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in category dentistry and oral medicine

148 results found. For more information, click each entry to expand.

1: Efficacy of commercial mouth-rinses on SARS-CoV-2 viral load in saliva: Randomized Control Trial in Singapore
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Posted 18 Sep 2020

Efficacy of commercial mouth-rinses on SARS-CoV-2 viral load in saliva: Randomized Control Trial in Singapore
5,657 downloads medRxiv dentistry and oral medicine

Chaminda Jayampath Seneviratne, Preethi Balan, Karrie Ko Kwan Ki, Nadeeka S. Udawatte, Deborah Lai, Dorothy Ng Hui Lin, Indumathi Venkatachalam, Jay Lim Kheng Sit, Ling Moi Lin, Lynette Oon, Bee Tin Goh, Jean Sim Xiang Ying

The presence of high SARS-coronavirus 2 (SARS-CoV-2) titres in saliva may result in transmission of the virus and increase the risk of COVID-19 infection. This is particularly important as significant amounts of aerosols are generated during dental procedures, posing risk to dental care personnel and patients. Thus, reducing the titres of SARS-CoV-2 in the saliva of infected patients could be one of the key approaches to reduce the risk of COVID-19 transmission during dental procedures. In this randomised control trial, the efficacy of three commercial mouth-rinse viz. povidone-iodine (PI), chlorhexidine gluconate (CHX) and cetylpyridinium chloride (CPC), in reducing the salivary SARS-CoV-2 viral load in COVID-19 positive patients were compared with water. A total of 36 COVID-19 positive patients were recruited, of which 16 patients were randomly assigned to four groups: PI group (n=4), CHX group (n=6), CPC group (n=4) and water as control group (n=2). Saliva samples were collected from all patients at baseline and at 5 min, 3 h and 6 h post-application of mouth-rinses/water. The samples were subjected to SARS-CoV-2 RT-PCR analysis. The fold change of Ct values were significantly increased in CPC group at 5 minutes and 6 h time points (p<0.05), while it showed significant increase at 6 h timepoint for PI group (p<0.01). Considering Ct values as an indirect method of arbitrarily quantifying the viral load, it can be postulated that CPC mouth-rinse can decrease the salivary SARS-CoV-2 levels within 5 minutes of use, compared to water rinsing. The effect of decreasing salivary load with CPC and PI mouth-rinsing was observed to be sustained at 6 h time point. Within the limitation of the current study, it can be concluded that use of CPC and PI formulated commercial mouth-rinses, with its sustained effect on reducing salivary SARS-CoV-2 level, may be useful as a pre-procedural rinse to help reduce the transmission of COVID-19.

2: Saliva as a Candidate for COVID-19 Diagnostic Testing: A Meta-Analysis
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Posted 27 May 2020

Saliva as a Candidate for COVID-19 Diagnostic Testing: A Meta-Analysis
4,077 downloads medRxiv dentistry and oral medicine

Laszlo Mark Czumbel, Szabolcs Kiss, Nelli Farkas, Ivan Mandel, Anita Emoke Hegyi, Akos Karoly Nagy, Zsolt Lohinai, Zsolt Szakacs, Peter Hegyi, Martin C. Steward, Gabor Varga

Objectives: Our aim was to conduct a meta-analysis on the reliability and consistency of SARS-CoV-2 viral RNA detection in saliva specimens. Methods: We reported our meta-analysis according to the Cochrane Handbook. We searched the Cochrane Library, Embase, Pubmed, Scopus, Web of Science and clinical trial registries for eligible studies published between 1 January and 25 April 2020. The number of positive tests and total number of conducted tests were collected as raw data. The proportion of positive tests in the pooled data were calculated by score confidence interval estimation with the Freeman-Tukey transformation. Heterogeneity was assessed using the I2 measure and the Chi2 test. Results: The systematic search revealed 96 records after removal of duplicates. 26 records were included for qualitative analysis and 5 records for quantitative synthesis. We found 91% (95%CI = 80%-99%) sensitivity for saliva tests and 98% (95%CI 89%-100%) sensitivity for nasopharyngeal swab (NPS) tests in previously confirmed COVID-19 infected patients, with moderate heterogeneity among studies. Additionally, we identified 18 registered, ongoing clinical trials on saliva-based tests for detection of the virus. Conclusion: Saliva tests offer a promising alternative to NPS for COVID-19 diagnosis. However, further diagnostic accuracy studies are needed to improve their specificity and sensitivity.

3: COVID-19 challenges to dentistry in the new pandemic epicenter: Brazil
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Posted 14 Jun 2020

COVID-19 challenges to dentistry in the new pandemic epicenter: Brazil
2,829 downloads medRxiv dentistry and oral medicine

Rafael R Moraes, Marcos Britto Correa, Ana B Queiroz, Ândrea Daneris, João P Lopes, Tatiana Pereira-Cenci, Otávio P D'Avila, Maximiliano Sergio Cenci, Giana S Lima, Flavio Fernando Demarco

A nationwide survey of dentists was carried out in Brazil, a new pandemic epicenter, to analyze how dental coverage has been affected (public versus private networks), changes in routine and burdens, and how the local prevalence of COVID-19 affects dental professionals. Dentists were recruited via email and an Instagram campaign. Responses to an online questionnaire were collected May 15-24, 2020. COVID-19 case/death counts in the state where respondents work was used to test associations between contextual status and decreases in weekly appointments, fear of contracting COVID-19 at work, and current work status (alpha=0.05). Over 10 days, 3,122 responses were received, with region, gender, and age distributions similar to those of dentists in Brazil. Work status was affected for 94% of dentists, with less developed regions being more impacted. The impact on routine was high or very high for 84%, leading to varied changes to clinic infrastructure, personal protective equipment use, patient screening, and increased costs. COVID-19 patients had been seen by 5.3% of respondents, and 90% reported fearing contracting COVID-19 at work. Multilevel statistics showed that greater case and death rates (1000 cases or 100 deaths per million inhabitants) in one's state increased the odds of being fearful of contracting the disease (by 18% and 25%). For each additional 1000 cases or 100 deaths, the odds of currently not working or treating emergencies increased by 36% and 58%. The reduction in patients seen weekly per dentist was greater in public (38.7+/-18.6) than in private clinics (22.5+/-17.8). This study provides early evidence of three major impacts of the pandemic on dentistry in Brazil: increasing inequalities due to coverage differences between public and private networks; adoption of new clinical routines, which are associated with an economic burden; and associations of regional COVID-19 incidence and mortality with fear of contracting the disease at work.

4: Ventilation rate assessment by carbon dioxide levels in dental treatment rooms
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Posted 08 Feb 2021

Ventilation rate assessment by carbon dioxide levels in dental treatment rooms
2,615 downloads medRxiv dentistry and oral medicine

Qirong Huang, Tamer Marzouk, Razvan Cirligeanu, Hans Malmstrom, Eli Eliav, Yanfang Ren

Objectives: The purpose of the present study was to monitor and evaluate CO2 levels in dental operatories using a consumer-grade CO2 sensor and determine the utility and accuracy of various methods using CO2 levels to assess ventilation rate in dental clinics. We aim to find a practical tool for dental practitioners to conveniently and accurately monitor CO2 levels and assess the ventilation rates in their office in order to devise a pragmatic and effective strategy for ventilation improvement in their work environment. Methods: Mechanical ventilation rate in air change per hour (ACHVENT) of 10 dental operatories was first measured with an air velocity sensor and air flow balancing hood. CO2 levels were measured in these rooms to analyze the effects of ventilation rate and number of persons in the room on CO2 accumulation. Ventilation rates were estimated using natural steady state CO2 levels during dental treatments and experimental CO2 concentration decays by dry ice or mixing baking soda and vinegar. We compared the differences and assessed the correlations between ACHVENT and ventilation rates estimated by steady states CO2 model with low (0.3 L/min, ACHSS30) or high (0.46 L/min, ACHSS46) CO2 generation rates, by CO2 decay constants using dry ice (ACHDI) or baking soda (ACHBV), and by time needed to remove 63% of excess CO2 generated by dry ice (ACHDI63%) or baking soda (ACHBV63%). Results: ACHVENT varied from 3.9 to 35.0 with a mean of 13.2 ({+/-}10.6) in the 10 dental operatories. CO2 accumulation occurred in rooms with low ventilation (ACHVENT [&le;]6) and more persons (n>3) but not in those with higher ventilation and less persons. ACHSS30 and ACHSS46 correlated well with ACHVENT (r=0.83, p=0.003), but ACHSS30 was more accurate for rooms with low ACHVENT. Ventilation rates could be reliably estimated using CO2 released from dry ice or baking soda. ACHVENT was highly correlated with ACHDI (r=0.99), ACHBV(r=0.98), ACHDI63%(r=0.98), and ACHBV63% (r=0.98). There were no statistically significant differences between ACHVENT and ACHDI63% or ACHBV63%. Conclusions: Dental operatories with low ventilation rates and overcrowding facilitate CO2 accumulations. Ventilation rates could be reliably calculated by observing the changes in CO2 levels after a simple mixing of household baking soda and vinegar in dental settings. Time needed to remove 63% of excess CO2 generated by baking soda could be used to accurately assess the ventilation rates using a consumer-grade CO2 sensor and a basic calculator.

5: Perceived Stress and Psychological (Dis)Stress among Indian Endodontists During COVID19 Pandemic Lock down
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Posted 10 May 2020

Perceived Stress and Psychological (Dis)Stress among Indian Endodontists During COVID19 Pandemic Lock down
2,096 downloads medRxiv dentistry and oral medicine

Anil Kumar Ramachandran Nair, Karumaran Savarimalai Chellaswamy, Deepthi Kattula, Rooban Thavarajah, Anusa Arunachalam Mohandoss

Background: The novel 2019 coronavirus(COVID-19) spreads by respiratory and aerosols. COVID19 driven pandemic causes panic, fear and stress among all strata of society. Like all other medical professions, dentists, particularly endodontists, who are highly exposed to aerosols would be exposed to stress. The aim of this study was to assess the (dis)stress among Indian endodontists and the factors that could influence the (dis)stress. Methods: From 8th April to 16th April 2020, we conducted an online survey in closed endodontic social media using snowball sampling technique, collecting basic demographic data, practice setting and relevant data. Psychological stress and perceived distress were collected through COVID-19 Peri-traumatic Distress Index (CPDI) and Perceived stress scale (PSS). Multinomial regression analysis was performed to estimate relative risk rate and P[&le;]0.05 was considered significant. Results: This study had 586 Indian endodontists completing this survey across India. Of these, 311(53.07%) were males, 325(55%) in the age group of 25-35 years, 64%in urban areas, 13.14% in solo-practice and a fourth of them were residents. Female endodontists had high perceived stress (RRR=2.46,P=0.01) as compared to males, as measured by PSS. Younger endodontists<25 years(RRR=9.75;P=0.002) and 25-35years (RRR=4.60;P=0.004) as compared with >45 years age-group had more distress. Exclusive consultants had RRR= 2.90, P=0.02, for mild-to-moderate distress as compared to normal. Factors driving this phenomenon are considered. Conclusions: During the lock down due to COVID-19, 1-in-2 Indian endodontists had distress, as measured by CPDI and 4-in-5 of them had perceived stress, as indicated by PSS. Our model identified certain factors driving the (dis)stress, which would help policy framers to initiate appropriate response.

6: A Systematic Review of Droplet and Aerosol Generation in Dentistry
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Posted 01 Sep 2020

A Systematic Review of Droplet and Aerosol Generation in Dentistry
2,038 downloads medRxiv dentistry and oral medicine

Nicola Innes, Ilona Johnson, Waraf Al-Yaseen, Rebecca Harris, Rhiannon Jones, Sukriti KC, Scott McGregor, Mark Robertson, William Wade, Jennifer Gallagher

Introduction: Against the COVID-19 pandemic backdrop and potential disease transmission risk by dental procedures that can generate aerosol and droplets. Objectives: This review aimed to identify which clinical dental procedures do generate droplets and aerosols with subsequent contamination, and for these, characterise their pattern, spread and settle. Materials and Method: Six databases were searched and citation chasing undertaken (to 11/08/20). Screening stages were undertaken in duplicate, independently, by two researchers. Data extraction was performed by one reviewer and verified by another. Results: Eighty-three studies met the inclusion criteria and covered: Ultrasonic scaling (USS, n=44), high speed air-rotor (HSAR, n=31); oral surgery (n=11), slow-speed handpiece (n=4); air-water (triple) syringe (n=4), air-polishing (n=4), prophylaxis (n=2) and hand-scaling (n=2). Although no studies investigated respiratory viruses, those on bacteria, blood splatter and aerosol showed activities using powered devices produced the greatest contamination. Contamination was found for all activities, and at the furthest points studied. The operator torso operator arm, and patient body were especially affected. Heterogeneity precluded significant inter-study comparisons but intra-study comparisons allowed construction of a proposed hierarchy of procedure contamination risk: higher risk (USS, HSAR, air-water syringe [air only or air/water together], air polishing, extractions using motorised hand-pieces); moderate (slow-speed handpieces, prophylaxis with pumice, extractions) and lower (air-water syringe [water only] and hand scaling. Conclusion: Significant gaps in the evidence, low sensitivity of measures and variable quality limit firm conclusions around contamination for different procedures. However, a hierarchy of contamination from procedures can be proposed for challenge/verification by future research which should consider standardised methodologies to facilitate research synthesis. Clinical significance (49 words): This manuscript addresses uncertainty around aerosol generating procedures (AGPs) in dentistry. Findings indicate a continuum of procedure-related aerosol generation rather than the current binary AGP or non-AGP perspective. This informs discussion around AGPs and direct future research to help support knowledge and decision making around COVID-19 and dental procedures.

7: Detection of cross-reactive IgA in saliva against SARS-CoV-2 Spike1 subunit
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Posted 01 Apr 2021

Detection of cross-reactive IgA in saliva against SARS-CoV-2 Spike1 subunit
1,992 downloads medRxiv dentistry and oral medicine

Keiichi Tsukinoki, Tatsuo Yamamoto, Keisuke Handa, Mariko Iwamiya, Juri Saruta, Satoshi Ino, Takashi Sakurai

Abundant secretory IgA (sIgA) in mucus, breast milk, and saliva provides immunity that prevents infection of mucosal surfaces. sIgA in pre-pandemic breast milk samples have been reported to cross-react with SARS-CoV-2, but whether it also occurs in saliva and, if so, whether it cross-reacts with SARS-CoV-2, has remained unknown. We aimed to clarify whether sIgA in saliva cross-reacts with SARS-CoV-2 spike 1 subunit in individuals who have not been infected with this virus. The study included 137 (male, n = 101; female, n = 36; mean age, 38.7 [24-65] years) of dentists and doctors in the Kanagawa Dental University Hospital. Saliva and blood samples were analyzed by PCR and immunochromatography for IgG and IgM, respectively. We then identified patients with saliva samples that were confirmed as PCR- and IgM-negative for COVID-19. Proportions of SARS-CoV-2 cross-reactive IgA-positive individuals were determined by enzyme-linked immunosorbent assay using a biotin-labeled spike S1-mFc recombinant protein covering the receptor-binding domain of SARS-CoV-2. The proportion of SARS-CoV-2 cross-reactive IgA-positive individuals was 46.7%, and this correlated negatively with age (r = -0.218, p = 0.01). The proportion of IgA-positive individuals [&le;] 50 y was significantly lower than that of patients aged [&ge;] 49 y (p = 0.008). sIgA was purified from the saliva of all patients, and the salivary sIgA was found to suppress the binding of SARS-CoV-2 spike protein to the ACE-2 receptor. We found SARS-CoV-2 cross-reactive sIgA in the saliva of some participants who had never been infected with the virus, suggesting that sIgA helps prevent SARS-CoV-2 infection.

8: Effectiveness of the Covid-19 vaccines in preventing infection in dental practitioners: results of a cross-sectional questionnaire based survey
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Posted 30 May 2021

Effectiveness of the Covid-19 vaccines in preventing infection in dental practitioners: results of a cross-sectional questionnaire based survey
1,841 downloads medRxiv dentistry and oral medicine

Sanjeev Kumar, Susmita Saxena, Mansi Atri, Sunil Kumar Chamola

India started its vaccination program at the beginning of 2021, the main beneficiaries being health workers and frontline workers including police, paramilitary forces, sanitation workers, and disaster management volunteers in the first phase. By the time, the second wave of Covid-19 impacted India, approximately 14 million healthcare and frontline workers, including dentists had been vaccinated. AimTo study the effectiveness of vaccination on a subset of high-risk healthcare workers i.e. dentists in preventing Covid-19 during the second wave of the pandemic. Study designA questionnaire based pan-India online survey was carried out to record the Covid-related experiences of dentists prior to and after vaccination. ResultDuring the second wave, 9.18% (n=364) respondents became positive in spite of the vaccine, while 14.69%(n=78) became positive in the unvaccinated group. A chi-square test of independence was performed to examine the relation between vaccination and the Covid positivity rate in all age groups. The relation between these variables was highly significant, [X2 (1, N = 4493) = 15.9809, p=.000064]. ConclusionOur pan-India online survey inferred that vaccination has a definitive role to play in reducing the positivity rate amongst dentists during the second wave of the pandemic across all age groups.

9: Prevalence and risk/protective indicators of peri-implant diseases: a university-representative cross-sectional study
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Posted 05 Jun 2020

Prevalence and risk/protective indicators of peri-implant diseases: a university-representative cross-sectional study
1,770 downloads medRxiv dentistry and oral medicine

Mario Romandini, Cristina Lima, Ignacio Pedrinaci, Ana Araoz, Maria Costanza Soldini, Mariano Sanz

Aim. To evaluate the prevalence of peri-implant diseases and to identify risk/protective indicators of peri-implantitis. Materials and Methods. 240 randomly selected patients from a university clinic database were invited to participate. Those who accepted, once data from their medical and dental history was collected, were examined clinically and radiographically to assess the prevalence of peri-implant health and diseases. A multilevel multivariate logistic regression analysis was carried out to identify those factors associated either positively (risk) or negatively (protective) with peri-implantitis defined as BoP/SoP and bone levels [&ge;]2 mm. Results. 99 patients with a total of 458 dental implants were analyzed. The prevalence of pre-periimplantitis and of peri-implantitis were respectively 56.6% and 31.3% at patient-level, while 27.9% and 31.7% at implant-level. The following factors were identified as risk indicators for peri-implantitis: smoking (OR=3.59; 95%CI:1.52-8.45), moderate/severe periodontitis (OR=2.77; 95%CI:1.20-6.36), <16 remaining teeth (OR=2.23; 95%CI:1.05-4.73), plaque (OR=3.49; 95%CI:1.13-10.75), implant malposition (too vestibular: OR=2.85; 95%CI:1.17-6.93), implant brand (Nobel vs. Straumann: OR=4.41;95% CI:1.76-11.09), restoration type (bridge: OR=2.47; 95%CI:1.19-5.12), and trauma as reason of tooth loss (OR=6.51;95% CI:1.45-29.26). Conversely, the following factors were identified as protective indicators: interproximal flossing/brushing (OR=0.27; 95%CI:0.11-0.68), proton pump inhibitors (OR=0.08; 95%CI:0.01-0.90) and anticoagulants (OR=0.08; 95%CI:0.01-0.56). Conclusions. Peri-implant diseases are highly prevalent among patients with dental implants in this university-based population. Several factors were identified as risk- and protective-indicators of peri-implantitis.

10: Fuzzy logic assisted COVID 19 safety assessment of dental care
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Posted 22 Jun 2020

Fuzzy logic assisted COVID 19 safety assessment of dental care
1,695 downloads medRxiv dentistry and oral medicine

Andrio Adwibowo

Uncertainty is significant when assessing a risk of certain health care facility conditions especially the facility that prone to the COVID 19 risk. One solution to deal with an uncertainty in health situation assessment is through fuzzy inference system. For that reason, this study aims to develop fuzzy assisted system to assess the safety of dental care related to the sets of patient and environmental conditions. The fuzzy system allows assessment based on the patient body temperature, travel history, dental care ventilation rate, and disinfection frequency. The fuzzy system incorporates several steps including fuzzification, fuzzy regulation, and defuzzification. As a result of this study, the fuzzy system is able to assess and identify the risk of dental care according to the patient health status and hygiene conditions of dental care as well. To conclude, fuzzy system used in this study has offered the advantage of assessing at any situation as for patient and environmental factor predicts the safety of dental care.

11: A clinical observational analysis of aerosol emissions from dental procedures.
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Posted 12 Jun 2021

A clinical observational analysis of aerosol emissions from dental procedures.
1,392 downloads medRxiv dentistry and oral medicine

Tom Dudding, Sadiyah Sheikh, Florence Gregson, Jennifer Haworth, Simon Haworth, Barry Main, Andrew Shrimpton, Fergus W Hamilton, AERATOR group, Tony Ireland, Nick Maskell, Jonathan P Reid, Bryan Bzdek, Mark Gormley

There remains uncertainty as to which dental procedures constitute aerosol generating procedures. We aimed to quantify aerosol concentration produced during different dental procedures. Where aerosol was detected, we assessed whether the aerosol size distribution from patient procedures was explained by the non-salivary contaminated instrument source, using phantom head controls. This study obtained ethical approval within the AERATOR grant. Patients were recruited consecutively, and written consent was obtained. Both an optical and an aerodynamic particle sizer were used to measure aerosol, attached to a 3D-printed polylactide funnel 22cm from the patients face. A range of periodontal, oral surgery and orthodontic procedures were captured using time-stamped protocols. High-fidelity phantom head control experiments for each procedure were performed, under the same conditions. Aerosol was measured for each procedure. Where aerosol was detected, phantom head control and patient procedure aerosol size distributions were compared, with the assumption that if the distributions were the same, aerosol detected from the patient could be explained by the instrument source. 41 patients underwent fifteen different dental procedures. For nine procedures, no aerosol was detected. Where aerosol was detected, the percentage of procedure time that aerosol was observed above background ranged from 12.7% for ultrasonic scaling to 42.9% for 3-in-1 air + water syringe. For ultrasonic scaling, 3-in-1 syringe use and surgical drilling, the aerosol size distribution matched the non-salivary contaminated instrument source. High and slow speed drilling produced aerosol from patient procedures which appear to have different size distributions from a phantom head control and so may pose a greater risk of (potentially infected) salivary contamination. Ultrasonic scaling does not appear to generate additional aerosol above that of the instrument itself and therefore does not increase the risk to dental teams, relative to the risk from being in close proximity to the patient.

12: Prevalence of Salivary IgA Reacting with SARS-CoV-2 among Japanese People Unexposed to the Virus
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Posted 10 Jan 2022

Prevalence of Salivary IgA Reacting with SARS-CoV-2 among Japanese People Unexposed to the Virus
1,357 downloads medRxiv dentistry and oral medicine

Keiichi Tsukinoki, Tetsuro Yamamoto, Jiro Saito, Wakako Sakaguchi, Keiichiro Iguchi, Yoshinori Inoue, Shigeru Ishii, Chikatoshi Sato, Mina Yokoyama, Yuki Shiraishi, Noriaki Kato, Hiroyasu Shimada, Akio Makabe, Akihiro Saito, Masanori Tanji, Isao Nagaoka, Juri Saruta, Tetsutaro Yamaguchi, Shigenari Kimoto, Hideyo Yamaguchi

While the COVID-19 pandemic caused by SARS-CoV-2 has posed a threat to public health as the number of cases and COVID-19-related deaths are increasing worldwide, the incidence of the virus infection are extremely low in Japan compared with many other countries. To explore the reason for this strange phenomenon, we hypothesized the high prevalence of "natural" secretory IgA in saliva as mucosal IgA reacting with SARS-CoV-2, and thus surveyed the positivity for, as well as levels of, such reactive salivary IgA in a cohort of Japanese people of a wide range of age. The major findings were that 95/180 (52.78 %) of overall individuals who had not been exposed to SARS-CoV-2 were positive for salivary IgA with the levels ranging from 0.002 to 3.272 ng/ml, and that there may be a negative trend in positivity for salivary IgA according to age. These results suggest a role of mucosal IgA in host defense against SARS-CoV-2 infection. One Sentence Summary"Natural" secretory immunoglobulin A autoantibodies may play a role in mucosal defense against SARS-CoV-2.

13: THE G-FORCE CONUNDRUM IN PRF GENERATION- MANAGEMENT OF A PROBLEM HIDDEN IN PLAIN SIGHT
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Posted 05 May 2020

THE G-FORCE CONUNDRUM IN PRF GENERATION- MANAGEMENT OF A PROBLEM HIDDEN IN PLAIN SIGHT
1,229 downloads medRxiv dentistry and oral medicine

Kidambi Sneha, Ajmera Jhansi Rani, Rampalli Viswa Chandra

Aim: A force of 400g at 2700 RPM results in an optimum leucocyte and platelet-rich fibrin (L-PRF). Most of centrifuges with varying characteristics generate a g-force in excess of 700g at 2700 RPM. In this context, the study explores the effect of the original centrifugation protocol and a modified protocol tailor-made to lower the RPM to generate a g-force of ~400g on platelet concentration, clot size and growth factors release in L-PRF prepared in two different commercially available centrifuges. Materials and Methods: 25 subjects each were assigned to the following groups; R1 and R2 where L-PRF was obtained from two laboratory swing-out centrifuges (Remi 8C(R) & C854(R), Mumbai, India) respectively. PRF was obtained from each subject within a group using two protocols; Original (O) protocol: conforming to the original centrifugation cycle (2700 RPM for 12 min) and Modified (M) protocol. Clot size, growth factor estimation and platelet counts were measured at 20, 40 and 60 mins from all the L-PRF clots. Results: At the third time period (40-60min), there were no significant differences in clot sizes with the original protocol (p=0.09), but a highly significant difference was noticed with the modified protocol in both the centrifuges (p=0.001). Our results showed an increased concentration of VEGF and EGF with modified protocol than with original protocol with both the centrifuges (p=0.001). By the end of second and third time periods, more platelet concentration was observed with modified protocol than with the original protocol in both the centrifuges (p=0.001) Conclusion: This study infers that the centrifuge type and RCF can affect the quality and quantity of cells and growth factors and an optimum relationship between g-force and RPM should be maintained in order to obtain L-PRF with adequate cell viability and optimum growth factor release.

14: Brazilian dental students and COVID-19: a survey on knowledge and perceptions
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Posted 30 Jul 2020

Brazilian dental students and COVID-19: a survey on knowledge and perceptions
1,204 downloads medRxiv dentistry and oral medicine

Maria Gerusa Brito Aragao, Francisco Isaac Fernandes Gomes, Leticia Pinho Maia Paixao de Melo, Silmara Aparecida Milori Corona

This study evaluated the knowledge and perception of Brazilian dental students about COVID-19 and the undergraduate clinical practice during the outbreak by a self-administered web-based questionnaire. A social network campaign on Instagram was raised to approach the reach population. The survey covered demographic and academic profile, general knowledge, preventive measures, and perception about the COVID-19. Descriptive statistics were used to identify frequencies and distributions of variables, which were compared by type of institution and current year of enrollment using Chi-square or Fishers exact tests (alpha=0.05). A total of 833 valid responses were received over 10 days. Students were able to identify the incubation period, main symptoms, and contagious routes of the disease but struggled in recognizing the name of the virus responsible for the pandemics. Hand washing before and after a dental appointment with a patient (97.7%) followed by use of barriers to protect mucosa (97.2%) were the more frequently recognized measures to prevent COVID-19 spread in the dental office. As for the perception of COVID-19, 73.2% of the dental students perceive the disease as severe, while only 11.1% of them think that COVID-19 is severe only for people presenting risk factors. Dental students knowledge and perception were associated with the type of institution and year of enrollment. In summary, the dental students demonstrated an acceptable general knowledge about COVID-19, but dental schools will need to address gaps in knowledge and control measures and perceptions to ensure a safer return to practical activities.

15: Deep learning for caries detection using optical coherence tomography
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Posted 07 May 2021

Deep learning for caries detection using optical coherence tomography
1,118 downloads medRxiv dentistry and oral medicine

Yu-Ping Huang, Shyh-Yuan Lee

Early detection of dental caries has been one of the most predominant topics studied over the last few decades. Conventional examination through visual-tactile inspection and radiography can be inaccurate and destructive to teeth structure. The development of Optical Coherence Tomography (OCT) has given dentistry an alternative diagnostic technique, which has been proven by numerous studies, that it has better sensitivity, specificity, and non-invasive characteristics. The growing popularity of Artificial Intelligence (AI) also contributes to a more efficient and effective way of image-based detection and decision-making. Previous studies, which have attempted to employ AI for caries assessment, did not incorporate high-quality data. Hence, they were unable to produce valid and reliable results. This study highlights the importance of high-quality data and aims to bypass this issue, by implementing an improved methodology to the automated detection and diagnosis of dental caries depending on AI. A two-phase study was carried out to explore different methods for caries detection. Initially OCT was verified, by surveying experienced clinicians, to be a better imaging technique compared to radiography. Then, our study showed that Convolutional Neural Networks (CNNs) in the scope of AI surpassed the accuracy of human clinicians. The data was preprocessed and labelled with the ground truth corresponding to Micro-CT with rigorous definition. Statistical analysis performed was mainly based on weighted Kappa coefficient. The results suggested that OCT ({kappa} = .699, SD = .090) showed a higher accuracy than radiography ({kappa} = .407, SD = .049) and CNNs ({kappa} = .860, SD = .049) were rated higher than clinicians ({kappa} = .679; SD = .113), both within a .05 significance. The best result was carried out by ResNet-152, concluding diagnostic accuracy to be 95.21% and sensitivity 98.85%. The improved methodology of this study hopes to pave the way for future studies in AI application in Dentistry.

16: Oral ulcers of COVID-19 patients: a scoping review protocol
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Posted 26 Jan 2021

Oral ulcers of COVID-19 patients: a scoping review protocol
981 downloads medRxiv dentistry and oral medicine

Abanoub Riad, Julien Issa, Veronika Chuchmova, Esraa Gomaa, Andrea Pokorna, Jitka Klugarova, Miloslav Klugar

Objective: This scoping review aims to systematically identify the types, characteristics, and possible pathophysiologic etiologies of the oral ulcers that emerge in COVID-19 patients. Introduction: The oral cavity is a vulnerable niche for the most diverse microbial ecosystem in the human body; therefore, it presents a wide array of mucocutaneous complications that could indicate various acute and chronic conditions. The COVID-19-related oral conditions, including oral ulcers, had been widely debated as direct manifestations or indirect complications of the SARS-CoV-2 infection. According to a preliminary search of PROSPERO, MEDLINE, the Cochrane Database of Systematic Reviews and the JBI Evidence Synthesis, there is no published nor registered scoping review concerned with the oral ulcers of COVID-19 patients. Inclusion criteria: The review will include studies included COVID-19 patients whose infection had been confirmed by RT-PCR testing regardless of infection severity and clinical course. Only the studies that reported COVID-19 patients with oral ulcers. Methods: A three-phase search strategy will be carried out: an initial limited search, a full electronic search, and hand search using the reference lists of all included records. The main bibliographic databases of published literature will include MEDLINE (PubMed), Cochrane COVID-19 Study Register, EMBASE via Ovid, and Scopus. All identified records will be managed using EndNote 9.2, and the titles and abstracts will be screened against the inclusion criteria before the full text of all potentially relevant studies will be examined. The data will be presented in tabular form, rating maps, and narrative summary.

17: Dental-Facial Midline: An Esthetic Based Classification
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Posted 26 Apr 2021

Dental-Facial Midline: An Esthetic Based Classification
980 downloads medRxiv dentistry and oral medicine

Nischal Niraula, Reecha Acharya, Manoj Humagain, Zohaib Khurshid, Necdet Adanir, Dinesh Rokaya

BackgroundThe facial midline and dental midline play an important role in facial esthetics, cosmetic dentistry, facial plastic surgery, and anthropologic studies. ObjectivesThis study studied the dento-facial midline in Nepalese subjects and to classify the midline. MethodsThe study was done in 150 Nepalese subjects, mostly consisting of University students (70 males and 80 females). After obtaining ethical approval, facial and dental midlines were analyzed using a scale. ResultsIt showed 24 (16%) study subjects showed the coincidence of the facial midline with the maxillary and mandibular dental midlines. It showed that only 26 (16 %) subjects showed the coincidence of facial midline with only maxillary dental midline and 17 (11 %) subjects showed the facial midline coincidence with only mandibular dental midline. The dental midline discrepancy was more prevalent in the maxillary arch and more prevalent on the right side. Midline discrepancy is seen more in males compared to females. The majority of the deviation showed 1 mm, followed by 2 mm, and 3 mm. ConclusionsThe coincidence of the facial midline with both the maxillary and mandibular dental midlines is uncommon. Midline discrepancy is seen more in males compared to females. The majority of the subjects show a mild discrepancy of 1 mm. The midline discrepancy was more seen on the right side and in the maxillary arch.

18: Mouth-rinses and SARS-CoV-2 viral load in saliva: A living systematic review
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Posted 26 Mar 2021

Mouth-rinses and SARS-CoV-2 viral load in saliva: A living systematic review
976 downloads medRxiv dentistry and oral medicine

Akram Hernández Vásquez, Antonio Barrenechea Pulache, Daniel Comande, Diego Azañedo

Objective. To conduct a living systematic review of the clinical evidence regarding the effect of different mouth''rinses on the viral load of SARS''CoV''2 in the saliva of infected patients. The viral load in aerosols, the duration of the reduction in viral load, viral clearance, SARS''CoV''2 cellular infectivity, and salivary cytokine profiles were also evaluated. Materials and methods. This study was reported using the PRISMA guidelines. An electronic search was conducted in seven databases and in preprint repositories. We included human clinical trials that evaluated the effect of mouth''rinses with antiseptic substances on the viral load of SARS''CoV''2 in the saliva of children or adults that tested positive for SARS''CoV''2 using reverse transcriptase polymerase chain reaction (RT''PCR). Risk of bias was assessed using the ROBINS-I tool. PROSPERO registration number CRD42021240561. Results. Four studies matching eligibility criteria were selected for evaluation (n=32 participants). Study participants underwent oral rinses with hydrogen peroxide (H2O2) at 1 %, povidone''iodine (PI) at 0.5% or 1%, chlorhexidine gluconate (CHX) at 0.2% or 0.12% or cetylpyridinium chloride (CPC) at 0.075%. Only one study included a control group with sterile water. Three of the studies identified a significant reduction in viral load up to 3, 4, and 6 hours after the use of mouthwashes with PI, CHX, and CPC or PI vs. sterile water, respectively, while one study did not identify a significant reduction in viral load after the use of H2O2 rinses. Conclusions. According to the present systematic review, the effect of the use of mouth-rinses on SARS''CoV''2 viral load in the saliva of COVID''19 patients remains uncertain. This is mainly due to the limited number of patients included and a high risk of bias present in the studies analyzed. Evidence from well''designed randomized clinical trials is required for further and more objective evaluation of this effect.

19: The first 6 weeks: setting up a UK urgent dental care centre during the COVID-19 pandemic.
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Posted 11 May 2020

The first 6 weeks: setting up a UK urgent dental care centre during the COVID-19 pandemic.
967 downloads medRxiv dentistry and oral medicine

Emily Carter, Charlotte C Currie, Abisola Asuni, Rachel Goldsmith, Grace Toon, Catherine Horridge, Sarah Simpson, Christopher Donnell, Mark Greenwood, Graham Walton, Ben Cole, Justin Durham, Richard Holliday

Introduction: The COVID-19 pandemic has posed many challenges, including provision of urgent dental care. This paper presents a prospective service evaluation during establishment of urgent dental care in the North-East of England over a six-week period. Aim: To monitor patient volumes, demographics and outcomes at the North-East urgent dental care service and confirm appropriate care pathways. Main Outcome Methods: Data were collected on key characteristics of patients accessing urgent care from 23rd March to 3rd May 2020. Analysis was with descriptive statistics. Results: There were 1746 patient triages, (1595 telephone and 151 face-to-face) resulting in 1322 clinical consultations. The most common diagnoses were: symptomatic irreversible pulpitis or apical periodontitis. 65% of clinical consultations resulted in extractions, 0.5% an aerosol generating procedure. Patients travelled 25km on average to access care, however this reduced as more urgent care centres were established. The majority of patients were asymptomatic of COVID-19 and to our knowledge no staff acquired infection due to occupational exposure. Conclusion: The urgent dental care centre effectively managed urgent and emergency dental care, with appropriate patient pathways established over the 6-week period. Dental preparedness for future pandemic crisis could be improved and informed by this data.

20: The ADEPT Study, A Comparative Study of Dentists Ability to Detect Enamel-only Proximal Caries in Bitewing Radiographs With and Without the use of AssistDent(R) Artificial Intelligence Software
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Posted 14 Oct 2020

The ADEPT Study, A Comparative Study of Dentists Ability to Detect Enamel-only Proximal Caries in Bitewing Radiographs With and Without the use of AssistDent(R) Artificial Intelligence Software
939 downloads medRxiv dentistry and oral medicine

Hugh Devlin, Tomos Williams, Jim Graham, Martin Ashley

IntroductionReversal of enamel-only proximal caries by non-invasive treatments is important in preventive dentistry. However, detecting such caries using bitewing radiography is difficult, and the subtle patterns are often missed by dental practitioners. AimsTo investigate whether the ability of dentists to detect enamel-only proximal caries is enhanced by the use of AssistDent(R) Artificial Intelligence (AI) software. Materials and MethodsIn the ADEPT (AssistDent Enamel-only Proximal caries assessmenT) study, twenty-three dentists were randomly divided into a control arm, without AI assistance, and an experimental arm in which AI assistance provided on-screen prompts indicating potential enamel-only proximal caries. All participants analysed a set of 24 bitewings in which an expert panel had previously identified 65 enamel-only carious lesions and 241 healthy proximal surfaces. ResultsThe control group found 44.3% of the caries, whereas the experimental group found 75.8%. The experimental group incorrectly identified caries in 14.6% of the healthy surfaces compared to 3.7% in the control group. The increase in sensitivity of 71% and decrease in specificity of 11% are statistically significant (p<0.01). ConclusionsAssistDent(R) Artificial Intelligence software significantly improves dentists ability to detect enamel-only proximal caries and could be considered as a tool to support preventive dentistry in general practice. Key PointsEnamel-only proximal caries are often missed by dentists when examining bitewing radiographs. The use of AssistDent(R) Artificial Intelligence software results in a 71% increase in ability to detect enamel-only proximal caries accompanied by a 11% decrease in specificity. Artificial Intelligence software could be considered as a tool to support preventive dentistry in general practice.

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