The Application of 29Si NMR Spectroscopy to the Analysis of Calcium Silicate-Based Cement using Biodentine™ as an Example

Abstract

Biodentine is one of the most successful and widely studied among the second generation of calcium silicate-based endodontic cements. Despite its popularity, the setting reactions of this cement system are not currently well understood. In particular, very little is known about the formation and structure of the major calcium silicate hydrate (C-S-H) gel phase, as it is difficult to obtain information on this poorly crystalline material by the traditional techniques of powder X-ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR). In this study, the hydration reactions of Biodentine are monitored by XRD, FTIR, isothermal conduction calorimetry and, for the first time, 29Si magic angle spinning nuclear magnetic resonance spectroscopy (29Si MAS NMR) is used to investigate the structures of the anhydrous calcium silicate phases and the early C-S-H gel product. XRD analysis indicated that the anhydrous powder comprises 73.8 wt% triclinic tricalcium silicate, 4.45 wt% monoclinic β-dicalcium silicate, 16.6 wt% calcite and 5.15 wt% zirconium oxide. Calorimetry confirmed that the induction period for hydration is short, and that the setting reactions are rapid with a maximum heat evolution of 28.4 mW g−1 at 42 min. A progressive shift in the FTIR peak maximum from 905 to 995 cm−1 for the O-Si-O stretching vibrations accompanies the formation of the C-S-H gel during 1 week. The extent of hydration was determined by 29Si MAS NMR to be 87.0%, 88.8% and 93.7% at 6 h, 1 day and 1 week, respectively, which is significantly higher than that of MTA. The mean silicate chain length (MCL) of the C-S-H gel was also estimated by this technique to be 3.7 at 6 h and 1 day, and to have increased to 4.1 after 1 week. The rapid hydration kinetics of Biodentine, arising from the predominance of the tricalcium silicate phase, small particle size, and ‘filler effect’ of calcite and zirconium oxide, is a favorable characteristic of an endodontic cement, and the high values of MCL are thought to promote the durability of the cement matrix.

Biocompatibility of Biodentine™ ® with Periodontal Ligament Stem Cells: In Vitro Study

“…Thus, this mixture makes it a better filling material, when compared to others such as Portland and MTA cement [8]. The hydration kinetics of these components in Biodentine™ has improved its physicochemical properties such as the mechanical strength, speed of curing, the initial and the final setting time [8,12,13]. Biodentine™ has been considered as a promising pulp capping material that can be used in the field of restorative dentistry to replace the dentine.…”

Cytotoxicity and Mineralization Potential of Four Calcium Silicate-Based Cements on Human Gingiva-Derived Stem Cells

“…Biodentine (Septodont, Saint-Maur-des-Fossés, France) is composed mostly of tricalcium silicate, zirconium oxide, and calcium carbonate powder, which are mixed with a supplied solution that includes calcium chloride [12,13]. The reduced setting time compared to MTA is achieved by diminishing the particle size and adding calcium chloride to expedite the reactions [13][14][15]. The substitution of bismuth oxide with zirconium oxide may also play a role in reduced setting time, because this component has been reported to expedite the primary hydration reaction [13].…”

“…The reduced setting time compared to MTA is achieved by diminishing the particle size and adding calcium chloride to expedite the reactions [13][14][15]. The substitution of bismuth oxide with zirconium oxide may also play a role in reduced setting time, because this component has been reported to expedite the primary hydration reaction [13]. Previous studies of this material's effects on dental pulp stem cells demonstrated its biocompatible ability, odontoblast differentiation ability, and mineralization potential [12,16].…”

The advantages and disadvantages of biodentine: Satisfactory mechanical properties and radiopacity not meeting ISO standard

“…Tremendous progress has been accomplished in last several decades in the field of materials science 1,2,3 . In dentistry, the concept of using inert materials for tissue repair has been replaced with strategy to find bioactive materials which positively interact with human tissues 4,5 .…”

“…In order to meet clinical requirements of CSC based dental material, a radiopacifier has to be added to its composition to allow cement's visibility on radiographs 2,8,9 . However, finding an ideal balance between the ratio of radiopacifier and cement powder remains a challenge of the dental and engineering community 3,10,11 . When choosing a proper radiopacifier for cement fabrication several aspects should be taken into consideration.…”