Bioactive Dentin Research Articles

Bioactive dentin replacement

Replacement of dentin with a material popularly marketed as Biodentine (Septodont, Saint Maur des Fausses, France), a new tricalcium silicate-based cement, has recently been commercialized and advertised as a bioactive material. Its clinical application and physical properties have been widely described. Biodentine, a new biologically active cement which has dentin-like mechanical properties and can be used as a dentin replacement in the tooth crown and root region. The cement consists mainly of a tri- and dicalcium silicate powder, which is mixed with an aqueous calcium chloride solution. As regards biocompatibility, long- term impermeability, antibacterial properties, induction of hard tissue regeneration, stability, low solubility, non-absorbability and ease of handling, Biodentine fulfils the requirements found in the literature for a material suitable for these purposes. On the basis of the good material properties of Biodentine, this cement is an interesting alternative to the conventional materials which were hitherto recommended. Biodentine can therefore confer advantages in day-to-day practice and with correct diagnosis contribute to the long-term maintenance of the vitality of the dental pulp and to the retention of teeth. However, little scientific data is available at present.

Single-visit Apexification using Biodentin

ABSTRACT Trauma to the tooth mainly results in pulpal injury, and these injuries during formative stage can result in incomplete root formation. This can result in failure in closure of root apex, resulting in wide open apex. This causes problem for the conventional root canal therapy as there is no apical stop against which the obturation material can be condensed. The management of a nonvital tooth with open apex is aimed at creation of an apical barrier. The newly introduced bioactive dentin substitute commercially available as biodentin is a promising material. It is a cement for stimulating hard tissue formation, i.e., the formation of reactive or reparative (tertiary) dentin. This case report describes the management of a traumatized permanent maxillary central incisor with an open apex. How to cite this article Nazar F, Nair KR, Praveena G, Anilkumar A, Rajendran R. Single-visit Apexification using Biodentin. Cons Dent Endod J 2017;2(1):40-42.

Dissolution of bio-active dentine matrix components by mineral trioxide aggregate

Objectives To analyze the soluble components of setting and set mineral trioxide aggregate (MTA), assess the abilities of two varieties of MTA and Ca(OH) 2 solutions to solubilise dentine matrix proteins (DMPs) and determine if these extracts contain signalling molecules important to pulpal repair and regeneration. Methods The metallic ion composition of solutions of white and grey MTA (pH 11.7), 0.02 M Ca(OH) 2 (pH 11.9) and 10% EDTA (pH 7.2) was determined using atomic absorption spectroscopy. Extracellular dentine matrix components from powdered human dentine were extracted using all solutions over 14 days. Extracts were analysed for concentrations of non-collagenous proteins (NCPs) and glycosaminoglycans (GAGs), and protein profiles were examined using 1D-polyacrylamide gel electrophoresis (1D-PAGE). ELISAs for TGF-β1 and adrenomedullin (ADM) were also performed. Results Aluminium, calcium, potassium, and sodium ions were detected in both white and grey MTA solutions. MTA and Ca(OH) 2 solutions liberated similar amounts of GAGs and NCPs although yields were considerably lower than those obtained using the EDTA solution. 1D-PAGE analysis demonstrated differences in protein profiles solubilised from dentine for all solutions. All extracts contained TGF-β1 and ADM, EDTA solution liberated significantly greater amounts of TGF-β1, and Ca(OH) 2 and grey MTA solutions released more ADM. Conclusions These data imply that when placed clinically soluble components of set and setting MTA may release dentine matrix components that potentially influence cellular events for dentine repair and regeneration.

Reactionary dentinogenesis after applying restorative materials and bioactive dentin matrix molecules as liners in deep cavities prepared in nonhuman primate teeth

The aim of this in vivo study was to evaluate the response of the pulp-dentin complex following application of resin-modified glass-ionomer cement, calcium hydroxide hard-setting cement and EDTA-soluble preparation of dentine matrix proteins (ESDP) in deep cavities prepared in non-human primate teeth. Eighteen deep Class V buccal cavities were prepared in premolars of four capuccin monkeys. In Groups 1 and 2, the cavity floor was lined with ESDP or a resin-modified glass-ionomer cement (Vitrebond - 3M ESPE), respectively. In Group 3 (control), the cavity was lined with a hard setting calcium hydroxide cement (Dycal - Dentsply). The cavities were subsequently filled with amalgam. After 6 months, the animals were sacrificed and the teeth were prepared for microscopic assessment. Six-micron thick serial sections were stained with H/E, Masson's trichrome and Brown & Brenn techniques. No inflammatory pulpal response was observed for all experimental and control Groups. However, the amount of reactionary dentin deposition differed between groups in the rank order ESDP (Group 1) > calcium hydroxide (Group 3) > resin-modified glass-ionomer (Group 2). These differences were statistically significant. All materials were biocompatible when applied in deep cavities. ESDP stimulated higher deposition of reactionary dentin matrix than Vitrebond and Dycal.

The effect of calcium hydroxide on solubilisation of bio-active dentine matrix components

Calcium hydroxide (Ca(OH) 2) has been used extensively to induce dentine regeneration through formation of dentine bridges at sites of pulp exposure after dental tissue injury, however, the biological processes underpinning these events are unclear. We hypothesise that growth factors and other bio-active molecules, sequestered within dentine matrix, may be released by the action of Ca(OH) 2 and signal gene expression in pulp cells, which mediates the changes in cell behaviour observed during regeneration. Powdered sound, human dentine samples were extracted with either 0.02 m Ca(OH) 2, pH 11.7 or 10% EDTA, pH 7.2 ( a control known extractant of bio-active and other ECM molecules from dentine) over a 14-day period. Extracts were compared for non-collagenous protein (NCP) and glycosaminoglycan (GAG) content using dye binding assays and protein compositions were analysed by 1D-polyacrylamide gel electrophoresis (1D-PAGE) and TGF- β1 ELISA. The effects of extracts on TGF- β1, Collagen-1 α and Nestin gene expression were analysed using semi-quantitative RT-PCR in the dental MDPC-23, OD-21 and fibroblastic Swiss 3T3 cell lines following 24 h of exposure. Ca(OH) 2 solubilised NCPs and GAGs from the dentine ECM, although with a lower yield than the EDTA solution and with different kinetics. 1D-PAGE analysis demonstrated some differences in profiles for proteins solubilised from dentine by Ca(OH) 2 and EDTA. Both solutions released TGF- β1 from the dentine with higher concentrations present in the EDTA (1.395±0.036 ng/mg) versus the Ca(OH) 2 (0.364±0.012 ng/mg) extract. Notably, both extracts induced similar gene expression profiles in all cell lines. These data provide a rational explanation for the action of Ca(OH) 2 during pulp capping in which the cellular activities involved in dentine bridge formation may be mediated through release of growth factors and other bio-active molecules from the dentine by Ca(OH) 2.

Interaction between bioactive glasses and human dentin.

This study explores the interaction between bioactive glasses and dentin from extracted human teeth in simulated oral conditions. Bioactive glasses in the Na(2)O-CaO-P(2)O(5)-SiO(2) and MgO-CaO-P(2)O(5)-SiO(2) systems were prepared as polished disks. Teeth were prepared by grinding to expose dentin and etching with phosphoric acid. A layer of saliva was placed between the two, and the pair was secured with an elastic band and immersed in saliva at 37 degrees C for 5, 21 or 42 days. The bioactive glasses adhered to dentin, while controls showed no such interaction. A continuous interface between the bioactive glass and dentin was imaged using cryogenic-scanning electron microscopy (SEM). However, after alcohol dehydration and critical point drying, fracture occurred due to stresses from dentin shrinkage. SEM investigations showed a microstructurally different material at the fractured interface. Chemical analyses revealed that ions from the glass penetrated into the dentin and that the surface of the glass in contact with the dentin was modified. Microdiffractometry showed the presence of apatite at the interface. Bonding appears to be due to an affinity of collagen for the glass surface and chemical interaction between the dentin and glass, leading to apatite formation at the interface.