COMPOSITE RESIN BOND STRENGTH TO ETCHED DENTINWITH ONE SELF PRIMING ADHESIVE
Abstract
Introduction. The purpose of this study was to compare shear bond strength of composite resins to etched dentin in both dry and wet dentin surface with active and inactive application of a single-bottle adhesive resin (Single Bond, 3M Dental products).
Methods. Fourthy four intact human extracted molars and premolars teeth were selected. The facial surfaces of the teeth were grounded with diamond bur to expose dentin. Then specimens were divided into four groups of 11 numbers (9 Molars and 2 Premolars). All the samples were etched with Phosphoric Acid Gel 35% and then rinsed for 10 seconds. The following stages were carried out for each group: Group I (Active-Dry): After rinsing, air drying of dentin surface for 15 seconds, active priming of adhesive resin for 15 seconds, air drying for 5 seconds, the adhesive resin layer was light cured for 10 seconds. Group III (Inactive-Dry):After rinsing, air drying of dentin surface for 15 seconds, adhesive resin was applied and air dryied for 5 seconds, the adhesive layer was light cured for 10 seconds. Group III (Active-Wet):After rinsing, removal of excess water of dentin surface with a cotton roll, active priming of adhesive resin for 15 seconds and air drying for 5 seconds, the adhesive layer was light cured for 10 seconds. Group IV (Inactive-Wet):After rinsing, removal of excess water of dentin surface with a cotton roll, the adhesive resin was applied and air dryied for 5 seconds and then cured for 10 seconds. After adhesive resin application, composite resin (Z250, 3M Dental products) was applied on prepared surface with cylindrical molds (with internal diameter of 2.8mm, & height of 5mm) and light-cured for 100 seconds (5x20s). The samples were then thermocycled. They were located in 6±3c water .temperature for 10 seconds and then 15 seconds in inviromental temperature, 10s in 55±3c water temperature and then were located at room temperature for 15s. This test was repeated for 100s. All of the specimens were then mounted in acrylic molds. After thermocycling and mounting of the samples, shear forces were applied on the restorations by universal test machine (Dartec) with cross head speed of 5mm/min. The maximum shear bond strength (MPa) was calculated. Results. The mean shear bond strengths and standard deviations for group I (active-dry),II (nonactive - dry), III (active-wet) and IV (nonactive-wet) were 11.55±8.59, 11.02 ± 4.1, 23.38±8.09 and 26.34 ± 6.97MPa respectively.
Discussion. Results indicated that there was a statistically significant difference between groups I,II and groups III,IV .In the other hand, groups III and IV have shown a good and sufficient mean shear bond strength which means the wettness of dentin surface, has a significant role on enhancement of shear bond strength of Single - Bond to etched dentin and the application of active or inactive priming dose not have a significant role on enhancement of the bond strength and can be deleted as an aditional stage. 93% of the total failure modes were adhesive, 4.5% were mixed (dentin-adhesive) and 2.5% were mixed (composite-adhesive).
Methods. Fourthy four intact human extracted molars and premolars teeth were selected. The facial surfaces of the teeth were grounded with diamond bur to expose dentin. Then specimens were divided into four groups of 11 numbers (9 Molars and 2 Premolars). All the samples were etched with Phosphoric Acid Gel 35% and then rinsed for 10 seconds. The following stages were carried out for each group: Group I (Active-Dry): After rinsing, air drying of dentin surface for 15 seconds, active priming of adhesive resin for 15 seconds, air drying for 5 seconds, the adhesive resin layer was light cured for 10 seconds. Group III (Inactive-Dry):After rinsing, air drying of dentin surface for 15 seconds, adhesive resin was applied and air dryied for 5 seconds, the adhesive layer was light cured for 10 seconds. Group III (Active-Wet):After rinsing, removal of excess water of dentin surface with a cotton roll, active priming of adhesive resin for 15 seconds and air drying for 5 seconds, the adhesive layer was light cured for 10 seconds. Group IV (Inactive-Wet):After rinsing, removal of excess water of dentin surface with a cotton roll, the adhesive resin was applied and air dryied for 5 seconds and then cured for 10 seconds. After adhesive resin application, composite resin (Z250, 3M Dental products) was applied on prepared surface with cylindrical molds (with internal diameter of 2.8mm, & height of 5mm) and light-cured for 100 seconds (5x20s). The samples were then thermocycled. They were located in 6±3c water .temperature for 10 seconds and then 15 seconds in inviromental temperature, 10s in 55±3c water temperature and then were located at room temperature for 15s. This test was repeated for 100s. All of the specimens were then mounted in acrylic molds. After thermocycling and mounting of the samples, shear forces were applied on the restorations by universal test machine (Dartec) with cross head speed of 5mm/min. The maximum shear bond strength (MPa) was calculated. Results. The mean shear bond strengths and standard deviations for group I (active-dry),II (nonactive - dry), III (active-wet) and IV (nonactive-wet) were 11.55±8.59, 11.02 ± 4.1, 23.38±8.09 and 26.34 ± 6.97MPa respectively.
Discussion. Results indicated that there was a statistically significant difference between groups I,II and groups III,IV .In the other hand, groups III and IV have shown a good and sufficient mean shear bond strength which means the wettness of dentin surface, has a significant role on enhancement of shear bond strength of Single - Bond to etched dentin and the application of active or inactive priming dose not have a significant role on enhancement of the bond strength and can be deleted as an aditional stage. 93% of the total failure modes were adhesive, 4.5% were mixed (dentin-adhesive) and 2.5% were mixed (composite-adhesive).
Keywords
Dentin, Bonding, Active Priming, lnactive Priming, Single-Bond