ABSTRACT
Statement of Problem: Despite the numerous positive features of acrylic denture base, there are a number of undeniable associated disadvantages. The properties of denture base have been improved through various interventions including application of different types of filler and coatings
Objectives: This study aimed to evaluate the surface roughness, thickness and coating quality of organic-inorganic coating on the denture base through scanning electron microscopy. Moreover, the colour change was evaluated visually
Materials and Methods: The organic-inorganic hybrid coatings were prepared. Acrylic discs of 10x10 mm were fabricated. The test discs were dipped in the hybrid coating and cured. In order to evaluate the surface roughness and coating thickness, the surface and cross-section of the samples in both coated and control groups were subjected to scanning electron microscopy. The colour change and transparency were visually evaluated with naked eyes. The data were statistically analyzed by student's t test
Results: The hybrid materials perfectly covered all the surfaces of acrylic resin and established proper thickness. The coated group seemed smoother and flatter than the control group; however, the difference was not statistically significant [for all parameters p > 0.05]. It was quite a thin coating and no perceptible colour change was observed
Conclusions: The hybrid coating maintained good binding, caused no noticeable discoloration, and thoroughly covered the acrylic resin surface with uniform delicate thickness. It also slightly improved the acrylic resin surface roughness
ABSTRACT
One of the difficult aspects of designing complete denture prosthesis is the selection of appropriately sized maxillary anterior teeth. The aim of this investigation was to determine if there is any relationship between the intercanthal dimension and mesiodistal width of combined four maxillary anterior teeth. The maxillary anterior teeth were examined in 300 adult subjects. The distance between the median palpebral fissures was measured as the intercanthal distance. The mean width of the two central incisors, the combined widths of the central incisors, the combined width of the four incisors and the combined width of six anterior teeth were determined intra-orally at the widest dimension. T-test and Pearson correlation were used for statistical analysis. The men width of 4 maxillary incisor teeth was 30.8 +/- 1.91 mm and the mean width of 6 anterior maxillary teeth was 46.47 +/- 2.54 mm. Although the Pearson correlation was relatively small, a significant relationship was detected between the intercanthal and four maxillary teeth dimensions in all subjects [P=0.0001]. It was found that biometric ratio of 0.266 and 1.447 could be used to estimate the central incisor width and the combined widths of the six anterior teeth, respectively. The intercanthal distance can be used as preliminary criteria to determine the width of maxillary anterior teeth for edentulous patients