ROEN0310

40 I I case report _ retreatment In the above case, the restoration was removed and the operating microscope was used to identify the mesial canals. Methylene blue was used to stain the tooth to check for and assess cracks. The silver points were removed by bypassing them with small files using solvent to dissolve the surrounding sealer and braiding three size 15 files around each point to remove each one intact. The remaining paste and obturation material apically was bypassed and pa- tency was achieved as demonstrated by obtaining a consistent reading on the apex locator. As the mesial canals had a double curvature, a serial step-back approach was initiated with NiTi rotary files in order to minimise the stress on the in- struments.Patencywasachievedandthecanalswere dressed with calcium hydroxide for a week. Atasubsequentvisit,nosymptomswererecorded and the canals were irrigated with sodium hypochlo- rite and EDTA to remove any remaining calcium hy- droxide and any organic and inorganic debris. The canalswerethenobturatedwithawarmverticalcon- densationtechniqueusingSystemBandObtura(both SybronEndo). There was some extrusion of sealer, which does not affect the outcome of treatment but may delay healing (Fig. 2). _Conclusion It is well established that it takes time for a lesion ofendodonticorigintoheal.Weexpect25percentof lesionstohealcompletelyaftersixmonthsand50per centtoreturntohealthafteroneyear.Outcomestud- iessuggest74to86percentoflesionswillcompletely heal after initial treatment or orthograde retreat- ment.4 These high retreatment success rates may surprise many practitioners; however, an even more impressive91to97percentwillbeasymptomaticand functional over time. Modern advances, such as the operating micro- scope,NiTiinstrumentation,ultrasonicirrigationand thermoplastic obturation techniques, are combined with the traditional use of rubber dam and chemical debridement using sodium hypochlorite and calcium hydroxide to obtain these outstanding success rates (Figs. 1 & 3). Success in root-canal retreatment depends on preventingcontaminationofthecanalsduringtreat- ment and disrupting the bacterial biofilm to create conditions conducive to healing. The patient was advised to return to his general dental practitioner immediately following treatment for placement of a cuspal coverage restoration. The importance of this wasagainemphasisedfollowingthereviewappoint- ment. There is evidence that posterior teeth not crowned following endodontic treatment are six times more likely to be lost. Thus, root-canal retreat- ment is a predictable treatment strategy that may enable patients to retain their natural teeth for an extended period of time._ Editorial note: A list of references is available from the publisher. Fig. 2_Post-op radiograph with temporary restoration. Fig. 3_Post-op radiograph at six months. roots3_2010 Dr Daniel Flynn qualified from the Dublin Dental School and Hospital,Trinity College (Ireland),in 2002. Dr Flynn recently joined the EndoCare team headed by Dr Michael Sultan.He has lectured in both the UK and Ireland and provides hands- on courses for general practitioners.He also teaches Endodontics at the Eastman Dental Institute for Oral Health Care Sciences.For more information please contact EndoCare at reception@endocare.co.uk or visit www.endocare.co.uk. _about the author roots Fig. 3 Fig. 2