Characteristics of Root Canal Filling Materials for Primary Teeth: A Review of Literature

Objectives Different root canal filling materials show different clinical and radiographic success rates. Since there is controversy on the best root canal filling material in primary dentition, the aim of this study was to summarize information about root canal filling materials for primary teeth in terms of biocompatibility, cytotoxicity, resorption rate, and survival rate. Methods By searching online databases, studies that addressed biocompatibility, cytotoxicity, resorption, and survival rates of different root filling materials in primary teeth from 1985 to 2020 were evaluated and the required data were extracted. The results were tabulated and compared. Results Due to methodological discrepancies, different studies show different and sometimes inconsistent results, which make it hard to reach a final conclusion; but it seems that Vitapex and Maisto's paste are more biocompatible and have a good survival rate. Zinc oxide eugenol (ZOE) and calcium hydroxide have lower cytotoxicity among different filling materials. However, due to low resorption rate, ZOE can affect permanent successors. Conclusion Based on the unique characteristics of each patient, different filling materials may be used for a clinically optimal dental treatment.&nbsp

Removable Appliance For Oral Self-Mutilation In Lesch-Nyhan Syndrome. A Case Report

Objectives Lesch-Nyhan syndrome is a rare inherited disorder associated with self-harming behaviors, delayed mental and motor development, and disturbances such as dysarthria, choreoathetosis, and spasticity. Severe inflicted behaviors in Lesch-Nyhan syndrome often include chewing and biting of the lips or fingers, which often require management. Techniques to deal with these behaviors include using appliances that restrict the behavior or ultimately extracting the teeth. Case This case report presents a 6-year-old child with Lesch-Nyhan syndrome and self-mutilation. He had chronic wounds in his buccal mucosa due to severe biting. Two acrylic devices with anterior and posterior bite plates were designed for the maxillary and mandibular teeth. At the follow-up visits, the wounds had been healed, but due to shedding of the primary teeth, and poor patient cooperation, the appliance design was slightly changed. The design of the device used for the patient inspires similar devices for patients with self-mutilation behaviors. Conclusion Early diagnosis and management of patients suffering from self-injurious behaviors may improve oral health-related quality of life of these patients. Acrylic appliances seem to be effective to minimize injury and to enhance fast healing of oral lesions

Pediatric Dentistry at the Time of COVID-19 Pandemic: A Review of Literature and Guidelines

Objectives The aim of the present study was to review practical considerations, special precautions, and novel challenges of pediatric dentistry at the time of coronavirus disease 2019 (COVID-19) pandemic. Methods PubMed (Medline), Scopus, and Google Scholar were searched for related articles. The websites of organizations related to public health and dentistry were also electronically searched. All searches were performed before November 2020. Results In this paper, the findings were categorized as: (I) how to triage patients, (II) waiting room modifications, (III) how to use personal protective equipment, (IV) mouthwashes, (V) how to minimize aerosol production, (VI) how to manage routine dental treatments, (VII) pharmacological management, (VIII) how to manage pharmacological sedation and general anesthesia, and (IX) coincidence of COVID-19 and seasonal influenza. Some lifestyle changes during the pandemic which are important to know for pediatric dentists were also discussed. Conclusion The emergence of COVID-19 has brought novel challenges for dental professionals. Pediatric dentistry is even more important because children can be asymptomatic carriers of the virus since they usually present mild or no symptoms. In addition to the standard precautions, pediatric dentists should implement special precautions to prevent disease transmission

Endodontic Treatment of a Tooth with Traumatic Fracture of Root Middle Third

Root fracture occurs in 0.5 to 7% of all dental injuries. Subsequent to this injury, the coronal segment is displaced, while the apical segment is rarely displaced. Emergency treatment involves repositioning of the coronal segment close to the radicular segment as much as possible to enhance the chance of pulp revascularization. If pulp necrosis occurs, the infective products cause an inflammatory response and radiolucency is seen at the fracture line. In the present case, the patient had two maxillary central incisors with horizontal middle third root fractures due to a traumatic accident four years earlier. The right central incisor showed an endodontic abscess due to pulp infection in the coronal segment. The coronal fragment was treated. In this case study all signs and symptoms resolved after treatment and three year follow-up showed a successful treatment outcome. The left central incisor had a vital pulp according to vitality tests, so “observation only” strategy was considered for this tooth.Keywords: Dental Pulp; Endodontic; Mineral Trioxide Aggregate; Tooth Fracture; Traum

Survey of Anatomy and Root Canal Morphology of Maxillary First Molars Regarding Age and Gender in an Iranian Population Using Cone-Beam Computed Tomography

Introduction: The purpose of this study was to investigate the root and canal morphology of maxillary first molars with regards to patients’ age and gender with cone-beam computed tomography (CBCT). Methods and Materials: A total of 149 CBCT scans from 92 (67.1%) female and 57 (31.3%) male patients with mean age of 40.5 years were evaluated. Tooth length, presence of root fusion, number of the roots and canals, canal types based on Vertucci’s classification, deviation of root and apical foramen in coronal and sagittal planes and the correlation of all items with gender and age were recorded. The Mann Whitney U, Kruskal Wallis and Fisher’s exact tests were used to analyze these items. Results: The rate of root fusion was 1.3%. Multiple canals were present in the following frequencies: four canals 78.5%, five canals 11.4% and three canals 10.1%. Additional canal was detected in 86.6% of mesiobuccal roots in which Vertucci’s type VI configuration was the most prevalent followed by type II and I. Type I was the most common one in distobuccal and palatal roots. There was no statistically significant difference in the canal configurations in relation to gender and age as well as the incidence root or canal numbers (P>0.05). The mean tooth length was 19.3 and 20.3 mm in female and male patients, respectively which was statistically significant (P<0.05). Evaluation of root deviation showed that most commonly, a general pattern of straight-distal in the mesiobuccal and straight-straight for distobuccal and palatal roots occurred. In mesiobuccal roots, straight and distal deviations were more dominant in male and female, respectively (P<0.05). The prevalence of apical foramen deviation in mesiobuccal and palatal roots statistically differed with gender. Conclusion: The root and canal configuration of Iranian population showed different features from those of other populations.Keywords: Age; Cone-Beam Computed Tomography; Gender; Maxillary Molar; Root Canal Morphology; Tooth Anatomy

Spontaneously Healed Horizontal Root Fracture: A Case Report

Objectives: Root fracture occurs less frequently in comparison with other traumatic dental injuries, and accounts for about 0.5%-7% of all dental injuries in permanent dentition. Complications associated with root fracture include pulp necrosis, root resorption, and pulp canal obliteration. Maintaining tooth vitality is the mainstay of treatment of horizontal root fracture in permanent teeth. Case Presentation: In this study, a clinical case of horizontal root fractures in the middle third of maxillary right and left central incisors (teeth #11 and #21) of an 8-year-old girl is reported. The patient was followed-up for 3 years. The treatment plan was watchful waiting and after 3 years, the vitality tests were still positive, and no pathology was detected on control radiographs. Conclusion: Careful clinical examination, accurate diagnosis, and regular radiographic follow-ups are necessary for efficient treatment and successful outcome of teeth with horizontal root fractures

Applying GMDH artificial neural network to predict dynamic viscosity of an antimicrobial nanofluid

Objective (s): Artificial Neural Networks (ANN) are widely used for predicting systems’ behavior. GMDH is a type of ANNs which has remarkable ability in pattern recognition. The aim the current study is proposing a model to predict dynamic viscosity of silver/water nanofluid which can be used as antimicrobial fluid in several medical purposes.Materials and Methods: In order to have precise model, it is necessary to consider all influential factors. Temperature, concentration and size of nano particles are used as input variables of the model. In addition, GMDH artificial neural network is applied to design a proper model. Data for modeling are extracted from conducted experimental studies published in valuable journals. Results: The dynamic viscosity of Ag/water nanofluid is precisely modeled by using GMDH. The obtained values for R-squared is equal to 0.9996 which indicates perfect precision of the proposed model. In addition, the highest relative deviation for the model is 2.2%. Based on the values of these statistical criteria, the model is acceptable and very accurate. Conclusion: GMDH artificial neural network is reliable approach to predict dynamic viscosity of Ag/water nanofluid by using temperature, concentration and size of particles as input data

A review on the applications of nanotechnology in orthodontics

Objective (s): Nanotechnology has gained importance in recent years due to its ability in the enhancement of materials properties and other specifications such as antimicrobial properties. Nano-sized materials have been applied in various fields of dentistry. Nanotechnology can be employed in orthodontics to enhance the quality of treatment. In the current study, a comprehensive review is carried out on the applications of nanotechnology in orthodontics. Materials and Methods: In the first step, various databases such as Scopus, Google Scholar and Pubmed were searched by using appropriate keywords for the present study. Afterwards, the related resources were selected to be reviewed. Finally, the key findings of the reviewed studies were represented and summarized. Results: Based on the reviewed researches, nanotechnology is applicable in various aspects of orthodontics. By using nanotechnology, improved properties in mechanical and medical specifications are achievable. For instance, by using nano coating in archwires, the friction force between components can be reduced and facilitate its motion. In addition, adding some types of nano particles to the composites resulted in improvement in tensile and shear bond strength. Antimicrobial properties of specific nano particles such as silver makes them favorable for reducing microorganisms in orthodontics treatment. Moreover, nanotechnology can be used in nano-identation test to assess the tools employed in orthodontics. Conclusion: nanotechnology can be broadly employed in orthodontics to achieve better treatment including improved strength of utilized materials, more accurate positioning and reduced microorganisms

Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c

Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks