This study proposes a pH-cycling model for verifying the dose-response relationship in fluoride-releasing materials on remineralization in vitro. Sixty bovine enamel blocks were selected for the surface microhardness test (SMH1). Artificial caries lesions were induced and surface microhardness test (SMH2) was performed. Forty-eight specimens were prepared with Z 100, Fluroshield, Vitremer and V...

AIM To analyse the physicochemical properties of a Nano white mineral trioxide aggregate (NWMTA) and compare it with white mineral trioxide aggregate (WMTA). METHODOLOGY White mineral trioxide aggregate and NWMTA were prepared and mixed according to the manufacturer's instructions. Surface area of powder before hydration, setting time, X-ray diffraction and microhardness at pH values of 4.4 a...

The purpose of this study was to test the hypothesis that both human and bovine sclerotic dentin have similar hardness properties, in addition to similar micromorphological characteristics. Sixteen teeth (8 human and 8 bovine) exhibiting exposed dentin in the incisal edge and showing characteristics typical of sclerosis were used. Vickers surface microhardness testing was conducted. Three areas...

This study evaluated the surface microhardness and fluoride release of 5 restorative materials - Ketac-Fil Plus, Vitremer, Fuji II LC, Freedom and Fluorofil - in two storage media: distilled/deionized water and a pH-cycling (pH 4.6). Twelve specimens of each material, were fabricated and the initial surface microhardness (ISM) was determined in a Shimadzu HMV-2000 microhardness tester (static l...

This study observed alteration in the radiopacity and microhardness of expired resin-based materials compared to non-expired materials and the operating characteristics of the X-ray source used. Five 2 mm-thick cured specimens were prepared for each material: composite resins (P60®, Z100®), and a compomer (Dyract AP®). Radiopacity of the specimens was evaluated comparing the density of the resi...

AIM Aim of this study was the evaluation of the microhardness of 4 dental sealants polymerised with two different curing units. METHODS Twenty samples (5 x 5x 2 mm) were prepared with 4 different sealants; 10 samples for each group were polymerised with a plasma curing unit (Apollo 95 E DMD) and 10 with a halogen curing light (Heliolux DLX Vivadent ETS, Schaan, Liechtenstein). For each sectio...

the major problem in material removal process specially grinding is heat generation during the process and thus residual stress on the surface of product. therefore, optimization of high efficiency deep grinding (hedg) process is the main goal of this study in order to reduce heat and residual stress and also increase strength and surface hardness of aisi1045 steel by optimization of the proces...

AIM Short-term and long-term evaluation of the effect of whole human blood or serum contamination on the surface microhardness value and microstructure of white and grey mineral trioxide aggregate (MTA). METHODOLOGY Three groups of 10 samples for each type of MTA were prepared. The first group was mixed with and exposed to fresh whole human blood. The second and third groups were mixed with d...

PURPOSE To evaluate the effects of radiation therapy on deciduous teeth. MATERIALS AND METHODS The enamel and dentin microhardness (n = 12) was evaluated at 3 depths, both before (control) and after each 10 Gy of irradiation and up to a dose of 60 Gy. The morphology was evaluated via scanning electron microscopy (SEM) (n = 8). The data were analyzed using a two-way analysis of variance (ANOVA...