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Composite restorations have now become a part of our daily routine in dentistry. Most of the carious lesions are present in dentin. Dentin has always been the best protection that pulp can have. So, while removing dentin for caries excavation we need to keep in mind that dentin permeability increases as we approach the pulp as the diameter of dentinal tubules increases. This makes it more permeable to chemicals that are used during the restorative procedure. Therefore, etching the dentin for long periods is going to cause pulp fluid displacement which is going to trigger the odontoblasts and stimulate a painful response.2 Clinical studies on sensitivity arising after resin composite restorations have reported a frequent and very variable prevalence of between 0 and 50% (3–7), with predominance in posterior teeth and Class II restorations. 1 Similar problem occurs while placing composite in the cavity. While layering the composite if a small void remains in the composite there is going to be movement of the fluid in that small pocket of air which the patient is going to perceive as pain. 8,9 Whatever the reason we have to tackle the situation of dentinal fluid movement. The only predictable way to achieve this is a technique as described by Pascal Magne ie Immediate Dentin Sealing. To see how IDS is done we are soon coming out with a technique video for the same. Stay tuned. Till then go through the free article written by the inventor himself i.e. Pascal Magne on Immediate Dentin Sealing. Click here to download the PDF. Post-operative sensitivity on direct resin composite restorations: clinical practice guidelines. IJRD January 2012 Akpata ES, Sadiq W (2001) Post-operative sensitivity in glass-ionomer versus adhesive resin-lined posterior composites Am J Dent 14, 34–38 Lienfelder KF, Bayne SC, Swift EJ Jr (1999) Packable composites: overview and technical considerations. J Esthet Dent 11, 234–249. Casertani RSA, Pfeifer CSC, Braga RR (2007) Influência da técnica de inserção e do modo de fotoativação na microinfiltração de restauração de CIV em compósito. Scientifc- A 1, 54–59 (in Portuguese). Dijken JWVD, Grönberg KS (2206) Fiber- reinforced packable resin composites in class II cavities. J Dent 34, 763–769. 6. Yamazaki PCV, Bedran-Russo AVB, Pereira PNR, Swift-Junior ED (2006) Microleakage evaluation on a new low-shrinkage composite restorative material. Oper Dent 31, 670–676. Buonocore MG (1955) A simple method of increasing the adhesion of acrylic filling materials to enamel surfaces. J Dent Res 34, 849–853. Baratieri LN. Ritter AV, Perdigão J, Felipe LA (1998) Direct posterior composite resin restorations: current concepts for the technique. Pract Periodont Aesthet Dent 10, 875–886. Dietschi D, Spreafico R (1997) Adhesive metal free restorations: current concepts for the esthetic treatment of posterior teeth. ChicagoQuintessence Books, Chicago, IL.

The most critical factor in the predictability of composite restorations is placing a rubber dam. Placing a rubber dam with retainer and band in deep proximal defects is extremely challenging. Clinically, what I have experienced is that the rubber dam does not get completely tucked below the cervical margin of the tooth. It bounces back coronally due to the presence of interdental papilla. An easy way to get away with this difficulty is to ablate the interdental gums to expose the cervical margin. Though these gums grow again, it takes more than 3 weeks for the papilla to fill the space. A common patient complaint due to the empty space is food impaction. How should we retract the rubber dam below the cervical margin of the tooth without ablating the gums? The easiest way to tackle this situation is to use a teflon or a floss tie. My personal preference is teflon because floss ties loosen up due to which the rubber dam comes up coronally. We need to place teflon by the Bilaminar technique to avoid this problem. The detailed explanation of isolating deep class II cavities and the bilaminar technique of Teflon placement are part of our ONLINE / OFFLINE RUBBER DAM COURSE. Click here to know more.

Rotary files have come a major way in making endodontic treatment predicatble1. They are a boon to endodontics as they save a lot of time in shaping the canal so that maximum time can be dedicated to irrigation2. However it becomes a tragic moment when we have a broken file in the canal. Before explaining you the 2 reasons of file breakage one should understand that files from all manufacturers are good. So “WE” are the main reason why file separates from the canal. So if you are a first time user of rotary files or if you want to kick start your endodontic practice by incorporating rotary files, do join our ENDOFINISHER COURSE. Click here to enroll. It is a common feature of NiTi instruments to fracture without any warning signs. Unlike stainless steel instruments that show a visible sign of deformation, there are no such signs seen with NiTi unless viewed under magnification.3,4,5 So NiTi instruments can fracture because of two reasons-Torsion and Fatigue. Torsion: Example of torsion failure: Imagine I have to shape the MB canal of mandibular molar. The length of the canal is 18mm. However, glide path has been prepared only till 16mm. Now when I start instrumenting the canal with my rotary file and when it enters the unnegotiated part, the tip of the file gets locked while the rest of the file keeps rotating which causes separation of that file. This type of failure can happen with a new rotary file also. Fatigue: It is related to overuse of the file. When a file shapes a particular canal, a part of the file is in tension and the other part is in compression. This can lead to building up of fatigue in the metal and its consequent overuse will cause separation of the file. Manufacturers have made remarkable efforts in reducing the fatigue failure by making the NiTi instruments more martensitic in nature by subjecting them to heat treatment. So even though the martensitic heat treated NiTi instruments separate lesser than the conventional NiTi, it does not mean that the instruments can be used countless number of times or that they can be used with the wrong technique without breakage. The latest heat-treated files are a boon to endodontics and we should surely use it to our advantage with proper knowledge and technique. Walia HM, Brantley WA, Gerstein H. An initial investigation of the bending and torsional properties of Ni-tinol root canal files. J Endod. 1988;14:346-351. Parashos P, Gordon I, Messer H H. Factors influencing defects of rotary nickel-titanium endodontic instruments after clinical use. J Endod 2004; 30: 722–725 Arens F C, Hoen M M, Steiman H R, Dietz G C. Evaluation of single-use rotary nickel-titanium instruments. J Endod 2003; 29: 664–666. Zuolo M L, Walton R E. Instrument deterioration with usage: nickel-titanium versus stainless steel. Quintessence Int 1997; 28: 397–402. Ankrum M T, Hartwell G R, Truitt J E. K3 Endo, ProTaper and Profile systems: breakage and distortion in severely curved root canals of extracted teeth. Int Endod J 2004; 30: 234–237. 35. Yared G M, Bou Dagher F E, Machtou P. Cyclic fatigue of Profile rotary instrument after clinical use. Int Endod J 2000; 33: 204–207.

A well-shaped and cleaned canal that is three dimensionally filled is every dentists` dream. A perfect mastercone xray and an overshooting guttapercha cone seen in the same case post obturation is a pain point for most of us. Literature doesn’t tell us how much of extruded GP will cause pain. A minor extrusion can cause tremendous pain whereas a 3mm extrusion might be asymptomatic. Having a good apical tugback can help to avoid this problem. Every canal has a different apical diameter. We use GPs that are standardized but these cones have a tolerance of ±0.05 mm. Clinically, if we have shaped a canal with 35/06 there is a possibility that the apical diameter of the cone might be between 0.30mm to 0.40mm. So, there is a possibility that the tugback might be false and is actually present in the coronal or middle third. When we place the spreader to perform lateral condensation the GP gets pushed beyond the apical foramen. Check out the image below from an article described by Clifford Ruddle which explains it. A simple way to tackle this situation is to use a 4% GP for every case irrespective of the file taper that we use for shaping. This is applicable to any obturation technique. All the different obturation techniques have been explained in detail in our ENDOFINISHER COURSE. Click here to know more. SYSTEM BASED ENDODONTICS Does Your Gutta Percha Master Cone Fit? Clifford J. Ruddle DENTISTRY TODAY September 2016

A frustrating moment in endodontic treatment is the presence of a ledge. Further instrumentation in panic to negotiate the ledge is going to worsen it further. So the most important factor to help us negotiate a ledge is patience. The most predictable technique to overcome a ledge or bypass any obstruction encountered in the root canal is the modified balanced force technique. In this technique we take new 10/15# K file, take it till working length, give a clockwise turn and pull. Continue this motion till a stage is reached where we have now negotiated the ledge and the file now enters the main canal. A slight apically directed pressure is also recommended for this procedure. However do not start this procedure by precurving the file. Any curving of the file weakens it and can cause separation of the file. Use of EDTA helps in advancing the file. A practice that is most commonly performed by many dentists is to give a dressing of viscous EDTA in anticipation that the EDTA will dissolve the ledge and create an open path. However, this doesn’t resolve the issue of a ledge.

Mechanical instrumentation plays a vital role in eliminating bacteria from the root canal. Any rotary instrumentation is always preceded by glide path preparation with manual files. Both types of files have to be instrumented till the anatomic working length. However any instrumentation beyond this working length is going to violate the periradicular tissues. An immediate effect of this is sudden bleeding from the root canal. This iatrogenic complication if not tackled can lead to post-operative flare up. The best way to tackle this complication is to prevent it from occurring. So knowing the working length before starting with rotary instrumentation is mandatory. Once we have initiated the instrumentation, it is necessary that we have a controlled movement of the rotary handpiece inside the canal. If such a complication occurs it is necessary to place calcium hydroxide for the symptoms to resolve.

Almost every other case we treat in our clinic needs an endodontic treatment. Few cases turn necrotic and the bacterial flora invades the periodontium and very often we see a periapical lesion. Such cases require placement of an intracanal medicament. Calcium hydroxide has been the material of choice for many years. However it has been shown to weaken the root structure which can lead to fracture1. In retreatment, one feature that may enable E. faecalis to persist in the root canal is the ability for it to survive conventional antimicrobial agents used during endodontic treatment, such as the alkaline pH of calcium hydroxide. E. faecalis is known to withstand a high pH; indeed, this is an identifying characteristic of E. faecalis. 2,3. Antibiotic paste was developed by Hoshino et al. When developed its applications were mainly related to regenerative endodontics. However, its application to other areas has shown promising results, too. A major advantage is the delivery of the drug directly to the infected site ie the apical foramen and periradicular tissues. AndreasenJO Long-term calcium hydroxide as a root canal dressing may increase risk of root fracture Dental Traumatology 2002; 18: 134–137 Devriese L, Collins M, Wirth R (1992) The Genus Enterococcus. In: The Prokaryotes. A Handbook on the Biology of Bacteria:Ecophysiology, Isolation, Identification, Applications, 2nd edn, pp. 1465–81. New York, USA: Springer-Verlag. Mundt J (1986) Enterococci. In: Bergey’s Manual of Systematic Bacteriology, Vol. 2, pp. 1063–5. Baltimore, USA: Williams & Wilkins.

Caries is a disease that leads to destruction of the tooth. Our role has always been to eliminate the disease and make teeth healthy. This is done either by doing a composite restoration or a root canal treatment depending on the case. In either case it is utmost important that we preserve the healthy tooth structure without compromising on elimination of disease. Restorative dentistry has come up big in recent years due to the advancements in materials and techniques and also due to better understanding of the tooth and dental material interaction. The most important is the phenomenal bond strength of composite to the enamel. During caries excavation, it is important that we preserve as much healthy enamel as possible. But unsupported enamel has to be removed. Endodontic treatment has become more predictable now more than ever and more teeth are being retained. Just like preserving enamel is most important in restorative dentistry, preserving dentin is important in endodontics. Removal of diseased pulp tissue requires shaping of the canal with tapered files. Though these files remove most of the diseased pulp, they also lead to excessive removal of dentin which ultimately lead to reduction of strength. Therefore it is necessary we always give a second thought when we are removing any tissue from the canal. The effect of access cavities and canal enlargement on biomechanics of endodontically treated teeth: a finite element analysis JOE VOLUME 46, ISSUE 10, P1501-1507