An Evaluation of Different Materials for Surface Treatment on Microleakage of Repaired Composite Resin Restoration

Abstract

Aims:To evaluate the effect of different surface treatment on the microleakage of repaired CI V composite resin restoration. Materials and methods: This study was performed in vitro on 20 caries free premolar teeth. Standardized class V cavity preparation on buccal and lingual surfaces of each tooth was done, forty cavities cleaned with distilled water and dried, then the cavities were filled with the composite. After that, all teeth were stored in normal saline for 3 months, so that the filling become old then remove 1mm of composite from all cavities. The cavities were divided into four groups. The first two groups were treated with 37% phosphoric acid. The other groups treated with 9% hydrofluoric acid the groups II and IV were treated with silane coupling agent, then all cavities were filled with composite after 5 th generation bonding agent were applied .The teeth were stored for one week after that the Samples were thermocycled and immersed in methylene blue dye, The samples were sectioned, and examined using stereomicroscope. Results: Samples treated with silane coupling agent showed less microleakage than those without silanation. There was highly significant difference between samples acid etched using hydrofluoric acid with those etched with phosphoric acid. Conclusions: Silane coupling agent and the hydrofluoric acid significantly decreased microleakage of repaired CI V composite resin restoration.

Shear Bond Strength of Repaired Composite Using Single Bond Adhesive

“…On the other hand, SBS values for composite resin restorations repair varies greatly according to several factors such as; composition of the composite material, surface pretreatment protocol, aging method etc. However, it is clearly stated in the literature that intermediate bonding agents and salinization could enhance bonding during repairing composite resin restorations [21][22][23][24][25]31,32]. Our results confirm the previous stated data about the importance of bonding and silanization steps in composite repairs [14,33,34].…”

“…Silane treatment of the exposed filler particles in the composite matrix results in the formation of siloxane bonds when the silanol groups condense with similar groups, and at the same time the methacrylate groups of the organosilane compound form covalent bonds with the resin when it is polymerized [7,20]. Silanization proved to give better bonding results when bonds chemically the aged post-cured composite with fresh composite [7,15,[21][22][23].…”

Evaluating Various Preparation Protocols on the Shear Bond Strength of Repaired Composite

“…Hydrofluoric acid attacks the silica phase of composite, producing a retentive surface for micromechanical bonding. 28…”

“…Silanization proved to give better bonding results. 5,15,[26][27][28] Intermediate adhesives and bonding agents would improve the strength of the repaired composite and enhance bonding significantly between aged composites and fresh composite layers. 14,16,18,19,29,30 However, not all general practitioners have additional tools, such as chairside air abrasion or silica coating devices.…”