Please use this identifier to cite or link to this item:
|Type:||Artigo de periódico|
|Title:||Influence of thermal and mechanical load cycling on microtensile bond strengths of total and self-etching adhesive systems|
|Abstract:||This study evaluated the influence of different thermal (TC) and mechanical (MC) cycling protocols on microtensile bond strength (pTBS) to cervical dentin margins of Class II restorations using two total-etch (TE) adhesives and one self-etching (SE) primer. Class II slot cavities were prepared on the mesial surfaces of 168 bovine incisors and were divided into three groups according to the bonding system used: Single Bond, OptiBond Solo Plus and Clearfil SE Bond. All cavities were restored with Filtek Z250 composite. Following restorative procedures, the restored teeth were allocated to seven subgroups (n=8) according to the thermal/mechanical protocol performed: G1-control (no cycling), G2-100,000 MC, G3-200,000 MC, G4-500,000 MC, G5-100,000 MC+1,000 TC, G6-200,000 MC+1,000 TC, G7-500,000 MC+1,000 TC. TC was performed using 5 TC and 55 TC baths, with a dwell time of 60 seconds in each bath. MC was achieved with an axial force of 80 N at 2 cycles/second. The restorations were sectioned perpendicular to the cervical bonded interface into two 0.8-1-mm thick slabs. The slabs were trimmed at the interface to obtain a cross-sectional surface area of 0.8-1 mm(2). All specimens were then subjected to mu TBS (v=0.5 mm/minute). Fracture mode analysis was performed using SEM. Bond strength mean values (AWa) were analyzed with ANOVA 3-way and Tukey's test (alpha=5%). Dunnett's test was used to compare tested groups against Control groups of each adhesive system (alpha=5%). SE primer presented lower mean bond strength values when compared to TE adhesives (p=0.05). In addition, specimens restored with the SE primer did not resist to the 200,000 and 500,000 MC associated with TC. The application of 100,000 MC did not present a significant decrease in bond strength when compared to the control. Mixed failures were predominant for all groups. The higher the amount of thermal/mechanical cycles, the greater the number of mixed failures and the lower the percentage of adhesive failures.|
|Editor:||Operative Dentistry Inc|
|Appears in Collections:||Unicamp - Artigos e Outros Documentos|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.