Collection and identification of plant parts and dental caries pathogens. Collection of plant materialsThe small branches of Z. zanthoxyloides and T. locally available glaucescens were collected from the local main market in Ogbete Enugu and were authenticated by Prof. Okigbo RN of the Department of Botany, Nnamdi Azikiwe University, Awka. These plant materials were dried in the sun for two weeks and then cut into pieces of approximately 15 cm and transferred to the oven at 45°C for 20-30 minutes before being reduced to a fine powder with the aid of a mechanical grinder. The powdered plant materials were collected and stored in a tightly covered glass jar for further studies. Collection and Retrieval of Caries Samples Dental extracts of 20 (twenty) patients with clinical features of dental caries were collected from the clinic of School of Dental Technology and Therapy, Trans-ekulu, Enugu. The patients consisted of 8 males and 12 females aged between 16 and 40 years. The samples were collected under strict aseptic conditions. Before collecting the dental caries sample, the patient was made to rinse the tooth with water. The tooth and surrounding field were cleaned with 3% hydrogen peroxide and then decontaminated with 2.5% sodium hypochlorite solution. Food debris on the chewing surface was removed using a dental excavation tool. The tooth was then extracted by a doctor and then introduced into 20 ml Brain Heart Infusion (BHI) broth in special sterile bottles with screw caps. The dental caries sample was collected from the extracted tooth using an excavator under aseptic conditions. Clinical samples were mixed well using a magnetic stirrer before incubation. Samples were then inoculated using the streak plate technique onto Sabouraud Nutrient Dextrose Agar under various culture conditions: aerobic, microaerophilic, and anaerobic culture conditions for each patient sample (Holding and Colee, 1971). The isolated organism was identified on the basis of morphological, cultural and biochemical characteristics according to standard procedures (Holding and Colee, 1971).2.3 PREPARATION AND EXTRACTION OF PLANT MATERIALS. Ethanol extraction20 g of fine powdered stem of Z. zanthoxyloides and T. glaucescens were weighed and immersed in 200 ml of ethanol in a conical flask and kept at room temperature (25°C) on a rotary shaker for 48 h. After 48 hours, filtered on Whatman No1 filter paper; the solvent was allowed to evaporate and stored at room temperature until use.2.5 IDENTIFICATION OF THE ISOLATESThe isolated organisms were identified using subcultures, Gram staining technique and biochemical tests such as catalase test, indole test, coagulase, methyl red test, oxalose test, sugar fermentation test.