Silicate Cement Research Articles

Porous silicate cement membrane: Unraveling the effect of triethanolamine on ice crystal changing, pore structure, and performance

Triethanolamine (TEA) has been broadly used as the organic amine conditioning agent to modify the workability of cement-based materials. However, the effect of TEA on the structure and property of porous silicate cement membranes has not been reported. In this paper, TEA was applied to study its effect on parameters of porous silicate cement membranes based on the preparation method combining freeze casting and heat-dry curing, because it is easy to form complexes with cement particles. The effect and acting mechanism of TEA on porous silicate cement membranes were researched using a series of characterizations and molecular dynamics (MD) simulation. Results showed that TEA significantly improved the performance of porous silicate cement membranes. The addition of TEA changed the pore morphology of porous silicate cement membranes from lamellar structures to cellular structures, with mesoporous size distribution focusing on 2.5–4.5 nm at TEA doping ratio of 0.16 wt%. The oil-water separation performance could reach up to 99.6 %. Through comprehensive comparison, the porous silicate cement membrane with 1.0 wt% TEA showed better holistic preponderance of oil-water separation and permeation flux. Quantum chemistry calculation and MD simulation were used to briefly explain the influence of TEA on phase transformation. MD showed that adding TEA changed the morphology and structure of ice crystals. The percentage of the Ih structure significantly increased from 53 % to 86 % after adding TEA. This study might expand the application of TEA in other aspects and enlighten relevant workers in new experimental designs.

Fracture Resistance of Simulated Immature Teeth Filled with Three Types of Calcium Silicate Cement after Intracanal Medication with Ca(OH)2: An Ex Vivo Study.

The aim of this study was to evaluate the 1-day fracture resistance of simulated immature teeth with an apical plug with ProRoot MTA, MTA Angelus, and RetroMTA after calcium hydroxide intracanal medication. Sixty extracted, single-rooted human mandibular premolars were randomly divided into six groups of 10 teeth each. Firstly, to standardize the 9 mm root length, the crowns were cut off at and 9 mm below the cementoenamel junction transversely. Simulations for immature apices were carried out by using No. 1-6 Peeso reamers to pass through the apex to obtain a diameter of 1.7 mm at the apical opening. One group served as a negative control without any treatment, while the other groups received 30 days of calcium hydroxide intracanal medication. Four groups were plugs with 4 mm of ProRoot MTA, MTA Angelus, RetroMTA, and gutta-percha, respectively. The last one was served as a positive control group without filling inside. After 1 day of incubation, specimens were vertically loaded in a universal testing machine at a crosshead speed of 1 mm/min until fracture occurred. The peak load to fracture (Newton) and fracture pattern were recorded. A one-way analysis of variance (ANOVA) followed by Tukey's HSD test was used for data analysis. The highest mean load to fracture was shown in the negative control group (543.33 ± 37.17 N), followed by ProRoot MTA (432.82 ± 68.06 N), MTA Angelus (396.92 ± 59.93 N), RetroMTA (389.08 ± 56.25 N), and gutta-percha (283.28 ± 43.40 N), and the lowest belonged to the positive control group (239.98 ± 27.19 N). The significant differences were found between both the control and experimental groups with an apical plug with calcium silicate cement (p < 0.05). There were no significant differences among those three apical plugs (p > 0.05). Apical plugs with ProRoot MTA, MTA Angelus, and RetroMTA had an immediate strengthening effect on simulated immature teeth after calcium hydroxide intracanal medication had been used.

Optimization of Ratio and Hydration Mechanism of Titanium-Extracted Residual Slag-Based Filling Cementitious Materials

Using metallurgical solid waste Titanium-extracted Residual Slag (TRS) as mine-filling cementitious material is crucial to reduce the filling cost and promote the utilization of solid waste resources. In this paper, taking the strength of the backfill at different curing ages as the response target, the Design-expert mixing design was used to optimize the proportioning experiment of titanium-extracted residual slag, titanium gypsum, silicate cement, and total tailings, to analyze the interactions and influences of the materials on the strength of the backfill, and to analyze the hydration mechanism of the titanium-extracted residual slag-based filling cementitious materials under the optimal proportioning. The results show that: (1) the order of the sensitivity of each component to the strength of backfill is: composite activator &gt; cement &gt; titanium gypsum &gt; titanium-extracted residual slag, and there are different degrees of interaction between them; (2) the optimal ratio of titanium-extracted residual slag-based filling cementitious materials is TRS:titanium gypsum:cement:composite activator = 55:25:17:3; (3) early strength formation of backfill is mainly related to its hydration products ettringite and C-S-H, the rapid nucleation and cross-growth of ettringite in the early stage forms an effective physical filling effect, which is the main reason for the formation of high early strength, and the later strength of backfill benefited from the continuous accumulation of C-S-H encapsulation and bonding, which further densified its internal structure; (4) the use of titanium-extracted residual slag-based filling cementitious materials contributes to safe, green, and economic mining.

Insights on the effects of carbonates and phosphates on the hydration of magnesia (alumino-)silicate cements

Cements based on magnesium oxide (MgO) and reactive (alumino-)silicates (xSiO2-yAl2O3) have drawn increasing attention owing to their potential to be produced using raw materials with low CO2 emissions. This study examines how the phase assemblages and compressive strengths of magnesia (alumino-)silicate cements are influenced by the addition of sodium hexametaphosphate (NaHMP) and sodium carbonate (Na2CO3). Cement paste samples with a Mg/Si molar ratio of 1.5 and Al/Si molar ratios of 0 and 1.0 were prepared using microsilica (SF) and metakaolin (MK), respectively, and investigated using SEM, TGA, XRD, and 29Si, 27Al, 31P, and 13C MAS NMR. The results showed that the addition of NaHMP and sodium carbonate enhanced the reactivity of the raw materials in the Al-free MgO-SF systems, with magnesium silicate hydrate (M-S-H) being the primary hydrated phase. After 91 days, the degrees of reaction of microsilica were ∼86% and 96% for systems containing 0 and 2.5 wt % Na2CO3, respectively. In contrast, the reactivity of metakaolin in the Al-containing MgO-MK systems was limited to ∼53%, irrespective of Na2CO3 addition, likely due to the excess sodium hexametaphosphate covering the surface of MK. Here, the main reaction products were magnesium aluminosilicate hydrate (M-A-S-H) and hydrotalcite (Mg6Al2CO3(OH)16·4(H2O))-like phases. Despite the MgO-SF systems displaying higher degree of reaction than the MgO-MK systems, the latter exhibited higher compressive strength. Sodium carbonate increased the compressive strength of the MgO-SF systems but decreased that of the MgO-MK systems. Thermodynamic modelling was also carried out and the results generally agreed with the phase formation observed with XRD and solid-state NMR.

ANALISYS OF TEMPERATURE CHANGES DURING LIGHT POLYMERIZATION OF RESIN MODIFIED CALCIUM SILICATE CEMENTS

Resin-modified calcium silicate cements belong to the fourth generation. This type of material is a combination of calcium silicates and resin. They are hardened by two types of reactions: light polymerization and hydration. Ð arameters related to temperature increases during light polymerization were analyzed. The main factors affecting the amount of generated heat are the type of light sources (LS), the light intensity of LS, the position of LS, the distance between the material surface and LS, the composition and transmission properties of hybrid material, curing time, remaining dentin thickness and the thickness of the layer of hybrid CSCs. Different methods of measuring temperature changes are criticall discussed.

Effects of vehicles on the physical properties and biocompatibility of premixed calcium silicate cements.

Premixed calcium silicate cements (pCSCs) contain vehicles which endow fluidity and viscosity to CSCs. This study aimed to investigate the effects of three vehicles, namely, polyethylene glycol (PEG), propylene glycol (PG), and dimethyl sulfoxide (DMSO), on the physicochemical properties and biocompatibility of pCSCs. The setting time, solubility, expansion rate, and mechanical strength of the pCSCs were evaluated, and the formation of calcium phosphate precipitates was assessed in phosphate-buffered saline (PBS). The effects of pCSC extracts on the osteogenic differentiation of mesenchymal stem cells (MSCs) were investigated. Finally, the tissue compatibility of pCSCs in rat femurs was observed. CSC containing PEG (CSC-PEG) exhibited higher solubility and setting time, and CSC-DMSO showed the highest expansion rate and mechanical strength. All pCSCs generated calcium phosphate precipitates. The extract of CSC-PG induced the highest expressions of osteogenic markers along with the greatest calcium deposites. When implanted in rat femurs, CSC-PEG was absorbed considerably, whereas CSC-PG remained relatively unaltered inside the femur.

Comparative Evaluation of a New Tricalcium Silicate Cement With Calcium Hydroxide as Direct Pulp Capping Agents: A Clinical Study.

Background and objectives Direct pulp capping (dPC) is a therapeutic process that involves the application of a protective chemical to an exposed pulp with the intent to facilitate the restoration and preservation of its vitality and function. Despite numerous proposed solutions, researchers have yet to find a dependable, non-absorbable bioactive pulp capping substance that constantly activates cellular healing processes, consequently preserving pulpal vitality over an extended period of time. The objective of this study was to assess and contrast the efficacy of a novel tricalcium silicate cement and calcium hydroxide in preserving the long-term health of the dental pulp following dPC using clinical and radiographic observations. Materials and methods A total of 60 individuals with symptoms of reversible pulpitis associated with deep carious lesions were chosen for dPC in the study. Two groups comprising 30 patients each underwent dPC using the novel tricalcium silicate cement (experimental group) and calcium hydroxide (control group) out of the total number of patients. A thin protective covering of self-curing glass ionomer base was applied on top of the capping material. The dentist provided instant permanent restoration employing direct posterior composite resin. Follow-up examinations were conducted three, six, nine, and 12 months after the procedure, during which assessments were performed using clinical and radiographic parameters. Results The minimum age of the study group was 16, and its maximum age was 34 (22.35 ± 2.3 years). The control group consisted of 12 males and 18 females, while the Biodentine group consisted of 13 males and 17 females. The age and gender distribution were determined to have insignificant statistical differences across the groups. The pain score exhibited statistical significance at both the three-month and six-month follow-up visits (p < 0.05). The pain score at the 12-month follow-up was 0.38 ± 0.52 in the case group and 0.42 ± 0.61 in the control group (p = 0.79). The average Periapical Index (PAI) score for the Dycal and Biodentin groups after the 12-month follow-up was 1.38 ± 0.97 and 1 ± 0.3, respectively. This difference was found to be statistically significant (p = 0.044). In addition, there was a statistically significant difference in the PAI score at the three-month, six-month, and nine-month follow-ups (p < 0.01). During the entirety of the follow-up duration, one individual in the Biodentine group had tenderness upon percussion, a negative reaction for pulp vitality, pulpal changes, and a widening of the periodontal space. Statistically significant differences were observed in pulpal changes and tenderness on percussion during the nine-month and 12-month follow-up periods (p < 0.05). After 12 months, the rate of success in the group treated with Dycal was 91.3%, while the success percentage in the group treated with Biodentine was 98.55%. This difference in outcomes was determined to be statistically significant (λ2 = 5.46; p = 0.019). Conclusion The study findings indicate that Biodentine, a novel tricalcium silicate cement, outperforms calcium hydroxide in preserving pulp vitality over the long term following dPC. The Biodentine group attained an overall success rate of 98.55%, whereas the Dycal group had a success rate of 91.3% following 12 months of subsequent follow-up visits.

Surgical and Non-surgical Repair of Iatrogenic and Carious Perforation using Biodentine: A Case Report

Perforations during root canal treatment are unsolicited complications that occur due to various reasons and may affect the prognosis of the treatment. Amongst the plethora of materials available, Calcium Silicate cements have proven to be the material of choice for perforation repair with strong evidence of success in literature due to their osteogenic potential. This case report discusses surgical and non-surgical repair of carious and iatrogenic perforations using Biodentine as repair material. Keywords: Perforations, root canal treatment, Biodentine, carious and iatrogenic perforations.

How Does Ethylenediaminetetraacetic Acid Irrigation Affect Biodentine? A Multimethod Ex Vivo Study.

The activity of biomaterials used during endodontic treatment can be affected by various factors. One of them is the chemical action of the irrigant that they are exposed to. The aim of this multimethod ex vivo study was to evaluate the influence of ethylenediaminetetraacetic acid (EDTA) on the surface appearance and chemical composition of Biodentine used in perforation repair. Twenty material specimens were prepared according to manufacturers' recommendations and divided into two setting-time-based groups, tested after 45 min (group A) and 24 h (group B) of setting. Material was irrigated with 17% EDTA solution with or without simultaneous ultrasonic activation. The surface characteristics and the chemical composition analysis of the Biodentine specimens were performed with the aid of a scanning electron microscope (SEM) and an energy dispersive spectroscopy (EDS) method, respectively. The volumetric loss of material was measured by dedicated digital software in an optical microscope. Statistical analysis was performed. The EDS study confirmed that after the rinsing protocol, the percentage content of elements differed between the groups. The EDTA rinse, whether ultrasonically activated or not, visibly affected the surface appearance and chemical composition of Biodentine. The specimens' surface subjected to irrigation was more irregular under SEM than in a control group. The US activation of the liquid amplified its impact on the tested material. The average volume loss in group A after 5 min irrigation was 3.98 µm3 for each µm2 of the chosen area and it increased up to 7.74 µm3/μm2 after the ultrasonic activation. In group B, indicated volume loss values were 6.30 and 11.70 µm3/μm2 for 5 min irrigation without and with US activation, respectively. Using a 20 min irrigation time and ultrasonic activation increased it up to 32.71 µm3/µm2. Each rinsing protocol involving irrigation with ethylenediaminetetraacetic acid modified the surface features and the chemical composition of the evaluated hydraulic tricalcium silicate cement. Further research is needed to indicate the possible impact of the observed changes on its long-term clinical performance.

Novel material to enhance the integrity of CCUS cement sheath: Exploration and application of calcium aluminate cement

Carbon dioxide (CO2) emissions are being reduced using the technique known as CCUS (Carbon Capture, Utilization, and Storage). At present, cementing cement paste based on ordinary silicate cement (OPC) and compounded with CO2 corrosion-resistant materials are often used in CCUS wells. CAC cement is characterised by low alkaline hydration content and its study in CCUS wells has rarely been reported. Therefore, CAC cement will be a new cement material for CCUS wells. In this study, we have developed an experimental device to simulate the working conditions of CCUS based on the actual well conditions of CCUS and investigated the effects of stress-coupled CO2 corrosion environment on the performance of CAC cement. According to the experimental findings, CAC cement's compressive strength degraded at a rate of 30.6% after 60 days of CO2 corrosion, which was lower than that of OPC cement (38.3%). When compared to OPC cement, the peak strain and stress of CAC cement increased by 57.2% and 7.85%, respectively. Furthermore, compared to OPC cement sheath, the CAC cement sheath's bearing capacity increased by 8 MPa after stress corrosion, and the crack area of the CAC cement sheath after failure was considerably smaller at 275 mm3 than at 735 mm3. Additionally, after being subjected to stress-coupled CO2 corrosion, the integrity of the CAC cement sheath was much superior to that of the OPC cement sheath, offering a fresh viewpoint for building CCUS cement slurry systems.

Evaluation of biocompatibility and bioactive potential of Well-Root PT by comparison with ProRoot MTA and Biodentine

Background/purposeWell-Root PT is a novel bioceramic material developed to overcome limitations of conventional calcium silicate cements. The purpose of this study was to assess the biocompatibility and bioactivity of a premixed putty-type cement, Well-Root PT. Materials and methodsIdentical cylindrical samples were prepared from ProRoot MTA, Biodentine, and Well-Root PT. In vitro calcium weight volume and calcium ion release from the materials were evaluated with scanning electron microscopy and energy-dispersive spectroscopy and inductively coupled plasma-optical emission spectroscopy. An in vivo rat direct pulp capping model was implemented with the materials (n = 14 per material). The rats were sacrificed at 7 or 28 days. Hematoxylin and eosin and immunohistochemical analyses were performed. ResultsIn vitro calcium weight volume was 42.83 ± 8.82 % in ProRoot MTA, 47.05 ± 8.83 % in Biodentine, and 29.99 ± 4.94 % in Well-Root PT. Calcium ion releases from Well-Root PT after 7 and 28 days were similar with those from ProRoot MTA, but lower than those from Biodentine (P = 0.001 after 7 and 28 days equally). In an in vivo rat model, hematoxylin and eosin analysis showed no significant differences in inflammatory infiltration (P = 0.393) and hard tissue formation scores among the materials (P = 0.905). Also, both CD68 and DSPP expression showed similar results, with no significant differences among the materials (equally P = 0.874 for both markers). ConclusionWithin the limits of this study, Well-Root PT was comparable to ProRoot MTA and Biodentine in terms of biocompatibility and bioactivity.

Biodentine™ as a temporary filling in deep carious lesions in permanent teeth: a prospective observational 33-month follow-up study.

The study aimed to evaluate temporary fillings using Biodentine™ in asymptomatic deep carious lesions after 12, 24, and 36months in school children from the remote village of Kerung, Nepal. From November 2018 to November 2019, 91 temporary fillings were placed using Biodentine™ (a hydraulic calcium silicate cement) in permanent molars with deep carious lesions of schoolchildren in the remote district of Kerung, Nepal. These restorations were performed after selective caries removal in a non-dental setting with hand instruments and cotton roll isolation, as electric motors and saliva ejection systems were unavailable. In total, 78 single-surface and 13 multi-surface fillings were placed. Clinical and radiographic follow-up periods encompassed 12, 21, and 33months, respectively. After 12months, all single-surface fillings (100%) survived, whilst all multi-surface fillings were partially or entirely lost. The survival rate of single-surface restorations after 21 and 33months was 67.6% and 50%, respectively. Radiographically, no pathology was observed. This study showed that Biodentine could be used in deep carious lesions as a temporary filling in single-surface lesions for at least up to 1year and in a substantial number of cases for up to 21 and 33months.

Nano-micron soda residue as green nucleation seeding additive for silicate cement

Soda residue (SR) is a kind of by-product by the ammonia-alkali process in the soda ash production, which contains calcium components, such as calcium sulfate and calcium chloride. In this work, the feasibility of using SR as an accelerating additive for Portland cement (PC) was investigated. Wet milling method was used to prepare nano-micron SR seed with D50 of 246 nm. A binary system of PC and SR seed was designed, and its compressive strength, hydration kinetics and microstructure were studied. Results showed that the 12-hour compressive strength of PC was greatly increased by 1.69 times when the dosage of SR seed was 6%. This improvement was attributed not only to the nucleation seeding and filling effect of the SR seed, but also to the presence of pre-dissolved chlorine and sulfate ions from SR particles. Furthermore, the pore volume was reduced by more than 16%, the critical pre radius was decreased by 86.3%, and the gel pore content was 2.3 times that of reference group, indicating a high microstructure refinement and gel binding contribution of SR seed.

Research on the Performance of Cement-Based Composite Borehole Sealing Material Based on Orthogonal Test.

In order to achieve better sealing of boreholes, the performance of sealing materials is modified to improve the efficiency of coalbed methane extraction. In this paper, a new type of cement-based hole sealing material was prepared by using silicate cement (PC) and cement sulfoaluminate (SAC) as raw materials, supplemented with various additives, such as fly ash, Na2SO4, Ca(OH)2, and poly(vinyl alcohol) (PVA) fiber. The effects of these additives on the fluidity, setting time, and compressive strength of the PC-SAC compounded cementitious pore sealing material were investigated by orthogonal tests, and the hydration process and hydration products were analyzed by X-ray diffraction (XRD), thermogravimetry-differential thermogravimetry (TG-DTG), and scanning electron microscopy (SEM). The results show that the water-cement ratio has the most significant influence on the various properties of the material; the two additives of Na2SO4 and Ca(OH)2 play a key role in the setting time of the material; the optimal group, i.e., water-cement ratio of 0.5, fly ash of 5%, Na2SO4 of 1%, Ca(OH)2 of 0.75%, and PVA fibers of 0.8%, is obtained by the orthogonal test method, which is the closest to the actual needs of the project. The hydration products of the optimized materials have obvious changes, and the needle-like AFt and C-S-H increase so that the performance of the materials has been significantly improved.

Randomized clinical trial of pulpotomy using a premixed injectable calcium silicate cement on mature permanent teeth with reversible pulpitis

The aim of this two-center randomized controlled trial was to assess the outcomes and relative factors associated with pulpotomies performed using a premixed injectable calcium silicate cement, as compared to mineral trioxide aggregate in mature permanent premolar and molar teeth with reversible pulpitis. Included teeth were randomly divided into two groups according to pulpotomy material (ProRoot MTA [PMTA] group, Endocem MTA Premixed [EPM] group). After pulp exposure, the superficial pulp was either removed to a depth of 2 mm (partial pulpotomy) or completely amputated to the level of the root canal orifice (full pulpotomy). A 3-mm layer of either material was randomly placed over the pulp wound, followed by the application of a thin layer of a light-cured glass ionomer composite liner. The restoration procedure was then carried out during the same visit. After one year of treatment, the pulpotomy success rate was 94.4% (67/71), with no significant difference between the PMTA and EPM groups. The success rate was 93.9% in the PMTA group and 97.1% in the EPM group. There were no significant factors related to the procedures. EPM is a viable alternative to PMTA for single-visit pulpotomies of permanent premolars and molars.

Endodontic management of submerged roots following complicated traumatic dental injury (TDI) in children and adolescents: A systematic review.

The International Association of Dental Traumatology (IADT) guidelines include the use of decoronation for the management of complex crown-root fractures but do not outline how this technique is best employed. The aim of this review is to reach a consensus in the management of the root canal system in decoronated permanent teeth undergoing root submergence and to determine whether this has an impact on the success and survival of the retained root. Search included databases MEDLINE via Ebsco, EMBASE via Ovid, Web of Science via Clarivate, PubMed via PubMed.gov, the Cochrane Library via Wiley, cited reference searching and hand searching of relevant journals. Two independent reviewers performed study selection, data extraction and risk of bias assessment using Joanna Briggs Institute (JBI) Critical Appraisal Checklist. In total, 18 articles were included in qualitative analysis: 17 of these were case reports and one case series. A total of 37 teeth were treated with decoronation either using the Malmgren or an alternative protocol (root submergence following endodontic treatment with gutta-percha [GP] or a calcium silicate cement and vital root submergence). Limited evidence from this review suggests that immediate decoronation and vital root submergence are successful in apexogenesis and preserving alveolar bone. This systematic review has been registered in the International Prospective Register of Systematic Reviews (PROSPERO: registration number CRD42022316266).

Antibacterial Potential of Pulp Capping Materials

A critical analysis of the antibacterial effect of the main representatives of calcium silicate cements (CSCs) was made. An analysis of the most frequently used methods for screening the antibacterial activity of materials has been made. The inhibitory activity of CSCs against major types of microorganisms such as Candia albicans, E. faecalis, and strains streptococcus was evaluated and compared. The antibacterial effects of CSCs are not yet well and completely known because no evidence compares the antibacterial properties of bioceramic materials with a uniform methodological approach. It is important to provide standardization of testing methods for evaluating the antibacterial potential of the materials and different bacterial strains. To this stage, there are no reproducible and standardized methods for evaluating of antibacterial activity of CSCs.

Synthesis of a Calcium Silicate Cement Containing a Calcinated Strontium Silicate Phase.

The positive effects of strontium on dental and skeletal remineralization have been confirmed in the literature. This study aimed to assess the properties of a calcium silicate cement (CSC) containing a sintered strontium silicate phase. The calcium silicate and strontium silicate phases were synthesized by the sol-gel technique. Strontium silicate powder in 0 (CSC), 10 (CSC/10Sr), 20 (CSC/20Sr), and 30 (CSC/30Sr) weight percentages was mixed with calcium silicate powder. Calcium chloride was used in the liquid phase. X-ray diffraction (XRD) of specimens was conducted before and after hydration. The setting time and compressive strength were assessed at 1 and 7 days after setting. The set discs of the aforementioned groups were immersed in the simulated body fluid (SBF) for 1 and 7 days. The ion release profile was evaluated by inductively coupled plasma-optical emission spectrometry (ICP-OES). Biomineralization on the specimen surface was evaluated by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Data were analyzed by the Kolmogorov-Smirnov test, one-way and mixed ANOVA, Levene's test, and LSD post hoc test (P < 0.05). Except for an increasement in the peak intensity of hydrated specimens, XRD revealed no other difference in the crystalline phases of hydrated and nonhydrated specimens. The compressive strength was not significantly different at 1 and 7 days in any group (P > 0.05). The setting time significantly decreased by an increase in percentage of strontium (P < 0.05). Release of Ca and Si ions significantly decreased by an increase in percentage of strontium (P < 0.05). SEM/EDS showed the formation of calcium phosphate deposits at 1 and 7 days. Incorporation of 10-30 wt% sintered strontium silicate phase as premixed in CSC can significantly decrease the setting time without compromising the compressive strength or biomineralization process of the cement.

Revascularization of Non-Vital, Immature, Permanent Teeth with Two Bioceramic Cements: A Randomized Controlled Trial

The aim of this study was to clinically and radiographically assess the effects of two bioceramic cements as coronal plug materials for the revascularization of non-vital, immature, permanent teeth with apical periodontitis. Twenty non-vital, immature, permanent, anterior teeth with apical periodontitis were included in this study. Samples were randomly divided into two groups based on the coronal plug materials used; group I (GI): Well Root PT (Vericom, Gangwon-do, Korea) and group II (GII): MTA Biorep (Itena Clinical, Paris, France) (n = 10). Follow-up was conducted clinically and radiographically for up to 12 months to evaluate the changes in root dimensions and resolution of the periapical disease and investigate the degree of success. Data were statistically analyzed using ANOVA tests and Mann–Whitney U tests at a 0.05 significance level. At 12 months, none of the patients in either test group had clinical signs/symptoms. There was a slight increase in root length (4.4% in GI and 3.4% in GII) and a slight increase in dentin wall thickness (10.2% in GI and 9.9% in GII) with no statistically significant (p &gt; 0.05) differences. Whilst there was a significant decrease in lesion dimension in all patients after 12 moths of treatment (93% in GI and 91% in GII), there were no statistically significant differences between the two study groups (p &gt; 0.05). Regarding the degree of success, all cases (100%) achieved the primary goal (the elimination of symptoms and the evidence of bony healing), while 60% in GI and 40% in GII achieved the secondary goal (increased root wall thickness and/or increased root length). No statistically significant difference was found between groups (p &gt; 0.05). Both bioceramic cements showed satisfactory clinical and radiographic findings. Premixed calcium aluminosilicate and tricalcium silicate cements could be used as coronal plug materials in revascularization procedures. Bioceramic cements can be considered promising coronal plug materials for the revascularization of immature, permanent teeth with necrotic pulps and apical periodontitis due to their physicochemical and biological properties.

Delayed vs. immediate placement of restorative materials over Biodentine and RetroMTA: a micro-shear bond strength study

BackgroundThe aim of the present study was to investigate the micro-shear bond strength (µSBS) of various restorative materials applied on two different fast-setting calcium silicate-based materials and to evaluate the effect of restoration time on µSBS.MethodsA total of 180 acrylic blocks with a cavity in the center were randomly divided into 2 main groups according to the capping material to be used (Biodentine or RetroMTA). The specimens were also randomly divided into 3 groups according to the restoration time (3 min, 12 min, 24 h). After the specified waiting periods, glass hybrid material (EQUIA Forte HT), resin composite (Filtek Z550) and light-cured calcium silicate material (Theracal LC) were placed on the specimens with tygon tubes. The specimens were kept for 24 h and then subjected to µSBS test. Statistical analysis was performed by 3-way ANOVA followed by Tukey test for pairwise comparisons (α = 0.05).ResultsThere is a statistically significant difference (p < 0.05) between the µSBS values obtained by applying resin composite on RetroMTA after different setting times (24 h > 12 min > 3 min). The µSBS obtained for the Biodentine-resin composite at the end of the 3 min setting time is significantly lower (p < 0.05) than the µSBS values at 12 min and 24 h. For both calcium silicate cements, at the end of all time periods, the µSBS obtained when resin composite was applied at the end was higher than the other materials (p < 0.05).ConclusionsFor Biodentine-resin composite bonding, the manufacturer’s recommendation of 12 min can be considered an appropriate time, whereas for RetroMTA-resin composite bonding, the µSBS increased as the waiting time increased. Regardless of the waiting time, it is recommended to prefer direct composite resin restoration over Biodentine and RetroMTA.