Adhesion durability of dual-cure resin cements and acid–base resistant zone formation on human dentin

Effect of acid-etching solution on surface properties, crystallography, and shear bond strength of ultra-translucent zirconia to enamel

Ultra-translucent zirconia has gained popularity in restorative dentistry due to its excellent esthetic properties and high strength. Surface treatment methods play a crucial role in optimizing the bond between zirconia and enamel. This laboratory study aimed to investigate the influence of acid-etching solution on the surface properties of ultra-translucent zirconia and its subsequent shear bond strength to enamel. Thirty-six ultra-translucent zirconia disks were divided into three groups (n = 12): as-sintered (C) as the control group, airborne-particle-abraded (AB), and acid-etched with Zircos-E™ etching solution (ZE). Surface topography, roughness, and phase composition were assessed using scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and X-Ray diffraction analysis (XRD), respectively. The remaining disks were bonded to enamel using resin cement, and shear bond strength (SBS) was tested after 10,000 thermo-cycles between 5℃ and 55℃. Data were statistically analyzed using one-way ANOVA (α = 0.05). ZE induced higher surface roughness compared to AB, with a more stable crystalline structure. ZE group exhibited the highest SBS (22.48 ± 2.97 MPa), followed by AB (16.72 ± 2.52 MPa), while C group had the lowest SBS (7.55 ± 2.73 MPa). ZE solution demonstrated enhanced surface properties and higher shear bond strengths to human enamel compared to conventional airborne-particle abrasion. This finding highlights the potential of acid-etching solutions in improving the bond between ultra-translucent zirconia and enamel in restorative dentistry applications.

Evaluation of long-term bond strength and mechanical properties of a recently launched light-cure resin cement for veneer cementation

OBJECTIVES

This study aimed to evaluate the initial and six-month bonding performance and mechanical properties of a recently launched light-cure resin cement compared to light-cure, dual-cure resin cements, and resin composite used for veneer cementation.

MATERIALS AND METHODS

Four luting cements-Panavia Veneer LC (PVL), Variolink Esthetic LC (VEL), Panavia V5 (PV5), and Clearfil AP-X (APX)-were tested for microtensile bond strength (μTBS), Knoop hardness (KHN), degree of conversion (DC), and ultimate tensile strength (UTS) at 24-hour and 6-month. All values were subjected to statistical analysis (α = 0.05). Fracture mode and resin-dentin interfaces were observed via SEM.

RESULTS

One-way ANOVA revealed significant differences among the materials for each measured property at 24-hour and 6-month (p < 0.001). The PVL group demonstrated superior bond strength at both time points (24-hour: 58.72 MPa; 6-month: 59.13 MPa), comparable to APX. In contrast, the VEL group showed a significant decrease in μTBS from 24-hour (27.62 MPa) to 6-month (10.65 MPa) (p < 0.001). The dual-cure cement PV5 showed marked improvements in μTBS and mechanical properties beyond 24 h (p < 0.001). KHN and UTS were highest in APX. PVL and APX had higher DC values than VEL and PV5. SEM revealed variations in resin-dentin interfaces across the groups.

CONCLUSIONS

PVL demonstrated reliable and durable bonding performance, while PV5 showed improvements after 24 h, suggesting the need for extended curing time for optimal performance.

CLINICAL RELEVANCE

PVL provides durable bonding and mechanical performance, making it a promising option for veneer cementation in clinical practice.

The influence of phosphoric acid and primer treatment on the evaluation of the adhesive resin cement/enamel interface

This study evaluated the influence of phosphoric acid and primer on enamel bonding performance using Panavia V5. Ground bovine enamels were assigned: using K-etchant syringe and Tooth Primer (CT), using K-etchant syringe (PA), using Tooth Primer (TP), neither K-etchant syringe nor Tooth Primer was used (NC). The micro-tensile bond strength values of CT and PA were significantly higher than TP. After thermal cycling, the values were higher in CT and PA. In the leakage test, line-shaped signal pattern at the adhesive interface was detected in NC, and the signal was partially detected in PA and TP. Observation of the adhesive interface after acid and base challenge confirmed tooth-like structures in groups except NC. Large spaces were observed between the enamel and cement in NC. Limited in this study, the lack of application of phosphoric acid or Tooth Primer may affect the enamel bonding performance.

Comparative bonding performance of coronal dentin disks and CAD/CAM resin composite disks for biological restoration: The impact of resin-coating technique

This study evaluated the bonding performance of coronal dentin disks, designed for biological restoration, and CAD/CAM resin composite disks when bonded to flat dentin surfaces using dual-cure resin cements, with and without a resin-coating (RC) technique. Three distinct groups were established within the non-RC group, each using one of the two types of resin cements in a self-adhesive mode: one-step self-etch adhesive (1-SEA) without light-cure, 1-SEA with light-cure, and a separate group using an alternate cement. Within the RC group, a subgroup was established for each cement. The microtensile bond strength (μTBS) of the disk-dentin beam was tested after 0 and 10,000 thermocycles in a 5°C/55°C. No significant μTBS difference was observed among the non-RC groups. However, when using RC, the μTBSs of coronal dentin disks significantly exceeded those of CAD/CAM resin composite disks. Thermocycle aging did not affect μTBS in any of the bonding methods, except in self-adhesive mode.

Assessment of Degree of Conversion and Volumetric Shrinkage of Novel Self-Adhesive Cement

The degree of monomer conversion and polymerization shrinkage are two of the main reasons for potential adhesion failure between the tooth structure and the restoration substrate. To evaluate the degree of conversion and polymerization shrinkage of a newly developed self-adhesive resin cement, the degree of conversion (DC) was measured using FTIR under different activation modes, temperatures, and times. Volumetric shrinkage was tested using the AcuVol video imaging method. The experimental cement showed a higher DC than other cements under self-curing. The DC of the experimental cement was higher than that of other cements, except SpeedCem Plus under light curing. The experimental cement had a higher DC than other cements, except SpeedCem Plus in some conditions under dual curing. All self-adhesive cements had a higher DC at 37 °C than at 23 °C under self-curing, and there was no statistical difference between 23 °C and 37 °C under light curing. All self-adhesive cements showed a significantly higher DC at 10 min than at 5 min under self-curing. There was no statistical difference between 5 min and 10 min for most cements under dual curing. All self-adhesive cements statistically had the same volumetric shrinkage under light curing and self-curing. The newly developed self-adhesive resin cement exhibited a higher degree of conversion and similar volumetric shrinkage compared to these commercial self-adhesive resin cements.

Dental Resin-Based Luting Materials-Review

As cementation represents the last stage of the work involved in making various indirect restorations (metal ceramic crowns and bridges, full ceramic crowns and bridges, inlays, onlays, and fiber posts), its quality significantly contributes to the clinical success of the therapy performed. In the last two decades, the demand for ceramic indirect restorations in everyday dental practice has considerably increased primarily due to the growing significance of esthetics among patients, but also as a result of hypersensitivity reactions to dental alloys in some individuals. In this context, it is essential to ensure a permanent and reliable adhesive bond between the indirect restoration and the tooth structure, as this is the key to the success of aesthetic restorations. Resin-based luting materials benefit from excellent optical (aesthetic) and mechanical properties, as well as from providing a strong and durable adhesive bond between the restoration and the tooth. For this reason, resin cements are a reliable choice of material for cementing polycrystalline ceramic restorations. The current dental material market offers a wide range of resin cement with diverse and continually advancing properties. In response, we wish to note that the interest in the properties of resin-based cements among clinicians has existed for many years. Yet, despite extensive research on the subject and the resulting continued improvements in the quality of these materials, there is still no ideal resin-based cement on the market. The manuscript authors were guided by this fact when writing the article content, as the aim was to provide a concise overview of the composition, properties, and current trends, as well as some future guidelines for research in this field that would be beneficial for dental practitioners as well as the scientific community. It is extremely important to provide reliable and succinct information and guidelines for resin luting materials for dental dental practitioners.

Effect of Temporary Cement, Surface Pretreatment and Tooth Area on the Bond Strength of Adhesively Cemented Ceramic Overlays-An In Vitro Study

Several viewpoints have been reported regarding the effect of temporary cements, different surface pretreatment protocols before adhesive cementation, and predictive factors. This in vitro study tested if temporary cement, pretreatment of the tooth surface, the size of enamel or dentine influence adhesive cementation to zirconia ceramics. Twenty premolars were prepared for determination of enamel and dentin area, bond strength test and failure analysis. The samples were divided into two groups: untreated prior adhesive cementation (n = 10) and with temporary cementation done, pretreated prior adhesive cementation (n = 10). Zirconia overlays (Katana Zirconia STML) were cemented on the grounded flat teeth surfaces using Panavia V5. An additional six premolars underwent dentine tubule analysis with SEM to detect temporary cement residues after temporary cementation on an untreated tooth surface (n = 3) and on a pretreated surface (n = 3). The independent sample t-test was used to compare the two groups and the means of the total tooth, dentin or enamel areas did not differ significantly between the untreated and pretreated specimens. The mean tensile bond strength was significantly (p = 0.005) higher in the pretreated specimens (337N) than in the untreated ones (204N). The overall multivariable linear regression model with three predictors (surface pre-treatment, enamel area and dentine area) was significant (p = 0.003), among which the size of enamel was the strongest predictor (β = 0.506; p = 0.049), followed by the pretreatment effect (β = 0.478; p = 0.001) and the size of dentin area (β = -0.105; p = 0.022).

Update on Dental Luting Materials

A dental luting material aids in the retention and stability of indirect restorations on the prepared tooth structure. In dentistry, clinicians are using a wide range of luting materials for the cementation of indirect restorations. Zinc oxide eugenol and non-eugenol cements, zinc phosphate cement, zinc polycarboxylate cement, glass ionomer cement and resin cements are common dental cements used in dentistry. Each luting material or cement possesses unique properties and clinical implications. An ideal luting cement should be biocompatible, insoluble, resistant to thermal and chemical assaults, antibacterial, aesthetic, simple and easy to use. It should have high strength properties under tension, shear and compression to resist stress at the restoration-tooth interface, as well as adequate working and setting times. So far, no luting material possesses all of these properties of an ideal cement. Scientists have been modifying the conventional luting cements to improve the material's clinical performance and developing novel materials for clinical use. To achieve the best clinical outcome, clinicians should update their knowledge and gain a good understanding of the luting materials so that they can make a wise clinical decision on the material selection and obtain an insight into the development of luting cements. Therefore, the objective of this study is to provide a discussion on the physical, chemical, adhesive and aesthetic properties of common luting materials. The clinical indications of these luting materials are suggested based on their properties. In addition, overviews of the modification of the conventional luting materials and the newly developed luting materials are provided.

Effect of adhesive strategy on resin cement bonding to dentin

OBJECTIVE

The cement bonding strategy and the polymerization mode can influence the prognosis of indirect restorations. The microtensile bond strength (μTBS) and dentin endogenous enzymatic activity of a dual-cure resin cement (PV5) used in combination with two dentin surface conditioners (accelerator-enhancer primer, TP or universal adhesive, UA) were evaluated.

MATERIALS AND METHODS

PV5 was used to lute composite overlays after dentin treatment with TP or UA. The resin cement was self-cured, SC (1 h at 37 °C) or dual-cured, DC (20 s light-cure followed by 15 min self-cure at 37°C). The μTBS test, fractographic analysis, and the in situ zymography evaluations were performed after 24 h (T₀ ) or 1 yr (T₁₂ ) of artificial storage. Data were statistically analyzed (α = 0.05).

RESULTS

TP/DC obtained the highest adhesive strengths (45 ± 9 and 36.6 ± 8), while UA/SC (17 ± 8 and 11 ± 4) the lowest, both at T₀ and T₁₂ , respectively. DC resulted in superior bonding values than the SC, independent of the dentin surface treatment (p < 0.05). The type of adhesive, curing mode and aging influenced the gelatinolytic activity (p < 0.05).

CONCLUSIONS

The dual-cure resin cement used in combination with its accelerator-enhancer primer showed superior bonding performances with respect to universal adhesive. Dual-curing the resin cement was determinant to enhance bonding capability over time, independent of the adhesive strategy.

CLINICAL RELEVANCE

Clinicians must be aware to faithfully follow manufacturer's recommendation regarding the adhesive strategy suggested with the resin cement used.

Influence of Novel Experimental Light-Cured Resin Cement on Microtensile Bond Strength

The purpose of this study was to evaluate the microtensile bond strength (µTBS) and Knoop hardness number (KHN) of a novel experimental light-cured resin cement (HL). Eighteen flat dentin surfaces of human molars were polished using #600 SiC paper and bonded to CAD/CAM resin blocks with the respective resin cements and composites: HL, Panavia V5 (PV), and Clearfil AP-X (AP). All specimens were stored in distilled water at 37 °C for 24 h and 7 days. Scanning electron microscope (SEM) and energy dispersive X-ray (EDX) observations were performed to evaluate filler morphology and to detect the elements. The resin cements had a significant effect on the immediate µTBS (F = 22.59, p < 0.05) and after water storage µTBS (F = 22.83, p < 0.05). Significant differences (p < 0.05) in the KHN between the tested materials were observed, and HL indicated the highest KHN when compared with PV. HL showed a combination of the regular-shaped filler and spherical-shaped filler within the matrix. Silicon was detected in HL from the EDX evaluation. HL exhibited better bonding performance and polymerization, which may have contributed to the improvement of the adhesive strength.

The roles of 10-methacryloyloxydecyl dihydrogen phosphate and its calcium salt in preserving the adhesive-dentin hybrid layer

OBJECTIVES

10-Methacryloyloxydecyl dihydrogen phosphate (MDP) has been regarded as the most effective dentin-bonding monomer for more than 20 years. Although the dentin-bonding promoting effect of MDP has been well demonstrated, the mechanisms by which it benefits the stably of collagen within the adhesive-dentin hybrid layer are not currently fully understood. The objective of this study was to investigate the roles of MDP and its calcium salt in preserving the adhesive-dentin hybrid layer.

METHODS

MDP-conditioned collagen was investigated by Fourier-transform infrared spectroscopy, Ultraviolet-visible spectroscopy, and molecular docking. The structural changes to the dentin surface upon acid-etching and MDP-conditioning were observed by SEM. X-ray diffraction and nuclear magnetic resonance were used to investigate the chemical interactions between MDP and HAp. The collagen-protecting effects of MDP and its Ca salt were investigated using in-situ zymography, rhMMP-9 colorimetric assay, hydroxyproline assay, and molecular docking.

RESULTS

MDP forms a stable collagen-phosphate complex through hydrogen bonding with the collagen in dentin. Furthermore, it generates MDP-Ca salts that are deposited on the dentin collagen scaffold, protecting it from degradation. Moreover, both free MDP and the MDP-Ca salt inhibit matrix metallopeptidase and exogenous proteases, with the inhibitory effect of the calcium salt being significantly stronger than that of the free form.

SIGNIFICANCE

MDP-based adhesives preserve the collagen within the hybrid layer by simultaneously improving collagen's resistance to exogenous enzymes and inhibiting MMP activity, both of which contribute to the longevity of dentin-resin bonding.

Retention strength of monolithic zirconia crowns cemented with different primer-cement systems

BACKGROUND

The purpose of this in vitro study was to assess the influence of different cement systems with different ceramic primers on the retention strength of zirconia crowns.

METHODS

Thirty extracted molars were prepared with flat occlusal surfaces, 20 degrees taper, and 3 mm axial wall height. A zirconia crown with an occlusal bar was fabricated for each tooth. All specimens were divided (n = 10) into; Group M: Multilink Speed/Monobond N, Group P: Panavia V5/Clearfil Ceramic Primer Plus, Group D: Duo-Link universal/Z-Prime Plus. The intaglio surfaces of crowns were air-abraded using 50 µm alumina at 2.5 bar for 10 s. Then each crown was cemented onto its corresponding tooth. All specimens were thermocycled for 10,000 cycles between 5 and 55 °C. Each crown was subjected to gradually increasing vertical load along the path of insertion through hooks engaging the occlusal bar using a universal testing machine until failure. The force at dislodgment was recorded and retention strength was calculated for each specimen. The failure modes were recorded for each specimen. The data were statistically analyzed using one way ANOVA test followed by Tukey HSD test (α = .05).

RESULTS

Group D showed lowest strength (1.42 ± 0.23 MPa) and differed significantly (P < .001) from Group M (2.71 ± 0.45 MPa) and Group P (2.47 ± 0.41 MPa). There was no significant difference (P = .34) between Group M and Group P. The failure modes for Groups M and Group P were mainly cohesive, while Group D showed adhesive failure.

CONCLUSIONS

The retention strength of zirconia crowns was improved with Multilink Speed and Panavia V5 cement systems, while the use of the Duo-Link Universal cement system only showed half of those retention strength values.

Influence of curing modes on conversion and shrinkage of dual-cure resin-cements

OBJECTIVE

To explore the effect of curing modes of dual-cure resin cements on their degree of conversion (DC) and polymerization shrinkage (PS) over specific post-activation periods.

METHODS

Five self-adhesive (PANAVIA SA, RelyX Universal Resin, RelyX Unicem 2, Bifix SE, and SpeedCEM Plus) and three conventional (PANAVIA V5, Nexus Third Generation, and RelyX Ultimate Universal) dual-cure resin cements were studied. Four specimens (n = 4) were made per curing mode (light/self-cure) to measure either DC or PS. FTIR was utilized to measure real-time DC (%) over 24 h. The Bonded Disk method was used to measure shrinkage at 23 °C over 1 h. The data were analyzed using one-way ANOVA, Tukey post-hoc tests and independent/ paired sample t-tests (a = 0.05).

RESULTS

After 1 h post-activation, the DC of light-cured (LC) specimens ranged between 66.6% and 77.4%, whereas for self-cured (SC) specimens DC ranged between 44.4% and 73.2%. After 24 h, the DC of LC specimens ranged between 74.8% and 82.4% and between 62.7% and 81.7% for SC specimens. After 24 h, the DC of three cements (BSE, PV5, and RXU) were comparable between their curing modes (p > 0.05), whereas five cements (CEM, NX3, PSA, RXU2, RXL) had significantly lower DC for SC compared to LC specimens (p < 0.05). After 1 h post-activation, shrinkage ranged between 5.9% and 8.5% for LC and between 4.9% and 8.3% for SC specimens. Most cements were not significantly different between curing modes. However, light-cured PAS, RXL and RXU2 had significantly higher shrinkage (p < 0.05). After 1 h post-activation, a strong positive correlation existed between conversion and shrinkage (LC: r² = 0.95 and SC: r² = 0.93).

SIGNIFICANCE

Whenever light access is possible, light-curing of resin-cements remains beneficial to the overall efficacy of their conversion and thus all factors that depend on that. Conversion and shrinkage behavior are intrinsically important factors in clinical selection of resin-cement products.

Influence of the activation mode on long-term bond strength and endogenous enzymatic activity of dual-cure resin cements

Objective

To investigate the long-term microtensile bond strength (µTBS), interfacial nanoleakage expression (NL), and adhesive stability of dual-cure resin cements with/out light activation to dentin.

Materials and methods

Composite overlays (N = 20) were luted to deep dentin surfaces with RelyX Ultimate (RXU, 3M) or Variolink EstheticDC (VAR, Ivoclar-Vivadent). A universal adhesive was used for bonding procedures (iBond universal, Heraeus Kulzer). The resin cements were either self-cured (SC; 1 h at 37 °C) or dual-cured (DC; 20s light-cure followed by 15 min self-cure at 37 °C). Specimens were submitted to µTBS immediately (T₀) or after 1 year of laboratory storage (T₁₂). The fracture pattern was evaluated using scanning electron microscopy (SEM). Data were statistically analyzed with two-way ANOVA/Tukey test. Further, the NL was quantified and analyzed (chi-square test) and in situ zymography was performed to evaluate the endogenous enzymatic activity within the hybrid layer (HL) at T₀ and T₁₂ (Mann–Whitney test)_. The significance level for all statistical tests was set at p = 0.05.

Results

DC resulted in higher bond strength and decreased fluorescence at the adhesive interface, irrespective of the material and the storage period (p < 0.05). Significantly lower bonding performances (p < 0.05) and higher endogenous enzymatic activity (p < 0.05) were observed within the HL at T₁₂ compared to T₀ in all tested groups.

Conclusions

Light-curing the dual-cure resin cements, more than the cement materials, accounted for good bonding performances and higher HL stability over time when used with a universal adhesive.

Clinical significance

The curing condition influences the bonding performances of dual-cure resin cements to dentin when used with a universal adhesive.

Touch-Cure Polymerization at the Composite Cement-Dentin Interface

Ceramic restorations are often adhesively luted onto the tooth prep. The so-called touch-cure concept was developed to yield optimum polymerization of composite cement at the restoration-cement-tooth interface for immediate bond stabilization. Although this touch cure is theorized to initiate polymerization at the interface when the accelerator in the primer makes contact with the cement, this process has not yet been proven. This study aimed to elucidate the mechanism of touch cure by measuring the degree of conversion (DC) of composite cement applied with or without an accelerator-containing tooth primer (TP) versus an accelerator-free primer using real-time Fourier-transform infrared spectroscopy (RT-FTIR) and attenuated total reflection (ATR)-FTIR. Interfacial bond strength was measured in shear mode, the accelerator composition confirmed by X-ray fluorescence analysis (XRF), and the interfacial interaction of TP and composite cement with dentin investigated by X-ray diffraction (XRD), focused-ion-beam scanning electron microscopy (FIB-SEM) with 3-dimensional interface reconstruction, and transmission electron microscopy (TEM). RT/ATR-FTIR revealed the significantly highest DC when the composite cement was applied with the accelerator-containing primer. XRF disclosed a vanadium compound as a novel chemical accelerator within TP, instead of a classic chemical curing initiator system, to set off touch cure as soon the cement contacts the previously applied primer. Although the TP contains the acidic functional monomer 10-MDP for adhesion to tooth tissue, touch cure using the accelerator-containing TP combined the fastest/highest DC with the highest bond strength. FIB-SEM and TEM confirmed the tight interfacial interaction at dentin with submicron hybridization along with stable 10-MDP also Ca-salt nanolayering.

Comparison of different etch-and-rinse adhesive systems based on shear fatigue dentin bond strength and morphological features the interface

OBJECTIVES

The aim of this study was to investigate dentin bonding durability of different etch-and-rinse (ER) adhesive systems under fatigue stress and to compare morphological features of resin/dentin interfaces using SEM.

METHODS

Two three-step ER adhesives, a two-step ER adhesive, and a universal adhesive in ER mode were evaluated. Before application of either primer or adhesive, phosphoric acid etching of human dentin was completed. Fifteen bonded specimens for each adhesive system were stored in distilled water at 37 °C for 24 h, then subjected to a shear bond strength (SBS) test. Bonding durability was assessed from the perspective of biomechanical stress. 25 bonded specimens for each adhesive system were subjected to shear fatigue strength (SFS) testing with a repeated subcritical load at a frequency of 20 Hz for 50,000 cycles or until failure.

RESULTS

Mean SBS and SFS values ranged from 33.3 to 41.2 MPa, and from 18.3 to 20.3 MPa, respectively. Three-step adhesives showed higher SBS and SFS values than the other adhesive systems. Under SEM, resin tags in different adhesive systems showed similar features, but morphology below the hybrid layer was material dependent. The universal adhesive in ER mode showed an obvious thin, high-density reaction layer below the hybrid layer.

SIGNIFICANCE

Three-step adhesives showed higher dentin bond durability than the other ER adhesives; no significant differences in SFS were found between the universal adhesive in ER mode and the three-step ER adhesives. The results of this in vitro study indicate that some ER adhesives might establish chemical bonding with intact dentin below the hybrid layer in addition to micromechanical retention.

Ultra-morphological studies on enamel-universal adhesive interface

OBJECTIVES

Nowadays, the universal adhesives are often used for silane application prior to application of self-adhesive resin cements. The purpose of this study was to evaluate enamel surface roughness and to observe the enamel-adhesive interface after acid-base challenge using three different self-adhesive resin cements combined with universal adhesives.

MATERIALS AND METHODS

Three self-adhesive resin cements: PANAVIA SA Luting Cement Plus (SA), Calibra Universal (CA) and MaxCem Elite Chroma (MC) which in conjunction with the particular universal adhesives: Clearfil Universal Bond Quick (UQ), Prime&Bond Universal (PB) and Optibond Universal (OB) were tested. Thirty enamel surfaces from caries-free human premolars were ground and bonded with the tested self-adhesive resin cements combined with universal adhesives. The surface roughness test (Sa) with or without applying adhesives was performed with 3D-CLSM. The interface of the bonded specimens after acid-base challenge was also examined by SEM.

RESULTS

The Sa of OB was significantly higher than those of PB and UQ. There were statistically significant differences among all of the groups (p < 0.05). An acid-base resistant zone (ABRZ) was observed in all groups, however, formation of the ABRZ was material dependent.

CONCLUSION

OB provided most etching performance to enamel of human premolars and MC group with OB presented durability against acid-base challenge.

CLINICAL SIGNIFICANCE

Nowadays, the combination of self-adhesive resin cement and universal adhesive may be a viable option for a reliable bonding performance and bonding durability in indirect restorative dentistry.

Comparison of the Effect of Proanthocyanidin Surface Treatments on Shear Bond Strength of Different Cements

This study aimed to compare the effect of proanthocyanidin-rich grape seed extract (Pa-rich GSE) in two different concentrations on the bond strength to dentin tissue for four different cement groups (resin cement (P), resin modified glass ionomer cement (K), calcium aluminate glass ionomer cement (C), glass ionomer cement (G)). One hundred and eighty dentin surfaces of the extracted molar teeth placed on acrylic cylinders were divided into 12 groups randomly (n = 15). Each cement group was further divided into control (CP, CC, CK, CG), 6.5% Pa-rich GSE (P6.5, C6.5, K6.5, G6.5) and 12.5% Pa-rich GSE (P12.5, C12.5, K12.5, G12.5) subgroups. In accordance with the manufacturer’s recommendations the cements were applied. After shear bond tests, surfaces were examined under a stereomicroscope. Median shear bond strength (in MPa) of CP, CK, CC, CG groups were 14.13, 7.05, 4.87, 3.86; for the P6.5, G6.5, C6.5, K6.5 groups they were 13.98, 13.42, 6.21, 3.27; and for the P12.5, C12.5, K12.5, G12.5 groups they were 15.08, 5.40, 3.10, 0.00, respectively. CK and K6.5 groups showed a significant difference from the K12.5 group (p < 0.05). Also, CG, G6.5 and G12.5 groups were found statistically different from each other (p < 0.05). Applied to the dentin surface, 6.5% Pa-rich GSE enhanced the bond strength of glass ionomer cements.