ABSTRACT
Objective: among the various impression materials, for alginate tear strength is probably more important than the compressive strength. The tear strength is important when an impression involves a mechanical undercut and/or lacks bulk strength to resist tearing. This study evaluated tear strength of Iralgin and compared it with tear strength of Alginoplast
Methods: in this invitro experimental study A mold was made with 100mm×20mm×1mm dimensions and a longitudinal prominence in 0.3 mm depth. Twenty-seven specimens [9 Super Iralgin, 9 Pocket Iralgin, and 9 Alginoplast] were selected non-randomizedly. Each specimen prepared corresponding to manufacturer and injected into the mold. And the mold was placed under press. After removing the mold from press, every specimen formed as a trouser-shaped specimen. The specimen was pulled in tensile machine with 50 mm/min speed. The data of specimens in different groups were statistically analyzed using one-way ANOVA, Kolmogorov- Smirnov, and Levene's tests
Results: mean of tear strength in first specimen [Super Iralgin], second specimen [Pocket Iralgin], and third specimen [Alginoplast] were 640+/-38 grf/cm[2], 500 +/-20grf/cm[2], and 1100+/-27 grf/cm[2] respectively. According to ANOVA test, the mean of tear strength was not equal in three specimens [p<0.01]. According to LSD Multiple Comparison, the first and second specimens were same in tear strength, whereas the third specimen was different from the two former [p<0.05 and p<0.01]
Conclusion: super Iralgin and pocket Iralgin were the same in tear strength. Alginoplast was significantly higher than super and pocket Iralgin in tear strength
ABSTRACT
Statement of the Problem: Advances in computer science and technology allow the instructors to use instructional multimedia programs to enhance the process of learning for dental students
Purpose: The purpose of this study was to determine the effect of a new educational modality by using videotapes on the performance of dental students in preclinical course of complete denture fabrication
Materials and Method: This quasi-experimental study was performed on 54 junior dental students in Shahid Beheshti University of Medical Sciences [SBMU]. Twenty-five and 29 students were evaluated in two consecutive semesters as controls and cases, respectively for the same course. The two groups were matched in terms of "knowledge about complete denture fabrication" and "basic dental skills" using a written test and a practical exam, respectively. After the intervention, performance and clinical skills of students were assessed in 8 steps. Eventually, a post-test was carried out to find changes in knowledge and skills of students in this regard
Results: In the two groups with the same baseline level of knowledge and skills, independent T-test showed that students in the test group had a significantly superior performance in primary impression taking [p= 0.001] and primary cast fabrication [p= 0.001]. In terms of anterior teeth set up, students in the control group had a significantly better performance [p= 0.001]
Conclusion: Instructional videotapes can aid in teaching fabrication of complete denture and are as effective as the traditional teaching system
ABSTRACT
Objectives: Microtia is the most commonly seen congenital ear defect, and involves an auricular deformity either unilaterally or bilaterally. The aim of this study was to fabricate silicone prostheses for a child with bilateral microtia using an innovative technique.
Methods: This method involved the construction of bilateral ear prostheses using clips, which were located within the layers of the silicone superstructure.
Results: Surgical reconstruction was not indicated due to the patient's age; so prosthetic reconstruction was advised in this case.
Discussion: Two prosthetic ears were manufactured, with one being attached using an adhesive method and the other by a self suspension method. The child and his parents were very satisfied by the cosmetic and aesthetic appearance of the prostheses fitted. This technique has been proven to be suitable for pediatric patients with microtia
ABSTRACT
Denture cleansing is a key element in retaining mucosa free of any inflammation. However, many denture users usually ignore this important factor. This investigation was designed to compare the efficacy of a denture brush and an ordinary brush in cleansing process of complete dentures. A group of 31 individuals aged 44-76 years were included in this study. Each patient was then instructed to use the denture brush for a period of 4 weeks while an ordinary brush was to be used for the following 4 weeks. Dentures were photographed and evaluated at every two week intervals using a computer photographic software assessment method. Pictures were compared using the image tool for plaque remaining on the denture surfaces. Student t-test was used to analyse data collected. Comparison of the brush type efficacy at 2 and 4 weeks did not show any significant difference [P>0.05], however, clinical evaluation indicated that denture brush leaves much less plaque bio-film compare to the ordinary one, with mean plaque traced at 6.88 to 9.24 in 4 weeks. There were no significant differences found between the two brushes' efficacy, with clinical evaluation significantly in favor of denture brush