Supporting Structures Of Teeth Research Articles

EFFECTS OF THE INSERTION OF AN ARCHWIRE THIN-WALLED SLEEVE IN ACCELERATING THE CANINE’S TRANSLATION

In sliding mechanics, resistance to sliding (RS), including friction, binding, and notching, generated at a wire-bracket interface has a bearing on the force transmitted to the teeth and further influences the biomechanical behavior associated with tooth movement efficiency. Objective: This study aimed to propose and verify the insertion of a rectangular thin-walled sleeve between an archwire and a bracket to minimize the resistance effect on the biomechanical behavior of tooth movement by using the finite element (FE) method. Material and methods: A 3D FE solid model was constructed and composed of mandibular dentitions, including the surrounding tooth-supporting structures and fixed self-ligating appliances. The translation of the left mandibular canine was simulated (0.1[Formula: see text]mm and 0.3[Formula: see text]mm) from the labial side to the lingual side with or without the thin-walled sleeve by using eight kinds of archwires with various dimensions and cross-sections by FE methods. Results: FE analysis indicated that the canine’s maximum initial displacement and the highest periodontal ligament (PDL) von Mises stress were mainly influenced by the orthodontic wire and the insertion of the thin-walled sleeve. Without the thin-walled sleeve, rectangular archwires could initiate a more optimal tissue response than round archwires. However, the insertion of the thin-walled sleeve between the small round archwire and the bracket significantly presented the most optimal biological responses in all of the cases. Conclusion: FE results revealed that the insertion of a thin-walled sleeve in a small round archwire and a bracket could have a positive influence on final tooth movement.

Critical Evaluation of the 2017 Classification of Periodontal and Peri-implant diseases and Conditions – An Update

Periodontal disease is the multifactorial disease that leads to the destruction of the tooth-supporting structures. A classification system provides a framework that helps in diagnosis and assembles similar disease phenotypes in a more homogeneous form. Several classifications have been proposed by many authors. Till date, the American Academy of Periodontology (AAP) 1999 Classification was the most extensively used classification, which was designed to overcome the drawbacks and deficiencies of the 1989 classification. However, presence of some drawbacks has limited its use in routine clinical practice. So, the current classification has been developed in 2017 by AAP and the European Federation of Periodontology (EFP) to overcome the disadvantages of the 1999 classification. The 2017 classification is extremely extensive and more intricate than 1999 classification, which is useful to the overall dentist and periodontists to select the best treatment options for the patients. This review summarizes the newer classification, key changes from 1999 Classification/modification and disadvantages of the newer classification.

Polymeric Carriers for Delivery Systems in the Treatment of Chronic Periodontal Disease.

Periodontitis (PD) is a chronic inflammatory disease of periodontal tissues caused by pathogenic microorganisms and characterized by disruption of the tooth-supporting structures. Conventional drug administration pathways in periodontal disease treatment have many drawbacks such as poor biodistribution, low selectivity of the therapeutic effect, burst release of the drug, and damage to healthy cells. To overcome this limitation, controlled drug delivery systems have been developed as a potential method to address oral infectious disease ailments. The use of drug delivery devices proves to be an excellent auxiliary method in improving the quality and effectiveness in periodontitis treatment, which includes inaccessible periodontal pockets. This review explores the current state of knowledge regarding the applications of various polymer-based delivery systems such as hydrogels, liposomes, micro-, and nanoparticles in the treatment of chronic periodontal disease. Furthermore, to present a more comprehensive understanding of the difficulties concerning the treatment of PD, a brief description of the mechanism and development of the disease is outlined.

The effect of laser irradiation and doxycycline application on the production of matrix metalloproteinase-8 and collagen I from cultured human periodontal ligament cells

Periodontal ligament fibroblasts (PDLF) play a key role in periodontal wound healing and tooth-supporting structures. Various approaches have been tried to enhance the fibroblastic activity such as laser irradiation or doxycycline application. The current study explored the influence of laser irradiation and doxycycline application on human PDLF. The aim of the study was the effect of low-level laser treatment and doxycycline application on the expression of collagen I and matrix metalloproteinase-8 (MMP8) from cultured human periodontal ligament cells. In this experimental study After preparation of human PDLF in three replications, they were divided into five treatment groups. The first group was day 0, which was used for standardization. The second group was the control group, which received no treatment within 4 days of the study. The third group was treated with doxycycline 30, daily for 4 consecutive days. The fourth group was treated with diode laser 2 daily for 4 consecutive days. The fifth group was treated with both doxycycline and laser irradiation pertaining to the third and fourth groups. After 4 days of treatment, cells were tested for collagen I and MMP-8 secretion through real-time-polymerase chain reaction and ELISA reader. The data were analyzed using the ANOVA and least significant difference pair tests ( P < 0.05 ). Treatment of human PDLF either with diode laser or doxycycline reduced the secretion of MMP-8 significantly. The maximum reduction was related to doxycycline application. Regarding collagen, I, only doxycycline application significantly increased collagen I secretion. Other groups showed no significant increase in collagen I secretion. This study showed that treatment of human PDLF either with diode laser or doxycycline significantly reduced MMP-8. Treatment with doxycycline significantly increased the secretion of collagen I.

Obesity and Periodontal Disease: A Narrative Review on Current Evidence and Putative Molecular Links

Background: Obesity represents one of the main health problems worldwide and is considered a risk factor for several diseases, including periodontitis, which is a microbially-associated inflammatory disease affecting the tooth-supporting structures. Objective: The aim of this review was to report the current direct and indirect evidence concerning the possible association between obesity and periodontitis and their putative molecular links. Methods: A literature search was conducted between January 1999 and September 2019, in PubMed/MEDLINE and Science Direct databases, using pertinent keyword combined by Boolean operators. Through a multi-step screening process (literature search; articles title and abstract evaluation and full-text reading), studies fitting inclusion/exclusion criteria were considered for the review. Results: 35 studies were included in the present review (17 observational studies; 7 systematic reviews; 11 systematic reviews with meta-analysis), focusing on the direct and indirect evidence of the possible association between obesity and periodontitis and their potential etiopathogenic molecular links Conclusion: Although the majority of the studies reported a positive association between obesity and periodontitis, the heterogeneity of the classification criteria and of the clinical parameters employed in the studies for both obesity and periodontitis evaluation, complicated the comparison of the results, thus considered inconclusive. Although several putative molecular pathogenic links between obesity and periodontitis have been highlighted, further studies, with longer follow-ups and with homogeneous clinical criteria, are needed to better understand the putative relation between obesity and periodontal disease.

Plasmin inhibition by bacterial serpin: Implications in gum disease

Tannerella forsythia is a periodontopathogen that expresses miropin, a protease inhibitor in the serpin superfamily. In this study, we show that miropin is also a specific and efficient inhibitor of plasmin; thus, it represents the first proteinaceous plasmin inhibitor of prokaryotic origin described to date. Miropin inhibits plasmin through the formation of a stable covalent complex triggered by cleavage of the Lys368-Thr369 (P2-P1) reactive site bond with a stoichiometry of inhibition of 3.8 and an association rate constant (kass) of 3.3×105M-1s-1. The inhibition of the fibrinolytic activity of plasmin was nearly as effective as that exerted by α2-antiplasmin. Miropin also acted in vivo by reducing blood loss in a mice tail bleeding assay. Importantly, intact T. forsythia cells or outer membrane vesicles, both of which carry surface-associated miropin, strongly inhibited plasmin. In intact bacterial cells, the antiplasmin activity of miropin protects envelope proteins from plasmin-mediated degradation. In summary, in the environment of periodontal pockets, which are bathed in gingival crevicular fluid consisting of 70% of blood plasma, an abundance of T. forsythia in the bacterial biofilm can cause local inhibition of fibrinolysis, which could have possible deleterious effects on the tooth-supporting structures of the periodontium.

Comparison of salivary level of leptin in chronic periodontitis patients and healthy controls

Objectives Periodontal disease is an inflammatory condition of the tooth-supporting structures. Leptin is a hormone produced by the human body under different circumstances such as infection. It affects the production of cytokines, phagocytosis and the inflammation process. This study aimed to compare the salivary level of leptin in chronic periodontitis (CP) patients and healthy controls.Methods In this case-control study, saliva samples were collected from 43 subjects including 22 CP patients and 21 healthy controls. The salivary level of leptin was determined using the ELISA. Data were analyzed by the independent t-test.Results Despite the presence of leptin in the saliva of CP patients and healthy controls, no significant difference was noted in its salivary concentration between the two groups (p>0.05).Conclusion The salivary level of leptin in CP patients was not significantly different from that in healthy controls. Further studies with larger sample size are required to confirm the results of this study

Berberine promotes osteogenic differentiation of mesenchymal stem cells with therapeutic potential in periodontal regeneration

Periodontal disease is a bacterial infection-associated disease of the periodontal tissues characterized by the destruction of tooth-supporting structures, including alveolar bone. The ideal goal of periodontal therapy is the complete regeneration of alveolar bone in a healthy microenvironment free of infection. In this study, we found that berberine, a benzylisoquinoline plant alkaloid from Coptidis Rhizoma, strongly inhibited the growth of Porphyromonas gingivalis. Gingipain is the most important virulence factor of Porphyromonas gingivalis in the process of periodontal tissue destruction. Berberine also had an inhibitory effect on gingipain activity in a concentration dependent manner. Remarkably, berberine restored the downregulation of osteogenesis-related genes expression in bone mesenchymal stem cells (BMSCs) induced by Porphyromonas gingivalis infection, and significantly increased the expression of osteogenesis-related genes such as OSX, COLI, ALP, OCN and OPN compared to the control group. This results suggested that berberine may directly promote osteogenesis. Further in-vitro studies demonstrated that berberine statistically significantly promoted the osteogenic differentiation of BMSCs at concentrations of 1–10 μM. In the research on the mechanisms, we found that both total β-catenin and nuclear β-catenin accumulation were statistically significantly increased by berberine. And the transcriptional activity of β-catenin/TCF was about 2 folds higher than the control group. Furthermore, Wnt signalling specific inhibitor DKK-1 blocked the above effects of berberine. These demonstrated that Wnt/β-catenin signalling pathway was involved in the osteogenic differentiation induced by berberine. The antibacterial actions in combination with the promotion role in osteogenic differentiation position berberine as a prospective drug for periodontal tissue regeneration.

Dysregulation of miR-146a by periodontal pathogens: A risk for acute coronary syndrome.

Periodontitis is a polymicrobial, chronic inflammatory disease leading to loss of tooth-supporting structures. The bacteremia, endotoxemia, and systemic low-grade inflammation associate periodontitis with systemic illnesses such as diabetes mellitus and coronary artery disease. Periodontal pathogens have been detected from atheromatous plaque by amplification of the genetic material by using specific oligonucleotide primers in polymerase chain reaction. Though the association between periodontitis and cardiovascular diseases has been ascertained by systematic reviews and meta-analyses, its pathophysiology is not lucid. MicroRNAs are currently implicated in the regulation of many cellular processes including inflammation and may play a vital role in our understanding of this disease association. In this case-control study, we explored the role of the inflammatory microRNA, miR-146a, in acute coronary syndrome (ACS) subjects with and without chronic periodontitis (CP) and its regulation of the innate immune host response to periodontal pathogens. Three groups each comprising 66 patients each, namely group 1 (ACS patients without CP), group 2 (ACS patients with CP) and group 3 (CP only) formed the study population. Subgingival plaque samples and serum samples were subjected to quantitative Polymerase Chain Reaction (qPCR) for detection of Porphyromonas gingivalis, a keystone pathogen and to assess the levels of circulating miR-146a and associated proinflammatory cytokines. miR-146a associated significantly in group 2 subjects with an odds ratio 1.434, 95% confidence interval 1.013-2.030, P<0.042, and a predictive percentage of 83.3% and group 1 with a predictive percentage of 76.0.% The associated cytokines interleukin-6 (IL-6), tumor necrosis factor-α, and IL-1β also showed an upregulation with statistical significance (P<0.05). microRNA-146a is a key molecule associating periodontitis with acute coronary syndrome.

Novel Bioactive and Therapeutic Dental Polymeric Materials to Inhibit Periodontal Pathogens and Biofilms.

Periodontitis is a common infectious disease characterized by loss of tooth-supporting structures, which eventually leads to tooth loss. The heavy burden of periodontal disease and its negative consequence on the patient’s quality of life indicate a strong need for developing effective therapies. According to the World Health Organization, 10–15% of the global population suffers from severe periodontitis. Advances in understanding the etiology, epidemiology and microbiology of periodontal pocket flora have called for antibacterial therapeutic strategies for periodontitis treatment. Currently, antimicrobial strategies combining with polymer science have attracted tremendous interest in the last decade. This review focuses on the state of the art of antibacterial polymer application against periodontal pathogens and biofilms. The first part focuses on the different polymeric materials serving as antibacterial agents, drug carriers and periodontal barrier membranes to inhibit periodontal pathogens. The second part reviews cutting-edge research on the synthesis and evaluation of a new generation of bioactive dental polymers for Class-V restorations with therapeutic effects. They possess antibacterial, acid-reduction, protein-repellent, and remineralization capabilities. In addition, the antibacterial photodynamic therapy with polymeric materials against periodontal pathogens and biofilms is also briefly described in the third part. These novel bioactive and therapeutic polymeric materials and treatment methods have great potential to inhibit periodontitis and protect tooth structures.

Immunization against Porphyromonas gingivalis for Prevention of Experimentally Induced Periodontitis in Rats

Aim: Periodontitis is an inflammatory disease causing destruction of tooth-supporting structures. It is often caused by gram-negative microorganisms such as Porphyromonas gingivalis (P. gingivalis). Common treatments for periodontitis are often nonspecific and include mechanical plaque removal and surgery. This study aimed to assess the amount of bone loss and antibody titer against P. gingivalis in rats. Materials and methods: This in vitro experimental study was conducted on 66 Surrey rats free of black pigmented pathogens, which were randomly divided into six groups of 11. Groups I and II were vaccinated with formalin-killed whole-cell (FKWC) P. gingivalis with incomplete Freund’s adjuvant as the vaccine carrier, and groups III and IV were vaccinated with incomplete Freund’s adjuvant and PG buffer. Groups V and VI were considered as positive and negative controls, respectively. Three weeks later, they were vaccinated with a booster dose. At 28 days, groups I, III, and V were inoculated with viable P. gingivalis (ATCC 33277) four times at 48-hour intervals for induction of periodontitis. One week after booster dose administration and two weeks after oral inoculation of bacteria, serum and saliva samples were obtained for assessment of antibody titer. Ten weeks after final bacterial inoculation, the serum and saliva samples were obtained to assess antibody titer, and subgingival plaque samples were obtained from the maxillary second molar site to assess the bacterial count. The rats were then sacrificed to assess bone loss. Results: Serum and saliva antibody titers in groups I and II were significantly different from those in other groups one week after booster dose and two and 10 weeks after oral inoculation of bacteria (p 0.99), but had a significant difference with the positive control (group V) and group III (p < 0.001). Conclusion: This study showed successful immunization against P. gingivalis, which increased serum IgG and saliva IgA titers, limited the colonization of P. gingivalis in subgingival plaque, and restricted the alveolar bone loss. © 2019, Jaypee Brothers Medical Publishers (P) Ltd. All rights reserved.

Periodontal splints: Past to present: A review

Tooth mobility is caused by the loss of tooth-supporting structures. Increased tooth mobility has a negative impact on function, appearance, and patient comfort. Splints are utilized to solve all of these issues. Splinting mobile teeth to stronger adjacent teeth is a possible solution when faced with the challenge of how to maintain periodontally damaged teeth. This extends the life of loose teeth and provides stability for the periodontium. Tooth stabilization and splinting have been used to reduce tooth mobility, replace lost teeth, and improve shape, function, and esthetics since ancient civilization. Conservative bonding treatments to splint teeth have become a popular option to more intrusive restorative operations in recent years. Splinting its, basic concepts, classifications indications, contraindications, limitations, and various splints from past to present are all discussed in this article.

The Association between Chronic Periodontitis and Chronic Obstructive Pulmonary Disease - A Review

Periodontitis is an inflammatory disease, which is characterized by the destruction of the tooth-supporting structures resulting from an overreaction of the inflammatory process. Chronic obstructive pulmonary disease (COPD) is a prime pulmonary disease characterized by a limitation in the airflow.

Primary immunodeficiencies reveal the essential role of tissue neutrophils in periodontitis.

Periodontitis is a common human inflammatory disease. In this condition, microbiota trigger excessive inflammation in oral mucosal tissues surrounding the dentition, resulting in destruction of tooth-supporting structures (connective tissue and bone). While susceptibility factors for common forms of periodontitis are not clearly understood, studies in patients with single genetic defects reveal a critical role for tissue neutrophils in disease susceptibility. Indeed, various genetic defects in the development, egress from the bone marrow, chemotaxis, and extravasation are clearly linked to aggressive/severe periodontitis at an early age. Here, we provide an overview of genetic defects in neutrophil biology that are linked to periodontitis. In particular, we focus on the mechanisms underlying Leukocyte Adhesion Deficiency-I, the prototypic Mendelian defect of impaired neutrophil extravasation and severe periodontitis.

SOD2 is upregulated in periodontitis to reduce further inflammation progression

Periodontitis is a highly prevalent chronic inflammatory disease that results in destruction of tooth-supporting structures followed by tooth-loss. Until now, periodontitis has been regarded to be initiated by bacterial infection followed by aberrant host response. Although increasing evidence suggests a strong association between oxidative stress and periodontitis, precise molecular mechanism has been left unanswered. In this study, we investigated roles of SOD2, the main antioxidant enzyme maintaining reactive oxygen species (ROS) homeostasis, under inflammatory conditions. We computationally analyzed SOD2 expression in periodontitis. To confirm this data, immunoblot assay was performed with samples from periodontitis patients. The cellular mechanism of change in SOD2 expression was identified through immunoblot assay and immunofluorescence. To evaluate the molecular function of SOD2, we generated SOD2-deficient cells by utilizing the CRISPR/Cas9 system. We first determined that SOD2 expression was significantly increased in periodontitis. We also confirmed that SOD2 expression was upregulated through the NF-κB pathway when the inflammatory signal was stronger and extended. Gene manipulation against SOD2 through the CRISPR/Cas9 system showed that the absence of SOD2 increased production of NLRP3 inflammasome components. Our study demonstrates that intracellular SOD2 has a protective role by suppressing NLRP inflammasome-caspase-1-IL-1β axis under inflammatory conditions.

Roles of Oral Infections in the Pathomechanism of Atherosclerosis.

Oral infections occur frequently in humans and often lead to chronic inflammations affecting the teeth (i.e., caries), the gingival tissues surrounding the teeth (i.e., gingivitis and endodontic lesions), and the tooth-supporting structures (i.e., periodontitis). At least four basic pathogenic mechanisms have been proposed that involve oral inflammations in the pathogenesis of atherosclerosis: (1) low level bacteremia by which oral bacteria enter the blood stream and invade the arterial wall; (2) systemic inflammation induced by inflammatory mediators released from the sites of the oral inflammation into the blood stream; (3) autoimmunity to host proteins caused by the host immune response to specific components of oral pathogens; (4) pro-atherogenic effects resulting from specific bacterial toxins that are produced by oral pathogenic bacteria. In this narrative review, we summarize published experimental evidence related to these four mechanisms and discuss their impact on the pathogenesis of atherosclerosis.

Genomewide Association Study Identifies Cxcl Family Members as Partial Mediators of LPS-Induced Periodontitis.

Periodontitis (PD) is characterized by bacterial infection and inflammation of tooth-supporting structures and can lead to tooth loss. PD affects ∼47% of the US population over age 30 years and has a heritability of about 50%. Although the host immunoinflammatory response and genetic background play a role, little is known of the underlying genetic factors. We examined natural genetic variation in lipopolysaccharide (LPS)-induced PD across a panel of inbred mouse strains, the hybrid mouse diversity panel (HMDP). We observed a strain-dependent sixfold difference in LPS-induced bone loss across the HMDP with a heritability of 53%. We performed a genomewide association study (GWAS) using FAST-LMM, which corrects for population structure, and identified loci significantly associated with PD. We examined candidate genes at a locus on chromosome 5, which suggested a relationship between LPS-induced bone loss and, together with expression data, identified Cxcl family members as associated with PD. We observed an increase in Cxcl10 protein, as well as immune cells and pro-inflammatory cytokines in C57BL/6J (high bone loss strain) but not in A/J (low bone loss strain) after LPS injections. Genetic deletion of CXCR3 (Cxcl9 and10 receptor) demonstrated a ∼50% reduction in bone loss and reduced osteoclasts after LPS injections. Furthermore, WT mice treated with AMG-487 (a CXCR3 antagonist) showed a ∼45% reduction in bone loss and decreased osteoclasts after LPS injections. We conclude that CXCR3 is a strong candidate for modulating the host response in individuals susceptible to PD. © 2018 American Society for Bone and Mineral Research.

Autotransplantation, Surgical Repositioning of Retained Canine, and Apical Filling of Two Incisors with Root Resorption.

The purpose is to show the autotransplantation and surgical repositioning of a retained canine, and the apical filling of central and lateral resorbed incisors from a 12-year-old female patient, healthy and with clinical absence of left maxillary canine. Radiographically, the retained canine between the resorbed central and lateral incisors was observed. Root canal treatment of the canine was performed after 8 weeks; apical curettage and placement of bovine graft in inter-incisal zone was done after 4 months. During 6 months, orthodontic traction of the canine was carried out with no positive results, and 12 months after the autotransplantation, surgical repositioning was performed. Clinical-radiographic control at 30 days and 24 months showed absence of inflammation, restoration and integration of the tooth-supporting structures. Autotransplantation combined with surgical repositioning of the retained canine and the apical filling of two incisors achieved the harmonious, aesthetic, functional, dental and psychological preservation of the patient.

Diagnosis of aggressive periodontitis: A dilemma?

Periodontitis is one of the leading causes of tooth loss in the adult population. This disease can be classified into various categories, and one of the most destructive amongst them is aggressive periodontitis (AgP). The incidence of AgP is lower than other types of periodontitis. However, it affects young individuals and can cause severe destruction of tooth-supporting structures including tooth loss if left untreated. The current classification for diagnosing periodontal disease was established by the American Academy of Periodontology (AAP) in 1999. This classification provided strict guidelines to aid in AgP diagnosis. These include three main factors: systemically healthy individual, rapid loss of clinical attachment, and familial aggregation. In spite of these specific guidelines, AgP diagnosis is often missed clinically due to various reasons. There is still a vast variation in the diagnostic criteria for identifying AgP and not all practitioners utilize the AAP guidelines for their diagnosis. Furthermore, the definition of the disease might be changing in the future to better represent the current understanding of the disease. Since early diagnosis and prompt treatment is key in treating these patients, it is important to have calibration in the diagnosis process. This review aims to identify sources of variation and ambiguity in diagnosing AgP among dental practitioners. For this purpose, we have conducted an extensive literature search and outlined the various diagnostic aids for AgP patients reported in the literature. Understanding and correcting these variations can simplify the diagnostic process leading to faster treatment of patients affected with AgP. This review also emphasizes the importance of minimizing the bias in identifying patients with AgP and highlights the best tools for this purpose.

Evaluation of Clinical Effects of a 940nm Diode Laser as Adjunctive Therapy in the Treatment of Periodontal Pockets

Background : Periodontal diseases are multifactorial, inflammatory diseases that, when left without treatment may results in the destruction of tooth-supporting structures and finally may cause tooth loss. Diode laser therapy as an adjunct to non-surgical peri- odontal treatment of periodontal pockets has been increasingly encouraged by some researches but experimental proves have not yet supported the use of laser therapy. Aim: The objective of this single controlled clinical study was to assess the effect of a 940-nm diode laser as an adjunct to scaling and root planing (SRP) therapy in the treatment of periodontal pockets. Methods : Fifteen patients in need of periodontal treatment with periodontal pocket ≥ 4 were selected for this split-mouth clinical study. Quadrants were enrolled into either control group treated by conventional scaling and root planning or test group treated by diode laser 940nm as an adjunct with SRP in contralateral quadrants. Baseline data, including plaque index (PI), gingival index (GI), probing pocket depth (PPD) were recorded before the treatment and 3 months post treatment. Results: plaque index (PI), gingival index (GI), probing depth (PD) were significantly reduced after 3 months in both groups. No significant differences were found in reduction mean of PI, GI, PPD. Conclusion : The use of the diode laser as an adjunct to scaling and root planing did not offer any superior clinical benefits over conventional scaling and root planning.