The cobalt-chromium (CoCr) partial denture has been made for a long period. It respects biomechanical principles, providing harmony between mechanical and biological activities. The fundamental principles of biomechanics applied in the manufacture of steel structure are: retention, reciprocity, attachment and stability. To get the proper planning, we need to assess the dental support system, with its qualitative and quantitative values. But conventional dentures has a inherent problem which is the metallic elements apparent and in some cases the stiffness of the component support elements that generates stress.

The Thermoplastic partial dentures increase aesthetics in replacement of metal structures in oral rehabilitation. So many treatments are being done in everyday practice without a defined concept on various aspects of its construction and oral applicability.

This trial aims to assess the basic parameters of both dentures in: nutrition, speech therapy, chewing force, chewing efficiency and quality of life.

60 years old or older patients who require removable prosthesis. These will be randomly selected for the fabrication and installation of removable partial dentures (Gold Standard - control group - CoCr partial denture) and thermoplastic partial denture(experimental group).

Before beginning the work, selected patients will make some preliminary tests such as controlling the individual condition, they are:

• three questionnaires:
• instrument for assessing quality of life related to oral health, GOHAI - General Oral Health Assessment Index of Atchinson & Dolan
• instrument for assessing the social and economic profile of ABEP (Brazilian Association of Research Companies) CCEB 2011;
• Instrument for assessing cognitive condition MINI-MENTAL;
• Speech evaluation
• Nutritional assessment;
• Evaluation of masticatory efficiency and
• Chewing strength. After preliminary assessments patients will be subjected to treatments for manufacture of partial dentures. After the installation (end of the technical construction of the dentures) and the adjustments appointment the tests will be repeated and in successive control periods of 3 months, 6 months, 12 months, 18 months and 24 months respectively, when the tests will do again now to see if there was a change in the initial condition.

Inclusion Criteria:

60 years old or older patient with partial edentulous jaws with indication of removable partial denture

Exclusion Criteria:

patient younger than 60 years patient with edentulous mouth