Shear Bond Strength Test Research Articles

Adhesive Cementation of CAD/CAM Silica-based Ceramics: Effect of Adhesive Type and Long-term Aging on the Bond Strength to Composite Cement.

To investigate the effect of adhesive type and long-term aging on the shear bond strength (SBS) between silica-based ceramics and composite cement (CC). Lithium-silicate (LS), feldspathic (FD) and polymer-infiltrated ceramic (PIC) blocks were sectioned (10 x 12 x 2 mm) and divided into 24 groups considering the factors: "ceramics" (LS, FD, and PIC), "adhesive" (Ctrl: without adhesive; 2SC: 2-step conventional; 3SC: 3-step conventional; 1SU: 1-step universal), and "aging" (non-aged or aged [A]). After the surface treatments, CC cylinders (n = 15, Ø = 2 mm; height = 2 mm) were made and half of the samples were subjected to thermocycling (10,000) and stored in water at 37°C for 18 months. The samples were submitted to SBS testing (100 kgf, 1 mm/min) and failure analysis. Extra samples were prepared for microscopic analysis of the adhesive interface. SBS (MPa) data was analyzed by 3-way ANOVA and Tukey's test (5%). Weibull analysis was performed on the SBS data. All factors and interactions were significant for SBS (p<0.05). Before aging, there was no significant difference between the tested groups and the respective control groups. After aging, the LS_1SU (22.18 ± 7.74) and LS_2SC (17.32 ± 5.86) groups exhibited significantly lower SBS than did the LS_Ctrl (30.30 ± 6.11). Only the LS_1SU group showed a significant decrease in SBS after aging vs without aging. The LS_1SU (12.20) group showed the highest Weibull modulus, which was significantly higher than LS_2SC_A (2.82) and LS_1SU_A (3.15) groups. No type of adhesive applied after silane benefitted the long-term adhesion of silica-based ceramics to CC in comparison to the groups without adhesive.

Effect of Surface Treatment and Resin Cement on the Bond Strength of an Advanced Lithium Disilicate.

The aim of the study was to evaluate the effect of surface treatment and resin cement on the bond strength of conventional and advanced lithium disilicates (ALDs). Ceramic slices (2 × 13 × 15 mm) of conventional lithium disilicate (LD) (IPS e.max CAD) and ALD (CEREC Tessera) were sectioned, polished, and divided into 16 groups (n = 10) according to the factors: ceramic, surface treatment, and resin cement (Panavia V5 and Variolink Esthetic DC). Surface treatments consisted of hydrofluoric acid 4.9% etching for 20 seconds (Hf20) or 30 seconds (Hf30), self-etching ceramic primer (Se), and sandblasting (Sb). Then, a resin cement cylinder (Ø = 2.5 mm) was manufactured on each specimen's surface. The specimens were then submitted to a shear bond strength (SBS) test. Surface roughness was evaluated through a contact profilometer, and surface morphology was evaluated under scanning electron microscopy for qualitative analysis. Two-way analysis of variance (ANOVA) was used to analyze the data of SBS and surface roughness. For bond strength, the effects of surface treatment, resin cement, and the interaction were analyzed for each ceramic. For roughness, analyzed factors include ceramic and surface treatment. ANOVA revealed that ceramic (p = 0.047) and surface treatment (p < 0.001) factors affected the bond strength, while the cements performed similarly. Both materials showed adequate bond strength (ALD 19.1 ± 7.7 MPa; LD 17.1 ± 7.9 MPa). Sb protocol showed the lowest mean value (9.6 ± 2.9 MPa) compared with Hf20 (22.0 ± 7.1 MPa), Hf30 (21.7 ± 7.4 MPa), and Se (19.3 ± 6.0 MPa). For both ceramics, the highest performance was obtained after applying Se and Hf20 or Hf30. Therefore, longer etching time is unnecessary. Sb protocol must be avoided.

Shear bond strength of a RMGIC for orthodontic bracket bonding to enamel

ObjectiveTo evaluate the shear bond strength (SBS) of a restorative resin-modified glass ionomer cement (RMGIC) for orthodontic bracket bonding.Materials and methodsOne hundred twenty-one human teeth were randomly divided into 11 groups (n = 11) according to the surface treatment applied (H3PO4 ± Transbond Plus (TSEP) or Scotchbond Universal (SU)), and the adhesive used (Riva LC HV (RIVA), Fuji Ortho (FUJI), and Transbond XT (TXT)). For each sample, a metal button was bonded. SBS tests were performed at 1 week and debonded specimens were observed for failure modes determination. One-way ANOVA followed by Tukey’s post hoc test was used to compare SBS differences and Fisher’s exact test to analyze the failure modes (p < 0.05).ResultsTSEP + FUJI and H3PO4 + SU + TXT showed the highest SBS values while H3PO4 + TSEP + RIVA showed the lowest value. Cohesive failure and mixed failure were found in the groups with SU and TXT and adhesive failure in the other groups.Discussion/ConclusionsThe bonding of orthodontic attachments to enamel could be performed with any of the three materials studied. The use of a universal adhesive in the bonding protocol could optimize the adhesion values. Clinical studies would be needed to confirm the results obtained.

The impact of CO2 laser on the bond strength of translucent zirconia and traditional zirconia with the resin cement: In vitro study

Background/Aim: The aim of this study is to compare the impact of CO 2 laser on traditional zirconia and translucent zirconia in terms of the bonding strength to resin cement. Material and Methods: In this in-vitro study 20 zirconia disks (10 mm diameter and 2 mm thickness) were assigned to two groups (n = 10). Group 1: 10 discs of traditional zirconia, Group 2: 10 discs of translucent zirconia, CO 2 lasers were used for pretreatment of zirconia surface, respectively. Dentinal disks were cemented on zirconia disk using dual-curing resin cement. Shear bond strength tests were performed at a crosshead speed of 1 mm/min after 24 h distilled water storage. Data was analyzed by T Student's test. Results: The means and standard deviations of shear bond strength values in Group 1, and Group 2 were 1.15, 0.38, 1.99 , 0.65 MPa respectively. Data showed that application of CO 2 laser resulted in a significant higher shear bond strength of resin cement to translucent zirconia ceramics (p &lt; 0.05). Conclusions: Application of CO 2 laser treatment (3W) increases the bond strength to the resin cement of translucent zirconia compared to traditional zirconia.

Do the methods for cleaning the base of brackets used in indirect bonding interfere with adhesion to tooth enamel?

The objective of this study was to evaluate the shear bond strength of metal brackets bonded with indirect bonding, under different surface treatment protocols. 40 bovine teeth were randomly divided into four groups (n = 10), according to the type of surface treatment: G1 = 70% alcohol, G2 = air/water spray, G3 = 100-µm aluminum oxide blasting, G4 = direct boning. After drying, the standard Edgewise central incisor brackets were bonded with light-cured resin. The brackets were moved from the plaster models by means of a transfer tray made with condensation silicone, and bonded to the surface of the enamel with self-curing adhesive. The samples were submitted to shear tests by a universal test machine. Data were analyzed with SPSS 20.0 by the one-way ANOVA test and the Tukey post-test. No statistically significant difference (p=0.174) was observed between the mean forces measured between the group for shear strength values of the groups during the test: G1 (5.33 MPa), G2 (3.52 MPa) and G3 (4.58 MPa). The bracket surface treatment protocols presented similarities in shear bond strength test. However, alcohol 70% and oxide blasting presented higher absolute values of resistance than the water group.

EVALUATION OF BOND STRENGTH BETWEEN DIFFERENT SYSTEMS FOR ADHESIVE CEMENTATION TO FELDSPATHIC PORCELAIN AND ZIRCONIUM OXIDE

Introduction: New systems for adhesive cementation have been increasingly developed and used in daily clinical practice for the cementation of ceramic prostheses. Differences in the chemical composition of various system components can influence the bond strength between the resin cement and the ceramic. Objective: This study aims to evaluate the bond strength between two ceramic systems—feldspathic porcelain and yttria-stabilized zirconium oxide—and three different systems for adhesive cementation: Rely X ARC, Multilink System, and Rely X UCem. Methodology: Thirty discs of Noritake feldspathic porcelain and thirty discs of zirconium oxide ceramic were fabricated, each measuring 7.5 mm in diameter by 3.0 mm in thickness, according to the manufacturers’ instructions. The discs were polished on a mechanical polisher with water sandpaper ranging from 320 to 1500 grit and embedded in ½ inch PVC tubes with self-curing acrylic resin. The feldspathic porcelain discs were conditioned with 10% hydrofluoric acid for 120 seconds, and the zirconium oxide discs were sandblasted with 40 psi alumina for 10 seconds at 10 mm. All discs were then washed and placed in an ultrasonic bath with distilled water for 10 minutes. The cementation systems were applied according to the manufacturers’ instructions (n=10) on an adhesion area of 5.0 mm in diameter, delimited by a tripartite metal matrix. The samples underwent 1,000 thermal cycles ranging from 5°C to 55°C. Shear bond strength tests were performed on an EMIC DL2000 testing machine with a 20 kN load cell and a speed of 0.5 mm/min. The mean values of the groups were as follows (in MPa): Feldspathic with Rely X ARC (G1) 6.21; Feldspathic with Multilink (G2) 8.98; Feldspathic with Rely X UCem (G3) 8.15; Zirconium Oxide with Rely X ARC (G4) 0.53; Zirconium Oxide with Multilink (G5) 9.25; Zirconium Oxide with Rely X UCem (G6) 4.37. Data were subjected to one-way ANOVA and Tukey tests. Results: There was no significant difference among the feldspathic porcelain groups. For zirconium oxide, Multilink showed higher bond strength values. Conclusion: The bond strength between the cements and feldspathic porcelain exceeded the intrinsic strength of this material, and Multilink showed the highest bond strength values regardless of the ceramic material.

Effect of Surface Treatments with Plasma and Chemical Bond on Shear Bond Strength of Acrylic Denture Teeth to Flexible and Heat-Cured Denture Base Material: An In Vitro Study

Introduction: We aimed to evaluate the shear bond strength of acrylic denture teeth to flexible and heat-cured denture base material after surface treatments with argon plasma, chemical bonding agent (PALFIQUE universal), and combination. Methods: A total of 80 incisor acrylic denture teeth were treated with a argonplasma, chemical bond (PALFIQUE universal bond), and a combination with 10 samples for each group. The neck (gingival portion) of teeth was cut at a 45° angle, and the teeth were attached to heat-cured acrylic resin and flexible denture base material. All the specimens were stored in artificial saliva for 7 days in an incubator (37 °C). A shear bond strength test was conducted using an Instron universal testing machine. Data were analyzed by the analysis of variance (ANOVA) and the Tukey’s honest significant difference post hoc test using R 4.2.3. Results: A statistically significant difference was found among study groups regarding the type of base, surface treatment with bond, plasma, and combination of bond and plasma (P &lt; 0.00). The Tukey’s test showed that in a heat-cured base, the difference between the control and surface treatment with bond was not significant (P &gt; 0.05). Also, in the flexible base group, the difference between the control and surface treatment with plasma was not significant (P = 0.162). Conclusion: In heat-cured denture-base group, the shear bond strength increased significantly with the combination of surface treatment with argon plasma and a chemical bonding agent (PALFIQUE universal). In the flexible denture-base group, the shear bond strength increased significantly with use of a surface treatment with a chemical bonding agent (PALFIQUE universal).

Effect of various irrigation protocols and antioxidant application on bonding performance of two adhesive systems to coronal dentin.

The aim was to evaluate the effect of different irrigation protocols and antioxidants application on the shear bond strength (SBS) of two different adhesive systems to deep coronal dentin at different temperature. One hundred and twenty human premolar teeth were cut longitudinally in two halves, then the prepared specimens were allocated into four main groups according to the irrigation protocols; Distilled water (control), Sodium hypochlorite (NaOCl) + Ethylenediamine Tetra-acetic Acid (EDTA), and NaOCl + Editronate (HEDP), two subgroups according to irrigation solutions temperature; 4°C and 37°C, two divisions according to grape seed extract (GSE) application (with and without), and two subdivisions according to the applied adhesive systems; OptiBond-All-In-One (OPT) and ScotchBond Universal (SBU). Adhesives were applied in self-etch (SE) mode and resin composite material discs were built. Specimens were kept in distilled water for 24-h at 37°C before SBS testing. Four-way ANOVA and Tukey HSD tests were used for data analysis (α=0.05). 4°C irrigants solution temperature showed the least significant SBS values, distilled water group showed significantly higher SBS values compared to NaOCl + EDTA and NaOCl + HEDP groups respectively. GSE application improved dentin bond strength significantly within each adhesive. Increasing the temperature of the irrigation solutions has significantly enhanced the SBS of coronal dentin. Antioxidants application following different irrigation protocols has improved the SBS. Key words:Irrigation protocols, temperature, bond strength, coronal dentin, antioxidant, adhesive systems.

Effect of adding arginine at different concentrations to experimental orthodontic resins: an in vitro study.

The aim of this study was to assess the effect of adding arginine at different concentrations to commercial and experimental orthodontic resins on shear bond strength (SBS), as well as on the antimicrobial activity of arginine against S. mutans. Metal brackets were bonded onto the surface of 120 bovine incisors using Transbond, OrthoCem, and an experimental resin (ER), adding 0, 2.5, 5, and 7 wt.% of arginine. The SBS test was performed in deionized water at 37 ºC for 24 h, at 0.5 mm/min. SBS test results were subjected to two-way ANOVA and Tukey's test (α = 0.05). CFU/mL data (antimicrobial assessment) were assessed by Kruskal-Wallis and Dunn's tests (α = 0.05). No statistical difference between the resins was observed in untreated groups (p > 0.05). The addition of arginine at 2.5% (27.7 MPa) and 5% (29.0 MPa) increased the SBS of Transbond when compared (p < 0.05) to OrthoCem (18.5 and 15.6 MPa, respectively) and ER (16.3 and 18.1 MPa, respectively). Arginine at 7% improved the SBS of Transbond (24.1 MPa) and ER (21.0 MPa), which was statistically higher (p < 0.05) than OrthoCem (12.6 MPa). OrthoCem did not show a statistically significant difference at the three concentrations of arginine (p > 0.05). The addition of arginine to resins reduced the count of S. mutans (p < 0.05). As for ER, all concentrations of arginine significantly decreased CFU/mL (p < 0.05). Among commercial resins, only 7% of arginine significantly reduced CFU/mL. The addition of arginine did not interfere with the bond strength and demonstrated antibacterial activity against S. mutans.

Effect of universal adhesive pretreatments on the bond strength durability of conventional and adhesive resin cements to zirconia ceramic.

This study aimed to evaluate the effect of pretreatment of three different universal adhesives (Single Bond Universal [SBU], All-Bond Universal [ABU], and Prime&Bond universal [PBU]) on the bonding durability of an adhesive (Panavia F 2.0, PF) and a conventional (Duo-Link, DL) resin cements to air-abraded zirconia. Rectangular-shaped zirconia specimens were prepared. The chemical composition and surface energy parameters of the materials were studied by Fourier transform infrared spectroscopy and contact angle measurement, respectively. To evaluate resin bonding to the zirconia, all the bonding specimens were immersed in water for 24 h and the specimens to be aged were additionally thermocycled 10000 times before the shear bond strength (SBS) test. The materials showed different surface energy parameters, including the degree of hydrophilicity/hydrophobicity. While the DL/CON (no pretreatment) showed the lowest SBS and a significant decrease in the value after thermocycling (P < .001), the PF/CON obtained a higher SBS value than the DL/CON (P < .001) and no decrease even after thermocycling (P = .839). When the universal adhesives were used with DL, their SBS values were higher than the CON (P < .05), but the trend was adhesive-specific. In conjunction with PF, the PF/SBU produced the highest SBS followed by the PF/ABU (P = .002), showing no significant decrease after thermocycling (P > .05). The initial SBS of the PF/PBU was similar to the PF/CON (P = .999), but the value decreased after thermocycling (P < .001). The universal adhesive pretreatment did not necessarily show a synergistic effect on the bonding performance of an adhesive resin cement, whereas the pretreatment was beneficial to bond strength and durability of a conventional resin cement.

An In Vitro Exploration of Interaction Mechanisms of Intracoronal Bleaching on the Compressive Strength of Conventional and Calcium Silicate-Based Self-Adhesive Resins and Their Bonding to Composite Resin Restorative Material.

Objectives: The cervical resorption following intracoronal bleaching necessitates the application of impermeable cervical barriers. This study aimed to evaluate the effect of two bleaching agents on the compressive strength (CS) and shear bond strength (SBS) of two self-adhesive resins, TheraCem and Vertise Flow, to composite resin restorative material. Materials and Methods: Two hundred sixteen specimens from TheraCem and Vertise Flow were prepared in special molds and treated in three groups: nonbleached (control); sodium perborate-hydrogen peroxide (SP-HP) (sodium perborate +3% hydrogen peroxide); and HP gel (35% hydrogen peroxide gel). The CS of 72 specimens in the three groups was tested using a universal testing machine. For SBS test, 144 specimens from TheraCem and Vertise Flow in the three groups were bonded to Z250 composite using Single Bond Universal adhesive in self-etch and etch-and-rinse modes. SBS was measured using universal testing machine. Data were analyzed using two-way ANOVA and Tukey tests for CS and three-way ANOVA and Tukey tests for SBS. Results: Vertise Flow showed higher CS than TheraCem (p < 0.001), while none of the bleaching agents deteriorated its CS. HP gel significantly lowered the CS of TheraCem (p = 0.001). Bleaching agents increased the SBS of Vertise Flow while the SBS of TheraCem was not significantly affected. For both resin barriers, SBS was higher in the etch-and-rinse mode (p < 0.05), except in nonbleached Vertise Flow (p = 0.091). Conclusions: HP gel deleteriously affected the CS of only TheraCem during nonvital bleaching. The etch-and-rinse mode was preferred in terms of SBS for resin barriers.

Evaluation of the Bonding Shear Strength between Enamel and Dentin Feldspathic Porcelain and Two Different Monolithic Zirconia with Low and High Translucency.

The utilization of ceramics in the field of dentistry has seen a significant rise owing to their esthetic appeal and excellent functional properties. The use of ceramics in the field of dentistry has witnessed a notable surge, driven by their appealing esthetics and exceptional functional attributes. Zirconia, distinguished by its exceptional mechanical strength, plays a pivotal role in the fabrication of posterior crowns and bridges. Among zirconia variants, monolithic zirconia stands out, where the entire restoration is crafted from zirconia material. In parallel, feldspathic porcelain, chosen for its remarkable resemblance to natural tooth enamel, represents another significant ceramic type. This study aims to evaluate the shear bond strength (SBS) between two types of monolithic zirconia with two types of feldspathic porcelain. Forty-four monolithic zirconia veneered discs with feldspathic porcelain were subjected to SBS testing. The dimensions of the discs were 7 mm in diameter and 5 mm in height (3 mm of zirconia and 2 mm of porcelain). Subsequently, the specimens were subjected to a universal testing machine at a speed of 0.5 mm/min until failure occurred. The type of failure was examined using scanning electron microscopy. One-way analysis of variance (ANOVA), two-way ANOVA, Fisher's test, and multiple Tukey comparisons were used as statistical analyses. The highest SBS was achieved by the high-translucency monolithic zirconia with enamel porcelain group (18.81 ± 3.18 MPa) and the high-translucency monolithic zirconia with dentin porcelain group (17.89 ± 2.75 MPa), followed by the low-translucency monolithic zirconia with dentin porcelain group (15.04 ± 2.24 MPa) and the low-translucency monolithic zirconia with enamel porcelain group (14.33 ± 2.00 MPa), respectively. Additionally, the most common type of failure pattern observed was mixed, followed by adhesive failure. The translucency of the porcelain did not significantly affect SBS, while the type of monolithic zirconia used had a significant impact. Furthermore, there was no discernible relationship between the four groups in terms of the distribution of failure patterns.

Effect of Resin Infiltration and Various Etching Techniques on the Bond Strength of Sound and Demineralized Enamel

Purpose: The objective was to assess the effect of various etching techniques on the shear bond strength(SBS) of resin infiltrated sound/ demineralized enamel. Materials and methods: A total of 180 extracted human upper incisors' enamel surfaces were utilized. Half of these specimens underwent artificial demineralization, which involved exposing to an acidic buffer with a pH of 4.8(14 days). The remaining half of the specimens were kept in their original sound condition. Subsequently, both the sound/ demineralized specimens were divided into 6 groups according to the presence (I)/absence (NI) of resin infiltrant and etching methods (35% phosphoric acid (PA), 9% hydrofluoric acid (HFA), and Er,Cr:YSGG laser(L) (n=15): Following different etching procedures, an etch-and-rinse adhesive system was used, before the application of a nanohybrid composite to the enamel surfaces. Then all specimens were submitted to SBS test (MPa). three-way ANOVA and Bonferroni test were used for statistical analysis(p=0.05). Results: PA showed the highest SBS in the I groups compared with L and HFA groups, both in demineralized and sound enamel (p&amp;lt;0.05). On sound enamel, L showed higher SBS than HFA (p&amp;lt;0.05). On demineralized enamel, L showed similar values with HFA(p&amp;gt;0.05). In the NI groups, L showed similar SBS to HFA on both demineralized and sound enamel(p&amp;gt;0.05). Conclusion:Resin-infiltrated enamel can be etched by 35% phosphoric acid without jeopardize bond strength.

Estimation of some properties of Glass Ionomer Luting Cement reinforced with Zirconium oxide Nanoparticles

Aim of the study: This study was designed to examine the effects of addition of Zirconium oxide nanoparticles (ZrO2NPs) into Glass Ionomer luting cement (GIC) on the film thickness, compressive strength and Shear Bond Strength. Materials and methods: ZrO2NPs at (3% and 5%) concentrations were added to GIC luting cement, while the unmodified GIC cement was used as control. ISO 9917-1:2007 were used for Film thickness test, compressive strength and Shear Bond Strength. Data were analyzed via one-way ANOVA and the Tukey post hoc test, using SPSS version 23. Results: The obtained results revealed a statistically significant difference among the tested groups for Film thickness and compressive strength (P&lt;0.05). Regarding Shear Bond Strength test no significant difference was observed. Conclusion: The incorporation of ZrO2NPs improved compressive strength, increased film thickness concentration-dependently. Yet, didn’t affect shear bond strength.

In Vitro Investigation of Shear Bond Strength of Titanium Alloy Bonded to Monolithic Zirconia Prepared Via Different Surface Roughening Methods Using Different Cements

Objective: To evaluate the shear bond strength (SBS) of yttrium-stabilized tetragonal zirconia polycrystals bonded to titanium alloys via different surface treatment methods using four different cements.&#x0D; Methods: Eighty titanium and monolithic zirconia discs were prepared with computer-aided design/manufacturing (CAD/CAM) technology. All titanium discs and 40 of monolithic zirconia discs were polished by using silicon carbide paper and sandblasted with 50 μm aluminum oxide (Al2O3). Tribochemical silica coating was applied to remaining 40 monolithic zirconia discs. The monolithic zirconia discs were divided into eight groups after surface treatment (n=10). Titanium discs were cemented using conventional glass ionomer cement (GIC), resin-modified GIC, self- adhesive resin cement, and dual-cure resin cement. The SBS test was performed using a universal testing machine. The failure patterns were examined by using a scanning electron microscope (SEM). Data were statistically analyzed with one-way analysis of variance (ANOVA), two-way ANOVA and Tukey’s test (α

Effect of non-thermal plasma treatment and resin cements on the bond strength of zirconia ceramics with different yttria concentrations.

To investigate the effect of different surface treatments and resin cements on the shear bond strength of zirconia ceramics with different yttria concentrations. Zirconia blocks characterized by different yttria concentrations [Vita YZ HT (HT), Vita YZ ST (ST) and Vita YZ XT (XT)] were used to prepare disc-shaped specimens (n=252). Specimens prepared to investigate shear bond strength (SBS), water contact angle and surface roughness (Ra) were divided into four subgroups; control (C), sandblasting (S), sandblasting+nonthermal plasma treatment (SNTP) and nonthermal plasma treatment (NTP). For SBS testing, specimens were further divided into two groups (n=108) according to the luting cement used [Panavia F2.0 (P)and Rely X U200 (R)]. The water contact angles were determined by sessile drop technique and Ra was analyzed with optical profilometer. SBS tests were performed in a universal testing machine at a crosshead speed of 0.5 mm/min. The data sets were statistically analyzed with two and three-way ANOVAs followed by post-hoc comparisons (α=0.05). The water contact angle and Ra data were significantly affected by surface treatments. The mean Ra values of ST and XT were significantly lower than HT for the surface treatment groups of C and NTP. The SBS values were significantly different among the groups subjected to different surface treatments. The mean SBS values of surface treatment groups (S, SNTP and NTP) when cemented with R were significantly higher than the groups of C (p<0.05). For the tested zirconia ceramics with different yttria concentrations, non-thermal plasma activation helps to improve SBS and is a promising tool in practical use.

Shear bond strength between standard or modified zirconia surfaces and two resin cements incorporating or not 10-MDP in their matrix

ObjectiveThis study aimed first to compare the shear bond strength between zirconia samples luted to enamel with a 10-MDP- containing resin cement (Panavia F2.0, Kuraray, Japan) and those luted with a resin cement using a separated 10-MDP monomer-containing bottle (Panavia V5, Kuraray, Japan). The second objective was to evaluate the bond stability after 150 days of aging in water, between enamel and zirconia ceramic surface enhanced with a glass-ceramic coating. Materials and methods80 specimens composed of ceramic cylinders and enamel disks were obtained, within eight experimental groups (n = 10). 60 zirconia cylinders (Katana STML zirconia, Kuraray, Japan) were assigned to 3 groups according to their surface treatment: milled/sintered surface (ZRCT), tribochemical silica-coating (Cojet™ Sand, 3 M ESPE, Seefeld, Germany) (ZRTC), and glass-ceramic coating (IPS e.max Zirpress) (ZRZP). 20 cylinders of lithium disilicate had a milled surface (IPS e.max CAD, Ivoclar-Vivadent, Schaan, Liechtenstein) (ECAD). The cylinders of each group were further divided into two subgroups according to the resin cement used: Panavia F2.0 (-PF) and Panavia V5 (-PV). All specimens were stored in distilled water for 150 days before shear bond strength (SBS) tests. The fracture mode was analyzed, and data were statistically computed (two-way ANOVA, post hoc Tukey test, p < 0.05, SPSS, IBM, v26). ResultsThe ECAD-PF group recorded the highest SBS values (31.75 ± 2.2), and the ZRCT-PF group recorded the lowest values (5.59 ± 1.1). The two-way ANOVA test showed that ceramic surface treatment had a statistically significant effect on SBS (F (3,72) = 38.95, p < 0.001) while the type of ARC did not (F (1,72) = 2.40, p = 0.126). Tukey’s post hoc test revealed no statistical difference between the ZRZP and the ZRTC or ECAD groups. ConclusionWithin the limitations of this study, the PV resin achieved similar shear bond strength results between tribocoated zirconia and enamel compared to the one for glass-ceramic and enamel. Furthermore, a long-term durable bond, similar to the glass-ceramic one, was achieved with the heat pressed ceramic coated specimens. Thus, this new surface treatment could be recommended for anterior cantilever bridges for its fracture resistance and bonding ability.

Development of zirconia-based polymer-infiltrated ceramic network for dental restorative material

Polymer-infiltrated ceramic network (PICN) materials have gained considerable attention as tooth restorative materials owing to their mechanical compatibility with human teeth. However, the mechanical strength of contemporary PICN materials is lower than those of conventional resin composites and ceramics. This study aims to develop novel high-strength PICN for use as a dental restorative material. Zirconia-based PICN (EXP) was fabricated using 3 mol% yttria tetragonal polycrystalline zirconia powder and resin monomers via slip casting, followed by sintering and polymer infiltration. Comprehensive analyses of the microstructure, mechanical properties, and physicochemical properties of EXP were performed using scanning electron microscopy with energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, inorganic content measurements, three-point bending test, Vickers hardness test, two-body wear test, shear bond strength (SBS) test, surface free energy analysis, and water sorption/solubility test. Commercially available computer-aided design/computer-aided manufacturing (CAD/CAM) materials, including resin composite (CERASMART), silicate-based PICN (ENAMIC), and zirconia ceramic (e.max ZirCAD), were used for comparison. The analyses highlight the dual network structure of EXP, which comprised a zirconia skeleton and an infiltrated resin phase. EXP exhibits a flexural strength of 346.0 ± 46.0 MPa, flexural modulus of 44.0 ± 3.7 GPa, and Vickers hardness of 440.1 ± 51.2 VHN. The mechanical properties of EXP are significantly higher than those of CERASMART and ENAMIC but lower than those of ZirCAD. Notably, the EXP hardness closely mimics that of the human enamel. The wear volume, SBS, and water sorption/solubility of EXP are comparable to those of CERASMART and ENAMIC. Therefore, EXP has potential applications as a tooth restorative material.

Improving the Antibacterial Properties of Dental Bonding Materials Loaded with Silver Compounds.

Biofilm accumulation, the appearance of white spot lesions and the development of secondary caries are the main complications in orthodontic patients. A promising approach to fight this situation is the development of adhesive cements with improved antibacterial properties. The aim of the present study was to evaluate the possibility of improving the antibacterial properties of glass ionomer cements by incorporating different types of antimicrobial compounds without altering their physical and mechanical properties. Different concentrations of silver carbonate (SC) and an inorganic glass with encapsulated silver were added to the glass ionomer cement, as well as chitosan, to achieve synergistic antibacterial activity. Variations in the antibacterial capacity were evaluated using the agar diffusion test; the potential alteration of the physical and mechanical properties of the material was analyzed by the shear bond strength test. SEM characterization and colorimetric evaluation were also conducted. Samples of SC up to 1% and inorganic glass with encapsulated silver up to 5% showed significant improvement in their antibacterial ability without compromising shear strength. The highest antimicrobial activity was observed for Lactobacillus acidophilus, with inhibition zones of 3.8 and 3.1 mm for SC and inorganic glass, respectively. The characterization of the samples did not detect any major structural changes between the different samples. The only group that underwent a noticeable color change was the group with SC. The results show that the incorporation of silver carbonate and inorganic glass with encapsulated silver provided the glass ionomer cement with an antibacterial capacity without compromising the bond strength and without modifying the structure of the material.

Shear bond strength of MDP-containing light-cured veneer adhesive system to zirconia with different surface preparations

This study aimed to evaluate the effects of different surface preparation techniques on the surface microstructure, the shear bond strength (SBS) between zirconia and an MDP-containing light-cured veneer adhesive system, and the adhesive failure mode. Sixty-four zirconia specimens were divided into four groups based on surface preparation methods (n = 16), including zirconia sandblasting (ZSB), zirconia vitrification or glaze-on (ZVG), zirconia surface architecture technique (ZSAT), and ZSAT-ZVG combined technique (ZSATVG) groups. Sixteen lithium disilicate specimens prepared by etching with hydrofluoric acid (HF) were used as a positive control group (LDE). Surface roughness measurement and scanning electron microscopy (SEM) evaluation were performed before and after surface preparation. All specimens were then bonded with an MDP-containing light-cured adhesive system, followed by SBS testing and adhesive failure mode analysis. The ZVG and ZSATVG groups showed the greatest differential roughness value and microscopic irregularities, while the ZSAT and LDE groups had the least surface change but the most micromechanical retentive structures for resin infiltration. SBS values were significantly different among groups (p < 0.001) with the highest SBS observed in the ZSAT group, followed by the ZSB group, LDE group, ZSATVG group, and lastly, the ZVG group. There was a statistically significant difference in failure types among the surface preparation groups (p < 0.001). The ZSAT group had the highest frequency of mixed failure, followed by the ZSB group, LDE group, and the ZSATVG and ZVG groups. Establishing direct micromechanical retention within zirconia itself yields a higher bond strength than indirect micromechanical retention within a glass ceramic layer.