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OBJECTIVE: This study examined the effect of the number of phosphate-containing primer applications on the shear bond strength (SBS) of zirconia to resin cement. MATERIALS AND METHODS: 315 square specimens (10 × 10 × 4 mm3) were manufactured from Cercon ht presintered zirconia blocks. Alumina particles were used to sandblast zirconia specimens. These specimens were randomly divided into six primer-based groups: No primer application (NP), CLEARFIL CERAMIC PRIMER (C), PANAVIA V5 Tooth Primer (T), M&C PRIMER (MC), Monobond N (MN), and Z-PRIME plus (Z), and then separated into application number (1-4) groups (excluding NP). Each specimen was bonded with resin cement. The SBS was measured using a universal testing machine. The debonded surface was examined with a stereomicroscope. STATISTICAL ANALYSIS: The SBSs were analyzed using two-way analysis of variance. RESULTS: Applying the primer twice exhibited the highest SBSs in each group, with significant differences in the T, MN, and Z groups. However, the SBS in the MC group was significantly lower on the second application. One-hundred percent adhesive failure was observed in all groups. CONCLUSION: Within the limitations of this study, prior to cementation, the sandblasted zirconia surface should be applied twice with a phosphate-containing primer other than MC to maximize the SBS at the zirconia-resin cement interface.

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OBJECTIVE: This study investigates the effect of different chemical surface treatment protocols with different functional monomers of universal adhesives on the shear bond strength between resin-matrix ceramic and resin composite. MATERIALS AND METHODS: Eighty resin-matrix ceramics (Shofu block HC) were built and designed into eight groups of ten specimens and surface treated with HC primer (HC) and/or three universal adhesives (single bond universal [SBU], Scotchbond universal plus [SBP], and Tetric N-bond universal [TNU]) assigning follows; group 1, nonsurface treated; group 2, HC; group 3, SBU; group 4, HC + SBU; group 5, SBP; group 6, HC + SBP; group 7, TNU; group 8, HC + TNU. A template was put on the specimen center, and then pushed packable resin composite. Mechanical testing machinery was used to examine the samples' shear bond strength (SBS) values. To examine failure patterns, the debonded specimen surfaces were examined by a stereomicroscope. STATISTICAL ANALYSIS: The one-way analysis of variance method was used to evaluate the data, and the Tukey's test was used to determine the significant level (p < 0.05). RESULTS: The highest SBS was obtained in group 6 (39.25 ± 1.65 MPa). Group 1 (4.15 ± 0.54 MPa) had the lowest SBS. Group 6 exhibited the highest percentage of cohesive failure patterns (70%). High SBS values were frequently correlated with the surface treatment groups and the cohesive failure patterns. CONCLUSION: The application of HC primer prior to the universal adhesive is an alternative protocol for enhancing the repair bond strength between resin-matrix ceramic and resin composite interfaces. Moreover, the application of HC primer prior to the SBP is the best strategy for resin-matrix ceramic and resin composite repairs.

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To assess color and translucency change (∆E00 and ∆TP) of 3D-printed (Varseosmile crown plus, VS) and milled resin-ceramic hybrid material (Cerasmart, CS) compared to enamel (E) when immersed in distilled water (DW) and coffee (C). Sixty VS, CS, and E specimens were immersed in DW and C for 30 days. Statistics analysis using t-test and one-way ANOVA at p≤0.05. ∆E00 of VS, CS, and E significantly increased when immersed in coffee (p<0.001, p<0.001 and p=0.01, respectively). E has more ∆E00 than VS and CS (p<0.001). The translucency of VS and CS was reduced after water and coffee immersion. The translucency of E was increased after immersion in water and coffee. ∆TP of VS, CS, and E were not different between immersion in water and coffee at p=0.08, p=0.43 and p=0.72, respectively. Therefore, DW and C have distinct effects on the ∆E00 and ∆TP among VS, CS and E.

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Introduction: Nanoparticulate Ca(OH)2 had greater antibacterial effect than conventional Ca(OH)2. Conversely, a study reported that nanoparticulate Ca(OH)2 had toxicity against murine fibroblast. However, the study of nanoparticulate Ca(OH)2, involving human dental pulp cells (DPCs) and apical papilla cells (APCs) is lacking. The aim of this study is to compare the effects of conventional Ca(OH)2 and nanoparticulate Ca(OH)2 on the viability of DPCs and APCs. Methods: Primary human DPCs/APCs from the 3rd to 5th passage were divided into control and experimental groups. In the control group, cells were cultured in complete media. In the experimental group, cells were cultured in complete media containing 10, 100, or 1000 µg/mL of either conventional Ca(OH)2 or nanoparticulate Ca(OH)2 for 1, 3, 5, and 7 days. After the treatment period, the cells were tested for viability using MTT assay. Results: DPCs treated with conventional Ca(OH)2 in all concentrations at day 5 revealed significantly higher proliferation compared to nanoparticulate Ca(OH)2 treated groups. In additions, DPCs treated with 1000 µg/ml nanoparticulate Ca(OH)2 at day7 were significantly lower proliferation compared to DPCs treated with conventional Ca(OH)2. In contrast, APCs treated with 1000 µg/ml nanoparticulated Ca(OH)2 were significantly higher proliferation than APCs treated with 1000 µg/ml conventional Ca(OH)2 at day7. Conclusions: Nanoparticulate Ca(OH)2 increased the viability of APCs and can be an alternative choice of intracanal medication for regenerative endodontic procedures. However, Nanoparticulate Ca(OH)2 exerted some effects on DPCs. The use of nanoparticulate Ca(OH)2 has no advantages over the conventional Ca(OH)2 for vital pulp therapy.

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This investigation evaluated the effects of aprotic solvents, i.e., tetrahydrofuran, pyridine, and morpholine, compared with hydrogen peroxide, on the surfaces of fiber-reinforced composite posts with a composite core based on the microtensile bond strength. In total, 150 FRC Postec Plus posts and 150 D.T. Light-Posts were randomly divided into three groups (non-thermocycling, 5000-cycle, and 10,000-cycle thermocycling groups). Each group was divided into five subgroups according to the post-surface treatment: C, non-treatment group; H2O2, immersed in 35% hydrogen peroxide; THF, immersed in tetrahydrofuran; PY, immersed in pyridine; and MP, immersed in morpholine. The treated specimens were placed in the bottom of a plastic cap and filled with a composite core material in preparation for the microtensile bond test. The data were evaluated using one-way ANOVA and Tukey's test (p < 0.05) as well as an independent t-test (p < 0.05). For the surface roughness, white light interferometry was used for measurement, and the mean surface roughness was analyzed via one-way ANOVA and Tukey's test (p < 0.05). The results showed that, under non-thermocycling conditions, the PY subgroup with D.T. Light-Post had the highest microtensile bond strength, followed by THF, MP, H2O2, and the control groups. For FRC Postec Plus, the PY group had the highest microtensile bond strength, followed by MP, THF, H2O2, and the control groups. Although the thermocycling conditions decreased the microtensile bond strength in all groups, the PY subgroup still had the highest value. An independent t-test revealed that even under all non-thermocycling and 5000- and 10,000-cycle thermocycling conditions, D.T. Light-Post in the PY subgroup displayed significantly higher microtensile bond strengths than FRC Postec Plus in the PY subgroup. While the surface roughness of the fiber-reinforced composite posts showed that the posts treated with pyridine possessed the highest surface roughness for each material type, In conclusion, as an aprotic solvent, pyridine generates the highest microtensile bond strength between the interfaces of composite cores and fiber-reinforced composite posts.

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Using anti-COVID-19 mouthwashes has become necessary to reduce acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmissions. Resin-matrix ceramic (RMCs) materials that are exposed to mouthwashes may affect the bonding of repaired materials. This research was performed to assess the effects of anti-COVID-19 mouthwashes on the shear bond strengths (SBS) of RMCs repaired with resin composites. A total of 189 rectangular specimens of two different RMCs (Vita Enamic (VE) and Shofu Block HC (ShB)) were thermocycled and randomly divided into nine subgroups according to different mouthwashes (distilled water (DW), 0.2% povidone-iodine (PVP-I), and 1.5% hydrogen peroxide (HP)) and surface treatment protocols (no surface treatment, hydrofluoric acid etching (HF), and sandblasting (SB)). A repair protocol for RMCs was performed (using universal adhesives and resin composites), and the specimens were assessed using an SBS test. The failure mode was examined using a stereomicroscope. The SBS data were evaluated using a three-way ANOVA and a Tukey post hoc test. The SBS were significantly affected by the RMCs, mouthwashes, and surface treatment protocols. Both surface treatment protocols (HF and SB) for both RMCs, whether immersed in anti-COVID-19 mouthwash or not, improved the SBS. For the VE immersed in HP and PVP-I, the HF surface treatment had the highest SBS. For the ShB immersed in HP and PVP-I, the SB surface treatment had the highest SBS.

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OBJECTIVE: The study's objective was to evaluate skeletal changes in 38 skeletal class III patients following mandibular setback surgery using NM-Low Z plasty. MATERIALS AND METHODS: Thirty-eight skeletal class III patients (ANB angle lower than 0) who underwent the NM-Low Z plasty technique for surgical mandibular setback procedure at Thammasat University Hospital between January 2017 and March 2020 were included in the study: 29 patients had two jaw surgeries, and 9 patients had one jaw surgery. An additional 14 patients had genioplasty. Three lateral cephalograms were traced and digitized with Dolphin Imaging software: T0, T1, and T2. The distance between the B-point and the SN7 perpendicular line defined immediate changes after surgery (T1-T0) and stability after surgery (T2-T1). The reliability test included 6 cephalograms retraced after 2-week interval. At point B, the principal result was horizontal movement forward. STATISTICAL ANALYSIS: The analysis used paired t-tests. RESULTS: The mean mandibular setback was 9.78 mm, and the mean skeletal relapse was 2.61 mm, or 26.69%. Statistical analysis showed postoperative differences (p < 0.05). Vertical measurement in B-SN7 reduced immediately and postoperatively. CONCLUSION: Postoperatively, the mandible relapsed significantly forward and upward. Rotational relapse is a concern with NM-Low Z plasty in hypo-/: normodivergent patients.

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OBJECTIVE: This study examined the chemical surface modification methods of resin composite repaired with resin-modified glass-ionomer cement (RMGIC). MATERIALS AND METHODS: Ninety aged resin composite rods were produced and sorted into 9 groups of 10 specimens and surface modified with silane agent and/or bonding agent as follows: group 1, no surface modified; group 2, etch + single bond 2 (SB2); group 3, SB2; group 4, etch + RelyX ceramic primer (RXP) + SB2; group 5, RXP + SB2; group 6, etch + single bond universal (SU); group 7, SU; group 8, etch + RXP + SU; and group 9, RXP + SU. A clear silicone mold was placed on the top of specimen center, and then filled with RMGIC. The specimens' shear bond strengths (SBSs) were examined in mechanical testing equipment. To determine failure types, the fractured specimen surfaces were inspected using a stereomicroscope. STATISTICAL ANALYSIS: The data collected were analyzed using one-way analysis of variance, and significance level was operated using Tukey's test (p < 0.05). RESULTS: Group 8 had the greatest SBS, but it was statistically indistinguishable from groups 4, 5, and 9. The most frequent fracture mode was adhesive failure. High SBS was commonly associated with mixed failure. CONCLUSION: The use of bonding agents enhances the resin composite's wettability and allows it to bond to RMGIC. Moreover, the use of the silane coupling agent before applying bonding agent showed significantly higher bonding ability of resin composite and RMGIC interface.

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OBJECTIVE: This study determined the potency of resin infiltrations and resin sealant in impeding microleakage on artificial white-spot lesions (AWL) by methylene blue penetration. MATERIALS AND METHODS: Eighty AWL specimens were randomly separated into two groups for water storage for 24 hours (groups 1-4) and 20,000 cycles of thermocycling (TC) (groups 5-8). Each group was then separated into four subgroups (n = 10) based on the AWL surface treatments: (1) no Tx, (2) treated with resin infiltration (ICON, DMG, Hamburg, Germany), (3) treated with resin infiltration (Surface pre-reacted glass-ionomer (S-PRG) barrier coat, SHOFU, Kyoto, Japan), (4) treated with resin sealant (Clinpro sealant, 3M ESPE, Minnesota, United States). Nail varnish was covered to all samples, with the exception of a 4 × 4 mm2 patch on the buccal measurement region, which was subsequently submerged in a 2% methylene blue solution and cut into buccolingual sections. Stereomicroscope measurements were used to calculate methylene blue penetration scores. STATISTICAL ANALYSIS: The Kruskal-Wallis test and the Bonferroni post-hoc correction were performed to evaluate the data. RESULTS: Application of resin infiltrants and resin sealant reduced microleakage in AWL by methylene penetration both before and after thermal cycling. In addition, group 6 (ICON + TC) and group 7 (S-PRG + TC) had a significantly different value from group 8 (sealant + TC). CONCLUSION: Both the resin infiltration approach and the resin sealant seem to help seal AWL and might perhaps offer long-term defense against microleakage in AWL caused by methylene blue penetration. The greatest sealing and defense for microleakage in AWL were demonstrated by the resin infiltrations.

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The aim of this study was to specifically explore the effects of morpholine on chemical surface treatments of aged resin composites contaminated with saliva to new resin composite repair strength. One hundred and thirty five resin composite specimens were fabricated and thermocycled to replicate an aged resin composite. These aged resin composites were randomly separated into nine groups (n = 15) depending on the various surface contaminants and surface treatment techniques. These groups were as follows: group 1­no surface treatment; group 2­no saliva + adhesive agent; group 3­no saliva + morpholine + adhesive agent; group 4­no saliva + morpholine; group 5­saliva; group 6­saliva + adhesive agent; group 7­saliva + morpholine + adhesive agent; group 8­saliva + morpholine; and group 9­saliva + phosphoric acid + adhesive agent. A mold was covered on the top of the specimen center and then filled with resin composite. The shear bond strengths and failure modes were examined. The collected data was analyzed using one-way ANOVA, and the significance level was determined using Tukey's test. Group 5 (3.31 ± 0.95 MPa) and group 6 (4.05 ± 0.93 MPa) showed the lowest bond strength statistically, while group 3 (23.66 ± 1.35 MPa) and group 7 (22.88 ± 1.96 MPa) showed the most significantly high bond strength. The bond strength in group 2 (16.41 ± 1.22 MPa) was significantly different from that in group 1 (9.83 ± 1.13 MPa), group 4 (10.71 ± 0.81 MPa), and group 8 (10.36 ± 1.53 MPa), while group 9's (17.31 ± 1.48 MPa) SBS was not significantly different. In conclusion, the application of morpholine on aged resin composite with or without contamination with saliva prior to the application of the adhesive agent increased the bond strength of aged resin composite repaired with new resin composite (p < 0.05).

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Occasional chipping can still occur with zirconia material despite its high strength. Emergency repairs can be accomplished using zirconia primer, adhesive agent, and resin composite when the fracture of zirconia exposes the zirconia framework. Phosphate-containing primers play an important role in zirconia surface treatment. The objective of this investigation was to evaluate the effect of multiple applications of phosphate-containing primer on shear bond strength between zirconia and resin composite. In this case, 78 zirconia discs were sandblasted by alumina particles; the zirconia was then randomized into six groups for single application and multiple applications of phosphate-containing primer according follows; group 1: no application, group 2: one application, group 3: two applications, group 4: three applications, group 5: four applications, and group 6: five applications. Adhesive was applied on the zirconia surface and the resin composite was bonded. Shear bond strength was assessed using a universal testing machine. The de-bonded surface was examined using a stereomicroscope. The shear bond strengths were statistically analyzed with one-way ANOVA and Bonferroni. Group 1 had the lowest shear bond strength with a significant difference compared to groups 2-6, whereas group 4 had the highest shear bond strength, with no significant difference compared to groups 5-6. The failure mode revealed 100% adhesive failure in all groups. In conclusion, to maximize shear bond strength at zirconia and resin composite interfaces, sandblasted zirconia surfaces should be treated with three applications of phosphate-containing primer prior to the adhesive agent.

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Aim: This study examined the influence of various functional monomers in two self-adhesive resin cements (SACs) on prosthetic materials. Materials and Methods: Base metal alloy, lithium disilicate glass-ceramic, and zirconia were used as bonding materials. Silicon carbide paper was used to polish the specimens. Two self-adhesive resin cements (Panavia SA luting multi, PAM, and Maxcem elite chroma, MAC) were used. Ten specimens for each material were produced and resin cements were bonded to each material. The specimens were stored in 37°C distilled water in an incubator for 24 hours. A universal testing machine was used to measure the shear bond strength. The data were statistically examined using one-way ANOVA and Tukey's test. Results: In all prosthetic materials, PAM had the highest bond strength. In lithium disilicate glass-ceramic, the lowest bond strength was found with MAC. Conclusion: The self-adhesive resin cement (PAM) containing 10-MDP monomer and long carbon-chain silane was performed the greatest outcome in the shear bond strength on the prosthetic materials and self-adhesive resin cement interface.

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OBJECTIVES: This study evaluated the surface microhardness of composite, affected by surface coating with different dental adhesive systems. MATERIALS AND METHODS: A total of 100 composite discs were divided into five groups. Group 1 was uncoated (control group C), and groups 2 to 5 were coated with different adhesive systems (OptiBond FL: FL, OptiBond SOLO Plus: SOLO, OptiBond XTR: XTR, and OptiBond All in one: AIO, respectively). The Vickers microhardness (VHN) was measured without and with 500 thermocycles. STATISTICAL ANALYSIS: The data were analyzed using two-way ANOVA and Tukey's posthoc test at the 95% confidence level. RESULTS: At 24 hours, the VHN of C (59.96 ± 3.68) and FL (59.83 ± 4.54) were significantly higher than SOLO (51.73 ± 4.63) and AIO (51.45 ± 4.11). The VHN of XTR (54.96 ± 3.68) was not significant compared with that of C and all other groups. After thermocycling, VHN were significantly decreased in all groups. However, there were no significant differences among all groups. CONCLUSIONS: At 24 hours, composite coated with different adhesive systems have different effects to VHN. Thermocycling all adhesive resin systems coated on composite surface significantly decreased the VHN.

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OBJECTIVE: This study examined the effectiveness of different functional monomers in universal adhesives on zirconia/resin composite bond strength both before and after thermocycling. Four universal adhesives (G-premio bond universal, GPU; Clearfil Tri-S bond universal, CTB; Optibond Universal, OBU; Tetric N-bond universal; TNU), one adhesive (single bond 2; SB2), and one ceramic primer (Clearfil ceramic primer plus, CCP) were used in this study. MATERIALS AND METHODS: Zirconia discs were prepared and embedded in acrylic. Specimens were polished and sandblasted with alumina. The specimens were randomly divided into two groups (24 hours and the thermocycled), and each group was divided into six subgroups (n = 10), according to zirconia surfaces treatments: no Tx, CCP + SB2, GPU, CTB, OBU, TNU. An Ultradent mold was located on top of the treated zirconia surface. The resin composite was filled into the mold and then light-cured. A universal testing device was used to determine the shear bond strength. STATISTICAL ANALYSIS: The data were statistically analyzed using one-way ANOVA and Tukey's test. RESULTS: After water storage for 24 hours, the shear bond strengths were GPU > CCP + SB2 = CTB = OBU = TNU > no Tx (p < 0.05). After thermocycling, the shear bond strengths were CCP + SB2 = GPU = CTB = TNU > OBU > no Tx (p < 0.05). CONCLUSION: The universal adhesives containing 10-MDP exhibited the best performance in the shear bond strength of the zirconia/resin composite interface both before and after thermocycling.

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OBJECTIVE: The study aimed to evaluate the shear bond strength (SBS) of lithium disilicate glass-ceramic (LDGC) and resin cement (RC) using different surface treatments. MATERIALS AND METHODS: LDGC blocks (Vintage LD Press) were prepared, etched with 4.5% hydrofluoric acid, and randomly divided into seven groups (n = 10), depending on the surface treatments. The groups were divided as follows: 1) no surface treatment (control), 2) Silane Primer (KS), 3) Signum Ceramic Bond I (SGI), 4) Signum Ceramic Bond I/Signum Ceramic Bond II (SGI/SGII), 5) experimental silane (EXP), 6) experimental silane/Signum Ceramic Bond II (EXP/SGII), and 7) experimental silane/Adper Scotchbond Multi-purpose Adhesive (EXP/ADP). The specimens were cemented to resin composite blocks with resin cement and stored in water at 37 °C for 24 hours. The specimens underwent 5,000 thermal cycles and were subjected to the SBS test. Mode of failure was evaluated under the stereo microscope. STATISTICAL ANALYSIS: Data were analyzed with Welch ANOVA and Games-Howell post hoc tests (α = 0.05). RESULTS: The highest mean SBS showed in group EXP/ADP (45.49 ± 3.37 MPa); however, this was not significantly different from group EXP/SGII (41.38 ± 2.17 MPa) (p ≥ 0.05). The lowest SBS was shown in the control group (18.36 ± 0.69 MPa). This was not significantly different from group KS (20.17 ± 1.10 MPa) (p ≥ 0.05). CONCLUSIONS: The different surface treatments significantly affected the SBS value between LDGC and RC. The application of pure silane coupling agent with or without the application of an adhesive improved the SBS value and bond quality.

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This study examined the effectiveness of resin infiltration in inhibiting microleakage from artificial white-spot lesions (AWL) in enamel. Fifty sound extracted premolars were selected and randomly divided into five groups (n = 10 each). Group 1 included sound teeth. In contrast, an AWL was created in all specimens in groups 2 to 5, as follows-Group 2: AWL with no treatment; Group 3: AWL treated with resin infiltration; Group 4: AWL treated with resin infiltration and 5,000 cycles of thermocycling; Group 5: AWL treated with resin infiltration and 10,000 cycles of thermocycling. All specimens were then coated with nail varnish, except for a 4 × 4 mm2 area on the buccal surface (the measurement area), immersed in 2% methylene blue solution, and sectioned buccolingually. Microleakage was evaluated with a stereomicroscope. Data were analyzed by using the Kruskal-Wallis test and Bonferroni post-hoc correction. Application of resin infiltrant reduced microleakage in AWL. No microleakage was seen in Group 3, and differences between Groups 3, 4, and 5 were not significant (P > 0.05). The resin infiltration technique appears to aid in sealing enamel AWL and may help provide long-term protection against microleakage in enamel AWL.

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OBJECTIVE: The aim of this study was to evaluate the effect of neutralizing agents on the shear bond strength of hydrofluoric (HF)-etched porcelain in nonaging and aging conditions. SUBJECTS AND METHODS: One hundred and twenty feldspathic porcelain specimens were prepared and divided into six groups to undergo different surface conditioning methods-group 1: control; group 2: HF; group 3: HF + calcium hydroxide; group 4: HF + calcium carbonate; group 5: HF + calcium gluconate; and group 6: HF + ultrasonic. All samples were immersed in 37°C distilled water for 24 h. Half of the samples were thermocycled in water for 5,000 cycles. The shear bond strength test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. Data were statistically analyzed by two-way ANOVA and Tukey's multiple comparison test at a 95% confidence level. The surface micromorphology and surface elements were analyzed using scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX), respectively. RESULTS: The shear bond strengths of groups 2-6 were significantly higher than the control group in both aging and nonaging conditions (p < 0.05). There were no significant differences among all of the HF-etched porcelain groups (p > 0.05). SEM images of groups 2-6 illustrated similar patterns of irregularity on the specimen surfaces. Elemental analysis of EDX demonstrated identical elements on surfaces of specimens of groups 2-6. CONCLUSION: Within the limitations of this study, shear bond strength values between HF-etched porcelain, HF-etching followed by application of neutralizing agents, and HF-etching followed by ultrasonic cleaning were not significantly different in both nonaging and aging conditions.