COMPARATIVE IN-VITRO INVESTIGATION OF DIFFERENT METHODS FOR TEMPORARYROOT-CANAL FILLING WITH AQUEOUS SUSPENSIONS OF CALCIUM HYDROXIDE

Three methods for temporarily filling root canals with calcium hydroxi de pastes were compared. Each of 20 root canals of extracted, human, s ingle-rooted teeth was shaped with hand instruments under standardized conditions up to ISO size 50 and filled using a syringe system, a len tulo spiral or an endodontic reamer. Quality of fillings was assessed radiographically and by inspecting ground preparations. Ridit (relativ e to an identified distribution) analysis was employed to confirm diff erences in frequencies of certain quality criteria obtained with vario us application methods. With regard to degree of obturation and occurr ence of porosities, application of temporary fillings with a lentulo s piral or syringe system revealed significantly better results than app lication with hand instruments (reamer). No differences with regard to degree of obturation were detected when comparing results obtained wi th syringe or lentulo. Fewer porosities in the apical part of the root canal were seen, both on radiographs and ground sections, with the sy ringe system compared with the lentulo spiral. In the presence of some contradictory reports found in the literature, the present study sugg ests that, after straight or slightly curved root canals have been sha ped up to at least ISO size 50, high quality temporary root canal fill ings may be obtained by application of an aqueous suspension of calciu m hydroxide with a syringe system.