Objective: The aim of this study was to establish a culture model of adult odontoblasts in situ to determine the presence of gelatinolytic enzymes and to analyze the effect of TGF-beta1 on gelatinase A and B expression.Methods:Fresh healthy third molars were prepared from 20-30 year old people.The root was dissected from the crown,then the pulp was pulled out and to make odontoblast stay in the crown.The odontoblasts in the crown were cultured in the serum medium or serum-free medium for up to 7 days,and the medium was collected and replaced daily.The condition,morphology,location and activity of the odontoblast were then examined. Odontoblasts were first cultured in serum-free OPTI-MEM medium to establish baseline expression.The culture medium was harvested daily and replaced with fresh medium.After two days of culture,the conditioned medium was harvested and replaced with fresh medium containing 10 ng/mL TGF-beta1 (n = 3),while controls (n = 3) were cultured in the medium containing the BSA carrier without TGF-beta1.The culture was continued for another five days with daily medium replacement.Each medium sample was analyzed by zymography to analyze gelatinase production.Results: Odontoblasts maintain activity and good cell morphology during 7 days of the initial culture, and there were no differences between the cells cultured in serum-free or serum-containing media. The level of gelatinase A remained constant up to 7 days with or without TGF-beta1, On the other hand,while the level of gelatinase B remained constant up to 7 days without TGF-beta1,was markedly increased upon TGF-beta1 treatment from the day 5 and remained increased up to the day 7.Conclusion: This modle allows for the study of adult odontoblast function in situ,and TGF-beta1 may regulate gelatinase expression in odontoblast,and may be a major candidate of regulatory factor in the secretory activity of the odontoblasts.