The potential of essential oils towards bacteria from infected root canals of young permanent teeth

Teza istraţuje potencijal odabranih etarskih ulja prema izolatima iz inficiranih korenskih kanala. Po prvi put daje uvid u mikrobiom mladih stalnih zuba sa apikalnim periodontitisom i istiĉe prisustvo fakultativnih (Streptococcus, Actinomyces, Enterococcus) i striktnih anaeroba (Veillonella, Prevotella, Fusobacterium). Prikazuje hemijski sastav ulja: Cinnamomum camphora cineoliferum, Melaleuca ericifolia, Eucalyptus citriodora, Leptospermum petersonii, Thymus zygis i vrsti Pelargonium i Cymbopogon (P. roseum, P. graveolens, C. citratus i C. martinii). Istraţivanje antibakterijskog efekta prema referentnim i kliniĉkim sojevima pokazalo je manju osetljivost izolata i dalo poredak ulja po efikasnosti: T. zygis ˃ C. martinii ˃ C. citratus > L. petersonii > P. graveolens > P. roseum > E. citriodora > M. ericifolia > C. camphora cineoliferum. Ulja P. graveolens, L. petersonii i C. citratus inhibirala su samo inicijalnu fazu formiranja biofilmova, dok je efekat ulja C. martinii i T. zygis bio inhibitoran i na biofilmove u nastajanju i na one preformirane. Napravljen je novi naĉin njihove isporuke u vodenoj fazi u formi nano- (C. martinii), odnosno mikroemulzija (T. zygis). Antibiofilmni efekat emulzija, ispitan na eksperimentalno inficiranim kanalima ekstrahovanih zuba, bio je obećavajući i u sluĉaju samostalne primene, ali i u finalnoj irigaciji. Rezultate je potvrdila SEM mikroskopija. Inicijalna procena bezbednosti primene, kroz testove citotoksiĉnosti na MRC-5 ćelijama, pokazala je da je, u ostvarenim eksperimentalnim uslovima, citotoksiĉnost analiziranih ulja i triantibiotske paste bila uporediva. Rezultati ohrabruju dalja istraţivanja u cilju praktiĉne primene ulja i njihovih emulzija u terapiji infekcija pulpnog prostora mladih stalnih zuba.The thesis investigates the potential of selected essential oils towards isolates from infected root canals. For the first time, it provides insight into the microbiota of young permanent teeth with apical periodontitis and emphasizes the presence of facultative (Streptococcus, Actinomyces, Enterococcus) and strict anaerobes (Veillonella, Prevotella, Fusobacterium). It shows the chemical composition of the essential oils of Cinnamomum camphora cineoliferum, Melaleuca ericifolia, Eucalyptus citriodora, Leptospermum petersonii, Thymus zygis and from the species Pelargonium and Cymbopogon (P. roseum, P. graveolens, C. citratus and C. martinii). Investigation of the antibacterial effect towards reference and clinical strains suggested following order of efficiency: T. zygis ˃ C. martinii ˃ C. citratus> L. petersonii> P. graveolens> P. roseum> E. citriodora> M. ericifolia> C. camphora cineoliferum. The essential oils of P. graveolens, L. petersonii and C. citratus inhibited only the initial phase of biofilm formation, while the ones of C. martinii and T. zygis inhibited both emerging and preformed biofilms. A new way of the delivery of C. martinii and T. zygis essential oils, in the form of nano- and microemulsion, respectively, was made. The antibiofilm effect of emulsions, tested on experimentally infected canals of extracted teeth, was promising during singular application, but also in the final irrigation. The results were confirmed by SEM microscopy. Cytotoxicity tests on MRC-5 cells showed that toxicity of the analyzed oils and triple antibiotic paste, used as control, was comparable. Results encourage further research for the practical application of the oils and emulsions in the treatment of infected root canals of young permanent teeth with apical periodontitis