fluoride-release versus non fluoride-release bonding agents

The purpose of this investigation was to compare the shear bond strength of a fluoride-release, one-component system, bonding agent [Syntac Sprint] with that of a non fluoride-release, one component [Exite] and two-component system [Scotch Bond Multi-Purpose] bonding agents. One hundred and twenty caries free unrestored human teeth were selected for the study. The teeth were mounted in an acrylic resin holder with the buccal surface up. Wet grinding was performed until flat enamel or superficial dentine area of at least 4 mm in diameter was exposed. Each bonding agent was applied to the exposed enamel according to the manufacturer's instructions or to the dentine under three different conditions [according to the manufacturer's instructions, in two successive layers and without dentine conditioning]. Immediately, after application and curing of the bonding agents, the composite part of the specimen [Tetric Ceram HP]was build up. The specimens were loaded to fracture in Lloyed Universal Testing Machine. Mean shear bond strength was calculated for each bonding condition. The data were analyzed and compared using ANOVA and LSD statistical test. After debonding, the specimens were examined using stereomicroscope and scanning electron microscope. The results showed that mean shear bond strength of Syntac Sprint to enamel and dentin were adequate to counteract the reported polymerization shrinkage of composite resin. Application of any of the three bonding agents to dentin in two successive layers has no significant effect on increasing bond strength. All adhesives showed adhesive and mixed adhesive mode of failure in all conditions except in non conditioning dentin condition

Effect of degree of conversion on the mechanical properties of different shades of composite resin restorative materials

The purpose of this investigation was to study the effect of the degree of conversion [DC] on the diametral tensile strength [DTS] and Vickers hardness [VH] of different shades [A[1], A[2] and A[4]] of Heliomolar [Microfilled] and Tetric Ceram [microhybrid] composite resin restorative materials. For each shade of composite, three experimental tests [DC, DTS and VH] were performed. The DC [%] was measured for the uncured and cured six shades of both types of composite using Fourier Transformation Infrared Spectroscopy. For DTS testing, disk-shaped specimens were prepared for each shade. The specimens were loaded to fracture in a Universal Testing Machine. Similar disk-shaped specimens were prepared to measure the composite's surface hardness using Vickers Micro-hardness Tester. The mean values of DC [%], DTS [MPa] and VH [kg/mm[2]] were calculated. The results were analyzed and compared using ANOVA and Least Significance Difference statistical tests. In addition, the interrelationship between DC, DTS and VH was investigated. The results showed that shade Al in both Heliomolar and Tetric Ceram showed the highest values of the DC, DTS and VH. On the other hand, shade A4 in both types exhibited the lowest values. There was a high positive correlation between all the studied parameters in both Heliomolar and Tetric Ceram composite resin

Correlation between alveolar bone resorption and soft tissue relapse after two different mandibular vestibuloplasty techniques

Eleven edentulous patients were participated in the present study. Patients were randomly divided into two groups for m and ibular vestibuloplasty. The first group was treated by Godwen's technique and the second group was treated by Edlan's technique. Clinically, it was found that there was a highly significant correlation between alveolar bone resorption and sulcus relapse postoperatively, while there was no significant difference between the two groups by cephalometric evaluation. These results indicated that the alveoloplastic operation for deepening sulcus had no significant effects on bone resorption

local delivery of antibiotic and anticancer agents from cold cure acrylic strips [In-vitro study]

Local drug delivery release relatively high doses of the drug to the lesion with minimum side effect. In this paper a new device of acrylic strip is used to study the release of both anticancer drug [Zonasar] and different types of antibiotics in the serum and rat tissues. It was found that all the studied antibiotics and the anticancer drug reached the tissues and the serum 48 hours after implantation of the strips in the rat tissue. This may suggest that the acrylic strip can be utilized as a device to release chemotherapeutic agents directly into the lesions, which may minimize the systemic complications of chemotherapeutic agents and increase its effectiveness