Subjects were randomly assigned to one of three groups using a computerized assignment procedure (Random Sequence Generator, www.random.org) generated by the examiner A.G. Each subject was given an identical number between 1 and 42. Participants received bottles with one of the three solutions under investigation. Neither patients nor clinicians (surgeons and examiner A.G.) were informed about the identity of mouthrinse administered in each case (double - blind design). Masked bottles were given to participants by a third independent person who was not a dentist (member of Postgraduate Clinic's assistance staff).