Evaluation of the bond strength of different adhesive agents to a resin-modified calcium silicate material (TheraCal LC)

Comparative evaluation of shear bond strength and modes of failure of five different reinforced glass ionomer restorative cements to TheraCal LC: An in vitro study

Aim

The aim of the study is to evaluate and compare the shear bond strength (SBS) and modes of failure of different reinforced glass ionomer cement restorative materials such as GC IX, GC Gold Label 2 LC, Amalgomer CR, Equia Forte, and Secure Core Z to TheraCal LC.

Methodology

A total of 50 acrylic blocks, each containing a cylindrical hole in the center were prepared from self-cure acrylic resin and randomly divided into five groups and restored, namely Group A - TheraCal LC + GC Fuji IX, Group B - TheraCal LC + GC Gold Label 2 LC, Group C - TheraCal LC + Amalgomer CR, Group D - TheraCal LC + Equia Forte, and Group E - TheraCal LC + Secure Core Z. All the specimens were stored in artificial saliva at 37°C for 24 h before testing. The statistical tests used for the analysis of the result were: one-way ANOVA, Tukey multiple comparison test, and the Chi-squared test, and P < 0.05 is considered as the level of significance.

Results

Equia Forte showed the highest SBS, while GC type IX showed the lowest SBS with TheraCal LC.

Conclusion

Equia Forte can be the restorative material of choice when TheraCal LC is used as a base materials for better clinical efficacy.

Comparative Evaluation of Shear Bond Strength of Tricalcium Silicate-based Materials to Composite Resin with Two Different Adhesive Systems: An In Vitro Study

Background

Establishing a strong bond between the pulp capping agent and the restorative material is crucial to the success of the procedure. Without this bond, there is a risk of bacterial infiltration into the pulp, leading to treatment failure. In the past, calcium hydroxide was commonly used for such treatments, but it faced challenges, including poor adhesion to dentin, dissolution over time, and the development of multiple tunnel defects. Mineral trioxide aggregate (MTA), introduced to dentistry in 1993, offered an alternative but came with drawbacks like challenging handling and extended setting times. However, in recent times, several new calcium silicate-based materials have emerged to address MTA's limitations. Two notable examples are Biodentine and MTA Plus. Biodentine, for instance, exhibits excellent sealing ability, while MTA Plus distinguishes itself with a finer particle size compared to traditional MTA. These innovative materials offer promising solutions to enhance the efficacy of pulp capping procedures.

Aim

Therefore, in this research, we conducted a comparative analysis of the shear bond strength (SBS) between composite resin and three materials-MTA, MTA Plus, and Biodentine. We examined the effects of applying two distinct adhesive systems in order to evaluate their influence on the bond strength.

Materials and methods

A total of 60 acrylic blocks were evenly distributed into three groups, each containing 20 blocks-group I received Biodentine, group II was assigned MTA, and group III received MTA Plus. The respective test materials were compacted into the holes within the blocks. Following this, the samples were incubated for a period of 72 hours. Subsequently, the samples were divided into two subgroups, each consisting of 10 blocks-the self-etch and the total-etch subgroup. The SBS values were then carefully measured for analysis.

Result

The SBS of the Biodentine group demonstrated a significantly higher value when compared to the other groups. It's worth noting that when the self-etch adhesive system was employed, the SBS of all the groups experienced a significant reduction.

Conclusion

Biodentine cement proves to be an effective choice for pulp capping procedures, regardless of the specific adhesive system employed. Notably, the total-etch adhesive system consistently yields higher bond strength when compared to the self-etch adhesive system.

How to cite this article

Kumar V, Showkat I, Manuja N, et al. Comparative Evaluation of Shear Bond Strength of Tricalcium Silicate-based Materials to Composite Resin with Two Different Adhesive Systems: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(S-3):S272-S277.

In Vitro Study of the Biological and Physical Properties of Dual-Cure Resin-Modified Calcium Silicate-Based Cement

BACKGROUND

The aim of the present study was to compare the biological and mechanical properties of a novel dual-cure, resin-modified calcium silicate material, Theracal PT^® (TP), with those of Theracal LC^® (TL) and Biodentine^TM (BD).

METHODS

The cell counting kit-8 was used on human dental pulp cells to test cell the viability of the three materials. Antibacterial activity of TP, TL, and BD against Enterococcus faecalis was investigated under anaerobic conditions. The ability of the materials to support odontogenic differentiation was studied by examining the relative gene expression of osteocalcin (OCN), osteopontin (OPN), and Collagen I (ColI) using real-time polymerase chain reaction. For mechanical property tests, microhardness was evaluated using the Vickers microhardness (VHN) test, and the bond strength to the resin was evaluated using a shear bond test machine.

RESULTS

There was no significant difference in cell viability between TL and TP after 48 h, and BD showed the highest cell viability, while TP showed the highest antibacterial effect. At the 12-h time point, there was no significant difference in ColI and OCN expression between BD and TP, but TP showed a higher expression of OPN than BD. However, at the 48-h time point, ColI and OCN showed higher levels of expression for BD than for TP and TL. At the same time point, only OPN had a higher diffusion for TP than for BD. TP demonstrated a VHN of approximately 30-35. This value was higher than that of TL and lower than that of BD. In contrast to VHN, the shear bond strength to resin was significantly higher for TL and TP than for BD.

CONCLUSION

TP showed lower biocompatibility than BD but higher OPN expression and antibacterial effects than BD and TL. TP showed higher shear bond strength than BD and higher VHN than TL and BD at the 24-h time point.

Evaluation of Shear Bond Strength of Resin-Based Composites to Biodentine with Three Types of Seventh-Generation Bonding Agents: An In Vitro Study

Background and Aim. Biodentine refers to a bioactive material commonly applied for dental restoration in clinical practice, but poor adhesion of the Biodentine to the restorative materials could affect the quality and long-term integrity of the final restoration. The study aimed to assess shear bond strength (SBS) of two resin-based composites to Biodentine using three commercially available 7th generation bonding agents. Methods. Forty-eight acrylic blocks having central holes with a nominal diameter of 4 mm and a depth of 2 mm were prepared. The holes of the acrylic blocks were filled with Biodentine, which was prepared following the guidelines provided by the manufacturer. Then, the specimens were divided into six groups (n = 8). Groups 1, 2, and 3, Tetric N-Ceram composite bonded to Biodentine with Tetric N-bond, Xeno V+, Bond Force bond, respectively. Group 4, 5, and 6, Filtek Z350 bonded to Biodentine with the same three adhesives. The specimens were placed in distilled water for 24 hours and tested for the SBS in a universal testing machine at a crosshead speed of 1 mm/min. The test data were listed in a table and independent samples t-test and analysis of variance (ANOVA) were conducted as a part of the statistical analysis. Results. The Tetric N bonding agent achieved the highest SBS followed by Bond Force, and Xeno V and highly significant difference was found. On the other hand, an overall increase in the SBS values of the Tetric N-Ceram resin was noticed in comparison with the Filtek Z350 and the differences was statistically significant. Although the specimens failed in adhesive, cohesive and mixed fracture modes but the cohesive was found to be the dominant failure mode in all groups. Conclusion. Among the tested bonding agents and resin composites, the Tetric N-Ceram composite bonded by Tetric N-bond self-etch adhesive with the Biodentine showed the highest SBS compared to the other combinations.

The micro‐shear bond strength of new endodontic tricalcium silicate‐based putty: An in vitro study

This study aimed to compare in vitro micro-shear bond strength (μSBS) of three different endodontic tricalcium silicate-based materials in contact with a bulk-fill resin-based composite. Thirty cylindrical resin blocks with a hole in the centre (2 mm in depth and 4 mm in diameter) were manufactured with a 3D printer and divided into three groups (n = 10), depending on the calcium silicate cement used: light curing TheraCal LC (Bisco, Schaumburg, IL, USA), liquid-powder NeoMTA 2 (NuSmile Avalon Biomed, Bradenton, FL, USA) and putty NeoPutty (NuSmile, Houston, TX, USA). Each sample was stored for 24 h at 37°C and 100% humidity. Then, after adhesive placement, the restorative material Filtek bulk-fill (3 M ESPE, St. Paul, MN, USA) was placed over the capping material using cylindrical plastic capsules (2 mm height and 2 mm) and polymerised for 20 s. Specimens were then tested in a universal testing machine for the compression load resulting in the μSBS. The data were compared with the one-way ANOVA (Welch) and the Tamhane test. The mean value was significantly higher in the TheraCal LC group than in the other two groups (p < 0.05). There was no significant difference between NeoMTA 2 and NeoPutty groups (p > 0.05). The majority of failure modes for all groups were cohesive within biomaterial. Using TheraCal LC in the pulp capping procedure can result in higher bond strength values to the tested bulk-fill resin-based composite than NeoMTA 2 and NeoPutty.

Bond Strength of Adhesive Systems to Calcium Silicate-Based Materials: A Systematic Review and Meta-Analysis of In Vitro Studies

Since the adhesion of resin composites to calcium silicate-based cement is considered challenging. Therefore, the best adhesion strategy should be indicated. This review aimed to assess the effect of different adhesive systems on the bond strength of resin composite to calcium silicate-based cement through a systematic review and meta-analysis. The subsequent PICOS framework used was: population, calcium silicate-based cement; intervention, use of self-etch adhesive systems; control, use of total-etch adhesive systems; outcome, bond strength; study design, in vitro studies. The literature search was conducted independently by two reviewers up to 18 February 2021. Electronic databases (PubMed, ISI Web of Science, SciELO, Scopus, and Embase) were searched for applicable articles. In vitro manuscripts studying the effect of adhesive systems on the bond strength of calcium silicate-based cement were considered. The meta-analyses were performed using Review Manager Software version 5.3.5 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark). Bond strength comparisons were made considering the type of calcium silicate-based cement (Mineral Trioxide Aggregate (MTA), Biodentine™, or TheraCal LC®). A p-value < 0.05 was considered statistically significant. A total of 7321 studies were retrieved in databases searched. After full-text evaluation, 37 eligible papers were assessed for qualitative analysis, leaving a total of 22 papers for the quantitative analysis. According to the meta-analysis, the bond strength values of resin composite materials to MTA and TheraCal LC® cement were favored when a total-etch adhesive system was used (p ≤ 0.02). On the other hand, the meta-analysis of the bond strength of resin-based materials to Biodentine™ calcium silicate-based cement was similar between both approaches (p = 0.12). The in vitro evidence suggests that the bond strength of resin-based materials to both MTA and TheraCal LC® cement was preferred by using the total-etch adhesive strategy. However, when bonding to Biodentine™, the use of self-etch or total-etch strategies displayed promising results. Given the lack of evidence related to the chemical interaction of self-etch adhesive materials with the bioceramics, if self-etch adhesives are used for bonding resin-based restorations to calcium silicate-based cement, a pretreatment with phosphoric acid could be recommended.

Influence of intracoronal bleaching agents on the bond strength of MTA cements to composite resin and their surface morphology

The objective of the present in vitro study was to evaluate micro-tensile bond strength (µSBS) of MTA cements to composite resin using a universal adhesive after internal bleaching procedure, and to examine surface characteristics of MTA cements exposed to bleaching agents. MTA specimens were divided into three subgroups according to the bleaching agent used which were, 37% carbamide peroxide (CP), 35% hydrogen peroxide (HP), and no exposure as a control group (n = 12). After exposure to bleaching agent, composite resins were applied to MTA surfaces using a universal adhesive in self-etch mode. The specimens were exposed to a shear force until failure to evaluate bond strength. MTA surfaces were investigated using scanning electron microscopy (SEM) to observe the effects of the bleaching agents. Differences between groups were analyzed using two-way ANOVA test and intergroup comparisons were assessed with Tukey test (p < 0.05). Although there was a slight difference in bond strength between bleaching agents (CP and HP), no significant difference was found, irrespective of MTA cement. After the HP application, the bond strength values decreased approximately by half compared with the controls. SEM results demonstrated distinct morphological differences between the intact MTA surface (control) and treated MTA surface. Distinct micro-cracks, surface irregularities, and capillary voids formed due to the superficial dissolution caused by peroxides. Exposure to the intra-coronal bleaching agents had a negative influence on the surface morphology of MTA cements and their bond strength to composite resin.

In vitro bioactivity of newly introduced dual-cured resin-modified calcium silicate cement

Background:

This study was designed to investigate the in vitro bioactivity of a new dual cured calcium silicate cement (TheraCal PT) compared to its light cured (TheraCal LC) and chemically set (Biodentine) counterparts.

Materials and Methods:

The study is an in vitro original research article. Prepared cements discs were immersed in deionized water. Ca²+ release was evaluated using inductively coupled plasma-optical emission spectrometry while pH was assessed using a pH meter after 1, 14, and 28 days. Discs for surface characterization were immersed in phosphate-buffered saline (PBS) and were examined using an environmental scanning electron microscope with energy dispersive X-ray (ESEM/EDX), immediately after setting and at 1, 14, and 28 days intervals after that. Attenuated total reflectance (ATR)/Fourier transform infrared (FTIR) and Raman spectroscopy analyses were performed after setting and after 28 days storage in PBS. Statistical analysis was performed using the two-way repeated measure analysis of variance test followed by Bonferroni test for multiple comparisons (P < 0.05).

Results:

Biodentine exhibited the highest mean values for Ca²+ release (792,639,278 ppm) and pH (10.99, 12.7, 11.54) at all time intervals. ESEM/EDX displayed a continuous layer of calcium phosphate formed by Biodentine and TheraCal LC while TheraCal PT developed scarce interrupted precipitates after immersion in PBS. ATR/FTIR and Raman spectroscopy for the formed precipitates confirmed the presence of phosphate and Ca (OH) ₂ in Biodentine, TheraCal LC and TheraCal PT.

Conclusion:

TheraCal PT exhibited limited in vitro bioactivity which may limit its prognosis in clinical applications for vital pulp therapy. TheraCal LC is considered a potential bioactive calcium silicate cement despite its lower Ca²+ release compared to Biodentine. Highest bioactivity was observed in Biodentine.

Evaluation of the Bond Strength of Different Pulp Capping Materials to Dental Adhesive Systems: An In Vitro Study

Aim:

To evaluate the bond strengths of pulp capping materials (Dycal, ProRoot MTA, Biodentine, TheraCal LC, Calcimol LC, and ApaCal ART) and different adhesive systems (Gluma 2 Bond, Clearfil SE Protect, Gluma Self Etch, Clearfil S 3 Bond Plus, Gluma Bond Universal, Clearfil S 3 Bond Universal).

Materials and Methods:

Two hundred fifty-two acrylic blocks were prepared in which cylindrical cavities of 4 × 2 mm 3 were formed. Pulp capping materials were placed in the cavities. Different adhesive systems were applied to each pulp capping material group. After applying the composite resin, the shear bond strength (SBS) values of the specimens were determined in the Instron test device. Fracture types were evaluated using a stereomicroscope and a scanning electron microscope. Data were analyzed by Shapiro–Wilk’s and Kruskal–Wallis H test.

Results:

There is a statistically significant difference between pulp capping materials in terms of SBS values ( P < .05). Dycal’s SBS was found significantly lower than other materials, and the highest bond strength was observed in Calcimol LC material. Although there is no statistically significant difference ( P > .05) between the adhesive agent groups in terms of SBS, Gluma 2 Bond showed the highest bond strength value.

Conclusion:

In traditional pulp capping materials such as Dycal, MTA, and Biodentine, using a two-step self-etch adhesive system can result in higher bond strength values. In resin-based TheraCal LC,, ApaCal ART, and Calcimol LC materials, it may be recommended to use a two-step etch and rinse adhesive system.

Bio-Inductive Materials in Direct and Indirect Pulp Capping-A Review Article

The article is aimed at analyzing the available research and comparing the properties of bio-inductive materials in direct and indirect pulp capping procedures. The properties and clinical performances of four calcium-silicate cements (ProRoot MTA, MTA Angelus, RetroMTA, Biodentine), a light-cured calcium silicate-based material (TheraCal LC) and an enhanced resin-modified glass-ionomer (ACTIVA BioACTIVE) are widely discussed. A correlation of in vitro and in vivo data revealed that, currently, the most validated material for pulp capping procedures is still MTA. Despite Biodentine's superiority in relatively easier manipulation, competitive pricing and predictable clinical outcome, more long-term clinical studies on Biodentine as a pulp capping agent are needed. According to available research, there is also insufficient evidence to support the use of TheraCal LC or ACTIVA BioACTIVE BASE/LINER in vital pulp therapy.

Comparative evaluation of the bond strength of self-adhering and bulk-fill flowable composites to MTA Plus, Dycal, Biodentine, and TheraCal: an in vitro study

Objectives

This study aimed to compare the shear bond strength (SBS) of a self-adhering flowable composite (Dyad Flow) and a bulk-fill flowable composite (Smart Dentin Replacement [SDR]) to several pulp-capping materials, including MTA Plus, Dycal, Biodentine, and TheraCal.

Materials and Methods

Eighty acrylic blocks with 2-mm-deep central holes that were 4 mm in diameter were prepared and divided into 2 groups (n = 40 each) according to the composite used (Dyad Flow or SDR). They were further divided into 4 sub-groups (n = 10 each) according to the pulp-capping agent used. SBS was tested using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed using 2-way analysis of variance. A p value of < 0.05 was considered to indicate statistical significance.

Results

A statistically significant difference (p = 0.040) was found between Dyad Flow and SDR in terms of bond strength to MTA Plus, Dycal, Biodentine, and TheraCal.

Conclusions

Among the 8 sub-groups, the combination of TheraCal and SDR exhibited the highest SBS.

The comparative evaluation of shear bond strength of a bioactive material to different universal bonding agents - An in vitro study

Background:

An ideal dental repair material should possess certain important properties such as adequate adhesive ability, insolubility, dimensional stability, biocompatibility, and bioactivity. Newer materials claiming better performance are continuously being introduced in the market to optimize the care of dental patients.

Aim:

The aim of this study was to evaluate the shear bond strength of three different universal adhesives to OrthoMTA.

Materials and Methods:

Sixty-four specimens of OrthoMTA measuring 4 mm internal diameter and 2 mm height were prepared and divided into two main groups. After 12 min, 32 samples were randomly selected and divided into four subgroups of eight samples each. Subgroup-I: Single Bond Universal, Subgroup-II: Prime-and-Bond NT, Subgroup-III: Palfique Universal bond, Subgroup-IV: Control. After the application of adhesives, the composite resin was applied using a cylindrical plastic matrix of 2 mm internal diameter and 2 mm height over OrthoMTA. This procedure was repeated 24 h after mixing an additional 32 samples, respectively. Shear bond strengths were measured using Universal testing machine and fractured specimen were examined under stereomicroscope. Data were statistically analyzed using a two-way ANOVA test and Tukey's multiple post hoc test.

Results:

Statistical analysis revealed that subgroup-III exhibited higher bond strength at both 12 min and 24 h time intervals. It was also observed that most of the failures occurred cohesively within OrthoMTA.

Conclusion:

Shear bond strength was higher at 24 h than compared to 12 min. Subgroup-III exhibited higher bond strength than other subgroups.

Does Delayed Restoration Improve Shear Bond Strength of Different Restorative Protocols to Calcium Silicate-Based Cements?

The purpose of the present study was to assess the proper time to perform a restoration (immediately or delayed) after placement of two calcium silicate-based cements (CSCs) and to test the performance of two different restorative protocols regarding shear bond strength (SBS). Seventy-five acrylic blocks were randomly divided into five groups (n = 15). Specimens were filled with either ProRoot MTA (Dentsply Tulsa Dental) or Biodentine (Septodont). The restoration was performed at an immediate (12 min) or delayed (seven days) timeframe, using a resin-based flowable composite (SDR) (bonded to the CSC using a universal bonding system) or glass ionomer cement (GIC) as restorative materials. SBS was measured using a universal testing machine. Fractured surfaces were evaluated, and the pattern was registered. Statistical analysis was performed using the Dunn–Sidak post hoc test (P < 0.05). Biodentine/immediate SDR showed the highest mean SBS value (4.44 MPa), with statistically significant differences when compared to mineral trioxide aggregate (MTA)/GIC (1.14 MPa) and MTA/immediate SDR (1.33 MPa). MTA/GIC and MTA/immediate SDR did not present significant differences regarding SBS. No statistical differences were verified concerning mean SBS between both CSCs within the 7 day groups. MTA/delayed SDR (3.86 MPa) presented statistical differences compared to MTA/immediate SDR, whereas no differences were observed regarding Biodentine performance (Biodentine/immediate SDR and Biodentine/delayed SDR (3.09 MPa)). Bonding procedures directly on top of MTA might be preferably performed at a delayed timeframe, whereas Biodentine might allow for immediate restoration.

TheraCal LC: From Biochemical and Bioactive Properties to Clinical Applications

Background

Direct pulp capping is a popular treatment modality among dentists. TheraCal LC is a calcium silicate-based material that is designed as a direct/indirect pulp capping material. The material might be very attractive for clinicians because of its ease of handling. Unlike other calcium silicate-based materials, TheraCal LC is resin-based and does not require any conditioning of the dentine surface. The material can be bonded with different types of adhesives directly after application. There has been considerable research performed on this material since its launching; however, there are no review articles that collates information and data obtained from these studies. This review discusses the various characteristics of the material with the aim of establishing a better understanding for its clinical use.

Methods

A search was conducted using search engines (PubMed and Cochrane databases) in addition to reference mining of the articles that was used to locate other papers. The process of searching for the relevant studies was performed using the keywords pulp protection, pulp capping, TheraCal, and calcium silicates. Only articles in English published in peer-reviewed journals were included in the review.

Conclusion

This review underlines the fact that further in vitro and in vivo studies are required before TheraCal LC can be used as a direct pulp capping material.

Interface Between MTA and Dental Bonding Agents: Scanning Electron Microscope Evaluation

Aims and Objectives:

Nowadays, the material that offers the best sealing characteristic in the field of endodontic treatment is the mineral trioxide aggregate (MTA), nevertheless, this material necessities an adhesive bonding agent to perfectly join to the dental surface. The aim of this study was to analyze using a scanning electron microscope (SEM) the possible microgap between the adhesive, MTA, and the dental surface.

Material and Methods:

Fourteen extracted molars were divided into two groups – group A was prepared with MTA-component adhesive and group B was prepared with MTA and composite dual etching. The observations were carried out with a SEM Phenom G2 Pro mode S.E.I. JMP® software was used for statistical analysis, and a t-test was used for evaluating the difference between the two groups.

Results:

The gap of the areas at higher magnification (1000×) with a size greater than 5 microns in width and 20 microns in length were considered significant, and only group A recorded significant data.

Conclusions:

The SEM analysis performed in the group A with interposition of adhesive and flow between the dental pulp chamber and MTA demonstrates the presence of a marginal gap of considerable amplitude in the all of the samples investigated.