This study was done to evaluate the tissue reaction to four different retrograde filling materials. In this study 60 sterile polyethylene tubes (Meditop Corporation (M) SDN. BHD., Malaysia) were divided into 5 groups of 12 tubes each. Subsequently, the first group specimens were loaded with zinc _. free amalgam (Solila Nova, Dentsply), the second group specimens were loaded with Intermediate restorative material (IRM) (L.D. Caulk, Milford, DE), the third group specimens were loaded with Super EBA (Harry J. Bosworth CO, Skokie, IL) and the, fourth group specimens were loaded with Vitrebond (3M. St. Paul, MN, USA). In the last group the tubes were left empty to serve as control. 1 specimen from each group was implanted into the subcutaneous tissue of a single rabbit, making a total of 12 animals each containing an implant of every group. At the end of 2 wks, 4 wks and 12 wks the specimens along with surrounding tissues were removed from 4 rabbits. Subsequently the tissue was fixed in 10% neutral buffered formalin, embedded in paraffin, sectioned, mounted and stained using usual standard technique. The sections were examined and reaction of the soft connective tissue to the material was recorded. The data was analysed statistically.

The objective of this in-vitro study was to evaluate the effects of six in-office agents of desensitization on the hydraulic conductance of human dentin by measuring the mean percentage reduction in permeability over a period of one month. The tested agents were Fluoride varnish (Fluorprotector),resin desensitizer ( Gluma desensitizer ), adhesive resin ( Gluma comfort bond ), laser (Nd: YAG Laser), fluoride iontophoresis (Electric pulp tester, for fluoride iontophoresis) and 3% Potassium oxalate(freshly prepared). Sixty non carious, intact human mandibular third molars were sectioned at mid coronal region and polished to obtain a 1mm thick disc which were divided into six groups. A split chamber device with fluid filtration apparatus was constructed for hydraulic conductance measurements. Permeability of dentin discs was measured at baseline that serves as a control and following the application of the various in-office agents, measurements was recorded post operatively, after 24 hrs, after I week and after 1 month. Mean percentage reduction in permeability was tabulated and statistically analyzed. The results of this study indicate that all the tested agents led to a decrease in dentin permeability Nd: YAG laser gave the highest reduction in permeability throughout the entire period of study followed by Gluma desensitizer Gluma comfort bond, Fluoride iontophoresis, and Fluor protector and 3% Potassium oxalate was the least effective.

The purpose of this paper was to report the possibility for successful endodontic treatment of a complex case of maxillary _. first premolar with three roots and three canals. Radiographic interpretation and correct access cavity preparation were performed. Cleaning and shaping of the root canal followed by cold lateral gutta percha condensation was accomplished. The present report emphasizes the knowledge ofanatomical variations, clinical and radiographic interpretations in maxillary first premolar.