Recovery of multispecies oral biofilms is investigated following treatment by chlorhexidine gluconate (CHX), iodine-potassium iodide (IPI) and Sodium hypochlorite (NaOCl) both experimentally and theoretically. Experimentally, biofilms taken from two donors were exposed to the three different antibacterial solutions (irrigants) for 10 minutes, respectively. We observe that (a) bacterial cell densities decline for a week after the exposure and the trend reverses after one week; the biofilms fully return to pretreatment levels after fifteen weeks; (b) NaOCl is shown as the strongest antibacterial agent in the treatment of the biofilms; (c) multispecies oral biofilms from two different donors showed no difference in their susceptibility to all the irritants. Guided by the experimental evidence, we develop a mathematical model for biofilms accounting for multiple bacterial phenotypes, quorum sensing molecules, and growth factors to describe the nonlinear time evolution behavior of the biofilms. The model captures the biofilm evolution after antibacterial treatment very well. It reveals the crucial role played by the growth factor in biofilm recovery and verifies that the source of the biofilms has a minimal effect to their recovery mechanisms. The model is also applied to model biofilm treatment by CHX at different ages. Good agreement results with the experimental data are attained as well, demonstrating its applicability to modeling biofilm dynamics.