scholarly journals Detection of Root Canal Isthmuses in Molars by Map-Reading Dynamic using CBCT images

2013 ◽  
Vol 24 (6) ◽  
pp. 569-574 ◽  
Author(s):  
Jesus Djalma Pecora ◽  
Carlos Estrela ◽  
Mike Reis Bueno ◽  
Olavo Cesar Porto ◽  
Ana Helena Goncalves Alencar ◽  
...  

The aim of this study was to detect root isthmuses in maxillary and mandibular molars and evaluate their frequencies using map-reading dynamics in CBCT images. Two hundred extracted human maxillary and mandibular molars were used in ex vivo assay. A consecutive sample of two hundred maxillary and mandibular molars (first and second) was selected from CBCT exams. The isthmuses were detected from the pulp orifice to the apex and were recorded according to their beginning and their end, into categories: 1. begin and end in cervical third; 2. beginning in cervical third and end in middle third; 3. beginning in cervical third and end in apical third; 4. beginning and end in middle third; 5. begin in middle third and end in apical third; 6. beginning and end in apical third; 7. no isthmus. The scans were obtained in different planes with map-reading in axial slices of 0.5 mm/0.5 mm involved the coronal to apical direction. The frequencies of isthmus were analyzed according to the level of root and evaluated by Chi-square test. The level of significance was set at α=0.05. The presence of isthmus detected in maxillary molars was 86% in ex vivo assay and 62% in vivo assay, whereas in mandibular molars was observed 70% in ex vivo assay and 72% in vivo assay. The frequency of isthmus was high in both study models. The map-reading dynamics in CBCT images was found to be precise to detect the localization of isthmus.

1977 ◽  
Vol 37 (01) ◽  
pp. 154-161 ◽  
Author(s):  
B. A Janik ◽  
S. E Papaioannou

SummaryUrokinase, streptokinase, Brinase, trypsin, and SN 687, a bacterial exoprotease, have been evaluated in an ex vivo assay system. These enzymes were injected into rabbits and the fibrinolytic activity as well as other coagulation parameters were measured by in vitro techniques. Dose-response correlations have been made using the euglobulin lysis time as a measure of fibrinolytic activity and the 50% effective dose has been determined for each enzyme. Loading doses, equal to four times the 50% effective dose, were administered to monitor potential toxicity revealing that Brinase, trypsin, and SN 687 were very toxic at this concentration.Having established the 50% effective dose for each enzyme, further testing was conducted where relevant fibrinolytic and coagulation parameters were measured for up to two days following a 50% effective dose bolus injection of each enzyme. Our results have demonstrated that urokinase and streptokinase are plasminogen activators specifically activating the rabbit fibrinolytic system while Brinase, trypsin and SN 687 increase the general proteolytic activity in vivo.The advantages of this ex vivo assay system for evaluating relative fibrinolytic potencies and side effects for plasminogen activators and fibrinolytic proteases have been discussed.


Author(s):  
Olayinka Stephen Ilesanmi ◽  
Priscilla Onaopemipo Akosile ◽  
Aanuoluwapo Adeyimika Afolabi ◽  
Victor Okoliko Ukwenya

Abstract Background This study aimed to assess the level of trust in the COVID-19 risk communication efforts in Nigeria. Methods We conducted a descriptive cross-sectional study among community members aged 15 years and above in Ondo state in October, 2020. Data were collected using an interviewer-administered questionnaire. Data were analyzed using SPSS version 22. Descriptive statistics were summarized using frequencies. Trust was ranked from “1” implying “Low level of trust” to “7” denoting “High level of trust”. We conducted bivariate Chi-square test on respondents’ level of trust in the Nigeria Centre for Disease Control (NCDC) and socio-demographic characteristics. The level of significance was set at p<0.05. Results Among the 691 respondents, 244 (35.3%) were aged 21 to 29 years, and 304 (51.4%) used the NCDC to obtain COVID-19 knowledge. Overall, 205 (41.8%) had high level of trust in the NCDC. Furthermore, 51 (51.5%) individuals aged 30-39 years had high level of trust in the NCDC (ᵡ2=17.455, p= 0.001). Also, 114 (48.5%) persons who lived with children below 18 years had high level of trust in the NCDC (ᵡ2= 8.266, p= 0.004). Conclusion Policy makers should prioritize the involvement of young and educated persons in COVID-19 risk communication strategies.


2012 ◽  
Vol 23 (3) ◽  
pp. 199-204 ◽  
Author(s):  
Bruno Carvalho de Vasconcelos ◽  
Leonardo de Alencar Matos ◽  
Elilton Cavalcante Pinheiro-Júnior ◽  
Antônio Sérgio Teixeira de Menezes ◽  
Nilton Vivacqua-Gomes

This study evaluated the accuracy of three electronic apex locators (Root ZX, Novapex, and Justy II) in root canal length determinations using different apical file sizes, considering the apical constriction (AC) and the major foramen (MF) as anatomic references. The diameter of the apical foramina of 40 single-rooted teeth was determined by direct visual measurement and the master apical file was established. Electronic measurements were then performed using 3 instruments: the selected master apical file (adjusted file), one size smaller (intermediate file), and two sizes smaller (misfit file). The distances from the tip of files fixed in the canals to the MF and to the AC were measured digitally. Precision at AC and at MF for the misfit, intermediate and adjusted apical files was as follows: 80%/88%/83% and 78%/83%/95% (Root ZX); 80%/85%/80% and 68%/73%/73% (Novapex); and 78%/80%/78% and 65%/78%/70% (Justy II). Considering the mean discrepancies, statistically significant differences were found only for the adjusted file at MF, with Root ZX presenting the best results at MF. The chi-square test showed significant differences between the acceptable measurements at AC and at MF for the Justy II and Novapex (± 0.5 mm) regardless of file adjustment. Under the conditions of the present study, all devices provided acceptable electronic measurements regardless of file adjustment, except for Root ZX which had its performance improved significantly when the precisely fit apical file was used. Justy II and Novapex provided electronic measurements nearest to the AC.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Stefano Martina ◽  
Alessandra Amato ◽  
Paolo Faccioni ◽  
Alfredo Iandolo ◽  
Massimo Amato ◽  
...  

Abstract Background The present study aimed to investigate the patients’ perception of the dental practice during the COVID-19 outbreak, and whether the pandemic will affect the attendance of orthodontic patients at the dental practice. An online questionnaire, including the Patient Health Questionnaire-4 (PHQ-4), was submitted to Italian dental patients with items about their perceived risks when going to the dentist, concerns about continuing orthodontic treatment, and the onset of temporomandibular disorders (TMD). Data were analyzed with a chi-square test and logistic regression analysis. The level of significance was set at P < 0.05. Results A total of 1566 subjects completed the survey, including 486 who were under orthodontic treatment or who had a child in orthodontic treatment. A total of 866 participants (55.3%) thought the risk of contracting the COVID-19 infection was higher in a dental practice; this perception was associated with gender (women more than man), age (over 60 years old) and high levels of distress (P<0.001). However, 894 patients (57.1%) felt comfortable going back to the dentist. Most of the orthodontic patients (84%) would continue their treatment. After the lockdown, there was a slight increase in the frequency of TMD pain (356 versus 334). Conclusions Most of the participants believed that the dental practice is a place at greater risk of contracting COVID-19, even if they continue to go to the dentist. Gender, age, and the level of distress were associated with the increase in the fear of going to the dentist due to COVID-19. Because of the pandemic, 16% of patients undergoing orthodontic treatment would not return to the dental practice to continue their orthodontic treatment after the lockdown. The prevalence of TMD pain in the population increased due to the pandemic.


2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4257
Author(s):  
Alane Pains Oliveira do Monte ◽  
João Bosco Loiola Filho ◽  
Thais Thatiane Dos Santos Souza ◽  
Mayara De Souza Miranda ◽  
Lívia Correia Magalhães ◽  
...  

<p>This study aimed to evaluate the efficacy of adding sucrose in vitrification solution of ovine embryos produced <em>in vivo</em>. Forty Dorper ewes were selected and superovulated. Immediately prior to the embryo collection by laparotomy, a laparoscopy was performed to verify the superovulatory response. The recovered flushing was followed by embryo evaluation and embryos were divided in two experimental groups where embryos from Control group were submitted to a traditional vitrification protocol and embryos from Sucrose group to a modified vitrification protocol with sucrose. After warming, embryos were again divided regarding cryoprotectant removal (Indirect) or not (Direct). The embryo quality was classified as embryos of degrees I (excellent or good), II (regular), III (poor) and IV (dead or degenerate). It was also verified the homogeneity of mass, occurrence of embryonic mass retraction and rupture of pellucid zone. The results were expressed as percentages and were subjected to Chi-square test with P &lt; 0.05. The embryos vitrified in the presence of sucrose had lower proportions of lower-quality embryos after warming (22.20 vs. 44.50%), higher percentages of homogeneous embryos after warming (63.89 vs. 38.89 %) while concerning other parameters there was no difference between these groups. It can be concluded that the addition of 0.4 M sucrose during vitrification improves the embryo quality.</p>


2021 ◽  
Vol 2 (01) ◽  
pp. 50-60
Author(s):  
Yam Prasad Pandeya

Parental factors play vital role in academic attainment of their offspring. Motivation and counseling stimulate someone to take a desired course of action. This paper attempts to explore the perception of children towards their patents in support, involvement, counseling, and motivation on learning mathematics. This study employed survey research design of the quantitative approach. The total population of the study was90 students (15 students from each six schools) enrolled in Grade ix of Sindhuli district in 2019. The data were collected through self-structured questionnaire using three points-Likert scale items. Mean and standard deviation of each item were calculated and Chi-square test at 5% level of significance was used to test the hypothesis. The finding of this study shows that the parents of Sindhuli district are very conscious about the study of their children whatever their educational level. This study suggests that parent involvement is an inseparable component to promote mathematical achievement of their offspring.


2021 ◽  
Vol 2 (Issue 4) ◽  
pp. 66-74
Author(s):  
Simion Kaminyoge Ambakisye

This study investigated on classroom attentiveness of children from home with inter parental violence in Chamwino, Dodoma, Tanzania. The study employed the cross-sectional survey design whereby 312 out of 652 children from five secondary schools were randomly selected to participate by filling the questionnaire. Chi square test was employed to determine the relationship between violence against mothers and children’s attentiveness at the 0.05 level of significance. The results indicated a significant relationship between parental conflicts and lack of pupils’ adequate concentration in learning. The findings further showed that female children whose mothers are accustomed to violence are more inattentive than male children during the teaching and learning processes. The study recommends that effective intervention strategies such as developing training through psycho education within families, schools and the community be in place.


Author(s):  
Nitin Nagesh Kulkarni ◽  
Stephen Ekwaro-Osire ◽  
Paul F. Egan

Abstract 3D printing has enabled new avenues to design and fabricate diverse structures for engineering applications, such as mechanically efficient lattices. Lattices are useful as implants for biological applications for supporting in vivo loads. However, inconsistencies in 3D printing motivates a need to quantify uncertainties contributing to mechanical failure using probabilistic analysis. Here, 50 cubic unit cell lattice samples were printed and tested with designs of 50% porosity, 500-micron beam diameters, and 3.5mm length, width, and height dimensions. The average length, width, and height measurements ranged from 3.47mm to 3.48mm. The precision in printing with a 95% confidence level was greater than 99.8%. Lattice elastic moduli ranged from about 270 MPa to 345 MPa, with a mean of 305 MPa. Probabilistic analyses were conducted with NESSUS software. The distributions of input parameters were determined using a chi-square test. The first-order reliability method was used to calculate the probability of failure and sensitivity of each input parameter. The elastic modulus was the most sensitive among all input parameters, with 57% of the total sensitivity. The study quantified printing inconsistencies and sensitives using empirical evidence and is a significant step forward for designing 3D printed parts for mechanical applications.


2020 ◽  
Vol 9 (1) ◽  
pp. 65-70
Author(s):  
Pashupati Adhikari

 This study presents an attitude of female students studying B.Ed. third year towards physical education and sports within Kathmandu valley. Initially, it was hypothesized that there is no significance difference in attitude of physical education and sports among female students of different campuses. From these 6 campuses, 184 female students were randomly selected. A five-point Likert-type scale was applied for data collection from the selected students who studied in B.Ed. third year. Altogether five opinion statements were used for data collection. It was found that all respondents showed positive attitudes towards physical education and sports. In order to test whether there is significant interdependence in score among the respondents in different perspectives. The chi-square test score was applied as statistical test at the 0.05 level of significance. The chi-test under contingency table: independent of opinion among the respondent, if (χ2>α=0.05 in different degree of freedom) and independent if (χ2≤ α=0.05 in different degree of freedom). For the measurement of attitude for physical education and sports,it has enough evidence in the data to accept alternatives hypothesis; there is relation or interdependence of attitude towards physical education and sports among the respondents. Because, the score is very high among the response of respondent. The study suggests that the university teacher must be accountable to construct professional environment.


Author(s):  
Jorge Nelson da Silva Júnior ◽  
Rafael Lima Kons ◽  
Rodolfo André Dellagrana ◽  
Daniele Detanico

This study aimed to identify types and sites of body injury, location of injury occurrence, and the mechanism and severity of injuries in novice and advanced Brazilian jiu-jitsu (BJJ) athletes. One hundred and eight BJJ athletes took part in this study separated in two groups: advanced (n = 53) and novice (n = 55). Athletes answered a questionnaire concerning regions of injury, locality of occurrence, injury severity and mechanism. Chi square test and a logistic regression analysis were used with the level of significance set at p < 0.05. The main results showed that shoulders and knees were the most injury location reported by novice and advanced athletes. Novice athletes demonstrated higher prevalence of injuries during training sessions (54.5%), whereas advanced athletes reported more injuries during competitions (66.1%). Significant associations between novice and advanced athletes were observed for major joints (p < 0.05). The odds ratio of having injury was 70-87% less for novice versus advanced athletes for the major joints cited. We concluded that BJJ athletes demonstrate high prevalence of injury mainly at knee and shoulder. While risk of injury appeared less in novice, the advanced demonstrated higher number of injuries during competitions as a consequence of injured joint keys. By contrast, novice athletes reported higher number of injuries associated with training sessions as a consequence of overuse.


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