Reopening Oral Health Services during the COVID-19 Pandemic through a Knowledge Exchange Coalition.

BACKGROUND: The COVID-19 novel coronavirus closed oral health care in Nova Scotia (NS) Canada in March 2020. Preparing for a phased reopening, a knowledge exchange coalition (representing government, academia, hospitals, oral health professions, and regulators) developed return-to-work (RTW) guidelines detailing the augmentation of standard practices to ensure safety for patients, oral health care providers (OHPs), and the community. Using online surveys, this study explored the influence of the RTW guidelines and related education on registered NS OHPs during a phased return to work. METHODS: Dissemination of R2W guidelines included website or email communiques and interdisciplinary education webinars that coincided with 2 RTW phases approved by the government. Aligned with each phase, all registered dentists, dental hygienists, and dental assistants were invited to complete an online survey to gauge the influence of the coalition-sponsored education and RTW guidelines, confidence, preparedness, and personal protective equipment use before and after the pandemic. RESULTS: Three coalition-sponsored multidisciplinary webinars hosted 3541 attendees prior to RTW. The response to survey 1 was 41% (881/2156) and to survey 2 was 26% (571/2177) of registrants. Survey 1 (82%) and survey 2 (89%) respondents "agreed/strongly agreed" that R2W guidelines were a primary source for guiding return to practice, and most were confident with education received and had the skills needed to effectively treat patients during the COVID-19 pandemic. Confidence and preparedness improved in survey 2. Gowns/lab coat use for aerosol-generating procedures increased from 26% to 93%, and the use of full face shields rose from 6% to 93% during the pandemic. CONCLUSIONS: A multistakeholder coalition was effective in establishing and communicating comprehensive guidelines and web-based education to ensure unified reintegration of oral health services in NS during a pandemic. This multiorganizational cooperation lay the foundation for responses to subsequent waves of COVID-19 and may serve as an example for collaboratively responding to future public health threats in other settings. KNOWLEDGE TRANSFER STATEMENT: The return-to-work strategy that was developed, disseminated, and assessed through this COVID-19 knowledge exchange coalition will benefit oral health practitioners, professional regulators, government policy makers, and researchers in future pandemic planning.

Preventing transmission of bloodborne viruses from infected healthcare workers to patients: Summary of a new Canadian Guideline.

BACKGROUND: Although it is well documented that bloodborne viruses (BBVs), including human immunodeficiency virus (HIV), hepatitis C virus (HCV) and hepatitis B virus (HBV) have been transmitted from patients to healthcare workers (HCWs), there has also been reported transmission from HCWs to patients during the provision of health care. With remarkable progress in infection prevention, diagnosis tools, treatment regimens and major improvements in guideline development methodology, there was a need to develop an evidence-based guideline to replace the 1998 Canadian consensus document for managing HCWs infected with BBVs. PURPOSE: This article summarizes the Canadian Guideline on the Prevention of Transmission of Bloodborne Viruses from Infected Healthcare Workers in Healthcare Settings. METHODS: A Guideline Development Task Group was established and key questions developed to inform the guideline content. Systematic reviews were conducted to evaluate the risk of HCW-to-patient transmission of HIV, HCV and HBV. Environmental scans were used to provide information on Expert Review Panels, disclosure of a HCW's serologic status and lookback investigations. Federal, provincial and territorial partners and key stakeholder organizations were consulted on the Guideline. RESULTS: The risk of HCW-to-patient BBV transmission was found to be negligible, except during exposure-prone procedures, where there is a risk that injury to the HCW may result in exposure of a patient's open tissues to the HCW's blood. Risk of ensuing transmission and the rate of transmission varied by BBV, and were lowest with HIV and highest with HBV. The Guideline provides key content, including recommendations regarding criteria to determine if a procedure is an exposure-prone procedure, management of HCWs infected with a BBV, including considerations for the HCW's fitness for practice, Expert Review Panels, HCW disclosure obligations and right to privacy and lookback investigations. CONCLUSION: This new Guideline provides a pan-Canadian approach for managing HCWs infected with a BBV, with recommendations related to preventing HCW-to-patient transmission of BBVs during the provision of care.

Anomalous mandibular premolars: a mandibular first premolar with three roots and a mandibular second premolar with a C-shaped canal system.

AIM: To describe unusual variations in the root morphology and root canal systems of mandibular first and second premolar teeth extracted for orthodontic reasons. SUMMARY: Normally mandibular first and second premolar teeth have single roots with single canals. A 15-year-old patient presented for orthodontic treatment and two mandibular premolar teeth were examined post-extraction. The mandibular first premolar exhibited three distinct, separate roots and the mandibular second premolar exhibited a C-shaped root canal system. The coronal morphology of each of the mandibular premolars revealed dimensions and anatomy within normal limits. The incidence of a three-rooted mandibular first premolar is approximately 0.2%. KEY LEARNING POINTS: * Thorough clinical and radiographic interpretation is important in recognizing anomalous root and root canal systems. * The most common forms of root and canal systems and its aberrations must be understood to realize variations from normal do occur. * Successful root canal treatment requires an accurate diagnosis of the root canal system using all available aids. * Value of microcomputed tomography in the study of anatomy ex vivo and cone-beam tomography in clinical endodontics of complex premolar cases is increasing.

The diversity and distribution of the predominant ribotypes of Actinomyces naeslundii genospecies 1 and 2 in samples from enamel and from healthy and carious root surfaces of teeth.

The bacterial communities associated with root caries are highly diverse and undergo succession during lesion formation. Consequently, root caries is said to have a polymicrobic etiology, typified by variation in the predominant species among samples from different lesions. Despite the polymicrobic etiology, A. naeslundii genospecies 1 and 2 (previously A. viscosus) have consistently been shown to be associated with root caries in humans; they predominate in some lesions and have been suggested to play a significant role in the disease. Several genetic variants of A. naeslundii are known to be present among the oral A. naeslundii population of an individual. The current study was initiated to explore the possibility that a variant in these A. naeslundii populations had characteristics which made it best fitted to colonize or promote root-surface caries lesions. Using ribotyping to detect variants, we tested the hypothesis that 'a ribotype of A. naeslundii best fitted to the environment would be selected and predominate in the A. naeslundii population of lesions'. Samples of plaque from enamel, normal root surfaces, plaque overlying the lesion, and material from within the lesion were taken from nine patients with soft root caries. The flora from 14 lesions and 9 enamel sites was analyzed on selective and non-selective media, and A. naeslundii genospecies were identified by serology. We ribotyped 972 isolates, showing 54 different patterns. Between 6 and 20 ribotypes were isolated from eight of nine patients. In general, each site from a patient showed a similar distribution of ribotypes. These results do not support the hypothesis and suggest that any phenotypic characters that allow A. naeslundii genospecies 1 and 2 to colonize or contribute to the formation of root-caries lesions are common among strains identified by ribotyping.

Effect of acute acidemia on blood biochemical variables in healthy ponies.

L-Lactic acid and D,L-lactic acid infusion in ponies resulted in metabolic acidosis with high anion gap (AG). Increased AG was explained entirely by increased blood L- and D-lactate concentrations. Hydrochloric acid infusion caused metabolic acidosis with decreased AG. Saline (NaCl) infusion caused mild metabolic acidosis, with no significant change in AG. Plasma K+ concentration was decreased by all types of infusions, with a maximum of 0.50, 0.25, 0.40, 0.50 mmol/L below baseline at the end of infusion in the L-lactic acid-, D,L-lactic acid-, HCl-, and NaCl-infused ponies, respectively. Only hydrochloric acid had a tendency to increase plasma K+ concentration. Hypophosphatemia developed in NaCl- and HCl-infused ponies, but not in the D,L-lactic acid-infused ponies. Serum inorganic phosphate concentration in L-lactic acid-infused ponies increased initially, but was significantly (P less than 0.05) lower than values in the other ponies at 4 hours after onset of infusion. In ponies, the effect of acidemia on plasma K+ and serum inorganic phosphate concentrations was similar to that reported for other species. Changes were small in magnitude and depended on the nature of the acid anion. Results indicate that large changes in plasma K+ and serum inorganic phosphate concentrations during acidosis are probably not a direct result of acidemia.

Blood biochemical response to sodium bicarbonate infusion during sublethal endotoxemia in ponies.

Hypertonic NaHCO3 infusion caused blood volume expansion, increased blood bicarbonate concentration, and delayed the onset of hypophosphatemia in ponies with endotoxemia. However, NaHCO3 infusion did not normalize blood pH, and it increased blood L-lactate concentration, and caused hypokalemia, hypernatremia, and hyperosmolality. The deleterious effects of NaHCO3 infusion in endotoxemia ponies outweighed the beneficial effects. The role of hypertonic NaHCO3 given IV for treatment of endotoxemia in equids must be reevaluated.

The effect of pH on the sensitivity of species of Lactobacillus to chlorhexidine and the antibiotics minocycline and spiramycin.

The purpose of this study was to determine the sensitivity of a range of Lactobacillus species to chlorhexidine, Minocycline, and Spiramycin, at a range of pH from 5.0 to 7.4. Strains of Streptococcus were also tested for their sensitivity to chlorhexidine, as a comparison between the genera. There were both inter- and intra-species variations in the sensitivity of these strains to chlorhexidine. The strains tested were sensitive at pH 6.7 to the following levels of chlorhexidine (micrograms/mL): L. casei (6 strains), 10-60; L. plantarum (4 strains), 40; L. fermentum (13 strains), 2-20; L. brevis (1 strain), 10; and L. acidophilus (3 strains), 10-60. The Streptococcus species were sensitive to 1-4 micrograms/mL (13 strains); 4-10 micrograms/mL (3 strains); and 10-20 micrograms/mL (2 strains). One strain was able to survive 20 micrograms/mL. Chlorhexidine was found to be less effective at lower pH levels. The following examples show sensitivity (micrograms/mL) at pH 6.5 followed by sensitivity at pH 5.0: L. casei (ATCC 15008), 40,60; L. plantarum (CH 374), 40,100; L. fermentum (CH 324) 10,40; L. acidophilus (ATCC 4356), 10,40; and S. mutans (BM 52), 2,2. All of the strains of Lactobacillus tested with Spiramycin were resistant at pH 5.0. Minocycline was less affected by changes in pH, but at pH 7.4 Lactobacillus strains were more resistant to Minocycline as compared with Spiramycin. Both of these antibiotics are bacteriostatic, and therefore may have a more limited effect than a bactericidal agent such as chlorhexidine. The Lactobacillus strains tested required higher concentrations of chlorhexidine than did the strains of Streptococcus for a killing effect in vitro.

Evaluation of gamma-glutamyl transpeptidase-to-creatinine ratio from spot samples of urine supernatant, as an indicator of urinary enzyme excretion in dogs.

gamma-Glutamyl transpeptidase activity was measured accurately in canine urine supernatant without gel filtration and was relatively stable at 4 C for at least 4 days after collection. The urinary gamma-glutamyl transpeptidase-to-creatinine ratio in spot samples was simple and quick to measure and was correlated with the 24-hour enzyme excretion. However, the usefulness of this ratio may be limited by within-day variation, and a questionable theoretical basis for its validity.

Correlation between anion gap, blood L lactate concentration and survival in horses.

Blood L lactate concentration and anion gap were measured in 32 horses suspected of having metabolic acidosis. There was good linear correlation between these variables (r = 0.90791, P less than 0.0001) and both were good prognostic indicators. Anion gap was a good indicator of the presence but not the severity of L lactic acidosis and was a slightly better prognostic indicator. The ability to predict survival was not improved by the measurement of L lactate in addition to anion gap.

Contribution of whole blood L-lactate, pyruvate, D-lactate, acetoacetate, and 3-hydroxybutyrate concentrations to the plasma anion gap in horses with intestinal disorders.

Increased anion gap (AG) was due, in part, to L-lactic acidosis in 14 of 14 horses with intestinal disorders. In a few horses, increased whole blood concentrations of D-lactate made a minor contribution to the AG. However, the increase in AG was often greater than the sum of the increases in these 2 acid anions. This unexplained increase was not a result of increases in whole blood pyruvate, 3-hydroxybutyrate, or acetoacetate concentrations or serum albumin or phosphate concentrations. Identification of other anions causing increased AG could lead to better understanding, diagnosis, and treatment of metabolic imbalances in critically ill horses.

Effects of heartworm and intestinal parasitic infections on hematology and peripheral lymph node cytology in louisiana dogs.

Hookworm infected dogs had higher blood basophil counts than hookworm negative dogs. Dogs with occult heartworm infection (i.e., without microfilaremia) had higher blood neutrophil counts than heartworm negative dogs. The percentage of eosinophils in peripheral lymph nodes was higher in heartworm infected, microfilaremic dogs than in both occult infected dogs and heartworm negative dogs. Heartworm or intestinal parasitic infection had no other significant effects on hematologic parameters or peripheral lymph node cytology.

Evaluating toxin-induced hepatic injury in rats by laboratory results and discriminant analysis.

The ability of 14 serum biochemical assays to predict the presence of hepatic necrosis induced by carbon tetrachloride (CCl4) (centrilobular necrosis), allyl alcohol (periportal necrosis), and 1-napththylisothiocyanate (ANIT) (biliary duct necrosis) was evaluated in rats. Results of these assays were analyzed using multivariate discriminant analysis to determine: which assays have the highest predictive value for discriminating between control and treated rats, and which assays would discriminate between rats in the three treatment groups. Individual assays with the highest predictive value for CCl4-induced lesions versus controls were glutamate dehydrogenase (GDH), sorbitol dehydrogenase (SDH), and alanine aminotransferase (ALT). Assays with the highest predictive value for ANIT-induced lesions were GDH, 5'-nucleotidase (5'NT), and ALT. Assays the highest predictive value for ANIT-induced lesions were GDH, 5'-nucleotidase (5'NT), and ALT. Assays with the highest predictive value for allyl alcohol-induced lesions were an ALT/isocitrate dehydrogenase (ICD) ratio, GDH, and ALT. Canonical correlation coefficients for each assay ranged from 0.98 to 0.91 with 95-100% correct group membership predictions (treated versus control) provided by each assay. Individual assays were not highly predictive for determining group membership among all three treatment groups. A two assay combination of 5'NT and an ALT/ICD ratio provided 100% correct group membership predictions and had high canonical correlations (f1 = 0.95, f2 = 0.83).

Sequential morphological and quantitative changes in blood and bone marrow neutrophils in dogs with acute inflammation.

Blood and bone marrow morphology were studied sequentially in dogs during experimental inflammation induced by intramuscular injection of turpentine. Depletion of the bone marrow storage pool of mature neutrophils and an increase in mitotic activity and number of early granulocyte precursors were evident within 24 hours. During the next three days, intense granulocytic hyperplasia resulted in replenishment of the bone marrow storage pool. Neutrophils with foamy vacuolation and increased basophilia of the cytoplasm (toxic neutrophils) were present in the blood by eight hours postinjection. The number of toxic neutrophils paralleled the intensity of clinical signs and changes in rectal temperature but not the number of band neutrophils. This indicates that changes in number of toxic neutrophils in sequential leukograms can be a prognostic indicator in dogs with severe inflammation.

In vitro function of canine neutrophils during experimental inflammatory disease.

The effect of acute inflammation on neutrophil function in the dog was studied by measuring in vitro phagocytosis and killing of Staphylococcus aureus. Phagocytosis was not impaired after 30 or 60 minutes and bactericidal activity was not impaired after 60 minutes incubation. However, average bactericidal activity after 30 minutes incubation was diminished significantly (P less than 0.01). Wide variations in bactericidal activity after 30 minutes incubation during the course of the inflammation did not correlate with neutrophil count, number of toxic neutrophils, or clinical course of the inflammation. These results indicate that a defect in bactericidal activity can occur in dogs with severe inflammatory disease, and that repeated assays, rather than single determinations, may be needed to detect this dysfunction.