Endo Tribune Middle East & Africa Edition No. 5, 2017

A2 ◊Page A1 ENDO TRIBUNE Dental Tribune Middle East & Africa Edition | 5/2017 tion. Hence, utilising EDTA to remove the smear layer prior to obturation but after completion of preparation and instrumentation is sensible. A penultimate rinse with EDTA then a ﬁnal rinse with hypochlorite prior to drying has been advocated heavily in the literature. Bacteria and the bioﬁlms Unlike what we once thought, bacte- ria do not tend to just sit alone and remote from each other. If only they were this antisocial and could be picked off one by one! Bacteria join forces and create symbiotic groups, share resources and protect each other from external inﬂuence. This is commonly known as a “bioﬁlm”, which has a thin but robust layer of mucilage that adheres to a solid surface housing the community of microorganisms. They not only share resources, they also share in- formation that promote each other’s survival through RNA or DNA. As the majority of bacteria will be encap- sulated in this layer, purely irrigat- ing without disrupting this layer is inefﬁcient. The word disrupting is a bit kind really—it needs to be de- stroyed to reveal all its contents and expose it to the bleach for chemical action. It is the methods of disrup- tion of the canal bioﬁlm that has seen a lot of development over the last 10 years or so. Much in the same way a pressure washer can clean that more quickly and efﬁciently than a sponge, energising the disinfectant results in improved cleanliness. Energising the irrigant This can take many forms. The simple and straightforward form ensures appropriate exchange of the ﬂuid and displacement into the recesses where airlocks may reside. This can be achieved through apply- ing a GP point into the prepared ca- nal to displace and disperse. Ultrasonic irrigation transmits ener- gy by an oscillating instrument. This results in two different phenomena. Cavitation is the growth and subse- quent collapse of small gas bubbles due to a drop in pressure. Acoustic streaming is the bulk movement of ﬂuid when pressure waves are pro- jected, resulting in vortex motion around a fast moving oscillating in- strument. This results in shear stress- es to tear the bioﬁlm apart. Keeping the canal clean Once irrigated and prepared, the cli- nician has a choice—to obturate or to dress. Some may argue that the canal is cleanest at the end of instru- mentation and that for convenience, obturating in a one visit arrange- ment is the best option. As we know, not all bacteria are removed or killed during treatment. Dressing the canal with calcium hydroxide may con- tinue the process of eradication of the residual microorganisms over a 2-week period. The choice between the two schemes sometimes boils down to the presenting factors of the case. Where a tooth is difﬁcult to instrument, has a large lesion or is quite obviously chronically infected with a history of pain, then dressing may be more of a consideration. If a tooth is treated in a de novo manner and treatment goals are achieved with no history of pain then a single visit treatment could be utilised. The goal of obturation is to seal the canal system to prevent any rein- fection and entomb any bacteria not eradicated by chemomechani- cal debridement. If the obturation is through the apex, this can have signiﬁcant implications. GP through the apex can carry bacteria outwith of the canal and exacerbate symp- toms. A foreign body reaction could also develop. We also have to remember that a beautiful obturation of a canal achieved without rubber dam and utilising saline or local anaesthetic irrigation is sub-standard treatment. It can be difﬁcult to assess the “qual- ity” of treatment when a radiograph of a “failed” tooth is examined in this context. Indeed, an obturation that is short of the radiographic apex having been treated under rubber dam and with copious amounts of irrigation is more likely to be suc- cessful than the previous scenario. Attributing too much signiﬁcance to the radiographic appearance of the obturation is short-sighted. Indeed, Katebzadeh and colleagues in the late ‘90s witnessed healing in the absence of obturation where teeth where instrumented and irrigated optimally under isolation. Sealants are also antibacterial and aide ﬁlling the voids between the GP and the canal system. One further option would be to provide a sub-seal to each of the canal oriﬁces. This can be achieved by removal of 1 mm of GP and packing a good thick mix of IRM packed with a plugger. Covering the cusps The provision of a coronal restora- tion (if provided optimally) can improve the coronal seal while also structurally protecting the underly- ing tooth tissue. Due to endodontic treatment, resulting in reduction of tissue bulk and stiffness the risk of fracture increases. Where both mesial and distal margins have not been breached and the access cavity is conﬁned to the occlusal surface, a crown restoration may not be re- quired. Once a margin is breached the tooth is more likely to ﬂex and result in cracks or fractures. A com- monly asked question, “When should the crown be provided? Soon after the root canal treatment or when the treatment has proven to be successful?” If the success of en- dodontic treatment is signiﬁcantly in doubt then this should be com- municated to the patient and a well compacted direct restoration may be the best option, otherwise an on- lay or if tooth tissue is signiﬁcantly reduced, a crown should be provided soon after completion. Conclusion Bacteria are public enemy number one in dentistry. Disinfecting the root canal system by irrigating in combination with mechanical in- strumentation is key to success in root canal therapy. Preventing fur- ther re-infection or persistence of residual bacteria after the formal stages of treatment through dress- ing initially and a quality coronal seal subsequently is as important as the root canal therapy. Editorial note: The article was pub- lished in Roots Magazine Internation- al 2/2017 Aws Alani, UK He is a Consultant in Restorative Dentistry at Kings College Hospital in London, UK. He can be contacted at: awsalani@hotmail.com. www.restorativedentistry.org All roads lead south By Dr Alfredo Iandolo, Italy As usual in the human anatomy, root canals come in all forms and sometimes develop in very random structures. Luckily, pre-bendable nickel titanium (NiTi) ﬁles allow us to prepare and clean the canal in next to no time. In this article, we will compare three different endodon- tic cases, you will quickly ﬁ nd that a thorough and efﬁcient root canal preparation is easy with the right set of instruments—regardless of the shape of the canal itself. Reading endodontic case reports, you sometimes get the impression that root canals always spot an ex- treme, double curved morphology. With the latest technology and treat- ment auxiliaries the endodontic world has to offer, you should, of course, feel conﬁdent to take on even the most unusual shapes of canals. Would not it be nice though to have a universal, ﬂexible NiTi ﬁle system that allows you to prepare all sorts of canals, whether they are S- or J- shaped or lead straight down to the apex? In Italy, we say “tutte le strade portano a Roma”. For a well-versed endo expert “all root canals lead to the apex is just as true—you only have to know how to use your equip- ment the right way”. Case 1: Straight down to business A 48-year-old female patient intro- duced to our surgery complaining of pain caused by chewing in the maxil- lary left side. We quickly found that the necrotic pulp of tooth 24 caused the complaint. The pre-operative radiograph showed a deep caries as well as a medium-sized periapical le- sion (Fig. 1). The root canals were positioned in a comparatively straight, almost par- allel way with hardly any curvature. Quick preparation with a reduced sequence of NiTi ﬁles consequently should be possible in that particular case, as there were no contraindica- tions to a root canal therapy in gen- eral. To provide a clean and dry operat- ing ﬁeld, dental dam was applied to isolate tooth 24 for the following treatment. First of all, we handﬁled the main canals up to ISO 10 size. We were thus able to create a suitable glide path, before the actual prepara- tion took place. In our endodontic practice, we nor- mally use the latest generation of nickel titanium ﬁles by Swiss den- tal specialist COLTENE for cleaning and shaping the canal. As the name already indicates, the HyFlex EDM is a “highly ﬂexible” NiTi ﬁle, which proves to be incredibly fracture re- sistant. In close cooperation with leading universities and internation- al endo-specialists, the renowned research department of the innova- tive provider of endo equipment de- veloped a literally sharp solution for their instruments. To come up with a new, powerful tool they employed a clever idea that is widely used in other industry branches to dentistry. The abbreviation “EDM” stands for a speciﬁc manufacturing process named “electrical discharge machin- ing”. Spark erosion improves the cut- ting performance of the instrument as it produces a unique surface in the ﬁle. You can compare this kind of reﬁnement with the serrated edge of a kitchen knife you use for cutting bread to make bruschetta (Fig. 2). Due to its special material proper- ties, the ﬁle is virtually unbreakable and predestined for dentists who re- quire fast and reliable results using a reduced ﬁle sequence. With the HyFlex EDM, we were able to prepare the root canal system in the blink of an eye. Access was quickly gained with the HyFlex 25/.12 Oriﬁce Opener (Fig. 3). For the main procedure we used only one univer- Fig. 1: Pre-operative radio- graph of case 1 Fig. 2: Specially hardened surface of the HyFlex EDM ﬁle under the microscope Fig. 3: Cutting in the canal using a HyFlex EDM 25/.12 Oriﬁce Opener. the sal ﬁle that saved a lot of time during the treatment. For a quick and thorough preparation, a size 25 ﬁle with variable taper was applied in common single length tech- nique. The shaping took only a couple of minutes and we were able to navi- gate the instrument swiftly through the canal in a soft peck- ing motion (Fig. 4). Even when a bit more pressure was put on the ﬁle it nei- ther blocked nor got stuck in the dentine. Fig. 4: HyFlex EDM OneFile To obtain the ideal chemomechanical cleansing we then irrigated the canal several times for a total of at least 30 minutes. Following the classic irrigation protocol, we used intracanal heated so- dium hypochlorite (Iandolo technique), 17 % EDTA solu- tion and 2 % chlorhexidine digluco- nate solution to remove all debris and possible irritants from the canal. After eradicating the infection, we dryed the canal with the correspond- ing paper points size 25. The last step was to create a proper seal to prevent microorganisms from reentering the root canal system and thus pro- tect the root from future recontami- nation. A bioactive 3-in-1 obturation material was applied in a special technique as described in the follow- ing case to ensure that all lateral and side canals were ﬁlled. The postoper- ative radiograph after the treatment most notably showed a lateral canal in the apical third as well as an isth- mus between the main canals, which got both ﬁlled safely (Fig. 5). The re- sult was a tight, durable seal of the whole root canal system, as the ﬁnal radiograph reﬂected (Fig. 6). Case 2: 3-D obturation technique In our second case, a 65-year-old female patient was referred to our practice with chief complaint of pain in the right side mandible. The radio- graph showed defects in two teeth: in tooth 45, an insufﬁcient former root canal treatment had led to a per- iapical lesion. In the neighbouring molar, a deep restoration was clearly visible. Tooth 46 was therefore diag- nosed with a necrotic pulp (Fig. 7). Again, the HyFlex EDM helped us to shape the canal effectively without transporting or changing the natural path of the root canal. After gaining access with the oriﬁce opener, we once again used the HyFlex OneFile to get to the apex. A few ﬁnishing touches were provided with the help of a 40/.04 EDM ﬁle. Obturating all portals of exit turned out to be particularly challenging in our second case, therefore a modi- ﬁed three-dimensional obturation technique was applied using Gut- taFlow bioseal. The 3-in-1 obtura- tion material combines ﬂuid gut- ta-percha with a suitable sealer at room temperature and bioceramics in an automix syringe (Fig. 8). This composition results in an easy to handle material with excellent ﬂow properties and working times of 10 to 15 minutes. What we call three- dimensional obturation technique is, in fact, an efﬁcient and reliable way to ﬁll even complex root canal structures. ÿPage A3

Endo Tribune Middle East & Africa Edition No. 5, 2017

Pages Overview