QUINTESSENCE INTERNATIONAL

Endoscopic treatment Joshua Moshonov, DMD1/Eli Michaeli, DMD2/Oded Nahlieli, DMD3

Objective: To describe an innovative endoscopic technique for . Materials and Methods: Root canal treatment was performed on 12 patients (15 teeth), using a newly developed endoscope (Sialotechnology), which combines an endoscope, irrigation, and a surgical microinstrument channel. Results: Endoscopic root canal treat- ment of all 15 teeth was successful with complete resolution of all symptoms (6-month follow-up). Conclusion: The novel endoscope used in this study accurately identified all microstructures and simplified root canal treatment. The endoscope may be considered for use not only for preoperative observation and diagnosis but also for active endodontic treatment. (Quintessence Int 2009;40:739–744)

Key words: endoscope, root canal treatment

New materials, techniques, and instruments Recently, the dental operating microscope are being introduced to the marketplace to has been implemented to enhance visibility assist clinicians in providing patients with during dental procedures.1,2 The operating more predictable and reliable endodontic field has reached a magnification of up to treatment. Since the establishment of micro- 20×, facilitating treatment procedures. surgical principles in the 1990s, the field of However, the microscope, a sizable tool, has made continuous and sub- remains between the operating field and stantial progress. Root canal preparation has practitioner, complicating the clinician’s abili- been simplified and optimized with the aid of ty to work. Other disadvantages are the inter- newly developed nickel titanium root canal ference of hands and the handpiece with the preparation instruments and new methods of visualization of the surgical field and inaccu- obturation. However, the successful outcome rate observations of the endodontic instru- of endodontic treatment depends to a large ments during the procedure. extent on accurate intraoperative findings. Endoscopy reportedly provides the den- Conventionally, micromirrors and micro- tist with excellent vision and ease of use. It probes have been used for this purpose. also provides better intraoperative visualiza- tion than micromirrors.3 In general, use of an endoscope in periradicular surgery is highly successful.4–6 However, published articles have evaluat- ed endoscopes only as a means for magnifi- cation and better monitoring of the working 1Associate Professor and Acting Chairman, Department of field. Further development of endoscopy Endodontics, The Hebrew University–Hadassah School of Dental Medicine, Jerusalem, Israel. made it possible to combine magnification, light, irrigation/suction, and surgical micro- 2Head, High Risk Dental Clinic, Barzilai Medical Center, Ashkelon, Israel. instruments in a single device. This combi-

3Professor and Chairman, Oral and Maxillofacial Surgery nation could lead to advanced root canal Department, Barzilai Medical Center, Ashkelon, Israel (affiliated treatment techniques. This article describes with Faculty of Medicine, Ben Gurion University of the Negev, the technical specifications and diagnostic Beer Sheva, Israel). and treatment application of the newly devel- Correspondence: Prof Oded Nahlieli, Department of Oral and Maxillofacial Surgery, Barzilai Medical Center, Ashkelon 78306, oped endoscope with the abovementioned Israel. Fax: 972 86745532. Email: [email protected] properties during endodontic procedures.

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Table 1 Patient data with good resolution. The instruments insert- ed from the working channel or parallel to the Patient no. Gender Age (y) Tooth no. endoscope were routine root canal instru- 1 Female 75 22(33) ments and microinstruments (irrigation and 2 Male 63 19(36) injection cannula [300-micron diameter], 3 Female 49 10(22) miniforceps, microdrills, needles, brushes, 4 Male 64 29(45) 5 Male 64 31(47) and diathermia probes). 6 Female 49 13(25) The endoscope was connected to a stan- 7 Female 63 3(16) dard endoscopic camera, illumination 8 Male 53 15(27) device, and videoendoscopy equipment. 9 Male 57 20(35) The miniature endoscope for root canal treat- 10 Male 57 18(37) 11 Male 43 20(35) ment basically consists of three segments: 12 Male 43 19(36) (1) a semiflexible examination probe, to be 13 Female 60 7(12) inserted into the root canal, including an 14 Male 58 17(38) ergonomic handle; (2) flexible optical-fiber 15 Male 55 6(13) connections for light transmission (distal) and image transmission (proximal); and (3) a rigid eyepiece with a cold light source con- MATERIALS AND METHODS nection and coupler for a high-quality charged-coupled device (CCD) camera. The flexible optical-fiber connection Patients enables the decoupling of the examination From January to April 2007, 12 patients (15 probe from the rigid eyepiece, which is heavy teeth) (5 females, 10 males, mean age 58.9) because of the CCD camera and its connect- were treated endodontically using the endo- ed cold light cable. The work can be per- scopic technique. The study was approved by formed using minimal effort while maintaining the Barzilai Medical Center Ethics Committee, excellent precision, just as with a purely hand- Ashkelon, Israel. The cohort of the study held instrument. included patients referred for endodontic For illumination, a bundle of randomly treatment of teeth with periradicular lesions of arranged optical fibers is employed, which strictly endodontic origin. Patients with sys- transmits light from the external cold light temic diseases were excluded from this study. source to the distal tip of the endoscope, Data are presented in Table 1. thereby utilizing the principle of total optical reflection at the boundary with an optically Materials thinner medium (ie, with a thinner index of The devices used were (1) a 2.2-mm modular refraction). With such small diameters, only endoscope with 3 channels for endodontic spatially aligned optical fibers can be used. instruments, suction, and a channel for the These relay the image fiber by fiber, spot by telescope (Sialotechnology)—the telescope spot, and also by way of total reflection. Thus, included 10,000-pixel telescope and a 0.9-mm the light intensity and color characteristics 120-degree lens, and (2) a 0.9-mm modular are transmitted via each optical fiber. endoscope with 2 channels, one for suction A correct optical image is ensured by a and another for the telescope (Sialo- lens at the distal end and an ocular telescope technology). The telescope included a 6,000- at the proximal end. Image quality is deter- pixel telescope and a 0.5-mm 70-degree lens mined by the quality of the optical fibers and and illumination fibers. the number of pixels. In practice, the number Both the 10,000- and 6000-pixel tele- of pixels possible is limited by the outer diam- scopes can be projected 7 mm apically. The eter of the endoscope and by the fact that 10,000-pixel, 120-degree lens gives the prac- each fiber cannot be smaller than a few titioner excellent resolution with an extra wide micrometers because of optical considera- field of view, and the 6,000-pixel, 70-degree tions. The extraordinary quality of the high- lens can penetrate small cavities and canals purity glass used and micro wide angle lens,

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120-degree 0.55-mm lens

0.90-mm

Fig 1a The 0.55-mm flexible telescope with 6,000 pixels and Nitinol light fibers and the 0.9-mm flexi- Light coating fibers ble telescope with 10,000 pixels and light fibers.

Fig 1b Flexibility of the nickel-titanium– Fig 1c Close-up view of the 0.9-mm tele- coated telescope. scope with 10,000 pixels and a 120-degree lens.

Fig 1d (left) The 2.2-mm modular endoscope with 3 channels. Fig 1e (above) The 0.9-mm modular endoscope with 2 channels.

Fig 1f Irrigation and injection cannula (arrow) inserted via Fig 1g Intrachannel brushes. Small brushes from 300 micron to 1 mm the instrument channel. The irrigation cannula can be are available for thorough cleaning of the root canal. advanced.

Fig 1h (left) All-in-one endo- scopic compact system. All the equipment needed for the endo- scopic procedure (camera, video, monitor, light source, and archive system) is combined in one laptop- like system.

Fig 1i (right) Intraoperative view during endoscopic root canal treatment.

combined with sophisticated production tech- the distal portion of the fibers. The endo- nology, is what makes imaging using the scope contains a channel for suction for the smallest of cross sections possible. telescope and surgical instruments. The illu- The optical part of Sialotechnology minia- mination fibers are around the optical fibers. ture endoscopes consists of an optical fiber The optical fibers and illumination fibers bundle in semiflexible and watertight were connected to an eyepiece and a standard cladding, a light guide, and a lens and eye- compact digital chip video camera linked to a piece lenses. The optical parts contain camera control unit and light source. (Figs 1a 6,000/10,000 fibers and a wide angle lens in to 1i)

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Table 2 Diagnostic and treatment data

Apical Patient no. Diagnosis Treatment radiolucency Percussion Pulpation Vitality

1* Root canal retreatment + + + 2 Irreversible pulpitis Root canal + 3 necrosis Root canal 4 Phoenix abscess Root canal + + + 5 Pulp necrosis Root canal 6 Phoenix abscess Root canal retreatment + + + 7 Phoenix abscess Root canal + + + 8 Pulp necrosis Root canal 9 Irreversible pulpitis Root canal + 10 Irreversible pulpitis Root canal + 11 Irreversible pulpitis Root canal + 12 Irreversible pulpitis Root canal + 13 Irreversible pulpitis Root canal + 14 Irreversible pulpitis Root canal + 15 Irreversible pulpitis Root canal +

*Resercin formalin was used.

Methods The endoscopic observation and treat- The procedures were performed using stan- ment (Fig 2) led to detection and removal of dard root canal equipment, which included the remaining dental pulp tissue following endodontic hand and rotary files, irrigating cleaning and shaping of the root canal walls solutions (saline, 3% sodium hypochlorite (Figs 3a and 3b). The dentin particles were solutions, 0.2% ) and the identified and removed following the videoendoscopy equipment. Basic treatment mechanical preparation (Figs 4a and 4b), was carried out by a professional, well- and irrigation and suction were applied trained endodontist. Following the mechani- through the endoscopic channels. Lateral cal preparation of the canal, the endoscope, canals (Fig 5) and microscopic root cracks connected to a video camera and monitor, were detected with high accuracy, providing was introduced with isotonic saline irrigation. better intraoperative judgment and facilitat- Remnants of the pulp tissue were coagulat- ing adequate treatment. ed by the diathermia monopolar fibers and During endoscopic treatment, bubbles removed with irrigation. The canal was then were observed at the apical terminus (Fig 6). inspected for lateral canals. Adequate irriga- The bubbles appeared within the visualizing tion was maintained throughout the proce- field when the tip of the endoscope reached dure by applying an intravenous bag the apical area and helped locate the apical connected to the irrigation port on the sheath terminus (bubble effect). of the endoscope. Another observation during treatment was a color change in the canal: The apical one- third of the root appeared red, probably because of the presence of the vascularized RESULTS tissue (periodontal ligament) and the transil- lumination effect (Fig 7). The endoscopic root canal treatment per- The files (hand- and engine-driven) and formed on 15 teeth was successful in all microinstruments helped remove debris and patients, (100%) with complete resolution of old obturation material and broken instru- all symptoms (6-month follow-up). The diag- ments and posts (Figs 8 to 10). nostic and treatment data are presented in Irrigation and suction were carried out via Table 2. the working channels under direct vision and improved the cleaning of the root canal from microdebris.

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Fig 2 (right) Intraoperative view of the 0.9-mm endo- scope inside the mandibular left first molar distal canal. Note the transillumination effect.

Figs 3a and 3b Endoscopic removal of the pulp tissue (arrows). (a) Endoscopic view via the 6,000-pixel endoscope and (b) with the 10,000-pixel endoscope.

Fig 4a Intraoperative endo- Fig 4b Endoscopic view of Fig 5 Endoscopic view of lateral canal (arrow) of the maxillary scopic view during mechani- dentin particles. left lateral incisor (the white material in the apical part is the cal preparation. remains of calcium hydroxide). Note the final periapical radiograph with the lateral canal filling.

Fig 6 (right) The bubble Fig 7 (right) Intraoperative effect. Arrows demonstrate endoscopic view during root the apical terminus in buccal canal endoscopy treat- and palatinal canals of the ment—note the difference maxillary left second pre- between the red and white molar. area (arrows). The red area demonstrates the apical one- third of the root.

Fig 8 Endoscopic removal of a fractured instrument with mini- Fig 9 Endoscopic insertion Fig 10 Endoscopic inser- forceps and microdrill.Arrow indicates the fractured instrument. of the microbrush. tion of irrigation and injection cannula.

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DISCUSSION DISCLOSURE

In the 21st century, as long as basic princi- Prof Oded Nahlieli is a consultant with Sialotechology ples of endodontic therapy are followed, the LTD Israel. equipment and tools available to clinicians increase the chances for a higher success rate. The introduction of microsurgical princi- ples in endodontics involving techniques REFERENCES used for canal treatment have tremendously improved visualization of the operating field.7 1. Keiser K. Magnification options in endodontics: A comparison of the operating microscope and the At the same time, the advent of microsurgical endoscope.Tex Dent J 2007;124:208–216. instruments and dental operating micro- 2. Taschieri S,Del Fabbro M,Testori T,et al.Use of a sur- scope has brought about advantages in root gical microscope and endoscope to maximize the canal instrumentation and the application of success of periradicular surgery. Pract Proced root canal filling materials.8 This develop- Aesthet Dent 2006;18:193–198. ment has facilitated the use of cleaning and 3. von Arx T, Frei C, Bornstein MM. Periradicular sur- shaping instruments, as well as root canal fill- gery with and without endoscopy: A prospective clinical comparative study. Schweiz Monatsschr ing techniques. The main purpose of this Zahnmed 2003;113:860–865. prospective case series was monitoring and 4. Filippi A, Meier ML, Lambrecht JT. Periradicular sur- treatment with the aid of magnification using gery with endoscopy: A clinical prospective study. newly designed endoscope. Schweiz Monatsschr Zahnmed 2006;116:12–17. The endodontic endoscope that was 5. von Arx T.Frequency and type of canal isthmuses in used in this study permits visualization, irri- first molars detected by endoscopic inspection dur- gation, as well as cleaning and shaping the ing periradicular surgery. Int Endod J 2005;38: 160–168. root canal. Optical cavity creation is crucial in 6. von Arx T, Montagne D, Zwinggi C, Lussi A. every endoscopy procedure. In endodontic Diagnostic accuracy of endoscopy in periradicular endoscopy, the authors found that the best surgery—A comparison with scanning electron medium is suction formation with low-pres- microscopy. Int Endod J 2003;36:691–699. sure vacuum via the channel and intermittent 7. Held SA, Kao YH, Wells DW. Endoscope—An irrigation with isotonic saline. Another option endodontic application. J Endod 1996;22:327–329. is to work with the endoscope in the channel 8. Bahcall JK, DiFiore PM, Poulakidas TK. An endoscop- in parallel with the instrument. ic technique for endodontic surgery. J Endod 1999;25:132–135. Further improvement of the endoscopic 9. von Arx T, Hunenbart S, Buser D. Endoscope- and technique involving a combination of several video-assisted endodontic surgery. Quintessence functions in one device, as in the endoscope Int 2002;33:255–259. used in this report, permits removal of mini- 10. Taschieri S, Del Fabbro M,Testori T, et al. Endodontic mal tooth structure. Such a minimally inva- surgery using 2 different magnification devices: sive approach is an important element in Preliminary results of a randomized controlled making the treated tooth less fragile in the study. J Oral Maxillofac Surg 2006;64:235–242. future.

CONCLUSION

In this study, adherence to a strict endodontic protocol and use of modern endodontic pro- cedures with visual magnifications resulted in an overall high success rate. Endoscopes that can be used for magnification, irrigation/ suction, and shaping may be very effective for root canal treatment.

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