Utjecaj hijaluronske kiseline, kalcijeva hidroksida i dentinskih adheziva na odontoblaste i fibroblaste štakora

The aim of this study was to investigate the effects and efficiency of pulp capping preparations based on hyaluronic acid, calcium hydroxide, and dentin adhesive on the pulp tissue of Sprague-Dawley rats. The rats were killed and extracted teeth sectioned transversely through the pulp. The slices were placed in a RPMI 1640 cell culture medium supplemented with 10 % foetal calf serum. During 14 days of cultivation cultures were treated with preparations that contained hyaluronic acid (Gengigel Prof®), and calcium hydroxide (ApexCal®), or with dentin adhesive (Excite®). Cellularity and viability of fibroblasts and odontoblasts was analysed using a haemocytometer. Hyaluronic acid proved most efficient and the least toxic for direct pulp capping. Even though calcium hydroxide and dentin adhesive demonstrated a higher degree of cytotoxicity, their effects were still acceptable in terms of biocompatibility.Cilj ovog rada bio je istražiti djelovanje preparata na bazi hijaluronske kiseline i kalcijeva hidroksida te dentinskog adheziva na pulpno tkivo Sprague-Dawley štakora u svrhu procjene učinkovitosti navedenih materijala kod direktnog prekrivanja pulpe. Izvađeni zubi transverzalno su podijeljeni kroz pulpu. Naresci su uzgajani u RPMI 1640 staničnom mediju obogaćenom s 10 % fetalnoga telećeg seruma u plastičnim bočicama za staničnu kulturu. Kulture su tijekom 14 dana tretirane preparatima s hijaluronskom kiselinom (Gengigel Prof®), kalcijevim hidroksidom (ApexCal®) i dentinskim adhezivom (Excite®). Nakon 14 dana pristupilo se analizi staničnosti i vijabilnosti s pomoću hemocitometra. Iako su preparati na bazi kalcijeva hidroksida i dentinski adheziv pokazali nešto viši stupanj citotoksičnosti, dobiveni su rezultati u granicama biokompatibilnosti. Primjena preparata na bazi hijaluronske kiseline postigla je najbolje rezultate te se ovaj materijal pokazao najboljim za direktno prekrivanje pulpe između tri ispitivana preparata

Reaction of rat connective tissue to mineral trioxide aggregate and diaket

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to compare the reaction of rat connective tissue to two root-end filling materials: white Mineral Trioxide Aggregate (WMTA) and Diaket.</p> <p>Methods</p> <p>Each of the materials was placed in dentine tubes and implanted subcutaneously in the dorsal connective tissue of 21 Wistar albino rats. Tissue biopsies were collected 7, 30, and 60 days after the implantation procedure. The specimens were processed and stained with hematoxylin and eosin and examined microscopically. After determining inflammatory cell numbers in sections from each specimen, inflammatory reaction scores were defined as follows: 0; no or few inflammatory cells (no reaction), 1; less than 25 cells (mild reaction), 2; 25 to 125 cells, (moderate reaction), and 3; 125 or more cells (severe reaction). Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney tests.</p> <p>Results</p> <p>There were statistically significant differences in the median inflammatory cell numbers throughout the three test periods, with the most severe degree of inflammation observed at the one-week period. Few cases of necrosis were observed with WMTA. Diaket exhibited the most severe degree of inflammation and necrosis. After 30 days, both materials provoked moderate inflammatory reaction. The eight-week period showed the least severe degree of inflammation in all groups.</p> <p>Conclusions</p> <p>It was concluded that WMTA exhibits a more favourable tissue response compared with Diaket which induced more severe inflammatory reaction than WMTA and the control.</p

Do pre‐existing microcracks play a role in the fracture resistance of roots in a laboratory setting?

Aim To investigate a potential cause–effect relationship between dentinal microcracks and fracture resistance of mandibular incisors that had not been endodontically treated. Methodology Sixty mandibular incisors with circular‐shaped canals were selected based on micro‐computed tomographic scans to create a homogeneous sample. The cross‐sectional images of the specimens were screened to identify and quantify the presence of dentinal microcracks. Then, teeth were embedded in polystyrene resin and subjected to axial compressive loading using a universal testing machine. After fracture, the roots were re‐scanned and fractography analysis was performed by inspection of 3D models to verify crack propagation. Spearman’s rank correlation was used to assess the correlation between the number of microcracks and force required to fracture. Results Dentinal microcracks were detected in 79% of the specimens (n = 44). The incidence of microcracks varied between teeth from 6% to 42% of the total slices per sample (average of 14 ± 17%). The number of microcracks per sample varied from 0 to 1605, with an average of 412 ± 484 (median = 221 and IQR 25% = 15/75% = 658). The load at failure values varied from 227 to 924 N, with an average of 560.3 ± 168.1 N (median = 561 and IQR 25% = 458/75% = 694). The Spearman correlation coefficient (rho) equalled 0.065. Conclusions There was no cause–effect relationship between the number of dentinal microcracks and the fracture resistance of nonendodontically treated mandibular incisors. The presence and quantity of microcracks did not make these roots more prone to fracture