Twenty five extracted human anterior teeth having straight roots were used in this study. The teeth were subjected to standard bio-mechanical iostrumen- tation and finally irrigated with high volumes of different irrigating solutions, with normal saline as control. After the experimental procedure, the roots were split and examined under a scanning electron microscope. The results were based on both photomicrographs and statistical analysis. It was found that 10 ml of 15% EDTA followed by 10 ml of 5% NaOCl was the most effective debridement regimen.

Resistance of endodontically treated teeth to fracture was determined by application of a compressive force, with the help of Instron testing machine. 72 freshly extracted maxillary central incisors were selected. Root canal treatment was done in 64 teeth, which served as experimental group. Eight untreated teeth served as control. 40 experimental teeth were reinforced with posts and 24 were left without posts. The different methods of reinforcement of the endodontically treated teeth were evaluated, and it was found that teeth reinforced with post offered maximum resistance to fracture.

The present paper attempts to study the role of calcium hydroxide in different endodontic situations. It is used in immature teeth with peri-apical infections, large peri-apical lesions including apical cysts (radiographic interpretation) and in resistant infections. The method of use of calcium hydroxide along with treatment regime and importance of careful execution of each phase of endodontic treatment is described. In addition, the relevant literature is reviewed in an attempt to understand the mechanisms of action of calcium hydroxide. Initial response to calcium hydroxide treatment was found to be very encouraging clinically. The pus discharge stopped, intra oral sinuses healed and pain and swelling reduced. Radiographically the radioluscency decreased in size with bone filling in from the periphery. However, long-term follow-up of the treated cases is required to assess the healing potential and success rate, achievable by this mode of treatment.

Root canals of freshly extracted single rooted teeth were prepared using hand and ultrasonic instrumentation. The comparative evaluation of efficacy of these two techniques was done using Scanning Electron Microscope (SEM). No significant difference was observed in the cleaning ability of the two techniques when used separately. However, hand instrumentation when used together with ultrasonic instrumentation gave better results.

The antibacterial effect of 5% NaOCl and, 15% EDTA, singly and in combination with normal saline as control was studied in 20 maxillary central incisors. Each tooth was treated at five appointments and the bacteria present in the root canals were studied at each appointment. It was observed that 5% NaOCl, combination of 5% NaOCl and 15% EDTA and normal saline were all 80% effective (4 out of 5 cases in each group became sterile) in reduction of bacterial colonies from the root canals. However, considering the economy, easy availability and relative safety of normal saline, it alone can be a suitable irrigating solution for achieving considerable reduction in bacteria from root canals.

Single sitting root canal treatment can he an answer in many endodontic cases provided the cases are properly selected and the technique is carried out with clear understanding of the basic concepts of different phases of endodontic treatment. In this article, various indications and contra indications of single visit root-canal therapy with step-by step procedure for its execution is described. Single sitting root canal treatment compared to multi-visit treatment has shown no difference in either the success rate or post-operative complications and there is a resurgence of interest in this mode of treatment in recent times.