Dental Tribune United Kingdom Edition No.3, 2017

10 TRENDS & APPLICATIONS Dental Tribune United Kingdom Edition | 3/2017 Apical transportation Microsurgical handling of a procedural error during apical mechanical preparation Prof. Leandro A.P. Pereira, Brazil Endodontics is the dental specialty that is concerned with treating or preventing pulpal pathologies and apical periodontitis. The main ob- jectives of endodontic treatment are to clean and disinfect the entire length of the root canal system up to a healthy level.1 When, through meticulous treatment, such objec- tives are achieved, success rates can exceed 94 per cent.2, 3 In pursuit of such results, during endodontic therapy, mechanical preparation is carried out with endodontic instru- ments and chemical preparation with irrigating solutions. within the dentinal tubules. In ad- dition, it increases the dia m eter and shapes the main canals, facili- tating ﬂ ow of larger volumes of ir- rigating solutions to the apical third.6, 1 It also creates a favourable conical shape for endodontic ﬁ ll- ing. Therefore, it directly inﬂ u- ences the quality of the disinfec- tion process and, consequently, the prognosis of the case. Procedural errors during me- chanical preparation may make it impossible to achieve the re- quired disinfection levels. Yousuf nal wall structure on the outside curve in the apical half of the canal due to the tendency of ﬁ les to re- store themselves to their original linear shape during canal prepara- tion; may lead to ledge formation and possible perforation.” The inadvertent use of rigid endodontic ﬁ les, such as stainless steel, especially of larger diame- ters, without previous examina- tion of the internal dental anat- omy as part of the procedure, in- creases the risk of transportation of the foramen. appropriate bacterial control.12 As a result, they worsen the prognosis of the clinical case involved. According to Gluskin et al., transportation of the foramen can be classiﬁ ed into three categories: • Type I represents a minor move- ment of the physiological posi- tion of the foramen. • Type II represents a moderate movement of the physiological position of the foramen, result- ing in a considerable iatrogenic relocation on the external root surface. In this type, a larger rier to control bleeding and to serve as a physical shield to pre- vent extrusion of the endodontic ﬁ lling material. In these situations, placing an apical cap with mineral trioxide aggregate (MTA), followed by conventional endodontic ﬁ lling, can be considered. However, in clinical cases with apical transpor- tation of Type III, it is generally not possible to achieve cleaning, disin- fection and proper ﬁ lling. Thus, these steps should be performed as well as possible and be followed by an apical microsurgery to remove the untreated apical region. 1 4 2 3 5 6 7 Fig. 1: Initial clinical view of tooth #11. — Fig. 2: Initial clinical view of tooth #13. — Fig. 3: Initial radiograph. — Fig. 4: Tomographic image demonstrating the transportation of the foramen of tooth #11. — Fig. 5: Tomographic image demonstrating the transportation of the foramen of tooth #13. — Fig. 6: Clinical image captured under the operating microscope showing the original canal trajectory and apical deviation of tooth #11. — Fig. 7: Radiograph of an endodontic ﬁ le positioned in the apical deviation of tooth #11. After cleaning and shaping, en- dodontic ﬁ lling must be per- formed to ﬁ ll three-dimensionally and seal the endodontic space in order to prevent bacterial re- contamination, maintaining the sanitation conditions achieved through the previous steps. The mechanical preparation of the root canal system is of utmost im- portance in the process of estab- lishing endodontic saniti sation.4, 5 It is responsible for phy sically re- moving the infected dentine and, located consequently, bacteria et al. evaluated 1,748 endodonti- cally treated teeth using digital ra- diography and found procedural errors in 32.8 per cent (574 teeth) of them. Transportation of the apical foramen, whether leading to root per foration or not, is among the most common errors during en- dodontic treatment, especially in curved canals.7–9 The Glossary of Endodontic Terms by the American Associa- tion of Endodontists deﬁ nes “canal transportation” as “Removal of ca- Insufﬁ cient cleaning of canals, especially the apical third, pre- disposes treatment to endodontic failure.10, 11 Transportation of the foramen may not only impair dis- infection of the canal system by disabling access to its original tra- jectory, but also irritate the peri- apex by extruding bacteria and their by-products and derail the ideal apical adjustment of a gutta- percha cone. These technical hin- drances due to operational error in the preparation phase can nega- tively inﬂ uence apical sealing and communication with the peri- apical space exists. • Type III represents a severe movement of the physiological position of the foramen and the canal, resulting in a signiﬁ cant iatrogenic relocation. Treatment of apical transpor- tation cases can be performed ac- cording to various clinical ap- proaches. Canals with Type I trans- portation can usually be cleaned and ﬁ lled. Type II may be ﬁ lled af- ter the application of an apical bar- Clinical case A 55-year-old female patient (American Society of Anesthesiolo- gists Physical Status Class I) visited the dental ofﬁ ce complaining about spontaneous, constant pain, exacerbated during mastication and apical palpation in the region of teeth #13 and #11, which had been treated endodontically over the course of the last three months. The patient reported that she did not feel pain before the initial en- dodontic treatment began. After 8 9 10 11 Fig. 8: Apical cap with MTA Repair HP. — Fig. 9: Canal drying of tooth #12 with SurgiTip (Ultradent Products). — Fig. 10: Retroﬁ lling of tooth #12 with MTA Repair HP. — Fig. 11: Immediate postoperative radio- graph. — Fig. 12: Control radiograph ﬁ ve months later of the periapical repair.

Dental Tribune United Kingdom Edition No.3, 2017

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