1 hour molar endo

8/7/2019 1 Hour Molar Endo

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1 Hour Molar Endo

Molar endo in less that 1 hour using conventional

instruments and without instrument breakage issues

Richard Erickson, MS, DDS

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Volume 17; 2007

Excerpted Article e-mail: [email protected]

"CUTTING EDGEINFORMATIONFORTHEDENTAL PROFESSIONAL "

200 SEMINARSAND 30 JOURNALS REVIEWED YEARLYFORTHE LATEST, CUTTING EDGE INFORMATION

Dental Updatesental Updatesental Updates

2007, DCIDental CareersTM

, All Rights Reserved.Incorporated


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for anterior teeth. Tay hasrecently reported19 that tetracy-cline from Bio Pure remainingin the dentin of anterior teethmay become oxidized overtime, resulting in iatrogenictetracycline staining of thetooth. This may be prevent-able, according to Tay, bypre-rinsing the tooth withascorbic acid solution whichwill prevent the oxidation ofthe tetracycline. Bio Pure mayneed a wait-and-see from clinicians before using routinely inpractice.

Still Think the Canal Filling Material Matters?

In a recent issue (Vol. 14, pg. 9), we reported on a review ofthe factors contributing to the successful clinical outcome forendo treatment. In that review, it was noted that the quality of thefinal restoration was paramount over the quality of the completed

root canal treatment. A new study on how quickly bacteriapenetrate through any root canal filling material shows howimportant this final restoration really is.

Yucel, et al, tested the bacterial penetration of canals filledwith the following materials: AH Plus, AH 26, Sealapex andKetac-Endo. Bacterial colonies were harbored at the sealed canalorifice and were judged to have penetrated the canal when theycould be cultured at the apex. After 30 days, 75% of the speci-mens were penetrated. After 60 days, 100% of the specimens hadbeen penetrated. So much for our futile efforts at sealing canals.The real endodontic treatment begins with the final restoration.

Molar Endo in One Hour or Less:

Because of continued requests for our one hour (often less)molar endo technique which first appeared in Vol. 2 of DentalUpdates, we are rerunning the article here. I have updated thetechnique and materials as necessary but it remains basicallyunchanged. While many dentists are doing engine-driven NiTifile endodontics, file separation continues to be an issue and anuncomfortable one at that for the practitioner and the patient. Forthat reason and the fact that this method is nearly as fast butwithout the concerns of file breakage, I have continued to preferthis technique over NiTi.

With this technique, you can complete most molar endo inone hour or less (3 canal, first molars frequently take 45 minutes)and anterior teeth can be completed in 20 minutes. Why wouldyou want to refer out this easy, one appointment, no lab fee treat-ment? The patient will never complain about the shade or theesthetics of endo. Its a practice builder of the first order.

Studies of Resilon-type (EpiphanyTM) filling materials havenot conclusively shown that the seal and quality of fill is betterthan achieved with gutta percha. Much of the research isauthored by names with a commercial interest in it, which tendsto cloud the credibility of the data.

While the warm gutta percha technique (Buchanan) has proponents, simple lateral condensation is perfectly adequate asfilling technique, especially since all research shows that it is tcoronal seal (restoration) which determines the ultimate succeor failure of the endo treatment. All, repeat ALL canal sealisystems currently on the market have been shown to leak bacterto the apex within 30 days if exposed to oral fluids. Thereforeremains essential to permanently seal the canal orifice area wian appropriate restorative material.

I feel there are two primary reasons some general dentisprefer to send out this highly profitable procedure. One is visibity, they cant see into the pulp chamber and must rely on toucto find the canals, a very stressful technique. The second is tdifficulty in accurate measurement of the working length andifficulty in obtaining this measurement with xrays, even digitThese stressful impediments to endo treatment are addressed #in the materials and equipment list below. The materials aequipment you must have to perform this one hour molar endprocedure are:

1. Magnification, Apex Locator, Headlight: These three item

are #1 because if you dont have them, theres NO REASOto go any further with this technique. The three absoluteessential things needed for fast, easy, high quality endodontreatment are: Magnification-preferably 3.5X or higheFiber-optic headlight; and a high quality, dual circuit aplocator. Without this equipment you will be in the dargroping your way by touch alone, doing endo like you had in dental school which everyone hated. You would agrthat if you can see a crown margin, a good prep is possiblWhy should it be any different with endo? The only way ocan visually see the canals (including the frequently prese4th canals in molars) is with magnification and illuminatio

There is NO need to purchase a microscope for quality en

unless you want to learn separated instrument retrieval.

We have talked about Apex Locators in past issues and theis no debate any longer as to their accuracy and reliabilitThere are probably a half dozen good, dual circuit aplocators on the market. The two I am familiar with and haused are the Root ZX (J Morita) and the Endex (Osada). TRoot ZX seems to be the industry standard. You cannot rapid, easy endo if you have to stop and take measuremexrays. Period.

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2. Medidenta 1500: This instrument has been around for a longtime (see photo below). It is a sonic filing system which usesits own proprietary files called Shapersonic and Rispisonic.The Rispisonic files are too aggressive and can strip open acanal if one is not careful. The shapersonic files are lessaggressive and suited to the purpose of flushing out debris.You will only need size #15 and #20 shapersonic files(25mm) for this technique.

3. Clorox Full Strength and RC Prep: While many newerirrigation products have come on the market, nothing is aseffective for dissolving tissue AND killing bacteria as 5%sodium hypochlorite, PERIOD. RC Prep is useful tolubricate the hand files to prevent ledging and to work past

ledging should it occur.

4. Extended Working Time (EWT) Sealer: (Sybron-Kerr)Many now are using AH-26 which is a resin type sealer. Idont have any experience with AH-26 but it has favorableliterature research.

5. K-Flex files:(Sybron- Kerr) Yes,theyre about a zillionyears old but they work!They cut dentin, theyreflexible and they almostnever break, even afterunwinding abuse.K-Flex files differ fromregular files in that theblank is rhomboidshaped, not square like a regular file, thus has sharper cuttingflutes. If you like using Barry Musikants Safesider files,theyre fine too. Your choice. Recently CRA evaluated theEDS engine driven endo system which uses reciprocalSafeSider files in a reciprocating handpiece. While no fileseparations were reported using this system, only 62% of theevaluators stated that this system was superior to the one theycurrently use20.

6. Gates Glidden drills: You will use only the #2-4 to actuallyenter the canal, #5&6 may be used to widen the orifice ifdesired for ease of instrument or filling material entry.Never, repeat NEVER use a #1 Gates Glidden in a canalunless you want instrument separation at the head.

7. Miscellaneous: Long shank, latch-type #2-4 round burs forunroofing the pulp chamber in molars. Safe tippeddisposable irrigation syringes. Gutta percha points (ISOsized) and Fine sized gutta percha points.

Over the years of doing endo (including 2nd molars), I hahad the occasion to hear numerous speakers and have tried mansystems. This is the technique that works best for me. It isstraight forward gutta percha technique with some "high tecand will have your post op xrays looking as good as the speciaists!

Evaluation and Diagnosis

Molar endo is no more difficult than anterior, albeit a littmore time consuming. If the patient is moderately to severeswollen and/or in extreme pain, we medicate for several days relieve the symptoms. Amoxicillin 500mg tid is the usual choibut some recommend clindamycin as being more effective. If tsigns and symptoms are less than obvious as to which tooth is tculprit, then a series of tests are in order. Evaluation of xrays aelectronic pulp testing is universally known and won't discussed here.

Other tests such as tapping on the facial aspect of varioteeth with a mirror handle, having the patient bite on a "toosleuth", as well as hot and cold testing, will usually identify tcorrect tooth. An inexpensive way to cold test is to buy a can oComponent Cooler from Radio Shack and spray it on a cottotip applicator. Applying it to suspect teeth in a quadrant usuaunmistakably identifies the culprit. Most healthy teeth wmomentarily react painfully to this ultra cold stimulus, howevean abscessing tooth will be excruciatingly painful and/or the pawill linger beyond when the tooth returns to mouth temperature.

Evaluation of the patient and the involved tooth should occnext. Can the patient open wide enough to maneuver a standalength endo file into the tooth? Can canals and pulp chamber seen on the xray? If the answer is no to either question, I geneally refer the case. Theres no point in struggling when there aso many easy cases out there.

Access Opening

After anesthesia and rubber dam placement, adjust the blength by holding the handpiece with a330 bur against a bite wing xray so thatthe flat chuck surface is even with thecusp tips and the tip of the bur justpenetrates the pulp chamber (see illus-tration at right). The big fear is aperforation. However, if you use thistechnique and follow the long axis ofthe tooth, it is almost impossible sincethe head of the handpiece prevents you

from going too deep.

Again, looking at the bitewing xray (the least distorted of xrays), see if the pulp chamber liesdirectly below the confines of the molarcusps, and if so, then you need to staywithin these landmarks. I always open allpulp chambers (anterior and posterior)with a 330 bur. It gives you control,visibility and very little bur chatter on the

tooth. Another trick is to flatten theocclusal surface (photo right) of molars

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with a C&B diamond about 2mm IF you are going to crown thetooth afterward. This will give you better visibility and accessinto the pulp chamber.

Crowns, especially poorlyanatomical PFMs, present some diffi-culty in locating the pulp chamberwithout perforation. For this reason aswell as avoiding repairing the hole

afterward, I recommend removal of thecrown, if possible, using an Almore(Richwil) crown removal jelly bean(1-800-547-1511). Once the crown isremoved, the position of the pulp chamber is much better visual-ized.

With tipped teeth, it is often difficult to visualize the properangle of penetration to the pulp chamber. These cases are themost frequently perforated by the inexperienced clinician,however it need not be so. In these cases, DO NOT apply therubber dam until access to the pulp chamber has been realized.The rubber dam often masks and distorts the long axis of the

tooth, especially if it has been crowned with a PFM. There is noneed at this point for the rubber dam and its role in asepsis andpreventing aspiration. Once pulpal access has been gained byvisualizing the tooth in its natural state, the rubber dam is appliedand further exploration with files can begin.

After opening into the pulp chamber, you may want toremove the entire roof with the 330 or elect to use a low speed #4or #6 round bur. Extend the opening so that you have a straight,vertical access to the entrance of the canals. The biggest mistakeinexperienced practitioners make is having too small of an accessopening. I will sometimes use a tapered C&B diamond to smoothand taper the access opening toward the occlusal on molars.Next, fill the pulp chamber with a few drops of full strength

Clorox. Using a #10 or #15 K-flex file and an endo explorer,locate all canals and insure that there is patency to the apex.Estimate the working length of the canal using a pre-op xray.Flush the canals for 10-15 seconds with the Medidenta 1500

(800-221-0750) (photo below), lots of water, and a #15 shaper-sonic file, again estimating the length with a PA xray. NOTE: the#15 shapersonic file will not ledge the canal if you are short, sodon't worry about it and if you're a little long, that won't hurt

either. NOTE: if you BEND the tip of the #15 shapersonictrying to find the canal, discard it!! The tip will break off in

the canal if you straighten it and try to use it (ask me how I

know).

If you suspect intact nerve tissue in any of the canals, insert aFINE broach into the canal, do a quarter turn to engage the tissueand remove the nerve tissue in one piece. If this is not donebefore instrumentation, compacted nerve tissue may block out theapical 1/3 of the canal and make it very, very difficult to penetrateto the apex (See Blocked Out, below).

Instrumentation of the Canals

You now need to widen the upper half of the canals wi

Gates Glidden drills. NOTE: never use a #1 Gates Glidden any canal as they fracture easily at the head! Always begin with#2 and be sure the pulp chamber is filled with full strenghypochlorite (Clorox) which acts as a lubricant, disinfectant, aalso digests tissue in the lateral canals. With the #2 GatGlidden, try to negotiate it about half way down the canal. Ne

do the same with #3 and #4. Anything larger than a #4 GatGlidden may perforate the root at its concavity so only use the #and #6 to flare the canal orifice.

In between Gates Glidden drill changes, flush and instrume

with the Medidenta 1500 sonic and a #15 shapersonic file. Rit for about 5 to 10 seconds up and down with lots of water sprfrom the 1500. For upper bicuspids especially, the Mediden1500 is excellent at removing the thin, ribbon connection betwethe buccal and lingual canals. Withdrawing the Medidentoward the buccal while in the lingual canal and vice versa wquickly widen the ribbon isthmus and enable you to clean it debris. Debris left in the canals from a cutting instrume

(whether it is a hand file or Gates Glidden drill) will make use the next size slow and difficult. Also, ledging of the canals ainstrument breakage occurs more easily if debris remains in tcanals. After flaring the canal orifice with the #6, you are reato measure with the electronic apex locators. The electronic apfinders and the 1500 sonic handpiece are the key pieces of equiment which make it possible to do molar endo in under an hourhave heard many nationally recognized endodontic speakeremark on the incredible accuracy of the current generation

apex locators. Two that I have used extensively are the End(Osada; 800-426-7232) and the Root ZX (J. Morita; 888-90

3636; www.jmorita.com). The Osada and the Root ZX do nuse the "resistance method" employed by the less expensi

brands or the early models from years ago. Rather, they usedual-frequency reference comparison method which can operaaccurately in wet, dry, hypochlorite filled, necrotic, or bloocanals.

Numerous research studies have confirmed the accuracy these apex locators. Several published studies were done teeth to be extracted and compared radiographic measuremenagainst those from apex locators. The results showed that whneither method was 100% accurate, these apex finders weaccurate more often and had the least error with regard to the trapex as opposed to the radiographic apex which is often beyothe true apex.

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The xrays at the leftare of endodontic proce-dures on teeth #19, 31 and3 done in our office. Onlythe apex locator was usedto determine workinglength, no measurementxrays were taken. Tooth#19 had an existing metalcrown which was left inplace making the electronicmeasurements more diffi-cult. In cases like these,you need to blow out theexcess hypochlorite fromthe pulp chamber toprevent conductance fromthe canal to the crown, andavoid touching the metalcrown with the file as it isadvanced toward the apex.Note the sealant "fins" inthe lateral canals of #3.

Over the years, I havebecome so confident in theaccuracy of the apexlocators, I rarely take ameasurement xray exceptfor the final to check thegutta percha fill. When the

instrument is not capable of giving a true reading, you will knowit by the erratic reaction of the dial readout.

Use a small file for all measurements (#15 or #20) as these

seem to give the most consistent results and yes, these apexlocators (AL) work well in the presence of blood, Clorox, localanesthetic or whatever else is in there. If the reading is a littleerratic or squirrelly, try using a larger file as studies21 haveshown that the largest file which can reach the apex will oftengive the most accurate reading. When the AL "shorts out" orbecomes erratic, it is usually due to conducting fluid contacting alarge MOD amalgam which then shorts to the PDL. It can alsooccur when the root is fractured. Touching the file to the metal ofa PFM or gold crown will do the same thing so stay clear of thatwhile inserting for measurement. If you accidentally contact themetal edge, the needle indicator will become erratic but you needonly to get back to the center of the access opening to continueyour measurement. For large MOD amalgams, do not have thepulp chamber wet with anything, blow it bone dry just prior tomeasurement. It is OK, however, to have some conducting fluidin the canals, as long as it does not complete the circuit to theamalgam and PDL. Follow the instructions with the instrumentand you will become proficient at rapid measurement and confi-dent of its accuracy.

OPTIONAL: A very accurate check of the measurement canoften be made using a "fine" or "extra fine" paper point (Bucha-nan). If the apical foramen is patent, insert the paper point towhere it is 1-2mm beyond the apex and remove. If there is blood

at the tip of the paper point, the exact length of the canal can found by measuring the distance between the point where tblood stops and where the paper point was grasped by cottpliers at the landmark reference. Buchanan reports there is "wicking" up the paper point and that the blood at the tip coveonly that which extended beyond the apical foramen.

Once measurement of all canals is obtained, instrumentatican begin. Start with the sonic 1500 and a #15 shapersonic f

and measure the file exactly to the working length. Insert into tcanal and with copious water spray from the handpiece, move t1500 up and down to the working length until it moves smooth(about 5 - 10 seconds). If the #15 shapersonic will not mofreely to the working length, use a #15 or #20 hand file until ycan. Now you can begin hand filing.

Hand filing brings to mind tedious, finger numbing denschool nightmares. This is not like that at all. Because the upphalf of the canal has been widened with the Gates Glidde(crown down technique), the hand files work only in the apic1/3 of the root and only take seconds per file.

If the #15 shapersonic file has done its job, you can usual

begin hand filing with a #20 file (K-Flex files). With a couple quick "watch winding" strokes, you should be able to go to tfull working length easily. Go back with the #15 shapersonic athe 1500 to remove the debris (full length). The few secondstakes to flush the canal with the Medidenta is extremeimportant. The next larger file will go easily to the workilength with a little watch winding if ALL the debris has beremoved from the last file. Next, squirt a little hypochlorite inthe pulp chamber and/or canals and use the #25 K-Flex in similar fashion as before. Repeat with the #15 shapersonic remove the debris (lots of water). The #15 shapersonic is flexible and gentle, it does not seem to ever ledge a canal and tdebris removal surpasses anything else I know of. On straig

canals or gently curving ones, a #20 shapersonic file can be usebut nothing larger or you will ledge and make the case very difcult from that point forward. Remember, the sonic irrigation for debris removal, NOT to enlarge the canal.

N.B.:Always lubricate each hand file with RC Prep befo

using. This will keep you from becoming blocked out.

This back and forth alternation between #15 shapersonirrigation and increasing size hand files goes quickly up to #30 #35 in curved molar canals since constrictions in the upper half the canal have been removed with the Gates Gliddens. Once thand filing with the K-Flex to the working length becomes difcult, you should stop at that number. Molar canals are usua

finished to #35, sometimes #40 to full working length. Occasioally I have stopped at a #25 on narrow canals. If you cannreach the apex with the next hand file, sonic irrigate and go bato the last smaller size and re-instrument to the working length.

One last step needs to be done, insure patency of the apicforamen. You do not want a debris plug filling the foram(Buchanan). Measure a #10 hand file 1-2mm longer than tworking length and insert up to the measurement stopper. Ycan usually "feel" it go through the apical foramen. By doithis step, you will see a small puff of sealer cement beyond tapex on the post-op xray (it gives those macrophages somethin

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to do!!). As Drs. Ruddle and Buchanan state, "Cases don't faildue to slight overfill of gutta percha."

A note on engine driven nickel - titanium files or hand ni-tifiles. I have tried them and they don't (in my hands) increase thespeed or quality of the end result. In addition, there are breakageproblems with Ni-Ti instrumentation which have not been solvedby the manufacturers. Engine driven Ni-Ti systems are verytechnique sensitive and file breakage within the curved canal is a

problem -- I did it on my first case!! If you: (1) push the rotatingfile too hard, (2) linger too long within a curved canal or (3) usethe file once too often, breakage occurs. Then you have to tell thepatient, "We've decided to put a high tech titanium plug in theroot canal instead of the old fashioned rubber stuff." So until thesystem becomes more idiot proof, I prefer to stick with thismethod.

A note on irrigants during shaping and filing procedures.Some say that disinfectant irrigants (Clorox) are unnecessary andthat ordinary water works fine, especially when using the 1500sonic instrument. The 1500's sonic waves are very effective atflushing debris out of canals. However, in order to dissolve

tissue and bacteria in the lateral canals, only full strength (5%)Clorox is effective. In order to dissolve the tissue in the lateralcanals, Buchanan states that Clorox must sit in the canals for aminimum of 30 minutes. You can see the "digestion" of tissuewithin the canal by the frothing bubbles. Replenishment of irrig-ant should occur every 5 minutes and can be done by the assistantwhile the doctor is doing something else. I frankly have not beenable to sit idly for 30 minutes during a RCT and have notfollowed this rule. I have used the 1500's sonic vibration (#15shapersonic) with Clorox to speed up tissue digestion. Hereshow to do it. Turn the water spray on the Medidenta OFF.Holding the Medidenta in my right hand, I insert the tip of theClorox irrigating syringe into the pulp chamber ONLY. With the

Clorox flowing slowly, I activate the Medidenta. Now you havesonically agitated, slightly warmed Clorox, digesting tissue inlateral canals as nothing else can.

Gutta Percha Fill

I won't go into the details of fitting the master cone as this isbasic Endo 101, but suffice it to say, I do like a small amount of"tug back". Once all the master cones are fitted and laid out so asto be clear which goes where in multi rooted teeth, mixing of

sealer can begin. We have been using Extended Working TimeSealer (EWT) by Kerr/Sybron (photo left) for many years andit performs very well. It must be the powder / liquid kind as the

"tube" kind sets too quickly. It

is extremely slow to set whichis what you want. There aresome brands (TubliSeal &Sealapex - Kerr) on the marketwhich seem to be fine untilthey contact a little moisturewhich causes them to setquickly and prevents their flowinto lateral canals. It is hardnot to have some moisturefrom humidity within the tooth.

The cement is mixed to the consistency of syruThoroughly dry all the canals with paper points followed by asyringe drying.

The master gutta percha point is test fitted then coated libeally with cement. It is placed in the canal and pumped up adown about a half dozen times to work the cement throughout tcanal. The gutta percha is removed, re-coated and "pumped"few more times. On the final pump, run the gutta percha to

"seat" position at the apex. Lateral condensation using "fingutta percha points and spreaders is done until canal is filleEach gutta percha point is coated with cement before placing the canal.

Next, heat the tip of a small spoon or endo plugger withbutane torch to melt off the excess gutta percha down to the canorifice. Re-heat the instrument several times until the smamount of gutta percha within the pulp chamber and the top 3mof the canal is softened. Using a warm endo plugger, somewhsmaller than the orifice to the canal, firmly compress the softenegutta percha and sealer mass into the canal several times unwell compacted. Sealer applied to the plugger beforehand w

keep the gutta percha from sticking to it. Compressing tsoftened gutta percha & sealer with the plugger, will force thsealer into lateral canals and slightly out the apex. You will thsee the desired little "puffs" of cement in the PDL on the post-xray. Apply Cavit as a temporary to close the access opening atake the final xray. You will note that even when finishing uthe EWT sealer has not begun to set which is what you want.

Summary

1. Open to pulp chamber (330 bur) and extend for verticstraight line access to all canals.

2. Insure patency of all canals to estimated working length wi#10 or #15 file. Using #15 shapersonic with lots of watemove the instrument in an up and down or circular motio(10-15 seconds) to enlarge canals slightly. Estimate lengwith undistorted PA xray. You won't ledge the canal wthe #15 if you're short so don't worry. Use a fine or exfine broach if you suspect intact nerve tissue within thcanals.

3. Gates Glidden canals to #4 (do NOT use the #1!!!) about hway down root and widen orifice with #5 and #6. BetweGates Glidden drill changes, flush with #15 shapersonic alots of water spray.

4. Blow out excess water from pulp chamber and using the #or #15 file together with the apex finder, measure tworking length. Until you gain confidence with tinstrument, you may want to check it with an xray.

5. At this point, you can usually begin filing (watch windimotion) with a #20 to the working length, then #25, #30, #3hand files. Always irrigate and flush between files with t#15 shapersonic, blow dry and refill canals and pulp chambwith full strength Clorox for next file. If the canals are ntoo curved, a #20 shapersonic can be used instead of a #1However, a #25 shapersonic will almost certainly ledge

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curved canal which means you're cooked!!! Curved molarcanals can usually be instrumented to working length to a#30-35 K-Flex file. I have sometimes stopped at a #25because of constricted resistance. Remember to alwayslubricate each file with RC Prep which is easy to do if youuse the Jordco EndoRing (see below)

6. Dry with paper points, air, and test fit the master gutta percha

(MGP).

7. Mix the cement (EWT Sealer; Kerr Sybron) (not runny, nottoo thick), coat the MGP and pump up and down in the canalto force the cement out the lateral canals and the apex. Seatthe MGP.

8. Using spreader and "fine" gutta percha, continue with lateralcondensation. Coat each gutta percha with sealer beforeplacing.

9. Heat sear off the excess, soften the remaining GP in the pulpchamber and within the canal.

10. Using an endo plugger, firmly compress the softened GPmass and sealer into the canal until well filled. Pre-coatingthe plugger with sealer will keep the GP from sticking to it.

11. Temp with Cavit, take final xray. Give yourself a pat on the

back.

12. Finally, buy an EndoRingTM

kit (Jordco - $75) to helporganize files and GatesGlidden drills. It has a

convenient ring-fingerholder, a well for EDTA(RC Prep) and an endoruler. It's a real time saverand totally autoclavable.

Baring complications, tighttortuous canals, etc., an upper or lower molar endo should be ableto be completed (finished) in under an hour. I recently completedan endo procedure on #29 (I know it's an easy tooth) AND acrown prep on #3 in 45 minutes total. My assistants did take thefinal endo xray and made the temporary crown for me afterward.Tooth #30 was recently completed in our office in 45 minutes

using this technique.

If you can see a visible pulp chamber and visible, moderatelycurved canals on the xray, it should be a piece of cake tocomplete molar endo in one hour or less with a minimum ofhassle. Endo can be relaxing if you use the equipment describedin this section. I am less stressed doing endo than crown andbridge. Remember, you must have magnification AND highintensity illumination. If you can SEE it, you can DO it.

ThermaFil Filling Technique

Many recommend using the ThermaFil technique for fillithe canal with a preheated, softened, gutta percha coated carrieThe carrier can be a plastic post or metal file similar in size anshape to that of an endodontic file.

I began to use this technique when it first became popular balways had mixed results. Perhaps you have had similar expe

ences. On some post-op xrays, the canals looked well filled wisome sealer/gutta percha expressed out the apex and/or latercanals. On others, however, the post-op xray looked as if just tcarrier (the metal file) was occupying the lower of the canwith all the gutta percha stripped off.

I was perplexed for an explanation until a research articdiscussed this technique and the problem of "back pressureWhen the salespeople demonstrate the technique at meetings, italways done with a Lucite block replica of a canal with the apexiting the Lucite block at the side or bottom. Thus, when tThermaFil carrier is pushed into the canal entrance, the trappair exits out the lateral and apical ports, and the plasticized gutpercha is carried in a continuous wave ahead of the carrier to thapex. Much of the research was carried out on extracted teewhich allowed the same thing to happen. In real life, in vihowever, the air cannot escape a tooth surrounded by periodotium. Back pressure builds up which can strip the gutta percfrom the carrier. Thus, by the time the carrier reaches the apeno gutta percha remains, giving a denuded look to the carrion the post-op xray and resulting in an unacceptable apical seal.

A article by Lee22, et al, studied in vitro the effects of striping of gutta percha from Thermafil carriers. Dye penetratiinto the apical portion of the completed root canal was signifcantly higher than that of those done using a conventional latercondensation technique. These are the factors which preclude m

use of this technique.

Overcoming Blocked Out Problems

Instrumenting too aggressively, not removing debadequately with irrigation and/or the Medidenta 1500, ancompacting residual nerve tissue at the apex can all result being blocked out. Becoming blocked out occurs whobstructions within the canal, usually at the apical 1/3, prevent attempts to instrument beyond the blockage point. The clinicimay then elect to fill to the point of blockage and hope for thbest. It need not be so, blockages can be penetrated and trement continued to the proper resolution.

Several things are needed to overcome blockages: very smafiles, RC Prep, and full strength Clorox. Files no larger than #should be used in the attempt to penetrate the blockagsometimes files as small as #6 or #8 are used. Particularly usefare the Schewd C type (extra stiff) #6 and #files(www.schwed.com/pg2.html#ant). All files used in the effoto penetrate the blockage must be pre-bent as shown here withvery small radius curve at the tip so as to prevent ledging of thcanal. The canal should be loaded with RC Prep (use the file carry it into the canal)and a few drops of fullstrength Clorox. With

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22 Lee: Gen Dent, 1998; 46(4): 378


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firm but gentle watch-winding motion, the small files areworked into the blockage. Remove the file frequently, inspect thetip for deformation, re-bend if necessary and reload with moreRC Prep.

It may take 5-15 minutes of careful work but the blockagewill eventually be cleared. Further instrumentation with largerfiles can then commence. Remember, the best way to preventblocking out is to lubricate each file with RC Prep before

inserting it into the canal. The reservoir on the EndoRingTM isparticularly useful for keeping the RC Prep handy.

Separated Instruments

As I mentioned, the above methods most noteworthy benefitis the lack of separated instruments. In over 20 years of doingendo -using K-Flex (Kerr) files, I have had only one separate.That file was over used and its separation was iatrogenic. Unfor-tunately, it could not be retrieved so it was bypassed as can oftenbe done using the technique below. Attempting to bypass aseparated instrument is probably the least invasive of all themethods used to resolve this issue. Many experts recommendthat this should be tried first.

The technique for this has been discussed in previous issuesbut is basically the same as that for working through a blockout mentioned above. Only #6 or #8 extra stiff carbide Ctype files should be used with copious amounts of RC Prep. Thefiles should be pre-curved slightly prior to use. Once the fileworks its way past the separated piece, take an xray for confirma-tion that you are within the canal. Carefully enlarge the canal toa #25 and fill.

Hiding the PFM Access Hole

Your patients new PFM molar or bicuspid crown needs anendo and you're dreading the "dark hole" composite filling. Ive

seen a zillion composite plugs in PFMs and they all look like crapbecause no composite is opaque enough to block out the DARKinterior of the PFM. No need to fret, this tip will make theserepairs INVISIBLE.

First remove all temporary filling material and cotton plugfrom the access opening. I like to begin my composite build-up-restoration at the canal orifices. Next, use H-F porcelain etchingfor 2-4 minutes on the band of porcelain, rinse and dry. Now etchand bond all interior surfaces using your favorite total-etch orself-etch system. I prefer to use SE Bond or Liner Bond 2V

(Kurarary) because of itsexcellent porcelain bond

activator, which in myview, produces the strong-est porcelain to compositebond on the market. Infact, Reality reportedthat it even exceeded theexperimental control.

Line the deepest partsof the cavity with your

favorite flowable acure, thin layer pleasBegin to fill the deepeparts of the cavity wiany shade of gocomposite (A), using 2mincrements, be sure acondense to remove voidContinue filling acuring until you are with4mm of the cavo-surfamargin. Next, flow inthin layer (1-2mm) Pentron's flowabUniversal Opaque

Pentrons UniversOpaquer is the only oneknow of that is opaqenough for this task. Uan explorer if necessary push the opaquer (B) up

cover the metal core line but NOT the porcelain (don't obsess you get a smidgen on it, however). Cure the opaquer and applysecond and third layer if necessary to block out ALL the darkneand metal. Finally, fill the remainder of the cavity with any go

posterior composite of the appropriate shade (C). The before aafter photos shown here have not been retouched -- it looks thgood ! Plus, your patient will be convinced their crown "undamaged".

Local Anesthesia:

Nasal Spray?

Researchers at the University of Buffalo dental school23 ha

been experimenting with a local anesthetic nasal spray. Principinvestigator, Dr. Sebastian Ciancio stated, It may mean the eof dental injections when performing procedures on the maxillaarch. Testing is currently underway to determine the optimdosage for assuring dental anesthesia.

The idea for this evolved from nasal treatment of patients bENTs using a nasal anesthetic spray. The patients reported ththe spray also numbed their teeth.

Bevel Concerns?

Some practitioners (myself included) believe that turning tbevel away from the ramus insures that any needle deflection w

therefore be toward the bone and thats a good thing. Studiconfirm24 that this is not necessary. Using a 27 Ga needle (1long), there was no difference in success of anesthesia wheththe bevel was turned toward or away from the ramus. Whew, omore piece of baggage I can remove from my anal brain.

The Wand

The Wand is an expensive local anesthetic device whiuses costly disposable materials on each patient. Many swear it but does it help in highly anxious children?

Volume 16; 2007 17

24 Steinkruger G: J Amer Dent Assoc, 2006; 137:1685-91

23 Ciancio S: Univ of Buffalo School of Dentistry, 2007; as reported by R Goldstein in www.dentalxp.com, 2007

Before

After


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mW/cm2

Volume 17; 2007 2

Please Note:

The techniques and procedures in this

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only. Any licensed practitioner reviewing this

material must make his or her own

professional decisions concerning specific

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