Purpose: To evaluate microleakage of pit and fissure sealant after using four different pit and fissure preparation techniques 1) Pumice prophylaxis and acid etching 2) Fissure enameloplasty and acid etching 3) Self etching adhesive system 4) Air abrasion and acid etching. Methods: Eighty exfoliated primary molars with no clinical evidence of caries were randomly divided into 4 groups of 20 eac...

Pumice fragments recovered from an archeological excavation on the Greek mainland have been correlated by means of index of refraction measurements with the Late Bronze Age volcanic eruption on the island of Thera (Santorini) in the Aegean Sea. Pottery from the strata containing the pumice dates from the 15th century B.C.

However, the best method for cleaning the pits and fissures has not been agreed upon. Taylor and Gwinnett3, Garcia-Godoy and Gwinnett4,5, and GardaGodoy and Medlock6 showed that pumice particles become lodged in the fissures and are not removed after rinsing with a stream of water. Main et al. 7 demonstrated that the acquired pellicle is removed completely by standard acid-etching and Donnan an...

The geometry of mesoscopic single and multiple layer folds in rhyolitic obsidian ̄ows is investigated. Folds are composed of obsidian embedded in a matrix of pumice. Folds form by buckling processes as indicated by discontinuous deformation between obsidian and pumice layers and by the geometries of wavetrains. Buckling occurs through a continuum of styles controlled largely by the thickness ra...

Wastewater treatment of some heavy metals was carried out by synthetic zeolite P1, which was prepared by alkaline hydrothermal treatment of the pumice. Both of the pumice raw materials and synthetic zeolite were investigated for their chemical phase composition, physical properties, and microstructure. The adsorption behavior of Na-zeolite P1 with respect to Co(+2), Cu(+2), Fe(+2), and Cd(+2) h...

Effect of various washing process on the properties of indigo dyed four-way stretch denim fabric was studied in this research. The different washing techniques (Dark washenzymatic treatment, Medium washenzymatic treatment with pumice stone, Bleach washenzymatic treatment with bleaching powder and pumice stone, Acid Wash-Enzymatic treatment with potassium permanganate and pumice stone) were appl...