الفهرس 
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Abstract
The objective of the following research was to examine the impact of different surface approaches on the post-space dentin using 10% citric acid, 10% sodium ascorbate, and diode laser on the elemental dentin composition, chemical alteration induced, and fiber posts’ bond strength when cemented using self-adhesive resin cement.
Seventy-two mandibular second premolars with a single root were collected, endodontically treated, and then post spaces were prepared. group I: 0.9% saline (control); group II: 10% citric acid for 15 seconds then washed for 30 seconds using distilled water; group III: 10% sodium ascorbate solution for ten minutes then washed for 30 seconds with distilled water; group IV: diode laser (970 nm) was applied to the specimen roots’: 1.5W output power, 20 Hz frequency, 238.85 J/cm2, in a continuous mode for a period of twenty seconds. Each group was further divided into subgroups A and B, and nine specimens from each subgroup underwent analyses (EDX elemental analysis and push-out bond test).
Each specimen in (subgroup A) was split longitudinally in the buccolingual direction into two halves for EDX elemental analysis. The elemental analysis of the following elements C, O, Mg, Ca, and P was identified at three points along the root canal, coronal, middle, and apical regions for each half.
In (subgroup B), nine fiber posts were introduced and cemented to the prepared post spaces. Each specimen was subsequently separated into three-thirds (coronal, middle, and apical) and
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subjected to a push-out bond strength test using a universal testing machine. Using the stereomicroscope, all debonded specimens were examined in order to determine the failure mode.
The results were then tabulated and statistically analysed. group II (Citric acid) showed statistically significant mineral loss and changes in Ca, P, O, and Mg contents of root dentin (P 0.05), as well as an increase in C content (P> 0.05), when compared to other groups. In comparison with group I (control), group III (Sodium Ascorbate) and group IV (Diode Laser) exhibited statistically significant changes in the mineral content of Ca, P, O, and Mg (P > 0.05).
In comparison to all other groups, group III’s bond strength (13.45± 4.24 MPa) was statistically significantly higher (p >0.05). group II (13.45 ±4.24) MPa and group IV (9.75± 2.76) MPa demonstrated statistically significant improvements in bond strength compared to group I (3.93± 1.80) MPa.