Figure 1. The three-dimensional pellet culture for porcine primary pulp cells compared with the monolayer culture. (A) Morphological changes in the pellet during culture on day 7, day 14, and day 21 (H–E stain). Note the decrease of cell number and increased matrix on day 21. (B) The changes in cell numbers during pellet cultures of porcine pulp cells compared with monolayer culture in 35-mm dish. Each point is expressed as the mean ± SD of 6 determinations. Note the lack of proliferation of cells in pellet cultures. (C) The changes in alkaline phosphatase activity. Each point is expressed as the mean ± SD of 6 determinations. (D) Real-time RT-PCR analysis of 1(I)collagen, Dmp1, Dspp, enamelysin/MMP20, and Phex expression in pellet cultures compared with monolayer cultures. The experiment was repeated 3 times, and 1 representative experiment is presented. The relative percentage of expression was shown in relation to the highest value as 100% after normalization against ß-actin. Solid lines represent pellet cultures and dashed lines monolayer cultures.