We learned that the maximum interval between visits should be 10-14 days and that bacterial accumulation can begin after 14 days. Is that correct?

That is true if the temporary filling leaks, but if it leaks, there is no point in carrying out treatment over separate visits anyway. It is therefore very important to place a leak-tight temporary filling, and in that situation the interval can be longer. In teeth with large lesions in which caOH2 has been placed, this interval can be 3-8 weeks. In this situation, a temporary filling made with composite would be ideal.