Bonding Effectiveness Study of the Universal Adhesive on Caries-Affected Dentin of Deciduous Teeth

Abstract

Aim: The aim of this study was to investigate the bonding effectiveness of the universal adhesive on caries-affected dentin and normal dentin of deciduous teeth.

Methods Extracted twelve second deciduous molars with one adjacent surface carious were collected. The half teeth with caries adjacent surface were grouped into the caries-affected group (Group test), while the caries-free half were grouped into the control group (Group control). For the Group test, carious tissue was removed with slow speed ball drill under the indication of caries maker.For the Group control, at the other side of the occlusal surface sound dentin was prepared to the similar deep level. Single bond Universal adhesive system using self-etch strategies was applied following the manufacturer's instructions.The defective part was filled with Shofu Beautifil II Namer, a commonly used resin composite in pediatric dentistry. Vertical sticks were obtained and subjected to tensile stress test. The morphology of the bonding surfaces were observed by scanning electron microscope and transmission electron microscopy.

Results: Electron microscope observation showed that there was no significant difference in morphology between caries-affected dentin and normal dentin. The minerals and smear layer were removed after acid etching, and the collagen network of dentin tubules and inter tubular dentin was exposed. There was no significant difference in the micro-tensile strengths between Group test and Group control (P > 0.05). Conclusion In vitro, caries-affected deciduous tooth dentin could achieve similar bonding strength to normal tooth dentin when Single Bond Universal adhesive was applied.