the most difficult clinical considertions in orthograde root canal treatment are generally related to the anatomy of the teeth. three-canalled maxillary and mandibular premolars (mini-molars) have been reported in several studies. the purpose of this paper was to review various aspects of three-canalled premolars including incidence, clinical and radiographic diagnosis, racial predisposition, a...

Anatomical variations must be considered in clinical and radiographical evaluations during endodontic treatment. Access cavity modifications may be required for stress free entry to complex anatomy. Higher magnification and illumination can be useful for access cavity preparation and to recognize and locate additional canals. This article describes the diagnosis and clinical management of two c...

Crystal structures of the lactose permease of Escherichia coli (LacY) reveal 12, mostly irregular transmembrane α-helices surrounding a large cavity open to the cytoplasm and a tightly sealed periplasmic side (inward-facing conformation) with the sugar-binding site at the apex of the cavity and inaccessible from the periplasm. However, LacY is highly dynamic, and binding of a galactopyranoside ...

Various surgical techniques for the removal of a foreign body from maxillary sinuses have been reported. However, the access window in the lateral wall of the maxillary sinus cavity is not replaced by a bony wall when sinus grafting is not performed. The replaceable bony window provides an access window into the sinus cavity and maintains the integrity of the lateral wall of the sinus cavity af...

AIM The aim of this in vitro study was to assess the microleakage of composite restorations following contamination of access cavity with root canal filling materials of primary teeth. MATERIALS AND METHODS Forty primary canines were selected for this study. Standardized access cavity on the lingual surface of the canine was prepared. The margins of preparation were ended on enamel. The teeth...