Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.

1. DEFINITION OF OVERLAY DENTURE:
A removable partial and complete denture that covers and rests on one or
more remaining natural teeth , roots, and / or dental implants. A prosthesis that
covers and is partially supported by natural teeth, roots, and /or dental implants.
Such overlay partial denture has the following advantages:
 Increase support and stability.
 Decrease in alveolar bone resorption
 Patients proprioception is maintained
 Improvement in the crown-root ratio of the abutment teeth
 Improvement in masticatory efficiency better retention.
DISADVANTAGES:
 Periodontal disease
 Dental caries
 Endodontic failure
 Mechanical failure.
Drawbacks of titanium castings:
1. Bessing et al 1992 showed the irregular surface quality of Ti casting
because of high chemical reactivity of titanium with investment at elevated
temperatures .
2. Hero et al 1993 suggested that the internal porosity rate of ti casting was
high because of increased solubility of gases like H O N in molten metal.

2. 3. Robert stein et al 1995 suggested that the sprue designs for the Ti castings
are to be modified because of low density of titanium .Othewise may
produce different castability and porosity effects for low density metals .
4. The high reactivity of titanium with O necessitates special low temperature
burnout procedure ,soaked temperature ,mold material and equipment
having inert medium like argon or helium during melting and casting.
Merits of Titanium for Dental Use:
1. Low density 4.5gm/cm3 in comparision with Co-Cr (8.9gm/cm3)
gold(19.3gm/cm3)
2. Superior mechanical properties .
 High strength
 Stiffness
 Ductility
 Execellent corrosion resistance
 Low modulus of elasticity cp Ti (103.4 Mpa)
3 Excellent biocompatibility
4 Economical.
All these merits documented made the researchers to overcome the
drawbacks mentioned earlier. Therefore titanium has not remained the metal for
the future dental castings but the metal for the present as well as future.