Uticaj hidroksiapatita na apeksogenezu u majmuna - klinička studija

Management of the affected pulp in teeth with incomplete root formation is still an issue. Calcium hydroxide and other materials have been employed for this purpose to a greater or lesser success. Bioceramic materials are in the last decades well established in a number of different medical fields. Having its constituents the same as those of the unorganic portion of bone tissue, hydroxiapatite (HAP), one of the two forms of calcium-phosphate ceramics, is already accepted in endodontic treatment of teeth with completed root formation. The aim of this study was to examine apexogenesis in teeth with immature roots, following the use of HAP on their affected pulp. Examination was performed on eight young monkeys (Cercopithecus Aethiops) with incomplete root development. The 100 μm synthetic HAP material was applied on 32 teeth divided into two groups of 16 teeth each. In one group teeth underwent pulpotomy, in the other high pulpotomy. Evaluation of root growth was recorded from radiographs (pre-treatment, 3 and 12 months following treatment) and by Demjrian's scale for dental maturity and tooth age determination. On the basis of radiographic analysis, immature teeth with affected pulp treated with HAP, both with pulpotomy and high pulpotomy, reached the same stage of root development as control teeth in 50% of cases at 3-months radiographic assessment. After 12 months all tested teeth had the same rate of root development as control teeth, except for 1 of 8 with high pulpotomy. Dentinal bridge was radiographically visible in 50% and 87.5% of pulpotomized teeth after 3 and 12 months, respectively. Neither obliteration of the root canal, presence of denticles nor the presence of deformities in the periapical region were found in any of the observed teeth.Lečenja aficirane pulpe zuba sa nezavršenim rastom korena je još uvek predmet stručnih i naučnih rasprava, između ostalog i zbog neželjenih efekata tradicionalnih preparata na bazi kalcijum hidroksida. Biokeramički materijali se već nekoliko decenija primenjuju u različitim granama medicine, a hidroksiapatit, kao jedna od dve forme kalcijum-fosfatne keramike, ima gotovo istovetan sastav kao neorganski deo kosti, pa je već prihvaćen u endodontskom lečenju zuba sa završ enim rastom korena. Cilj ovog rada je bio da se ispita uticaj hidroksiapatita na apeksogenezu u zuba sa nezavršenim rastom korena i aficiranom pulpom. Ispitivanjem je bilo obuhvaćeno na osam mladih majmuna Cercopithecus Aethiops sa nezavršenim rastom korena zuba. Sintetički hidroksiapatit, veličine čestica od 100 μm je primenjen na trideset dva zuba, podeljenih u dve jednake grupe kod kojih je všena apulpotomija, odnosno visoka pulpotomija. Rendgenološ ka evaluacija rasta korena zuba je vršena pre terapije, kao i tri i dvanaest mesici posle primene HAP, a na osnovu Demjrianove skale za određivanje zrelosti zuba. Na osnovu rendgenološke analize posle 3 meseca je nađeno da je brzina razvoja korena kako pulpotomisanih, tako i visoko pulpotomisanih zuba kod kojih je primenjen HAP bila u 50% slučajeva ista kao kod kontrolnih zuba. Posle 12 meseci stepen razvoja korena zuba je u svih ispitivanih zuba (osim kod jednog od osam zuba sa izvršenom visokom pulpotomijom) bio isti kao u kontrolnih zuba. Dentinski most je bio vidljiv radiološkom analizom u 50% odnosno 87,5% eksperimentalnih zuba posle 3, odnosno posle 12 meseci. Ni u jednom pregledanom zubu rendgenološki nije uočena obliteracija kanala korena, kao ni dentikli ni deformiteti u periapeksnom predelu

Uticaj hidroksiapatita i plazme bogate trombocitima na proces apeksogeneze kod majmuna

There are very few data about the effects of endogenous growth factors in vital pulp therapy, and still they are often controversial. This study was undertaken with the aim to evaluate the effects of platelet rich plasma (PRP) in conjugation with hydroxyapatite (HAP), as pulp capping materials, on root and periodontium formation. Eight young monkeys (Cercopithecus Aethiops) with permanent dentition and incomplete root formation were involved in this study. After pulpotomy, the pulp lesion was capped with calcium hydroxide (control), HAP (experimental) or HAP in conjugation with PRP (experimental). Six moths later, the animals were sacrificed, the tissue was removed en block, and prepared for histological analysis in a routine way. The results of histological analysis revealed that the healing process, characterized by dentin bridge formation, maintained morphological and functional integrity of dental pulp and complete formation of dental root and surrounding periodontium. The inflammatory reaction was scored as mild to moderate, in almost all samples in all groups, suggesting the biocompatibility of the used materials. Materials used in this study are convenient as capping agents, contributing in maintaining the integrity of the pulp tissue and facilitating root and periodontium formation. According to histological data it could be suggested that hydroxyapatite in conjugation with endogenous growth factors, represent a superior alternative to other materials used in this study.Podaci iz literature o primeni faktora rasta u vitalnoj terapiji pulpe su oskudni i često kontraverzni. Cilj našeg rada je bio da se ispita uticaj plazme bogate trombocitima u kombinaciji sa hidroksiapatitom, kao materijala za direktno prekrivanje pulpe, na završetak rasta korena i formiranje okolnog parodoncijuma. Istraživanje je sprovedeno na osam mladih majmuna (Cercopithecus aethiops), sa stalnom denticijom i nezavršenim rastom korena. Nakon pulpotomije, pulpna lezija je prekrivena kalcijum hidroksidom (kontolna grupa), hidroksiapatitom (eksperimentalna grupa I) ili hidroksiapatitom u kombinaciji sa plazmom bogatom trombocitima (eksperimentalna grupa II). Šest meseci kasnije životinje su žrtvovane, a uzeto tkivo pripremljeno je za histološku analizu. Rezultati histološke analize ukazali su da je zarastanje bilo karakterisano stvaranjem mineralizovanog dentinskog mostića, uz očuvanje morfološkog i funkcionalnog integriteta pulpe i završetak rasta korena i okolnog parodoncijuma u uzorcima svih ispitivanih grupa. Zapaljenska reakcija je gotovo u svim ispitivnim uzorcima bila ocenjena kao blaga ili umerena, što govori u prilog biokompatibilnosti primenjenih materijala. Na osnovu dobijenih rezultata može se reći da su svi primenjeni materijali pogodni za direktno prekrivanje pulpe, da doprinose očuvanju integriteta pulpe i ubrzavaju završetak rasta korena i formiranje apikalnog parodoncijuma, s tim što hidroksipatit u kombinaciji sa endogenim faktorima rasta predstavlja superiorniju alternativu u odnosu na druge materijale korišćene u ovoj studiji

Effects of bone tissue engineering triad components on vascularization process: comparative gene expression and histological evaluation in an ectopic bone-forming model

Vascular development has a great significance in the osteogenic process and in bone tissue engineering (BTE). BTE is based on various combinations of three principal types of components: biomaterials as scaffolds, regulatory signals and cells. The aim of our study was to evaluate, at gene expression and histological level, the effect of BTE triad components on the vascularization process in an ectopic bone-forming model in mice. Bone mineral matrix (BMM) was used as a scaffold and a carrier, platelet-rich plasma (PRP) as a source of regulatory signals and adipose stem cells (ASCs) as a source of cells for endothelial differentiation, in order to show how and to what extent the biological enrichment of BMM influences the outcome of the osteogenic process and its key precondition, vascularization. Implants composed of BMM, PRP and ASCs in vitro induced into endothelial cells (EPB implants) and implants composed of BMM and PRP (PB implants) were compared with implants composed of BMM only (B implants). More pronounced endothelial-related gene expression and stronger VCAM-1 (vascular cell adhesion molecule-1) immunoexpression were observed in EPB implants in comparison with PB and B ones at later time points of the in vivo experimental period. Osteopontin gene expression and immunoexpression of osteopontin were significantly higher in EPB compared to PB and B implants. Therefore, addition of ASCs combined with PRP to BMM improved the vascularization process in the ectopic bone-forming model, which makes this BTE composition the most favourable among the examined types of implants for application in BTE

Antioxidative status of saliva before and after non-surgical periodontal treatment

Introduction. Oxidative stress and antioxidants play an important role in the pathogenesis of inflammatory disease, including chronic periodontitis (CP). Saliva contains enzymatic (glutathione peroxidase - GPx, superoxide dismutase - SOD, etc.) and non-enzymatic (albumin - ALB, uric acid - UA, glutathione, etc.) antioxidants. Objective. The aims of this study were to investigate: a) level of SOD, GPx, UA, ALB and total antioxidative status (TAS) of saliva in CP patients before and after non-surgical treatment, and b) correlations between clinical periodontal parameters and levels of salivary antioxidants. Methods. Saliva was collected from 21 CP patients before and after non-surgical treatment. The condition of periodontium was assessed by plaque index, gingival index, bleeding on probing, probing depth and clinical attachment loss. Level of investigated antioxidants (except GPx) and TAS was determined using colorimetric method and commercial kits. GPx activity was determined using UV method and commercial kits. Results. After the treatment significant increase of UA, ALB, Gpx, TAS was detected (p0.05). A significant correlation was observed between GPx and PI (r=0.575, p=0.008), SOD and GI (r=0.525, p=0.017) before therapy, and SOD and bleeding on probing (BP) (r=0.59, p=0.006), TAS and BP (r=0.453, p=0.045) after therapy. Conclusion. These data suggest that levels of salivary antioxidants generally increase after non-surgical periodontal treatment. Correlation between some clinical periodontal parameters and level of salivary antioxidants was found. [Projekat Ministarstva nauke Republike Srbije, br. 41008