses evaluated the morphology of the dental pulp and protein expression. Data analyses were performed with GraphPad Prism, using Student's t‐test and multiple regression using SPSS at p < .05.

Results

Special stains demonstrated morphological differences in the T2D dental pulp compared with non‐T2D. Qualitative analysis indicated that the pulp in the T2D samples was consistently less cellular, less vascular, showed evidence of thickened blood vessel walls, increased pulp calcification and collagen deposition. Semi‐quantitative analysis of IHC samples showed the T2D pulp had significantly increased expression of macrophage and dendritic cell markers CD68 (p < .001) and CD83 (p = .04), and there was significantly greater expression of inflammatory cytokines IL1β (p = .01), IL6 (p < .0001), IL17 (p < .0001) and TNF‐α (p = .01). T2D samples showed a significant increase in markers of innate inflammation, TLR2 (p < .001) and TLR4 (p < .001) and decreased expression of regulatory T‐cell marker, FOXP3 (p = .01). Multiple regression showed that age‐corrected differences were statistically significant.

Conclusion

Preliminary findings suggest that T2D may exert a similar response in the pulp to complications in other body sites. Hyperglycaemia is associated with changes in the morphology of the clinically normal dental pulp with altered immune cell and cytokine expression.

Leptin in Dental Pulp and Periapical Tissues: A Narrative Review

Leptin is a non-glycosylated 16 kDa protein synthesized mainly in adipose cells. The main function of leptin is to regulate energy homeostasis and weight control in a central manner. There is increasing evidence that leptin also has systemic effects, acting as a link between innate and acquired immune responses. The expression of leptin and its receptor in human dental pulp and periradicular tissues have already been described, as well as several stimulatory effects of leptin protein expression in dental and periodontal tissues. The aim of this paper was to review and to compile the reported scientific literature on the role and effects of leptin in the dental pulp and periapical tissues. Twelve articles accomplished the inclusion criteria, and a comprehensive narrative review was carried out. Review of the available scientific literature concluded that leptin has the following effects on pulpal and periapical physiology: 1) Stimulates odontogenic differentiation of dental pulp stem cells (DPSCs), 2) Increases the expression of dentin sialophosphoprotein (DSPP) and dentin matrix protein-1 (DMP-1), odontoblastic proteins involved in odontoblastic differentiation and dentin mineralization, 3) Stimulates vascular endothelial growth factor (VEGF) expression in human dental pulp tissue and primary cultured cells of human dental pulp (hDPCs), 4) Stimulates angiogenesis in rat dental pulp cells, and 5) Induces the expression of interleucinas 6 and 8 in human periodontal ligament cells (hPDLCs). There is evidence which suggests that leptin is implicated in the dentin mineralization process and in pulpal and periapical inflammatory and reparative responses.

A novel method for causal structure discovery from EHR data and its application to type-2 diabetes mellitus

Modern AI-based clinical decision support models owe their success in part to the very large number of predictors they use. Safe and robust decision support, especially for intervention planning, requires causal, not associative, relationships. Traditional methods of causal discovery, clinical trials and extracting biochemical pathways, are resource intensive and may not scale up to the number and complexity of relationships sufficient for precision treatment planning. Computational causal structure discovery (CSD) from electronic health records (EHR) data can represent a solution, however, current CSD methods fall short on EHR data. This paper presents a CSD method tailored to the EHR data. The application of the proposed methodology was demonstrated on type-2 diabetes mellitus. A large EHR dataset from Mayo Clinic was used as development cohort, and another large dataset from an independent health system, M Health Fairview, as external validation cohort. The proposed method achieved very high recall (.95) and substantially higher precision than the general-purpose methods (.84 versus .29, and .55). The causal relationships extracted from the development and external validation cohorts had a high (81%) overlap. Due to the adaptations to EHR data, the proposed method is more suitable for use in clinical decision support than the general-purpose methods.

Synergistic effects of silver ions and metformin against enterococcus faecalis under high-glucose conditions in vitro

Background

This study aimed to evaluate the synergistic antibacterial activities of silver ions (Ag⁺) and metformin hydrochloride (Met) against Enterococcus faecalis (E. faecalis) under normal or high-glucose conditions.

Results

The minimum inhibitory concentration, minimum bactericidal concentration, growth curves, and colony-forming units were used to evaluate the antibacterial effects of Ag⁺ and Met on planktonic E. faecalis in Brain Heart Infusion broth with or without additional glucose. The influences of Ag⁺ and Met on four weeks E. faecalis biofilm on human dentin slices was also tested. Cytotoxicity was tested on MC3T3-E1 osteoblastic cells using CCK-8 assays. The results indicated that E. faecalis showed higher resistance to drug treatment under high-glucose conditions. Ag⁺ (40 μg/mL) plus Met (3.2% or 6.4%) showed enhanced antibacterial activities against both planktonic E. faecalis and biofilm on dentin slices, with low cytotoxicity.

Conclusions

Met enhanced the bactericidal effects of Ag⁺ against both planktonic and biofilm E. faecalis under normal or high-glucose conditions with low cytotoxicity. Further molecular studies are needed to be conducted to understand the mechanisms underlying the synergistic activity between Met and Ag⁺.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02291-2.

Impact of endodontic and periodontal diseases and treatments on the aorta and liver of obese and non-obese rats

AIM

To evaluate the impact of the presence and treatment of periodontal disease (PD) and apical periodontitis (AP) on the aorta and liver of obese and non-obese rats.

METHODOLOGY

One hundred and forty Wistar rats were divided into two groups, according to the diet administered: normal diet (-n), without obesity; and cafeteria diet (-c), with induced obesity. These groups were divided into seven subgroups according to the specific experimental protocols: naïve control (NC); AP; AP with treatment (APt); PD; PE with treatment (PDt); AP and PD (APPD); and AP and PD with treatment (APPDt). AP and PD lesions were induced for four weeks. Four weeks after treatments, the animals were euthanatized, and the aorta and liver were dissected for histological evaluation. For the comparison of the thickness of the aorta between groups, the Kruskal-Wallis test was used, followed by the Mann-Whitney test. For the analysis of other variables related to the aorta and liver outcomes, logistic regression was carried out.

RESULTS

Both PD and AP were associated with the development of histological alterations in the aortic arch, with no significant difference between obese and non-obese animals (p = .17). The aorta thickness was increased significantly (p < .05) with the combination of PD and AP in obese rats (APPDt-c group) compared with the other groups (NC-n, APt-n, APt-c and AP-c). The logistic regression models revealed that the untreated (OR = 7.78; 95%CI = 2.4-25) and treated (OR = 2.9; 95%CI = 1.0-8.4) groups were significantly more likely to have endothelial alterations compared with the control groups (p = .002). Obesity (OR = 16.5; 95%CI = 3.4-81.3) was the only predictor variable of liver steatosis (p < .001).

CONCLUSION

Histological alterations in the aortic arch of obese and non-obese rats were observed in the presence of periodontal disease and apical periodontitis. The combination of PD and AP increased the aorta thickness in obese rats. A reduction of vascular endothelial lesions was observed with the treatments of PD and AP.

Evolution of endodontic medicine: a critical narrative review of the interrelationship between endodontics and systemic pathological conditions

Endodontics has gained emphasis in the scientific community in recent years due to the increase in clinical and in animal models studies focused on endodontic medicine, which aims to evaluate the interrelationship between systemic and periapical tissues pathological conditions. These studies have shown that systemic changes can boost the pathogenesis of endodontic infection, favoring its development and progression. A contrary relationship is reported in numerous studies that affirm the potential of endodontic infection to trigger systemic damage and may lead to the worsening of pre-existing pathologies. Recently, the potential of filling materials to develop systemic changes such as neurological alterations had been evaluated, also showing that systemic diseases can negatively influence tissue responses to filling materials after endodontic treatment. Despite advances in endodontic medicine studies, there are still gaps in knowledge on the mechanisms of interactions between apical periodontitis (AP) and systemic diseases and much research to be done. In this sense, this critical narrative literature review aimed to show the evolution of studies in endodontic medicine to help the endodontist to know the role of systemic diseases in the pathogenesis of AP and the possible interference in the repair of periapical tissues after endodontic treatment, as well as to evidence the systemic complications that can be triggered or aggravated in the presence of endodontic infection.

Impairment of the angiogenic process may contribute to lower success rate of root canal treatments in diabetes mellitus

AIM

To investigate the association between root canal treatment outcome, diabetes mellitus, and alterations of the angiogenic process.

METHODOLOGY

A retrospective observational study was conducted in healthy (control group, CG) and diabetic (type II diabetes mellitus group, DG) patients after root canal treatment. The follow-up appointments were performed to clinically and radiographically observe symptoms, the healing of periapical lesions and the quality of root fillings. In the animal model study, diabetic Goto-Kakizaki (GK) rats and control Wistar rats were used. After 21 days of pulp exposure and the development of apical periodontitis (AP), the mandibles were removed for scintigraphic, radiographic, histopathological and molecular analyses. Chi-square tests were performed to examine the variables related to endodontic outcome and differences between animal groups were assessed using the Student's t-test.

RESULTS

The group of patients with diabetes had a significantly lower rate of success following root canal treatment than the CG (p < .001). Logistic regression suggested that diabetes is a risk factor for success of root canal treatment. In the animal study, GK rats had significantly higher fasting glycaemia at t0 and t21 (p < .001) and triglycerides levels (p < .05) and area under the curve (AUC) during the insulin tolerance test at t21 (p < .001). AP area was significantly greater in GK rats (p < .05). Histologically, diabetic rats had increased signs of periodontal ligament inflammation 21 days after the induction of apical periodontitis, with fibro-hyaline matrix filling and vessel with undefined walls. Wistar rats had significantly increased vascular endothelial growth factor (VEGF) levels and VEGF/Ang-2 ratio 21 days after AP induction (p < .08; p < .07). GK rats had intrinsically lower levels of VEGF than control rats (p < .05), which did not change after AP.

CONCLUSION

Diabetes mellitus should be considered as an important factor in the prognosis of root canal treatment and its outcomes over time. Future strategies to improve angiogenesis and tissue repair should be pursued to achieve better root canal treatment outcomes in diabetic patients.

Prevalence of endodontic infection in patients with Crohn´s disease and ulcerative colitis

BACKGROUND

Previous studies have linked apical periodontitis (AP) to inflammatory bowel disease (IBD). The aim of this study was to compare the prevalence of AP and root canal treatment (RCT) in patients with ulcerative colitis (UC) and Crohn´s disease (CD).

MATERIAL AND METHODS

A cross-sectional study, including 28 patients with Crohn´s disease and 26 with ulcerative colitis, was conducted. AP was diagnosed as radiolucent periapical lesions (RPLs), using the periapical index score (PAI). Student's t test, 2 test and multivariate logistic regression were used in the statistical analysis.

RESULTS

Multivariate logistic regression run with age, gender, number of teeth, number of RFT, periodontal disease and the type of IBD as covariates, taking as dependent variable and outcome "periapical status" (0 = no tooth with RPL; 1 = at least one tooth with RPL), showed that both UC and CD patients had the prevalence apical periodontitis (OR = 1.03; C.I. 95% = 0.25 - 4.31; p = 0.97). The multivariate analysis, including all the above covariates, shows that both in UC and CD patients the prevalence of RCT was similar (OR = 0.76; C.I. 95% = 0.17 - 7.31; p = 0.73). Periapical status was significantly associated with endodontic status (OR = 42.72; C.I. 95% = 3.87 - 472.15; p = 0.002), regardless of IBD type.

CONCLUSIONS

The results of the present study show similar frequency of AP and RFT in both UC and CD patients. The type of IBD does not appear to affect the prevalence of radiographically detectable periapical lesions or the prevalence of root canal treatment.

Omega-3 Fatty Acids Alter Systemic Inflammatory Mediators Caused by Apical Periodontitis

INTRODUCTION

This study investigated the effects of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) on serum inflammatory mediators of rats with pulp exposure-induced apical periodontitis.

METHODS

Forty male Wistar rats were divided into the following groups: control, untreated rats (C); control rats treated with ω-3 PUFAs (C-O); rats with pulp exposure-induced apical periodontitis (AP); and rats with pulp exposure-induced apical periodontitis treated with ω-3 PUFAs (AP-O). ω-3 PUFAs were administered orally once a day for 15 days before pulp exposure and continued for 30 days after pulp exposure. The rats were sacrificed, and then blood and jaw samples were collected. Blood analysis was conducted to determine the total number of leukocytes including neutrophils, monocytes, and lymphocytes. Proinflammatory cytokines tumor necrosis factor alpha, interleukin (IL) 6, and IL-17 were quantified by enzyme-linked immunosorbent assay. Histologic analysis was performed to confirm the development of apical periodontitis. The data were statistically evaluated using analysis of variance and the Tukey posttest. The significance level was set at 5%.

RESULTS

The development of apical periodontitis was confirmed in all infected groups. Bone destruction was larger in the AP group compared with the AP-O group (P < .05). Blood analysis showed that the AP and AP-O groups showed higher numbers of lymphocytes, leukocytes, monocytes, eosinophils, and expressions of tumor necrosis factor alpha and IL-6 compared with the C and C-O groups (P < .05). In contrast, the presence of leukocytes, lymphocytes, and the expression of IL-6 decreased in the AP-O group compared with the AP group (P < .05).

CONCLUSIONS

ω-3 PUFA supplementation influences the systemic effects caused by apical periodontitis, decreasing the number of leukocytes, lymphocytes, and IL-6 in rat blood.

Relationship between Apical Periodontitis and Metabolic Syndrome and Cardiovascular Events: A Cross-Sectional Study

Aim: Both apical periodontitis (AP) and metabolic syndrome (MetS) are associated with atherosclerotic cardiovascular disease (ACVD), the main cause of cardiovascular events. The aim of this study was to investigate the prevalence of AP and the oral inflammatory burden in control subjects and patients suffering cardiovascular events, analyzing the possible association between AP and the oral inflammatory burden with MetS. Materials and Methods: Using a cross-sectional design, 83 patients suffering a cardiovascular event were recruited in the study group (SG), and 48 patients without cardiovascular events were included in the control group (CG). Periapical index (PAI) was used to diagnose AP, and total dental index (TDI) was used to assess the total oral inflammatory burden. Diagnosis of MetS was made by meeting three or more American Heart Association Scientific Statement components. Results: In the multivariate logistic regression analysis, the number of teeth with AP (OR = 2.3; 95% C.I. = 1.3–4.3; p = 0.006) and TDI scores (OR = 1.5; 95% C.I. = 1.2–1.9; p = 0.001), significantly correlated with cardiovascular events. MetS was strongly associated (OR = 18.0; 95% C.I. = 6.5–49.7; p = 0000) with cardiovascular events. Higher TDI scores were significantly associated with MetS (OR = 1.3; 95% C.I. = 1.1–1.6; p = 0.003. Neither the number of root-filled teeth (RFT) (OR = 0.9; 95% C.I. = 0.6–1.3; p = 0.61) nor the number of teeth with apical periodontitis (OR = 1.1; 95% C.I. = 0.8–1.7; p = 0.49) were associated with MetS. Conclusions: Apical periodontitis is significantly associated with cardiovascular events. Total oral inflammatory burden assessed by TDI, but not AP alone, is associated with MetS.

Cigarette Smoking and Root Filled Teeth Extraction: Systematic Review and Meta-Analysis

Aim: The aim of this systematic review and meta-analysis was to investigate the possible association between smoking habits and the occurrence of root-filled teeth (RFT) extraction. Material and Methods: The Population, Intervention, Comparison, and Outcome (PICO) question was in adult patients who had RFT, does the absence or presence of smoking habits affect the prevalence of extracted RFT? Systematic MEDLINE/PubMed, Wiley Online Database, Web of Science, and PRISMA protocol was used to evaluate and present the results. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system was used for certainty in the evidence. The risk of bias was assessed according to Cochrane Collaboration common scheme for bias and ROBINS-I tool. Cumulative meta-analysis was performed with a random effects model. PROSPERO registration code: CRD42020165279. Results: After search strategy, 571 articles were recovered, seven were selected for full-text analysis, and two reported data on inclusion criteria, including 516 RFT, 351 in non-smokers, and 165 in smoker subjects. The meta-analysis provided an odds ratio indicating significant association between smoking and the prevalence of extracted RFT (OR = 3.43, 95% CI = 1.17–10.05, p = 0.02, I² = 64%). The certainty of the literature assessment was low per GRADE. Both studies were considered as moderate risk of bias. Conclusions: Tobacco smoking should be considered a negative prognostic factor for the outcome of root canal treatment, although the quality of the evidence is low. RFT of smoking patients are three times more likely to be extracted. Continuing to smoke after endodontic treatment may increase the risk of treatment failure. However, the overall strength of evidence is low. This must be considered a limitation of the present study and the conclusion should be valued with caution.

Cardiovascular diseases and apical periodontitis: association not always implies causality

Background

Several studies published in the last two decades have found an association between the prevalence of apical periodontitis (AP) or root canal treatment (RCT) and cardiovascular diseases (CVDs). However, the demonstration of association does not prove by itself the existence of a cause–effect relationship. Two diseases can appear as statistically related without any of them directly affecting the values of the other, resulting in a non-causal relationship. The aim of this narrative review is to summarize the current state of knowledge regarding the association between AP and CVDs, analysing it according to the Hill's causality criteria.

Material and Methods

Epidemiological studies carried out on the association between CVDs and AP or RCT published in English until 8 December 2019 were identified. Forty-four articles were selected and its results were analysed.

Results

Numerous cross-sectional epidemiological studies have found significant relationship between CVDs and AP. The odds ratio values range 1.6 - 5.4. However, other studies have not found significant association. Respect to RCT, some studies found correlation, but others found no association or even found that RCT is a protective factor against CVDs.

Conclusions

The results are inconsistent and a causal relationship between CVDS and endodontic disease cannot be stablished. The risk factors common to both diseases can act as confounding factors, biasing the results. To reach definitive conclusions about the type of association (causal or non-causal) between both diseases, longitudinal epidemiological studies must be carried out to establish the temporal relationship and the dose-response gradient.

Key words:Apical periodontitis, atherosclerosis, cardiovascular disease, coronary heart disease, endodontic medicine, root canal treatment.

Relationship between apical periodontitis and atherosclerosis in rats: lipid profile and histological study

AIM

To investigate the relationship between apical periodontitis and atherosclerosis in rats by lipid profile and carotid artery intima tunic measurement, and histological and histometric evaluation of periapical lesions.

METHODOLOGY

Forty male Wistar rats were allocated into four groups: control (C), with apical periodontitis (AP), with atherosclerosis (AT) and with AP and AT (AP + AT). Atherosclerosis was induced using a high-lipid diet associated with a surgical ligature in the carotid artery and a super dosage of vitamin D₃ . AP was induced via pulp exposure to the oral environment. At 45 and 75 days, serum levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured. The maxillary and mandibular jaws and carotid artery were collected and processed for histological analysis. The Kruskal-Wallis or Mann-Whitney test was performed for nonparametric data, and the Tukey's or Student's t-test was performed for parametric data (P < 0.05).

RESULTS

In nonatherosclerotic animals, the induction of apical periodontitis increased TG levels significantly, from 63.1 ± 11.4 mg dL^-1 in group C to 88.2 ± 7.9 mg dL^-1 in the AP group (P < 0.05). The induction of AP was associated with a trend for higher TC and LDL-C levels in atherosclerotic animals (P > 0.05); however, it only significantly increased TG levels, from 93.2 ± 18.0 mg dL^-1 in AT group to 121.9 ± 14.5 mg dL^-1 in the AP + AT group (P < 0.05). Animals in the AP + AT group had a 36.5% increase in the thickness of the carotid intima tunic when compared with the AT group (P < 0.05). The intensity of the inflammatory infiltrate was significantly larger in the AP + AT group when compared with AP group (P < 0.05). The AP + AT group exhibited significantly greater alveolar bone loss, with a periapical lesion size of 206.4 ± 56.3 × 10⁴ μm² , compared with 151.4 ± 49.1 × 10⁴ μm² in the AP group (P < 0.05).

CONCLUSION

Apical periodontitis influenced triglyceride levels, increasing them even in the absence of atherosclerosis, and influenced the increase in the thickness of the carotid artery intima tunic in the presence of atherosclerosis. Atherosclerosis intensified the inflammatory reaction and increased bone resorption in periapical lesions.

Prevalence of Apical Periodontitis in patients with Multiple Myeloma

BACKGROUND

Aim Previous reports have been analyzed the prevalence/association of apical periodontitis (AP) with systemic diseases. The present study aims to analyze the prevalence of healthy/diseased periapex and endodontic treatments in patients with Multiple Myeloma (MM) and compare the results with those of control subjects.

MATERIAL AND METHODS

Methodology Panoramic radiographs of 50 individuals with MM were evaluated and compared with 50 controls that were sex and age matched exactly with the diseased group. Radiographic analysis was performed by 2 two experienced endodontists under standardized conditions. The periapical status (presence or not of AP) was assessed using the periapical index (PAI). Data included systemic health, technical quality of root fillings, total number of teeth, quality of restoration, and periapical status. Statistical evaluation of differences between groups included used chi-squared tests and Fisher's exact tests.

RESULTS

The prevalence of root canal-treated teeth was 10.11% in the MM group and 12.05% in the control group (p=0.90). The average root canal-treated teeth in the test group was 2,34 and 2.48 in the control group, where the difference was statistically significant (p=0.05). AP in 1 or more teeth was found in 86 % and in 78% of the patients in the MM and the control groups, respectively. When analyzed by subject, there was no statistically significant difference in the prevalence of AP (p>0.72). Similarly there was also no statistically significant difference in the prevalence of PA (p=0.85), when analyzed by tooth, AP was found in 63.2% and 62.9% in MM and control groups.

CONCLUSIONS

The presence of AP and endodontic treatment was not significantly different in individuals with MM compared with control subjects. Future studies are needed to elucidate and confirm the association between MM and AP.

Root Canal Treatment and Apical Periodontitis in a Brazilian Population with Type 1 Diabetes Mellitus: A Cross-sectional Paired Study

INTRODUCTION

This study radiographically analyzed the prevalence of root canal treatment (RCT) and apical periodontitis (AP) in type 1 diabetes mellitus (T1DM) and nondiabetic individuals and its association with the history/current status of T1DM.

METHODS

In a cross-sectional paired study, the radiographic records of 50 individuals with T1DM and 100 age- and sex-matched nondiabetic subjects were examined. The presence of RCT and AP was evaluated. Information regarding the history and current status of T1DM was collected from the medical records of each patient.

RESULTS

One or more RCTs were found in 76% and 44% of diabetic and nondiabetic subjects, respectively (P = .000). AP in 1 or more teeth was found in most T1DM patients (58%) and in 15% of the control subjects (P = .000). One or more RCTs associated with AP were found in 52% and 8% of T1DM and nondiabetic subjects, respectively (P = .000). Bivariate logistic regression analyses suggested that RCT (odds ratio [OR] = 10.435, P = .000), AP (OR = 3.508, P = .011), and RCT + AP (OR = 7.220, P = .000) were significantly associated with the presence of T1DM. Multivariate logistic regression showed that among T1DM individuals, there is an association between 11-15 years of diagnosis time and at least 1 RCT (OR = 46.316, P = .038) and an association between T1DM control and at least 1 tooth with AP (OR = 15.611, P = .016).

CONCLUSIONS

RCT, AP, and RCT with AP were more prevalent in individuals with T1DM than in nondiabetic individuals. RCT and AP were associated with the presence of T1DM, specifically RCT with diagnostic time and AP with glycemic control.

Apical Periodontitis and Diabetes Mellitus Type 2: A Systematic Review and Meta-Analysis

Objective: Investigate if there is an association between apical periodontitis and diabetes mellitus. Material and methods: A bibliographic search was performed on Medline/PubMed, Scopus and Cochrane databases using the keywords apical periodontitis and diabetes mellitus. Published papers written in English and performed on animals or humans were included. Meta-analysis was performed using the OpenMeta (analyst) tool for the statistical analysis. The variables analyzed were the prevalence of Apical Periodontitis (AP) among teeth and patients with Diabetes Mellitus (DM). Results: Of the total studies found, only 21 met the inclusion criteria. Ten clinical studies on animals, ten studies on humans and a systematic review were included. Meta-analysis shows that the prevalence of teeth with apical periodontitis among patients with diabetes mellitus has an odds ratio of 1.166 corresponding to 507 teeth with AP + DM and 534 teeth with AP without DM. The prevalence of patients with AP and DM shows an odds ratio of 1.552 where 91 patients had AP + DM and 582 patients AP without DM. Conclusion: Scientific evidence suggests that there could be a common physiopathological factor between apical periodontitis and diabetes mellitus but more prospective studies are needed to investigate the association between these two diseases.

High Prevalence of Apical Periodontitis in Patients With Inflammatory Bowel Disease: An Age- and Gender- matched Case-control Study

BACKGROUND

Deep carious lesions cause pulpitis, pulpal necrosis and, finally, apical periodontitis (AP). Root canal treatment (RCT) is the treatment of choice for AP, changing the tooth into a root-filled tooth (RFT). Several studies have linked AP and RFT to systemic diseases. Likewise, previous studies have also found an association among inflammatory bowel disease (IBD) and periodontal disease. This study aims to analyze the frequency of AP and RCT in IBD patients and healthy control subjects.

METHODS

An age- and gender-matched case-control study design was used. The study group (SG) included 54 IBD patients (28 with Crohn´s disease, 26 with ulcerative colitis). Another 54 healthy subjects without IBD and age- and gender-matched were included in the control group (CG). The radiographic records were analyzed, and periapical radiolucencies were diagnosed as AP, using the periapical index (PAI). The statistical analysis was carried out using the Student t test, χ 2 test, and multivariate logistic regression.

RESULTS

The presence of 1 or more teeth with radiolucent periapical lesions (RPLs) was found in 19 patients (35.2%) in the study group and in 9 subjects (16.7%) in the control group (P = 0.03). No differences were found among the 2 groups neither in the amount of teeth with AP nor in the number of RFTs (P > 0.05). However, multivariate logistic regression analysis adjusting for number of teeth and number of RFTs showed that patients with IBD have RPLs with higher likelihood than control patients (odds ratio, 5.7; confidence interval 95%, 1.7-19.1; P = 0.0048).

CONCLUSIONS

Subjects with inflammatory bowel disease have higher prevalence of apical periodontitis. An oral health protocol should be established to address the higher prevalence of inflammatory oral processes.