Tri-dimensional measurements to evaluate dimensional alterations in gypsum patterns for complete dentures

Abstract

The use of machines to measure specifics points in the patterns, these points transference to a tri-dimensional design program and the areas math calculation, by the solids produced in that program are an efficient alternative to verify and after compare the dimensional variations that occurs in gypsum patterns, related of the moulding materials. The use of this technology was fundamental for determinating dimensional variation's accuracy, that in most case are too acute and hard to be determinated and compared. The present paper proved how important is the use of method to get tri-dimensional points, to obtain the respectives digital solids and areas and volumes calculation by finite element method. These concepts are important, since they strongly contribute for the result accuracy about dimensional variation, as mathematic treatment was made in three dimensions (breadth, length and height) on the pattern in study.

Dimensional changes occurred in cast for complete dentures evaluated by tri-dimensional measurements

“…Seven screws were set in the metallic die to be referential points of linear measurements, to obtain areas and volumes that would be calculated by a tridimensional software. 10 The tri-dimensional coordinate measurements were made in both stone casts and aluminum pattern die. 10 Tri-dimensional measurement equipment (Mitutoyo, model BlN 710; Tokyo, Japan) fitted out with measurement head Renishaw PH9 and searcher TP 200 with 1 mm diameter was used to accomplish the measurements.…”

“…10 The tri-dimensional coordinate measurements were made in both stone casts and aluminum pattern die. 10 Tri-dimensional measurement equipment (Mitutoyo, model BlN 710; Tokyo, Japan) fitted out with measurement head Renishaw PH9 and searcher TP 200 with 1 mm diameter was used to accomplish the measurements. The equipment associated with a CAD (Computer Aided Design) system permitted the determination of X, Y, Z coordinates or Cartesian axes that is used to get all the geometry dimensions.…”

“…Manly methods are used to evaluate the dimensional alterations that happen in impressions and stone casts, as profile projector,1,6 perphilometer,3 confronter optical microscope,1 MMTs machines, 4,7-9 and mesh of finite elements. 10,12 The purpose of this study was to verify the dimensional changes occurred in dental stone casts obtained from impression for complete denture procedure, by means of tri-dimensional design obtained from mathematical calculation.…”