Influence of photodynamic therapy and diode laser on successful endodontic treatment of young permanent teeth and biostimulation of stem cells from apical papilla

Abstract

Stem cells from apical papilla (SCAPs) represent a homogeneous cell population which differentiates into primary odontoblasts and form primary root dentine. Young permanent teeth, more prone to dental trauma and developmental anomalies, have greater susceptibility to develop endodontic infections. During endodontic treatment of young permanent teeth, control of infection represents a necessary step in creating conditions for further tissue regeneration and healing. Due to good antibacterial potential, the application of photodynamic therapy and a high-power diode laser has been recommended, as addition to standard endodontic protocol. The Aim of this study was to investigate biocompatibility of diode laser and photodynamic therapy on stem cells from apical papilla, as well as the antibacterial effect of standard disinfection, lasers, and materials for definitive root canal obturation in endodontic treatment of young permanent teeth. Materials and methods: SCAPs were isolated and characterized by internationally accepted criteria for mesenchymal stem cells. Biocompatibility of diode laser and photodynamic therapy was investigated on characterized stem cells by the mitochondrial activity assay (MTT assay) and cells viability assay (Neutral red assay) after 1 hour, 1 and 7 days. Lasers bbiostimulation effect on cells migration was evaluated by scratch assay, while the effect on osteogenic differentiation was investigated by measurement of alkaline phosphatase (3 7, and 14 days) and Alizarin red staining. Relative gene expression analysis and protein staining of selected markers for odonto/osteogenic differentiation, have been performed as well after 21 days. In a randomized controlled clinical study, patients have been relocated in 3 study groups. Antibacterial effect was evaluated after standard endodontic treatment, as well as after diode laser application and photodynamic therapy, in corresponding groups. Samples were seeded on microbial plates, and additionally analyzed by molecular methods. Antibacterial effects of calcium hydroxide, mineral trioxide aggregate, and calcium silicate with the addition of bismuth oxide were investigated on clinical isolates, by the method of double agar diffusion test in three time periods (1, 3, and 24 hours)...

Uvod: Matične ćelije poreklom iz apikalne papile (SCAP) predstavljaju homogenu ćelijsku populaciju koja diferentuje u primarne odontoblaste i formira primarni dentin korena. Mladi stalni zubi, usled sklonosti ka povredama i razvojnim anomalijama, su u velikom riziku za nastanak endodontskih oboljenja. Tokom endodontskog lečenja mladih stalnih zuba kontrola infekcije predstavlja neophodan korak u stvaranju uslova za regeneraciju i zarastanje. Usled dobrog antibakterijskog potencijala, predložena je upotreba fotodinamske terapije i diodnih lasera velike snage u endodontskom lečenju, kao dodatak važećim protokolima. Cilj ovog istraživanja bio je da se ispita biokompatibilnost diodnog lasera i fotodinamske terapije na matičnim ćelijama poreklom iz apikalne papile zuba, kao i antimikrobno dejstvo tradicionalnih antimikrobnih sredstava, lasera, i materijala za definitivnu opturaciju kanala korena u endodontskom lečenju mladih stalnih zuba. Materijali i metode: Ćelije iz apikalne papile su izolovane i okarakterisane prema međunarodno definisanim kriterijumima za mezenhimalne matične ćelije. Na okarakterisanim matičnim ćelijama poreklom iz apikalne papile ispitana je biokompatibilnost diodnog lasera i fotodinamske terapije testom mitohondrijske aktivnosti (MTT) i direktnim testom vijabilnosti ćelija (Neutralno crveno) nakon 1 sata, 1 i 7 dana. Biostimulativno dejstvo lasera na potencijal migracije ispitano je testom ogrebotine, dok je uticaj na potencijal osteogenog usmeravanja ispitana merenjem alkalne fosfataze (3, 7 i 14 dana) i bojenjem Alizarin crvenim. Ispitan je i nivo relativne genske ekspresije i specifično bojenje proteina za markere odonto/osteogene diferencijacije, nakon 21 dana. U randomizovanoj kontrolisanoj kliničkoj studiji, pacijenti su raspoređeni u 3 ogledne grupe. Antimikrobno dejstvo je ispitano nakon dejstva standardnih antimikrobnih sredstava, kao i nakon dodatnog dejstva diodnog lasera i fotodinamske terapije u odgovarajućim grupama...