The aim of the present study was to evaluate the Knoop hardness of high viscous glass ionomer cement (GIC) Ketac Molar Easy Mix (3M ESPE, Saint Paul, USA) submitted to different types of compounds for surface protection. Sixty specimens of GIC were made in PVC molds with 7.5 mm diameter and 2.5 mm thickness. Divided in 6 groups: G1, Control (no protection); G2, Cavitine (Copal varnish); G3, Magic bond (Adhesive); G4, Adper Single Bond 2 (Single bottle adhesive); G5, Solid Petroleum Jelly; G6, Nail Varnish. The surface protection was applied after initial setting reaction. The specimens were immersed in deionized water, at 37 degrees C, for 24 h. The surfaces were polished in a rotation machine (Aropol 2V). The hardness test was accomplished in a Digital Microhardness tester HVS-100. In each specimen five indentations were done and repeated after 30 days and 4 months, under the same conditions. The results were submitted to Two-way ANOVA and Tukey Test. The only material that differed from the control group was the nail varnish (p < 0.001), with the other materials showing no significant difference from the control group. It was concluded that the best material for surface protection of GIC was the nail varnish, but because of possible harmful effects, petroleum jelly could be a better option.
INTRODUCTION: This study aims to determine the shape and dimension of dental arches from a
lingual perspective, and determine shape and size of a straight archwire used for
lingual Orthodontics. METHODS: The study sample comprised 70 Caucasian Brazilian individuals with normal
occlusion and at least four of Andrew's six keys. Maxillary and mandibular dental
casts were digitized (3D) and the images were analyzed by Delcam Power SHAPET 2010
software. Landmarks on the lingual surface of teeth were selected and 14
measurements were calculated to determine the shape and size of dental arches.
RESULTS: Shapiro-Wilk test determined small arch shape by means of 25th
percentile (P25%) - an average percentile for the medium arch; and a large one
determined by means of 75th percentile (P75%). T-test revealed
differences between males and females in the size of 12 dental arches. CONCLUSION: The straight-wire arch shape used in the lingual straight wire technique is a
parabolic-shaped arch, slightly flattened on its anterior portion. Due to
similarity among dental arch sizes shown by males and females, a more simplified
diagram chart was designed.
Objective: To analyze the variations of hard palate volume in adults with normal occlusion and different facial types and patterns, by using a three-dimensional analysis on digital casts. Methods: The dental casts of 70 Caucasian adults (28 men, 42 women), mean age of 16.4 years (SD 1.3 years), were scanned by using a tridimensional scanner (Delcam PowerSHAPE™, 2010, Birmingham, UK). Close points were selected in the gingival and cervical regions on the lingual surface of the maxillary teeth, to analyze palatal morphology. The facial patterns and types, and the measurements (width, length, height, volume) of the space on the hard palate were compared using analysis of covariance (ANCOVA), with age as the covariate, and sex as the independent variable. The significance level of 5% (p < 0.05) was adopted. Results: This study showed that the measurements of the width and length were similar among the mesofacial, dolichofacial and brachyfacial facial types, although the height and volume of the space on the hard palate were slightly smaller in dolichofacial individuals, and both Pattern I and Pattern II individuals showed no significant changes for the four measurements. The mean values among facial patterns were: Pattern I - width 38.31±2.59 mm; length 37.44±2.42 mm; height 17.03±2.42 mm and volume 10.52±1.72 mm3; Pattern II - width 37.48±2.44 mm; length 37.48±2.44 mm; height 16.79±2.42 mm and volume 10.41±1.65 mm3 (p>0.05 for all variables). Conclusion: There were no significant differences for the facial patterns and facial types of the individuals compared in the analyzed sample.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.