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PURPOSE@#This study aimed to evaluate the effect of incorporating zirconium oxide nanoparticles (nano-ZrO 2 ) in polymethylmethacrylate (PMMA) denture base resin on flexural properties at different material thicknesses. @*MATERIALS AND METHODS@#Heat polymerized acrylic resin specimens (N = 120) were fabricated and divided into 4 groups according to denture base thickness (2.5 mm, 2.0 mm, 1.5 mm, 1.0 mm). Each group was subdivided into 3 subgroups (n = 10) according to nano-ZrO2 concentration (0%, 2.5%, and 5%). Flexural strength and elastic modulus were evaluated using a three-point bending test. One-way ANOVA, Tukey’s post hoc, and two-way ANOVA were used for data analysis (α = .05). Scanning electron microscopy (SEM) was used for fracture surface analysis and nanoparticles distributions. @*RESULTS@# Groups with 0% nano-ZrO2 showed no significant difference in the flexural strength as thickness decreased (P = .153). The addition of nano-zirconia significantly increased the flexural strength (P < .001). The highest value was with 5% nano-ZrO2 and 2 mm-thickness (125.4± 18.3 MPa), followed by 5% nano-ZrO2 and 1.5 mm-thickness (110.3 ± 8.5 MPa). Moreover, the effect of various concentration levels on elastic modulus was statistically significant for 2 mm thickness (P = .001), but the combined effect of thickness and concentration on elastic modulus was insignificant (P = .10). @*CONCLUSION@# Reinforcement of denture base material with nano-ZrO2 significantly increased flexural strength and modulus of elasticity. Reducing material thickness did not decrease flexural strength when nano-ZrO2 was incorporated. In clinical practice, when low thickness of denture base material is indicated, PMMAano-ZrO2 could be used with minimum acceptable thickness of 1.5 mm.
ABSTRACT
PURPOSE@#This study aimed to evaluate the effect of incorporating zirconium oxide nanoparticles (nano-ZrO 2 ) in polymethylmethacrylate (PMMA) denture base resin on flexural properties at different material thicknesses. @*MATERIALS AND METHODS@#Heat polymerized acrylic resin specimens (N = 120) were fabricated and divided into 4 groups according to denture base thickness (2.5 mm, 2.0 mm, 1.5 mm, 1.0 mm). Each group was subdivided into 3 subgroups (n = 10) according to nano-ZrO2 concentration (0%, 2.5%, and 5%). Flexural strength and elastic modulus were evaluated using a three-point bending test. One-way ANOVA, Tukey’s post hoc, and two-way ANOVA were used for data analysis (α = .05). Scanning electron microscopy (SEM) was used for fracture surface analysis and nanoparticles distributions. @*RESULTS@# Groups with 0% nano-ZrO2 showed no significant difference in the flexural strength as thickness decreased (P = .153). The addition of nano-zirconia significantly increased the flexural strength (P < .001). The highest value was with 5% nano-ZrO2 and 2 mm-thickness (125.4± 18.3 MPa), followed by 5% nano-ZrO2 and 1.5 mm-thickness (110.3 ± 8.5 MPa). Moreover, the effect of various concentration levels on elastic modulus was statistically significant for 2 mm thickness (P = .001), but the combined effect of thickness and concentration on elastic modulus was insignificant (P = .10). @*CONCLUSION@# Reinforcement of denture base material with nano-ZrO2 significantly increased flexural strength and modulus of elasticity. Reducing material thickness did not decrease flexural strength when nano-ZrO2 was incorporated. In clinical practice, when low thickness of denture base material is indicated, PMMAano-ZrO2 could be used with minimum acceptable thickness of 1.5 mm.
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Objective: this study was designed to evaluate the perception of students and interns toward research
Materials and Methods: the study was conducted in January 2014. Participants of the study were fourth, fifth, and 6[th] year students and interns. A questionnaire comprised thirteen questions was distributed to evaluate students' and interns' perception about the importance of research in their learning
Results: the results showed that interns and 6th year students were more interested in research as compared to their junior counterparts as they realized the importance of research in their educational growth. This was reflected by the number of interns who completed the questionnaire
Conclusion: dental students realized the importance of research in the education, but it was found that the proportion of students who did research as part of their course was very low. Students should be actively engaged in research, which can be achieved by introducing research as a compulsory component of their course
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Objectives: The study aimed to identify the dental procedures that elicit the highest level of anxiety by various dental procedures and to determine the correlation of anxiety with students' gender and varying perceptions of anxiety across years of dental education
Methods: This cross-sectional study was conducted at Sardar Begum Dental College, Peshawar, Pakistan during June 2014. The Corah's Dental Anxiety Scale [DAS] was distributed to all students. This instrument had 26 items examining the anxiety levels experienced for different dental procedures. Options ranging from 1 to 4 were provided for every item, where 1 represented low anxiety and 4 represented the highest anxiety
Results: The overall response rate was 67.3% [n = 101; 64 females and 37 males]. Among the top five dental procedures eliciting the highest anxiety levels, females were found to be more anxious than males for all procedures [fear of injection/needle, root canal treatment, extraction, and application of cold air] except the need for further treatment. Pre-clinical students [1[st] and 2[nd] year] were found to be more anxious than clinical students [3[rd] and 4[th] year]. Significant differences [p < 0.05] were found for three procedures: rubber dam placement, inability to stop dentist, and impression taking. Clinical students reported high anxiety for the latter, and pre-clinical students reported higher anxiety for the former two procedures
Conclusions: Higher anxiety levels were reported by females and pre-clinical students than their respective counterparts. Educational sessions and graded exposure therapy at an initial stage of dental educational training may decrease the anxiety associated with dental procedures
Subject(s)
Humans , Gender Identity , Cross-Sectional Studies , Fear , Education, Dental , Students, DentalABSTRACT
To evaluate patients' perception regarding treatment and environment in the interns' clinic at a university dentistry clinic. This cross-sectional study was conducted between July 2012 to May 2013 at the College of Dentistry, University of Dammam, Dammam, Kingdom of Saudi Arabia. A self-directed questionnaire was distributed to 220 randomly selected patients, and the response rate was approximately 68%. Patients' were asked regarding dentists' behavior, treatment, and clinical environment along with their demographics, and socioeconomic status. Out of the 220 randomly selected patients, 150 participated in the study. The average age of a respondent was 32.5 years [ +/- 14.5], 89 of the 150 participants were Saudi nationals. Collectively, 86% were satisfied with the doctors' behavior, and approximately 94% responded that the dentist listens to their concerns. Most [83%] were satisfied with the treatment plan provided by the interns. The findings in this study showed that more than 80% of the participants were satisfied with the quality of treatment and clinical environment. The dissatisfaction rate was minimal [13%] and for this reason, it is difficult to establish the factors for patients dissatisfaction.
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To determine the prevalence of caries in the primary and permanent teeth in a Saudi population. This study was conducted at the College of Dentistry, University of Dammam, Dammam, Kingdom of Saudi Arabia. In June 2010, a literature search was started and found all studies conducted in Saudi Arabia on dental caries from 1999 to 2008. Sixty articles were found on PubMed, which had been published during the considered time period. Sixteen studies were passed through inclusion criteria and included in analysis. A 2 to 12-year-old Saudi population was included to determine the prevalence of caries in primary teeth, and for permanent teeth, the age range was 6-18 years. The prevalence of caries in primary and permanent teeth were analyzed separately. Forest plot and Chi-square test revealed considerable heterogeneity. A random effect model was used to find caries prevalence in primary and permanent teeth. The mean decayed, missing and filled teeth [dmft] was 5.38 [95% CI: 4.314 - 6.436], and in the permanent teeth the DMFT was 3.34 [95% CI: 1.97 - 4.75]. Publication bias diagnostics suggested possible overestimation of caries prevalence in permanent teeth but not in primary teeth. The results in this study present a high decayed, missing, and filled teeth score in the adult and young population of Saudi Arabia, however, more published data is required as the results obtained from this meta analysis may not give a true picture, and reality may be worse