RESUMO
AIM: This study aimed at investigating the effect of adding 5% to 20% by weight aluminium oxide powder (Al2O3) on thermal diffusivity of heat-polymerized acrylic resin. MATERIAL AND METHODS: Twenty five cylindrical test specimens with an embedded thermocouple were used to determine thermal diffusivity over a physiologic temperature range (0 to 70°C). The specimens were divided into five groups (5 specimens/group) which were coded A to E. Group A was the control group (unmodified acrylic resin specimens). The specimens of the remaining four groups were reinforced with 5%, 10%, 15%, and 20% Al2O3 by weight. RESULTS were analysed by using one-way analysis of variance (ANOVA). RESULTS: Test specimens which belonged to Group E showed the highest mean thermal diffusivity value of 10.7mm(2)/sec, followed by D (9.09mm(2)/sec), C (8.49mm(2)/sec), B(8.28mm(2)/sec) and A(6.48mm(2)/sec) groups respectively. Thermal diffusivities of the reinforced acrylic resins were found to be significantly higher than that of the unmodified acrylic resin. Thermal diffusivity was found to increase in proportion to the weight percentage of alumina filler. CONCLUSION: Al2O3 fillers have potential to provide increased thermal diffusivity. Increasing the heat transfer characteristics of the acrylic resin base material could lead to more patient satisfaction.
RESUMO
This article presents a case report of a 20 year old female who was very much dissatisfied with her facial appearance and smile.On examination, it was found that there was a Angles class II division 1 malocclusion and a generalised spacing in the anterior teeth, with a retained, deciduous, left maxillary canine and a malposed 15. On radiographic examination, an impacted 18, 23 was noticed. As the part of the treatment plan, the retained deciduous canine and the impacted permanent canine were extracted and an orthodontic correction of the malocclusion was accomplished. The missing canine was planned to be replaced with a fixed partial denture.The short clinical crown height of the abutment teeth was increased by crown lengthening procedures and the pontic space was contoured to receive a ovate pontic by using diode lasers. The missing tooth was restored by using an all ceramic three unit zirconia bridge. This multi-disciplinary approach improved the smile of the patient and it ultimately enhanced her aesthetics and self confidence.
RESUMO
OBJECTIVE: Musculoskeletal disorders (MSDs) are commonly experienced in dentistry. The objective of this study is to determine the prevalence of ergonomics and MSDs among dental professionals. MATERIALS AND METHODS: A cross-sectional survey was conducted among 170 dentists of different specialties. The questionnaire gathered information regarding demographic details, MSDs, work duration, working status, awareness of ergonomics, etc. Data was analyzed using SPSS version 15.0. Student's t-test and analysis of variance (ANOVA) test was used for comparison in mean scores. Stepwise multiple linear regression analysis was used to assess the independent variables that significantly influenced the variance in the dependent variable (pain). RESULTS: It was found that 73.9% of the participants reported musculoskeletal pain and most common painful sites were neck and back. More than half of the participants, i.e. 232 (59.3%) were aware of correct ergonomic posture regarding dental. Almost percentage of pain increased significantly with increase in age and working time. Among all specialties, prosthodontics were found to have more prevalence of MSDs. CLINICAL SIGNIFICANCE: The appearance of musculoskeletal symptoms among dental professionals was quite common. It suggested that ergonomics should be covered in the educational system to reduce risks to dental practitioners.
