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About Lechner J, von Baehr V, Zimmermann B.

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So far Lechner J, von Baehr V, Zimmermann B. has created 991 blog entries.

Osteonecrosis of the jaw beyond bisphosphonates: are there any unknown local risk factors?

Unresolved wound healing at extraction sites, where wisdom teeth have been removed for example, may contribute to the pathogenesis of BRONJ. With IV BP administration, persisting AIOJ/BMD/FDOJ areas may be behind BRONJ development. Therapeutic recommendations include IV BP administration following AIOJ/BMD/FDOJ diagnosis and surgical removal of ischemic areas. BPs should not be regarded as the only cause of osteonecrosis.

By |2022-07-12T18:39:57+00:00January 1st, 2021|Other|

Methylmercury-induced cytotoxicity and oxidative biochemistry impairment in dental pulp stem cells: the first toxicological findings.

Background: Methylmercury (MeHg) is a potent toxicant able to harm human health, and its main route of contamination is associated with the consumption of contaminated fish and other seafood. Moreover, dental amalgams are also associated with mercury release on human saliva and may contribute to the accumulation of systemic mercury. In this way, the oral cavity seems to be the primary location of exposure during MeHg contaminated food ingestion and dental procedures but there is a lack of literature about its effects on dental tissues and the impact of this toxicity on human health. In this way, this study aimed to analyze the effects of different doses of MeHg on human dental pulp stem cells after short-term exposure.

Methods: Dental pulp stem cells from human exfoliated deciduous teeth (SHED) were treated with 0.1, 2.5 and 5 µM of MeHg during 24 h. The MeHg effects were assessed by evaluating cell viability with Trypan blue exclusion assay. The metabolic viability was indirectly assessed by MTT reduction assay. In order to evaluate an indicative of antioxidant defense impairment, cells exposed to 0.1 and 5 µM MeHg were tested by measuring glutathione (GSH) level.

Results: It was observed that cell viability decreased significantly after exposure to 2.5 and 5 µM of MeHg, but the metabolic viability only decreased significantly at 5 µM MeHg exposure, accompanied by a significant decrease in GSH levels. These results suggest that an acute exposure of MeHg in concentrations higher than 2.5 µM has cytotoxic effects and reduction of antioxidant capacity on dental pulp stem cells.

Transmission potential of SARS-CoV-2 in viral shedding observed at the University of Nebraska Medical Center.

Lack of evidence on SARS-CoV-2 transmission dynamics has led to shifting isolation guidelines between airborne and droplet isolation precautions. During the initial isolation of 13 individuals confirmed positive with COVID-19 infection, air and surface samples were …

Comparative dynamic aerosol efficiencies of three emergent coronaviruses and the unusual persistence of SARS-CoV-2 in aerosol suspensions

The emergent coronavirus, designated severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is a zoonotic pathogen that has demonstrated remarkable transmissibility in the human population and is the etiological agent of a current global pandemic called COVID-191. We measured the dynamic (short-term) aerosol efficiencies of SARS-CoV-2 and compared the efficiencies with two other emerging coronaviruses, SARS-CoV (emerged in 2002) and Middle Eastern respiratory syndrome CoV (MERS-CoV; emerged starting in 2012).

Community water fluoridation perceptions and practice in the United States: challenges in governance and implementation.

The primary objective of this research is to reveal potential challenges in achieving the finalized water fluoridation recommendation made by the Federal Water Fluoridation Panel in the United States (U.S.) with data extracted from consumer confidence reports. A secondary objective is to understand community water systemmanager’s perceptions of and ability to meet this new standard using a survey instrument. Mean fluoridationlevels are above the recommended level. The confidence interval does not capture the nationally recommended 0.7 mg/L. The t-test revealed two statistically significant results: that the sample mean is not equal to 0.7 mg/L and that the sample mean higher than 0.7 mg/L. Respondents felt engaged in the policy process, but preferred state over federal policymaking. There is evidence that the optimal fluoridation level may not have been reached by water systems and that some water systems are under-fluoridating, while others are over-fluoridating. Several large water systems and pockets across the U.S. are not practicing artificial water fluoridation which reduces theeffectiveness of this policy. Regular engagement by states with water system managers and feedback from water management professionals could be encouraged to better understand local constraints in meeting the federal recommendation.

By |2021-01-31T00:05:27+00:00January 1st, 2020|Fluoride|

Air, surface environmental, and personal protective equipment contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a symptomatic patient

This study documents results of SARS-CoV-2 polymerase chain reaction (PCR) testing of environmental surfaces and personal protective equipment surrounding 3 COVID-19 patients in isolation rooms in a Singapore hospital.

Brain abscesses and intracranial empyema due to dental pathogens: Case series.

Introduction: Spontaneous brain abscess and intracranial empyema are rare but life-threatening diseases. They can result from potential complications of oral chronic infections. Given the similarity between most of the germs commonly found both in cerebral abscess and in oral cavity and its anatomic proximity, the oral cavity represents a major source of cerebral infections.

Presentation of cases: We report here a series of seven cases of intracranial abscesses and empyema due to dental pathogens that occurred in the neurosurgery department of our institute. Five of those seven cases were then cared in the oral surgery department of our institute.

Discussion: Bacteriological examination of the brain abscesses identified an oral commensal bacterium belonging to streptococci group in six patients (85.7%) and Porphyromonas Gingivalis, a pathogen oral germ involved in periodontal diseases in the seventh patient. For all patients examined, oral status and oral health were poor or moderate with the presence of dental caries, missing teeth and abundant dental plaque. Except the oral cavity, no other front door or infectious site were found.

Conclusion: This rare series of cases highlights the importance of systematically explore the oral cavity in presence of intracranial infection and to radically eradicate the potential infectious foci.

The impact of the COVID-19 epidemic on the utilization of emergency dental services

Background/purpose: To assess how the current COVID-19 epidemic influenced peoples’ utilization of emergency dental services in Beijing, China.

Methods: The first-visit patients seeking emergency dental services before or at the beginning of the COVID-19 epidemic were retrieved. Their demographic characteristics and the reasons for visiting were recorded and analyzed.

Results: There were 2,537 patients involved in this study. Thirty-eight percent fewer patients visited the dental urgency at the beginning of the COVID-19 epidemic than before. The distribution of dental problems has changed significantly. The proportion of dental and oral infection raised from 51.0% of pre-COVID-19 to 71.9% during COVID-19, and dental trauma decreased from 14.2% to 10.5%. Meanwhile, the non-urgency cases reduced to three-tenths of pre-COVID-19.

Conclusion: Within the limitation of this study, the COVID-19 epidemic had a strong influence on the utilization of emergency dental services.

By |2020-12-31T00:06:50+00:00January 1st, 2020|Covid19|

Controversy: The evolving science of fluoride: when new evidence doesn’t conform with existing beliefs.

Over the past 75 years, health authorities have declared that community water fluoridation-a practice that reaches over 400 million worldwide-is safe. Yet, studies conducted in North America examining the safety of fluoride exposure in pregnancy were nonexistent. When a Canadian study reported that higher fluoride exposure in pregnant women was associated with lower IQ scores in young children, critics attacked the methodology of the study and discounted the significance of the results. Health authorities continued to conclude that fluoride is unequivocally safe, despite four well-conducted studies over the last 3 years consistently linking fluoride exposure in pregnancy with adverse neurodevelopmental effects in offspring. We describe the challenges of conducting fluoride research and the overt cognitive biases we have witnessed in the polarized fluoride debate. The tendency to ignore new evidence that does not conform to widespread beliefs impedes the response to early warnings about fluoride as a potential developmental neurotoxin. Evolving evidence should inspire scientists and health authorities to re-evaluate claims about the safety of fluoride, especially for the fetus and infant for whom there is no benefit.

By |2021-01-26T00:45:20+00:00January 1st, 2020|Fluoride|
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