MATERIALS AND METHODS: The HVGICs evaluated were Zirconomer [ZR] (Shofu), Equia Forte [EQ] (GC) and Riva [RV] (SDI). Sixty specimens (12mm x 2mm x 2mm) of each material were fabricated using customized Teflon molds. After initial set, the specimens were removed from their molds, finished, measured and randomly divided into 3 groups of 20. Half the specimens in each group were left uncoated while the remaining half was covered with the respective manufacturers' resin coating. The specimens were subsequently conditioned in distilled water, artificial saliva or citric acid at 37°C for 7 days. The uncoated and coated specimens (n=10) were then subjected to dynamic mechanical testing in flexure mode at 37°C with a frequency of 0.1 to 10Hz. Storage modulus, loss modulus and loss tangent data were subjected to normality testing and statistical analysis using one-way ANOVA/Scheffe's post-hoc test and Ttest at significance level p<0.05.
RESULTS: Mean storage modulus ranged from 1.39 ± 0.36 to 10.80 ± 0.86 GPa while mean loss modulus varied from 0.13 ± 0.03 to 0.70 ± 0.14 GPa after conditioning in the different mediums. Values for loss tangent ranged from 39.4 ± 7.75 to 213.2 ± 20.11 (x10 -3 ). Significant differences in visco-elastic properties were observed between mediums and materials. When conditioned in distilled water and artificial saliva,storage modulus was significantly improved when ZR, EQ and RV were uncoated. Significantly higher values were, however, observed with resin coating when the materials were exposed to citric acid.
CONCLUSION: The visco-elastic properties of HVGICs were influenced by both resin coating and chemical environment.
OBJECTIVE: This study aims to determine the prevalence of musculoskeletal disorders among dentists, explore the risk factors and identify the ergonomic preventive measures for dental professionals.
METHODS: Articles published between 2008-2020 were searched in scientific databases (MEDLINE, PubMed, Scopus and Cochrane Library). The Critical Appraisal Skills Programme Systematic Review Checklist was used to assess the quality of the studies.
RESULTS: Eighteen studies were found to be suitable in the final review. Relevant data was extracted and summarized from the included studies. The annual prevalence of musculoskeletal disorders in any body site ranged between 68% and 100%. The most predominant regions for musculoskeletal disorders among dental professionals were identified to be the lower back (29% to 94.6%), shoulder (25% to 92.7%), and neck (26% to 92%). The most frequently reported risk factors of MSDs were the individual characteristic female gender (57.1%), followed by awkward working postures (50%), long working experience (50%) and being dental specialists (42.9%). Several preventive measures were identified as the most effective ways in preventing MSDs, the use of magnification (40%) and regular physical activity (40%).
CONCLUSIONS: This review reported a high prevalence of musculoskeletal disorders (MSD) among dentists. It critically updates and adds the latest evidence on occupational ergonomics among dentists.
PURPOSE: The purpose of this study was to develop and validate a novel instrument, termed the questionnaire on perceived prosthodontic treatment needs (PPTN), that assesses perceived prosthodontic treatment needs in adults.
MATERIAL AND METHODS: The PPTN was developed following a literature review, consultation with healthcare workers, and patient interviews. It included 15 questions and a self-rated need for prosthodontic treatment, categorized on a Likert scale. A cross-sectional descriptive study was completed on 193 dental patients seeking or receiving prosthodontic treatment.
RESULTS: Three perceived prosthodontic treatment need factors were identified (psychosocial impact, esthetic concern, and function) by using exploratory factor analysis. A higher PPTN score indicated greater perceived prosthodontic treatment needs. The identified factors represent 67.8% of the variance with eigenvalues of >1. The PPTN had a high degree of internal consistency and reliability, as the final questionnaire received a Cronbach alpha of 0.75 and an intraclass coefficient of 0.75 with a 95% confidence interval of 0.68 to 0.80 (F(192, 576)=3.94, P
METHODS: A total of 150 undergraduate students (33 males and 117 females) aged 19 to 24 years at Universiti Kebangsaan Malaysia participated in this study. The Basic Erosive Wear Examination was used to assess the occurrence of tooth erosion. Information regarding dental hygiene practices, usual dietary habits, and consumption of acidic foods and drinks was obtained through a structured questionnaire.
RESULTS: In all, 68% of subjects had tooth erosion. Subjects who reported having received information about healthy eating were less likely to have tooth erosion (χ(2) [1, N = 150] = 7.328, P = 0.007). The frequencies of milk (OR = 0.29, 95% CI = 0.13-0.67) and tea/coffee (adjusted OR = 0.42, 95% CI = 0.19-0.95) consumption were negatively associated with tooth erosion. Dental hygiene practice, the frequency and amount of acidic food and drink intake, and body mass index classification were not significantly associated with the risk of tooth erosion (P > 0.05).
CONCLUSION: A high prevalence of tooth erosion was observed among this group of students. Preventive measures, such as dietary advice and increased consumption of milk at a younger age, may reduce the occurrence of tooth erosion among this age group.