Polymethyl methacrylate have been used since 1937 as a gold standard for a denture base material because of its several advantages as; good esthetics, adequate strength, easy repair and simple processing techniques. As any material it has some problems as polymerization shrinkage, low impact and flexural properties and low fatigue resistance2. So polyamide was introduced into dentistry to be used as a denture base material in order to solve these problems. Polyamide denture base materials have some superior properties than PMMA as; High impact & flexural strength, excellent esthetics and less release of residual monomers4. Although being an advantage from the point of patient satisfaction, flexural property considered to be a contraindication for a denture base material.

The invistigators' trial is done in order to improve rigidity of a polyamide material as well as to improve oral health related quality of life in comparison to heat cured polymethyl methacrylate.

Inclusion Criteria:

- i. Male or female patient with age range (45-55) and in good medical condition ii. All patients have skeletal Angle's class I maxillo-mandibular relationship and have sufficient inter-arch distance.

iii. Free from any systemic or neuromuscular disorder that might affect chewing efficiency of masticatory muscles.

iv. Free from any tempro-mandibular joint disorder. v. The patients have good oral hygiene.

Exclusion Criteria:

- i. Patients having hormonal disorders as diabetes, thyroid or parathyroid hormonal diseases were not included.

ii. Patient with xerostomia or excessive salivation. iii. Patient with abnormal tongue behavior and/or size. iv. No intraoral soft and hard tissue pathosis