Comparing the stresses transmitted by CAD/CAM milled zirconia teeth vs porcelain teeth in complete denture to the underlying structure (In vitro study)

Abstract

The objective of this in vitro study was to evaluate the strain values under two complete denture acrylic bases with two different denture teeth materials; porcelain denture teeth and CAD/CAM milled zirconia teeth, using strain gauge. The acrylic model was duplicated from mandibular edentulous stone model to be used in the stress analysis. Six experimental complete dentures were constructed on the stone casts. They were divided into two groups (three for each group);  Group I used porcelain denture teeth that are mechanically attached to heat cured acrylic denture base.  Group II used CAD/CAM milled zirconia crowns that are mechanically attached to heat cured acrylic denture base. Strain gauge analysis: Strain gauges were bonded to the crest of the ridge; one at the center of mastication (contact between second premolar and first molar) and the other between canine and first premolar on the crest of the ridge on each side of each model. After processing the complete dentures of both groups, they were placed on the acrylic cast, then loaded with ascending load of 0 to 100 N unilateral vertical and bilateral vertical and unilateral oblique loadings.