Correlation between inflammatory infiltrate and epithelial lining in 214 cases of periapical cysts

The effect of changing apical foramen diameter on regenerative potential of mature teeth with necrotic pulp and apical periodontitis

OBJECTIVE

The aim of the present study was to evaluate the regenerative potential of permanent necrotic mature teeth with different apical foramen diameters in comparison to conventional endodontic treatment.

METHODS

Pulp necrosis and periapical pathosis were induced in premolars (144 roots) in six mongrel dogs. The infected teeth were divided into six groups; conventional root canal treatment (RCT) group prepared up to apical preparation sizes #F3 ProTaper file, regenerative endodontic therapy (RET) groups; groups RET-F3, RET-F4, and RET-F5 where regenerative endodontic procedures were applied after apical preparation up to sizes #F3, F4, and F5 ProTaper file, respectively, control groups; and positive (P) and negative (N) groups included infected and healthy teeth respectively. Each group (12 teeth with 24 roots each) was further subdivided into two subgroups (6 teeth with 12 roots each) according to the evaluation periods 1 and 3 months; each group was equally randomized in the upper and lower jaws during each evaluation period.

RESULTS

The inflammatory cell counts for the RCT group were statistically significantly higher than that of all RET groups at the first period and only significantly higher than RET-F5 at the second period. The enlargement of the apical foramen to #F5 showed no statistically significant difference with #F4 regarding the inflammatory cell count, tissue in-growth inside the root canal, and percentage of bone resorption. The tissue formed after RET was not true pulp tissue and is considered tissue repair with connective tissue, dilated blood vessels, and cementum-like structures.  CONCLUSION: Increasing the apical size diameter was associated with less inflammatory cell count, less percentage of bone resorption, more tissue ingrowth, and more percentage of new hard tissue formation inside root canal. The minimum apical diameter that should be enlarged for RET is 0.4 mm.

CLINICAL RELEVANCE

RET could be used as an alternative procedure to RCT for the treatment of mature teeth with necrotic pulp and apical periodontitis.

Ultrasound Imaging versus Radiographs in Differentiating Periapical Lesions: A Systematic Review

BACKGROUND

Ultrasonography is a non-invasive method of diagnosing periapical lesions while radiologic methods are more common. Periapical lesions due to endodontic infection are one of the most common causes of periapical radiolucency that need to be distinguished to help determine the course of treatment. This review aimed to examine the accuracy of ultrasound and compare it to radiographs in distinguishing these lesions in vivo.

METHODS

This review process followed the PRISMA guidelines. A literature search of databases (PubMed, Scopus, Embase, and Web of Science) was conducted without any restrictions on time. Articles available in English were included. The selection was done according to the inclusion and exclusion criteria. The QUADAS-2 tool was used to assess the quality of the studies.

RESULTS

The search provided a total of 87 articles, out of which, five were selected for the final review. In all the studies, ultrasound had higher accuracy in distinguishing periapical lesions. All the studies indicated a risk of bias, especially in patient selection.

CONCLUSION

Within limitations, the study indicates that ultrasound is a better diagnostic tool to distinguish periapical lesions compared to radiographs but further studies with well-designed, rigorous protocols and low risk of bias are needed to provide stronger evidence.

Chronic inflammatory periapical diseases: a Brazilian multicenter study of 10,381 cases and literature review

The aim of this study was to investigate the epidemiological and clinical characteristics of chronic inflammatory periapical diseases in different regions of Brazil and to compare with data from the literature. A multicenter study was carried out in four Brazilian referral centers in oral diagnosis. Histopathological records were reviewed, and all cases diagnosed microscopically as periapical granuloma, radicular cyst, and periapical abscess were included. Demographic and clinical data were collected. Descriptive statistics and Pearson's chi-square test were performed. A total of 10,381 cases of chronic inflammatory periapical diseases were found (13.8% of 74,931 archived specimens) over a period of 65 years. Radicular cysts were the most common lesion (59.9%). Women (56.1%) with a mean age of 37.01 years old (range 13 to 100 ± 14.42) and people of white skin color (59.2%) were the most affected individuals by chronic inflammatory periapical diseases. The lesions were generally asymptomatic (28.1%), located in the maxilla (60.1%), and posterior region (49.8%). The radicular cysts were larger when compared to periapical granulomas (p < 0.001). The disagreement between the clinical and histopathological diagnoses was higher when the final diagnosis was a periapical granuloma (p < 0.001). Chronic inflammatory periapical diseases continue to be common lesions affecting mainly adults. This should be a consequence of the burden of untreated caries in permanent teeth. Women are more affected and radicular cyst was the most common lesion.

Ultrasound imaging for the differential diagnosis of periapical lesions of endodontic origin in comparison with histopathology - a systematic review and meta-analysis

BACKGROUND

Differentiating periapical lesions is important for treatment planning and subsequent treatment outcome.

OBJECTIVE

To assess the diagnostic accuracy of ultrasound imaging for the differentiation of periapical lesions in comparison with histopathology.

METHODS

PubMed, Scopus, Embase, Web of Science and ProQuest databases were searched for clinical studies published until June 2020 that evaluated the use of ultrasound (US) imaging for differential diagnosis of periapical lesions and used histopathology as the reference standard. Animal studies, laboratory-based studies, reviews and clinical studies not using a reference standard were excluded. Risk of bias (RoB) assessment was performed using a modified Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. The random effects model was used for quantitative analysis of the data, and the Deeks test was used for calculating publication bias. Quality of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Twelve articles were included in the systematic review, out of which ten articles were quantitatively assessed. All the articles had a high RoB and concerns regarding applicability in the patient selection domain. For the index test domain, seven articles had low and the remaining five had unclear RoB and concerns regarding applicability. In the reference standard domain, low RoB and concerns regarding applicability were observed for all the articles. The RoB was low in flow and timing domains in all the articles except for one, where it was high. Summary estimates of sensitivity and specificity of US to diagnose periapical granulomas were 0.94 and 0.98, whereas for periapical cysts it was 0.98 and 0.99, respectively. Area under the curve for diagnosis of both periapical granulomas and periapical cysts was 0.99. All the included articles had inherent publication bias. Quality of evidence using GRADE, for sensitivity, was moderate for periapical granulomas and high for periapical cysts, whereas for specificity, it was high for periapical granulomas and low for periapical cysts.

DISCUSSION

The available evidence is considered to be of low quality due to the observational nature of the studies and inherent publication bias.

CONCLUSION

Although the sensitivity and specificity for differentiating periapical cysts and periapical granulomas using US were high, taking the quality of evidence into consideration, it can serve as an additional tool in differential diagnosis of periapical lesions.

Locally administered heparin-binding epidermal growth factor-like growth factor reduces radiation-induced oral mucositis in mice

Oral mucositis refers to lesions of the oral mucosa observed in patients with cancer being treated with radiation with or without chemotherapy, and can significantly affect quality of life. There is a large unmet medical need to prevent oral mucositis that can occur with radiation either alone or in combination with chemotherapy. We investigated the efficacy of locally administered heparin-binding epidermal growth factor-like growth factor (HB-EGF), a potent epithelial proliferation and migration stimulator of the oral mucosa as a potential therapy to prevent radiation induced oral mucositis. Using a single dose (20 Gy) of radiation to the oral cavity of female C57BL/6 J mice, we evaluated the efficacy of HB-EGF treatment (5 µl of 10 µg/ml) solution. The results show that HB-EGF delivered post radiation, significantly increased the area of epithelial thickness on the tongue (dorsal tongue (42,106 vs 53,493 µm2, p < 0.01), ventral tongue (30,793 vs 39,095 µm2, *p < 0.05)) compared to vehicle control, enhanced new epithelial cell division, and increased the quality and quantity of desmosomes in the oral mucosa measured in the tongue and buccal mucosa. This data provides the proof of concept that local administration of HB-EGF has the potential to be developed as a topical treatment to mitigate oral mucositis following radiation.

The presentation of odontogenic keratocysts in the jaws with an emphasis on the tooth-bearing area: a systematic review and meta-analysis

PURPOSE

This study was conducted in order to gain insight in the actual ratio of odontogenic keratocysts occurring in the tooth-bearing area as compared to the posterior region of the jaws in order to come up with reliable data to base upon a rational treatment policy.

METHODS

We searched MEDLINE, Web of Science, Scopus, and Cochrane databases for studies reporting on the location of mandibular and maxillary odontogenic keratocysts. All records were independently assessed and a meta-analysis was performed. Risk difference with a confidence interval of 95% of having the lesion in the posterior region versus the tooth-bearing area was the effect measure. P value for the summary effect of < 0.05 was considered statistically significant.

RESULTS

The 2615 records retrieved were reduced to 34 studies to be qualitatively/quantitatively assessed. The pooled values showed that the difference in the clinical risk of having keratocysts in the posterior region of the mandible and in the tooth-bearing area of the maxilla is 21 and 43%, respectively (P < 0.02 and P < 0.00001).

CONCLUSIONS

A substantial amount of keratocysts occur in the tooth-bearing area of the jaws, requiring attention.

Apical periodontitis: preliminary assessment of microbiota by 16S rRNA high throughput amplicon target sequencing

Background

Apical periodontitis includes periapical granulomas and radicular cysts, which are histologically distinguished by the absence and the presence of an epithelial lining, respectively. The main cause of apical periodontitis is the bacterial colonization of the root canal space. This research aimed at assessing whether and how periapical granulomas and radicular cysts differ in terms of microbiota using high throughput amplicon target sequencing (HTS) techniques.

Methods

This study included 5 cases of Periapical Granulomas (PGs) and 5 cases of Radicular Cysts (RCs) selected on the base of histology out of 37 patients from January 2015 to February 2016. Complete medical history, panoramic radiograms (OPTs) and histologic records of each patient were assessed. Only lesions greater than 1 cm in diameter and developed in proximity to teeth with bad prognosis were included. The microbiota present in periapical granulomas and radicular cysts thus retrieved was finely characterized by pyrosequencing of the 16S rRNA genes.

Results

The core of OTUs shared between periapical granulomas and radicular cysts was dominated by the presence of facultative anaerobes taxa such as: Lactococcus lactis, Propionibacterium acnes, Staphylococcus warneri, Acinetobacter johnsonii and Gemellales. L. lactis, the main OTUs of the entire datasets, was associated with periapical granuloma samples. Consistently with literature, the anaerobic taxa detected were most abundant in radicular cyst samples. Indeed, a higher abundance of presumptive predicted metabolic pathways related to Lipopolysaccharide biosynthesis was found in radicular cyst samples.

Conclusions

The present pilot study confirmed the different microbial characterization of the two main apical periodontitis types and shade light on the possible role of L. lactis in periapical granulomas.

Aging effects in the expression of macrophages in post-treatment apical periodontitis lesions

OBJECTIVES

To evaluate the CD68 immunoexpression in post-treatment apical periodontitis lesions of older patients and compare them with lesions of younger/middle age adults.

METHODS

Biopsy specimens from 21 apical periodontitis lesions (12 granulomas and 9 cysts) were selected from older patients and 25 apical periodontitis lesions from younger/middle age adults (12 cysts and 13 granulomas) were selected and analyzed by immunohistochemistry using silanized slides with anti-CD68 antibody. The slides were subdivided in five high-power fields and the images were observed under an optical microscope to evaluate the epithelial and connective tissues.

RESULTS

The results showed that there was no statistical difference for the CD68 expression in epithelial tissue of cysts between younger/middle age adults and older patients. However, for the connective tissue of both cysts and granulomas, there was a statistical difference between the two age groups. There was a statistical difference between the epithelial and the connective tissues in cysts of younger/middle age adults, and also when the epithelial tissue of the cysts was compared with connective tissue of the granuloma. In the group of older patients, there was no statistical difference between the connective tissue of the cysts and granulomas.

CONCLUSION

The intensity of the macrophage staining was greater in the connective tissue of cysts and granulomas alike in the younger/middle age adult patients, suggesting that these cells participate actively in this tissue. Immune responses in older patients may be compromised, suggesting that there is a greater tendency for the endodontic treatment of these patients to fail.

Immunohistochemical expression of TGF-β1 and MMP-9 in periapical lesions

The objective of this study was to evaluate the expression of matrix metalloproteinase 9 (MMP-9) and transforming growth factor beta (TGF-β1) in periapical lesion samples correlated with the intensity of the inflammatory infiltrate and thickness of the epithelial lining. Forty-five cases of periapical lesions (23 periapical granulomas and 22 radicular cysts) were subjected to morphological and immunohistochemical analyses using anti-MMP-9 and anti-TGF-β1 antibodies. The data were analyzed using the following tests: non-parametric Mann-Whitney, chi-square, Fisher's exact test and Spearman's correlation test (P<0.05). Analysis of inflammatory infiltrate revealed that 78% of periapical granulomas presented infiltrate grade III, in contrast with 32% of radicular cysts (P<0.001). Morphological evaluation of the epithelial thickness in radicular cysts revealed the presence of atrophic epithelium in 86% of the cysts. The immunostaining of MMP-9 was score 2 in 67% of the granulomas and 77% of the cysts. Both lesions were predominantly score 1 for TGF-β1. Significant differences were confirmed between the expression scores of TGF-β1 and MMP-9 in periapical granulomas (p = 0.004) and in radicular cysts (p < 0.001). Expression of TGF-β1 was different for periapical granulomas and radicular cysts. This immunoregulatory cytokine seems more representative in asymptomatic lesions. The extracellular matrix remodeling process dependent on MMP-9 seems to be similar for both periapical granulomas and radicular cysts. TGF-β1 and MMP-9 may play an important role in the maintenance of periapical lesions.

Bioinformatics, interaction network analysis, and neural networks to characterize gene expression of radicular cyst and periapical granuloma

INTRODUCTION

Bioinformatics has emerged as an important tool to analyze the large amount of data generated by research in different diseases. In this study, gene expression for radicular cysts (RCs) and periapical granulomas (PGs) was characterized based on a leader gene approach.

METHODS

A validated bioinformatics algorithm was applied to identify leader genes for RCs and PGs. Genes related to RCs and PGs were first identified in PubMed, GenBank, GeneAtlas, and GeneCards databases. The Web-available STRING software (The European Molecular Biology Laboratory [EMBL], Heidelberg, Baden-Württemberg, Germany) was used in order to build the interaction map among the identified genes by a significance score named weighted number of links. Based on the weighted number of links, genes were clustered using k-means. The genes in the highest cluster were considered leader genes. Multilayer perceptron neural network analysis was used as a complementary supplement for gene classification.

RESULTS

For RCs, the suggested leader genes were TP53 and EP300, whereas PGs were associated with IL2RG, CCL2, CCL4, CCL5, CCR1, CCR3, and CCR5 genes.

CONCLUSIONS

Our data revealed different gene expression for RCs and PGs, suggesting that not only the inflammatory nature but also other biological processes might differentiate RCs and PGs.

Correlation Between Histomorphometric and Micro-computed Tomography Analysis of Periapical Lesions in Mice Model

Periapical lesions are processes mediated from bacterial invasion on the pulp tissue, which results in inflammatory process and bone resorption. Animal models have been used for the study of cell interactions and inflammatory responses involved in periapical lesion. The use of different methods for morphometric evaluation of this lesion has been reported. However, due to the limitation of 2D methods, computerized microtomography (µCT) has been indicated. Therefore, the aim of this study was to evaluate the correlation between the histomorphometric measures of periapical lesions and the µCT analysis obtained in an animal experimental model. Briefly, the periapical lesions were induced by pulp exposal and after the experimental periods (7, 21 and 42 days) the mice were euthanized. The mandibles were evaluated under the µCT scanning and then were subjected to the routine histologic procedures, stained with hematoxilin and eosin. The periapical lesions were measured by the specific softwares of each technique. A weak correlation among the histomorphometric measurement and the 2D µCT analysis (r(2)= .204) and between the histomorphometric measurement and the 3D µCT analysis (r(2)= .237) was observed. A strong correlation between the 2D and 3D µCT analysis (r(2)= .867) was observed. Thereby, it can be concluded that the µCT is a method that allows a precise volumetric scanning and represents an important tool for morphometric evaluation.