629COMPARATIVE INVITRO EVALUATION OF SURFACE ROUGHNESS OF A POLYAMIDE DENTURE BASE MATERIAL IN COMPARISON WITH COMPRESSION MOLDED HEAT CURE ACRYLIC DENTURE BASE RESINBackground : One of the modes of treatment for replacing missing teeth is partial or complete dentures. Denture base act as an intermediary between the teeth and the jaw. Surface roughness of denture base material is an important for longevity and superior clinical performance of the prosthesis. The surface roughness of a material used for removable prostheses is of importance since it affects, directly or indirectly, retention, staining resistance, plaque accumulation, oral tissue health, and patient comfort. Objective/purpose : The aim of this study was to evaluate and compare surface roughness of compression molded heat cure acrylic denture base resin and polyamide (Nylon) denture base material. Materials and method: Two denture base materials lucitone 199 (compression molded heat cure acrylic denture base resin) and lucitone FRS (polyamide (nylon) denture base material) were used for evaluating and comparing surface roughness. Metal dies of dimensions 65mm x 10mm x 3mm were fabricated which were invested to prepare heat cure acrylic denture base resin specimens by compression moulding technique and, injection mouding technique was used to make specimens of polyamide (lucitone FRS) specimens under strict quality control. Thus total 20 specimens were fabricated, with 10 specimens of each type of denture base material. These specimens were stored in artificial saliva at 37oC in an incubator for 7 days. Surface roughness values were measured using a profilometer. Statistical analysis of the data was done using student t- test. Result: Lucitone 199 denture base resin showed mean surface roughness value of 0.050 µm and a standard deviation of 0.0082 whereas Lucitone FRS denture base material showed mean surface roughness value of 0.197 µm and a standard deviation of 0.016. and this difference was statistically significant (p < 0.05).Conclusion : Within the limitations of the study it was concluded that Polyamide denture base material (Lucitone FRS) showed higher surface roughness when compared to compression molded heat cure acrylic denture base resin (Lucitone 199) and this difference was statistically significant (p < 0.05). However, the surface roughness of polyamide denture base material (Lucitone FRS) was well within the accepted norm of 0.2 µm Radrmukesh.mds@gmail.comResearch912019sourface roughness,profilometer,compression moldingMukesh Kumar,VedPrakash Department of Dentistry, Shri Krishna Medical College and Hospital, Muzaffarpur, Bihar 842004, India,Dept. of Dentistry, Shri Krishna Medical College and Hospital, Muzaffarpur, Bihar 842004, India