Topcuoglu, Ozan, Ozyurt, Kulekci erties, such as antibacterial, antifungal, antiviral, to enhance ﬂuoride uptake by underlying dentin.17 antitumor and anti-inﬂammatory among others.2,3 Under these circumstances, we hypothesize that In addition, this material is still used as a remedy propolis, a well known anticariogenic material, in modern medicine due to a general “back to na- could augment the anticariogenic properties of ture trend”. GIC. The aims of the present study were to inves- The antibacterial and antifungal properties of tigate: (i) antibacterial effect of Turkish propolis propolis have been extensively investigated and, on S. mutans; (ii) antibacterial efﬁcacy of GIC con- although its chemical composition is linked to the taining propolis on S. mutans and (iii) effect of GIC phytogeographic origin, the activity of bee glue has containing propolis on S. mutans bioﬁlm formation. always been reported.4 Propolis may act against a wide range of bacteria, fungi, yeasts and viruses.2,4. MATERIAL AND METHODS The antimicrobial properties of this mixture of nat- Preparation of Ethanolic Extract of Propolis ural substances are mainly attributed to the ﬂavo- Propolis samples were produced by honey- none pinocembrin, to the ﬂavonol galangin and to bees (Apis mellifera L.) in the region of Yomra, the caffeic acid phenethyl ester, with a mechanism Trabzon, Turkey, rich in Picea orientalis, Fagus of action probably based on the inhibition of bacte- orientalis,Castanes sativa, Rhodddendron ponticum, rial RNA-polymerase.5 Rhododendron luteum, Rubus caucasicus.18 Propolis Although propolis has shown variable activ- was provided by Trabzon Agricultural Development ity against different bacteria and there are many Cooperative. Hand collected propolis were kept products containing propolis on the world market desiccated and in the dark up to their processing. such as ethanol extracts, toothpastes and mouth The samples were grinded (Ultra-Centrifugal Mill rinses, few studies have been made for the anti- ZM 200, Retsch GmbH, Germany) and bottled in 10 bacterial activity of propolis on oral microorgan- g portions. They were then dissolved in 20 mL of isms.6,7 Recent studies have shown the anti-caries ethanol (70%, w/v) by magnetic mixer for 48 h at potential of propolis.7-9 Propolis samples reduced room temperature. Lastly, rough particles were the incidence of caries and dental plaque accumu- removed from propolis extract by ﬁlter. lation in vivo.9,10 Two action mechanisms have been associated with the anti-caries/anti-plaque prop- Bacterial Strain and Inoculum Preperation erties of propolis: (i) antimicrobial activity against Streptococcus mutans ATCC 25175 type strain cariogenic bacteria (such as Streptococcus mutans was used throughout the study. Bacteria were cul- and Streptococcus sobrinus), and (ii) inhibition of tured overnight at 37°C in the Brain Heart Infusion glucosyltransferase enzymes (GTFs) activity.10,11 Broth (BHI, Merck KGaA 64271 Darmstadt, Ger- The dental bioﬁlm formation on tooth surfaces many) and used as inoculum. The turbidity of the is a prerequisite for development of both den- suspension was adjusted to the McFarland 0.5 tur- tal caries and periodontal disease. The level of bidity standard (Densimat, BioMerieux, France). mutans streptococci (S. mutans and S. sobrinus) in Determination of the Minimal Inhibitory Con- dental bioﬁlm is associated with caries develop- centration (MIC) ment.12 Caries is one of the primary causes of cast The agar dilution method was used as recom- restoration failure, so an ideal luting agent would mended by the Clinical and Laboratory Standards actively prevent caries at the restoration-tooth in- Institute.19 Serial two-fold dilutions of EEP were terface. The popularity of the glass ionomer luting prepared in Mueller-Hinton agar (MHA, Oxoid cements is undoubtedly due to the ﬂuoride release Ltd, Basingstone, Hempshire, UK) supplemented associated with these materials and the presumed with 5% deﬁbrinated sheep blood. Agar dilutions beneﬁt of reduced caries.13 Glass ionomer cement ranged from 0.1 to 50 µg/mL. Each antimicrobial has been shown to increase the ﬂuoride ion con- test was also re-performed with plates contain- centration in the saliva in the short-term, in vivo.14 ing the culture medium plus ethanol as solvent When used as a restorative material, both conven- control. Each plate was then inoculated with a tional and the resin-modiﬁed glass ionomers have multipoint inoculating device (Steers replicator), been shown in vitro to reduce artiﬁcial caries15 which delivered a ﬁnal inoculum of approximately and in vivo to remineralize carious lesions16 and 105 CFU per spot. The inoculum size was veriﬁed October 2012 - Vol.6 429 European Journal of Dentistry