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Frontiers in Cellular and Infection... 2024and belong to the Bacteroidota phylum. Both species inhabit the oral cavity and can be associated with periodontal diseases. To survive, they must uptake heme from the...
INTRODUCTION
and belong to the Bacteroidota phylum. Both species inhabit the oral cavity and can be associated with periodontal diseases. To survive, they must uptake heme from the host as an iron and protoporphyrin IX source. Among the best-characterized heme acquisition systems identified in members of the Bacteroidota phylum is the Hmu system, with a leading role played by the hemophore-like HmuY (HmuY) protein.
METHODS
Theoretical analysis of selected HmuY proteins and spectrophotometric methods were employed to determine the heme-binding mode of the HmuY homolog (HmuY) and its ability to sequester heme. Growth phenotype and gene expression analysis of were employed to reveal the importance of the HmuY and Hmu system for this bacterium.
RESULTS
Unlike in , where HmuY uses two histidines for heme-iron coordination, other known HmuY homologs use two methionines in this process. HmuY is the first characterized representative of the HmuY family that binds heme using a histidine-methionine pair. It allows HmuY to sequester heme directly from serum albumin and HmuY, the HmuY homolog which uses two methionines for heme-iron coordination. In contrast to HmuY, which sequesters heme directly from methemoglobin, HmuY may bind heme only after the proteolytic digestion of hemoglobin.
CONCLUSIONS
We hypothesize that differences in components of the Hmu system and structure-based properties of HmuY proteins may evolved allowing different adaptations of species to the changing host environment. This may add to the superior virulence potential of over other members of the Bacteroidota phylum.
Topics: Heme; Porphyromonas gingivalis; Tannerella forsythia; Bacterial Proteins; Porphyromonas endodontalis; Humans; Gene Expression Regulation, Bacterial; Protein Binding; Iron
PubMed: 38938884
DOI: 10.3389/fcimb.2024.1421018 -
Frontiers in Cellular and Infection... 2024Recent studies have demonstrated a positive role of hyaluronic acid (HA) on periodontal clinical outcomes. This study aimed to investigate the impact of four different...
INTRODUCTION
Recent studies have demonstrated a positive role of hyaluronic acid (HA) on periodontal clinical outcomes. This study aimed to investigate the impact of four different HAs on interactions between periodontal biofilm and immune cells.
METHODS
The four HAs included: high-molecular-weight HA (HHA, non-cross-linked), low-molecular-weight HA (LHA), oligomers HA (OHA), and cross-linked high-molecular-weight HA (CHA). Serial experiments were conducted to verify the influence of HAs on: (i) 12-species periodontal biofilm (formation and pre-existing); (ii) expression of inflammatory cytokines and HA receptors in monocytic (MONO-MAC-6) cells and periodontal ligament fibroblasts (PDLF) with or without exposure to periodontal biofilms; (iii) generation of reactive oxygen species (ROS) in MONO-MAC-6 cells and PDLF with presence of biofilm and HA.
RESULTS
The results indicated that HHA and CHA reduced the bacterial counts in a newly formed (4-h) biofilm and in a pre-existing five-day-old biofilm. Without biofilm challenge, OHA triggered inflammatory reaction by increasing IL-1β and IL-10 levels in MONO-MAC cells and IL-8 in PDLF in a time-dependent manner, whereas CHA suppressed this response by inhibiting the expression of IL-10 in MONO-MAC cells and IL-8 in PDLF. Under biofilm challenge, HA decreased the expression of IL-1β (most decreasing HHA) and increased IL-10 levels in MONO-MAC-6 cells in a molecular weight dependent manner (most increasing CHA). The interaction between HA and both cells may occur via ICAM-1 receptor. Biofilm stimulus increased ROS levels in MONO-MAC-6 cells and PDLF, but only HHA slightly suppressed the high generation of ROS induced by biofilm stimulation in both cells.
CONCLUSION
Overall, these results indicate that OHA induces inflammation, while HHA and CHA exhibit anti-biofilm, primarily anti-inflammatory, and antioxidant properties in the periodontal environment.
Topics: Biofilms; Hyaluronic Acid; Humans; Reactive Oxygen Species; Fibroblasts; Cytokines; Monocytes; Periodontal Ligament; Cell Line; Interleukin-1beta; Interleukin-10
PubMed: 38938883
DOI: 10.3389/fcimb.2024.1414861 -
International Journal of Dentistry 2024This study aimed to evaluate the effect of autoclave sterilization on the integrity and instruments' fracture number after multiple uses and cyclic fatigue of the...
This study aimed to evaluate the effect of autoclave sterilization on the integrity and instruments' fracture number after multiple uses and cyclic fatigue of the original WaveOne Gold (Dentsply Sirona Endodontics) compared to four replica-like instruments (TF4-Gold, Roll-Wave-Gold, W-File, and Micro-Gold). The instruments were analyzed by scanning electron microscope (SEM) before being used in root canal instrumentation (baseline). One hundred and fifty human molars, freshly extracted for orthodontic reasons or periodontal disease and with severe curvature (between 30° and 60°), were used. Fifty teeth were instrumented with 10 instruments from each group and were evaluated for integrity. After sterilization in an autoclave, the instruments were analyzed by SEM. This procedure was repeated twice more, totaling three rounds of instrumentation, sterilization, and SEM analysis. Ten unused instruments from each group were evaluated for resistance to cyclic fatigue in a static test using a motor and a device simulating a canal with a 60° curvature angle. The instruments were driven by the motor until separation, visually verified, and the time measured in seconds. Data were analyzed by -square, one-way ANOVA, and Tukey analysis, considering a significance level of 5%. It was found that there was no statistically significant difference between the groups tested in the effect of sterilization on the number of uses. The SEM analysis showed distortions in the instruments after the 3rd use. There was a statistically significant difference in the cyclic fatigue test between the results of WaveOne Gold, TF4 Gold, and Roll Wave Gold compared to W File and Micro Gold ( < 0.0001) and a statistically significant difference between the W File and Micro Gold groups ( < 0.0001). In conclusion, this study affirmed that WaveOne Gold, TF4-Gold, and Roll-Wave-Gold instruments exhibit comparable cyclic fatigue resistance. Besides, all examined instruments can be reliably employed for up to two cases.
PubMed: 38938694
DOI: 10.1155/2024/6628146 -
Journal of Dentistry Jun 2024This study aimed to assess the association between posterior occlusal support (POS) and the risk of tooth loss in older adults aged ≥75 years.
OBJECTIVES
This study aimed to assess the association between posterior occlusal support (POS) and the risk of tooth loss in older adults aged ≥75 years.
METHODS
This longitudinal study analyzed 94,422 participants who participated in multiple dental check-ups provided as part of the public healthcare services in Osaka, Japan, from 2018 to 2022. The participants were categorized into nine groups (A1-3, B1-4, and C1 and C2) according to their POS status using the Eichner index at baseline. The dental charts were compared between the initial and final assessments to assess tooth loss. Logistic regression analysis was used to examine the association between POS status and tooth loss, adjusted for several covariates, including age, sex, body mass index, periodontal status, oral hygiene, history of diabetes, history of hypertension, attendance at the annual dental check-up, and observational period. Furthermore, stratified logistic regression analyses were conducted using anterior or posterior tooth loss.
RESULTS
After controlling for confounders, POS status was associated with tooth loss. The odds ratios (ORs) with A1 as the reference were 1.74 in A2, 2.55 in A3, 3.40 in B1, 4.74 in B2, 5.79 in B3, 6.00 in B4, 4.44 in C1, and 3.00 in C2, respectively. The ORs for anterior tooth loss were higher than those for posterior tooth loss, with the highest OR observed in B4 (21.4).
CONCLUSIONS
This large population-based cohort study showed that a decreased POS was a risk indicator for tooth loss; furthermore, the risk increased even further in the anterior teeth region.
PubMed: 38936455
DOI: 10.1016/j.jdent.2024.105144 -
STAR Protocols Jun 2024Periodontal ligament cells (PDLCs) and macrophages in bone marrow cells have been widely used to investigate novel therapeutic agents to treat periodontitis. Here, we...
Periodontal ligament cells (PDLCs) and macrophages in bone marrow cells have been widely used to investigate novel therapeutic agents to treat periodontitis. Here, we present a protocol for collecting primary mouse PDLCs and bone marrow cells. We detail steps for culturing and differentiation for both cell types and review data analysis for in vitro experiments using primary PDLCs and bone marrow cells. This protocol can be used to explore the impact of novel therapeutic agents using in vitro experiments. For complete details on the use and execution of this protocol, please refer to Sirisereephap et al..
PubMed: 38935507
DOI: 10.1016/j.xpro.2024.103162 -
Indian Journal of Dental Research :... Jan 2024The success of a combined periodontal and endodontic lesion depends on the elimination of both these disease processes. In the case of a combined endo-perio lesion,...
INTRODUCTION
The success of a combined periodontal and endodontic lesion depends on the elimination of both these disease processes. In the case of a combined endo-perio lesion, endodontic therapy results in healing of the endodontic component of involvement, while the prognosis of teeth would finally depend on the healing of the periodontal structure.
TREATMENT
This case report evaluates the efficacy of autologous fibrin glue and bone graft, that is, sticky bone in the management of bone defects associated with endo-perio lesion. The endo-perio lesion is first treated endodontically, followed by periodontal therapy. Conclusion: The patient was kept on follow-up for 9 months, and satisfactory results in terms of bone fill and reduction in pocket depth were obtained.
TAKEAWAY LESSONS
The sticky bone enhances regeneration in treatment of endo-perio lesions.
Topics: Humans; Bone Transplantation; Fibrin Tissue Adhesive; Root Canal Therapy; Male; Adult; Intercellular Signaling Peptides and Proteins
PubMed: 38934764
DOI: 10.4103/ijdr.ijdr_615_22 -
Indian Journal of Dental Research :... Jan 2024During orthodontic treatment, temporary anchoring devices (TADs) are used to restrain tooth movement. They are a relatively recent addition to the dental toolkit.
INTRODUCTION
During orthodontic treatment, temporary anchoring devices (TADs) are used to restrain tooth movement. They are a relatively recent addition to the dental toolkit.
AIM
As TADs have limitations, Dr. Eric Lieu of Taiwan developed Infra Zygomatic Crest (IZC) screws which are placed between the maxillary second premolar at the bony crest.
TREATMENT PLANNING
The goal of this case study is to emphasize the value of anatomy, site selection, and IZC retrieval in the event of an accident. Cone beam computed tomography was used as a diagnostic tool for the precise location of the displaced IZC and immediate surgical retrieval was done under local anesthesia from the infratemporal space to prevent further complications.
TAKEAWAY LESSONS
Orthodontists knowledge of soft tissue and hard tissue anatomy and precise positioning is crucial for successful TAD implantation.
Topics: Humans; Orthodontic Anchorage Procedures; Cone-Beam Computed Tomography; Zygoma; Bone Screws; Male; Female; Bicuspid; Maxilla; Tooth Movement Techniques
PubMed: 38934757
DOI: 10.4103/ijdr.ijdr_143_23 -
Indian Journal of Dental Research :... Jan 2024Wet oral environment may have deleterious effects on performance of the composites due to influences of water sorption and solubility. The study evaluated the hydrolytic...
INTRODUCTION
Wet oral environment may have deleterious effects on performance of the composites due to influences of water sorption and solubility. The study evaluated the hydrolytic degradation caused because of water sorption and solubility of silorane and methacrylate-based dental composites.
METHODS
Ten disc samples (2 mm × 10 mm) were prepared. Samples were analyzed for water solubility and sorption according to ISO 4049:2000 regulations and tested for mass gain or loss following immersion in water or in artificial saliva at 1 day, 15 days, and 30 days period. Student's 't' test, repeated measures analysis of variance (ANOVA), and Tukey's post-hoc tests determined statistical significance of the experimental results with global significance set at P = 0.05.
RESULTS
Considerable sorption and solubility was observed with time in both materials on immersion. Silorane composites showed lower water sorption and solubility than methacrylate-based composite (MBC). Artificial saliva demonstrated higher sorption and solubility compared to distilled water.
CONCLUSION
Silorane composites display enhanced hydrolytic stability even after a month of immersion in contrast to conventional methacrylate-based composites (MBCs), making it a better alternative to MBC resins clinically.
Topics: Solubility; Methacrylates; Composite Resins; Water; Silorane Resins; Saliva, Artificial; Materials Testing; Hydrolysis; Dental Materials
PubMed: 38934754
DOI: 10.4103/ijdr.ijdr_195_23 -
Indian Journal of Dental Research :... Jan 2024The application of direct current can have a significant impact on the rate of tooth movement and surrounding periodontal ligament collagen turnover. This study aims to... (Comparative Study)
Comparative Study
An Immunohistochemical and Histological Study of the Animal Periodontal Ligament During Orthodontic Force Application with Concomitant Application of Electric Current - An Animal Study.
INTRODUCTION
The application of direct current can have a significant impact on the rate of tooth movement and surrounding periodontal ligament collagen turnover. This study aims to provide insight into the optimal characteristics of applied current to achieve enhanced tissue response.
METHOD
Eighteen male Wistar rats were divided into three groups (I, II, and III). Split mouth design was used, and each side was allocated into an experimental group or control group. Experimental sides of groups I, II, and III received 20, 10, and 15 μA of current (15 min, twice daily for 3 days). Both the experimental and control groups receive an orthodontic force via the NiTi closed coil spring. The amount of tooth movement was determined daily. Immunohistochemistry slides were scored using the immunoreactive scoring (IRS) system for collagen types I and III. One-way Analysis of Variance (ANOVA) and Tukey post hoc test were used to analyse the rate of tooth movement, while Mann-Whitney test was used to analyse IRS distribution between control and experimental groups.
RESULTS
Compared with the control group, there was a statistically significant difference in tooth movement in all the experimental groups, with group 3 showing the maximum rate on days 2 and 3. This was supported by immunoreactive scores for both collagen types I and III.
CONCLUSIONS
After 72 hours, the expression of collagen types 1 and 3 increased significantly for group III. This finding was in harmony with the rate of tooth movement, which was maximum for group 3 (15 μA) as compared to other groups.
Topics: Periodontal Ligament; Animals; Rats, Wistar; Tooth Movement Techniques; Male; Rats; Collagen Type I; Immunohistochemistry; Collagen Type III; Orthodontic Wires; Dental Alloys; Nickel; Stress, Mechanical; Titanium
PubMed: 38934753
DOI: 10.4103/ijdr.ijdr_905_22 -
Indian Journal of Dental Research :... Jan 2024This study aimed to compare the efficacy of subgingivally applied probiotics as an adjunct to scaling and root planing (SRP) vs SRP alone in patients with periodontitis. (Randomized Controlled Trial)
Randomized Controlled Trial Comparative Study
AIM
This study aimed to compare the efficacy of subgingivally applied probiotics as an adjunct to scaling and root planing (SRP) vs SRP alone in patients with periodontitis.
MATERIALS AND METHODS
Patients diagnosed with periodontitis, with probing pocket depth (PPD) of 5-7 mm on at least two teeth on contralateral sites, were selected for the study and randomly allocated to the test group (n = 31) who underwent SRP along with subgingival application of probiotic paste and the control group (n = 31) who underwent only SRP. Clinical parameters were evaluated in both groups at baseline and after 12 weeks. The viability of probiotic bacteria was evaluated in the test group at baseline, day 4 and day 8.
RESULTS
All clinical parameters showed a statistically significant difference between baseline and 12 weeks on intragroup and intergroup comparison, with a greater improvement in the test group. Microbiological evaluation showed that the mean colony-forming units (CFUs) in the test group were 38.39 ± 7.76, 7.25 ± 2.72 and 1.57 ± 1.29 at baseline, day 4 and day 8, respectively. The mean CFUs significantly reduced with an increase in time from baseline to 8-day time interval.
CONCLUSION
It was seen that the probiotic bacteria remained viable in the periodontal pocket for up to 8 days after placement, but stable improvements were seen in all clinical parameters even at 12 weeks, indicating its prolonged efficacy. Thus, commercially available probiotics can prove to be an inexpensive method to treat periodontitis when combined with SRP.
Topics: Humans; Probiotics; Dental Scaling; Root Planing; Female; Male; Adult; Periodontitis; Middle Aged; Treatment Outcome; Periodontal Pocket; Periodontal Index; Combined Modality Therapy
PubMed: 38934751
DOI: 10.4103/ijdr.ijdr_533_23