An In Vitro Evaluation of Mechanical Properties of a New Dual-cure, Universal, Bioactive Luting Cement.

Aim and background: The aim of this study was to determine the properties of a new luting cement, BioCem®, by evaluating shear bond strength (SBS) and flexural strength (FS). Materials and methods: A total of 60 extracted deciduous molars were included in this study. Samples were divided into two groups: Group I, Fuji I® (n = 30), and group II, BioCem® (n = 30). Each tooth was embedded in one acrylic block, such that the flattened enamel surface was exposed. Cylinders of 6 mm diameter and 8 mm height were prepared and evaluated for SBS using a universal testing machine. Ten rods of 25 × 2 × 2 mm of each material were prepared using a custom mold to evaluate the FS using a universal testing machine. Statistical Package for the Social Sciences (SPSS) version 20.0 was used for statistical analyses. Intergroup analysis was performed using an independent sample t-test. Results: Upon comparing the SBS values of the luting agents and prepared enamel surfaces, glass ionomer cement (GIC) displayed the highest value, while BioCem® displayed the lowest. Upon comparing the FS values of the luting agents and prepared enamel surfaces, BioCem® performed better than GIC. Conclusion: BioCem® may be used as a luting agent for the cementation of stainless steel crowns (SSCs) on primary teeth. Clinical significance: BioCem®, a recently developed luting cement, may be used for cementing SSCs to the surfaces of prepared deciduous teeth; it exhibits significantly higher FS but lower SBS than that of GIC. How to cite this article: Shams SA, Nekkanti S, Shetty S. An In Vitro Evaluation of Mechanical Properties of a New Dual-cure, Universal, Bioactive Luting Cement. Int J Clin Pediatr Dent 2024;17(8):887-891.

An in vitro assessment of the influence of dentinal pretreatment with chlorhexidine, nonthermal atmospheric plasma, chitosan, and proanthocyanidins on shear bond strength to composite.

Context: Dentin biomodification has been emphasized as a means of improving the bond between composite resin and tooth surface, consequently enhancing its longevity. Aim: To evaluate the shear bond strength (SBS) of dentin after pretreatment with 2% chlorhexidine (CHX), 2% chitosan, nonthermal atmospheric plasma (NTAP), proanthocyanidins (5% pine bark ((PB) and 5% bromelain). Settings and Design: The study was designed as an in vitro investigation. Materials and Methods: Sixty extracted mandibular molars (n = 60) were gathered for this in vitro research. The teeth were decoronated to expose the dentinal surface. All samples have been etched with 37% phosphoric acid and then pretreated with respective dentin biomodifiers. Group I (control): No pretreatment was done, Group II: 2% CHX, Group III: NTAP, Group IV: 5% PB, Group V: 2% chitosan, Group VI: 5% bromelain. Specimens were evaluated for the SBS test, which was done under the instron universal machine at a speed of 1 mm/min after a bonding agent and composite build-up were applied. Results: While Group I had the lowest SBS (10.391.59Mpa), Group V had the highest SBS (30.111.53 Mpa). Pretreatment of the dentin enhanced the SBS of dentin to composite. Conclusion: When utilized after etching, dentin biomodification increased all experimental group's bond strength in contrast to the control. The highest SBS values were recorded with 2% chitosan, followed by NTAP.

To compare and evaluate the shear bond strength of sixth-, seventh-, and eighth-generation dentin bonding agents: An in vitro study.

Context: Bonding agents have developed from a multistep bonding process to simplification, i.e. self-etch and single bottle system. Aims: The aim of this study is to compare and evaluate the shear bond strength (BS) of sixth-, seventh, and eighth-generation dentin bonding agents. Settings and Design: This was an in vitro study. Materials and Methods: Three sets of 75 permanent mandibular premolars that had been removed were chosen. A universal testing machine operating at a cross-head speed of 1 mm/min. examined the shear BS of the samples after they had been stored in deionized water for an entire day. Statistical Analysis Used: "One-way analysis of variance and Bonferroni test post hoc analysis" were used for statistically analyzing the data. Results: The sixth-generation group shear BS was noticeably stronger. Conclusions: The sixth-generation dentin bonding agent demonstrated the greatest mean shear BS to dentin because the solvent present had low concentration and low hydrophilicity, polymerization was more extensive, and dentin underlined underwent limited etching and demineralization over an extended period of time.

Evaluation of Antimicrobial Efficiency, Shear Bond Strength, and Adhesive Remnant Index of TiO2 Infiltrated Orthodontic Adhesive - An In Vitro Study.

Background: Enamel demineralization is an unavoidable adverse effect encountered with bonding brackets in orthodontic therapy. Introducing nanoparticles into the composite adhesive paste can prevent enamel demineralization. Titanium dioxide (TiO2) is known to exhibit direct antimicrobial efficiency. This study aimed to assess the antibacterial efficiency and shear bond strength (SBS) of an orthodontic bonding composite infiltrated with TiO2 nanoparticles. Materials and Methods: This in vitro study evaluated the efficiency of TiO2 nanoparticle-incorporated light-curing orthodontic composite paste (ENLIGHT, ORMCO). Twenty extracted premolars were randomly and equally allocated to the two study groups, N = 10. While a conventional composite was utilized for the bonding brackets in Group I, a TiO2-incorporated composite was used in Group 2. The adhesive remnant index (ARI) scores given by Artun and Bergland et al. and SBS were determined. Furthermore, the antimicrobial efficiency was estimated using the minimum inhibitory concentration (MIC)/minimum bactericidal concentration (MBC) and agar well diffusion assay for six composite disc specimens. The results were statistically analyzed using the chi-square test and Student's t test, at P < 0.05. Results: After 24 h of curing, no statistical mean difference was observed between the two groups in terms of ARI or SBS scores (P > 0.05). However, there was a significant increase in the antimicrobial efficiency of Group II when compared with Group I (P < 0.05). Conclusion: TiO2 nanoparticle-incorporated orthodontic composites improve the antimicrobial efficiency with no significant change in the SBS. The ARI scores indicate the presence of 50% remnant orthodontic composite on the tooth enamel surface post debonding.

The Impact of Orthodontic Adhesive Containing Resveratrol, Silver, and Zinc Oxide Nanoparticles on Shear Bond Strength: An In Vitro Study.

Introduction The goal of orthodontic treatment is to provide patients with esthetic smiles and functional occlusion. Despite best efforts and continuous evolution of materials, white spot lesions present a persistent hindrance to the desired treatment outcome. Nanoparticles have shown efficacy in reducing microbial activity; however, currently, there is a need for natural anti-cariogenic compounds with minimal side effects. Resveratrol is a natural compound belonging to the polyphenol group and has shown promising anti-microbial efficacy. This study aimed to evaluate the influence of dentin bonding agents incorporated with the following three different nanoparticles on shear bond strength: silver nanoparticles (Ag-Np), zinc oxide nanoparticles (ZnO-Np), and resveratrol nanoparticles (RSV-Np). Materials and methods A total of 40 premolar teeth therapeutically extracted were assigned to four equal groups of n=10 each. Groups 1, 2, and 3 used experimental adhesives doped with silver, zinc oxide, and resveratrol nanoparticles, respectively. Group 4 was bonded using unmodified adhesive. The bonded teeth were then subjected to shear bond strength (SBS) testing which was measured using a Universal Testing Machine (model no. UNITEST-10; Pune, India: ACME Engineers). Statistical analyses were performed using SPSS version 21 (Armonk, NY: IBM Corp.), employing one-way ANOVA and Tukey's post-hoc test for pairwise comparisons. Results Shear bond strength testing revealed that the control group with unmodified adhesive (8.6 MPa) had the highest SBS, followed by RSV-Np (7.6 MPa), Ag-Np (6.3 MPa), and ZnO-Np (5.65 MPa). Although the experimental groups demonstrated decreased SBS compared to the control, the values for Ag-Np and RSV-Np fell within the acceptable range. Conclusion Resveratrol nanoparticles had the least impact on shear bond strength among the experimental groups. These findings suggest that the incorporation of resveratrol nanoparticles in dentin bonding agents can provide anti-cariogenic effect without significantly impacting the adhesive's mechanical properties thereby providing a new and promising alternative to synthetic nanoparticles. Further studies are recommended to optimize the balance between anti-microbial efficacy and bond strength in clinical applications.

Effect of nonthermal atmospheric plasma application at different time intervals on the dentinal shear bond strength pretreated with 2% chlorhexidine as cavity disinfectant: An in vitro study.

Context: Effective use of nonthermal atmospheric plasma (NTAP) to strengthen adhesive-dentin interfacial bonding while disinfecting with chlorhexidine (CHX). Aim: NTAP application at different time intervals on the dentinal shear bond strength (SBS) after pretreatment with 2% CHX as a cavity disinfectant. Settings and Design: The design of the study was an in vitro study. Materials and Methods: Forty permanent mandibular teeth were collected (n = 40) and the occlusal surfaces were flattened. For, all the specimens 37% phosphoric acid etching was done followed by pretreatment with 2% CHX as cavity disinfectant for 5 s. According to the surface treatment, divided into four groups of n = 10. Group I (Control): No NTAP pretreatment was done. Group II: NTAP pretreatment done for 15 s. Group III: NTAP pretreatment done for 30 s. Group IV: NTAP pretreatment done for 45 s. Later, all the specimens were treated with a bonding agent, incremental build-up of composite resin on the dentin surface was done and evaluation of SBS was done. Analyzed using One-way analysis of variance with a post hoc Tukey's test (P < 0.05). Results: Two percent CHX pretreatment as cavity disinfectant followed by NTAP application for 30 s (Group III) exhibited greater values compared to the control group (Group I). Conclusion: Two percent CHX pretreatment as cavity disinfectant followed by NTAP pretreatment for 30 s was found to exhibit better bond strength values compared to 15 s as well as 45 s.

Effect of Silane-Containing Adhesives on Repair Bond Strength between Fresh and Aged Composite Materials-A Pilot Study.

This study investigated the effects of different surface treatments and a silane-containing adhesive on the repair bond strength between fresh and aged resin composites. A total of 140 composite specimens were prepared and aged for 24 h or 4 months. Each group was subdivided into seven subgroups (n = 10) depending on the surface treatment (no surface treatment (NT), sandblasting (SAND), or Sof-lex coarse disc (DISC)) in combination with the use of the silane-containing adhesive ScotchBond Universal Plus (SBU) or an adhesive without silane Prime&Bond Universal (P&B). The same composite was used for the repair as for the primary specimen. Specimens were dark stored in distilled water at 37 °C for 28 days. Shear bond strength was tested at a crosshead speed of 0.5 mm/min. The Kruskal-Wallis test with Bonferroni's post-hoc adjustment (α = 0.05) and the Mann-Whitney U-test were used for the statistical analysis. The results are shown as the median with the interquartile range. The highest bond strength (MPa) was achieved after 24 h in the DISC+P&B (20.39(16.85-28.83)). In the fresh 24 h group, the SAND+P&B (12.25(8.28-15.05)) and DISC+SBU (18.37(15.16-21.29)) were statistically similar. In the 4-month groups, both adhesives and surface treatments performed similarly. The NT, SAND, and DISC groups without adhesives had the lowest bond strength. In the repair of fresh or aged composite, the silane-containing adhesive SBU was not superior to the adhesive without the silane (P&B).

The effects of optimized microstructured surfaces on bond strength and durability of NPJ-printed zirconia.

OBJECTIVES: This study was to investigate the effects of optimized microstructured surfaces on bond strength and bond durability of the latest nanoparticle jetting (NPJ)-printed zirconia. METHODS: Zirconia microstructured surfaces with different geometries and void volume were analyzed through three-dimensional finite element analysis for surface micromorphology optimization. Zirconia disks and cylinders were additively manufactured by an NPJ 3D printer (N = 128). They were randomly divided into four groups based on surface micromorphology optimization and airborne-particle abrasion (APA) treatment before they were bonded using 10-methacryloloxydecyl dihydrogen phosphate (MDP) containing resin cement (Clearfil SA luting cement). The shear bond strengths (SBSs) were tested before and after 10,000 thermocycles and were analyzed by one-way ANOVA analysis. Failure modes were determined by optical microscopy. Zirconia surfaces were analyzed with X-ray diffraction, scanning electron microscopy, and three-dimensional interference microscopy. RESULTS: The optimized microstructured surface was characterized by circular microstructures with 60 % void volume, about 20 µm of depths, about 10 µm of undercuts, and consistent beam widths. The optimized microstructured surface combined with APA treatment and MDP-containing resin cement possessed the highest SBSs both before and after thermocycling aging (P＜0.05). The greater reductions of zirconia bond strengths occurred when the zirconia were not treated with APA (P＜0.05). SIGNIFICANCE: The optimized microstructured zirconia surface with circular microstructures and 60 % void volume fabricated by the latest NPJ printing technology could greatly enhance the zirconia bond strength and durability in combination with APA treatment and application of MDP-containing resin cement, which might be promising for adhesively bonded indirect restorations of NPJ-printed zirconia.

Effect of Different Liquids and Thermal Aging Procedures on the Shear Bond Strength of APC II, APC Flash-Free, and Conventional Ceramic Brackets: An In Vitro Study.

Objective: The purpose of this study was to compare the effects of cherry juice, coffee, coke, gastric acid, and the thermo-aging procedure (TAP) on the shear bond strength (SBS) of APC II, APC flash-free, and conventional ceramic brackets. Methods: A total of 180 human premolar teeth were randomly divided into three major groups according to the type of ceramic bracket. Then, six subgroups (n=10) were established from each major group: Group 1: control; Group 2: only TAP; Group 3: 72 hours of cherry juice exposure + TAP; Group 4: 72 hours of coffee exposure + TAP; Group 5: 72 hours of coke exposure + TAP; and Group 6: 24 hours gastric acid exposure + TAP. SBS was assessed for each specimen using a universal test device, and the adhesive remnant index (ARI) was scored under a light microscope. Kruskal-Wallis and post-hoc Tamhane tests were used to analyze the data. Results: Among the control groups, the highest SBS value belonged to conventional ceramic brackets (p<0.01). SBS values for all groups decreased as a result of each liquid and TAP. Gastric acid and coke had the greatest detrimental effects on SBS, while TAP had the least negative effects. The SBS values of APC II, APC flash-free, and conventional brackets were found to be statistically insignificant after different liquid exposures and TAP. Conclusion: TAP and various fluids had a negative impact on the SBS value of ceramic brackets. SBS values, however, were still higher than clinically acceptable (8-9 MPa) values, even after exposure to gastric acid and coke.

Shear bond strength of a composite resin restoration in primary teeth following cavity preparation using laser- an in-vitro study.

To evaluate and compare the shear bond strength of composite resin restorations in primary teeth, following cavity preparation with both traditional dental burs and laser irradiation. One hundred primary molars extracted from the children visiting our department were collected and randomly divided into five groups (A-E) with 20 teeth in each group. In groups A, B, C, D, and E the teeth samples were etched with phosphoric acid, Er; YAG laser followed by acid etching, Er, Cr: YSGG laser followed by acid etching, Er; YAG laser etching only and Er, Cr: YSGG laser etching only, respectively. Following, all the samples were restored with composite resin and subjected to 500 cycles of thermocycling. The shear bond strength of the resin composite was analyzed. The type of fractures was also noted. Data obtained were subjected to statistical analysis. The mean value of shear bond strength of Group A, B, C, D, and E was 17.562 ± 0.810, 15.928 ± 0.415, 14.964 ± 0.566, 11.833 ± 0.533 and 11.187 ± 0.517, respectively. Adhesive failure was most commonly seen in all the groups. The phosphoric acid etching remains a highly effective technique for pre-treating dentin in composite resin restorations. The shear strength of composite resin to the dentin of laser-prepared cavity in primary teeth can be improved by the addition of acid etching.

In-Vitro Investigation of the Shear Bond Strength of Different Orthodontic Adhesives to Enamel.

Background: The shear bond strength (SBS) of orthodontic adhesives to enamel is a critical factor in the success of orthodontic treatment. Various adhesives are available in the market, each with different trade names and claimed properties that could influence their bond strength. Understanding these differences is essential for clinical decision-making. Materials and Methods: In this in-vitro study, 60 freshly extracted human premolars were collected and randomly divided into four groups: Group A (Adhesive X-Trade Name: BondPlus), Group B (Adhesive Y-Trade Name: OrthoBond), Group C (Adhesive Z-Trade Name: PowerBond), and Group D (Control). The enamel surfaces were cleaned, polished, and etched following standard protocols. Orthodontic brackets were bonded to the teeth using the respective adhesives according to the manufacturer's instructions. A universal testing machine was employed to measure the SBS, and the data were analyzed using ANOVA with post-hoc tests. Results: The mean SBS values (MPa) were as follows: Group A = 15.2, Group B = 14.8, Group C = 16.5, and Group D (Control) =10.3. Statistical analysis revealed significant differences among the groups (P < 0.05). Post-hoc tests indicated that Group C exhibited significantly higher SBS compared to the other groups. Conclusion: Our findings suggest that among the orthodontic adhesives tested, PowerBond demonstrated superior shear bond strength to the enamel. However, further research is warranted to explore other aspects of adhesive performance and clinical implications.

Influence of handheld nonthermal plasma on shear bond strength of polyaryletherketone to resin-matrix cement.

Background/purpose: Challenges exist regarding the bonding efficiency of polyaryletherketone (PAEK), a high-performance thermoplastic, attributed to its chemical inertness and hydrophobic surface, hindering effective bonding with resin-matrix cement. This research explored the impact of handheld nonthermal plasma (HNP), under varying operational parameters, on PAEK surface wettability and changes in bonding performance with cement. Materials and methods: Three types of disc-shaped PEAK specimens were prepared, with surface treatments categorized as grinding, airborne-particle abrasion (APB), and HNP. Surface wettability was analyzed using a contact angle analyzer (n = 10). Specimens were bonded with resin cement and subjected to artificial aging tests: distilled water bath (NA), thermocycling, and highly accelerated stress tests (n = 10 for each test). Shear bond strength (SBS) was measured, failure modes were analyzed, and statistical analyses were conducted. Results: The HNP markedly improved PAEK surface wettability, achieving superhydrophilicity (P < 0.05). This effect intensified with extended operation times (30 or 60 s) and reduced elapsed times (<30 s). HNP-treated PAEK exhibited higher SBS than APB (P < 0.05) and maintained bonding durability after artificial aging, particularly in ketone-enriched variants. Failure analysis revealed predominantly adhesive failure under APB-NA treatment, mixture failures under HNP-NA treatment and postaging, but no cohesive failure. Conclusion: The HNP device benefits dental settings by transforming the PAEK surface into superhydrophilic properties, thereby improving PAEK-cement bonding. It significantly enhances bond durability within 30 s of operation and after a 30 s elapsed period. It is noteworthy that ketone-enriched PAEK demonstrates markedly improved bonding performance.

Effects of self-etch adhesive agitation with diode laser on dentin bond strength.

The present study assessed the effect of active application of self-etch adhesives with diode laser irradiation on the shear dentin bond strength. Sixty bovine incisors, each embedded individually in hard plaster blocks, were divided into two groups based on the adhesive system used: Group 1 Adper Easy One and Group 2 Clearfil SE Protect. Based on the application technique of self-etch adhesives, each main group was further divided into three subgroups: passive application, active application with a micro-brush, and active application with a 976-nm diode laser tip (phototherapy active application). Shear bond strength tests were conducted using a universal testing machine and the data were analyzed by two-way ANOVA. Post hoc multiple comparisons were performed with the Tukey HSD test. Additionally, the statistical analysis of failure mode distribution was carried out using the chi-squared test (p < 0.05). While the adhesive system exhibited significant differences in shear dentin bond strengths, there were no significant differences in application techniques. Regardless of the application technique, Clearfil SE Protect demonstrated significantly higher dentin bond strength than Adper Easy One. In the present study, the utilization of phototherapy through a 976-nm diode laser for the active application of the tested self-etch adhesives demonstrated similar initial dentin bond strengths to conventional application methods.

Acid Etching's Effect on Hypomineralized Teeth's Bond Strength and Enamel Surface Structure.

The current study evaluated the bracket bond strength of hypomineralized teeth with and without acid etching. Twenty premolar teeth extracted for orthodontic purposes were used in this study. Hypomineralization was induced in all experimental teeth using a cariogenic solution. Then the teeth were divided into two groups. In the first group, orthodontic brackets were bonded by orthodontic adhesive (Green Gloo, Ormco, USA) without etching, while in the second group, further etching was used before bonding. All specimens were examined for morphological changes in the enamel surface after demineralization and debonding using a scanning electron microscope. The shear bond strength was also measured, and the recorded values of bond strengths were collected and statistically analyzed. All massed results were statistically evaluated via an independent t-test to equate Group 1 (G1) and Group 2 (G2). A p-value of < 0.05 is deemed to be statistically substantial. The shear bond strength of groups interacted by orthodontic adhesive with etching (Group 2) was considerably greater than that of groups bonded by orthodontic adhesive without etching. The etching indicates considerably greater tackiness rates compared to bonding without etching, although it leaves more destructed cores, which may need further treatment.

Survival rate, bond, and fracture strength of laminate veneers bonded to different tooth substrates: A systematic review of in vitro studies.

PURPOSE: This study aimed to evaluate how different tooth substrates affect the survival rate, shear bond strength, fracture strength, and mode of failure of laminate veneers (LVs). METHODS: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. In vitro studies comparing the bonding of laminate veneers to different substrates were included. Electronic databases and manual searches were performed to identify relevant studies. Data on survival rate, shear bond strength, fracture strength, and failure modes were extracted and analyzed using Review Manager software. RESULTS: A total of 10 studies were included in the review, comprising 621 laminate veneers. The findings revealed that laminate veneers bonded to enamel substrate had lower failure rates than those bonded to tooth substrate with severely exposed dentin or existing composite restorations (ECRs). The failure modes observed were debonding, chipping, cracks, or fractures. CONCLUSIONS: Bonding laminate veneers to enamel substrate showed higher survival rates compared to bonding to tooth substrates with severely exposed dentin or ECRs, underscoring the significance of enamel preservation. When dealing with exposed dentine surfaces or ECRs, it is crucial to perform appropriate surface treatment before luting to improve adhesion. This involves immediate dentine sealing, as well as the use of suitable primers and bonding agents.

Improving the Mechanical Properties of Glass Ionomer Cement With Nanocrystalline Cellulose From Rice Husk.

This study aimed to evaluate the effect of incorporating nanocrystalline cellulose (NCC) sourced from rice husk on the mechanical properties of a commercial glass ionomer cement (GIC). NCC was isolated through acid hydrolysis, and its crystallinity, chemical structure, and morphology were characterized through x-ray diffractometry, Fourier-transform infrared spectroscopy, and transmission electron microscopy, respectively. Various concentrations of NCC (0%, 0.5%, 1%, and 1.5%) were added to reinforce the GIC matrix. Mechanical tests including compressive strength, flexural strength, hardness, and shear bond strength were conducted on the modified GIC samples. The addition of NCC resulted in increased hardness and shear bond strength values, with 1% NCC showing the highest values compared to other concentrations. However, there was no significant improvement observed in the compressive and flexural strength of the modified GIC. Failure mode test revealed a reduction in adhesive failure with the addition of NCC. Incorporating small amounts of NCC (0.5%-1%) suggests a promising and affordable modification of GIC restorative material using biomass residue, resulting in improved mechanical properties.

Long-Term Bonding Performance of One-Bottle vs. Two-Bottle Bonding Agents to Lithium Disilicate Ceramics.

The aim of this study was to compare the long-term bonding performance to lithium disilicate (LDS) ceramic between one-bottle and two-bottle bonding agents. Bonding performance was investigated under these LDS pretreatment conditions: with hydrofluoric acid (HF) only, without HF, with a two-bottle bonding agent (Tokuyama Universal Bond II) only. Shear bond strengths between LDS and nine resin cements (both self-adhesive and conventional adhesive types) were measured at three time periods: after one-day water storage (Base), and after 5000 and 20,000 thermocycles (TC 5k and TC 20k respectively). Difference in degradation between one- and two-bottle bonding agents containing the silane coupling agent was compared by high-performance liquid chromatography. With HF pretreatment, bond strengths were not significantly different among the three time periods for each resin cement. Without HF, ESTECEM II and Super-Bond Universal showed significantly higher values than others at TC 5k and TC 20k when treated with the recommended bonding agents, especially at TC 20k. Difference in degradation between one- and two-bottle bonding agents containing the silane coupling agent was compared by high-performance liquid chromatography (HPLC). For both cements, these values at TC 20k were also not significantly different from pretreatment with only Tokuyama Universal Bond II. For LDS, long-term bond durability could be maintained by pretreatment with Tokuyama Universal Bond II instead of the hazardous HF.

Comparative analysis of shear bond strength of MTA and Theracal PT with different restorative materials.

BACKGROUND: This study aimed to compare the in vitro shear bond strength (SBS) of mineral trioxide aggregate (MTA) and dual-cured, resin-modified calcium silicate material (Theracal PT) to composite resin, compomer, and bulk-fill composite, and to evaluate the bond failure mode under a stereomicroscope. METHODS: Ninety acrylic specimens, each with a 4 mm diameter and 2 mm height central hole, were prepared. These specimens were randomly divided into two groups based on the capping materials: MTA and Theracal PT. Each group was further subdivided into three subgroups (n = 15) according to the restorative materials: composite resin, compomer, and bulk-fill composite. The specimens were then subjected to shear testing using a universal testing machine at a crosshead speed of 1 mm/min. Post-test, the fracture locations were examined using a stereomicroscope. Data were analyzed using a two-way analysis of variance (ANOVA) and the Tukey test. RESULTS: The SBS values for the Theracal PT group were significantly higher than those for the MTA group (p < 0.001). Within the MTA groups, no significant differences were observed in SBS values across the different restorative materials. However, a significant difference was found between the mean SBS values of the Theracal PT + composite resin group and the Theracal PT + compomer group (p < 0.001). CONCLUSIONS: Theracal PT shows promise in dentistry due to its superior bond strength. Given its bond values, Theracal PT appears capable of forming durable and long-lasting restorations by establishing reliable bonds with various restorative materials commonly used in dentistry.

Carbon nanotube-modified adhesive to caries affected dentin conditioned with Nd: YAP laser, phosphoric acid, and photoactivated-erythrosine.

AIM: Dentin conditioned with phosphoric acid (PA) Nd: YAP laser, and photoactivated-Ery(Erythrosine) on microleakage, shear bond strength (SBS) degree of conversion (DC), and rheological assessment of adhesive-infused with carbon nanotubes (CNTs). MATERIAL AND METHOD: Carious ninety-six human mandibular molars were included. Specimens were disinfected and allocated into three groups based on surface pretreatment (n = 32) Group 1 (PA), Group 2 (Nd: YAP) laser, and Group 3 (Photoactivated-Ery). Conditioned groups were further divided into two 2 subgroups based on the application of unmodified ERA and CNTs-modified ERA. Composite restorations were placed on the CAD surface and thermal aging of the samples was performed. The microleakage assessment was conducted using a dye penetration test. Universal testing machine (UTM) assessed SBS bond failure was evaluated using a stereomicroscope. Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analyses of CNT, and Fourier Transform Infrared FTIR of adhesives were performed. One-way ANOVA and Tukey post hoc analyzed the outcomes. RESULTS: Group 1B samples (PA+ CNTs modified adhesive) presented the minimum marginal leakage and highest bond integrity. Group 2A (Nd:YAP laser+Unmodified adhesive) displayed the maximum scores of microleakage and lowest bond strength. CONCLUSION: Photoactivated Ery-PS can serve as an alternative to phosphoric acid for conditioning CAD. Incorporating CNT in adhesive significantly enhanced bond integrity and marginal seal with no significant difference in DC.