BACKGROUND A prolonged life of fissure sealant has always been the target for preventing caries in vulnerable newly erupted teeth. The use of preparatory techniques including bur introduction to the fissures is considered among such improving steps. MATERIALS AND METHODS Ninety freshly extracted healthy maxillary premolar teeth were randomly selected for this investigation. Teeth were then di...

OBJECTIVES CO(2), Er:YAG and Nd:YAG lasers have been used in endodontic surgery. This in vitro study evaluated 1% Rhodamine B dye penetration using computer-assisted morphometry (ImageTool Software) of 108 endodontically treated human permanent canines. MATERIAL AND METHODS Teeth were divided into 9 groups according to the technique used: A: 90-degree apicoectomy with bur, root-end cavity pre...

Bur oak (Quercus macrocarpa Michx.) and chinquapin oak (Q. muehlenbergii Engl.) leaves were exposed to high temperatures at various photosynthetic photon flux densities under laboratory conditions to determine if species-specific responses to these factors were consistent with the distribution of these oaks in gallery forests in the tallgrass prairies of northeastern Kansas, USA. Measurements o...

Roughness increases significantly after finishing procedures. The aim of this study was to assess by the atomic force microscope (AFM) the effect of finishing instruments on the surface roughness of composite resins. A nanofiller composite resin (Filtek Supreme, 3M-F) and a microhybrid composite resin (Point 4, Kerr-P) were selected. The finishing procedures were done with a 30-blade carbide bu...

Objective: The aim of this study was to compare the number of crack formation in retrograde cavities after preparation with ultrasound, Er,Cr:YSGG (erbium, chromium:yttrium, scandium, gallium and garnet) laser with different power and frequency settings and bur. Materials and methods: Root canals of 60 extracted human maxillary incisors were prepared, the apices were horizontally cut and class ...

BACKGROUND The present study aimed at 3D analysis of adhesive remnants and enamel loss following the debonding of orthodontic molar tubes and orthodontic clean-up to assess the effectiveness and safety of One-Step Finisher and Polisher and Adhesive Residue Remover in comparison to tungsten carbide bur. MATERIALS AND METHODS Thirty human molars were bonded with chemical-cure orthodontic adhesi...

This study compared the microtensile bond strength (MTBS) of three all-in-one adhesive systems and a two-step system using two types of burs to prepare the dentin surfaces. Flat coronal surfaces of 24 extracted human molars were produced using either regular-grit or superfine-grit diamond burs. Resin composite was then bonded to equal numbers of these surfaces using one of the four adhesives: C...

The aim of this study is to examine the effect of different finishing and polishing systems on the surface roughness, microhardness and microleakage of a nano-hybrid composite. The effect of four different finishing and polishing systems (Mylar-strip, Diamond finishing bur, Sof-lex disc, PoGo) were evaluated on a nanohybrid composite (Ceram-X mono, Denstply). The surface roughness was measured ...

Friedel-Crafts alkylation of 4-tert-butylaniline with 2 equiv of benzhydrol affords bulky 2,6-bis(diphenylmethyl)-4-tert-butylaniline (Ar*NH2) in good yield, which can be readily synthesized on a tens of grams scale. The reaction of 6 equiv of Ar*NH2 with triphosgene generates the symmetric urea (Ar*NH)2CO, which, upon dehydration with a P2O5/Al2O3 slurry in pyridine, produces the sterically en...