Tool Sriamporn - Academia.edu (original) (raw)

Papers by Tool Sriamporn

Dental Materials Journal, 2014

The surface morphology and crystal structure change of dental zirconia after hydrofluoric acid (H... more The surface morphology and crystal structure change of dental zirconia after hydrofluoric acid (HF) etching were evaluated. Four groups of sintered zirconia specimens were 1) control group, 2) immersion in 9.5%HF at 25 o C for 1, 2, 3, or 24 h, 3) immersion in 9.5%HF at 80 o C for 1, 3, 5, or 30 min and 4) immersion in 48%HF at 25 o C for 30 or 60 min. The specimens were evaluated under SEM and XRD. The SEM analysis revealed changes in surface topography for all the HF-etched zirconia specimens. The irregularities surface increased with increasingly longer immersion times and higher etching solution temperatures. The XRD analysis of the HFetched zirconia specimens revealed the presence of a crystalline monoclinic phase along with a tetragonal form. It was concluded HF can etch dental zirconia ceramic, creating micro-morphological changes. Tetragonal-to-monoclinic phase transformation was induced on the etched zirconia surface.

European Journal of Dentistry

Objective The study aimed to evaluate the shear bond strength (SBS) of lithium disilicate glass-c... more 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/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 analyze...

This study aimed to evaluate the effect of different types of silane coupling agents on the shear... more This study aimed to evaluate the effect of different types of silane coupling agents on the shear bond strength between lithium disilicate glass ceramic and resin cement. Lithium disilicate disks (IPS e.max Press) were prepared and randomly assigned to six different groups (n=20) based on the type of silane used: control group (no treatment) and five silane-treated groups (Kerr silane primer, Monobond N, RelyX ceramic primer, experimental silane, and Single bond universal). Composite resin rods were luted to the prepared surfaces with resin cement. The samples were stored in distilled water (37C, 24 hrs) before shear bond strength test was performed. Data were analyzed by one-way ANOVA and Tukey’s HSD. RelyX ceramic primer and the experimental silane groups exhibited significantly higher shear bond strengths compared to other groups (p<0.05). The control group showed the lowest bond strength and was significantly different from other groups. It was found that the type of silane c...

This study examined the effects of silane coupling agents on lithium disilicate glass ceramic/res... more This study examined the effects of silane coupling agents on lithium disilicate glass ceramic/resin composite shear bond strength. Two silane coupling agents (RelyX ceramic primer, RX and Kerr silane, KS) and adhesive (Single bond2, SB) were used. Lithium disilicate disks were prepared and embedded in dental gypsum. The samples were randomly divided into six groups (n = 10) according to surface treatments: group1 (No tx), group2 (RX), group3 (SB), group4 (KS), group5 (RX+KS) and group6 (RX+SB). Silicone mold was placed on top of treated ceramic surface. Resin composite was filled into mold and then light-cured for 40 seconds. All bonded specimens were kept in distilled water at 37C for 24 hours and they were subjected to bond strength measurement using a universal testing machine. The data were statistically analyzed using oneway ANOVA and Tukey’s test. The bond strengths of group1 to group6 were 5.13(2.38), 16.36(3.54), 11.14(1.67), 10.49(2.85), 20.84(3.02) and 22.25(2.51) MPa, res...

This study evaluated the effect of chemical surface treatments on shear bond strength (SBS) of re... more This study evaluated the effect of chemical surface treatments on shear bond strength (SBS) of resin cement to the hybrid ceramic materials. Hybrid ceramic blocks (Shofu Block HC, Cerasmart, and Vita Enamic) were cut into slabs. The specimens of each hybrid ceramic material were randomly divided into 10 groups and each group was subdivided into 3 subgroups (n = 10) according to surface modification methods : no treatment, bonding agent (Adper Single Bond 2), Unifast TRAD Liquid + bonding agent, Meliodent Rapid Repair Liquid + bonding agent, Acetone 20 s + bonding agent, Acetone 40 s + bonding agent, Chloroform 20 s + bonding agent, Chloroform 40 s + bonding agent, Hybrid ceramic primer (HC Primer), and Hybrid ceramic primer + bonding agent. All specimens were luted using self-adhesive resin cement. SBS measurements were performed after 24 h of water storage. Results were analyzed using two-way analysis of variance (ANOVA) and Bonferroni post hoc test (P < 0.05). All surface treat...

The aim of this study was to evaluate the effect of cleansing agents on the shear bond strength o... more The aim of this study was to evaluate the effect of cleansing agents on the shear bond strength of resin cement and lithium disilicate ceramic after being contaminated with the hemostatic agent. The specimens were randomly divided into six groups (n=10) according to different treatments on ceramic surfaces: Group 1 without any surface treatment, Group 2 only applied a silane coupling agent, Group 3-6 also applied silane coupling agent, followed by a hemostatic agent (Viscostat® Clear) for 5 minutes and then cleaned with cleansing agents (Group 3 distilled water, Group 4 phosphoric acid, Group 5 chlorhexidine, Group 6 ethanol). All prepared specimens were bonded with resin cement (PanaviaTM V5). All bonded specimens were subjected to shear bond strength measurement using a universal testing machine. The data were statistically analyzed using oneway ANOVA and Tukey’s test (α=0.05). The results showed that the shear bond strength of Group 4-6 had no significant differences in shear bon...

This study examined the effect of curing mode in the universal adhesive on the shear bond strengt... more This study examined the effect of curing mode in the universal adhesive on the shear bond strength of zirconia and resin cement interface. Universal adhesive (Singlebond universal, SBU) and dual-cure activator (Singlebond universal dual-cure activator, DCA) were used. Forty zirconia disks were prepared and embedded in dental gypsum. The samples were randomly divided into four groups (n = 10) according to curing mode: group1 (No tx), group2 (SBU+LC), group3 (SBU+DCA+LC) and group4 (SBU+DCA). Silicone mold was placed on top of the treated zirconia surface. Resin cement was filled into the mold and subsequently stored in a yellow box for 30 minutes. All bonded specimens were kept in distilled water at 37C for 24 hours and they were subjected to bond strength measurement using a universal testing machine. The data were statistically analyzed using one-way ANOVA and Tukey’s test. The shear bond strengths of group1 to group4 were 6.13±2.45, 25.42±3.09, 24.26±1.98 and 17.38±2.76 MPa, respe...

Objective To investigate the effect of Dycal on the shear bond strength of four luting resins. Ma... more Objective To investigate the effect of Dycal on the shear bond strength of four luting resins. Materials and Methods One hundred twenty extracted human molars were ground to flat dentin surface and were then randomly divided into three groups with forty teeth each. Group 1: the dentin surface was not covered with Dycal (control group). Group 2 and 3: the dentin surface was covered with Dycal for 7 and 28 days, respectively. Each group was divided into 4 subgroups based on luting resins (Variolink N, Panavia F 2.0, RelyX U200 and MaxCem Elite). After reaching the cover time, Dycal was removed and dentin was cleaned. The resin composite rods were bonded on each group with different resin cements. All specimens were kept in distilled water at 37°C for 24 hours and they were then subjected to shear bond strength test using universal testing machine at crosshead speed 0.5 mm/minute. The data were statistically analyzed by Two-way analysis of variance (ANOVA) and the Tukey’s multiple co...

The aim of this study was to investigate the effect of treating the etched/unetched lithium disil... more The aim of this study was to investigate the effect of treating the etched/unetched lithium disilicate surface with various types of silane coupling agents on the contact angle measurement. One hundred fifty lithium disilicate disks were prepared to dimensions of 10 millimeters in diameter and 3 millimeters in height. The samples were randomly divided into two groups: hydrofluoric etched and unetched lithium disilicate surfaces before silane application. Each group was further divided into five subgroups, according to type of silane coupling agent used to treat the prepared surfaces, no treatment (control), Kerr silane primer, Monobond N, Rely X ceramic primer and an experimental silane, respectively. The contact angles between deionized water and the prepared surface were measured using a contact angle tester via the sessile drop method. Data were statistically analyzed using Two-way analysis of variance and Tukey’s multiple comparison tests (α=0.05). The results showed that in the...

Objective To investigate the effect of Dycal on shear bond strengths of four luting resins. Mater... more Objective To investigate the effect of Dycal on shear bond strengths of four luting resins. Materials and methods One hundred twenty extracted human permanent molars were ground to flat dentin surface and were then randomly divided into three groups with forty teeth each. Group 1: dentin surfaces were not covered with Dycal (control group). Group 2 and 3: dentin surfaces were covered with Dycal for 7 and 28 days, respectively. Each group was divided into 4 subgroups based on luting resins (Variolink N, Panavia F 2.0, RelyX U200 and MaxCem Elite). After reaching the cover time, Dycal was removed and dentin was cleaned. The resin composite rods were bonded on each group with different resin cements. All specimens were kept in distilled water at 37°C for 24 hours and they were then subjected to shear bond strength test using a universal testing machine at crosshead speed 0.5 mm/minute. The data were statistically analyzed by Two-way analysis of variance (ANOVA) and the Tukeyus multiple...

European Journal of Dentistry

Objective The aim of this study was to evaluate the effect of neutralizing agents on the shear bo... more 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 ...

Chulalongkorn University Dental Journal วารสารทันตแพทยศาสตร์ จุฬาลงกรณ์มหาวิทยาลัย, May 9, 2013

Objective To study the mechanical and physical properties of commercially available orthodontic e... more Objective To study the mechanical and physical properties of commercially available orthodontic elastomeric ligatures. Materials and Methods For the mechanical test, the elastomeric ligatures were divided into seven groups (n=20 for each group) according to commercial companies. The initial tensile force and the force after immersion in distilled water for 1, 7 and 28 days of specimens were measured by Lloyd Universal Testing Machine with the method modified form ISO 21606. For the surface hardness test, 10 specimens from each group were measured for the initial surface hardness by Durometer Shore A. They were then immersed in distilled water for 1, 7, and 28 days and measured for the surface hardness again at each time period. In the case of color staining resistance test, the specimens were immersed in tea or coffee solution for 1 hour and 1 day and the different color value (Δ E) was measured by spectrophotometer at each time interval. One way ANOVA and Bonferroni multiple comparisons were used to analyze the data from the tensile force and the surface hardness tests. Results The results showed that the tensile force of elastomeric ligatures of all groups after immersion in distilled water for 1, 7, and 28 days was significantly lower than the initial force ( p 0.05) when compared among the specimens immersed in the distilled water at different time periods. The surface hardness Shore A of all groups was not significantly different ( p >0.05) at every immersion time. For the color staining resistance, the specimens showed the difference color value (Δ E) higher than 3.3 after 1 hour of immersion in tea or coffee solution. Conclusion The tensile force of the elastomeric ligature was decreased after 1 day of immersion in distilled water and the surface hardness of specimens was not altered at every immersion time. In addition,the specimens demonstrated the color change after 1 hour of immersion in tea or coffee solution. (CU Dent J. 2009;32:11-22) Key words : color staining resistance; elastomeric ligature; surface hardness Shore A; tensile force

Degree of conversion (DC) of luting resins is one of the important factors that affects clinical ... more Degree of conversion (DC) of luting resins is one of the important factors that affects clinical properties of materials. Objective: The purpose of this study was to determine the DC of four dual-cured luting resins with and without visible light irradiation at different storage time periods. Methods: Four dual-cured luting resins, RelyX Unicem Applicap (3M-ESPE), SpeedCem (Ivoclar Vivadent), Clearfil SA cement (Kuraray), and NX3 Nexus (Kerr) were used in this study. Ten specimens with 0.3 mm thickness in each group were irradiated with Optilux-501 with 800 mW/cm2 for 40 s. DC was determined by Fourier transform infrared spectroscopy (FT-IR) immediately after curing, 30 min, 1 h, and 3 h, 24 h, 3 d and 7 d after curing. For without irradiated luting resin groups (polymerization by chemical cure only), Ten specimens were prepared with 0.3 mm thickness in each group and then the DC was evaluated at the same storage time periods as describe above. The mean values of DC were statistical...

This study evaluated the effect of a dual cure activator (DCA) on the degree of the conversion of... more This study evaluated the effect of a dual cure activator (DCA) on the degree of the conversion of self-adhesive resin cements (SARCs) without light activation by the mean of microhardness testing. Two hundred and seventy molds were prepared from silicone with a circular hole (5 mm diameter x 2 mm thick). The specimens were divided into the control and test groups. Each group comprised 27 specimens; three specimens for each function time of nine intervals. Five SARCs were used, and each of them was placed into the mold and covered with a mylar strip with the applied DCA. No DCA on the mylar strip served as a control. All specimens were stored in darkness in an incubator under a temperature of 37°C without light activation in each functional time. The measurements were tested by using Vickers hardness tester. The data were statistically analyzed using two-way repeated measure ANOVA followed by Bonferroni comparison tests (α=0.05). The overall results showed that the microhardness valu...

Objective: To evaluate the effects of dentine contaminated with eugenol liquid on the microtensil... more Objective: To evaluate the effects of dentine contaminated with eugenol liquid on the microtensile bond strength of three resin cements Methods: A self adhesive system, Rely X Unicem, and self-etching systems, Panavia F 2.0 and NX3 , were used. The occlusal enamel and superficial dentine of thirty non-carious human third molars were removed and then the dentine surface was ground with silicon carbide paper. Half of the prepared teeth were applied with eugenol liquid three times on the dentine surface then they were kept in plastic container at 37 degree celcius for 24 hours. The cylindrical resin composite blocks (8 mm in diameter and 6 mm in thickness) were luted to human dentine using resin cements (RelyX Unicem, Panavia F2.0, NX3) with/without pre-treatment by eugenol liquid. After storage in water for 24 hours, the bonded teeth were sectioned into 1 mm x 1 mm composite-dentine beams according to the non-trimming technique for the microtensile testing. The specimens were then sub...

Dental Materials Journal, 2014

The surface morphology and crystal structure change of dental zirconia after hydrofluoric acid (H... more The surface morphology and crystal structure change of dental zirconia after hydrofluoric acid (HF) etching were evaluated. Four groups of sintered zirconia specimens were 1) control group, 2) immersion in 9.5%HF at 25 o C for 1, 2, 3, or 24 h, 3) immersion in 9.5%HF at 80 o C for 1, 3, 5, or 30 min and 4) immersion in 48%HF at 25 o C for 30 or 60 min. The specimens were evaluated under SEM and XRD. The SEM analysis revealed changes in surface topography for all the HF-etched zirconia specimens. The irregularities surface increased with increasingly longer immersion times and higher etching solution temperatures. The XRD analysis of the HFetched zirconia specimens revealed the presence of a crystalline monoclinic phase along with a tetragonal form. It was concluded HF can etch dental zirconia ceramic, creating micro-morphological changes. Tetragonal-to-monoclinic phase transformation was induced on the etched zirconia surface.

European Journal of Dentistry

Objective The study aimed to evaluate the shear bond strength (SBS) of lithium disilicate glass-c... more 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/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 analyze...

This study aimed to evaluate the effect of different types of silane coupling agents on the shear... more This study aimed to evaluate the effect of different types of silane coupling agents on the shear bond strength between lithium disilicate glass ceramic and resin cement. Lithium disilicate disks (IPS e.max Press) were prepared and randomly assigned to six different groups (n=20) based on the type of silane used: control group (no treatment) and five silane-treated groups (Kerr silane primer, Monobond N, RelyX ceramic primer, experimental silane, and Single bond universal). Composite resin rods were luted to the prepared surfaces with resin cement. The samples were stored in distilled water (37C, 24 hrs) before shear bond strength test was performed. Data were analyzed by one-way ANOVA and Tukey’s HSD. RelyX ceramic primer and the experimental silane groups exhibited significantly higher shear bond strengths compared to other groups (p<0.05). The control group showed the lowest bond strength and was significantly different from other groups. It was found that the type of silane c...

This study examined the effects of silane coupling agents on lithium disilicate glass ceramic/res... more This study examined the effects of silane coupling agents on lithium disilicate glass ceramic/resin composite shear bond strength. Two silane coupling agents (RelyX ceramic primer, RX and Kerr silane, KS) and adhesive (Single bond2, SB) were used. Lithium disilicate disks were prepared and embedded in dental gypsum. The samples were randomly divided into six groups (n = 10) according to surface treatments: group1 (No tx), group2 (RX), group3 (SB), group4 (KS), group5 (RX+KS) and group6 (RX+SB). Silicone mold was placed on top of treated ceramic surface. Resin composite was filled into mold and then light-cured for 40 seconds. All bonded specimens were kept in distilled water at 37C for 24 hours and they were subjected to bond strength measurement using a universal testing machine. The data were statistically analyzed using oneway ANOVA and Tukey’s test. The bond strengths of group1 to group6 were 5.13(2.38), 16.36(3.54), 11.14(1.67), 10.49(2.85), 20.84(3.02) and 22.25(2.51) MPa, res...

This study evaluated the effect of chemical surface treatments on shear bond strength (SBS) of re... more This study evaluated the effect of chemical surface treatments on shear bond strength (SBS) of resin cement to the hybrid ceramic materials. Hybrid ceramic blocks (Shofu Block HC, Cerasmart, and Vita Enamic) were cut into slabs. The specimens of each hybrid ceramic material were randomly divided into 10 groups and each group was subdivided into 3 subgroups (n = 10) according to surface modification methods : no treatment, bonding agent (Adper Single Bond 2), Unifast TRAD Liquid + bonding agent, Meliodent Rapid Repair Liquid + bonding agent, Acetone 20 s + bonding agent, Acetone 40 s + bonding agent, Chloroform 20 s + bonding agent, Chloroform 40 s + bonding agent, Hybrid ceramic primer (HC Primer), and Hybrid ceramic primer + bonding agent. All specimens were luted using self-adhesive resin cement. SBS measurements were performed after 24 h of water storage. Results were analyzed using two-way analysis of variance (ANOVA) and Bonferroni post hoc test (P < 0.05). All surface treat...

The aim of this study was to evaluate the effect of cleansing agents on the shear bond strength o... more The aim of this study was to evaluate the effect of cleansing agents on the shear bond strength of resin cement and lithium disilicate ceramic after being contaminated with the hemostatic agent. The specimens were randomly divided into six groups (n=10) according to different treatments on ceramic surfaces: Group 1 without any surface treatment, Group 2 only applied a silane coupling agent, Group 3-6 also applied silane coupling agent, followed by a hemostatic agent (Viscostat® Clear) for 5 minutes and then cleaned with cleansing agents (Group 3 distilled water, Group 4 phosphoric acid, Group 5 chlorhexidine, Group 6 ethanol). All prepared specimens were bonded with resin cement (PanaviaTM V5). All bonded specimens were subjected to shear bond strength measurement using a universal testing machine. The data were statistically analyzed using oneway ANOVA and Tukey’s test (α=0.05). The results showed that the shear bond strength of Group 4-6 had no significant differences in shear bon...

This study examined the effect of curing mode in the universal adhesive on the shear bond strengt... more This study examined the effect of curing mode in the universal adhesive on the shear bond strength of zirconia and resin cement interface. Universal adhesive (Singlebond universal, SBU) and dual-cure activator (Singlebond universal dual-cure activator, DCA) were used. Forty zirconia disks were prepared and embedded in dental gypsum. The samples were randomly divided into four groups (n = 10) according to curing mode: group1 (No tx), group2 (SBU+LC), group3 (SBU+DCA+LC) and group4 (SBU+DCA). Silicone mold was placed on top of the treated zirconia surface. Resin cement was filled into the mold and subsequently stored in a yellow box for 30 minutes. All bonded specimens were kept in distilled water at 37C for 24 hours and they were subjected to bond strength measurement using a universal testing machine. The data were statistically analyzed using one-way ANOVA and Tukey’s test. The shear bond strengths of group1 to group4 were 6.13±2.45, 25.42±3.09, 24.26±1.98 and 17.38±2.76 MPa, respe...

Objective To investigate the effect of Dycal on the shear bond strength of four luting resins. Ma... more Objective To investigate the effect of Dycal on the shear bond strength of four luting resins. Materials and Methods One hundred twenty extracted human molars were ground to flat dentin surface and were then randomly divided into three groups with forty teeth each. Group 1: the dentin surface was not covered with Dycal (control group). Group 2 and 3: the dentin surface was covered with Dycal for 7 and 28 days, respectively. Each group was divided into 4 subgroups based on luting resins (Variolink N, Panavia F 2.0, RelyX U200 and MaxCem Elite). After reaching the cover time, Dycal was removed and dentin was cleaned. The resin composite rods were bonded on each group with different resin cements. All specimens were kept in distilled water at 37°C for 24 hours and they were then subjected to shear bond strength test using universal testing machine at crosshead speed 0.5 mm/minute. The data were statistically analyzed by Two-way analysis of variance (ANOVA) and the Tukey’s multiple co...

The aim of this study was to investigate the effect of treating the etched/unetched lithium disil... more The aim of this study was to investigate the effect of treating the etched/unetched lithium disilicate surface with various types of silane coupling agents on the contact angle measurement. One hundred fifty lithium disilicate disks were prepared to dimensions of 10 millimeters in diameter and 3 millimeters in height. The samples were randomly divided into two groups: hydrofluoric etched and unetched lithium disilicate surfaces before silane application. Each group was further divided into five subgroups, according to type of silane coupling agent used to treat the prepared surfaces, no treatment (control), Kerr silane primer, Monobond N, Rely X ceramic primer and an experimental silane, respectively. The contact angles between deionized water and the prepared surface were measured using a contact angle tester via the sessile drop method. Data were statistically analyzed using Two-way analysis of variance and Tukey’s multiple comparison tests (α=0.05). The results showed that in the...

Objective To investigate the effect of Dycal on shear bond strengths of four luting resins. Mater... more Objective To investigate the effect of Dycal on shear bond strengths of four luting resins. Materials and methods One hundred twenty extracted human permanent molars were ground to flat dentin surface and were then randomly divided into three groups with forty teeth each. Group 1: dentin surfaces were not covered with Dycal (control group). Group 2 and 3: dentin surfaces were covered with Dycal for 7 and 28 days, respectively. Each group was divided into 4 subgroups based on luting resins (Variolink N, Panavia F 2.0, RelyX U200 and MaxCem Elite). After reaching the cover time, Dycal was removed and dentin was cleaned. The resin composite rods were bonded on each group with different resin cements. All specimens were kept in distilled water at 37°C for 24 hours and they were then subjected to shear bond strength test using a universal testing machine at crosshead speed 0.5 mm/minute. The data were statistically analyzed by Two-way analysis of variance (ANOVA) and the Tukeyus multiple...

European Journal of Dentistry

Objective The aim of this study was to evaluate the effect of neutralizing agents on the shear bo... more 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 ...

Chulalongkorn University Dental Journal วารสารทันตแพทยศาสตร์ จุฬาลงกรณ์มหาวิทยาลัย, May 9, 2013

Objective To study the mechanical and physical properties of commercially available orthodontic e... more Objective To study the mechanical and physical properties of commercially available orthodontic elastomeric ligatures. Materials and Methods For the mechanical test, the elastomeric ligatures were divided into seven groups (n=20 for each group) according to commercial companies. The initial tensile force and the force after immersion in distilled water for 1, 7 and 28 days of specimens were measured by Lloyd Universal Testing Machine with the method modified form ISO 21606. For the surface hardness test, 10 specimens from each group were measured for the initial surface hardness by Durometer Shore A. They were then immersed in distilled water for 1, 7, and 28 days and measured for the surface hardness again at each time period. In the case of color staining resistance test, the specimens were immersed in tea or coffee solution for 1 hour and 1 day and the different color value (Δ E) was measured by spectrophotometer at each time interval. One way ANOVA and Bonferroni multiple comparisons were used to analyze the data from the tensile force and the surface hardness tests. Results The results showed that the tensile force of elastomeric ligatures of all groups after immersion in distilled water for 1, 7, and 28 days was significantly lower than the initial force ( p 0.05) when compared among the specimens immersed in the distilled water at different time periods. The surface hardness Shore A of all groups was not significantly different ( p >0.05) at every immersion time. For the color staining resistance, the specimens showed the difference color value (Δ E) higher than 3.3 after 1 hour of immersion in tea or coffee solution. Conclusion The tensile force of the elastomeric ligature was decreased after 1 day of immersion in distilled water and the surface hardness of specimens was not altered at every immersion time. In addition,the specimens demonstrated the color change after 1 hour of immersion in tea or coffee solution. (CU Dent J. 2009;32:11-22) Key words : color staining resistance; elastomeric ligature; surface hardness Shore A; tensile force

Degree of conversion (DC) of luting resins is one of the important factors that affects clinical ... more Degree of conversion (DC) of luting resins is one of the important factors that affects clinical properties of materials. Objective: The purpose of this study was to determine the DC of four dual-cured luting resins with and without visible light irradiation at different storage time periods. Methods: Four dual-cured luting resins, RelyX Unicem Applicap (3M-ESPE), SpeedCem (Ivoclar Vivadent), Clearfil SA cement (Kuraray), and NX3 Nexus (Kerr) were used in this study. Ten specimens with 0.3 mm thickness in each group were irradiated with Optilux-501 with 800 mW/cm2 for 40 s. DC was determined by Fourier transform infrared spectroscopy (FT-IR) immediately after curing, 30 min, 1 h, and 3 h, 24 h, 3 d and 7 d after curing. For without irradiated luting resin groups (polymerization by chemical cure only), Ten specimens were prepared with 0.3 mm thickness in each group and then the DC was evaluated at the same storage time periods as describe above. The mean values of DC were statistical...

This study evaluated the effect of a dual cure activator (DCA) on the degree of the conversion of... more This study evaluated the effect of a dual cure activator (DCA) on the degree of the conversion of self-adhesive resin cements (SARCs) without light activation by the mean of microhardness testing. Two hundred and seventy molds were prepared from silicone with a circular hole (5 mm diameter x 2 mm thick). The specimens were divided into the control and test groups. Each group comprised 27 specimens; three specimens for each function time of nine intervals. Five SARCs were used, and each of them was placed into the mold and covered with a mylar strip with the applied DCA. No DCA on the mylar strip served as a control. All specimens were stored in darkness in an incubator under a temperature of 37°C without light activation in each functional time. The measurements were tested by using Vickers hardness tester. The data were statistically analyzed using two-way repeated measure ANOVA followed by Bonferroni comparison tests (α=0.05). The overall results showed that the microhardness valu...

Objective: To evaluate the effects of dentine contaminated with eugenol liquid on the microtensil... more Objective: To evaluate the effects of dentine contaminated with eugenol liquid on the microtensile bond strength of three resin cements Methods: A self adhesive system, Rely X Unicem, and self-etching systems, Panavia F 2.0 and NX3 , were used. The occlusal enamel and superficial dentine of thirty non-carious human third molars were removed and then the dentine surface was ground with silicon carbide paper. Half of the prepared teeth were applied with eugenol liquid three times on the dentine surface then they were kept in plastic container at 37 degree celcius for 24 hours. The cylindrical resin composite blocks (8 mm in diameter and 6 mm in thickness) were luted to human dentine using resin cements (RelyX Unicem, Panavia F2.0, NX3) with/without pre-treatment by eugenol liquid. After storage in water for 24 hours, the bonded teeth were sectioned into 1 mm x 1 mm composite-dentine beams according to the non-trimming technique for the microtensile testing. The specimens were then sub...