Gliomas are by far the most common primary central nervous system tumours. So far, the most gliomas were reported to derive from CNS and located in cranium. Here we describe a rare case of glioma located in the parotid gland. The possible mechanisms of this tumor and its diagnostic investigation are discussed in the literature.
Background and Aim: The light-cured composites and other restorative materials are quite common in dentistry today. Successful restorations are dependent on the efficiency of the light-curing unit, the intensity of light, and its wavelength. This study evaluated the efficacy of LED light-curing units in private dental clinics in Tehran.
Materials and Methods: In this descriptive cross-sectional study, 320 light-curing devices in different private dental clinics were randomly evaluated. The radiometer (light-testing-meter) measured Light intensity, and also dust on the fan and cracks or scratches on the filter were directly observed. Moreover, the age of the device, the frequency of changing the bulbs and satisfaction of the dentist concerning the light-curing unit were recorded in questionnaires. Data were analyzed for Spearman correlation and t-test using SPSS software with p<0.05 as the level of significance.
Results: The results showed that the intensity of 53.75% units was more than 300 mW/cm2. The power of 30.3% of curing light units was between 200 and 300 mW/cm2, and 15.9% had lower than200 mW/cm2. The light intensity has a negative relation with the age of the unit, frequency of bulb changing, and scratches on the filter and dust on the fan.
Conclusion: The results proved that the light intensity of about 46% of light-curing units, used in private dental practices and clinics, were inadequate. Since factors such as ageing of the light-curing devices, frequency of bulb replacement, increasing the amount of dust on the fan and scratches on the filter reduces the light intensity; therefore, regular quality control of these devices is necessary.
Aims: Good oral health is essential for the well-being of Human being. However lack of knowledge, guidance and poor oral hygiene practices may lead to poor oral hygiene and predispose one to oral health diseases. This study assessed oral health knowledge and behavior related to oral hygiene status among selected secondary school students in Kasese District, Western Uganda.
Study Design: A descriptive cross sectional study was carried out among students from selected secondary schools of Kasese District, Western Uganda. Stratified sampling technique was used to recruit 278 participants among students of the selected secondary schools.
Methodology: Data was collected using closed and open ended questionnaires. The dependent variable was based on the participant’s responses if he/she had any decayed, missing or filled teeth (DMFT). Bivariate analysis was used to compute crude odds ratios for predisposing factors. The significant variables were then included in the multivariate model to obtain adjusted odds ratios for risks factors associated with occurrence of DMFT.
Results: Out of 278 participants interviewed, 108 (38.8%), 95% CI= (0.3325-0.4468) students had DMFT. There was a statistical significant relationship between the level of the knowledge and behavior of the students and their oral health status. For the Students who had never visited a dentist (95% CI; 1.177-3.315, aOR = 1.975, p=0.010) and those who brushed their teeth once a week (95% CI; 1.226-31.161, aOR = 6.180, p=0.027) were found to be more at risk of developing DMFT.
Conclusion: Poor oral health hygiene among secondary school students was significantly associated with frequency of brushing teeth and failure to visit a dentist. There is need to increase oral health education in secondary schools in order to encourage students to visit dentists regularly as well as improving the frequency of brushing teeth as this will positively impact on oral health behaviors and status.
Background: Causes of failures in class V restorations have always been controversial until now since the biomechanical aspects of these restorations have been understood.
Aim: To comparatively evaluate the stress distribution of a class V restoration in a lower first premolar using a two-dimensional plane strain finite element model.
Materials and Methods: The study was done by modelling a mandibular first premolar which was sectioned buccolingually, in the Ansys 14.5 finite element software. A 100N eccentric load was applied on the tooth structure and stresses were observed at the peripheries of the class V restoration when it was restored with Centurion N, Giomer and Ketac N100 respectively. Finite element analysis has been used to evaluate the stress distribution.
Results: Alkasite glass ionomer cement & Nanohybrid composite values were comparable to withstand masticatory forces but depicted significantly higher resistance to masticatory load when compared to nano-filled resin-modified glass ionomer cement.
Conclusion: Alkasite glass ionomer cement & Nanohybrid composite are suitable restorative material for class V restorations because of low-stress transfer to the tooth.
Purpose: This in-vitro study evaluated the effect of different thicknesses on load to failure of monolithic zirconia crowns (MZC), produced by computer-aided design/computer-aided manufacturing (CAD/CAM) after the combined effects of thermocycling and compressive load-cycling.
Materials and Methods: An Ivorine molar (#19) was prepared to receive an all- ceramic crown and replicated 60 times using highly filled epoxy resin (Viade Products Inc., Camarillo, California, USA). Sixty MZC crowns- of two different companies BruxZir and Diazir with 3 different thicknesses of 0.5 mm, 1 mm, 1.5 mm, were tested. All crowns were cemented to their dies using resin cement (Rely-X Unicem Clicker) and subjected to the following accelerated artificial aging program: water storage at 37ºC for 5 weeks, thermocycling (5-55ºC) for 8,000 cycles and load-cycling for 250,000 cycles (20 to 270 N). All samples were subsequently loaded in the central fossa area to fracture at a crosshead speed of 1 mm/min with a tungsten carbide ball of 3 mm in an MTS universal testing machine. Data was analysis by the Kruskal-Wallis test, followed by a Mann–Whitney test with Bonferroni correction, p < 0.05.
Results: Crown survival rates after artificial aging was 100%. Regarding the fracture loads there was a statistically significant difference among the three thicknesses of MZC, with a mean fracture loads in Newton (N) of: 0.5 mm- 1119.3 N (373.4 N), 1 mm- 1820.3 N (266.1 N), 1.5 mm- 2071.2 N (136.8 N). However, there were no significant statistical difference between the brands.
Conclusions: The thickness of MZC is a significant factor for the fracture strength of the restoration. Long term clinical studies are necessary before recommending all ceramic MZC for daily practice, especially the 0.5 mm thickness.
