BACKGROUND AND AIMS Marginal seal of the material is extremely important in fissure sealant therapy. The aim of this study was to investigate microleakage of flowable composite resins and conventional fissure sealants with or without dentin bonding agent. MATERIALS AND METHODS The occlusal surface of 60 intact extracted human premolars, divided into four groups, were cleaned with pumice/slurr...

Abstract Many species of seabird ingest or are provisioned with pumice stones, buoyant volcanic rocks that thought to aide in digestion, occasionally during times poor prey availability. Unlike other indigestible matter, like plastics, the effect on chick growth, its relationship ingested and variation among years has not yet been examined. We analysed amount from 739 Flesh-footed ( Ardenna car...

This paper summarizes results of a study of porosity, permeability, microstructure and acoustic properties of volcanic and pyroclastic rocks fromCampi Flegrei (CF) andMt. Etna (ET), Italy. We have measured the hydraulic, transport and acoustics properties of 28 room-dry samples at ambient conditions, 25 room-dry samples under confining pressure (up to 60 MPa) and 5 brine saturated samples under...

background dyes are one of the most important industrial pollutants, especially in textile industries. many methods have been proposed in order to remove color from wastewater among which, adsorption is more acceptable due to the ability for its use in the large scale. objectives the objective of this study was to investigate pumice as an inexpensive adsorbent for removal of methylene blue from...

statement of the problem: demineralization of enamel adjacent to orthodontic appliances frequently occurs, commonly due to insufficient oral hygiene. purpose: the aim of this study was to compare two microabrasion techniques on improving the white spot lesions as well as subsequent enamel discoloration. materials and method: sixty extracted premolar teeth without caries and hypoplasia were sele...

damavand is a large dormant stratovolcano in the alborz mountains of northern iran located in one of the most populous provinces, which could be adversely affected by tephra fall from damavand. the youngest known eruption is a lava flow on the western flanks with an age of 7.3 ka. the volcanic products are predominantly porphyritic trachyandesite. three major young pumice deposits, named here a...

to assess the effect of time and temperature (in the pumice mixing phase of olive oil extraction) on the quantity and quality features of the extracted oil, a series of experiments comprised of three levels of mixing time (10, 20, and 30 min), and three levels of mixing temperature (30, 45, and 60°c) were carried out. the recorded data were analyzed in the framework of a randomized complete blo...

PURPOSE To evaluate the shear bond strength of resin luting agent to dentin surfaces cleansed with different agents like pumice, ultrasonic scaler with chlorhexidine gluconate, EDTA and the influence of these cleansing methods on wetting properties of the dentin by Axisymmetric drop Shape Analysis - Contact Diameter technique (ADSA-CD). MATERIALS AND METHODS Forty coronal portions of human th...

Mithraea, religious Roman buildings, are very common in Italian archeological sites. There sixteen Ostia Antica (Rome, Italy)The poor state of conservation, due to the intrinsic environmental conditions, characterized them: they consist open-air museums and caves simultaneously. These places worship by presence heterogeneous materials, such as wall building materials (bricks mortars) others use...