Mandibular second premolars with three root canals: A review and 3 case reports

ABSTRACT: Before initiating any endodontic therapy, probability of extra canals should be considered. The Incidence of three canals in mandibular second premolar has been reported to be 0.46-0.5%. The present report describes nonsurgical endodontic treatment of three mandibular second premolars with three canals. In these cases, three orifices were located in mesiobuccal, distobuccal and lingual. Mesiobuccal orifices were found after removing dentinal shelves. Even in teeth with extremely complex root canal morphologies, conventional endodontic treatment without surgical intervention can result in adequate healing, as in these cases. Clinicians should be aware of unusual root canal anatomy in mandibular premolars. Very careful examination of the pulpal space, preferably with an optical device is recommended to locate any unusual orifices

In Vitro Sealing Properties of Calcium-Enriched Mixture and Mineral Trioxide Aggregate Orifice Barriers during Intra-Coronal Bleaching

Introduction: This study aimed at evaluating the sealing properties of calcium-enriched mixture (CEM) compared to mineral trioxide aggregate (MTA) as a cervical barriers in intra-coronal bleaching. Methods and Materials: In this in vitro study, endodontic treatment was performed on 60 extracted human incisors and canines without canal calcification, caries, restorations, resorption or cracks. The teeth were then randomly divided into two experimental groups and two control groups (n=15). Then, CEM cement and MTA were applied as 3-mm intra-orifice barriers in the test groups; a mixture of sodium perborate and 30% hydrogen peroxide bleaching agents were placed within the pulp chamber for one week. Dye penetration method was used to evaluate the sealing ability of agents. Statistical analysis was performed using SPSS software. The Kendall coefficient was used to evaluate inter-observer agreement. The chi-squared test was used for statistical analysis. Results: The results showed that the penetration rates of CEM and MTA were the same as positive control group, with no significant differences (P=0.673 and P=0.408, respectively). However, there was a significant difference between the negative control group and CEM and MTA groups (P=0.001 for both groups). In addition, the sealing ability of MTA and CEM cement were not significantly different (P=0.682). Conclusion: During intra-coronal bleaching procedures CEM cement can be used as a cervical barrier with sealing properties comparable to that of MTA.Keywords: Calcium-Enriched Mixture Cement; Cervical Barrier; Intra-Coronal Bleaching; Mineral Trioxide Aggregat

Radiographic Evaluation of Root Canal Fillings Accomplished by Undergraduate Dental Students

Introduction: The purpose of this study was to evaluate the radiographic quality of root canal fillings by fourth-, fifth-, and sixth-year undergraduate students at Tabriz Faculty of Dentistry between 2006 and 2012. Methods and Materials: A total of 1183 root canal fillings in 620 teeth were evaluated by two investigators (and in case of disagreement by a third investigator) regarding the presence or absence of under-fillings, over-fillings and perforations. For each tooth, preoperative, working and postoperative radiographs were checked. The Pearson’s chi-square test was used for statistical evaluation of the data. Inter-examiner agreement was measured by Cohen’s kappa (k) values. The level of significance was set at 0.05. Results: Total frequencies of over-filling, under-filling and perforation were 5.6%, 20.4% and 1.9%, respectively. There were significant differences between frequencies of over- and under-fillings (P<0.05). Unacceptable quality, under- and over-fillings were detected in 27.9% of 1183 evaluated canals. Conclusion: The technical quality of root canal therapies performed by undergraduate dental students using step-back preparation and lateral compaction techniques was unacceptable in almost one-fourth of the cases

Physicians’ and nurses’ decision making to encounter neonates with poor prognosis in the neonatal intensive care unit

This is an Accepted Manuscript of an article published by Sage in Clinical Ethics on 03/06/2020. Available online: https://journals.sagepub.com/doi/abs/10.1177/1477750920927173This is an Accepted Manuscript of an article published by Sage in Clinical Ethics on 03/06/2020.Available online: https://journals.sagepub.com/doi/abs/10.1177/1477750920927173acceptedVersio

Comparing the size and weight of placenta and birth weight in normal pregnancy and gestational diabetes: brief report

Background: Diabetes can cause undesirable changes in structure of the placenta, re-sulting increase in size and weight of placenta. The aim of this study was, to investigate the placenta weight, size and birth weight of infants in pregnant women with controlled gestational diabetes compared with normal pregnancy. Methods: This study was conducted from October, 2012 to February, 2014 in two dif-ferent hospitals, Valiasr and Shariati Hospitals in Tehran. Sixty-seven healthy singleton pregnant and 42 pregnant women with diabetes were selected during 26-28 weeks of gestational ages. Glucose tolerance tests (GTT) were performed to evaluate blood glu-coses. Blood glucoses were controlled in diabetic cases very well. Length and width of the placentas were measured using ultrasonography during pregnancy. After termina-tion of pregnancy, placental weights were measured and recorded using weighting scale with 10 gram accuracy by someone who didn't know about diabetes status. Baby weights were measured after birth and initial stabilisation. Results: In this study, there were no significant differences between gestational diabe-tes mellitus (GDM) and healthy groups in Body Mass Index (BMI) factors. There was no statistically significant differences between the mean weight of infants born with gestational diabetes and control groups. There were no statistically significant differ-ences between the mean placental weights between two groups. Ratio of the placental weights to the birth weights between the two groups were not statistically significant. The mean placental length, width and placenta length times by width in two groups had no significant differences, but the mean gravidities in healthy group was 1.7910 and in gestational diabetes mellitus was 1.9762 that are significantly different (P=0.0217). The mean parities respectively were 0.6567 and 0.8100 which was not sig-nificantly different (P=0.0183). Conclusion: The present study has shown there was no significant differences between fetal and placental weights in normal pregnancies and women with controlled gesta-tional diabetes

Evaluating knowledge, attitude, and practice of ergonomics during dental treatment among dental students of Urmia university of medical sciences in 2020

Background and Aims: The objective of this study was to evaluate the knowledge, attitude, and practice of ergonomics during dental treatment among students of Urmia university of medical sciences in 2020. Materials and Methods: In this descriptive-analytical study, self-administered questionnaires were given to 78 dental students of Urmia University in 2020 and the knowledge, attitude, and practice of every participant were evaluated. Demographic data including sex, age, and University grade were recorded as well. Data were analyzed by SPSS software24 with One Way ANOVA and t-test and the significance level of P<0.05. Results: 78 students (44 males and 34 female) by Mean Age 23.9±2.12 were included in the study. The difference between the attitudes of different age groups was significant (P=0.006). The age group of 20 to 24 years had a more positive attitude than other age groups. However, the results of this study did not show a significant r elationship between the participants' knowledge and practice with their age (P>0.05). Conclusion: According to this study, the knowledge, attitude and practice of Urmia dental students were in the desired range. 20-24 year students had significantly higher attitude in comparison to others. Therefore, more endeavors should be taken to improve these parameters in ergonomics

Relationship between Spiritual Health and Academic Achievement among Students of Bushehr University of Medical Sciences

Introduction: Spiritual health is one of the four dimensions of health and it is a way to deal with stress during education. Considering the effect of cultural and geographical factors on both the spiritual health and educational achievement study was done to investigate the relationship between spiritual health and academic achievement of students of Bushehr University of Medical Sciences in the academic year 2018. Methods: This study is a descriptive-analytical and cross Population was 2100 students of Bushehr University of Medical Sciences and the sample size was 330 and they were selected from the fields of medicine, dentistry, paramedical, nursing and health by simple random method. For collection of data, a form of information including demographic variables was used. A self-regulatory in learning and spiritual well-being scale (SWBS) questionnaire was employed. Kruskal-Wallis and Mann-Whitney tests were used to analyze the data. Results: The mean spirituality well-being score was 81.27 ± 17.43, of 120 which 82.4% of the subjects had a moderate score (41-99). Spiritual health and age (P=./0001), academic years (P=./005) gender (P=./0001), place of residence (P=./008) and father's education(P=./012) were among the significant relationships. The mean self-regulation score for learning was 94.91 ± 13.61. There was also a positive and significant correlation between spiritual health and self-regulation in learning (r=./22 , p=./001) Conclusion: Considering the role of spiritual health in positivism, creating relaxation and helping to improve individual performance, it seems that spiritual health needs to be introduced in educational and cultural planning, especially in the field of practice

Fracture resistance of immature teeth filled with mineral trioxide aggregate or calcium-enriched mixture cement: An ex vivo study

Background: The ability of mineral trioxide aggregate (MTA) to strengthen the tooth structure has been studied with contradictory results, and there is a lack of data in the case of Calcium-enriched mixture (CEM) cement as a novel endodontic biomaterial. The aim of the present study was to evaluate the reinforcing effect of MTA and CEM cement on simulated immature teeth. Materials and Methods: This ex vivo study was carried out on a total of 46 human maxillary incisors. Access cavities were prepared. Five teeth were randomly selected as negative control. The root length of the remaining teeth was standardized to 9 mm. Rotary files and peeso reamers were used to enlarge the canals. The prepared specimens were randomly assigned into three experimental (n = 12) and a positive control (n = 5) groups. In groups 1 and 2, the canals were filled with MTA or CEM cement, respectively. In group 3, a 5-mm MTA plug was placed, and the remainder of the canal was filled with composite resin. The canals of the positive control were kept unfilled. After 6 months, the teeth were tested for fracture strength in a universal testing machine. The groups were compared using Univariate analysis of variance (ANOVA). Results: There were significant differences between fracture strength of experimental groups with that of both control groups (P0.05). Conclusion: After 6 months, MTA and CEM cement exhibit distinct reinforcing effect on immature teeth