Comparison of the cyclic fatigue resistance of hyflex EDM, vortex blue, protaper gold, and onecurve nickel-Titanium instruments.

OBJECTIVE: This in vitro study aimed to compare the cyclic fatigue resistance of HyFlex EDM (HEDM), Vortex Blue (VB), ProTaper Gold (PG), and OneCurve (OC) nickel-titanium (NiTi) instruments. MATERIALS AND METHODS: About 12 HEDM (25/.~), 12 VB (25/.06), 12 PG (25/.08), and 12°C (25/.06) instruments were included in this study. All the instruments were tested with a 60° angle of curvature and a 3-mm radius of curvature. All the instruments were utilized until fracture occurred, and then the number of cycles to failure (NCF) was calculated. The data were analyzed statistically using Kruskal-Wallis H and Mann-Whitney U-tests. The statistical significance level was set at P < 0.05. RESULTS: HEDM instruments had the highest cyclic fatigue resistance among all the other instruments (P < 0.05). The OC instruments had a significantly higher fatigue resistance than the PG and VB instruments (P < 0.05); however, there was no significant difference between PG and VB instruments in the NCF (P > 0.05). CONCLUSION: Within the limitations of this in vitro study, it was found that the cyclic fatigue resistance was higher for the HEDM instruments than for the VB, PG, and OC instruments.

A proposal for a problem-oriented pharmacobiochemistry course in dental education.

Problem-oriented learning is an effective method of learning that increases students' learning motivation, improves the relationship amongst students and results in open-minded discussions. In this study, a new problem-oriented pharmacobiochemistry course related to 'oxidative metabolism of drugs by cytochrome P450 (CYP450) systems' was designed. Students were divided into seven groups. Three keywords related to drug interaction through CYP450 were provided to each group in order for them to conduct research on the information given. After 1 month, the groups attended a session under the supervision of a tutor to solve a simulated problem case that was designed using the keywords. At the end of the integrated course, a multiple-choice examination was given. The success rate of 76 students who attended the course was found to be significantly higher than the success rate of the students who received the lecture-based course only (P < 0.0001). A questionnaire containing 20 items (Cronbach's alpha: 0.92) was administered to the students to learn about their perception regarding this educational model. The questionnaire was evaluated using the Likert scale. Student feedback was very positive, with fourteen answers rated as 'agree' and the remaining six rated as 'strongly agree'. Students thought that the problem-oriented model was very enjoyable and useful in regard to dental education. Based on these results, we conclude that this course model may help achieve an integrated curriculum for dental school programmes.

Effect of three different remineralizing agents on artificial erosive lesions of primary teeth.

BACKGROUND: This study aimed to investigate the efficacy of three remineralizing agents on dental erosion in primary teeth. METHODS: Forty primary molars were randomly divided into four groups (n = 10 each): self-assembling peptide (P11-4 ), casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP), sodium fluoride (NaF) and artificial saliva (AS; control). The erosion-like formation was created by immersing the samples in citric acid (4 × 2 min, pH 2.3) and AS (4 × 2 h, pH 7). The eroded samples were then treated with remineralizing agents and subjected to further erosion consisting of 15 cycles (3x/8-h interval) of immersion in citric acid and AS for 6 s each. Alterations in the mineral content and morphology of the samples were quantified using a microhardness tester and atomic force microscope. RESULTS: All agents had a significant remineralization effect on eroded primary tooth enamel. After further erosive challenge, enamel loss in the CPP-ACFP group was found to be significantly lower than in all other groups, and no significant difference was found between the P11-4 and NaF groups. CONCLUSIONS: This study showed that all tested materials had remineralization ability, and CPP-ACFP had a superior effect in inhibiting enamel loss due to dental erosion in primary teeth. © 2022 Australian Dental Association.

The importance of student research projects in dental education.

In this article, our aim was to summarise students' research over 15 years at Istanbul University Faculty of Dentistry and to evaluate both the research activities from the students' perspectives and the effect of this activity on their undergraduate and postgraduate success. In 1992, dental students formed 'a Student Research Club' (SRC), which new students attend voluntarily and carry out a scientific project out with the normal curriculum every year. In total, 409 different students have presented 193 research projects at these meetings over 15 years. Seventy-four of these students were from other universities and presented 37 projects. In this research, a questionnaire containing 20 items was administered to 93 students who were the members of SRC to learn their own perception of the development of their academic and research skills and the broader impact of the club on their career. It was evaluated using Likert scale (ranged from strongly disagree to strongly agree). Student feedback was very positive and over three quarters (81%) of answers ranged between 'agree' and 'strongly agree'. When the cumulative grade point average (CGPA) of the 88 SRC members in the last 6 years (2003/2004 to 2008/2009) was evaluated as the school success rate, significant difference was found between the grades obtained by members and non-members (P<0.001). There was also significant difference between the CGPA of 25 members of SRC who were randomly chosen, before and after membership to the club (P<0.001). While the 141 members of SRC applied to postgraduate education to Istanbul University Faculty of Dentistry over the last 5 years, 74 of them accepted for PhD (52.6%). There is a statistically significant difference between the member and non-member groups (P<0.001). In addition, of the 58 teaching assistants who stayed in academic life after postgraduate studies at Istanbul University Faculty of Dentistry, 16 of them had been a member of the SRC (31%). However, no statistical difference was found between members of SRC and non-members. These data showed that although the students had an intensive programme in the school, they were able to carry out this voluntary activity successfully and this activity contributed to their educational process. Students also believe that participation of them to this activity effects positively on both personal development and academic success.

A study on neonatal factors and eruption time of primary teeth.

OBJECTIVE: The purpose of this study was to determine the time of the eruption of the first primary tooth (FPT) in infants and to assess the effects of neonatal factors on the timing of the eruption. BASIC RESEARCH DESIGN: The dental and medical records of healthy infants were reviewed to gather data on birth weight (BW), gestational age (GA), prenatal history, and the time of the eruption of the FPT. Additionally, the mothers of these infants were asked to identify their smoking habits and/or caffeine consumption during pregnancy through face-to-face interviews. The resulting data were statistically analysed with the Student's t, Tukey, and Pearson correlation tests. RESULTS: The mean eruption times (MET) for girls and boys were 7.25 +/- 2.47 and 7.07 +/- 1.66 months respectively (p > 0.05). The MET of the FPT in infants with a GA of less than 34 weeks, 34 to 37 weeks, or over 37 weeks were 8.0 +/- 2.0, 8.29 +/- 2.97, 6.93 +/- 1.87 months, respectively. The MET in infants with a BW of 1500 to 2500g was 8.28 +/- 2.28 months, while the MET for the infants with a BW of over 2500g was 6.99 +/- 1.94 (p = 0.014). CONCLUSION: A significant difference was found in the METs of infants with low and normal BWs. No significant differences were observed in the MET as related to other neonatal factors.

The effect of heat-stable extract from bovine sublingual salivary glands on the carbohydrate metabolism of the rabbit.

This extract (SLF3) caused hyperglycaemia when injected intraperitoneally (i.p.) into rabbits (20 mg/kg body wt) which was maximal at 0.5 h and took 2 h to return to the initial value. SLF3 also produced a two-fold increase in corticosteroid levels compared to controls, so the increase in blood glucose was probably mediated by adrenal cortical hormone stimulation.

The effect of toxic doses of cholecalciferol (vitamin D3) on the serum zinc levels in rats.

Zinc is a trace element important to bone mineralization as well as, in general, nutrition. It is known that cholecalciferol (vitamin D3) affects bone metabolism. In this study, toxic doses of vitamin D3 were injected subcutaneously (25 micrograms/d) to rats for 5 wk. It caused a significant increase in serum zinc levels (p < 0.02). On the other hand, no significant increase was detected in the other groups. Excessive amounts of vitamin D3 caused bone breakdown and increased the levels of zinc in blood.

Artificially formed caries-like lesions around Class II glass ionomer restorations in primary molars.

The aim of this study was to investigate the microleakage around Class II glass ionomer restorations in primary molars. Two different glass ionomer cements and one amalgam control were assessed in vitro by acidified gel technique. Assessment of caries-like lesions was performed using polarized light microscopy. The traditional glass ionomer (Chemfil II) with dentin conditioner provided the highest protection against caries attack and the amalgam restorations provided the least.

Acute lymphoblastic leukemia: dental health of children in maintenance therapy.

The dental health of 41 children aged 4-16 years who were in maintenance therapy from acute lymphoblastic leukemia (ALL) was examined in relation to the period of time in maintenance. There was no significant difference in dental experience and salivary flow rate between the control group and patients with leukemia. Performed treatment index (PTI) and required treatment index (RTI) scores reflected that children, who were in maintenance therapy had insufficient dental care and needed more dental treatments. A statistically significant difference in salivary pH was found between the children, who were in maintenance therapy for 12-24 months and less than 12 months and also the control group; but the pH scores of all groups were observed in normal limits.

Future perspectives of anatomy in dental education: quo vadis? / Perspectivas futuras de la anatomía en la educación dental: ¿quo vadis?

Anatomists have become familiar with an ongoing debate about the integration of basic sciences into the clinical context or vice versa. Although various educational modalities in dental school curricula and changes in curricular strategies challenge anatomists, the priorities in teaching anatomy and the emergency of presenting fundamental concepts in order to integrate students' basic science skills into the clinic led educators to develop new teaching methods. A search for improved efficiency and impact of the presentation of knowledge to the students in order to foster positive feedback should be one of the major responsibilities of the educators in basic sciences. New gold standards, such as computer-based learning tools and computer-assisted instruction laboratories, may provide trigger points for the perception of the audience in dental faculties. In the light of these considerations, Anatomy Society should rapidly communicate future perspectives.

Los anatomistas comenzaron a familiarizarse con un debate sobre la integración de las ciencias básicas en el contexto clínico, o viceversa. Aunque diversas modalidades educativas en los programas de la escuela de odontología y estrategias del plan de estudios anatómicos han cambiado, las prioridades en la enseñanza de la anatomía y la emergencia de presentar los conceptos fundamentales para integrar los conocimientos de ciencias básicas de los estudiantes en la clínica de llevar a los educadores a desarrollar nuevos métodos de enseñanza. La búsqueda en la mejora de la eficiencia y el impacto de la presentación de los conocimientos a los estudiantes con el fin de originar en la evaluación una retroalimentación positiva debe ser una de las principales responsabilidades de los educadores en ciencias básicas. Los nuevos gold standarts, como herramientas informáticas de aprendizaje y laboratorios de instrucción asistida por computadora pueden ser los puntos gatillo para la percepción de la audiencia en las facultades de odontología. A la luz de estas consideraciones, la Sociedad Anatómica debe designar urgentemente perspectivas futuras.

The effect of heat-stable extract from bovine sublingual salivary gland on serum cholesterol and triglyceride levels in normal and hypercholesterolemic rabbits.

An extract of bovine sublingual glands (SLF3) reduced the serum cholesterol levels of normal rabbits 34.6% and serum triglyceride levels 19.6% when injected intraperitoneally (i.p.) at 20 mg/kg body wt on alternate days for 7 days. SLF3 also reduced serum cholesterol levels 69.0% and triglyceride levels 46.5% in hypercholesterolemic rabbits, while in similar rabbits injected with a control muscle tissue extract, the rate of decrease in serum cholesterol levels was 33.3% and triglyceride levels 26.7%.

Effect of toxic doses of cholecalciferol (vitamin D3) on alkaline phosphatase levels in serum and gingival tissues of rats.

Toxic doses of cholecalciferol (vitamin D3) were injected subcutaneously (25 micrograms/day) into rats for 5 weeks, causing a significant increase of serum alkaline phosphatase (ALP) levels (p less than 0.01). Gingival tissue alkaline phosphatase levels were also elevated (p less than 0.01). On the other hand, a significant difference was detected between serum calcium levels in experimental and control groups (p less than 0.02).

Salivary peroxidase activity in whole saliva of patients with insulin-dependent (type-1) diabetes mellitus.

In this study, salivary peroxidase activity was measured in a group of 10 patients with insulin-dependent (type I) diabetes mellitus (IDDM) who had a tendency towards periodontitis. In healthy subjects (N : 10), mean salivary peroxidase activity was 0.0025 +/- 0.001 IU/ml, while in this group of type I diabetic patients it was 0.051 +/- 0.015 IU/ml, a significantly higher level (p < 0.001). Approximal plaque index (API), modified sulcus bleeding index (mod SBI) and pocket depths were assessed clinically. The values for mod SBI and API were 60% and 68% respectively for the diabetic patients while for the control group mod SBI was measured 0.0% and the value for API was 10.67% (p < 0.001). The administration of this simple and practical test may provide an early marker of a tendency towards periodontitis in IDDM patients.

Fluoride concentration and profile in different cementum surfaces.

This study was performed to determine the fluoride concentration of the various cementum surfaces in different tooth groups to find out the most proper teeth and tooth surfaces for different cementum studies. For this purpose, direct measurements of phosphorus and fluoride were carried out in an acid etch biopsy solution. The findings indicate that incisors with exposed cementum are the most inappropriate teeth in comparison with the other groups. According to the results obtained it may be recommended that the studies related to fluoride uptake for cementum should be performed on teeth with no gingival recession or on the unerupted teeth.