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Purpose: This study investigated the influence of professional mechanical tooth cleaning (PMTC) pastes on the surface texture of different subject materials.Methods: Two one-step PMTC pastes, Clinpro Cleaning Paste for PMTC (CP) and PRG Pro-Care Gel (PG), and multiple-step PMTC pastes, Merssage Regular (MR), Merssagge Fine (MF), and Merssage Plus (MP), were used. For comparison, PMTC was performed using distilled water without paste (DW). The subjected materials used were bovine enamel (ENA) and dentin (DEN), a resin composite (FSU), and lithium disilicate (IEC). The prepared specimens were polished using a #2000-grit silicon carbide paper. PMTC was performed using a brush at 1,000 rpm for 15 s.Results: The surface roughness (Ra) values of the specimens before and after PMTC were measured by laser scanning microscopy. The Knoop hardness number (KHN) of the subjected material was obtained. The types of PMTC pastes and subject materials had a significant influence on the Ra values and KHN. For the majority of subject materials, the descending order of Ra values after PMTC was MR > MF > CP > PG > MP > DW. The descending order of KHN of the materials was IEC > ENA > FSU > DEN.Conclusion: Although one-step PMTC pastes appeared to be effective, it is important to consider the subject material during PMTC. [ABSTRACT FROM AUTHOR]

This study investigated the effect of a coating material containing S-PRG fillers on the demineralization of bovine enamel and dentin, by measuring changes in the transmitted ultrasonic velocity. Bovine enamel and dentin specimens with and without coating (ra=6 for each condition) were cut into blocks, immersed in 0.1 M lactic-acid buffer solution (pH 4.75) for 10 min twice daily throughout the test period, and stored in a demineralising artificial saliva solution (pH 7.0) between treatments. The propagation time of longitudinal ultrasonic waves was measured by a pulser-receiver with a transducer. Data were evaluated using ANOVA followed by Tukey's HSD test (a=0.05). The sonic velocity decreased over time for specimens stored in demineralising solution; however, coated specimens had a significantly higher sonic velocity than those without coating. The coating material containing pre-reacted glass-ionomer fillers therefore appeared to reduce the déminéralisation of enamel and dentin. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the elastic modulus of components at the resin-dentin interface with the use of an ultrasound device. Dentin slabs were obtained from freshly extracted bovine incisors shaped into a rectangular form. After demineralization, the dentin specimens were immersed in adhesives and polymerized. Adhesives were also polymerized and trimmed into the same shape as the dentin slabs. The specimens were then immersed in distilled water at 37°C for up to one year. The ultrasound equipment employed in this study was a Pulser-Receiver, transducers and an oscilloscope. By measuring the longitudinal and shear wave sound velocities, the elastic modulus was determined. When the elastic modulus of adhesive resin-infiltrated demineralized dentin was compared with that of adhesives, slightly but significantly lower values were found for adhesives used in a self-etching primer system. On the other hand, a higher elastic modulus was observed for resin-infiltrated dentin than for an adhesive used in an etch and rinse system. The elastic modulus of the resin-infiltrated dentin prepared with the etch and rinse system was affected by long-term storage in distilled water. [ABSTRACT FROM AUTHOR]