Dental Tribune United Kindom Edition

July 18-24, 201116 Endo Tribune United Kingdom Edition E ndodontics is all about pre- serving the natural denti- tion. There is no better im- plant than the natural tooth, given the fact that it can be treated and restored effectively and predict- ably. Many factors, such as root perforation, affect the prognosis of endodontic treatment.1 Today, per- forations can be managed predict- ably with the use of MTA cement as sealing material.2 The purpose of this article is to illustrate the endodontic retreat- ment of a mandibular first molar with perforation in the coronal third of the mesiolingual root ca- nal, aided by the use of magnifica- tion provided by the dental operat- ing microscope (OM). Case report A 61-year-old male patient, with a non-contributory medical history, was referred by a general dentist for retreatment of a mandibular first molar. The tooth was tender to percussion. Peri-apical radiolu- cency was evident in both roots and the furcation area. A previous root canal treat- ment had been performed more than ten years ago. The canal filling was short in length and the remains of a screw post were present in the mesiolingual canal (Figs 1 & 2). The treatment plan was to restore the tooth with a cast dowel and porcelain-fused-to- metal (PFM) crown. After local anaesthesia had been administered, a rubber dam was placed and the temporary filling removed. The fragmented post was removed by means of ul- trasonic tips under magnification (G6, Global Surgical). Owing to the vicinity of the post to the furca- tion, care was taken not to remove dentine distal to the post. The root- filling material apical of the post and from the orifices of the other root canals was also removed with ultrasonic tips. Observation under high magnification revealed a small perforation of the root-canal wall where the post was placed (Fig 3). The patient and the refer- ring dentist were informed that the tooth was to be retreated and the perforation defect sealed with MTA cement (DENTSPLY Maillefer). A copious amount of irrigation (2.5 per cent NaClO) was used throughoutthetreatment.Theroot canals were flared with a combi- nation of Gates-Glidden burs and rotary NiTi instruments. Under high magnification, an additional root-canal space was found in the distal root (Fig 4). Remnants of the previous root-canal fill- ing material were removed with a combination of hand files and rotary instruments, and patency was achieved with small stainless- steel hand files. Working length was calculated with an apex loca- tor (Root ZX mini, J. Morita) and PathFile (DENTSPLY Maillefer) rotary instruments were used for pre-flaring. The mesial root canals were instrumented to 40/.04 and the distal to 50/.04 with rotary instru- ments (BioRace, FKG). The smear layer was removed through one- minute irrigation with 17per cent EDTA (Ultradent). Passive ultra- sonic irrigation was performed with 2.5per cent NaClO and ESI needles (EMS), three times for one minute each in every ca- nal. The canals were dried and Ca(OH)2 was placed with a Len- tulo spiral (DENTSPLY Maillefer) as an intra-canal medicament. Cavit G (3M ESPE) was used as temporary filling material. The patient was given oral and written post-operative instructions and was told to return after 15 days. At the second appointment, the anti-microbial irrigation regimen was repeated and the canals were dried with sterile paper points. Gutta-percha points were placed in the canals and a master-cone radiograph was taken (Fig. 5). The sealer used was AH Plus (DENT- SPLY DeTrey). The continuous wave of condensation technique was applied during obturation with System B (SybronEndo) at 4mm from the apical terminus of the canal, and back-filling was done with thermo-plasticised gutta-percha using the Obtura III Max (Obtura Spartan). Care was taken not to accidentally push sealer into the perforation site. The mesiolingual root canal was back-filled to a level apical of the perforation (Fig 6). After obtura- tion, white MTA, delivered with the MTA gun (both DENTSPLY Maillefer), was used to seal the perforation site. As requested by the referring dentist, no post space was left in the distal root canal, as he wished to create his own space to place an intra-radicular post (Fig 7). Cavit-G was used as tem- porary filling material. The patient was referred back to the dentist for the final restoration and was told to return after a six-month period for a recall examination. At the recall appointment sev- en months later, the radiograph showed no evident radiolucency in the peri-radicular tissues of the tooth (Fig 8). However, it also revealed that the new post had not been placed at the adequate length. The general dentist was contacted and reassured me that a new dowel and PFM crown would be placed. Conclusion Advances in technology and bio- materials have not yet been proven to enhance overall success rates in endodontics.3 Root perforations can affect prognosis in a negative way.1 Nevertheless, the OM al- lows clinicians to work with great precision even under the most demanding circumstances,4 and MTA greatly enhances success when treating perforations in the furcal area.2 In addition, the use of ultrasonics under magnifica- tion facilitated the removal of the post despite its small size. Passive ultrasonic irrigation removed de- bris and necrotic tissue effectively from the mesial isthmus area, al- lowing obturation material to fill it, as can be observed in the final X-ray (Fig 8). DT Editorial note: A complete list of references is available from the publisher. Retreatment of a lower molar Dr Konstantinos Kalogeropoulos presents a retreatment case About the author Dr Konstantinos Kalogeropoulos is a postgraduate En- dodontics resident at the University of Athens Dental School. He has pub- lished in national and international scientific journals and presented a large number of oral presentations and posters at endodontic congresses. info@athensendo.gr www.athensendo.gr Dr Konstantinos Kalogeropoulos 73–75 Deinokratous Str. 11521 Kolonaki Athens Greece Fig 1 Fig 2 Fig 3 Fig 4 Fig 5 Fig 5 Fig 7 Fig 6 ‘There is no better implant than the natural tooth, given the fact that it can be treated and restored effectively and predictably’ Fig 8