Showing 2 results for Soltanmohamadi borujeni
Elahe Soltanmohamadi Borujeni, Fatemeh Babaahmadi, Mohammad Aghaali, Ali Saleh, Aida Mehdipour,
Volume 33, Issue 221 (5-2023)
Abstract
Background and purpose: Lasers are of great importance in dentistry and have shown positive results in surface conditioning of ceramic brackets. The aim of this study was to compare the effect of two surface conditioning method, Nd:YAG laser and sandblasting on shear bind strength (SBS) and (adhesive remnant index (ARI).
Materials and methods: This experimental study was conducted in six groups of zirconia blocks to get prepared by laser (LG1-LG2-LG3) or sandblast (SG4-SG5-SG6). Two debonding methods, including conventional (LG3-SG3) and Nd:YAG laser (LG2-SG2) methods were used for zirconia blocks. SBS and ARI indices were compared between the two methods using ANOVA and post-hoc test.
Results: The mean SBS did not show significant difference between LG1 and SG4 groups (8.2±2.04 and 7.1±1.5, respectively, P=0.228). ARI did not show significant difference between LG2 (3.1±0.8) and SG5 (3.5±0.7) groups (P=0.129) and between LG3 and SG6 (2.3±0.7 and 2.7±0.5, respectively, P=0.219). ARI was found to be significantly different between LG2 and LG3 (30.1±0.8 and 2.3±0.7, respectively, P =0.011) and between SG5 (3.5±0.7) and SG6 (2.7± 0.5) (P=0.024).
Conclusion: Nd:YAG laser can be considered a suitable alternative for zirconia surface conditioning and debonding ceramic brackets from zirconia crowns.
Elahe Soltanmohamadi Borujeni, Sepehr Sobhani Kazemi,
Volume 34, Issue 242 (2-2025)
Abstract
Background and purpose: Due to the relatively high cost of cosmetic restorations with indirect composite resins, the time required for their complete replacement, and, in some cases, the need for significant tooth structure removal, repairing these restorations may sometimes be a more appropriate approach. This study aimed to investigate and compare the effects of different surface preparation methods on the shear bond strength between indirect and direct composite resins.
Materials and methods: In this study, 102 indirect composite resin blocks of Ivoclar SR Nexco Paste were fabricated and assigned to three groups (n = 34) based on the preparation method. Group 1: roughening and etching with 37% phosphoric acid; Group 2: roughening and etching with 9.5% hydrofluoric acid; Group 3: air abrasion with 50-μm aluminum oxide particles. A total of 500 thermal cycles were performed before the repair process, and surface preparations were carried out. After applying the adhesive in all groups, the samples were repaired using the direct Ivoclar Heliomolar composite resin. The samples were then subjected to fracture by an Instron machine at a speed of 0.5 mm/min, and the shear bond strength was recorded. The data were then converted to MPa and evaluated using one-way ANOVA and the Tukey test.
Results: The highest shear bond strength was recorded in Group 2 (mean± SD = 24.64± 2.28), and the lowest bond strength was recorded in Group 1 (mean± SD= 10.31± 1.67).
Conclusion: In this study, preparation with hydrofluoric acid resulted in higher shear bond strength compared to phosphoric acid and air abrasion.
