Shear Bond Strength of Nanohybrid Composite to Biodentine with Three Different Adhesives

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

BACKGROUND

The 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.

METHODS

A 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).

RESULTS

There 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).

CONCLUSIONS

For 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.

Effects of surface treatments of bioactive tricalcium silicate-based restorative material on the bond strength to resin composite

OBJECTIVES

This study aimed to enhance the bond strength between Biodentine™ (BD), a bioactive tricalcium silicate (C3S) based material, and resin composite through various surface treatments.

METHODOLOGY

BD samples were immersed in either double distilled water or Hank's Balanced Salt Solution and analyzed using X-ray Diffraction (XRD). Shear bond strength (SBS) evaluations of BD were performed using Prime & Bond™ NT (PNT), Single Bond Universal (SBU), Xeno V (Xeno), and glass ionomer cement (GIC) following various etching durations (0 s/ 15 s/ 30 s/ 60 s with 37.5% phosphoric acid). Two primers, RelyX™ Ceramic Primer (RCP) and Monobond ™ Plus (MBP), were chosen to prime BD for SBS enhancement. Fractography and bonding interfaces were examined with energy dispersive X-ray spectroscopy (EDS)/ scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR).

RESULTS

XRD confirmed BD's main compositions as C3S, Ca(OH)2, CaCO3 and ZrO2 after 14 days crystal maturation. Etched BD did not improve SBS. GIC exhibited the lowest SBS (p < 0.05) among all adhesives, regardless of the etching mode (all < 1 MPa). The highest SBS (17.5 ± 3.6 MPa, p < 0.05) was achieved when BD primed with MBP followed by SBU application. FTIR and EDS showed γ-MPTS and10-MDP within the MBP primer interacted with C3S and ZrO2 of BD, achieving enhanced SBS. Most specimens exhibited mixed or cohesive failure modes. Significance BD's subpar mechanical properties and texture may contribute to its poor adhesion to resin composite. Pretreating BD with MBP primer, followed by SBU adhesive is recommended for improving bond strength.

Comparative evaluation of shear bond strength of calcium silicate-based liners to resin-modified glass ionomer cement in resin composite restorations - a systematic review and meta-analysis

Purpose The aim of this systematic review was to evaluate the difference in shear bond strength between calcium silicate-based liners to resin-modified glass ionomer cement (RMGIC) in resin composite restorations.Materials and methods The protocol was registered in PROSPERO following which primary research was carried out on Medline, Scopus and Cochrane library. To assess the risk of bias, a customised tool was used. Among the 194 records retrieved from the databases, only ten articles qualified for qualitative and quantitative synthesis after meeting all the requirements of the eligibility criteria. Covidence software was used to record the decisions. Studies published until 31 March 2021 were taken up for the review. The articles showed a low-to-moderate risk of bias. I2 test was used to check the percentage variation due to heterogeneity.Results RMGIC showed a higher shear bond strength value compared to the three calcium silicate liners MTA, Biodentine and TheraCal LC. However, TheraCal LC and MTA showed better bond strength than Biodentine. Cohesive failure was seen predominantly in liners followed by adhesive failure. RMGIC shows mixed mode of failure in some studies.Conclusions RMGIC is preferred over calcium silicate-based materials as the liner to be used under resin composite restorations. Among calcium silicate-based materials, TheraCal LC showed a better bond strength value. The mode of failure was predominantly cohesive in all the liner groups in majority.

Complicated Crown Fracture of Permanent Incisors: A Conservative Treatment Case Report and a Narrative Review

Dental trauma may have a severe impact on the social and psychological wellbeing of a patient. Most cases of dental injuries involve anterior teeth, especially the maxillary upper incisors. Crown fractures, with or without pulp exposure, are the most common trauma in permanent dentition. There are many methods of management, in which the initial state of the pulp, the time since the injury, and the presence of an accompanying injury play a key role. This case report aimed at showing a possible conservative treatment after complicated tooth fracture that consisted of partial pulpotomy followed by adhesive reattachment of the tooth fragment using a technique based on heated resin composite. Such a specific procedure represents a conservative approach to traumatic coronal lesions, providing a suitable opportunity to maintain the tooth vitality, aesthetics, and function. Indeed, reattachment of tooth fragment using a composite/adhesive is a simple technique to achieve excellent results in terms of aesthetic and function.

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.

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.

Effect of Bioinductive Cavity Liners on Shear Bond Strength of Dental Composite to Dentin

Background

The aim of the current study was to evaluate and compare the influence of Dycal, Lime-Lite, TheraCal LC, Biodentine, resin-modified glass ionomer cement (RMGIC), and Activa BioActive as the pulp capping material on the shear bond strength of resin composite to dentin.

Methods

A total of 70 extracted caries-free molars were randomly assigned to seven groups. Six test groups were covered with various protective liners: Dycal, TheraCal LC, Lime-Lite, Activa BioActive, Biodentine, and RMGIC. The control group received no liner pretreatment. Each sample was bonded to resin composite using the total-etch Tetric N bond adhesive. The samples were then tested for shear bond strength using the universal testing machine at a cross-head speed of 1 mm/min until bond failure occurred. The data were analyzed using the one-way ANOVA test followed by the Tamhane post hoc test for pairwise comparisons of the groups.

Results

Independent of the type of the applied liner, all groups exhibited inferior SBS to dentin compared to the control group. TheraCal and RMGIC showed significantly higher shear bond strength than Biodentine and Dycal, which showed the lowest shear bond strength. Lime-Lite and Activa also had significantly lower SBS results than TheraCal. The mode of fracture was predominantly cohesive in Dycal, Biodentine, and TheraCal and adhesive in Activa.

Conclusion

This present study concludes that the bond strength of resin composite to dentin can be affected differently using various types of liners.

Nair P, Shetty H, D'Costa V, Jayaprakash K. Comparative evaluation of shear bond strength of a bioactive material to composite resin using three different universal bonding agents: An in vitro study

Background:

Calcium silicate-based cements or bioceramics have revolutionized and simplified pulp-capping procedures due to its versatility and accessibility.

Aim:

This study aimed to assess the shear bond strength (SBS) of a bioceramic material to composite resin at two aging periods and with three universal adhesives.

Materials and Methods:

Forty-eight samples of Biodentine with a height of 2 mm and internal diameter of 4 mm were prepared. After 12 min of mixing, 24 samples were randomly selected and divided into four subgroups: Group I: Single Bond Universal, Group II: Palfique Universal Bond, Group III: G-Premio BOND, and Group IV: Control. Composite resin was restored over Biodentine after the application of universal adhesives using a cylindrical plastic mold of 2 mm height and 2 mm internal diameter. This process was repeated 24 h after mixing on the remaining 24 samples of Biodentine. The universal testing machine was used to measure the SBS of the fractured specimens, followed by stereomicroscopic evaluation. One-way ANOVA test and Bonferroni post hoc test were used to statistically analyze the data.

Results:

Highest SBS values were observed in Group III at 12 min and 24 h of the setting of Biodentine.

Conclusions:

Compared to the 12-min group, SBS was higher at 24 h. Group III exhibited higher bond strength than other subgroups.

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.

Evaluation of the Interfaces between Restorative and Regenerative Biomaterials Used in Vital Pulp Therapy

BACKGROUND

Calcium-silicate-based cements (CSC) have gained an increasing scientific and clinical relevance, enabling more conservative approaches, namely pulp preservation and regeneration therapies. This research aims to study the influence of four clinical variables on the interfaces between CSC and composite adhesive restoration, concerning shear bond strength (SBS) and ultra-morphological patterns.

METHODS

SBS tests were performed in 320 specimens divided in 16 groups (n = 20) according to: two CSC (NuSmile^® NeoMTA, Biodentine^TM); two adhesive systems (Clearfil^TM SE Bond 2 (CSEB2), Clearfil^TM Universal Bond Quick (CUBQ)); optional application of an additional hydrophobic bonding layer (HBL); two restoration times (immediate, seven days). Scanning electron microscopy (SEM) was performed to conduct the ultra-morphology interface analysis in 32 deciduous molars prepared and randomly allocated into the 16 groups.

RESULTS

Globally, SBS tests showed higher bond strength of CUBQ compared to CSEB2 (p < 0.001), as with an additional HBL application (p = 0.014) and delayed restoration (p < 0.001). SEM showed the interpenetration between adhesive systems and CSC forming a hybrid layer, whose depth and thickness depended on the restoration time and adhesive strategy.

CONCLUSIONS

The independent clinical variables adhesive system, application of an additional HBL and restoration time affected the bond performance and ultra-morphological interface between composite adhesive restoration and CSC.

Comparison of bond strength of universal adhesives using different etching modes: A systematic review and meta-analysis

This review aims to evaluate whether the etch-and-rinse or self-etch mode is the better protocol for dentin adhesion by universal adhesives. A total of 15 articles were included in the meta-analysis. Two reviewers performed a literature search up to October 2020in four databases: PubMed, Web of Science, Embase, and the Cochrane Library. Without considering the difference in aging mode, the analysis of the immediate and long-term bond strength of dentin showed that there was no statistical significance between the etch-and-rinse and self-etch mode of universal adhesive, and the long-term bond strength decreased relative to the immediate. In vitro studies suggest that prior acid etching did not improve bond performance. Whether from the perspective of long-term bonding performance or simplifying operating procedures, the self-etch mode is preferred.

Minimal Intervention in Dentistry: A Literature Review on Biodentine as a Bioactive Pulp Capping Material

Root canal treatment has been the treatment of choice for carious pulp exposures. In the perspective of minimally invasive dentistry and preventive endodontics, a direct pulp capping procedure with a reliable bioactive material may be considered an alternative approach provided that the pulp status is favorable. However, the treatment of pulp exposure by pulp capping is still a controversial issue with no clear literature available on this topic, leaving the concerned practitioner more confused than satisfied. Biodentine is a relatively new bioactive material explored for vital pulp therapy procedures. This article discusses its role in direct pulp capping procedures. A thorough literature search of the database was done using PubMed, Google Scholar, and Scopus using the keywords preventive endodontics, calcium silicate cement, direct pulp capping, Biodentine, and vital pulp therapy. Reference mining of the articles that were identified was used to locate other papers and enrich the findings. No limits were imposed on the year of publication, but only articles in English were considered. This paper is aimed at reviewing the current literature on Biodentine as a direct pulp capping material. The review will provide a better understanding of Biodentine's properties and can aid in the decision-making process for maintaining the vitality of exposed dental pulp with minimal intervention.