The purpose of present study is to compare the effect of treatment using $Guidor^{(R)}$ as a barrier membrane in conjunction with platelet-derived growth factor and insulin like growth factors on experimental dehiscence defects. Following the resection of premolar crowns, roots were submerged. After 12 weeks of healing period, experimental dehiscence defects of 4mm in height and 4mm in width were surgically created on the mid-facial aspect of the lower premolar roots in each of 4 adult dogs. After root planning and demineralization of the root surface with citric acid, the control groups received 4% methylcellulose gel only, the test group I received 4% methylcellulose gel and were covered by $Guidor^{(R)}$ and the test group II were treated with PDGF and IGF and 4% methylcellulose gel with $Guidor^{(R)}$ coverage. Histological and histomorphometric analysis following 8 weeks of healing revealed the following results. 1. The new bone formation showed no statistically significant difference in all groups with $0.59{pm}0.82mm$($14.03{pm}19.60%$) for control, $0.70{pm}0.39mm$($16.30{pm}9.01%$) for group I, $0.87{pm}0.76mm$($18.74{pm}16.03%$) for group II. 2. The new cementum formation showed no statistically significant difference in all groups with $0.54{pm}0.48mm$($l6.38{pm}14.57%$) for control, $0.95{pm}0.38mm$($23.43{pm}9.30%$) for group I, $1.01{pm}0.75mm$($22.10{pm}16.ll%$) for gorup II. 3. The root resorption showed statistically significant differences betweenthe control group and all test groups(p<0.05) with $2.11{pm}0.53mm$($52.93{pm}12.32%$) for control, $0.63{pm}0.27mm$($15.32{pm}7.05%$) for group I, $0.89{pm}0.33mm$ ($19.26{pm}7.11%$) for group II. On the bases of these results, there were no statistically difference between treatment using resorbable membrane and resorbable membrane in conjunction with PDGF and IGF in the dehiscence defects, where it was difficult to maintain space. The use of membrane seemed to be more effective in the inhibition of root resorption.