Application Of Conventional Instruments For Difficult Root Canal Therapy In Clinical Practice

Background: In clinical root canal treatment, difficult root canal is the mostdifficult problem we often encounter. Difficult root canal mainly includes multiple rootcanals, calcified root canal, curved root canals, C-type root canal and intracanal foreignmatter. Currently, such difficult root canal can be treated perfectly only in somecolleges or large dental hospitals with the equipment of root canal microscope,ultrasonic files, mechanical nickel-titanium system and warmfilling system.Therefore,the exploration to the effective negotiatation methods for difficult root canal using theconventional instruments will help to improve the success rate of difficult root canaltreatment in general hospitals or primary hospitals.Root canal preparation is the most critical step in root canal treatment, root canalpreparation is to clear the residual pulp tissue debris and infected dentin in the rootcanal through machinery preparation as well as chemical drugs washing, clean andshape the root canals, and ultimately achieve the purpose of easy filling and closure ofthe root canals. The basic requirement is to expand the root canal while maintaining theoriginal shape of the root canal system. Due to the complexity of difficult root canal,Negotiating and expanding the root canal is undoubtedly a main difficulty in root canaltreatment.Objective: To observe the preparation of difficult root canal by conventionalinstruments such as hand Protaper file combined with G drill, K file as well as C+file,and to explore the technologies and methods for difficult root canal treatment and toprovide theory and practice basis for the clinical application in primary hospitals.Methods:10clinical cases were collected. Inclusive criteria:①Teeth restorationis feasible;②No restriction of jaw opening, cooperate with treatment;③Withoutsystemic disease;④Informed consent. Exclusive criteria:①Residual root is2mmbeneath the gingival;②Severe progressing periodontal disease or severe root furcation lesion;③Easy root canal;④The patient do not accept to the root canal therapy.Removed all dental detritus, opened the pulp chamber and fully exposed the pulp cavityunder direct vision, carefully observed and looked for the root canal orifices, used handProTaper file system combined with regular instruments such as C+file and adoptedcrown-down technique to prepare the root canal. If there was calcification obstruction inroot canal orifice, we used long-handled ball diamond drilled and grinded downwardalong the calcification obstruction point, until the DG16could be probed into the canal.Firstly we negotiated with10#C+file to the apical stop, stopped in case of resistance,used SX to do crown extension in root canal to open the root canal orifices until10#C+file was able to touch the apical stop. We did the preliminary cleaning of root canalwith15#C+file, then performed crown third of root canal preparation with S1andmiddle third root canal preparation with S1, and the root apical preparation with F1toF3, lubricated the canals using EDTA gel in the whole preparatory process. In case ofsevere apical curvature, used pre-curved C+file for root canal check, alternately useS1or SX and S2for straight path in the canal. Flushed the root canals with1%NaOCLand saline alternately every time when we replaced the equipment. When the root canalpreparation was completed, rinsed the root canal with a mount of distilled water, driedthe root canal with paper tip, measured and recorded the length of root canals, thencompleted the one-time filling with the French Cortisomol sealer and taper04－06gutta-percha by lateral and vertical condensation techniques. Recorded the details in theprocess of root canal negotiation, preparation and the filling effect in the course oftreatment, as well as the intraoperative and postoperative reactions of the patients.Results:10cases with root canals negotiation were successul and there were nocomplications such as canal transportation, root tip obstruction, steps or broken needles,root canal filled perfectly with continuous taper shape.Conclusions: Perfect root canal therapy could be achieved by conventionalinstruments in difficult root canal, avoiding complications at the same time. Theoperator was able to achieve a good therapeutic effect when they were with patient,carefulness and a wealth of experience, referred from the X-ray from different angles,and used conventional instruments such as hand Protaper file system combined with Gdrill, K file and C+file, with the application of effective drug reagents.