Influences of novel bonding approaches on demineralized dentin substrate / By Asmaa Ali Mohamed Yassen ; supervisors Enas Mohamed Mohy El-Din, Heba Salah El-Din Hamza.

Supervisors: Enas Mohamed Mohy El-Din, Heba Salah El-Din Hamza.

Thesis (Ph. D.)Cairo University, Faculty of Oral and Dental Medicine, Department of Operative Dentistry, 2007.

Includes bibliographical references (pages 153-164)

This investigation was conducted to study the effect of some different novel bonding approaches on the demineralized dentin substrate. The dentin was demineralized using a specially prepared solution to obtain a natural like carious lesion. A total of 160 freshly extracted sound human molars were selected and used in this study , teeth were unequally divided into three groups according to the test used either microleakage testing , chemical analysis or scanning electron microscopic examination . Each group was further subdivided into two equal subgroups according to the bonding system used either total etching or self etching bonding system. Each subgroup was further subdivided into four equal classes according to the pretreatment material used either the bonding system as described by the manufacture without additional pretreatment (control), deproteinization with sodium hypochlorite NaOCL followed by ascorbic acid as a reducing agent , the use of Copper chloride or Zinc Zeolite . For the microleakage testing, standardized class V cavities were

prepared on the buccal surface of the selected molars. Cavities were then demineralized and treated with the corresponding type of treatment and then restored using resin composite. Restored teeth were warped, immersed in the dye for 2 hours and then sectioned. Microleakage assessment was done by two methods. The first was the dye penetration using the scoring system (0-3) and the second was measuring the gap area in µm2 at the tooth restoration interface by image analysis. Chemical analysis was done by cutting dentin specimens 3 x 2 x 1mm in dimension from the mesial and distal side of the selected molars. Specimens were demineralized by the demineralizing solution and then treated with the corresponding type of treatment. Treated demineralized dentine specimens were totally crushed and added to potassium bromide KBR powder to obtain a final concentration of 1.5% Discs were formed from the prepared mixture and then subjected to Fourier transform infrared spectroscopy (FTIR). Spectra obtained from the FTIR were analyzed and studied to know the chemistry of the formed interface.

Text in English; abstracts in English and Arabic