Caries risk assessment is a valuable clinical procedure that in many ways facilitates implementation of preventive procedures in children with high risk of caries. The aim of this study was to investigate the effectiveness of five different caries preventive procedures in vivo. One hundred children, aged 4-5 and 10-12 years, were divided into five groups (20 per group) and treated with different preventive procedures (amine fluoride solution, professional prophylactic paste, chewing gum containing xylitol and fluoride, chlorhexidine solution, or chlorhexidine-fluoride gel). During a period of two months, five measurements were performed and the following variables evaluated: Streptococcus (S.) mutans and lactobacilli count (LB), oral hygiene index (OHI), and amount of stimulated saliva. Results showed the highest reduction in the number of bacteria to be achieved by the application of professional prophylactic tooth paste and daily use of chewing gum containing xylitol and fluoride (p<0.001). In these children, S. mutans count was reduced by class 1 and LB to <104 CFU/mL after two months. In conclusion, professional tooth cleaning and use of chewing gum with xylitol and fluorides on a daily basis could be very effective protocol in controlling caries risk factors in children.Procjena rizika za razvoj karijesa vrijedan je klinički postupak koji u mnogočemu olakšava uvođenje preventivnih postupaka u visokorizične djece za karijes. Cilj ovog istraživanja bio je ispitati djelotvornost pet različitih karijes preventivnih postupaka in vivo. Stotinu djece, razdijeljene u pet skupina, od kojih je u svakoj bilo 20-ero (u dobi od 4-5 i od 10-13 godina) tretirano je različitim preventivnim postupcima (amin fluoridnom otopinom, profesionalnom profilaktičkom pastom, žvakaćom gumom koja sadrži ksilitol i fluorid, otopinom klorheksidina, gelom koji sadrži klorheksidin i fluor). Tijekom dvomjesečnog razdoblja obavljeno je pet mjerenja i evaluirane su sljedeće varijable: broj Streptococcus mutans (SM) i Lactobacilli (LB), indeks oralne higijene (OHI) i količina stimulirane sline. Rezultati su pokazali da je najveće smanjenje broja bakterija postignuto primjenom profesionalne profilaktičke paste i svakodnevnim žvakanjem žvakaće gume koja sadrži ksilitol i fluorid (p<0.001). Kod te djece nakon dva mjeseca broj SM-a smanjen je na klasu 1 i LB-a na <104 CFU/ml. Zaključno, profesionalno čišćenje zuba i upotreba žvakaće gume s ksilitolom i fluoridima na dnevnoj bazi mogla bi biti vrlo djelotvorni način za kontrolu rizičnih čimbenika za nastanak karijesa u djece
