RESUMEN
Aim: The primary aim of this longitudinal study was to evaluate additional effects of 4-weekchlorhexidine digluconate (CHX) gel treatments to control Aggregatibacter actinomycetemcomitanscounts in children after professional dental prophylaxis. Porphyromonas gingivalis and Streptococcusmutans counts were also determined to evaluate the secondary effects of anti-plaque treatments onmicrobial shifts. Methods: Twenty-six children with A. actinomycetemcomitans counts >4 log10/mL of saliva and/or Quigley-Hein plaque index >3.0 were enrolled in this study. Patients wererandomly assigned to groups GI (placebo gel), GII (0.5% CHX gel), GIII (1% CHX gel), and GIV(2% CHX gel). Four sessions of treatment were performed during 4 weeks after a session ofprofessional dental prophylaxis. Real-Time polymerase chain reaction (PCR) was used todetermine viable microorganism counts in non-stimulated whole saliva samples collected atbaseline, one week, one month and three months after interruption of treatments. Results: Areduction of all bacterial counts was detected after the 3-month follow-up in all groups. Lowercounts of P. gingivalis were achieved from 1 week on after treatments. The 2% CHX concentrationseemed to contribute to lower A. actinomycetemcomitans levels and increase S. mutans levels.Conclusions: Professional dental prophylaxis was effective to control salivary levels of A.actinomycetemcomitans, P. gingivalis and S. mutans. Additional antimicrobial effects, however,were not observed by the combination of professional dental prophylaxis and 4-week chlorhexidinegel treatments.