Objective: The present study aimed to determine the chemical composition of three commercially available gutta-percha brands (Hygenic, Maillefer and Meta), detect the ability of some essential oils to dissolve them and finally evaluate the efficacy of the effective oils in removing the filling material of teeth obturated with those three gutta-percha brands and Zinc oxide eugenol sealer. Materials &Methods: Evaluation of gutta-percha composition was done initially separating the organic fraction from the inorganic one after dissolving in chloroform and centrifugation. The organic fraction was then dissolved in acetone to separate pure gutta-percha from wax/resin; those were separated from each other by dissolving in absolute alcohol (99, 9%). Weight of each component was recorded. Identification of inorganic components was done by XRD. Each of Thirty five essential oils was tested for its ability to dissolve # 50 gutta-percha cones of each brand at room temperature (28-300C) and at 400C. The dissolution was tested visually every min up to 15 min to record dissolution time. Distilled water and chloroform, were used as -ve & +ve control respectively. Three most effective oils from the previous experiment were selected in the re-treatment study of teeth obturated with the three brands of gutta-percha. Navel orange at r.t, Cardamom at 400C and Common mandarin at 400C were used. Chloroform at r.t was used as positive control group. Sixty single rooted teeth were prepared using step-back technique using # 50 cone as master apical cone. The teeth were equally divided into three groups representing the three gutta-percha brands, obturated using lateral compaction and Zinc oxide eugenol sealer. Teeth were kept in 370C and 100% humidity for three months. After this period, each group was equally subdivided into four subgroups according to the solvent used. Retreatment was done using H files in crown-down starting with #70 till # 50 manners. Retreatment time was recorded. Roots were split into two halves ready for the evaluation by the stereomicroscope to determine the amount % and the type of the remaining debris. Results were statistically analyzed. Results The inorganic part ranged between; 68.5% to 84%, while organic part was 16% to 31.5%. Maillefer brand contained the highest inorganic percent (84%). Meta contained the highest pure gutta-percha percent (23.6%). Hygenic brand showed the highest Wax/Resin percent (9.8%). BaSO4 was found in all tested brands. Eighteen oils from three families namely Rotaeae, Labiateae and Zingibraceae were effective at varying degrees, with efficiency increased by elevating temperature to 400C. Maillefer recorded the highest statistically significant retreatment time while Meta recorded the lowest time. For solvents; Navel orange recorded the highest statistically significant time, while common mandarin recorded the lowest statistically significant time. Meta brand left highest amount of remaining debris after retreatment followed by Maillefer, while Hygenic had the lowest amount. Common mandarin left the highest debris, while Cardamom left the lowest debris amount; chloroform had extreme range among brands. Apical region contained the highest remaining debris percent. Both the cervical and middle regions contained sealer only as remaining debris, while the apical region contained both sealer and gutta-percha as remaining debris. Under the conditions of the present study it can be concluded that: 1. Difference in gutta-percha brand composition may affect the dissolution in organic solvents. 2. Not all herbal plants tested were effective solvents for gutta-percha brands. 3. Warming can lead to faster dissolution effect of solvents. 4. The time of retreatment was inversely proportional to the amount of remaining debris. 5. Debridement was into equal along the whole root canal length.