Coronavirus disease (COVID-19) transmission through aerosols in restorative and endodontic practice: Strategies for prevention.

Rapid spread of coronavirus disease 2019 (COVID-19) in several countries of the world has created a state of public health emergency. COVID-19 is principally a respiratory disease, and the virus is present in respiratory secretions. Oral health-care professionals are susceptible to being infected with the disease since they work in close proximity to patient's face and oral cavity for long period of time. Restorative dentists and endodontists play a significant role in delivering "urgent" or "emergency" dental care to patients. Occupational Safety and Health Administration has categorized dentists performing aerosol-generating treatment procedures at "very high exposure risk" whereas the dentists not performing aerosol-generating procedures at "high exposure risk." Most of the restorative and endodontic treatment procedures involve generation of aerosols. Owing to the possibility of transmission of virus through aerosols, these procedures may transmit the disease to clinician or other patients. A comprehensive search of literature was conducted with the help of PubMed/MEDLINE and Scopus databases using a combination of terms, "COVID-19," "severe acute respiratory syndrome coronavirus 2," "aerosols," "restorative dentistry," and "endodontics." Along with universal precautions, some additional precautions need to be taken to prevent such transmission and cross-infection. This article reviews the research evidence about the role of aerosols in the transmission of COVID-19 and various measures which should be implemented during restorative and endodontic practice for the prevention of such transmission.

Résumé La propagation rapide de la maladie à coronavirus 2019 (COVID-19) dans plusieurs pays du monde a créé un état d'urgence de santé publique. Le COVID-19 est principalement une maladie respiratoire et le virus est présent dans les sécrétions respiratoires. Les professionnels de la santé bucco-dentaire sont susceptibles d'être infectés par la maladie, car ils travaillent à proximité du visage et de la cavité buccale du patient pendant une longue période. Les dentistes restaurateurs et les endodontistes jouent un rôle important dans la prestation de soins dentaires "urgents" ou "d'urgence" aux patients. L'Occupational Safety and Health Administration (OSHA) a classé les dentistes effectuant des procédures de traitement générant des aérosols à "Risque très élevé", tandis que les dentistes n'effectuant pas de procédures générant des aérosols à "Risque élevé d'exposition". La plupart des procédures de traitement de restauration et d'endodontie impliquent la génération d'aérosols. En raison de la possibilité de transmission du virus par les aérosols, ces procédures peuvent transmettre la maladie au clinicien ou à d'autres patients. Une recherche complète de la littérature a été menée à l'aide des bases de données PubMed/MEDLINE et Scopus en utilisant une combinaison de termes, "COVID-19", "SARS-CoV-2", "aérosols", "dentisterie restauratrice" et "endodontie". Outre les précautions universelles, certaines précautions supplémentaires doivent être prises pour prévenir une telle transmission et une infection croisée. Cet article passe en revue les preuves de la recherche sur le rôle des aérosols dans la transmission de COVID-19 et diverses mesures qui devraient être mises en œuvre lors de la pratique réparatrice et endodontique pour la prévention d'une telle transmission. Mots-clés: COVID-19, aérosols, dentisterie restauratrice, endodontie, évacuation à haut volume.

Comparative analysis of cleaning ability of three nickel-titanium rotary systems: ProTaper universal, K3 and Mtwo: An in vitro scanning electron microscopic study.

BACKGROUND: Endodontic instruments including the nickel-titanium (NiTi) instruments produce debris and smear layer during instrumentation. The study was carried out to evaluate and compare the cleaning effectiveness of root canal preparation using three different rotary NiTi instrumentation systems - ProTaper Universal, K3 and Mtwo by means of scanning electron microscopy (SEM). METHODS: Thirty-six freshly extracted permanent mandibular molars were randomly divided into four groups: ProTaper Universal, K3, Mtwo system and control group. The mesiobuccal canal was cleaned and shaped with rotary instruments. The intracanal irrigant used after each instrument was 3 mL of 3% sodium hypochlorite (NaOCl). After the cleaning and shaping was completed, a 1-min 17% ethylenediaminetetraacetic acid rinse was followed by a final NaOCl rinse. All samples were decoronated. Mesial roots were sectioned buccolingually and examined under SEM at 500× magnification in three areas of root canal. Canal walls were quantitatively evaluated using a five-score evaluation scale. Statistical analysis was done using Kruskal-Wallis test, Fisher's exact test and weighted kappa. RESULTS: Completely clean canals were not found in any of the groups. The mean value of debris score for ProTaper, K3 and Mtwo was 2.35, 2.41 and 2.22 respectively. There was no statistically significant difference between the three tested groups (P = 0.237). The apical thirds of the canal was found to be significantly less clean than coronal and middle thirds irrespective of the system used. CONCLUSIONS: There was no statistically significant difference between the three tested groups - ProTaper, K3 and Mtwo in cleaning different regions of the canal - coronal, middle and apical.

Management of 'labial' type of dens invaginatus: A rare case report.

Dens invaginatus is a developmental anomaly resulting in an infolding of the enamel organ into the dental papilla prior to calcification of the dental tissues. The invagination predisposes the tooth for the development of dental caries. Conventional radiographs do not provide detailed information concerning the three-dimensional image, which would help the clinician in making a confirmatory diagnosis and planning the treatment before undertaking the actual treatment. This report describes a case where Oehlers type II dens invaginatus was diagnosed with the help of spiral computed tomography. The locations of the primary root canal and the invagination were assessed from spiral computed tomography scan images. Usually, the invagination is present on palatal/lingual side. However, in this case, the invagination was unusually located on labial side, which has yet not been reported. The tooth also showed certain unusual morphological features.