ABSTRACT
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.
ABSTRACT
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