An in vitro study was undertaken to compare the influence of two root canal sealers on the pH of the surrounding periapical medium. The teeth were divided into 3 groups of 25 teeth each. Group 1 & II consisted of root-canals obturated with laterally condensed gutta-percha with zinc oxide and sealapex (calcium hydroxide based sealant) respectively. In group III, root-canals were prepared, but not obturated. An additional group of normal saline was used to monitor the pH changes in other groups. Group III and IV both served as controls. Digital-pH-meter was used to measure the pH of different groups at 1 hr, 4 hr, 1 day, 2 days, 4 days and 7 days after immersion of the specimens. The mean pH was found out for all four groups and statistical analysis was carried out using 'T test. Sealapex was found to significantly raise the pH of the surrounding medium (7.00 to 10.47-10.55) compared to zinc oxide eugenol sealer (7.00-7.77-7.85)

Sealing ability of two root canal sealers zinc oxide engenol and Endometha sone(Septodont) was tested in vitro by dye penetration and SEM study and was compared with a control group where no sealer was used. In all the three groups, gutta percha filling by lateral condensation method was given. It was found that the mean dye penetration at one day was maximum in the control group (10.87 mm) and lowest in zinc oxide-eugenol group (3-72 mm) while Endomethasone had values in between these (4.47 mm). However, after ageing for 7 days no appriciable difference between the two experiment group was seen. On SEM examination, zinc oxide engenol showed good adaptation to canal walls compared to Endomethasone. The control group exhibited distinct voids at filler-tooth interface.

A comparison is made of the toxicity of various zinc-oxide based root- canal sealers. Conventional zinc-oxide eugenol is compared with a sealer containing paraformaldehyde and a sealer containing iodoform. The materials in the unset state were injected subcutaneously in albino rats at predetermined earmarked areas. The experiment showed the maximum toxicity with the sealer containing paraformaldehyde, lesser for zinc-oxide eugenol followed by sealer containing iodoform. Out of the three time intervals, the maximum inflammatory response was at the 7 day study period. The results showed that paraforaldehyde containing sealer is strongly toxic compared to the toxicity of eugenol sealer and that of sealer containing iodoform is the least toxic.

Cases of hyperemic pulps, diagnosed from clinical symptoms were treated by pulpotomy in thirty three adult teeth and were followed up at regular intervals; maximum period of follow41p being 9 years. It was found that only 4 failures could be attributed to the status of the remaining pulp, i.e. failure of the pulpotomy procedure perse. Of these, two failure cases were found at the end of 7 years, both cases being symptom free, when diagnosed. One developed internal resorption in the furcation area and the other developed a peri-apical lesion at the distal root apex of a mandibular molar. The rationale of pulpotomy procedure, the technic, criteria for case selection, prognosis, possible sequelae and their prevention is discussed in detail. An attempt is made to negate many of the old beliefs and a case is made favouring vital pulp therapy in the light of results of the present study and review of relevant literature.

The antibacterial effect of calcium hydroxide paste in distilled water as an intra-canal medicament was studied in twelve cases. It was found that 54.5% of the cases became asymptomatic and sterile in 4 visits, 27.2% in 7 visits, while 18.20% were failures. It is concluded that calcium hydroxide can be successfully used as an intra-canal medicament in highly infected canals.