Effect of silane primers and unfilled resin bonding agents on repair bond strength of a prosthodontic microfilled composite

This study examined the effect of silane primers and bonding agents on bonding between layers of a light-activated composite material when repaired in the laboratory process. Disk specimens were prepared with the dentin portion of a composite material (Dentacolor DA-30) and abraded with a silicon carbide rotary cutting instrument. The specimens were conditioned with either one of the two silane primers (Porcelain Liner M and Silicer) or one of the two unfilled resin bonding agents (Dentacolor Opaker liquid and New Metacolor Photo Opaque liquid), or one of four combinations of two primers and two bonding agents. An intact surface with a thin air-inhibited unpolymerized layer, and an unprimed surface with only silicone carbide abrasion were also used for references. After placement of the enamel portion of the same brand of composite material (Dentacolor SA-30) on each surface of the dentin material, the specimens were light-exposed, and stored for 24 h in either dry or wet condition. Shear bond strengths were then determined with a mechanical testing device. The results showed that combined use of a silane primer and a bonding agent generally showed the greatest magnitude of bond strength regardless of material variation. The use of an unfilled resin bonding agent after application of a silane primer (Porcelain Liner M) is recommended to ensure adequate repair bonding between layers of the composite material.     

Effect of re-use of a disposable micro-polisher on the surface of a microhybrid resin composite

PURPOSE: To evaluate the surface roughness of Esthet-X resin-based composite with the multi-use of a one-step disposable diamond micro polisher PoGo with profilometer and scanning electron microscope (SEM). METHODS: 35 discs were obtained by condensing Esthet-X in an 8x2 mm plexiglass mold covered with a Mylar strip. The specimens were polymerized 40 seconds on both sides. Five Mylar strips' surfaces were used as a control. Six groups of five discs were formed by reusing the same PoGo disc 1, 2, 3, 4, 5 and 6 times. The surfaces of the 30 discs were ground wet with a 1200 grit silicon carbide paper and then polished 30 seconds with PoGo. The surface roughness was measured with Surtronic 4. One representative sample of each group was selected to visualize the surfaces morphology by SEM. The results were statistically evaluated by one-way ANOVA (P< 0.01). RESULTS: There were no statistical differences with the Mylar-created surfaces and one, two and three times' use of PoGo. Furthermore, reusing PoGo one to four times was not found to affect the surface roughness (P> 0.01). There were no differences with four and five re-uses of PoGo while using the same disc six times exhibited more roughness than single use and Mylar strip (P< 0.01). The SEM and the profilometer revealed similar results.     

Bond strength between fiber posts and composite resin core: influence of temperature on silane coupling agents

This study evaluated the effect of air drying temperature and different silane coupling agents on the bond strength between glass fiber posts and composite resin core. The post surface was cleaned with alcohol and treated with different silane coupling agents, being three prehydrolyzed silanes [Silano (Angelus), Prosil (FGM), RelyX Ceramic Primer (3M ESPE)] and one two-component silane [Silane Coupling Agent (Dentsply)]. Two post-silanization air drying temperatures, 23oC and 60oC, were applied. A cylindrical plastic matrix was placed around the silanized post and filled with composite resin. Each bonded post provided 7 slices for push-out testing. Each slice was loaded to failure under compression at a cross-head speed of 0.5 mm/min. Data were analyzed by two-way ANOVA and Scott-Knott tests (α=0.05). Dunnett's test was used to compare the mean of the control group with that of each experimental group. Scanning electron microscopy (SEM) was used to evaluate the interface of the fractured slices. For the 23oC air drying temperature, the use of RelyX Ceramic Primer resulted in significantly lower bond strength than the other silane coupling agents, while the bond strength with Silane Coupling Agent was the highest of all groups. Only with Silane Coupling Agent, the bond strength for the 23oC air drying temperature was significantly higher than that for 60oC air drying. In conclusion, the use of warm air drying after silane application produced no increase in the bond strength between the fiber-reinforced composite post and the composite core. The two-component silane produced higher bond strength than all prehydrolyzed silanes when it was used with air drying at room temperature.     

Effect of temperature on the silane coupling agents when bonding core resin to quartz fiber posts.

OBJECTIVES: To evaluate the effect of different silane agents and air-drying temperatures on bond strength of translucent quartz fibre posts to composite resin. METHODS: The post surface was etched with 10 vol% hydrogen peroxide for 20 min. A two-liquid coupling agent containing 4-methacryolxyethyl trimellitate anhydride (4-META) and gamma-trimethoxysilyil propyl methacrylate (gamma-MPTS) and two pre-hydrolyzed single component silanes containing 3-methacryloxypropyltrimethoxysilane (3-MPS) and glycid-oxi-propyl-trimetil-oxi-silane (GPS), respectively, were used for treating the fiber posts. Two different post-silanization drying temperatures were applied (21 and 38 degrees C). A dual-cure composite resin (Core Paste XP) was selected to build-up the core around posts, obtaining cylindrical specimens that were serially cut in beams and subsequently loaded in tension (muTBS) at a cross-head speed of 1 mm/min until failure. Bond strength data were statistically analyzed by two-way ANOVA and Student-Newman-Keuls tests (alpha=0.05). RESULTS: Warm air-drying determined significantly higher bond strengths (p<0.001) for glycid-oxi-propyl-trimetil-oxi-silane (11.6 MPa) and 4-methacryolxyethyl trimellitate anhydride/gamma-trimethoxysilyil propyl methacrylate silane (11.7 MPa). These two systems exhibited lower bond strengths (6.9 and 8.8 MPa, respectively) than 3-methacryloxypropyltrimethoxysilane (11.0 MPa) when dried at 21 degrees C. No statistical differences were recorded for 3-methacryloxypropyltrimethoxysilane when drying at 21 or 38 degrees C. SIGNIFICANCE: The composition of the silane coupling agent in terms of acidic content, solvent rate or degree of hydrolysis may influence resin/post bond strength when dried at 21 degrees C. Drying at 38 degrees C most likely facilitates the evaporation of solvents present in the silane agent, resulting in increased bond strength of the composite resin to the fiber post.     

The effect of three silane coupling agents and their blends with a cross-linker silane on bonding a bis-GMA resin to silicatized titanium (a novel silane system)

OBJECTIVES: Three activated organofunctional silane coupling agents alone and blended with a non-functional cross-linker silane were evaluated as adhesion promoters in an experiment where a bis-GMA (bis-phenol-A-diglycidyldimethacrylate) resin was bonded to silicatized titanium. The adhesive performances of the silanes were assessed as shear bond strength values. MATERIALS AND METHODS: 3-Methacryloyloxypropyltrimethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine and [3-(triethoxysilyl)propyl]urea were prepared as 1.0vol.% solutions in 95 vol.% ethanol. They were each also blended with 1.0 vol.% 1,2-bis-(triethoxysilyl)ethane solutions that were activated for 1 or 24 h. Titanium slides were cleaned, silicatized, distributed randomly to study groups and silanized with nine silane solutions. After silanization experimental bis-GMA resin stubs were photo-polymerized and post-polymerized in a light-curing unit. The shear bond strength was measured as 'dry samples' and after thermo-cycling (6000 cycles at 5-55 degrees C). RESULTS: The type of silane affected significantly the shear bond strength (p<0.001) and the use of cross-linker silane (p<0.005) according to the statistical analysis (ANOVA). It showed that the highest shear bond strength for thermo-cycled resin stub samples (n=8/group) was obtained with a blend of 1.0vol.% 3-methacryloyloxypropyltrimethoxysilane+1.0 vol.% 1,2-bis-(triethoxysilyl)ethane blend (10.4+/-3.5 MPa). The lowest results were obtained with 1.0 vol.% [3-(triethoxysilyl)propyl]urea (4.5+/-1.0 MPa), and with 1.0 vol.% N-[3-(trimethoxysilyl)propyl]ethylenediamine (4.5+/-1.4 MPa). CONCLUSIONS: Silanization with a blend of a functional silane and a cross-linker silane (a novel silane system) might improve the hydrolytic stability of a siloxane film between silicatized titanium and a bis-GMA resin.     

不同硅烷偶联剂对瓷和树脂之间黏接强度的影响

目的：比较瓷表面不同酸蚀状态下,4种硅烷偶联剂对瓷和树脂之间黏接强度的影响。方法：将64个瓷试件按照所使用硅烷偶联剂的不同分为4组,每组包括磷酸和氢氟酸处理两个亚组。表面处理完成后将瓷试件与复合树脂黏接,测试剪切强度。结果：氢氟酸与两种双组分偶联剂相配合产生的黏接强度最高（p〈O．05）,两种单组分偶联剂与氢氟酸配合使用的效果同两种双组分偶联剂与磷酸配合使用的效果没有显著差异如〉O．05）。结论：不同种类偶联剂对瓷和树脂之间的黏接强度有明显影响,选用合适的双组分硅烷偶联剂与磷酸处理相配合,足以产生满足临床要求的黏接强度。     

Microleakage of a microhybrid composite resin using three different adhesive placement techniques

PURPOSE: To evaluate the efficacy of two adhesive systems in reducing microleakage when applied with three different adhesive placement techniques. MATERIALS AND METHODS: Sixty freshly extracted caries-free human premolars and molars were used. MO/DO Class II standardized preparations were performed with the gingival margin placed 1 mm above the CEJ. Teeth were randomly divided into 2 groups (group I: Prime& Bond NT, Dentsply/Caulk; group II: Single Bond, 3M Espe). Each group was divided into 3 subgroups: (A) application of 2 coats and one cure: IA-IIA; (B) 2 coats and 2 cures of each adhesive system: IB-IIB; and (C) one coat of each adhesive along with the manufacturers' B1 flowable resin (0.5-mm thick layer) cured together at once: IC-IIC. Each coat was cured for 20 s at 800 mW/cm2 using a quartz-tungsten halogen light (Elipar Trilight, 3M ESPE). Teeth were then restored using 2-mm increments of an A2 microhybrid composite (Esthet-X, Dentsply/Caulk). All teeth were stored in distilled water at 37 degrees C for 24 h, thermocycled (500x, 5 degrees to 55 degrees C, 30 s dwell) and then placed in a 0.5% methylene blue dye solution for 24 h at 37 degrees C. Samples were sectioned longitudinally and evaluated for microleakage at the gingival margin under a stereomicroscope at 20x magnification. Dye penetration was scored using an ordinal scoring system, where 0: no penetration; 1: enamel penetration; 2: gingival dentin penetration; 3: axial dentin penetration. Kruskal-Wallis and Mann-Whitney tests were used. RESULTS: A Mann-Whitney U-Test revealed no statistically significant difference between subgroups. Although not statistically significant, P&B NT (two coats and one cure) revealed the lowest microleakage scores. CONCLUSION: In the experimental model adopted for this study, microleakage was not affected either by the adhesive or its placement technique.     

Graphene oxide‐based experimental silane primers enhance shear bond strength between resin composite and zirconia

Despite various mechanical and chemical surface‐pretreatment methods, long‐term bonding of resin composite to dental zirconia (ZrO₂) remains a major concern. In this study, graphene oxide (GO) sheets were infused into two commercially available primers and the enclosed mould shear bond strength (EM‐SBS) of resin composite to ZrO₂ was evaluated. Twelve fully sintered ZrO₂ blanks were pretreated and randomly allocated to four groups according to the primers used: RelyX (RX); GO blended RelyX (RXGO); Monobond‐S (MB); and GO blended Monobond‐S (MBGO). The resin composite stubs were bonded onto the pretreated ZrO₂ surfaces and analysed at baseline and after storage in distilled water for 2 and 4 months. The experimental primers blended with GO sheets influenced the surface morphology, visualized as increased surface roughness, and slightly increased the water contact angle measurements. Moreover, the infusion of primers with GO increased the mass fraction (wt%) of carbon and oxygen. The highest EM‐SBS values were found for RXGO, with mean (SD) EM‐SBS values of 26.4 (3.7) MPa and 21.5 (5.1) MPa after 2 and 4 months of storage, respectively. Infusion of silane primers with nanometre‐ to micrometre‐size GO sheets enhanced the SBS between resin composite and ZrO₂.     

复合树脂中硅烷偶联剂γ-MPs水解与缩合机制的研究

目的：研究复合树脂中最常用的硅烷偶联剂γ－MPS水解与缩合的机制。方法：应用傅立味变换红外光谱（FT－IR）法对γ－MPS及其水解液在不同状态时的特征吸收谱带进行分析。结果：（1）γ－MPS水解后其分子结构中Si-O-CH3基团消失，水解产物中出现具有反应活性的Si-OH基团，C＝O基的伸缩振动向低频率发生位移。（2）γ－MPS水解液旋转h时，溶液中已有线性硅氧烷醇齐聚物存在。（3）随γ－MPS水解液旋转时间延长，Si-OH吸收强度减弱，而Si-O-Si吸收强度增强。同时C＝O基的伸缩振动向高频率发生位移，表明γ－MPS水解液在不断进行缩合。结论：本研究从分子水平上揭示了硅烷偶联剂γ－MPS水解液随旋转时间变化，其分子间发生缩合的规律，为有效合理地使用γ－MPS偶联剂提供理论依据。     

Effect of silane and MDP-based primers on physico-chemical properties of zirconia and its bond strength to resin cement

ObjectiveTo evaluate the effect of surface treatments on yttria-tetragonal zirconia polycrystal (Y-TZP) characteristics and on resin-mediated zirconia bond.MethodsY-TZP slabs were grit blasted with 45 μm alumina or with 30 μm silica-coated alumina particles. The chemical treatments were: no-chemical treatment (NC), silane-containing primer (SP), MDP (10-Methacryloyloxydecyl dihydrogen phosphate) and silane-containing primer (MPS), MDP-containing primer (MP) and MDP and silane-containing adhesive (MPA). Contact angle as a function of surface roughness (θ_m) and surface roughness parameter (Sdr) were measured using Fringe Projection Phase Shifting (FPPS). Surface free energy (γ_s^TOT) was calculated with a goniometer. Chemical interaction between primers/adhesive and zirconia was analyzed using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Resin cement microshear bond strength (μSBS) was analyzed at either 24-h or 8-months water storage (37 °C). θ_m values, Sdr values, γ_s^TOT and μSBS values were analyzed using Analysis of variance (ANOVA) and post hoc Tukey test (α = 0.05).ResultsChemical treatment had an effect (p < 0.001) on all surface parameters analyzed: θ_m, γ_s^TOT and Sdr. MP-treated group showed higher incidence of P–O–Zr bonds than the other groups, indicating more chemical linkages. Grit blasting (p < 0.001) and the interaction chemical treatment*storage (p < 0.001) did not affect μSBS; all silane-containing primers showed significant drop in μSBS after aging.SignificanceMDP and/or silane-based solutions affect the physicochemical properties of blasted-zirconia. An MDP-based primer is fundamental to achieve a stable resin-zirconia bonding, but the chemical reactivity of MDP is impaired when this molecule is present in a multicomponent system.     

Effect of temperature on the flow properties of resin composite

This study evaluated the effect of temperature on the flow characteristics of three different resin composites: a packable, a microhybrid, and a flowable. The film thickness of the three composites was measured at 21 degrees C, 41 degrees C, 61 degrees C, and 83 degrees C (+/- 1.0 degrees C). Five tests were performed for each resin composite at each of the four test temperatures for a total of 60 tests. The resin composite film thickness decreased as the filler percentage decreased and the temperature increased. The film thickness decrease was a logarithmic fit with a high correlation coefficient. All of the resin composites exhibited increased flow at elevated temperature. The flow property of the packable material at 41-61 degrees C was similar to that of the microhybrid at room temperature.     

Effect of temperature on unpolymerized composite resin film thickness

STATEMENT OF PROBLEM: Room temperature (RT) composite resins are viscous, and this condition may affect the ability of the material to flow and adapt to preparation walls. PURPOSE: The purpose of this study was to compare the film thickness of a variety of commercial composite resins heated prior to light polymerization. The film thickness of these heated materials was also compared to those of flowable products at RT. MATERIAL AND METHODS: Five flowable and 7 conventional composite resins were used: 2 microfills, a nanofill hybrid, 2 submicron hybrids, a trimodal hybrid, and a packable. Composite resin (0.05 mL) was pressed between 2 Mylar-covered glass plates (15 kg) for 180 seconds, light polymerized, and the thickness measured using a micrometer. When comparing conventional composite resin heated to 54 degrees C or 60 degrees C, the RT value was control, while the RT flowable values were control when compared to heated composite resin. (n=5/group). Data were analyzed using 1- and 2-way analysis of variance and the Tukey-Kramer post hoc test (alpha=.05). Correlation of filler content to flow potential was evaluated. Scanning electron microscopic analysis of polymerized specimens was characterized by filler size and shape. RESULTS: Room temperature conventional composite resin values varied in film thickness. Not all preheated products reduced in thickness. Thickness of the nanofill did not reduce, and one of the submicron hybrids reduced the greatest. No correlation existed between composite resin classification, filler content or shape, and film thickness. No difference in thickness existed between composite resins preheated to 54 degrees C and 60 degrees C. Room temperature and preheated conventional composite resin provided film thickness greater than that of flowable materials. CONCLUSIONS: Preheating conventional composite resin yields lower film thickness for some products, but flow cannot be attributed to composite resin classification, filler content, or shape. Preheated composite resin thickness was greater than that of all flowables.     

Effect of preparation mode on Class II resin composite repair

Complete removal of failed posterior resin composite fillings is time-expensive and involves the risk of removing sound tooth substance. In any case of failure within the composite material, intra-oral repair would be favourable. This in vitro study was conducted to examine the effect of different preparation and bonding modes on integrity of repaired restorations. Forty-eight direct Class II resin composite restorations (Syntac Classic/Tetric Ceram) were placed in extracted human third molars. The specimens were stored for 365 days and then replaced partially by removing the central part of the proximal box with all margins located in composite. The partial repairs were placed with the same materials after pre-treatment with a silicon carbide bur and Syntac Classic (n = 8). Preparation modes have been (i) box-only parallel, (ii) box-only with undercuts, (iii) box with undercuts and additional occlusal retention. The repairs were performed either with (i) Tetric Ceram or with (ii) Tetric Flow as thin lining covered with Tetric Ceram. Before and after thermomechanical loading (100 000 cycles of 50 N and 2500 cycles between +5 and +55 degrees C in an artificial mouth), marginal quality between aged and freshly applied composite was evaluated by SEM at x200 magnification and microleakage was observed by light microscopy at x50 magnification. Box-only preparations exhibited a better fatigue resistance than preparations with additional occlusal retention. This observation was independent from the presence of undercuts (P < 0.05). An intermediary layer of flowable resin composite tended to result in better marginal quality, however, not being statistically significant.     

硅烷偶联剂的用量对钛酸钾晶须增强复合树脂的抗弯强度的影响

目的：研究硅烷偶联剂用量对钛酸钾晶须增强复合树脂抗弯强度的影响。方法：分别采用0．5％、1％、2％、3％、4%（质量比）的硅烷偶联剂KH-570对钛酸钾晶须进行表面处理,再以60％（质量比）的填充量把处理过的5组晶须混合到树脂基质中,并制成标准试件,进行三点弯曲测试及断面的电镜扫描。结果：5组试件的抗弯强度分别是（98．55±12．01）Mpa、（100．60±17．39）MPa、（107．80±5．25）MPa、（134．18±12．90）MPa、（102．15±10．36）MPa,对其进行均数间的两两比较（Tukey检验）可知,3％硅烷偶联剂处理组的抗弯强度在α=0．01的水平上与其它组结果具有显著性差异,其余4组间差异无统计学意义。3．0％硅烷偶联剂处理组断裂面的扫描电镜照片显示晶须与树脂间的结合良好。结论：硅烷偶联剂KH-570能够增强钛酸钾晶须和树脂间的界面结合强度,但其太多太少均会造成界面结合强度都会下降,本试验KH-570的用量3％时,增强效果最好。     

Effects of silane coupling agent amount on mechanical properties and hydrolytic durability of composite resin after hot water storage

The purpose of this study was to evaluate the effects of the silane coupling agent amount on the flexural properties and hydrolytic durability on an experimental composite resin for understanding the optimum amount of silanation. A spherical filler was silanated with 7 different amounts of gamma-MPTS, 0, 0.17, 0.34, 0.66, 1.36, 2.72 and 5.45 mass%. Photopolymerized experimental composite resins were made from a 70/30 mass% of UDMA/TEGDMA and a 65 mass% of different silanated amounts of filler. Bar-shaped specimens were prepared for a 3-point bending test in 37 degrees C water after 1-day water storage at 37 degrees C and after an additional 1, 7, and 28 days hot water storage in Soxhlet's extractor. The flexural strength and flexural modulus of unsilanated filler dramatically decreased after 28 days hot water storage while those of silanated filler showed a slight change. These results suggested that the silanated amount on the silica filler is not sensitive for flexural properties and hydrolytic stability of composite resin.     

A clinical evaluation of packable and microhybrid resin composite restorations: one-year report.

OBJECTIVE: The objective of this study was to evaluate the clinical performance of two packable and one microhybrid resin composites placed in occlusal cavities of posterior permanent teeth after 1 year. METHOD AND MATERIALS: Sixty occlusal restorations were placed in 18 male or female patients aged 21 to 44 years. The restorations were divided into three groups according to the restorative material: G1 (Surefil + Prime&Bond NT); G2 (Filtek P60 + Singlebond), and G3 (Suprafill + Suprafill). They were placed by two previously calibrated operators. The restorations were directly evaluated for color matching, marginal discoloration, secondary caries, wear, marginal adaptation, and postoperative sensitivity. RESULTS: Of the total restorations, 66.7% were scored A (ideal) for color matching; 98.2% for marginal discoloration; 100% for secondary caries; 92.6% for wear; and 92.6% for marginal adaptation. Postoperative sensitivity was reported in 5% of the restorations. Fisher's exact, McNamara's, and chi-square tests did not indicate statistical difference between the groups, related to the evaluated criteria. CONCLUSIONS: The packable (Filtek P60 and Surefil) and the microhybrid (Suprafill) resin composites exhibited excellent clinical performance after 1 year and may be considered possible materials for the restoration of posterior teeth.     

Effect of silane activation on shear bond strength of fiber-reinforced composite post to resin cement

PURPOSE

Among the surface treatment methods suggested to enhance the adhesion of resin cement to fiber-reinforced composite posts, conflicting results have been obtained with silanization. In this study, the effects of silanization, heat activation after silanization, on the bond strength between fiber-reinforced composite post and resin cement were determined.

MATERIALS AND METHODS

Six groups (n=7) were established to evaluate two types of fiber post (FRC Postec Plus, D.T. Light Post) and three surface treatments (no treatment; air drying; drying at 38℃). Every specimen were bonded with dual-curing resin cement (Variolink N) and stored in distilled water for 24 hours at 37℃. Shear-bond strength (MPa) between the fiber post and the resin cement were measured using universal testing device. The data were analyzed with 1-way ANOVA and by multiple comparisons according to Tukey''s HSD (α=0.05). The effect of surface treatment, fiber post type, and the interactions between these two factors were analyzed using 2-way ANOVA and independent sample T-tests.

RESULTS

Silanization of the FRC Postec Plus significantly increased bond strength compared with the respective non-treated control, whereas no effect was determined for the D.T. Light Post. Heat drying the silane coupling agent on to the fiber-reinforced post did not significantly improve bond strength compared to air-syringe drying.

CONCLUSION

The bond strength between the fiber-reinforced post and the resin cement was significantly increased with silanization in regards to the FRC Postec Plus post. Bond strength was not significantly improved by heat activation of the silane coupling agent.     

Effectiveness of two-liquid silane primers on bonding sintered feldspathic porcelain with a dual-cured composite luting agent

The purpose of the current study was to evaluate the effect of two-component ceramic primers on the bond strength of a composite material joined to a sintered porcelain material. Two sizes of porcelain discs (VMK 68; 10 and 8 mm in diameter by 2.5 mm thick) were ground (No. 1000 SiC), and surface-conditioned using one of the following systems: (i) unprimed, (ii) Liquid A of the Porcelain Liner M material (PLM-A), (iii) Liquid B of Porcelain Liner M (PLM-B), (iv) Liquids A and B of Porcelain Liner M (PLM-AB), (v) Liquid A of the Tokuso Ceramics Primer material (TCP-A), (vi) Liquid B of Tokuso Ceramics Primer (TCP-B) and (vii) Liquids A and B of Tokuso Ceramics Primer (TCP-AB). All specimens were bonded with the Bistite II dual-cured composite luting agent, and shear bond strengths were determined both after 24 h immersion in water and after subsequent thermocycling (4-60 degrees C, 1 min each, 20,000 cycles). Of the seven groups assessed, two groups (PLM-AB and TCP-AB) showed the greatest bond strength both before (30.7 MPa for PLM-AB and 29.7 MPa for TCP-AB) and after (19.7 MPa for PLM-AB and 22.4 MPa for TCP-AB) thermocycling (P < 0.05). No significant differences were found between the PLM-AB and TCP-AB groups regardless of the application of thermocycling (P > 0.05). It can be concluded that both of the acid-catalysed two-liquid ceramic primers showed superior bonding to the unhydrolysed single-liquid silane agents (PLM-B and TCP-A) when the feldspathic porcelain was bonded with the Bistite II luting composite.