Pros and Cons of CAD/CAM Technology for Infection Prevention in Dental Settings during COVID-19 Outbreak.

The purpose of this commentary is to update the evidence reported in our previous review on the advantages and limitations of computer-aided design/computer-aided manufacturing technology in the promotion of dental business, as well as to guarantee patient and occupational safety. The COVID-19 pandemic led to an unprecedented focus on infection prevention; however, waves of COVID-19 follow one another, asymptomatic cases are nearly impossible to identify by triage in a dental setting, and the effectiveness of long-lasting immune protection through vaccination remains largely unknown. Different national laws and international guidelines (mainly USA-CDC, ECDC) have often brought about dissimilar awareness and operational choices, and in general, there has been very limited attention to this technology. Here, we discuss its advantages and limitations in light of: (a) presence of SARS-CoV-2 in the oral cavity, saliva, and dental biofilm and activation of dormant microbial infections; (b) the prevention of SARS-CoV-2 transmission by aerosol and fomite contamination; (c) the detection of various oral manifestations of COVID-19; (d) specific information for the reprocessing of the scanner tip and the ward from the manufacturers.

Dental Trauma at a University Dental Clinic in Milan including the SARS-CoV-2 Period.

The aim of this study i.e., is to present the distribution of traumatic dental injuries (TDI) in 306 patients registered at the Unit of Dental Emergencies at a University Dental Clinic in Milan, Italy, between June 2019 and May 2021. This time frame includes the beginning of the SARS-CoV-2 pandemic. Information regarding age, gender, number and type of injured teeth, type of traumatic injury, and data on where or how the injury happened were recorded. Seventy-nine percent of patients can be classified as pediatric (under 14 years old), and in all age groups, male patients were found to be more susceptible (1.6:1). A total of 480 teeth were involved, 59% of which were deciduous, and 41% permanent. The most affected teeth in both dentitions were upper central incisors. In deciduous teeth, periodontal lesions were more common, whereas in permanent dentitions, dental fractures were diagnosed more often. Most data found in this study confirms the results found in the literature. The biggest difference, due to changes in daily routine during the SARS-CoV-2 pandemic, can be found by analyzing the incidence and etiology. As a matter of fact, there was a decrease in school accidents, whereas domestic falls remained constant.

TMPRSS2, a SARS-CoV-2 internalization protease is downregulated in head and neck cancer patients.

BACKGROUND: SARS-coronavirus-2 enters host cells through binding of the Spike protein to ACE2 receptor and subsequent S priming by the TMPRSS2 protease. We aim to assess differences in both ACE2 and TMPRSS2 expression in normal tissues from oral cavity, pharynx, larynx and lung tissues as well as neoplastic tissues from the same areas. METHODS: The study has been conducted using the TCGA and the Regina Elena Institute databases and validated by experimental model in HNSCC cells. We also included data from one COVID19 patient who went under surgery for HNSCC. RESULTS: TMPRSS2 expression in HNSCC was significantly reduced compared to the normal tissues. It was more evident in women than in men, in TP53 mutated versus wild TP53 tumors, in HPV negative patients compared to HPV positive counterparts. Functionally, we modeled the multivariate effect of TP53, HPV, and other inherent variables on TMPRSS2. All variables had a statistically significant independent effect on TMPRSS2. In particular, in tumor tissues, HPV negative, TP53 mutated status and elevated TP53-dependent Myc-target genes were associated with low TMPRSS2 expression. The further analysis of both TCGA and our institutional HNSCC datasets identified a signature anti-correlated to TMPRSS2. As proof-of-principle we also validated the anti-correlation between microRNAs and TMPRSS2 expression in a SARS-CoV-2 positive HNSCC patient tissues Finally, we did not find TMPRSS2 promoter methylation. CONCLUSIONS: Collectively, these findings suggest that tumoral tissues, herein exemplified by HNSCC and lung cancers might be more resistant to SARS-CoV-2 infection due to reduced expression of TMPRSS2. These observations may help to better assess the frailty of SARS-CoV-2 positive cancer patients.