Effects of different powder to liquid ratios on the push out bond strength of CEM cement on simulated perforations in the furcal area

Proper bond strength to dentin is one of the properties of biomaterials used for therapeutic purposes such as repair of furcal perforations. The aim of the present study to evaluate the effects of different powder to liquid ratios of Calcium-enriched mixture (CEM) on the push-out bond strengths in simulated perforations in the furcal area and compare it with Mineral trioxide aggregate (MTA). Furcal perforations, measuring 1.3 mm in diameter and 2 mm in height, were prepared in 120 mandibular first molars. Then the samples were randomly assigned to two groups (n=60). MTA and CEM cement were used for the repair of perforations in groups 1 and 2, respectively. Each group was divided into 3 subgroups based on the powder to liquid rations as follows: subgroup 1 (W/P) , 1:2; subgroup 2, 1:3; and subgroup 3, 1:4. After mixing and placing the materials in the perforation area, the samples were placed in closed containers at 37°C and 100% relative humidity for one week. A universal testing machine was used to determine the bond strength values. After recording the standard deviations, data were analyzed with two-way ANOVA. Statistical significance was set at P<0.05. In the MTA and CEM groups the highest push-out bond strength values were recorded in the third (W/P: 1:4) and first (W/P: 1:2) subgroups, respectively. There were significant differences in both groups between the ratios mentioned above and the other ratios (P<0.05). Under the limitations of the present study, an increase in the powder-to-liquid ratio in CEM cement resulted in a decrease in bond strength, contrary to MTA

Antimicrobial efficacy of different concentration of sodium hypochlorite on the biofilm of Enterococcus faecalis at different stages of development

Persistent infection of the root canal due to the presence of resistance bacterial species, such as Enterococcus faecalis, has always been one of the most important reasons for endodontic treatment failure. This study investigated the antimicrobial efficacy of 1%, 2.5 % and 5% sodium hypochlorite in eliminating E. faecalis biofilms at different stages of development. In this study 4-, 6- and 10-week-old E. faecalis biofilms were subjected to one of the following approaches: phosphate-buffered saline solution (PBS) or 1%, 2.5% and 5% NaOCl. Dentin chip suspensions were used for colony forming unit (CFU) counting to estimate remaining E. faecalis counts. Statistical comparison of the means was carried out with Kruskal-Wallis test, and pair-wise comparisons were made by Mann-Whitney U test, at a significance level of P<0.05. The results showed that 2.5% and 5% NaOCl completely eliminated E. faecalis biofilms in three stages of biofilm development, whereas 1% NaOCl resulted in 85.73%, 81.88% and 78.62% decreases in bacterial counts in 4-, 6- and 10-week-old biofilms, respectively, which was significantly more than those with PBS (p<0.05). The bacteria in mature and old biofilms were more resistant to 1% NaOCl than were the bacteria in young biofilms. Overall survival rate and residual bacteria increased with biofilm aging

Effects of different intra canal medicaments on the push out bond strength of endodontic sealers

One of the essential properties of the root canal sealers is the adhesion to root canal dentin and their higher bond strength decreases the microleakage. The aim of the present study was to compare the effect of Different Intracanal medicaments on the push out bond strength of AH26 and MTA Fillapex sealers. A total of 104 one-rooted extracted human teeth were divided into 4 (n=26) experimental groups. After the cleaning and shaping, the root canals were filled with Ca(OH)2, triantibiotic paste (TAP), Metapex or 2% chlorhexidine gel for two weeks. Then, intracanal medicaments were rinsed away and the samples in the sub-groups were obturated with gutta-percha and AH26 or MTA Fillapex sealers. After two weeks incubation, 2-mm-thick middle section of each root was then subjected to push-out testing. Data were analyzed with two-way ANOVA and LSD test. With all the intracanal medicaments, the overall mean of bond strength values were significantly higher with AH26 compared to MTA Fillapex (p<0.05). With the use of MTA Fillapex the maximum and minimum means of bond strength values were recorded with CHX and Metapex and for AH26 were recorded with Ca(OH)2 and chlorhexidine, respectively. The bond strengths of sealers to dentin are under the influence of pre-treatment with intracanal medicaments. Under the limitations of the present study, the effect of TAP on the bond strength of endodontic sealers was not negative

Study of the Impacts of Educational Technology on Academic Progress of Students in Bamian Boys’ Center High School

The aim of this research was to study the impact of educational technology on the academic progress of Bamyan boys’ high school students in 1401 (2022). This research was applied in terms of purpose and a descriptive survey in terms of nature. Societal statistics of this research were the whole of 83 teachers at Bamian Boys’ High School. So, from the societal statistics, we used simple random sampling with confidence levels of 95% and 5% error for 70 people selected according to Morgan’s table and 64 of them answered the questionnaires. For data collection, a questionnaire measuring the attitude towards the use of technology in education (including 50 questions) was specially prepared for teachers and fixed to check their academic progress. SPSS 24 statistical software was used in data analysis. The research outcome indicates factors like the teacher’s understanding and the benefits of implementing educational technology and equipment’s effects on the academic progress of school students. The result means that a spiritual relationship exists between educational technology and the academic progress of students

Smear layer removal evaluation of different protocol of Bio Race file and XP- endo Finisher file in corporation with EDTA 17% and NaOCl

The aim of the present study was to compare the amount of the smear layer remaining in prepared root canals with different protocols of Bio RaCe files and XP-endo Finisher file (XPF) in association with 17% EDTA and sodium hypochlorite solution. A total of 68 extracted single-rooted teeth were randomly divided into 4 experimental groups (n=14) and two control groups (n=6). The root canals were prepared with Bio RaCe files (FKG Dentaire, Switzerland) using the crown-down technique based on manufacturer?s instructions and irrigated according to the following irrigation techniques: Group 1: XPF with 2 mL of 2.5% NaOCl for 1 minute. Group 2:, XPF with 1 mL of 17% EDTA for one minute. Group 3: XPF was used for 1 minute in association with normal saline solution. Group 4: XP-endo Finisher file for 30 seconds in association with 2.5% NaOCl and 17% EDTA for 30 seconds. The negative control group: NaOCl (2.5%) was used during root canal preparation, followed by irrigation with 17% EDTA at the end of root canal preparation. The positive control group: Normal saline solution was used for irrigation during root canal preparation. In all the groups, during preparation of the root canals with Bio RaCe file, 20 mL of 2.5% NaOCl was used for root canal irrigation and at the end of the procedural steps 20 mL of normal saline solution was used as a final irrigant. The samples were analyzed under SEM at ×1000?2000 magnification and evaluated using Torabinejad scoring system. Data were analyzed with non-parametric Kruskal-Wallis test and post hoc Mann-Whitney U test, using SPSS. Statistical significant was defined at P<0.05. The results of the study showed the least amount of the smear layer at coronal, middle and apical thirds of the root canals in groups 2, which was not significantly different from the negative control group (P<0.5). Under the limitations of the present study, use of a combination of NaOCl and EDTA in association with XPF exhibited the best efficacy for the removal of the smear layer

Effect of Calcium Hydroxide on the Push-out Bond Strength of Endodontic Biomaterials in Simulated Furcation Perforations

Introduction: The aim of this in vitro study was to evaluate the effect of calcium hydroxide (CH) on push-out bond strength of white mineral trioxide aggregate (WMTA) and calcium-enriched mixture (CEM) cement in simulated furcation perforations. Methods and Materials: Furcation perforations, measuring 1.3 mm in diameter and 2 mm in height, were created in 80 human mandibular first molars. The teeth were then divided into 4 groups (n=20). In groups 1 and 3 CH was placed in the perforation for one week, before placement of WMTA and CEM. In groups 2 and 4 perforations were repaired without placement of CH. In groups 1 and 2 the perforation sites were repaired with WMTA and CEM cement was used in groups 3 and 4. After 7 days, the push-out test was carried out using a universal testing machine. Data were analyzed with two-way ANOVA. The level of significance was set at 0.05. Results: The maximum and minimum bond strength values were recorded in the WMTA/CH (13.08±1.8 MPa) and CEM cement groups (8.03±0.98 MPa), respectively. There were significant differences in resistance to dislodgement between the WMTA/CH and other groups (P&lt;0.05). Conclusion: Placement of CH before placement of WMTA in furcation perforation improves the push-out bond strength of this material.Keywords: Calcium-Enriched Mixture; Calcium Hydroxide; Furcation Perforation; Mineral Trioxide Aggregate; Push-Ou

Prevalence of Psychiatric Disorders among Children and Adolescents: A Study from Khuzestan

&nbsp; Objective This cross-sectional study aimed to study the prevalence rate of psychiatric disorders in children and adolescents in Khuzestan province. Materials &amp; Methods A community sample consisting of 1028 (51.6% female) children and adolescents aged 6-18 years was selected using a multistage cluster sampling method. Data were gathered using the Kiddie-SADSPresent and Lifetime Version (K-SADS-PL) and a demographic questionnaire (i.e., gender, age, level of education, place of residence, parent’s education, and parent’s Job) Results Nearly 22.6% (22.3% of boys and 23% of girls) of all participants suffered from at least one psychiatric disorder. There was no significant difference in the prevalence of psychiatric disorders based on gender, age, father’s education, mother’s education, mother’s job, and father’s job (all p&gt;0.05). Psychiatric disorders were significantlymore prevalent among children and adolescents in urban areas compared to rural places (2.9% vs. 8.1; p&lt;0.001). The most prevalent category was anxiety disorders (15%). Also, the most common disorders were specific phobia (7%), separation anxiety disorder (6.3%), and enuresis (5.2%). The most common comorbid disorders were mood disorders and anxiety disorders (56.3%), followed by anxiety disorders and elimination disorders (32.1%). ConclusionPsychiatric conditions are prevalent in children and adolescents living in Khuzestanian. The study’s findings have important implications for providing effective psychiatric services. &nbsp; &nbsp

A Review on Root Anatomy and Canal Configuration of the Maxillary Second Molars

Introduction: The complexity of the root canal system presents a challenge for the practitioner. This systematic review evaluated the papers published in the field of root canal anatomy and configuration of the root canal system in permanent maxillary second molars. Methods and Materials: All articles related to the root morphology and root canal anatomy of the permanent maxillary second molars were collected by suitable keywords from PubMed database. The exhaustive search included all publications from 1981 to December 2015. The articles relevant to the study were evaluated and data was extracted. The author/year of publication, country, number of the evaluated teeth, type of study (method of the evaluation), number of roots and the canals, type of canals and the morphology of the apical foramen was noted. Results: The highest studied populations were in Brazil and United States. A total of 116 related papers were found, which had investigated 11945 teeth in total. Across all the studied populations, the three-rooted anatomy was most common, while the four-rooted anatomy had the lowest prevalence. The presence of the second mesiobuccal canal ranged from 11.53 % to 93.7%, where type II (2-1) configuration was the predominant type in Brazil and USA and types II and III (1-2-1) in Chinese populations. In 8.8-44% of cases, fusion was observed. The main reported cases were related to palatal root. The major method of anatomical investigation in case reports was periapical radiography, and the chief method in morphological studies was CBCT. Conclusion: The clinicians should be aware of normal morphology and anatomic variations to reduce the treatment failure.Keywords: Maxillary Second Molar; Root Canal Anatomy; Root Morphology; Systematic Revie

Studying the Prevalence of Organizational Indifference in Bamyan University

This research was conducted with the aim of investigating the prevalence of organizational indifference in Bamyan University. The research method was a descriptive method. The statistical population included all lecturers and employees of Bamyan University, whose total number reached (269). In this research, full sampling method was used and all members of the statistical community were selected as statistical samples. To collect data, organizational indifference questionnaire of Danaeefard, Hassanzadeh and Salarieh (2010) was used. The validity of the questionnaire was calculated using the item analysis method and its reliability was calculated using Cronbach's alpha scale, and its alpha coefficient was obtained (0.914). This questionnaire was sent to 269 people, of whom (214) responded. The data obtained at two levels (descriptive and inferential) were analyzed using the statistical methods of Pearson's correlation coefficient, one-sample t-test and IBM SPSS23 statistical software. The results of data analysis showed that the prevalence of organizational indifference and its dimensions are less than average level (Q2=3) and more than low level (Q1=2)

Effects of Chlorhexidine and Sodium Hypochlorite on the Setting Time of Calcium-Enriched Mixture Cement

Introduction: The aim of the present study was to evaluate whether adding 2% chlorhexidine (CHX) and 2.6% sodium hypochlorite (NaOCl) to calcium-enriched mixture (CEM) cement would affect its setting time (ST), or not. Methods and Materials: In this study, the setting time of CEM cement was evaluated in three groups (n=9) as follows: group 1; CEM cement, group 2; CEM cement+2% CHX and group 3; CEM cement+2.6% NaOCl. Then the mean values of ST were calculated and the Kolmogorov-Smirnov test was used to evaluate the normal distribution of data. The Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis. Statistical significance was set at 0.05. Results: The mean ST for groups 1, 2 and 3 were 105, 120 and 220 min, respectively. There was a significant increase in the duration of ST in group 3 (NaOCl) in comparison with the two other groups (P&lt;0.05). Conclusion: NaOCl significantly increased the ST of CEM cement, whereas chlorhexidine did not alter the ST.Keywords: Calcium-Enriched Mixture; CEM Cement; Chlorhexidine; Setting Time; Sodium Hypochlorit