Introduction: The purpose of this study was to decide on the relation between types of mixing and the porosity of diameter (1-100) µm and compressive strength of RMGIC. Methods: Fifteen specimens 6mm height and 4mm in diameter were prepared for each type of luting cement and were stored in distilled water at 37° C for 24 hours. The compressive strength was determined. The fractured surfaces of 10 randomly selected specimens of each cement type were analyzed using SEM at 250 times magnification, and five photomicrographs were taken at five random places. All the photomicrographs were analyzed using image analyzer software to determine the amount and size of porosity present. Results: There was no significant difference in compressive strength between different mixing methods, but it had a significant impact by increasing the percentage of porosity of diameter (1-100) µm in diameter of RMGIC. There was no linear relationship between compressive strength and porosity (1-100) µm in diameter for both types of luting cements (P>0.05). Conclusion: No significant differences in compressive strength were found using different mixing methods. The size and number of porosity in the specimens of encapsulated cements were greater than those of hand-mixed cements. The porosity (1-100) µm in diameter and the compressive strength bore no linear relationship to each other.
Objective: To evaluate the root debridement skill in periodontology pre-clinical module among dental students and to estimate the effectiveness of conducting periodontology pre-clinical module before entering clinical module. Materials and Method: : A total of 47 pre-clinical dental students (Year 2) were included in this study. Single rooted extracted teeth were collected, mounted on acrylic resin and set into the level of 1/3 of the root length. Each of them were instructed to prepare a mounted teeth and to perform root debridement procedure on the labial surface of the tooth only within 10 minutes using Gracey curette #5/6. The similar samples were distributed back to the same students (which were already in clinical year (year 4) to repeat the same procedure on the lingual surface of the same tooth. Root surface roughness was evaluated by using scanning electron microscope (SEM) and profilometer for both labial and lingual surfaces. Statistical analysis was done using Mann-Whitney U test and T-test. Significance level of p ≤ 0.05 was assumed for all analysis. Results: SEM photomicrographs of root surfaces with magnifications of 100x and 800x revealed that there were incomplete removal of the dental calculus in both surfaces and significant roughness root surfaces noted. Conclusion: : No significant differences noted between the students’ root debridement skill in the pre-clinical and also clinical year. Objectives of the current module were fulfilled but in order to meet the highest standard, current module need to be improved in the future.
Background: Fluoride is needed for the normal development of bone and teeth; in high levels, it affects developing teeth and bone. Dental fluorosis (DF) is caused by ingestion of excess fluoride mainly through drinking water.
Aim: The present study aims to observe and understand the histological changes of fluorosed teeth under light microscope (LM).
Materials and Methods: Teeth which were indicated for extractions for orthodontic or periodontal problems were selected. Thirty extracted teeth were selected with varying degrees of DF based on modified Dean's fluorosis index. Ground sections of these teeth were prepared and the sections were studied under binocular LM. Photomicrographs were taken under high power objective using 15 megapixels Nikon camera.
Results and Conclusion: Qualitative histologic changes in different grades of fluorosed teeth were evaluated in enamel, dentin, cementum and between their junctions. Fluoride interacts with enamel in both mineral phases and organic macromolecules by strong ionic and hydrogen bonds resulting in incomplete crystal growth at prism peripheries. This presents as hypomineralization of enamel and dentin, increased interglobular dentin, increased secondary curvatures and changes in cementum such as diffuse cementodentinal junction and increased thickness of Tomes' granular layer. Changes in the structure of the teeth with Dean's index below 2 and teeth with Dean's index of 2 and above were compared using Chi-square test. P value was found to be highly significant being 0.00047. Many of the features of dental fluorosis seen in the present study under light microscope are comparable to those results studied under specialized microscopes.
Rhino-orbito-cerebral mucormycosis is a fungal infection that can be fatal especially in immunocompromised patients. It is extremely rare in immunocompetent individuals. We describe here an immunocompetent patient who survived rhino-orbito-cerebral mucormycosis due to Saksenaea vasiformis, and provide a literature review of this rare entity.