Measurement of surface roughness of tow different material of denture base to find out which material is more hygienic by decreasing the amount of bacterial accumulation.

Using a denture base material as a standard value which is the rapid heat cured acrylic resin and compare it with a new material which is a conventional acrylic resin with addition of titanium dioxide nano particles in surface roughness and measuring it by a device called stylus profilometer this will be done on 20 patients this trial will take about 6 months.

Inclusion Criteria:

1. Completely edentulous maxillary arch and fully dentate mandibular arch with adequate interarch space.
2. The edentulous ridges should be covered by firm healthy mucosa.
3. Angle class I maxillomandibular relationship
4. Healthy and co-operative patients

Exclusion Criteria:

1. Patients with bad habits as severe clenching or bruxism, drug or alcohol addiction, moderate or heavy smoking (greater than 10 cigarettes/day).
2. Previous history of radiotherapy or chemotherapy.
3. Any skeletal problem dictates surgical intervention