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About Zhang T, Ying D, Qi M, Li X, Fu L, Sun X, Wang L, Zhou Y.

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So far Zhang T, Ying D, Qi M, Li X, Fu L, Sun X, Wang L, Zhou Y. has created 994 blog entries.

Anti-Biofilm Property of Bioactive Upconversion Nanocomposites Containing Chlorin e6 against Periodontal Pathogens

Photodynamic therapy (PDT) based periodontal disease treatment has received extensive attention. However, the deep tissue location of periodontal plaque makes the conventional PDT encounter a bottleneck. Herein, upconversion fluorescent nanomaterial with near-infrared light excitation was introduced into the treatment of periodontal disease, overcoming the limited tissue penetration depth of visible light in PDT. Photosensitizer Ce6 molecules were combined with upconversion nanoparticles (UCNPs) NaYF4:Yb,Er with a novel strategy. The hydrophobic UCNPs were modified with amphiphilic silane, utilizing the hydrophobic chain of the silane to bind to the hydrophobic groups of the UCNPs through a hydrophobic-hydrophobic interaction, and the Ce6 molecules were loaded in this hydrophobic layer. This achieves both the conversion of the hydrophobic to the hydrophilic surface and the loading of the oily photosensitizer molecules. Because the excitation position of the Ce6 molecule is in the red region, Mn ions were doped to enhance red light, and thus the improved PDT function. This Ce6 loaded UCNPs composites with efficient red upconversion luminescence show remarkable bacteriological therapeutic effect on Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum and the corresponding biofilms under 980 nm irradiation, indicating a high application prospect in the treatment of periodontal diseases.

Marijuana-derived cannabinoids trigger a CB2/PI3K axis of suppression of the innate response to oral pathogens.

Cannabis use is an emergent risk factor for periodontitis, a chronic bacterial-induced disease of the supporting structures of the teeth. However, the mechanisms by which marijuana exposure predisposes to periodontal tissue destruction have yet to be elucidated. Therefore, we examined the influence of physiologically relevant doses of major marijuana-derived phytocannabinoid subtypes (cannabidiol [CBD]; cannabinol [CBN]; and tetrahydrocannabinol [THC], 1.0 μg/ml) on the interactions of three ultrastructurally variant oral pathogens, Porphyromonas gingivalis, Filifactor alocis, and Treponema denticola with the immune system. CBD, CBN, and THC each suppressed P. gingivalis-induced IL-12 p40, IL-6, IL-8, and TNF release while enhancing the anti-inflammatory cytokine, IL-10, from human innate cells. Similar phenomena were observed in F. alocis- and T. denticola-exposed human monocytes and human gingival keratinocytes. Higher phytocannabinoid doses (≥5.0 μg/ml) compromised innate cell viability and inhibited the growth of P. gingivalis and F. alocis, relative to unexposed bacteria. T. denticola, however, was resistant to all cannabinoid doses tested (up to 10.0 μg/ml). Pharmaceutical inhibition and efficient gene silencing indicated that a common CB2/PI3K axis of immune suppression is triggered by phytocannabinoids in vitro. This pathway does not appear to perpetuate through the canonical GSK3β-dependent cholinergic anti-inflammatory pathway, the predominant endogenous inflammatory control system. In a repetitive, transient oral infection model, CBD also suppressed P. gingivalis-induced innate immune markers in wild-type mice, but not in CB2-/- mice. If such phenomena occur in humans in situ, environmental cannabinoids may enhance periodontitis via direct toxic effects on specific oral bacteria; by compromising innate cell vitality; and/or through a suppressed innate response to periodontal pathogens involving a CB2/PI3K signaling lineage.

A Literature Review Study on Atomic Ions Dissolution of Titanium and Its Alloys in Implant Dentistry.

This review of literature paper was done in order to conduct a review of the literature and an assessment of the effects of titanium implant corrosion on peri-implant health and success in the oral environment. This paper evaluates and critically reviews the findings of the multiple in-depth in vivo and in vitro studies that are related to corrosion aspects of the titanium and its alloys. A literature survey was conducted by electronic search in Medline and studies that were published between 1940 and August 2018 were selected. The search terms used were types of corrosion, corrosion of titanium implants, titanium corrosion, metal ion release from the titanium implants, fretting and pitting corrosion, implant corrosion, peri implantitis, and corrosion. Both in vivo and in vitro studies were also included in the review. The search and selection resulted in 64 articles. These articles were divided on the basis of their context to different kinds of corrosion related to titanium dental implants. It is evident that metal ions are released from titanium and titanium alloy dental implants as a result of corrosion. Corrosion of implants is multifactorial, including electrical, chemical, and mechanical factors, which have an effect on the peri-implant tissues and microbiota. The literature surveyed showed that corrosion related to titanium and its alloys has an effect on the health of peri-implant soft and hard tissue and the long term survival of metal dental implants. It can be concluded that presence of the long-term corrosion reaction along with continuous corrosion leads to the release of ions into the peri-implant tissue but also to a disintegration of the implant that contribute to material fatigue and even fracture of the abutments and implant body or both. This combined impact of the corrosion, bacterial activity, chemical reactions, and functional stresses are to be looked at as important factors of implant failure. The findings can be used to explore the possible strategies of research to investigate the biological impact of implant materials.

By |2019-11-23T19:43:14+00:00January 1st, 2019|Other|

Primer on etiology and treatment of progressive/severe periodontitis: A systemic health perspective

Periodontology is an infectious disease-based discipline. The etiopathology of progressive/severe periodontitis includes active herpesviruses, specific bacterial pathogens, and proinflammatory cytokines. Herpesviruses and periodontopathic bacteria may interact synergistically to produce periodontal breakdown, and periodontal herpesviruses may contribute to systemic diseases. The infectious agents of severe periodontitis reside in deep pockets, furcation lesions, and inflamed gingiva, sites inaccessible by conventional (purely mechanical) surgical or nonsurgical therapy but accessible by systemic antibiotic treatment. This brief overview presents an effective anti-infective treatment of severe periodontitis, which includes systemic chemotherapy/antibiotics against herpesviruses (valacyclovir [acyclovir]) and bacterial pathogens (amoxicillin + metronidazole or ciprofloxacin + metronidazole) plus common antiseptics (povidone-iodine and sodium hypochlorite) and select ultrasonic scaling. The proposed treatment can cause a marked reduction or elimination of major periodontal pathogens, is acceptably safe, and can be carried out in minimal time with minimal cost.

By |2021-01-24T20:03:24+00:00January 1st, 2019|Periodontal Disease|

Evidence for Contamination of Silica Microparticles in Advanced Platelet-Rich Fibrin Matrices Prepared Using Silica-Coated Plastic Tubes

Platelet-rich fibrin (PRF) therapy has been widely applied in regenerative dentistry, and PRF preparation has been optimized to efficiently form fibrin clots using plain glass tubes. Currently, a shortage of commercially available glass tubes has forced PRF users to utilize silica-coated plastic tubes. However, most plastic tubes are approved by regulatory authorities only for diagnostic use and remain to be approved for PRF therapy. To clarify this issue, we quantified silica microparticles incorporated into the PRF matrix. Blood samples were collected into three different brands of silica-containing plastic tubes and were immediately centrifuged following the protocol for advanced-PRF (A-PRF). Advanced-PRF-like matrices were examined using a scanning electron microscope (SEM), and silica microparticles were quantified using a spectrophotometer. Each brand used silica microparticles of specific size and appearance. Regardless of tube brands and individual donors, significant, but not accidental, levels of silica microparticles were found to be incorporated into the A-PRF-like matrix, which will be consequently incorporated into the implantation sites. Presently, from the increasing data for cytotoxicity of amorphous silica, we cannot exclude the possibility that such A-PRF-like matrices negatively influence tissue regeneration through induction of inflammation. Further investigation should be performed to clarify such potential risks.

Efficiency of chewable toothbrush in reduction of dental plaque in students.

BACKGROUND:

Besides classical and electrical toothbrushes market offers tooth brushes that can be chewed, like chewing gums. The aim of this study was to show the effectiveness of chewable toothbrush versus a conventional brush in the students’ population.

METHODS:

The prospective study included 346 students. For this research, we used a e-questionnaire for “smart” phones, that students completed outside the dental office. Respondents are divided into two groups: control group used conventional toothbrushes, respondents from the tested group used chewable toothbrush. For assessment of accumulation of the plaque we used TQHI index. For testing statistical hypotheses, the following were used: t-test for two independent samples and analysis of the variance of repeated measurements.

RESULTS:

Before brushing teeth, the average TQHI value for chewable brushes is 2.8 ± 0.3, while conventional is 2.7 ± 0.3, which is not a statistically significant difference (p = 0.448). After brushing teeth, the average TQHI value for chewable brushes is 2.0 ± 0.1, while conventional 2.0 ± 0.3, which is also not statistically significant (p = 0.729). Observing the index of the plaque values on the tooth surfaces in the upper jaw, in both groups, there was a statistically significant change in the amount of plaque in time (p < 0.001). There is a statistically significant interaction between groups and changes in the amount of plaque in the observed period (p = 0.013).

CONCLUSIONS:

The fact that there is no significant difference in the effectiveness of the tested brushes indicates the benefits of using chewable toothbrushes in order to reduce plaque, primarily in the inability to use conventional brushes.

Periodontal Pathogens as Risk Factors of Cardiovascular Diseases, Diabetes, Rheumatoid Arthritis, Cancer, and Chronic Obstructive Pulmonary Disease—Is There Cause for Consideration?

Cardiovascular diseases, chronic obstructive pulmonary diseases, diabetes, rheumatoid arthritis, and cancer are the most common noncommunicable diseases (NCDs). These NCDs share risk factors with periodontal disease (PD), a preventable risk factor linked to lifestyle. The discussion regarding the association between these chronic diseases is more complex. There is still a significant knowledge gap particularly of the causal relationship between PD and NCDs. In this paper, we present fundamental knowledge of the mechanisms and roles of putative periodontal bacteria to gather several hypotheses, evidence that clinical studies thus far have not produced. Although the causal hypotheses are not yet clearly established on a biological basis, prevention and prophylactic measures are recommended to prevent even the possibility of such potential risk factors.

Improved oral hygiene care is associated with decreased risk of occurrence for atrial fibrillation and heart failure: A nationwide population-based cohort study.

AIMS:

Poor oral hygiene can provoke transient bacteremia and systemic inflammation, a mediator of atrial fibrillation and heart failure. This study aims to investigate association of oral hygiene indicators with atrial fibrillation and heart failure risk in Korea.

METHODS:

We included 161,286 subjects from the National Health Insurance System-Health Screening Cohort who had no missing data for demographics, past history, or laboratory findings. They had no history of atrial fibrillation, heart failure, or cardiac valvular diseases. For oral hygiene indicators, presence of periodontal disease, number of tooth brushings, any reasons of dental visit, professional dental cleaning, and number of missing teeth were investigated.

RESULTS:

During median follow-up of 10.5 years, 4911 (3.0%) cases of atrial fibrillation and 7971 (4.9%) cases of heart failure occurred. In multivariate analysis after adjusting age, sex, socioeconomic status, regular exercise, alcohol consumption, body mass index, hypertension, diabetes, dyslipidemia, current smoking, renal disease, history of cancer, systolic blood pressure, blood and urine laboratory findings, frequent tooth brushing (≥3 times/day) was significantly associated with attenuated risk of atrial fibrillation (hazard ratio: 0.90, 95% confidence interval (0.83-0.98)) and heart failure (0.88, (0.82-0.94)). Professional dental cleaning was negatively (0.93, (0.88-0.99)), while number of missing teeth ≥22 was positively (1.32, (1.11-1.56)) associated with risk of heart failure.

CONCLUSION:

Improved oral hygiene care was associated with decreased risk of atrial fibrillation and heart failure. Healthier oral hygiene by frequent tooth brushing and professional dental cleaning may reduce risk of atrial fibrillation and heart failure.

By |2020-02-02T19:06:46+00:00January 1st, 2019|Other|

3D-Imaging of Whole Neuronal and Vascular Networks of the Human Dental Pulp via CLARITY and Light Sheet Microscopy.

Direct visualization of the spatial relationships of the dental pulp tissue at the whole-organ has remained challenging. CLARITY (Clear Lipid-exchanged Acrylamide Tissue hYdrogel) is a tissue clearing method that has enabled successful 3-dimensional (3D) imaging of intact tissues with high-resolution and preserved anatomic structures. We used CLARITY to study the whole human dental pulp with emphasis on the neurovascular components. Dental pulps from sound teeth were CLARITY-cleared, immunostained for PGP9.5 and CD31, as markers for peripheral neurons and blood vessels, respectively, and imaged with light sheet microscopy. Visualization of the whole dental pulp innervation and vasculature was achieved. Innervation comprised 40% of the dental pulp volume and the vasculature another 40%. Marked innervation morphological differences between uni- and multiradicular teeth were found, also distinct neurovascular interplays. Quantification of the neural and vascular structures distribution, diameter and area showed that blood vessels in the capillary size range was twice as high as that of nerve fibers. In conclusion whole CLARITY-cleared dental pulp samples revealed 3D-morphological neurovascular interactions that could not be visualized with standard microscopy. This represents an outstanding tool to study the molecular and structural intricacies of whole dental tissues in the context of disease and treatment methods.

Conflicts of interest between the sugary food and beverage industry and dental research organisations: time for reform.

Prevention of dental caries (tooth decay), one of the most common chronic diseases globally,1 requires the global implementation of WHO’s guideline on sugars intake.2,3 WHO recommends that individuals consume less than 10% of total energy intake from free sugars and that intake below 5% would be beneficial.3 The global dental research community, as the Lancet oral health Series1,2 argues, has an important role in the implementation
of the WHO guideline by promoting research on public health and dietary interventions, among other actions. However, dental research activities have not focused on sugars for many years. To remedy this, the European Organisation for Caries Research (ORCA) and the European Association of Dental Public Health (EADPH) organised a joint symposium on sugars in 2015 to stimulate new research.4 The same year, the American Dental Association urged the US National Institute of Dental and Craniofacial Research (NIDCR) to increase research on sugars and oral health.5

By |2020-01-19T19:07:00+00:00January 1st, 2019|Other|
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