Predicting the anatomical position of the palatal root apex in maxillary first premolars during surgical endodontic treatment.

Introduction: Although many studies have reported on the morphology of maxillary first premolars, to our knowledge, there has never been an investigation reporting the anatomic position of the palatal (P) root tip relative to the B root tip in mesiodistal (MD), buccopalatal (BP), and apicocoronal (AC) dimensions. Such information could help clinicians more accurately locate root apices, reduce surgical morbidity, and improve the precision and prognosis of endodontic periradicular surgery for this tooth.

Methods: Fifty extracted, bifurcated, human maxillary first premolars were individually mounted and photographed under 10x magnification and oriented to simulate a clinical view.

A real-time fluorogenic phospholipase A(2) assay for biochemical and cellular activity measurements.

A fluorogenic analog of the PLA(2) substrate PC, named Dabcyl-BODIPY-PC, or simply DBPC, was synthesized with a fluorescence quencher (Dabcyl, 4-[(4-[N,N-dimethylamino]phenyl)azo]benzoic acid) in the sn-1 acyl chain and a BODIPY fluor in the sn-2 acyl chain. DBPC was recognized by sPLA(2) from each of the four sources examined (bee venom, human synovial fluid, cobra venom, and bovine pancreas). A dramatic and quantifiable fluorescence enhancement of DBPC occurred upon phospholipase digestion both in the presence and absence of excess PC.