Effect of different palatal vault shapes on the dimensional stability of glass fiber-reinforced heat-polymerized acrylic resin denture base material.

OBJECTIVE: The aim of this study was to determine the effect of different palatal vault shapes on the dimensional stability of a glass fiber reinforced heat polymerized acrylic resin denture base material. METHODS: Three edentulous maxilla with shallow, deep and medium shaped palatal vaults were selected and elastomeric impressions were obtained. A maxillary cast with four reference points (A, B, C, and D) was prepared to serve as control. Point (A) was marked in the anterior midline of the edentulous ridge in the incisive papillary region, points (B) and (C) were marked in the right and left posterior midlines of the edentulous ridge in the second molar regions, and point (D) was marked in the posterior palatal midline near the fovea palatina media (Figure 2). To determine linear dimensional changes, distances between four reference points (A-B, A-C, A-D and B-C) were initially measured with a metal gauge accurate within 0.1 mm under a binocular stereo light microscope and data (mm) were recorded. RESULTS: No significant difference of interfacial distance was found in sagittal and frontal sections measured 24 h after polymerization and after 30 days of water storage in any of experimental groups (P>.05). Significant difference of linear dimension were found in all experimental groups (P<.01) between measurements made 24 h after polymerization of specimens and 30 days after water storage. CONCLUSION: Palatal vault shape and fiber impregnation into the acrylic resin bases did not affect the magnitude of interfacial gaps between the bases and the stone cast surfaces.

The three-dimensional finite element analysis of fixed bridge restoration supported by the combination of teeth and osseointegrated implants.

This study investigated the designs of osseointegrated prostheses in cases of free-end partial edentulism using comparative stress interpreted with the three-dimensional finite element method. Three free-end fixed osseointegrated prostheses models with various connection designs (i.e., rigidly connected to an abutment tooth and an implant, rigidly connected to an implant and two abutment teeth, and rigidly connected to an implant and three abutment teeth) were studied. The stress values of the three models loaded with vertical, buccolingual, and linguobuccal directions at 30 degrees angled to vertical axis forces were analyzed. When the fixed partial denture was connected to the three natural abutment teeth and an implant, the lowest levels of stress in the bone were noted.