The effect of Chloroform, Xylene and Halothane on Enamel and Dentin microhardness of human teeth was studied in this in-vitro study. A total of 60 specimens — 30 specimens on Enamel and 30 specimens on Dentin were studied. Equal number of teeth were treated with Xylene, Chloroform, Halothane and with 0.3% Phosphoric acid as positive control and Saline as the negative control. A Vicker’s microhardness test was carried out on the specimens. A significant decrease in Enamel and Dentin microhardness was found in all the solvent treated groups. The amount of decrease in microhardness was directly related to the exposure time.

A study was conducted to compare the effect of calcium hydroxide paste mixed with water and/or glycerine and used as an intracanal dressing on the sealing ability of two different root canal sealers. It was found that when calcium hydroxide is used as an intracanal dressing, it has to be removed completely, when sealer other than calcium hydroxide based is used for obturation. But with calcium hydroxide based sealer, better apical seal is obtained when calcium hydroxide is used as an intra-canal dressing.

The failure to locate additional root canals and extra roots are important causes for failure of endodontic treatment. Although the root anatomy is highly complex and unpredictable, the knowledge of the normal and its frequent variations can greatly enhance the success rate in endodontic practice. Majority of the maxillary second premolars have a single root with one or two root canals. Occasionally two roots and two canals may be present. Maxillary second bicuspid with three roots is an extremely rare variant. In the case presented here, three root canals were located and three separate roots identified and managed endodontically in a maxillary second premolar. Peri radicular surgery was performed and apicectomy done in all three roots.

The purpose of this in-vitro study was to assess the sealability of different commonly used restorative materials in pulp chamber of multirooted teeth. Sixty freshly extracted molars were endodontically treated and their pulp chamber and coronal access were restored with (1) zinc oxide eugenol and gutta percha, (2) silver amalgam, (3) glass ionomer, (4) silver amalgam over base of glass ionomer and (5) silver amalgam over base of zinc oxide eugenol and gutta percha restorations in 10 teeth each. All the samples were evaluated for microleakage using 2% methelene blue dye.The amalgam group showed significantly less leakage than all the other groups except amalgam over glass ionomer base, while gutta percha zinc oxide eugenol intermediate restoration demonstrated significantly greater leakage than other materials (p<.05). Glass ionomer cement exhibited inferior sealability than other permanent pulpal restorations while base of glass ionomer cement depicted better coronal seal than the zinc oxide eugenol gutta purcha base under amalgam restoration (p<.05).

Perforation of the root canal system is the second largest cause of root canal failure. Failure to seal the perforation defect permits rapid break- down of the periodontium and eventual loss of tooth. Hence sealing the defect is of paramount importance. Although root perforations may be repaired surgically, furcation perforations are usually inaccessible by surgical approach, especially if the defect is situated lingually, in a mandibular molar. Moreover, surgical procedure will often lead to loss of attachment, chronic pocket formation, and peri-odontal furcation involvement. Perforations have been treated using a non-surgical intracoronal procedure of placement of a repair material into the defect. Amalgam and lightcured Glass ionomer cement are the most commonly used repair materials though both of them show extrusion into the furcation area. An in vitro study was carried out to evaluate the ability of calcium sulphate barrier to control the extrusion of repair material into the furcation area and to study the effect of these barriers on sealing ability of repair material. It was found that calcium sulphate provided a successful barrier against over extension of repair material, though the sealing ability of amalgam and Glass ionomer cement was significantly reduced by it. Glass ionomer cement over calcium sulphate was considered a better combination if the amount of extrusion and sealing ability of the materials are considered.

Two cases of large periapical lesions are presented.The lesions were treated by conservative endodontic therapy, following which the lesions showed complete resolution. These results suggest that the largeness of a lesion does not mandate its surgical removal and that even cyst-like lesions heal following conservative therapy.