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Aim:The purpose of this study was to comparatively evaluate the validity of Golden Proportion, Recurring Esthetic Dental (RED) proportion and Golden Percentage in maxillary anterior teeth in population of Himachal Pradesh.Methods and Materials:Dentulous stone casts of maxillary arch were made of the subjects who met the inclusion criteria. Conditions for inclusion criteria included that the individuals:1) should be of Himachaliorigin with agreeable smiles 2) have well aligned anterior dentition 3) should be between age group of 20-40 years Total of 200 students representing Himachal Pradesh population were included. Measurements were done for the spaces in the grids using the digital caliper. Results:1)The Golden Proportion ratio of 1.3 and 1.4 were more commonly observed in 27.5% and 40% respectively than 1.618 which was observed in 5.5% under study of the population. 2)A Paired sample t-test showed there was no significant gender based difference in Lateral/Central incisor Red Proportion.(P-value>0.05) except for the Canine/Lateral Red Proportion. (P-value<0.05). 3)The Golden Percentage for males in central and lateral incisors and canine was 22.48%, 15.96% and 11.08% respectively. The mean value for females in central and lateral incisors and canine was 22.72%, 16.25% and 10.97% respectively. Conclusions:Golden percentage could be used for aesthetic correction and was found to be more applicable in the population included in this study. Golden percentage could be used for aesthetic correction and are more applicable to natural dentition in the population of Himachal Pradesh.
RESUMO
Purpose: The purpose of the study was to evaluate the effect of titanium dioxide and zirconia nanoparticles on transverse strength of heat cure PMMA resin routinely used for complete denture fabrication.Methods: One hundred samples of PMMA resin were made and divided into five groups (20 samples for each group). The test specimens were divided into five groups depending on the concentration of reinforcing nanoparticles as Group 1,2,3,4 and 5; Group 1: PMMA unreinforced (control group), Group 2: PMMA reinforced with 2.5% nanozirconia, Group 3: PMMA reinforced with 5% nanozirconia, Group 4: PMMA reinforced with 2.5% titanium dioxide nanoparticles, and Original ResearchArticle Group 5: PMMA reinforced with 5% titanium dioxide nanoparticles. Universal testing machine was used to conduct a three-point bending test and evaluate the transverse strength of samples. Comparison of mean transverse strength for various groups was carried out by employing one‑way analysis of variance and Bonferroni post hoc tests.Results:The highest and lowest mean transverse strength were observed in Group 3 and 1, respectively. Bonferroni post hoc test showed increase in transverse strength after reinforcement to be statistically significant between all the groups (P = .05) except between the samples of group G1 and G5 and G2 and G3.Conclusion: Addition of nanoparticles in all concentrations significantly increased transverse strength of heat cure PMMA resin as compared to control group. The best result was obtained after adding 5% of nanozirconia particles to the conventional heat polymerized acrylic resin
RESUMO
Purpose: The purpose of the study was tocompare measurements of maxillary occlusal cant obtained through facebow transfer and through lateral cephalogram.Method:40 subjects were included in this study according to inclusion and exclusion criteria and divided into two groups: dentulous and edentulous. For edentulous subjects, all the steps of complete denture fabrication were carried out and finished dentures weredelivered. Alginate impressions were now made for all the subjects (with complete denture worn in edentulous cases) for both upper and lower arches. The study was conducted in two parts. Facebow transfer was done next and casts were mounted. In first partof the study, sagittal inclination was measured after facebow transfer. After mounting of the casts, four points were marked to measure the inclination of the occlusal plane. In second part, cephalometric evaluation of occlusal plane and Frankfurt horizontal plane was carried out. Angle between Frankfurt horizontal plane and the occlusal plane was maxillary occlusal cant. which was evaluated by tracing.Paired t test was used to compare mean facebow values and lateral ceph values in edentulous subjects. Intergroup comparison between lateral ceph and mean facebow values between dentulous and edentulous subjects was evaluated using independent t test.Results:Facebow measurements gave comparatively higher values in both dentulous and edentulous patients and are subjected to less variation as compared to the lateral cephalogram values p<0.0001.Conclusion:The occlusal plane angle of lateral cephalogram was found to be significantly different from angle obtained through facebow transfe
RESUMO
This study investigated the color stability of reline resin after two methods of disinfection i.e microwave disinfection and chemical disinfection. A stainless steel moldwith a breakaway compartment (10 mm in diameter by 0.7 mm thickness) was made to fabricate specimens of various resins. Each material was mixed according to manufacturer’s instructions and applied into the mold. Prior to color stability testing, specimenswere cleaned in distilled water for 20 minutes to kill any microorganisms that may had contaminated the discs during fabrication. And then specimens were immersed in Sodium Perborate Monohydrate 200 ml of solution for 15 days and microwaved for 15 days sothat it is comparable to chemical disinfection soaking. The color stability of each specimen was measured again using spectrophotometer and values were obtained. The data of ∆E, ∆L, ∆b, ∆a were analysed by 2 way repeated measures ANOVAs test. Significant statistic changes in color parameters ∆L, ∆a, ∆b of the reline resin DPI, Ufi Gel Hard And Kooliner were observed when dentures were disinfected by Sodium Perborate Monohydrate 2% solutions. The color stability of the reline resin was influenced by time, regardless of disinfection or non disinfection. This can be attributed to bleaching (whitening) effect of reline material. Discoloration Original Research Article of resin based materials may be caused by intrinsic or extrinsic factors. Intrinsic factors are related to internal alterations in material resulting from physicochemical reactions or residual monomer oxidation with time. Thus the initiator, quantity and type of monomer and the polymerisation efficiency can affect the color stability of resin based materials. The color stability deviation value ∆E significantly increased to maximum for chemical disinfectant, least for Control group and intermediate for microwaved group. Ufi Gel showed the highest deviation ∆E and Control Group showed the lowest deviation according to results