Abstract
The relationship between phenytoin (DPH) levels in blood plasma or saliva and gingival hyperplasia were investigated in 36 epileptic severely handicapped patients who had been administrated with DPH for a long period of time in an asylum.
The DPH concentration of plasma (total), ultrafiltrated plasma (free), whole saliva or parotid saliva were determined with homogenous enzyme immunoassay. The grade of gingival hyperplasia were evaluated following Isikawa's criteria.
The results were as follows:
1) DPH concentration in parotid or whole saliva correlated to the free DPH of plasma. The concentrations in the saliva approximated the free DPH of plasma.
2) The ratios of each DPH concentration to the total plasma DPH were almost the same: 15.3% for free DPH,19.0% for parotid DPH,14.3% for whole saliva DPH.
3) These data suggest that the determination of concentration of DPH in whole saliva is a more beneficial method to monitor the effective concentration of protein unbound plasma DPH.
4) Through oral examination,32 out of 36 patients were found to be suffering from gingival hyperplasia: 14 mild,11 moderate and 7 severe cases respectively.
5) The comparison of DPH concentrations among the groups with severe gingival hyperplasia showed a significant difference between the mild and the severe cases in total plasma (p<0.001), in whole saliva (p<0.001), and in protein unbound plasma (p<0.001); between the mild and the moderate cases in total plasma (p <0.001), and in protein unbound plasma (p<0.05); between the moderate and the severe cases in whole saliva (p<0.02). Significant differences were also observed in the volume of DPH secretion per hour between the mild and the severe cases in whole saliva, between the mild and the moderate cases in parotid saliva.
6) A significant correlation was observed between the grades of gingival hyperplasia (grades 1 to 18) and DPH concentrations of total plasma (rxy=0.71, p<0.001), whole saliva (rxy=0.69, p <0.001), protein unbound plasma (rxy=0.57, p <0.01), parotid saliva (rxy=0.55, p <0.02); correlations were also observed between the grades of hyperplasia and the volume of secretion per hour of DPH of whole saliva (rxy=0.42, p <0.05) and parotid saliva (rxy=0.52, p <0.05).
7) These data positively suggest a relationship between the DPH concentration and gingival hyperplasia. However, totaly neglected oral dental hygiene found in severely hadicapped patients was considered to be related to aggravated gingival hyperplasia.
