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ABSTRACT: Background: One of the important concepts in aesthetic dentistry is "the principle of gradation," where each tooth appears proportionally narrower than its mesial neighbor as the eye moves laterally from the midline. Various mathematical and physiological theories determine the widths of maxillary anterior teeth. Objectives: The study aims to evaluate the prevalence of the golden percentage, the recurring esthetic dental (RED) proportion, and the newly proposed Tarulatha-Ruchi (TR) proportion among dental students from Gujarat state. Materials and Methods: A total of 100 Gujarati students with aesthetically pleasing smiles, ages 18–25 years, were selected. Standard frontal-view photographs were taken with a DSLR camera, displaying maxillary anterior teeth and gingiva in centric occlusion. Adobe Photoshop CS6 was used to measure tooth widths, and the values were analyzed statistically. Results: The exact golden percentage was not followed in any subjects. The percentages for the maxillary central incisor, lateral incisor, and canine were 22%, 16%, and 12%, respectively. The RED proportion did not exist, increasing distally from 69% to 78.5%. For the TR proportion, central incisors did not follow the suggested quotient of 0.3; a quotient of 0.4 for the lateral incisor was present in 99% of subjects; a quotient of 0.3 for the canine was present in 25% of subjects; and a suggested quotient of 0.6 for the combined width of the central and lateral incisors was present in none of the subjects. Conclusion: The golden percentage and TR proportion can be applied if adjusted. RED did not exist among participants. A proportional constant of 0.4 for the lateral incisor by TR proportion can be used to build a missing or peg-shaped lateral incisor. [ABSTRACT FROM AUTHOR]

ABSTRACT: Background: Direct composite restorations face abrupt temperature changes, varying pH, and surface deterioration in the oral environment. Atomic force microscopy (AFM) provides visual and numerical data on surface roughness. Aim: This study evaluates and compares the surface roughness of composite restorative materials after simulating oral conditions. Materials and Methods: Three composite groups (n = 16 each) were tested. Group A: Microhybrid, Group B: Nanofilled, and Group C: Nanohybrid. Each group was divided into four subgroups (n = 4 each): distilled water (control), black coffee, Coca-Cola, and Red Bull. After thermocycling and immersion, surface roughness was measured using AFM. Results: Nanocomposites with uniform monomodal fillers showed the least surface disintegration and superior properties. Conclusion: Resin chemistry, including filler size and matrix composition, is crucial for composite properties and performance under function. [ABSTRACT FROM AUTHOR]

Aim: To assess the canal transportation and centering ability in the mandibular first molars' curved mesiobuccal canals after instrumentation with file systems XP endo Shaper, self-adjusting File (SAF), Hyflex EDM, Pro Taper NEXT, WaveOne Gold, and K files with the help of Cone-Beam Computed Tomography (CBCT). Materials and Methods: Ninety recently extracted mandibular first molars with mesiobuccal roots that had a 25-30 degree canal curvature were assessed. Following preoperative CBCT scans, teeth were allocated randomly to six experimental groups of fifteen. After preparation with XP endo Shaper, SAF, Hyflex EDM, Pro Taper Next, WaveOne Gold, and K files, post-instrumentation scans were taken using same parameters as pre operative scans. At 3 mm, 6 mm, and 9 mm from the apex, samples were assessed for canal transportation and centering ratio. Results: Apical transportation was least for XP endo Shaper as compared to other groups except SAF and the results were statistically significant. K file showed the highest apical transportation toward the lateral wall of the root canal. XP endo Shaper was better in maintaining centering ability of middle and apical third of canal and SAF was better in maintaining centering ability of coronal third. Conclusion: In root canal preparation, least apical transportation and better centering ability with XP endo Shaper than other file systems compared. K file showed the highest transportation. [ABSTRACT FROM AUTHOR]