Calcium Silicate Sealers Research Articles

Cytocompatibility, bioactivity, and antimicrobial activity of experimental calcium-silicate sealer

Cytocompatibility, bioactivity, and antimicrobial activity of experimental calcium-silicate sealer

Properties of BioRoot RCS, a tricalcium silicate endodontic sealer modified with povidone and polycarboxylate.

To evaluate the chemical and physical properties of a tricalcium silicate root canal sealer containing povidone and polycarboxylate (BioRoot RCS), a calcium silicate MTA-based sealer containing a salicylate resin (MTA Fillapex), a traditional eugenol-containing sealer (Pulp Canal Sealer) and an epoxy resin-based root canal sealer (AH Plus). Calcium release, pH, setting time, water sorption, volume of open pores, volume of impervious portion, apparent porosity and weight loss were measured. The ability to nucleate calcium phosphates (CaP) after ageing 28days in a simulated body fluid was evaluated using ESEM-EDX and micro-Raman spectroscopy. Data were statistically analysed (P=0.05) using one-way anova (setting time, radiopacity, solubility, water sorption, porosity) or two-way anova (ion release tests). BioRoot RCS had a final setting time of 300min and adequate radiopacity (5.2mm Al). It demonstrated the highest (P<0.05) and more prolonged ability to release calcium ions (721ppm at 3h) and to increase the pH (11-12) (P<0.05); B-type carbonated apatite deposits were found on aged BioRoot RCS (biointeractivity-related CaP-forming ability). A final setting time of 270min and good calcium release (17.4ppm at 3h) were measured for MTA Fillapex; apatite deposits were present on aged samples. No calcium release and no alkalizing activity were measured for Pulp Canal Sealer and AH Plus; no CaP nucleation was detected on aged Pulp Canal Sealer, and some apatite deposits were found on aged AH Plus (chemi/physisorption-related CaP-deposition). Higher and significantly different (P<0.05) porosity, water sorption and solubility were measured for the two calcium silicate sealers, especially for BioRoot RCS. BioRoot RCS had bioactivity with calcium release, strong alkalizing activity and apatite-forming ability, and adequate radiopacity.

Synchrotron-based Phase Contrast-enhanced Micro–Computed Tomography Reveals Delaminations and Material Tearing in Water-expandable Root Fillings Ex Vivo

IntroductionThis study evaluated the integrity of calcium silicate sealer–based fillings made with hygro-expandable cones (HEC) that are commercially known as CPoint or Smartpoint. MethodsFourteen human canines were prepared according to a standardized, conventional endodontic treatment protocol and filled with the HEC/calcium silicate sealer. Three-dimensional imaging was performed with laboratory micro–computed tomography (μCT) at its highest resolution and was compared with synchrotron phase contrast-enhanced μCT (PCE-CT) scans of the treatment extending 1–7 mm from the apex. Conventional destructive optical microscopy validated observations by comparison with virtual slices in the tomographic data. ResultsConventional laboratory μCT at 10-μm resolution did not reveal the existing voids and defects within the root canal fillings. PCE-CT revealed elongated interfacial delamination localized mainly at the HEC-sealer interface forming extended through-and-through gaps along the root canal filling. ConclusionsEndodontic studies that use conventional laboratory μCT may underestimate thin defects and delamination within root canal fillings made with HEC because of limited resolution and contrast of laboratory-based broad-spectrum low intensity x-ray sources. These limitations favor use of high-brilliance, monochromatic synchrotron-based PCE-CT to reveal the important micrometer details within large (millimeter sized) samples. PCE-CT revealed the existence of a range of significant structural defects in recently placed HEC fillings, confirmed by optical microscopy after physical sectioning. Substantial delamination spanning 20%–40% of the circumferential interface as well as other structural defects were identified within root canal fillings made of HEC and calcium silicate sealer.

The effect of root dentin conditioning protocols on the push-out bond strength of three calcium silicate sealers

Objectives: To compare the effects of irrigation protocols on the push-out bond strength of calcium silicate materials at two different time periods (7-days and 3-months). Materials and methods: Root canals (n=300) were irrigated with one of the following (n=60): group 1 (3% NaOCl–17% EDTA); group 2 (17% EDTA–3% NaOCl); group 3 (1:1 mixture of 6% NaOCl and 18% etidronic acid); group 4 (3% NaOCl–QMix 2in1); group 5 (3% NaOCl–2% chlorhexidine). Specimens were subdivided into three subgroups (n=20): A, Endosequence BC sealer [EBC]; B, MTA Plus [MTA-P]; C, Tech Biosealer Endo [TECH]. Specimens were suspended in phosphate buffered saline [PBS] for 7 days or 3 months (n=10 per sealer). Push-out bond strength was measured and data were analyzed (P=0.05). Results: MTA-P: showed the highest bond strength at both time periods, when NaOCl+EA was used as an irrigant. This was not significantly different from the strength produced when NaOCl–QMix was used for 7 days (P>0.05). There was no significant difference between the bond strengths of the three materials when irrigated with group 1, 2 or 5 (P>0.05), but these groups showed significantly lower bond strengths than groups 3 and 4 (P<0.05). While the bond strength of EBC and MTA-P in specimens irrigated with groups 3 and 4 improved significantly with time [P<0.05], this was not true for TECH. Conclusions: Push-out bond strength of calcium silicate cements was differentially influenced by irrigation protocol and time. MTA Plus showed the highest bond strength at both time periods, when root canals were irrigated with NaOCl+EA. The bond strength of Tech Biosealer Endo did not improve with time immaterial of the irrigation protocols.

The Effect of Obturation Technique on the Push-out Bond Strength of Calcium Silicate Sealers

IntroductionCalcium silicate–based sealers are known to have excellent sealing ability and bioactivities. They are typically recommended to be used in a single-cone (SC) technique. No studies have evaluated the effects of the thermoplastic obturation technique on the dentin interface of these sealers. The purpose of this study was to evaluate the push-out bond strengths of MTA Plus Sealer (Avalon Biomed Inc, Bradenton, FL) and EndoSequence BC Sealer (BC; Brasseler USA, Savannah, GA) when they were used in a thermoplastic technique. MethodsFifty single-rooted human extracted teeth were randomly divided into 5 groups (n = 10), instrumented, and obturated with the SC technique or continuous wave (CW) technique: group 1, BC-SC; group 2, BC-CW; group 3, MTA Plus–SC; group 4, MTA Plus–CW; and group 5, AH Plus (Dentsply DeTrey, Konstanz, Germany)–CW. The roots were sectioned into 1.0-mm-thick slices, and bond strengths were measured using a standardized push-out test. The mode of failure was determined by visual inspection under magnification. ResultsThe MTA Plus–CW had statistically significant lower bond strengths than all other groups. The BC-SC group had statistically higher bond strengths than the MTA Plus–SC and AH Plus–CW groups. No significant differences were seen among the other groups. Modes of failure were predominately cohesive or mixed except for group 4 (ie, MTA Plus–CW) in which nearly half the specimens had no visible sealer. ConclusionsBC and MTA Plus sealer showed favorable bond strengths when used in an SC technique. The CW obturation technique decreased the bond strengths of these sealers.

Solubility, pH Changes and Releasing Elements of Different Bioceramic and Mineral Trioxide Aggregate Root Canal Sealers Comparative Study

Introduction: Bioceramic technology has been introduced recently in endodontics to benefit from the formation of hydroxyapatite during the setting reaction in the presence of tissue fluid and establish a chemical bond at the dentin interface. Objectives: To evaluate some of physiochemical properties of new different Bioceramic (iRoot-SP, EndoSequence, Smartpastebio) versus mineral trioxide aggregate (MTA-Fillapex) root canal sealers. Adseal and ActiV-GP sealers were used as control. Methods: Standard discs (10 for each) were prepared and immersed in 20 ml deionized water. After 1, 7, 14 and 28 days, solubility, pH changes and released elements were calculated and statistically analyzed with ANOVA test. Results: A significantly greater solubility and higher alkalinity were displayed by the tested sealers (in descending order) Smartpastebio, iRoot-SP, EndoSequence and MTA-Fillapex (P<0.05). Their solubility exceeded the acceptable limit (3%). Their maximum alkaline pH was exhibited after 7 days. Adseal and ActiV-GP exhibited initial neutral and acidic pH respectively. Finally both had neutral pH. EndoSequence exhibited the significantly greatest calcium release followed by iRoot-SP, Smartpastebio and MTA-Fillapex, whereas, ActiV-GP and Adseal exhibited the significantly lowest values (P<0.05). There was no silicon released from iRoot-SP, Smartpastebio and MTA-Fillapex. ActiV-GP exhibited the greatest silicon, aluminum and iron release. The greatest phosphorous, manganese and magnesium content was obtained by Adseal, MTA-Fillapex and EndoSequence respectively. Conclusion: Under the condition of this study, the prolonged alkalinity of calcium silicate sealers was synchronized with their ongoing solubility. The higher calcium ions released indicated strong alkalinity. The inequality in aluminum, iron, manganese and magnesium released by the tested sealers may expect the variance in their behaviors.

MTA and F‐doped MTA cements used as sealers with warm gutta‐percha. Long‐term study of sealing ability

To evaluate the long-term sealing ability (up to 6 months) of two experimental calcium silicate MTA cements used as root canal sealers in association with warm gutta-percha. Calcium silicate (MTA) and calcium-fluoro-silicate powders were prepared. Sodium fluoride was included in FMTA (Fluoride-doped Mineral Trioxide Aggregate) as an expansive and retardant agent. Single-rooted teeth were instrumented with NiTi rotary instruments, filled with warm gutta-percha in association with one of the experimental sealers or with AH Plus as a control (n = 20 for each sealer) and stored at 37 °C. Sealing was assessed at 24, 48 h, 1, 2 weeks and 1, 3, 6 months by a fluid filtration method. Scanning electron microscopy with energy dispersive analysis (SEM/EDX) was used to study the dentine/sealer interface of roots stored for 6 months and the surface of cement disks stored for 24 h. All sealers revealed a statistically significant reduction (P < 0.05) in fluid filtration after the first 2 weeks. No statistically significant differences were observed between FMTA and AH Plus at all analysis times. At short times (24, 48-h), no statistically significant differences were found between the experimental cements and AH Plus. At long-term evaluations (1, 3, 6 months), FMTA and AH Plus sealed significantly better (P < 0.05) than MTA. FMTA was associated with lower fluid filtration rates, and the seal was stable from 48 h to 6 months, thus proving the most effective material. Scanning electron microscopy with energy dispersive analysis of root sections filled with calcium silicate sealers revealed the formation of a blend layer of gutta-percha and cement consequent to the warm gutta-percha condensation technique. Scanning electron microscopy with energy dispersive analysis of 24-h-stored disks identified a Ca-rich coating on the outer surface consisting of globular particles (calcium hydroxide and calcium carbonate), and a deeper internal Ca- and Si-rich region consisting of needle-like ettringite crystals and round formations of calcium silicate hydrate gel. Fluoride-doped MTA demonstrated stable sealing during a period of up to 6 months and significantly better than conventional calcium silicate MTA cements and comparable to AH Plus. The study supports the suitability of calcium silicate MTA cements as sealers in association with warm gutta-percha for root filling.