Controlling intra-oral infection
‘Endodontology is concerned with the form, function and health of, injuries to and disease of the dental pulp and periradicular region, their prevention and treatment.’1 When the pulp is subject to continued stimulation from micro-organisms, the inevitable result is its irreversible destruction and complete breakdown. Consequently, the inflammatory process may spread beyond the confines of the pulp chamber and into the periapical tissues.
The main aim of treatment is the ability to control the intra-canal infection. Root canal treatment is performed with the intention of thorough mechanical and chemical debridement of the entire pulp space followed by complete obturation with an inert filling material.
Success is measured in terms of clinical signs, symptoms and radiographic evidence of healing. The decision to use certain dental materials is vital when looking to establish long-term clinical success.
A 19-year-old medically fit female attended complaining of a throbbing ache/swelling localised to the UL6. After a thorough history and examination, a diagnosis of apical periodontitis of the UL6 was made. Treatment options were discussed, following which treatment entailing prevention, restorative and endodontic care was undertaken.
The UL6 required a conventional root canal. Using the American Endodontic Case Difficulty Form2 it was deemed to be of minimal to moderate difficulty. Informed consent was gained explaining the benefits, risks, alternative options for procedure and treatment. Prognosis was assessed to be good.
Treatment was performed in one visit3 under rubber dam and anaesthesia, which helped in managing the patient’s anxiety. The access cavity was prepared prior to placement of the rubber dam. The aim was to achieve straight-line access and to preserve tooth tissue.4 Further refinement was performed using an ultrasonic scaler and a long neck round bur to remove dentine overlying the canal orifices. Magnification (3.2% orascoptic loupes with illumination) and a DG16 probe was used to find the MB2 canal. Disinfection was performed using a small gauge needle (30) and 3% sodium hypochlorite (NaOCL) and 17% EDTA solution (SK Cleanser). Coronal third shaping was then performed with copious irrigation throughout using Gates-Glidden burs. An electronic apex locator (Root ZX,J.Morita Corp) was used to determine working length5 and canal patency was obtained using a size 10 stainless steel K-file. Apical preparation was then performed using a size 30, .06 taper Profile NiTi rotary instrument (Dentsply Maillefer) lubricated with EDTA (SK Chelcream). A strict irrigating regime was employed throughout the cleaning and shaping phase of treatment (Figure 4). The technique used to obturate the three canals was cold lateral condensation followed by thermo compaction of gutta percha (SK Gutta Percha Points 0.06) using a gutta condenser and SK Seal. Coronal seal was then obtained using SK Seal to seal the GP followed by a flowable composite (SK Flow) and a final composite restoration (Skadacomp).
A post-operative peri-apical of the UL6 showed the final outcome was good and upon a week review the patient was symptom free.
The aim of the treatment provided to the patient was based on integrating the best evidence with clinical knowledge and dental materials. The following areas warrant further discussion regarding the treatment provided:
1. Why were EDTA solution (SK Cleanser) and EDTA cream used (SK Chelcream)?
Chelating agents such as ethylenediaminetetraacetic acid (EDTA) are used for the removal of the inorganic portion of the smear layer.6 NaOCl is an adjunct solution for removal of the remaining organic components. Irrigation with 17% EDTA for one minute followed by a final rinse with NaOCl is the most commonly recommended method to remove the smear layer.7
Advantages encountered when using SK Cleanser and SK Chelcream:
• Chelating affect allowed for better file penetration
• Enhanced enlargement of the canals for debridement
• Excellent dissolution affect of pulp remnants
• Optimal removal of smear layer.
2. What were the benefits of using SK Seal as a root canal sealer?
SK Seal is a non-eugenol, calcium hydroxide based root canal sealer available in an automix delivery system. Ca(OH)2 is a substance that inhibits microbial growth in canals.8 The antibacterial effect of Ca(OH)2 is due to its alkaline pH. It also dissolves necrotic tissue remnants and bacteria and their byproducts.9
The advantages encountered when using SK Seal are as follows:
• No manual mixing required due to automix syringe application resulting in an optimal and consistant mix. Mixing and handling were found to be exceptional
• Non irritating, lowering the risk of postformulation operative sensitivity
• Stimulates hard tissue formation
• Favourable working time (35min), setting time (45.33min), flow (44.08mm) and radiopacity (5.44mm/mmAl).
3. What are the benefits of using Ni-Ti instruments?
The advantages of using rotary instruments are as follows:
• More effective debris removal coronally
• Centered in canal – much less likely to ledge
• Predetermined taper
• Predictable shape
Studies show that there are fewer procedural errors and better shaping ability of the Ni-Ti instruments in comparison to stainless steel K-file. However, there are few reports to show any significant differences between the two instruments.10
4. Why was no extra coronal restoration provided?
Firstly, studies have shown that the quality of the coronal seal has a significant effect on the outcome of endodontic treatment.11 Leakage can be reduced by the placement of adhesive restoration (SK Flow) placed over the gutta-percha followed by provision of a well-sealed permanent filling.4
In this case, the marginal ridges of the UL6 were intact following treatment. This suggested the tooth was less liable to fracture and more likely to withstand ‘wedging’ forces developed during function.12
Evidence suggests that RCT does not change the quality of dentine, except some moisture loss (increase in brittleness), and it is thought that weakening of the tooth is more as a result of tooth tissue loss.12 Therefore, an extra-coronal restoration was not provided and rather form and function built up using Skadacomp (Nano Hybrid composite material.) Skadacomp was used as it shows increased flexural (163.66Mpa), compressive (347.9Mpa) and diametral tensile strength, required in order to endure load in such a stress bearing area.
5. How is the tooth going to be monitored for success?
According to the BES1, the RCT should be assessed at least after one year. These indicate a favourable outcome:
• Absence of pain/swelling/sinus tract
• No loss of function
• Radiological evidence of normal periodontal ligament space around the tooth.
Best evidence and knowledge
The case demonstrates a predictable technique, integrating best evidence with clinical knowledge and the use of specific endodontic materials to ensure success. Upon a six-monthly review the tooth had responded favorably to treatment and the patient had no symptoms or complaints.
1. Endodontology, European Society of. Quality guidelines for endodontic treatment: consensus report of the European Society of Endodontology. 921–930, s.l. : International Endodontic Journal,, 2006., Vol. 39.
3. Lara Figini1, Giovanni Lodi2, Fabio Gorni3, Massimo Gagliani4.Single versus multiple visits for endodontic treatment of permanent teeth. 4, s.l. : Cochrane Oral Health Group., August 20 , 2007.
4. Qualtrough AJE, Satterthwaite JD,Morrow LA, Brunton PA. Principles of Operative Dentistry. s.l. : Blackwell Munksgaard, 2005.
5. Simon, Stephane, Lumley P, Adams N. Apical limit and Working length in Endodontics., s.l. : Dental update, 2009, Vol. 36. 146-153.
6. Torabinejad M, Handysides R, Khademi A, Bakland LK. Clinical implications of the smear layer in endodontics: A review. Oral Surg Oral Med Oral Pathol Oral Radiol Endod.
7. Johnson WT, Noblett WC. Cleaning and Shaping in: Endodontics: Principles and Practice. 4th ed. Saunders, Philadelphia, PA.
8. Law A, Messer H. An evidence-based analysis of the antibacterial effectiveness of intracanal medicaments. J Endod 2004;30:689-94.
9. Yang SF, Rivera EM, Baumgardner KR, Walton RE, Stanford C. Anaerobic tissue-dissolving abilities of calcium hydroxide and sodium hypochlorite. J Endod 1995;21:613-6.
10. Cheung G, LiuC. A Retrospective Study of Endodontic Treatment Outcome between Nickel-Titanium Rotary and Stainless Steel HandFiling Techniques. 7, s.l. : American Association of Endodontists, July 2009, Vol. 35.
11. Saunders W.P, Saunders E.M. Coronal leakage as a cause of failure in root-canal therapy: A review. 105-8, s.l. : Endod Dent Traumatol, 1994, Vol. 10.
12. Hansen, E.K and Asmussen E.In vivo fractures of endodontically treated posterior teeth restored with MOD-amalgam or MOD resin fillngs. 169-73, s.l. : Dent Mater, 1988, Vol. 4
• Irrigate copiously and frequently with room temperature 3%NAOCl during mechanical preparation
• Every third irrigation, EDTA used (SK Cleanser)
After shaping complete:
• Two minutes with NaOCl- GP cones were tried for length with NaOCl insitu. This allows for displacement of NaOCl solution into lateral canals (mechanical activation)
• One minute EDTA + U/s followed by NaOCl- to remove smear layer
• Final flush saline.
Throughout the procedure, a small gauge needle (30) was placed loosely in the canal, which allowed the correct application of the irrigant and hydrodynamics. For the apical third, the needle was bent 2-3 mm shorter than the working length in order to prevent extrusion of the irrigant through the apex.
Unit D, HealthAid House, Marlborough Hill, Harrow, Middlesex HA1 1UD