Kinetics of apatite formation on a calcium-silicate cement for root-end filling during ageing in physiological-like phosphate solutions

Laboratory of Biomaterials and Oral Pathology, Department of Odontostomatological Science, Endodontic Clinical Section, University of Bologna, Italy.
Clinical Oral Investigations (Impact Factor: 2.35). 11/2009; 14(6):659-68. DOI: 10.1007/s00784-009-0356-3
Source: PubMed

ABSTRACT The bioactivity of calcium silicate mineral trioxide aggregate (MTA) cements has been attributed to their ability to produce apatite in presence of phosphate-containing fluids. This study evaluated surface morphology and chemical transformations of an experimental accelerated calcium-silicate cement as a function of soaking time in different phosphate-containing solutions. Cement discs were immersed in Dulbecco's phosphate-buffered saline (DPBS) or Hank's balanced salt solution (HBSS) for different times (1-180 days) and analysed by scanning electron microscopy connected with an energy dispersive X-ray analysis (SEM-EDX) and micro-Raman spectroscopy. SEM-EDX revealed Ca and P peaks after 14 days in DPBS. A thin Ca- and P-rich crystalline coating layer was detected after 60 days. A thicker multilayered coating was observed after 180 days. Micro-Raman disclosed the 965-cm(-1) phosphate band at 7 days only on samples stored in DPBS and later the 590- and 435-cm(-1) phosphate bands. After 60-180 days, a layer approximately 200-900 μm thick formed displaying the bands of carbonated apatite (at 1,077, 965, 590, 435 cm(-1)) and calcite (at 1,088, 713, 280 cm(-1)). On HBSS-soaked, only calcite bands were observed until 90 days, and just after 180 days, a thin apatite-calcite layer appeared. Micro-Raman and SEM-EDX demonstrated the mineralization induction capacity of calcium-silicate cements (MTAs and Portland cements) with the formation of apatite after 7 days in DPBS. Longer time is necessary to observe bioactivity when cements are immersed in HBSS.

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Available from: Maria Giovanna Gandolfi, Sep 29, 2015
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    • "[8] The sealing ability of MTA has been reported to be superior to that of amalgam, IRM and Super EBA. [9] [10] [11] MTA has bioactive properties, can release calcium and expands during setting [12]. It induces proliferation, and not apoptosis, of pulp cells in vitro. "
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    ABSTRACT: Insolubility is an important criterion for an ideal root-end filling material to both prevent any microleakage between the root canal and the periradicular space and provide sealing ability. Many recent studies have shown that mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) have acceptable sealing ability. The purpose of this in vitro study was to evaluate the solubility of these root-end filling materials. Forty stainless steel ring moulds with an internal diameter of 10±1 mm and a height of 2±0.1 mm were selected. Samples of MTA and CEM were mixed according to the manufacturer's instructions and inserted into the moulds. The specimens were divided into 4 experimental groups and kept in synthetic tissue fluid (STF) for 2 different time periods (7 and 28 days). The control group contained 8 empty rings. The moulds' weights were recorded before and after immersion in STF. The changes in the weight of the samples were measured and compared using a two- way ANOVA test at a significance level of 5%. Specimens were evaluated with scanning electron microscopy (SEM) at a magnification of 500×. There was no significant difference in weight changes between MTA and CEM samples (p> 0.05). MTA and CEM have similar solubility in STF in different time periods.
    09/2015; 16(3):189-94.
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    • "Sodium fluoride was introduced into the formulation of MTA cements to improve their biological behavior due to its good biological activity on osteoblast cells.[31] It has been demonstrated that the presence of fluoride in MTA cements improves the expansion of MTA cements[3134] and that the presence of phosphorous improves the ability to form apatite.[32] Alpha-TCP improves the apatite-formation ability of calcium silicate hydraulic cement soaked in phosphate solutions.[33] "
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    ABSTRACT: Objective: This study was aimed to evaluate and to compare the push-out bond strength of different brands of mineral trioxide aggregate (MTA) with a calcium enriched mixture cement (CEM). Materials and Methods: Fifteen extracted, single-rooted human teeth were used. The middle-third of the roots were sliced perpendicular to the long axis into 1.00 ± 0.05 mm thick serial slices (15 root × 4 slice = 60 specimen). The specimens were then divided into three groups (n = 20). The standardized root discs were filled with white CEM, ProRoot MTA, MTA-Angelus and wrapped in a serum-soaked gauze. After 3 days at relative humidity, the push-out bond strengths were measured with a universal testing machine. Data were analyzed using one-way analysis of variance and post hoc Tukey tests. Results: The mean push-out bond strength value of the ProRoot MTA group (12.7 ± 2.5 MPa) was the highest and statistically significant difference was recorded between ProRoot MTA and other groups (P < 0.001). There was no significant difference between the mean bond strength of CEM cement (4.6 ± 1.1 MPa) and MTA-Angelus (4.5 ± 1.5 MPa) (P = 0.982). Conclusion: The push-out bond strength of MTA was changed with the brands and ProRoot MTA had the highest push-out bond strength.
    European journal of dentistry 07/2014; 8(3):348-52. DOI:10.4103/1305-7456.137646
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    • "Conventional MTA cements showed some clinical limitation when used as endodontic materials due to their poor handling [24] and extended setting time [9,18–23,25]. The composition of MTA-based cements can be properly modified to improve physicochemical properties as well as handling characteristics, to reduce the setting time [9] [26] [27] and the solubility by including a resin, as previously demonstrated by Gandolfi et al. [28] or the apatite-forming ability [11] [13] [29] [30]. It has been recently demonstrated that MTA cements doped with alpha-tricalcium phosphate support the survival and differentiation of human orofacial bone mesenchymal stem cells [31] and that calcium phosphate have a stimulatory effect on cementoblasts [32]. "
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    ABSTRACT: The aim of this study was to evaluate the calcium release, pH, flow, solubility, water absorption, setting and working time of three experimental root canal sealers based on mineral trioxide aggregate (MTA) and two forms of calcium phosphates (CaP). The materials were composed of a base and a catalyst pastes mixed in a 1:1. The base paste was made by 60% bismuth oxide and 40% butyl ethylene glycol disalicylate. Three different catalyst pastes were formulated containing 60% MTA or 40% MTA+20% CaP (hydroxyapatite HA or dibasic calcium phosphate dehydrate DCPD), 39% Resimpol 8% and 1% titanium dioxide. MTA Fillapex was used as control. The release of calcium and hydroxyl ions, solubility and water absorption were measured on regular intervals for 28 days. The working time and flow were tested according to ISO 6876:2001 and the setting time according to ASTM C266. The data were analyzed using 1-way ANOVA with Tukey's test (p<.01). All the cements showed basifying activity and released calcium ions. MTA Fillapex showed the highest values of flow (p<.01) and working/setting times (p<.01) and the smallest values of solubility (p<.01) and water absorption (p<.01). All experimental materials showed satisfactory physical-chemical properties to be used as endodontic sealers in clinical practice.
    Dental materials: official publication of the Academy of Dental Materials 10/2013; 29(12). DOI:10.1016/ · 3.77 Impact Factor
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