No abstract

Finding the most suitable position for artificial anterior teeth in the absence of pre-extraction records presents a new challenge with every denture and has resulted in a variety of measurements. It encompasses the knowledge of anatomy and physiology of oral tissue. In this study, the relation between anatomical landmarks the tips of the maxillary canines, edge of central incisor and center of incisive papilla was evaluated and compared with respect to arch form in Indian population. Arch forms were accessed by their morphological description as square, tapering or ovoid arch. Measurements on the casts were recorded for incisive papilla and maxillary central incisor distance, by digital vernier caliper and photographic technique was used to record the relation between tips of the canine and the centre of the incisive papilla. The mean distance between edge of central incisor to center of incisive papilla for square arch, oval arch and tapered arch was found as 9.667, 9.991 and 10.912 mm respectively. When all the 300 casts were taken together, it indicated that 51.3 % of intercanine lines passed through the center, 18.1 % of inter canine lines passed posterior and 30.6 % of the intercanine lines passed anterior to the center of incisive papilla. χ(2) (Chi square) values concluded they differ significantly and significant number of intercanine lines crossed through the center of the incisive papilla irrespective of the arch form.

Dimensional accuracy when making impressions is crucial to the quality of fixed prosthodontic treatment, and the impression technique is a critical factor affecting this accuracy. The purpose of this study was to compare the dimensional accuracy of one-step putty wash and twostep putty wash impression techniques using commercially available addition silicone impression material. The accuracy was assessed by measuring intraabutment and interabutment dimensions on stone dies poured from impressions of the master model, by using Toolmaker's microscope.

The purpose of the study was to compare the marginal accuracy of Ni-Cr copings made by four different pattern forming methods, using inlay casting wax and pattern resin in the conventional manner, inlay wax patterns by CAD & milling and resin patterns made by a 3 dimensional printing (3DP) technology a total of 40 test samples of Ni-Cr cast copings were made out of 10 patterns of each group using inlay casting wax, pattern resin, inlay wax by CAD and milling and from pattern resin by 3D printing technology. Each cast coping was seated on the stainless steel die and was evaluated for both vertical and horizontal marginal gaps using a translating tool makers microscope. The vertical marginal gap data was analyzed by use of Kruskal Wallis Test followed by Mann Whitney U Test and the horizontal marginal gap data was analyzed by using ANOVA followed by Tukey honestly significantly different (HSD) tests. 3D printed resin pattern copings showed better results of marginal adaptability. marginal fit of the Ni-Cr cast copings fabricated from the patterns prepared from inlay casting wax, pattern resin, CAD milling and 3 dimensional printing (3DP) technology were in the clinically acceptable range for longevity of restorations.