Probiotics or health-beneficial bacteria have only recently been introduced in dentistry and oral medicine after years of successful use in mainly gastro-intestinal disorders. The concept of bacteriotherapy and use of health-beneficial micro-organisms to heal diseases or support immune function was first introduced in the beginning of the 20th century. Later the concept lead to the development ...

Users of structural equation modeling (SEM), a method that has also been known as causal modeling, have learned to tread lightly around the subject of causality. After all, the empirical raw material of SEM is typically a covariance matrix derived from nonexperimental data, and research dogma indicates that this is insufficient for making statements about cause-and-effect relations. At least as...