Fabrication of titanium removable dental prosthesis frameworks with a 2-step investment coating method.
BACKGROUND
Although pure titanium is known to have good biocompatibility, a titanium alloy with better strength is needed for fabricating clinically acceptable, partial removable dental prosthesis (RDP) frameworks.


OBJECTIVE
The mechanical properties of an experimental Ti-5Al-5Cu alloy cast with a 2-step investment technique were examined for RDP framework applications.


METHODS
Patterns for tests for various properties and denture frameworks for a preliminary trial casting were invested with a 2-step coating method using 2 types of mold materials: a less reactive spinel compound (Al(2)O(3)·MgO) and a less expensive SiO(2)-based material. The yield and tensile strength (n=5), modulus of elasticity (n=5), elongation (n=5), and hardness (n=8) of the cast Ti-5Al-5Cu alloy were determined. The external appearance and internal porosities of the preliminary trial castings of denture frameworks (n=2) were examined with a conventional dental radiographic unit. Cast Ti-6Al-4V alloy and commercially pure titanium (CP Ti) were used as controls. The data for the mechanical properties were statistically analyzed with 1-way ANOVA (α=.05).


RESULTS
The yield strength of the cast Ti-5Al-5Cu alloy was 851 MPa and the hardness was 356 HV. These properties were comparable to those of the cast Ti-6Al-4V and were higher than those of CP Ti (P<.05). One of the acrylic resin-retention areas of the Ti-5Al-5Cu frameworks was found to have been incompletely cast.


CONCLUSIONS
The cast biocompatible experimental Ti-5Al-5Cu alloy exhibited high strength when cast with a 2-step coating method. With a dedicated study to determine the effect of sprue design on the quality of castings, biocompatible Ti-5Al-5Cu RDP frameworks for a clinical trial can be produced.
Department of Restorative Science, Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, Texas 75246,USA.
Mari
M
Koike
Susan K
SK
Hummel
John D
JD
Ball
Toru
T
Okabe
D000497:Alloys / Q000737:chemistry*; D000535:Aluminum / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry*; D003734:Dental Casting Investment / Q000737:chemistry*; D003735:Dental Casting Technique; D003764:Dental Materials / Q000737:chemistry; D003779:Denture Design; D003832:Denture, Partial, Removable; D055119:Elastic Modulus; D004548:Elasticity; D006244:Hardness; D006801:Humans; D008277:Magnesium Oxide / Q000737:chemistry; D008422:Materials Testing; D016062:Porosity; D012828:Silicones / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D014025:Titanium / Q000737:chemistry*
D000497:Alloys; D003722:Dental Alloys; D003734:Dental Casting Investment; D003764:Dental Materials; D012828:Silicones; C576662:Ti-5Al-5Cu alloy; C111130:spinell; C031462:titanium alloy (TiAl6V4); D008277:Magnesium Oxide; D003300:Copper; D000535:Aluminum; D014025:Titanium; D000537:Aluminum Oxide