Online ISSN: 2515-8260

Keywords : Bond strength

A comparative evaluation of the effect of various surface treatments on the bond strength of ceramic fused to direct metal laser sintered cobalt chromium alloy- an in-vitro study

Vini Rajeev; Anjana S; Rajeev Arunachalam; Shan Sainudeen; Sivadas Ganapathy; Vaishnavi Vedam

European Journal of Molecular & Clinical Medicine, 2020, Volume 7, Issue 8, Pages 4821-4833

Objective: The purpose of the present study was to compare the influence of various surface treatments on the bonding surface of metal laser sintered Cobalt Chromium alloy cylinder and also to analyse the mode of failure in each category. The objectives were to evaluate and compare the bond strength of ceramic over Direct Metal Laser Sintered Cobalt Chromium alloy disc without surface treatment (Group I) and also with various surface treatments including sandblasting (Group II), acid etching (Group III) and laser ablation (Group IV).
Method: Forty samples of Cobalt Chromium cylinders of dimension 12 ×5 mm were fabricated using direct metal laser sintering. The samples were divided into four groups (N=10) samples each based on the surface treatments. After surface treatment, the samples were veneered with porcelain on the treated bonding surface. The shear bond strength test was done using Instron at crosshead speed 0.5 mm/min. The result were statistically analyzed using one way ANOVA Post hoc test followed by Dunnet t test (p<0.05). The mode of failure was also analyzed using Scanning Electron Microscopy.
Result: The mean bond strength of Group II and Group IV were greater than all other groups. The least bond strength was observed for Group III. The SEM analysis showed a cohesive failure for Group II and IV and mixed failure for Group I and Group II.Conclusion: Laser ablation and sandblasting are effective surface treatments for bonding porcelain to Direct metal laser sintered Co-Cr coping.

Effect of aging in bond strength - A Review

Arumugam Karthick; Bharadwaj B; Dhakshinamoorthy Malarvizhi; Suresh Mitthra

European Journal of Molecular & Clinical Medicine, 2020, Volume 7, Issue 3, Pages 2104-2109

Dental adhesives are used to bond composite resins to tooth structure. The earliest bonding systems required an acid-etch technique and were only compatible with enamel. The challenge has always been to predictably bond to enamel and dentin simultaneously. The material should have such a property that it should have better retention to the dentin and it should be able to withstand forces of occlusion and mastication. The ideal requirements of an effective dentin adhesive system include the ability to thoroughly infiltrate the collagen pathways and partially demineralized zone, to encapsulate the collagen and hydroxyapatite crystallites, to produce a well polymerized durable hybrid layer with high bond strengths. As a hybrid layer is created by a mixture of the dentin organic matrix, residual hydroxyapatite crystallites, resin monomers and solvents, aging may affect each of the individual components differently or may result in synergistic combinations of degradation phenomena within the hybrid layer.