Endo Tribune United Kingdom Edition

ENDO TRIBUNE The World’s Endodontic Newspaper · United Kingdom Edition Published in London www.dental-tribune.co.uk CASE REPORT Dr Vittorio Franco explains treat- ment of a 22-year-old male pa- tient with a history of trauma to his maxillary incisors. ” Page 20 Cleaning is key By Aws Alani, UK INTERVIEW Dental Tribune spoke with Dr Craig Barrington, USA, about his technique for capturing high-deﬁ - nition endodontic images. is coming to BERLIN Vol. 11, No. 9 ROOTS SUMMIT Everything to know about the most international event in endodontics in 2018. important ” Page 22 28 June –1 July 2018 Berlin, Germany www.ROOTS-SUMMIT.com ” Page 23 Completely disinfecting the canal system is challenging when all fac- tors are considered. If we are look- ing at the nano level there are ap- proximately 76,000 dentinal tu- bules per square millimetre of den- tine. Each of which can harbour a colony of bacteria. Then there may be inaccessible anatomy such as lateral canals, apical deltas or ﬁ ns. in combination with hand ﬁ ling signiﬁ cantly reduced bacterial load. As such chemomechanical instrumentation was shown to be crucial for endodontic success. They compared irrigation with sa- line, 0.5 and 5 % hypochlorite over a sequence of 5 appointments. In- terestingly they found no differ- ence in the reduction of bacterial It seems that irrigation and in- strumentation are both highly in- ter-related in canal disinfection. Take washing your car for in- stance, purely covering it with soapy water and rinsing won’t re- move the motorway bugs and bird produced projectiles. A good scrubbing with a sponge is needed, or if you are really serious about from the dentine. The smear layer prevents bacteria residing in the dentinal tubules from being ex- posed to the irrigant as well as re- ducing the contact between the dentine and sealant during obtu- ration. Hence, utilising EDTA to remove the smear layer prior to obturation but after completion of preparation and instrumenta- © Dzmitry Held/Shutterstock.com These are factors that need consid- ering outside of canal curvatures that may or may not be entirely vis- ible in the plane of the radiograph. It is clear that outside of the contact our ﬁ les make with the walls of the root canal there needs to be chemi- cal disinfection to further reduce bacterial load. Irrigants disinfect as well as lubricate instruments and they dissolve the pulp. Sodium hypo chlo rite has been the mainstay irrigant for decades. During the 1980s, Bystrom and colleagues investigated the ef- fect of mechanical instrumenta- tion with and without adjunctive use of hypochlorite. They found, unsurprisingly so, that when com- pared to pure mechanical instru- mentation, the use of hypo chlorite load between 0.5 and 5 % hy- pochlorite. Despite what was likely to be a comprehensive protocol for these teeth, 7 of the 15 speci- mens in this study still had bacte- ria that they could grow at the end of treatment. The presence of cul- tivable bacteria does not necessar- ily mean we have failure—it merely means that there may be a cohort of bacteria that have re- sisted treatment. Mechanical in- strumentation does reduce bacte- rial load by itself—this is by way of physical removal of tissues where bacteria reside, while also facilitat- ing the dispersal of the irrigant into the canal. Siquiera and col- leagues found that enlarging the canal from size 30 to 40 resulted in a signiﬁ cant decrease in endodon- tic pathogens. cleaning, a pressure washer! This begs a further question—how would your patients feel if they knew that, more or less, the same or very similar liquid they use to clean bathroom suites is the same that we use to clean the inside of their teeth? On recent evidence of a dentist to the “stars” appearance on national TV not much—he ad- vocated using charcoal to whiten teeth, which you may be able to buy from your local petrol station for barbecues. Hypochlorite is an effective bactericidal but does not remove the smear layer. The smear layer is a mix of organic material (protein, pulp remnants, saliva, microor- ganisms) with an inorganic com- ponents consisting of minerals tion is sensible. A penultimate rinse with EDTA then a ﬁ nal rinse with hypochlorite prior to drying has been advocated heavily in the literature. Bacteria and the bioﬁ lms Unlike what we once thought, bacteria 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 exter- nal inﬂ uence. This is commonly known as a “bioﬁ lm”, which has a thin but robust layer of mucilage that adheres to a solid surface housing the community of micro- organisms. They not only share re- sources, they also share informa- tion that promote each other’s sur- vival through RNA or DNA. As the majority of bacteria will be encap- sulated in this layer, purely irrigat- ing without disrupting this layer is inefﬁ cient. 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 disruption of the canal bioﬁ lm 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 ef- ﬁ ciently than a sponge, energising the disinfectant results in im- proved cleanliness. Energising the irrigant This can take many forms. The simple and straightforward form ensures appropriate exchange of the ﬂ uid and displacement into the recesses where airlocks may re- side. This can be achieved through applying a GP point into the pre- pared canal to displace and dis- perse. Ultrasonic irrigation transmits energy by an oscillating instru- ment. This results in two different phenomena. Cavitation is the growth and subsequent collapse of small gas bubbles due to a drop in pressure. Acoustic streaming is the bulk movement of ﬂ uid when pressure waves are projected, re- sulting in vortex motion around a fast moving oscillating instru- ment. This results in shear stresses to tear the bioﬁ lm apart. Keeping the canal clean Once irrigated and prepared, the clinician has a choice—to ob- turate or to dress. Some may argue that the canal is cleanest at the end of instrumentation and that for convenience, obturating in a one visit arrangement is the best op- tion. As we know, not all bacteria are removed or killed during treat- ment. Dressing the canal with cal- cium hydroxide may continue the

Endo Tribune United Kingdom Edition

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