Indoor Air Quality Evaluation Using Mechanical Ventilation and Portable Air Purifiers in an Academic Dentistry Clinic during the COVID-19 Pandemic in Greece.

The coronavirus disease 2019 (COVID-19), which is mainly transmitted through droplets without overlooking other sources of transmission, rendered attention on the air quality in indoor areas and more specifically in healthcare settings. The improvement of indoor air quality (IAQ) is ensured by frequent changes of the air that must be carried out in healthcare areas and with assistance from special devices that undertake the filtration of the air and its purification through special filters and lamps. In this research, the performance of air purifiers is assessed in terms of the limitation of PM2.5, PM10, VOCs and CO2 in a postgraduate clinic of the Dentistry School of the National and Kapodistrian University of Athens in parallel with mechanical ventilation. Our findings indicate that the use of mechanical ventilation plays a key role on the results, retaining good IAQ levels within the clinic and that air purifiers show a positive impact on IAQ by mainly reducing the levels of PM2.5 and secondly of TVOC.

Preparing dental schools to refunction safely during the COVID-19 pandemic: an infection prevention and control perspective.

In late 2019 a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in China and spread throughout the world over a short period of time causing a pandemic of a respiratory disease named coronavirus disease 2019 (COVID-19). SARS-CoV-2 is easily transmitted from person to person through respiratory droplets and direct contact. The scarce available data indicate that dental healthcare personnel are at increased risk for acquisition of infection. Following the lockdown lifting, dental schools should be prepared to refunction safely and provide essential educational and healthcare services while protecting their students, patients, and personnel. The generation of aerosols in dental practice, in association with the high-transmissibility of SARS-CoV-2 through aerosol-generation procedures, the simultaneous provision of dental services to patients in the same areas, and the fact that asymptomatic and pre-symptomatic infected persons may transmit the virus, render the implementation of specific infection prevention and control measures imperative for dental schools. Herein we review the few evidence-based data available to guide infection prevention and control measures for COVID-19 in dental schools.

Oxytalan-positive peripheral ossifying fibromas express runt-related transcription factor 2, bone morphogenetic protein-2, and cementum attachment protein. An immunohistochemical study.

BACKGROUND: The peripheral ossifying fibroma (POF) represents one of the most common lesions of the periodontal tissues that may originate from the gingival soft tissues, the periosteum, or the periodontal ligament. AIM: To investigate the immunohistochemical expression of runt-related transcription factor 2 (Runx-2), bone morphogenetic protein-2 (BMP-2), and cementum attachment protein (CAP) in oxytalan-positive POF, to establish the use of POF as an in vivo model for the study of the periodontal ligament. MATERIALS AND METHODS: Thirty tumors that presented clinical and histologic features of POF, as well as oxytalan fibers, were included in the study. Immunohistochemical expression of Runx-2, BMP-2, and CAP was evaluated by light microscopy. RESULTS: Runx-2, BMP-2, and CAP were abundantly expressed by POFs; 22 of 30 tumors expressed positive staining for Runx-2, twenty-six tumors for BMP-2, and twenty-five tumors for CAP. The expression of Runx-2 was abundant in POFs where bone was histologically present (P = 0.04) and of BMP-2 in POFs where dystrophic calcifications were present (P = 0.03). CONCLUSION: It is suggested that oxytalan-positive POFs, purportedly originating from the periodontal ligament, express molecules that are specific to bone and cementum (Runx-2, BMP-2), or cementum only (CAP). Thus, the cell populations present in the lesion belong to the mineralized-tissue-forming cell lineages, the cementoblastic or osteoblastic lineage.

Endothelial cells of oral pyogenic granulomas express eNOS and CD105/endoglin: an immunohistochemical study.

BACKGROUND: The pyogenic granuloma (PG) is a common localized hyperplastic lesion of the oral cavity. The purpose of the present study was to investigate the immunohistochemical expression of endothelial nitric oxide synthases (eNOS) and CD105/endoglin in oral PGs, to evaluate their involvement in the angiogenetic pathways of the lesion. MATERIALS AND METHODS: Ninety-three PGs were included in the study. Sixteen tumors were further sub-classified as pregnancy tumors (PT) and seventeen as pyogenic granulomas with fibrosis (PGFM). Immunohistochemical expression of eNOS and CD105/endoglin was quantified by computerized image analysis with a semi-automated system. Percentage of staining and number of objects (positive vessels) were recorded for each case. RESULTS: Intense eNOS expression was seen in 92 of 93 lesions. A statistically significant association was found between eNOS percentage of staining/eNOS positive vascular spaces (objects) and age of the patients (9% increase per decade of life). Approximately 40% less eNOS positive objects were recorded in PGFM compared with PGs. Intense membranous CD105/endoglin expression was seen in all cases. The percentage of CD105/endoglin staining was statistically increased in PGs compared with PT. Approximately 40% less CD105/endoglin objects were found in PGFM compared with PGs; 56% more CD105/endoglin objects were found in tongue lesions, compared with gingival lesions. There was no statistically significant correlation considering percentage of staining and number of objects between CD105/endoglin and eNOS. CONCLUSIONS: It is suggested that eNOS and CD105/endoglin are involved in the angiogenetic pathways of PG.

Severe periodontitis in a patient with hyperoxaluria and oxalosis: a case report and review of the literature.

BACKGROUND: Hyperoxaluria is a metabolic disease with excessive urinary oxalate excretion that can be primary or secondary. Hyperoxaluria can result in chronic renal disease and renal failure. Calcium oxalate crystals can be deposited in oral tissues, and the disease can be associated with severe periodontitis and tooth loss. METHODS: The periodontal condition of a 38-year-old patient with a diagnosis of hyperoxaluria and end-stage renal disease is presented. The patient's periodontal status was monitored over a period of several weeks, and extracted teeth were submitted for histopathologic evaluation. RESULTS: The patient was diagnosed with generalized severe periodontitis and external root resorption. Initial periodontal treatment consisting of oral-hygiene instructions and scaling and root planing was performed. However, despite an initial decrease of soft tissue inflammation, the patient's periodontal condition deteriorated, and eventually, all teeth had to be extracted. The deposition of calcium oxalate crystals in the periodontal tissues was confirmed histologically. CONCLUSIONS: Long-standing hyperoxaluria can be associated with severe periodontitis and external root resorption resulting in tooth loss. The pathogenetic mechanisms of hard tissue destruction are still unclear.