Biological and chemical forms in controlling oral biofilms

Although there have been many advances in the medical field regarding disease control and management, it has been demonstrated that certain diseases and infections still represent a significant challenge. For example, the presence of oral biofilms indicates the virulence of the underlying infection in different dental infections diseases, including peri-implantitis, periapical periodontitis, periodontitis, gingivitis, and dental caries. We have discussed various mechanical, chemical, and biological modalities that can be applied to control biofilms and limit plaque formation and secondary caries. Although physical brushing might be efficacious in cleaning, evidence indicates that it cannot eradicate the underlying bacteria. Accordingly, using biological and chemical materials is essential to achieve adequate disinfection and enhance the outcomes. Many modalities have been proposed in the literature, such as nanomaterials, organic compounds such as arginine, dietary substances, and the various chemical oral cleansers discussed in the current study. Bacteriophages are also promising in this context. However, they need further exploration regarding their efficacy and safety. In addition, resistance against these compounds is a serious issue and needs to be addressed in future research.

Ckip-1 Mediates P. gingivalis–Suppressed Cementoblast Mineralization

Porphyromonas gingivalis is responsible for the destruction of cementum in patients with periodontitis and periapical periodontitis. However, research about the effects of P. gingivalis on cementoblast mineralization and the underlying mechanism is still lacking. Casein kinase 2 interacting protein 1 (Ckip-1) is a scaffold protein that interacts with various proteins and signals to regulate different cell functions, such as cell morphology, apoptosis, and differentiation. In this study, we verified the suppressive effects of P. gingivalis and lipopolysaccharide (Pg-LPS) on OCCM-30 mineralization. We also showed that Ckip-1 gradually decreased during OCCM-30 mineralization but increased with the aggravation of Pg-induced inflammation. However, it remained unchanged when cells were stimulated with Pg-LPS, regardless of the concentration and incubation time. Then, more cellular cementum and enhanced Osterix expression were observed in Ckip-1 knockout mice when compared with the wild-type mice. Meanwhile, Ckip-1 silencing significantly enhanced cementoblast mineralization with or without P. gingivalis–associated inflammation. The trend was opposite when Ckip-1 was overexpressed. Finally, we found that the p38, Akt, and Wnt pathways were activated, while the Erk1/2 pathway was inhibited when Ckip-1 was silenced. The opposite results were also observed in the Ckip-1 overexpression group. Furthermore, we proved that cell mineralization was weakened when p38, Akt inhibitors were applied and strengthened when the Erk1/2 pathway was inhibited. In summary, Ckip-1 is upregulated under P. gingivalis–induced inflammation and negatively regulates cementoblast mineralization partially through mitogen-activated protein kinases and Akt signaling pathways, which may contribute to the restoration of cementum destroyed by P. gingivalis.

Metabolome and microbiome of chronic periapical periodontitis in permanent anterior teeth: a pilot study

Background Periapical periodontitis is a common oral inflammatory disease that affects periapical tissues and is caused by bacteria in the root canal system. The relationship among the local metabolome, the inflammatory grade, and the type and abundance of microorganisms associated with periapical periodontitis is discussed in this study. Methods The inflammatory grades of periapical samples from 47 patients with chronic periapical periodontitis in permanent anterior teeth were determined based on the immune cell densities in tissues subjected to haematoxylin and eosin staining. The metabolome was evaluated using ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry, followed by principal component analysis and orthogonal partial least squares discriminant analysis. The microbiome was accessed using 16 S rRNA high-throughput sequencing. The differences in the metabolomes and microbiomes of the periapical periodontitis samples were assessed using Spearman’s correlation analysis. Result N-acetyl--glucosamine, -tryptophan, -phenylalanine, and 15 other metabolites were identified by the comparison between samples with severe inflammation and mild or moderate inflammation. Four amino acid metabolism pathways and one sugar metabolism pathway were associated with the inflammatory grade of periapical periodontitis. The abundance of Actinomycetes was negatively correlated with the abundance of glucosamine (GlcN), while the abundance of Tannerella was positively correlated with the abundance of -methionine. Conclusions The local metabolome of periapical periodontitis is correlated with the inflammatory grade. The abundance of the local metabolites GlcN and -methionine is correlated with the abundance of the major microorganisms Actinomycetes and Tannerella, respectively.

Morphological Changes of The Root Apex In Anterior Teeth With Periapical Periodontitis: An In-Vivo Study

Introduction: The aim was to analyze the morphological changes of root apex in anterior teeth with periapical periodontitis. Methods: 32 untreated anterior teeth with periapical periodontitis were enrolled, compared with the healthy contralateral teeth. Cone-beam computed tomography was used to measure diameter of the apical constriction. 3D reconstruction technique was used to reconstruct the teeth, analysis the constriction forms, and measure the distances of constriction to apical foramen and anatomical apex respectively. Results: The difference value between buccolingual and mesiodistal diameter was (0.06±0.09) mm in periapical periodontitis and (0.04±0.04) mm in healthy teeth (p<0.05). The mean distances between apical constriction and anatomical apex were (0.97±0.25) mm and (1.59±0.48) mm in periapical periodontitis and healthy teeth. The mean distances of apical constriction to apical foramen were (0.39±0.12) mm and (0.70±0.18) mm in periapical periodontitis and healthy teeth. The most common form of apical construction was flaring (65.6%) in periapical periodontitis. Conclusions: The anterior teeth with periapical periodontitis had shorter distances of apical constriction to anatomical apex and apical foramen, bigger disparities between the diameters of buccolingual and mesiodistal, and higher proportion of flaring apical construction.

The Wnt/β-catenin signaling pathway has a healing ability for periapical periodontitis

Various disease-related genes have recently been identified using single nucleotide polymorphisms (SNPs). This study identified disease-related genes by analyzing SNP using genomic DNA isolated from Japanese patients with periapical periodontitis. Results showed that the SNP in LRP5 demonstrated a significant genotypic association with periapical lesions (Fisher’s exact test, P < 0.05). We constructed an in vivo murine periapical periodontitis model to confirm the Wnt/β-catenin signaling pathway’s role in developing and healing periapical periodontitis. We observed that administration of the Wnt/β-catenin signaling pathway inhibitor enlarged the periapical lesion. Moreover, applying lithium chloride (LiCl) to root canals accelerated periapical periodontitis healing. Histological analysis demonstrated that the expression levels of Col1a1 and Runx2 increased in the LiCl application group compared to that in the control group. Furthermore, many CD45R-positive cells appeared in the periapical lesions in the LiCl application group. These results indicated that LiCl promoted the healing of periapical periodontitis by inducing bone formation and immune responses. Our findings suggest that the Wnt/β-catenin signaling pathway regulates the development of periapical periodontitis. We propose a bioactive next-generation root canal treatment agent for this dental lesion.

Prediction of thrust force and torque in canal preparation process using Taguchi method and Artificial Neural Network

Root canal preparation is a vital procedure during the treatment of pulposis and periapical periodontitis. However, the improper control of thrust force and torque in root canal preparation will cause nerve damage and cell necrosis. The aim of this study was to investigate and optimize the main factors influencing thrust force and torque and to establish an efficient predictive model for root canal preparation. This study was conducted on fresh bovine bones due to the similarity of structure and density with human teeth. A novel experimental platform was first built to measure the force and torque in canal preparation of different parameters. The effect of the experimental results on thrust force and torque was investigated based on Analysis of variance (ANOVA). The results indicated that the diameter of instrument, width of root canal, and feed rate are the most significant factors influencing the thrust forces and torque ( p < 0.05). Based on the above experiments, a Radial Basis Function Neural Network (RBFN) model was established to predict the thrust force and torque in a wider range of parameters. In confirmation tests, RBFN showed an excellent predictive model for prediction of thrust force and torque (error less than 14%) in canal preparation.

FISTULA MANAGEMENT DUE TO CHRONIC INFECTION OF RADICULAR CYST

A radicular cyst is the most common odontogenic cyst that arises from the epithelial residues in the periodontal ligament due to periapical periodontitis following death and necrosis of the pulp. A fistula may form a cyst with a pulp infection that produces pus and seeks its way out to the gingival surface to create a canal. The purpose of this case report is to report the management of a patient with a chronically infected radicular cyst with fistula while retaining the involved tooth. A case report was a 13-year-old female patient who came to Department Oral Surgery of a hospital with a complaint of a lump in the front gum and palate that didn't heal for two years ago and often discharged pus. Intraoral examination showed a lump in the gingiva and palate with fistula in the interdental gingiva of teeth 11-12 with soft consistency and pain with palpation. Panoramic results showed characteristics of the radicular cyst at the 13-11 tooth region. The lesion is diagnosed as a chronic infection of a radicular cyst due to pulp necrosis in teeth 12-11 with interdental fistulas. Biopsy enucleation of the cyst was performed with teeth preservation. The patient was advised to have regular check-ups. On the sixth month of control, the surgical wound was good, without any complaints and signs of recurrence. The result is that a radicular cyst can become chronically infected and form a fistula that oozes pus into the oral cavity. The cyst can be treated with enucleation biopsy and fistulectomy with the preservation, without any recurrences.

Use of the cone-beam computed tomography-endodontic radiolucency index for determination of lesion extension in periapical periodontitis

Background: Periapical periodontitis is caused by extension of necrotic pulp tissue into the periodontal ligament area. cone-beam computed tomography (CBCT) facilitates better diagnosis for periapical periodontitis, especially in the absence of clinical symptoms. This study aims to use cone-beam computed tomography-endodontic radiolucency index (CBCT-ERI) to determine the extension of periapical periodontitis in post-graduate clinics of Riyadh Elm university (REU) and to record the extension of periapical periodontitis in the coronal direction along the root surface and evaluate the degree of cortical bone involvement associated with periapical radiolucency.Methods: CBCT images for patients treated at the endodontic clinics of REU were selected for this retrospective observational study. Images were examined after inter-examiner calibrations under the same magnification, slice thickness, and resolution and the measurements were analyzed statistically.Results: The first permanent molars were the most frequently affected by periapical periodontitis, followed by the second molars. The majority of lesions were graded with a score of 6 in length and width according to CBCT-ERI.Conclusions: The use of CBCT-ERI revealed extensive involvement of periodontal tissues around the apices of the roots of the examined teeth. Coronal extension of periapical periodontitis was observed along the root surface. The axial view accurately detected cortical bone involvement, including thinning of the cortical bone, which was the most common manifestation (11.76%). Apical radiolucency was observed most commonly in the first molars.