ABSTRACT
Exfoliative cytology of the oral mucosa under distal- extension bases recorded by two different impression techniques: mucostatic and mucocompressive was investigated in this study. Eleven, patients were selected and divided into two groups [five in each group as one did not continue to the end of the study]. Each patient in the two groups received a mandibular distal-extension removable partial denture with an opposing complete maxillary denture. The mandibular partial dentures in the first group were constructed from mucostatic impressions, while, in the second group from mucocompressive impressions. All other steps of denture construction were made in a standard manner for all patients. Cytologic smears of oral mucosa under distal-extension bases were collected, fixed, stained with Papanicolaou's stain and then examined microscopically to calculate the Keratinization index. This cytologic examination was done : at the time of delivery and after : one mouth, two months and three months of denture wear. At each time interval, buccal, crestal and lingual smears were collected at the first molar region of the right side. The three smears were examined and then a mean Keratinization was calculated. Data of the cytologic examination of all patients were collected and statistically analyzed. It was found that Keratinization Index of the oral mucosa was significantly reduced under lower distal-extension bases recorded by either: mucostatic or mucocompressive technique. Maximum reduction was detected after one month of denture wear. The reduction in keratinization Index was significantly more under dentures constructed with mucocompressive impression technique than with mucostatic impression technique