Aim of the work. Objectives of the study are the following: quantify and identify microorganisms in the dental plaque
of patients with black stain; test in vivo and in vitro efficacy of two mouthwashes; identify a protocol.
Materials and methods. The research protocol included a clinical and a microbiological stage. 63 patients between 2
and 15 years with black stain were selected, then divided into three groups. In Group 1 (19 patients) no mouthwash was
prescribed. In Group 2 (21 patients) was prescribed a fluoride mouthwash (Sodium Fluoride 0,05%). In Group 3 (23
patients) a chlorhexidine 0,12% mouthwash was prescribed. The microbiological stage provided analysis of pigmented
plaque through bacterial count and identification tests and aura of inhibition on agar plate to evaluate the inhibitory
power of the mouthwashes examined.
Results. It was highlighted a strong decrease in index of pigmented plaque in Group 3 than Groups 1 and 2. The
microbiological analysis revealed a decrease in bacterial count higher in Group 3 than Groups 1 and 2. The bacteria
identified the most were Clostridia. The chlorhexidine mouthwash was more effective than fluorine mouthwash on
bacterial growth.
Conclusions. The use of mouthwash in conjunction with periodic specialist visits is essential to assist oral hygiene at
home. It is assumed that the mouthwash with chlorhexidine 0,12% is the most effective in reducing black stain in vivo and
in vitro