Possible aerosol transmission of COVID-19 and special precautions in dentistry.

Since its emergence in December 2019, corona virus disease 2019 (COVID-19) has impacted several countries, affecting more than 90 thousand patients and making it a global public threat. The routes of transmission are direct contact, and droplet and possible aerosol transmissions. Due to the unique nature of dentistry, most dental procedures generate significant amounts of droplets and aerosols, posing potential risks of infection transmission. Understanding the significance of aerosol transmission and its implications in dentistry can facilitate the identification and correction of negligence in daily dental practice. In addition to the standard precautions, some special precautions that should be implemented during an outbreak have been raised in this review.

Autotransplantation of third molars with completely formed roots to replace compromised molars with the computer-aided rapid prototyping.

OBJECTIVE: To describe a method to fabricate donor tooth replica to assist surgeons in preparation of recipient socket during tooth autotransplantation. MATERIALS AND METHODS: A total of 28 compromised molars in 27 patients were transplanted with third molars using computer-aided rapid prototyping (CARP) technique. Surgery time and extra-alveolar time were documented. Postoperatively, the distance between cervix of transplanted tooth and the alveolar wall was measured. The degree of postoperative pain experienced was assessed with visual analog scale at day 1, 3, and 7. RESULTS: From 28 clinical cases, the average extra-alveolar time and surgery time were 2.5 minutes (±1.3) and 44 minutes (±6.8), respectively. Postoperatively, the average distance between cervix of transplanted tooth and the alveolar wall was 0.87 mm (±0.15) at the mesial-cervix, 0.95 mm (±0.17) at the distal-cervix, 0.88 mm (±0.18) at the buccal-cervix, and 0.95 mm (±0.13) at the lingual-cervix. The value of visual analog scale score significantly decreased from day 1 to day 3. CONCLUSIONS: CARP is a reliable technique for fabrication of tooth like surgical replicas in conventional autotransplantation. CLINICAL SIGNIFICANCE: CARP technique minimized extra-oral time, reduced iatrogenic damage, and consequently increased the survival rate of tooth autotransplantation.

DKK1 rescues osteogenic differentiation of mesenchymal stem cells isolated from periodontal ligaments of patients with diabetes mellitus induced periodontitis.

Multiple studies have shown that diabetes mellitus is an established risk factor for periodontitis. Recently mesenchymal stem cells derived from periodontal ligament (PDLSCs) have been utilized to reconstruct tissues destroyed by chronic inflammation. However, impact of periodontitis with diabetes mellitus on PDLSCs and mechanisms mediating effects of complex microenvironments remain poorly understood. In this study, we found multiple differentiation potential of PDLSCs from chronic periodontitis with diabetes mellitus donors (D-PDLSCs) was damaged significantly. Inhibition of NF-κB signaling could rescue osteogenic potential of PDLSCs from simple chronic periodontitis patients (P-PDLSCs), whereas did not promote D-PDLSCs osteogenesis. In addition, we found expression of DKK1 in D-PDLSCs did not respond to osteogenic signal and decreased osteogenic potential of D-PDLSCs treated with DKK1 could be reversed. To further elucidate different character between P-PDLSCs and D-PDLSCs, we treated PDLSCs with TNF-α and advanced glycation end products (AGEs), and find out AGEs which enhance effect of TNF-α in PDLSCs might mediate special personality of D-PDLSCs. The adverse effect of AGEs in PDLSCs could be reversed when PDLSCs were treated with DKK1. These results suggested DKK1 mediating WNT signaling might be a therapy target to rescue potential of PDLSCs in periodontitis with diabetes mellitus.