The study was carried out on six patients with acquired maxillary defect (class I Aramany's classification) who are in need of definitive obturator. This study was done to compare the microbial colonization of heat cured acrylic resin and versacryl in obturators restoring acquired maxillary defects.Selected patients received a metal framework prosthesis with heat cured acrylic resin bulb extending into the surgical site. At time of delivery after complete adjustment and relief were done, a swab was obtained from the patient's mouth from the nasal surface of the surgical defect which represents the base line for this group. Another swab was taken after two and four weeks from wearing the obturator for microbiological evaluation and the swab was taken each time from the same place. The heat cured acrylic bulb was replaced with versacryl and the same steps were carried out as the heat cured group.Swabs were immediately cultivated into three different media Blood Agar, Sabouraud Dextrose Agar and Macconkey media and incubated for microbiological evaluation. The identification and quantification of the isolated microorganisms were performed using conventional microbiological cultivation method. Finally, the collected data was tabulated and statistically analyzed. The results obtained from this study revealed that, both conventional heat cured acrylic obturator and versacryl obturator bulb has the affinity to support microbial growth and the difference between the two groups was insignificant. However, patients were more satisfied with the versacryl obturator bulb.Based on the analysis of the present microbiological study and according to their limitations, it can be concluded that the versacryl lining material and heat cured acrylic obturators can be used for construction of the obturator bulb. However, the versacryl looks to be more clinically accepted by the patients.