Today’s Endodontic Therapy Driven By Advances in Technology, Changes in Thinking
Innovations in instrumentation, obturation, visualization, and surgical techniques are enabling clinicians to provide better long-term prognoses for their patients’ teeth after endodontic treatment. Future trends in endodontics include regeneration techniques and the use of 3-D printing.
Prior to the early 1990s, conventional endodontic treatment was performed with stainless-steel hand files for canal preparation and cold lateral gutta-percha compaction for canal obturation. Visualization during treatment was often without any magnification (ie, dental loupes), and the two dimensions of a standard wet tank processed dental radiograph were a clinician’s only guide for determining the correct working length of a root canal system.
Since that timeframe, the field of endodontics has embraced technological advancements and changes in thought processes in regards to root canal therapy. Today’s innovations in instrumentation, obturation, visualization, and surgical techniques have enabled dentists to provide better long-term prognosis for their patient’s tooth or teeth after endodontic treatment.1,2
Instrumentation
With the development of nickel-titanium for endodontic files,3 rotary nickel-titanium files have provided dentists with a more consistent, efficient, and effective means of performing endodontic treatment in comparison to stainless-steel hand filing.4 Along with the change in the metal of a file, rotary endodontic files have increased tapers and various cross-sectional designs as compared to hand files. These file refinements help rotary instruments to better shape and prepare a canal for irrigation and obturation.
Currently, there is a trend in reciprocating file usage for nonsurgical endodontic treatment. Reciprocating files have been shown to require a fewer number of actual files to prepare a root canal system as compared to rotary files. Also, reciprocating files have demonstrated better cyclic fatigue resistance against file separation.5 As with any technology, over the next few years there will continue to be advancements through improvement in reciprocating file design and efficiency by the manufacturers. Also, over the next several years, more clinical research on reciprocating files will undoubtedly be published to help clinicians make evidence-based decisions on whether this methodology for endodontic treatment warrants a change from their current rotary file system.
Another important instrument used in today’s endodontic treatment is the apex locator. Current technology has made the apex locator an accurate instrument in helping dentists determine a canal’s working length by detecting the cemento-dentinal junction (CDJ) or maximum constriction of the canal’s apical foramen.6
The addition of ultrasonic and sonic instrumentation as a part of the endodontic treatment armamentarium has enabled dentists to better locate calcified canals, prepare root-ends in endodontic surgery, and/or clean residual canal debris from the canal walls after endodontic canal preparation.7
Irrigation and Obturation
Although endodontic files remove a significant portion of the vital or necrotic pulp tissue within a canal, the complex canal anatomy of a root canal system can prohibit a file from removing pulpal tissue in lateral canals, isthmuses, and deltas. Therefore, endodontic treatment is significantly more effective when biomechanical preparation is performed with the combination of mechanical instrumentation and various irrigating solutions.8 Sodium hypochlorite (NaOCl) is still considered the irrigant of choice in endodontic treatment due to the fact that it can dissolve vital and necrotic pulp tissue and has antimicrobial effects. Sodium hypochlorite, however, is not capable of dissolving the inorganic components of the smear layer and, therefore, needs to be used in combination with ethylenediamine tetra-acetic acid (EDTA).
Chlorhexidine (CHX) is another medicament used in today’s endodontic canal irrigation in necrotic pulp cases. CHX has antimicrobial effects, substantivity, and low toxicity. The main reason that CHX does not replace the use of NaOCl in endodontic therapy is because it does not have tissue-dissolving properties.
The use of thermoplastized gutta-percha is the current trend in endodontic obturation. When it comes to replicating a root canal system, warm vertical technique is significantly better than cold lateral gutta-percha compaction.9 The vertical compaction of warm gutta-percha is an effective method to achieve 3-dimensional (3-D) obturation in a canal space. It is important to note that with warm gutta-percha obturation techniques, an endodontic sealer is still required as used in cold lateral gutta-percha obturation.
Visualization
Visualization of surgical and conventional endodontic treatment has historically been limited to the two dimensions of a dental radiograph that represents a 3-D biological system. Today, endodontics is viewed as a microsurgical procedure. The basic finding upon all microsurgery is the need for a clinician to view a magnified treatment field. The use of loupes, microscopes, and endoscopes in endodontic treatment has enabled the endodontist/dentist to magnify a specified treatment field beyond that of the naked eye.
The use of magnification in endodontic treatment enhances the ability of the clinician to better identify and treat etiology of endodontic origin. It also helps a dentist identify fracture lines, locate canal orifices, and determine anatomic variations in teeth and supporting structures.
Radiography
The use of digital radiographs has enabled the dentist to capture, view, magnify, enhance, and store endodontic radiographic images in a format that does not degrade over time. The viewing of a digital endodontic radiograph on a high-resolution monitor allows for rapid and easy interpretation by the clinician.
Cone-beam computerized tomography (CBCT) technology has further advanced the ability of a dentist to better interpret root fractures and endodontic pathosis when making an endodontic diagnosis and prognosis assessment. Unlike a 2-dimensional (2-D) radiograph, CBCT can provide early detection of pathosis in cancellous bone while eliminating the superimposition of anatomic structures. CBCT is not a replacement for the conventional digital radiograph, but rather is used as an adjunct when a more 3-D field of view is required for diagnosis.
Endodontic Surgery
There have been significant advancements in endodontic surgery over the past 20 years. The use of magnification (ie, surgical operating microscope and endoscope), ultrasonic tip root-end preparation, micro instruments, and newer retrofill materials are some of the major advancements. In a study by Tsesis,2 the authors reported that modern surgical endodontic treatment using magnification and ultrasonic tips significantly improved the outcome as compared to traditional endodontic surgical techniques.
Future Trends in Endodontics
As with any healthcare field, technology and research help to advance patient care through better prevention, diagnosis, and prognosis after treatment. The field of endodontics is no exception. Some of the future trends in this field are regenerative endodontics and the use of 3-D printing.
Regenerative endodontics is defined as a biological procedure that can replace a tooth hard tissue along with cells of the pulp.10 Although this regenerative science dates back more than 50 years, it has been over the past 10 years that the endodontic literature has demonstrated significant clinical success in endodontic regeneration techniques.11 The future science of regenerative endodontics will continue to become more clinically applicable for dentists to be able to provide this type of tooth regenerative therapy for their patients.
Current advances in endodontic surgery have been a result of technological advancements and changes in procedures. Although these advancements and procedural changes have improved surgical treatment outcomes, presurgical case assessment is still hampered by the limitation of interpreting 2-D radiographic representation of a 3-D in vivo surgical field. The recent integration of CBCT technology in endodontic surgery has significantly improved the 3-D imaging of the 2-D dental radiograph. The ability to transform the CBCT image into a pre-surgical model through 3-D printing provides a “true” 3-D imagery of the in vivo endodontic surgical site.12 The future use of 3-D printing in conventional endodontic treatment will provide dentists with a pretreatment model of a canal and/or root structure.
References
1. Salehrabi R, Rotstein I. Endodontic treatment outcomes in a large patient population in the USA: an epidemiological study. J Endod. 2004;30(12):846-850.
2. Tsesis I, Rosen E, Schwartz-Arad D, Fuss Z. Retrospective evaluation of surgical endodontic treatment: traditional versus modern technique. J Endod. 2006;32(5):412-416.
3. Walia HM, Brantley WA, Gerstein H. An initial investigation of the bending and torsional properties of Nitinol root canal files. J Endod. 1988;14(7):346-351.
4. Short JA, Morgan LA, Baumgartner JC. A comparison of canal centering ability of four instrumentation techniques. J Endod. 1997;23(8):503-507.
5. Kiefner P, Ban M, De-Deus G. Is the reciprocating movement per se able to improve the cyclic fatigue resistance of instruments? Int Endod J. 2014;47(5):430-435.
6. Martins JN, Marques D, Mata A, Carames J. Clinical efficacy of electronic apex locators: systematic review. J Endod. 2014;40(6):759-777.
7. Bahcall JK, Olsen EK. Integrating ultrasonic tips into your endodontic treatment armamentarium. Dent Today. 2007;26(5):120-123.
8. Paiva SS, Siqueira JF Jr, Rocas IN, et al. Clinical antimicrobial efficacy of NiTi rotary instrumentation with NaOCL irrigation, final rinse with chlorhexidine and interappointment medication: a molecular study. Int Endod J. 2013;46(3):225-233.
9. Leduc J, Fishelberg G. Endodontic obturation: a review. Gen Dent. 2003;51(3):232-233.
10. Murray PE, Garcia-Godoy F, Hargreaves KM. Regenerative endodontics: a review of current status and a call for action. J Endod. 2007;33(4):377-390.
11. Bansal R, Jain A, Mittal S, et al. Regenerative endodontics: a road less travelled. J Clin Diagn Res. 2014;8(10):ZE20-ZE24.
12. Bahcall JK. Using 3-dimensional printing to create presurgical models for endodontic surgery. Compend Contin Educ Dent. 2014;35(8):e29-e30.
