Showing papers in "Brazilian Oral Research in 2021"

Knowledge, stress levels, and clinical practice modifications of Turkish dentists due to COVID-19: a survey study

Abstract: Dentists are exposed to the highest risk of occupational respiratory and droplet infections by working face-to-face with patients. The aim of this study was to investigate the knowledge of symptoms and modes of transmission of COVID-19, stress levels and clinical practice modifications of Turkish dentists during the COVID-19 pandemic. An online survey (15 questions) was sent to Turkish dentists from May 5 to 12 May, 2020. The survey comprised questions about dentists' demographic characteristics, their knowledge about COVID-19, stress levels and the measures taken in dental clinics against COVID-19. This study included a total of 1,095 Turkish dentists. The data were expressed as frequency with percentage values for overall variables. Dentists were most familiar with high fever among the symptoms of COVID-19 (99.4%) and 99.2% of them reported that COVID-19 was transmitted with eye, mouth and nasal mucosa contact on surfaces contaminated with the droplets of infected persons. While the stress levels of females were higher than males, the stress levels of dentists with more than 20 years of professional experience were found to be lower. Regarding the precautions to be taken as a preventive measure when working again, 86.6% of the dentists took precautions by increasing daily patient care intervals and only 38.4% of the dentists wore an N95 mask. During this pandemic, knowing the conditions about when the treatments can be applied and the precautions to be taken will shed light on dentistry staff. Current recommendations of national authorities about the coronavirus should be followed.

The unplanned and unequal expansion of Dentistry courses in Brazil from 1856 to 2020.

Abstract: This study analyzed the consequences of the disordered expansion of Dentistry courses on the distribution of professionals, the job market, and limitations of the National System of Higher Education Assessment (SINAES) developed as a guarantee of education quality. This observational, descriptive, and analytical study used secondary data from several official databases. The number of courses was obtained from the e-MEC registry. From the Higher Education Census, the study collected historical series of courses offered, number of candidates per open seat, number of individuals who initiated and completed the course, and information about professors in the public and private schools. The reports related to Dentistry courses from the National Health Council were also analyzed. The performance of undergraduate students was assessed from synthesis reports of Enade from 2004 to 2016. The number of dentists and their regional distribution was based on the Federal Dental Council, and Brazilian population and gross domestic product were collected from the Brazilian Institute of Geography and Statistics. Dentistry courses in Brazil grew exponentially from 1856 to 2020; among the 544 authorized courses, 82 currently have not yet started their activities. The fast expansion of courses in Brazil has worsened the regional asymmetries in the supply of dentist, and the SINAES has not been able to fully assure the quality of Dentistry courses. Brazilian dentistry, which has increased its scientific and technological development since the 19th century, with outstanding intellectual production, is at risk of a collapse due to a plethora of dentists.

Cone-beam computed tomography cinematic rendering: clinical, teaching and research applications

Abstract: Cone-beam computed tomography (CBCT) is an essential imaging method that increases the accuracy of diagnoses, planning and follow-up of endodontic complex cases. Image postprocessing and subsequent visualization relies on software for three-dimensional navigation, and application of indexation tools to provide clinically useful information according to a set of volumetric data. Image postprocessing has a crucial impact on diagnostic quality and various techniques have been employed on computed tomography (CT) and magnetic resonance imaging (MRI) data sets. These include: multiplanar reformations (MPR), maximum intensity projection (MIP) and volume rendering (VR). A recent advance in 3D data visualization is the new cinematic rendering reconstruction method, a technique that generates photorealistic 3D images from conventional CT and MRI data. This review discusses the importance of CBCT cinematic rendering for clinical decision-making, teaching, and research in Endodontics, and a presents series of cases that illustrate the diagnostic value of 3D cinematic rendering in clinical care.

Influence of bone defect position and span in 3-point bending tests: experimental and finite element analysis.

Abstract: Three-point bending test is the most common mechanical test used for quantifying the biomechanical quality of bone tissue and bone healing in small animals. However, there is a lack of standardization for evaluation of bone repair by cortical perforation. The aim of this study was to determine the influence of bone defect position in the proximal metaphysis of rat tibias during load application and different span configuration on the three-point bending test outcomes. Cortical defects with 1.6 mm diameter were created at a standardized location on the medial surface of 60 tibias of male Wistar rats. The animals were euthanized 7 days after surgery. Five specimens were used to create 3D models for finite element analysis using high-resolution micro-CT images. Two spans (6 and 10mm) and three positions of the bone defect in relation to the load application (upward, frontal and downward) were evaluated experimentally (n = 10) and in finite element analysis (n = 5). Maximum load (N) and stiffness (N/mm) were statistically analyzed with 2-way ANOVA and Tukey test (α = 0.05). The results demonstrated that span and orientation of the bone defect significantly influenced the fracture pattern, stress distribution and force versus displacement relation. Therefore, reliable outcome can be achieved creating the bone defect at 8 mm from the extremity of the proximal epiphysis; placing a 10 mm distance span and downward facing defect position to allow a better distribution of stress and more fracture patterns that reached the bone defect target area with less intra-group variability.

LASER in periodontal treatment: is it an effective treatment or science fiction?

Abstract: There are several studies that evaluate the use of lasers in periodontal treatment in non-surgical or surgical therapy. However, while several studies showed clinically beneficial effects of some lasers in periodontal treatment, there are few clinical reports of additional advantages of lasers as adjunctive treatments in periodontology. The aim of this paper is to demonstrate and critically analyze the level of scientific evidence of effects of low-level lasers and high-power lasers in periodontology. A narrative review of the studies was carried out in each topic and type of laser or periodontal treatment. In nonsurgical periodontal therapy the results showed that there is an additional clinical benefit when using a diode laser (DL) associated with scaling and root planing (SRP) in patients with moderate to severe periodontitis. The Er:YAG laser seems to be the most suitable for nonsurgical periodontal therapy and promotes the same clinical effects as conventional therapy. In periodontal surgery vaporization of the gingival or mucosal tissue can be carried out with DL, CO2, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers. Photobiomodulation (PBM), mediated by low-level lasers associated with non-surgical periodontal therapy, promotes additional benefits in the short term and accelerates the bone and gingival tissue repair process and also reduces postoperative symptoms of periodontal surgery. The effect of antimicrobial Photodynamic Therapy is relevant in the initial reevaluation periods. Studies have shown controversial results of the use of lasers in periodontics, and this fact may be due to the lack of standard parameters of irradiation in each clinical application.

Effect of obturation technique using a new bioceramic sealer on the presence of voids in flattened root canals.

Abstract: The aim of this study was to evaluate the filling ability of a new ready-to-use calcium silicate-based sealer using thermoplastic or single-cone technique in flattened root canals. Twenty-four flattened distal canals of mandibular molars with a buccolingual diameter 4 or more times larger than the mesiodistal diameter were selected. The root canals were prepared and filled (n = 12), according to the following techniques: thermoplastic or single-cone technique using Bio-C Sealer. The teeth were scanned using Skycan 1176 micro-computed tomography (micro-CT) - voxel size 8.74 µm, before and after filling the root canal. The percentage of voids in the filled root canals was evaluated, and the data were statistically analyzed using the unpaired t-test (α = 0.05). The root canals filled using the thermoplastic technique created a smaller percentage of voids in the cervical/middle thirds than those filled using the single-cone technique (p 0.05). The flattened root canals in the cervical/middle thirds were better filled using the ready-to-use calcium silicate-based sealer associated to the thermoplastic technique, compared with the single-cone technique. In the apical third, the techniques showed similar filling ability.

New tendencies in non-surgical periodontal therapy.

Abstract: The aim of this review was to update the evidence of new approaches to non-surgical therapy (NSPT) in the treatment of periodontitis. Preclinical and clinical studies addressing the benefits of adjunctive antimicrobial photodynamic therapy, probiotics, prebiotics/synbiotics, statins, pro-resolving mediators, omega-6 and -3, ozone, and epigenetic therapy were scrutinized and discussed. Currently, the outcomes of these nine new approaches, when compared with subgingival debridement alone, did not demonstrate a significant added clinical benefit. However, some of these new alternative interventions may have the potential to improve the outcomes of NSPT alone. Future evidence based on randomized controlled clinical trials would help clinicians and patients in the selection of different adjunctive therapies.

Prosthodontic practice during the COVID-19 pandemic: prevention and implications

Abstract: The objective of this review is to identify preventive measures for COVID-19 to safeguard dental professionals providing prosthodontic dental care. Electronic searches were performed in PubMed, Scopus, and Cochrane databases using the following descriptors and/or words: "COVID-19," "SARS-CoV-2," "Dental practice," "Prosthodontics," and "Dental infection control." Prosthodontists are at high risk for exposure to the novel coronavirus through aerosols and possibly contaminated surfaces and indirect contact with dental laboratories and dental technicians through impressions, dental stone casts, and fixed and removable prosthetic appliances. Therefore, preventive measures should be implemented, including performing emergency treatments only, rescheduling patients with suspected disease, disinfecting surfaces and prosthodontic materials with biocidal substances, and using protective equipment such as N95 masks, disposable gowns, and face-shields.

Dental caries prevalence, prospects, and challenges for Latin America and Caribbean countries: a summary and final recommendations from a Regional Consensus.

Abstract: Dental caries can be effectively managed and prevented from developing into cavitated lesions while preserving tooth structure at all levels. However, the strong correlation between caries and socioeconomic factors may compromise the efficacy of preventive strategies. The high prevalence of persistent inequalities in dental caries in Latin American and Caribbean countries (LACC) is a matter of concern. The estimates of the burden of disease in some countries in this region are outdated or absent. This paper aims to summarize and present the final recommendations of a regional Consensus for Dental Caries Prevalence, Prospects, and Challenges for LACC. This consensus is based on four articles that were written by a team of Latin American experts, reviewed by dental associations, and presented and discussed in two consensus events. The following domains were explored: epidemiology, risk factors, prevention strategies, and management of dental caries with a focus on restorative procedures. Dental caries can manifest throughout the lifespan of an individual, making it a matter of concern for infants, children, adults, and older people alike. The prevalence rates of untreated caries in deciduous and permanent teeth are high in many parts of the world, including LACCs. Previous evidence suggests that the prevalence of dental caries in 12-year-olds is moderate to high in most Latin American countries. Moreover, the prevalence of treatment needs and dental caries in the adult and elderly population can also be regarded as high in this region. The risk/protective factors (e.g., sugar consumption, exposure to fluoride, and oral hygiene) probably operate similarly in all LACCs, although variations in the interplay of these factors in some countries and within the same country cannot be ruled out. Although salt and water fluoridation programs are implemented in many countries, there is a need for implementation of a surveillance policy. There is also room for improvement with regard to the introduction of minimal intervention techniques in practice and public health programs. Dental caries is a marker of social disadvantage, and oral health promotion programs and interventions aimed at reducing the burden of dental caries in LACCs must consider the complexity of the socioeconomic dynamics in this region. There is an urgent need to promote engagement of stakeholders, policymakers, medical personnel, universities, dental associations, community members, and industries to develop regional plans that enhance the oral health agenda for LACCs. A list of recommendations has been presented to underpin strategies aimed at reducing the prevalence and severity of dental caries and improving the quality of life of the impacted LACC population in the near future.

Management of dental caries lesions in Latin American and Caribbean countries.

Abstract: Caries management at the lesion level is dependent on the lesion activity, the presence of a cavitation (either cleanable or non-cleanable), and lesion depth as evaluated via radiographic examination. A variety of non-invasive, micro-invasive, and minimally invasive treatment (with or without restoration) options are available for primary and permanent teeth. Non-invasive strategies include oral hygiene instructions, dietary counseling, and personal as well as professional use of fluoridated products that reduce demineralization and increase re-mineralization. Micro-invasive procedures include the use of occlusal resin sealants and resin infiltrants, while minimally invasive strategies comprise those related to selective removal of caries tissues and placement of restorations. Deep caries management includes indirect pulp capping, while exposed pulp may be treated using direct pulp capping and partial or complete pulpotomy. The aim of the present study was to review available evidence on recommended preventive and restorative strategies for caries lesions in Latin American/Caribbean countries, and subsequently develop evidence-based recommendations for treatment options that take into consideration material availability, emphasize ways to adapt available treatments to the local context, and suggest ways in which dentists and health systems can adopt these treatments.

Does the premature loss of primary anterior teeth cause morphological, functional and psychosocial consequences?

Abstract: Premature loss of primary anterior teeth in deciduous arches is a controversial topic in the literature, especially due to the lack of robust scientific evidence regarding the types and magnitudes of the consequences involved. Morphological, functional, and psychosocial problems may arise from untreated premature loss of primary incisors and canines. The morphological problems include impaction and eruption disturbances of permanent successors; inclination and/or extrusion of adjacent and antagonist teeth, respectively; midline deviation; and crowding. Functional complications, such as speech disorders, aesthetic problems, and development of non-nutritive habits may occur, resulting in psychosocial implications, including a decrease in self-esteem, and even being targeted for bullying. The current critical review aimed to present and discuss the evidence available in the literature about the etiology, characteristics, implications and interventions resulting from the premature loss of primary anterior teeth. It is of utmost importance that future studies be developed to support the clinical decisions made by dental professionals on this topic.

The 100 most-cited papers in oral medicine and pathology

Abstract: This study aimed to analyze the 100 most-cited papers in the field of oral medicine and pathology over time, identifying the areas of more intense research. Papers in journals of oral medicine and pathology were identified using the Web of Science database. The specified research period was between 1900 and 2019. Descriptive statistics was used to analyze the data. Pearson’s correlation analysis was used to explore the relationships among Web of Science citations, Dimensions citations, and Altmetric Attention Score. The number of citations of an article in the top 100 most-cited papers published in 1953 or later ranged from 541 to 3623. The papers were published in 47 different journals. The New England Journal of Medicine, American Cancer Society, and Nature Genetics published the most papers. Authors from 18 different countries published papers on head and neck cancer, craniofacial congenital anomalies, and osteonecrosis. Most of the papers were laboratory and descriptive studies. A correlation analysis showed a strong correlation only between Web of Science and Dimensions citations. In sum, although non-specific journals for pathology and oral medicine published the majority of the 100 most-cited papers, this biometric citation study show that head and neck cancer was the issue with the most citations. Together, these results make an important scientific contribution by providing a historical perspective on the research carried out.

Community interventions and strategies for caries control in Latin American and Caribbean countries.

Abstract: Dental caries remains highly prevalent in Latin American and Caribbean countries (LACC). However, this disease can be controlled through interventions that implement evidence-based strategies in an affordable manner and that target all population groups instead of the most affluent only. Therefore, the aim of this report was to summarize the main scientifically documented community interventions and strategies based on restriction of sugars consumption, use of fluoride, and the use of occlusal sealants for caries control in LACC. A critical literature review was carried out in a systematic manner that included defined search strategies, independent review of the identified publications, and compilation of results in this report. Three systematic searches were conducted using the PubMed, LILACS, and SciELO databases to identify studies related to community interventions and strategies for caries control in LACC. Of the 37 publications identified, twenty-six focused on fluoride use, eight on occlusal sealant use, and three on the restriction of sugar consumption. Documented community interventions for sugars restriction were scarce in the region and were based on food supplementation, sugar replacement, and education. Thus, local and/or national policies should prioritize investment in upstream, coherent, and integrated population-wide policies such as taxes on sugary drinks and stronger regulation of advertising and promotion of sugary foods and drinks mainly targeting children. The main fluoride-based strategies used drinking water, refined domestic salt, cow milk, toothpaste and, to a lesser extent, mouth-rinses, acidulated phosphate fluoride (APF) gels, and varnishes to deliver fluoride to the population. Evidence of fluoride use was seen in Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Uruguay, and Venezuela. Studies reporting the use of occlusal sealants were mainly located in Brazil, Chile, Colombia, Costa Rica, Peru, Mexico, and Venezuela. Community interventions restricting sugar consumption should be implemented at the individual level and through public policies. The use of fluoride must be monitored at the local, regional, and national levels so as to achieve maximum anti-caries effect while also minimizing the risk of dental fluorosis. Moreover, fluoridated water and salt programs, used as a mutually exclusive community level strategy for caries control, should expand their benefits to reach non-covered areas of the LACC while also simultaneously providing adequate surveillance of the fluoride concentration delivered to the population. Regulating the concentration of soluble fluoride (for anti-caries effect) in dentifrice formulations is also necessary in order to provide the population with an effective strategy for disease control. Targeting culturally appropriate, economically sustainable caries control interventions to rural populations and native ethnic groups such as indigenous people, quilombolas (African-origin), and riverside Amazonian people remains a crucial challenge.

Characterization of low-cost Brazilian resin composites submitted to tooth brushing.

Abstract: This in vitro study aimed to evaluate surface microhardness, roughness, color, gloss and topography of low-cost Brazilian resin composites, compared with an international one. All 120 samples (8mm o x 2mm height) were prepared and divided into 5 groups: Ultrafill (Biodinâmica), Llis (FGM), Fill Magic (Coltene), Applic (Makira), and Filtek Z250XT (3M Oral Care). Surface microhardness (KHN) (n=10) was analyzed at two time periods: before and after simulated tooth brushing (STB). Other standardized samples of each group (n=10) were analyzed for surface roughness (Ra), color (ΔL, Δa, Δb, ΔE, ΔE00) and gloss unit (GU) at the same two periods. The topography of non-brushed and brushed samples of each group (n=4) was evaluated by scanning electron microscopy. Data were analyzed statistically by two-way repeated measures ANOVA with Bonferroni post-hoc test (KHN, Ra, GU), and one-way ANOVA with Tukey post-hoc test (ΔL, Δa, Δb, ΔE, ΔE00) (α=0.05). Topographic images were submitted to descriptive analysis. The low-cost Brazilian resin composites investigated were compared with the international one and revealed: lower KHN, regardless of before or after STB; statistically similar Ra before STB, except Ultrafill, which presented higher values; lower Ra after STB, except Ultrafill, which presented statistically similar values; statistically similar color change in ΔL, Δa, Δb parameters; statistically similar color change in ΔE, ΔE00 parameters, except Fill Magic, which presented lower values; lower gloss before STB; lower gloss after STB, except Ultrafill, which presented statistically similar values. In a situation of scarce resources, low-cost Brazilian composites might be an acceptable cost-effective restorative alternative.

COVID-19 Pandemic impact on Brazil's Public Dental System

Abstract: The present study aimed to estimate the impact of the COVID-19 pandemic on dental care procedures in the Public Health System in Brazil. A retrospective, ecological study was carried out, comprising 5,564 Brazilian municipalities. The number of dental procedures (per 100,000 inhabitants) performed in the Brazilian Public Health System (SUS) was the outcome. The impact of the pandemic was estimated by comparing the rate of procedures for each month of 2020 with the rates observed in the equivalent months in 2019, considering the period from March to August. Regulatory legislation regarding restrictions on dental care, issued by the state governments of 27 Brazilian federative units, was used for mediation analysis. A 55% reduction was observed in March for all procedures (IRR = 0.45, 95%CI 0.39-0.51), while in the other months, the rate of reduction remained ≥ 88%. The biggest decrease was observed in collective preventive procedures (reduction ≥99%) between April and August. Procedures that were less likely to generate aerosols (tooth extraction and prosthetic) and emergencies showed the smallest reduction. The reduction was not mediated by the restrictions imposed by state governments (p>0.05). The impact of the COVID-19 pandemic was noteworthy in terms of the decrease in the number of dental procedures carried out in the Brazilian Public Dental Service. The lack of access, the delay of elective procedures and the lack of preventive collective procedures could result in an overburdened system, post-Pandemic.

YouTube™ and oral lichen planus: an appraisal of the educational quality of information

Abstract: The objective of this study was to analyze the quality of videos on oral lichen planus (OLP) available in YouTube™. A cross-sectional analytical study was conducted by searching the video sharing platform YouTube™. Videos aimed at clarifying the etiological and clinical characteristics, diagnostic criteria, treatment, and prognosis of OLP were included. A total of 481 videos were retrieved and 37 were included in the study according to the selection criteria established. Most of the videos evaluated (86.5%; n = 32) were produced by independent users. The average reliability was 1.8 and quality assessment classified only three videos (8.1%) as having good/excellent quality. A significant correlation was observed between the length of the video analyzed and its quality and reliability (p < 0.05), as well as between the reliability and usefulness of the video (p = 0.03). YouTube™ has become a leading source of information for the general population. However, a significant number of these videos have a low quality. Students, professionals, and healthcare providers must be more actively involved in providing clear, accurate, and reliable evidence-based information in an accessible language in order to enable significant improvement in patient care delivery.

Risk factors for dental caries in Latin American and Caribbean countries.

Abstract: Identifying the risk factors for dental caries is vital in epidemiology and clinical practices for developing effective preventive strategies, both, at the individual and collective levels. Different causality/determination models have been proposed to understand the development process of dental caries. In the present review, we designed a model inspired by the world-known social determinants models proposed in the 90s and more recently in the 10s, wherein the contextual factors are placed more externally and encompass the individual factors. The contextual factors included those related to the cultural and societal values, as well as the social and health government policies. The individual factors were classified into the following categories: socioeconomic (social class, occupation, income, and education level), demographic characteristics (age, sex, and ethnicity), behavioral factors (non-use of fluoride dentifrice, sugar consumption, poor oral hygiene, and lack of preventive dental care), and biological factors (recent caries experience/active caries lesions, biofilm retentive factors, developmental defects of the enamel, disabilities, saliva amount and quality, cariogenic biofilm). Each of these variables was addressed, while focusing on the current evidence from studies conducted in Latin American and Caribbean countries (LACC). Based on the proposed model, educational aspects were addressed, and individual caries risk assessment and management decisions were proposed; further, implications for public health policies and clinical practice were described. The identification of modifiable risk factors for dental caries should be the basis for multi-strategy actions that consider the diversity of Latin American communities.

A qualitative study on experiences of persons with schizophrenia in oral-health-related quality of life.

Abstract: Our study aimed to explore the views and experiences in oral health and oral-health-related quality of life (OHRQoL) of persons with schizophrenia (PWS) in order to expand the understanding of the factors that either limit or facilitate their healthcare pathway, which can ultimately optimize their oral health and/or OHRQoL. A qualitative study was conducted in France in the Cote d'Or department (530 000 in habitants) centered on PWS's perceived meanings regarding oral health or OHRQoL, and semi-structured individual interviews were used. A conventional content analysis approach was chosen in order to highlight unrevealed themes. A sample of 20 PWS (12 males; 8 females) with a median age was 45.8 (± 9.5) were recruited to assess views and experiences regarding OHRQoL, which were focused on three dimensions: an individual dimension related to experience of "oral symptoms", a second dimension related to experience of "stress and its management", and a third related to "Autonomy dimension in oral health". We showed that PWS clearly expressed their mental representations of oral health and OHRQoL. This study supports that PWS were able to define their needs and had the ability to discuss their oral health and OHRQoL. These finding could be used to support specific interventions for this population to better manage the negative impact of antipsychotics and help them to consult dentists on a regular basis.

Rethinking the decision-making process to treat gingival recession associated with non-carious cervical lesions.

Abstract: The presence of a tooth-surface defect, such as a non-carious cervical lesion (NCCL), associated with sites of gingival recession (GR) defects creates a combined soft tissue/tooth defect (CD) that requires a different treatment plan. This study aimed to critically review the literature regarding the available treatment protocols for CDs and suggest a new decision-making process. NCCLs were classified as Class A-: the cementoenamel junction (CEJ) was visible and the root surface discrepancy was 0.5 mm (with a step); Class B-: unidentifiable CEJ without a step; Class B+: unidentifiable CEJ with a step. NCCLs affecting both root and crown surfaces (Class B) lead to CEJ destruction and consequently eliminate an important landmark used before and after root coverage procedures. The depth of the root surface discrepancy is vital owing to its possible impact on soft tissue adaptation after healing, which, in turn, may influence the treatment options, namely the use of graft and/or composites to compensate for the discrepancy. Clinically, a step with horizontal depth greater than 0.5 mm should be recognized as the minimum threshold value to define this condition. Extremely deep defects tend to assume a V-shaped topography. Therefore, extremely deep V-shaped defects were classified into subclasses A+V, a V-shaped defect, and B+V, a V-shaped defect with loss of CEJ, for management considerations. The treatment options, supported by the literature, and a decision-making process to deal with each condition are presented.

Demystifying artificial intelligence and deep learning in dentistry.

Abstract: Artificial intelligence (AI) is a general term used to describe the development of computer systems which can perform tasks that normally require human cognition. Machine learning (ML) is one subfield of AI, where computers learn rules from data, capturing its intrinsic statistical patterns and structures. Neural networks (NNs) have been increasingly employed for ML complex data. The application of multilayered NN is referred to as "deep learning", which has been recently investigated in dentistry. Convolutional neural networks (CNNs) are mainly used for processing large and complex imagery data, as they are able to extract image features like edges, corners, shapes, and macroscopic patterns using layers of filters. CNN algorithms allow to perform tasks like image classification, object detection and segmentation. The literature involving AI in dentistry has increased rapidly, so a methodological guidance for designing, conducting and reporting studies must be rigorously followed, including the improvement of datasets. The limited interaction between the dental field and the technical disciplines, however, remains a hurdle for applicable dental AI. Similarly, dental users must understand why and how AI applications work and decide to appraise their decisions critically. Generalizable and robust AI applications will eventually prove helpful for clinicians and patients alike.

Polymorphisms of matrix metalloproteinase-7 and -9 are associated with oral tongue squamous cell carcinoma.

Abstract: Matrix degradation is an important event in the progression, invasion and metastasis of malignant head and neck lesions. Imbalances, mutations and polymorphisms of MMPs and their inhibitors are observed in several cancer subtypes. The aim of this study was to evaluate the association of the MMP-7 gene promoter (181 A/G) and MMP-9 (-1562 C/T) polymorphisms in oral tongue squamous cell carcinoma (OTSCC). MMP-7 (rs11568818) and MMP-9 (rs3918242) single-nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis in 71 cases of OTSCC. Normal tissue specimens were obtained from 60 healthy volunteers to serve as the control. The MMP-7 G allele and MMP-9 T allele were more frequent in the OTSCC group than the control group, but only when these two SNPs were taken together was a significant association found with the nodal metastasis of OTSCC (p < 0.001). Based on our results, SNPs in the promoter region of MMP-7 and MMP-9 appear to be associated with greater risk of developing OTSCC, and with a higher propensity to form metastatic tumors. In this respect, molecular studies investigating polymorphisms may be useful in predicting tumor behavior.

Saliva as a tool for monitoring hemodialysis: a systematic review and meta-analysis.

Abstract: This study aimed to assess whether the reductions in serum urea and creatinine levels are different from the reductions in salivary urea and creatinine levels that occur after hemodialysis in chronic renal patients. The systematic review protocol was registered in the PROSPERO database. Eight databases were searched to identify pretest-posttest studies of chronic kidney disease patients undergoing hemodialysis, with no language or year restrictions. The JBI Critical Appraisal Tool was used to assess the risk of bias. Meta-analyses using random-effect models were conducted to compare salivary and serum correlations and to pooled mean and proportion differences from pre- to posthemodialysis urea and creatinine levels by subgroup analysis. The I2 test was used to assess heterogeneity, and a meta-regression was performed to statistically assess correlations and differences in the pooled effects pre- and postdialysis. The Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) was used to assess the certainty of evidence. The search resulted in 1404 records, and only six studies (n = 252 participants) fulfilled the eligibility criteria and were included. The studies were published between 2013 and 2018. All studies showed a significant reduction in both salivary and serum urea/creatinine levels. All eligible studies presented a low risk of bias. The meta-analysis shows a moderate to high correlation between salivary and blood levels of urea (r: 0.79; 95% CI: 0.56-1.00) and creatinine (r: 0.64; 95%CI: 0.16–1.00), with a very low level of certainty. The reductions in salivary urea and creatinine levels are similar to and correlated with the reductions in blood urea and creatine levels after hemodialysis among chronic kidney disease patients.

Safety protocols for dental care during the COVID-19 pandemic: the experience of a Brazilian hospital service

Abstract: The coronavirus disease (COVID-19) has been prioritized in relation to other illnesses considered critical, such as cancer, cardiovascular diseases/stroke, diabetes, and autoimmune diseases. The management of patients with these diseases involves dental care to reduce systemic complications caused by odontogenic infections, and/or to treat oral manifestations of systemic comorbidities. In this regard, the dental care of these individuals must be guaranteed during the pandemic. Although a high risk of exposure to and catching of COVID-19 is expected to befall dental professionals, biosafety guidelines reduce the likelihood of infection. Thus, the current scenario poses challenges, and offers decision-making approaches and tools that facilitate the management of individuals with oral manifestations of chronic and/or critical diseases, using hospital-based services. This article presents an overview for hospital service providers who are at the forefront of COVID-19 care, including a secure protocol, and clinical guidelines based on the experience of the Hospital das Clinicas in Belo Horizonte, a public referral service, supported by the Brazilian National Health System.

Incidence of condylar resorption after bimaxillary, Lefort I, and mandibular surgery: an overview.

Abstract: The aim of the present overview was to evaluate the outcomes of systematic reviews to determine the incidence of condylar resorption in patients submitted to orthognathic surgery and analyze whether the risk of developing this condition is related to a specific type of surgery. Searches were conducted in the PubMed/MEDLINE, Embase, and Cochrane electronic databases for systematic reviews with quantitative data on condylar resorption due to any type of orthognathic surgery for dentoskeletal deformities published up to May 25, 2019. The AMSTAR 2 and Glenny tools were applied for the quality appraisal. Five systematic reviews were included for analysis. Only one article was considered to have high quality. Among a total of 5128 patients, 12.32% developed condylar resorption. From those patients, 70.1% had double jaw surgery, 23.4% had mandibular surgery alone, and in 6.5% a Lefort I technique was used. Based on these findings, bimaxillary surgery could be considered a risk factor for condylar resorption. However, these results should be interpreted with caution, since other factors, such as pre-operative skeletal deformities, type of movement, and type of fixation, can contribute to the development of this condition. Further studies should consider reporting main cephalometric data, temporomandibular diagnosis, hormonal levels, and tomographic measures before and after the surgery at least every 6 months during the firsts two years to identify accurately risk factors for condylar resorption.

Effect of S. mutans combinations with bifidobacteria/lactobacilli on biofilm and enamel demineralization.

Abstract: The present study evaluated the ability of Bifidobacterium and Lactobacillus species associated with streptococci to increase insoluble extracellular polysaccharide (EPS) production and initial caries lesion progression. Bovine enamel blocks (n = 190; 4 mm x 4 mm) were prepared, selected according to initial surface hardness (SH), and divided into two groups: a) double combinations: S. mutans with Bifidobacterium or Lactobacillus, and b) triple combinations: S. mutans and S. sobrinus with Bifidobacterium or Lactobacillus species. The blocks were exposed to the bacterial associations for 7 days. Subsequently, quantity of EPS from biofilms and caries lesion depth were determined by means of colorimetric and cross-sectional enamel hardness (ΔKHN) analysis. The data were submitted to one-way analysis of variance, followed by the Bonferroni test (p < 0.05). S. mutans with B. animalis or B. dentium produced a higher quantity of EPS; S. mutans + B. animalis led to the highest ∆KHN. S. mutans + S. sobrinus + B. longum induced greater EPS and ∆KHN values. In conclusion, associations of B. animalis and B. longum with streptococci promoted EPS production and caries lesion progression.

Streamlining the dental care during COVID-19 pandemic: updated clinical recommendations and infection control management framework

Abstract: Several guidelines for dental practice have been published by dental associations and regulatory boards since the beginning of the pandemic. Initially, all non-emergency dental treatment were suspended. Healthcare personnel around the world are gradually expanding back to elective procedures. International updated recommendations alert that professionals must maintain regular observation of local health department reports, ensure personal protective equipment, and screen all patients for COVID-19 signs and symptoms. Telehealth strategies, patient screening, rescheduling when presenting COVID-19 symptoms and/or history of contact with infected people and hand/environment hygiene practices are reinforced. Appropriate cleaning and surface disinfection are mandatory. The dental staff must be trained to use appropriate Personal Protective Equipment (PPE), following a risk assessment and standard precautions: gloves; fluid resistant disposable gown, eye protection (face shield or goggles) and a medical mask. A fit tested N95 or KN95 respirator (or higher) is recommended when aerosol generating procedures are performed. Only essential accompanying persons should attend to dental appointment with the patient and must wear a cloth face covering or facemask. Social distancing and mask wearing by all staff are necessary in all areas of the office. Dental health care providers should keep up to date to the current guidance of clinical practice during the pandemic.

Dental caries experience and its impact on quality of life in Latin American and Caribbean countries.

Abstract: Robust epidemiological data allow for logical interventions taken in the interest of public health Dental caries is a major public health problem driven by increased sugar consumption and various biological, behavioral, and psychosocial factors, and is known to strongly affect an individual's quality of life This study aims to critically review epidemiological data on the prevalence of dental caries in Latin American and Caribbean countries (LACC) and its impact on the oral health-related quality of life (OHRQoL) of the population Although the majority of national surveys did not include all age groups and several countries reported a reduction in the prevalence of cavitated carious lesions, most nations still exhibited a high burden of decayed teeth OHRQoL evaluation was limited to children and older adults only, and was not included in any national survey Study heterogeneity and methodological issues hindered comparison of evidence between studies and over time, and updating national level data on caries prevalence and its impact on OHRQoL should be prioritized in LACCs

The evaluation of psychological state of dental students during the COVID-19 pandemic

Abstract: The purpose of the present study was to assess anxiety among a sample of dentistry students during the COVID-19 pandemic. A total of 355 dentistry students (165 males and 190 females) completed the Health Anxiety Inventory (HAI), Beck Anxiety Inventory (BAI), State-Trait Anxiety Inventory-I (STAI-I), and State-Trait Anxiety Inventory II (STAI-II) questionnaires. and evaluations of HAI, BAI, STAI-I, and STAI-II were based on sex, dental school year, smoking habit, and lifestyle. Female students had higher HAI and BAI scores than male students (p = 0.009 and p = 0.001, respectively). Statistically significant differences in HAI scores existed between preclinical and clinical students (p = 0.048). The only statistical significant differences detected in STAI-I scores involved students with an extended family when compared to students without an extended family (p = 0.039). The HAI scores of students who had close contact were significantly higher than students who had no contact (p = 0.047). There were significant correlations between the four scales (p < 0.05). During the COVID-19 pandemic [was under control in Turkey?], the HAI scores were higher in female, clinical students and students who lived with an extended family.

Effects of clinical use of NiTi reciprocating instruments on cyclic and torsional resistance, and on roughness.

Abstract: The aim of the present study was to evaluate the cyclic fatigue, torsional resistance and surface roughness of Reciproc R25 instruments in four different situations, namely as new instruments and as instruments tested after clinical preparation of one, two or three maxillary molars with four root canals. The total time required to perform each root canal preparation was recorded. Cyclic fatigue resistance was determined by the time to fracture using a customized testing device (n = 10 per group). The torsional test evaluated the torque and angle of rotation to failure according to ISO 3630-1 (n = 10 per group). The roughness of the working parts of new and used instruments was evaluated with a profilometer (n = 5 per group). Statistical analysis was performed using one-way ANOVA and Tukey's test. The level of significance was set at 5%. No fractures or deformations were observed after clinical use. Higher preparation time was needed during the third use of the instruments for all root canals (p 0.05). Regarding the roughness measurements, groove depth was higher on new and one- versus two- or three-maxillary-molar-prepared instruments (p < 0.05). It can be concluded that the clinical use of Reciproc instruments increased preparation time and decreased surface roughness. However, clinical use did not affect the cyclic fatigue or torsional resistance of the Reciproc instruments.

Caries risk assessment in dental practices by dentists from a Brazilian community.

Abstract: Data on dental practices related to caries risk assessment (CRA) are scarce among Brazilian dentists. This study aimed to determine the prevalence of CRA use by dentists and factors associated with its use, as well as to quantify dentists' ratings of the importance of specific factors when treatment planning. Dentists registered at the Regional Council of Dentistry of Sao Paulo State - Araraquara region were sent two paper questionnaires that comprised: a) characteristics of dentists themselves, their practices, and their patients; and b) the translated version of the "Assessment of Caries Diagnosis and Caries Treatment" Questionnaire from the U.S. National Dental Practice-Based Research Network. Participants were 206 dentists who currently practiced in Araraquara and treated dental caries. Descriptive statistics and multiple logistic regression analyses were used for data analysis. Thirty-six percent of the dentists reported they perform CRA and, among them, 36% indicated they record the assessment on a special form that is kept in the patient chart. More years since dental school graduation (OR = 1.1, p = 0.002) and holding an advanced academic degree (OR=2.6, p=0.005) were associated with a higher likelihood of performing CRA, whereas exclusively using a private practice model (OR = 0.5, p = 0.016) was associated with a lower likelihood of performing CRA. The current oral hygiene and commitment to return for follow-up were the most important risk factors for treatment planning. In conclusion, CRA was not a routine procedure in daily practice among the majority of participating dentists. Specific demographic, practice and academic education characteristics were associated with performing CRA.