micro-surgical endodontics. the state of the art. c the state of... · 2016. 1. 18. ·...

CMicro-Surgical Endodontics. The state of the art.

Pag. 2 Pag. 3

Introduction

By Surgical Endodontics one refers to that branch of Dentistry that is con-cerned with the diagnosis and treatment of lesions of endodontic origin that do not respond to conventional endodontic therapy or that cannot be treated by conventional Endodontic therapy. The scope of Surgical Endodontics is to achieve the three dimensional cle-aning, shaping and obturation of the apical portion of the root canal system which is not treatable via an access cavity, but only accessable via a surgi-cal flap (Fig. 1).For this reason it is preferable to use the term Surgical Endodontics rather than Endodontic Surgery, in as much as the procedure should be planned and carried out as an endodontic procedure via surgical access and not a surgical procedure done for endodontic reasons.Once a diagnosis of Endodontic failure has been made, it is necessary to understand what the cause of the failure was so that successively the possi-bility of correcting the failure by orthograde retreatment can be evaluated. Only in the case where this possibilità does not exist or better still after failure of the non-surgical therapy carried out to resolve the problem, only then is one authorized to intervene surgically.

Micro-Surgical Endodontics. The state of the art.


Apical Surgery in other words is not a substitute for incomplete debride-ment and poor endodontics (Fig. 2). In agreement with what Nygaard-Ostby and Schilder 10 confirmed, Surgical Endodontics must be reserved for those cases in which the preparation and obturation of the root canal appear impossible right from the beginning or when the non-surgical retre-atment attempts have failed. Nevertheless, even in such cases, the authors recommend filling as much of the root canal by conventional method as possible. Currently the technique and instruments for clinical retreatment of endo-dontic failures are so refined that the cases that for certain have to be tre-ated surgically because they cannot be retreated by orthograde means are becoming fewer. Often a high level of Surgical Endodontics experience masks the operators inability to carry out a correct cleaning, shaping and three dimentional ob-turation of the root canal system by non-surgical means.

Fig. 1. A typical example of Surgical Endodontics.

A. Pre-operative radiograph. B. There are two sinus tracts present.

C. Post operative radiograph: the main and the lateral canals were retreated surgically.

D. Two year recall.

Fig. 2. A typical example of Endodontic Surgery: the procedure was carried out after failure of a poorly executed orthograde therapy. A. Preoperative radiograph. B. Postoperative radiograph after orthograde retreatment. C. After a few months the patient presen-ted with a fistula: now there is an indication for surgical retreatment. D. Postoperative radiographs: Super EBA was used as a retrofilling mate-rial. E. Two year recall.

1a

1b 1c 1d

Arnaldo Castellucci MD, DDS

2a 2c2b

2d 2e

Pag. 4 Pag. 5

Ultimately even after the indication for surgery has been established, in agreement with Weine and Gerstein,19 it is recommended to remove as much as possible of the inadequate preceeding canal obturation material and replace it with well compacted gutta-percha: in this way lateral canals, forgotten additional canals can be filled, often removing the need for sur-gery (Fig 3). Nevertheless, in those cases which still have the indication for surgery it is currently possible to have a notably increased percentage of success with the treatment of surgical cases compared with what could be attained up untill a few years ago, and this is thanks to recent technological progress that has happened in the field of Surgical Endodontics. In the last 10-15 years two important developments have been introduced in surgical endodontics: the ultrasonic root end preparation and the surgical operating microscope.

The ultrasonic preparation

For many years the root end has been surgically prepared drilling a class 1 preparation into the dentin, using a straight slow-speed handpiece or a so called “miniature” contra-angle handpiece (Fig. 4) with small round or inverted-cone carbide burs. This approach had many disadvan-tages, mainly the impossibility to create a preparation in the longitu-dinal axis of the root canal and to clean the buccal surface of the root end. (Fig. 5)Trying to give enough retention to the cavity, the risk of a palatal or lingual perforation was always pre-sent and the procedure was more and more difficult as the root canal was more and more difficult to re-ach from the operator. (Fig. 6)The smallest burs were always too big compared with the diameter of the root canals and the big cavities were therefore more difficult to seal. For the same reason, retro-preparations often failed to include isthmus areas.(Fig. 7)The introduction of the ultrasonic root end preparation made pos-sible to obtain what is defined as the ideal retropreparation: a class 1 preparation at least 3 mm into the root dentin with walls parallel to an coincident with the anatomic outli-ne of the pulpal space.1,3.

Fig. 3. A. Due to presence of material beyond the

apex and the closeness of the preceeding root canal obturation to the bifurcation, there could

be an indication for surgical retreatment. B. Orthograde retreatment was carried out which brought to light the presence of two

missed canals, the distobuccal and the mesio-medial canal.

C. The five year recall shows the complete he-aling of the lesion and complete disappearance of the extruded apical material, confirming that a “foreign body reaction” is an excuse invented

by someone who advocates to stay short just because does not want to and does not know

how to prepare canals in their entire length.

3a

3c

3b

Dr. Arnaldo Castellucci graduated in Medicine at the University of Florence in 1973 and he specialized in Dentistry at the same University in 1977. From 1978 to 1980 he attended the Continuing Education Courses on Endodontics at Boston University School of Graduate Dentistry and in 1980 he spent four months in the Endodontic Department of Prof. Herbert Schilder. Since then, he has a limited practice on Endodon-tics. He is Past President of the Italian Endodontic Society S.I.E., Active Member of the European Society of Endodontology E.S.E., Active Member of the American Association of Endodontists A.A.E., Active Member of the Italian Society of Restorative Dentistry S.I.D.O.C. He has been the President of the International Federation of Endodontic Associations I.F.E.A. in 1990-92. From 1983 to 2000 he has been Professor of Endodontics at the University of Siena Dental School. Now is Visiting Professor of Endodontics at the University of Florence

Dental School.In the year 2009 has bee nominated Honorary Professor of the State Higher Educational Estabilishment of Ukraina “Ukrai-nian Medical Dental Academy”. He translated into Italian the text on “Clinical and Surgical Endodontics. Concepts in Practice”, by Frank, Glick, Simon and Abou-Rass. He is the Editor of “The Italian Endodontic Journal” and of “The Endodon-tic Informer”. He is also the Founder and President of the “Warm Gutta-Percha Study Club”. He published articles on Endodontics in the most prestigious Endodontic Journals. He is the author of the text “Endodonzia”, which now is available in the English language. Interna-tional lecturer, he is also Founder and President of the Micro-Endodontic Training Center in Florence, where he teaches and gives hands-on courses on the use of the Microscope in nonsurgical and surgical Endodontics in both languages, Italian and English.

Fig. 4. The smallest contra-angle handpiece is too big compared to the ultrasonic retro-tip.


Fig. 5. SEM image of a retro-preparation made

with a bur. The cavità doesn’t include the buccal aspect of the original canal

(Courtesy of Dr. Gary Carr, San Diego).

Fig. 6. A. The original canal (up) and the retro-preparation (down) made at the expences of the palatal side of the original canal. B. The original canal. C. The cavity has been made with a round bur working in a palatal direction.

Fig. 7. A. The preope-rative radiograph shows a failing retrofill in an up-per first premolar. B. The two canals had been obtu-rated separately and the isthmus hadbeen missed. C. The isthmus has been adequa-tely prepared and sealed. D. Two year recall.

7a

6a 6b 6c

7b

7c 7d

Pag. 6 Pag. 7

In order to do this, special ultraso-nic tips were developed to enable the clinician to reach every root in all clinical situations. The use of the specifically desig-ned retrotips allows the operator to clean the root canal from an apical approach, leaving clean dentinal walls not only on the lingual or palatal side, but also on the buccal aspect, which was impossible to clean with the previous techniques. The cavity now can be made 3 mm deep, without the necessity of ma-king undercuts, since there is no need of further retention. The retrotips are of the same size or even smaller compared to the original size of the root canal, so that the retropreparation can be ea-sily and predictably sealed in the maximum respect of the original anatomy.

The isthmus area can now be inclu-ded into the preparation, without damaging or weakening the root, while being extremely conservati-ve in the mesio-distal dimension.

The surgical operating microscope

The introduction of the surgical operating microscope (Fig. 8) re-presents the other important deve-lopment in surgical endodontics.2,12

For many years periapical surgery has been performed without any magnification, using the dental light as the only light source to illumina-te the surgical field. No surprise therefore if until recen-tely the success rate after surgery was much lower compared to non-surgical endodontics.4 To increase visibility, surgical telescopes or lo-ops and surgical headlamps became available. Loops are available in a variety of configurations and magnifications, starting from 2x up to 6x, with Ga-lileian optics or prismatic optics. When a fiberoptic headlamp is ad-ded to the loops, a coaxial light is projected into the surgical field, so that both magnification and illumi-nation are enhanced.On the other hand, how much ma-gnification is enough? Clinicians who have benefited from the use of loops and headlamps soon understand the limitations of this system. Magnification of 6x sooner or later is not enough anymore and the headlamp is not capable to send the light deep into the canal in sur-

gical and nonsurgical endodontics.The right answer to the previous question is: “enough to see and sol-ve the problem”. The surgical operating microscope has a range of magnifications from 2.5x to 25x and the illumination is coaxial with the line of sight.The coaxial illumination has two advantages: a) the clinician can look into the surgical field without any shadows (which means that it is possible to examine the cleanli-ness of the retropreparation during surgical endodontics); b) since the coaxial illumination is made possi-ble because the operating microsco-pe uses Galileian optics, and since Galileian optics focus at infinity and send parallel beams of light to each eye, the operator’s eyes are also fo-cusing at infinity and every proce-dure can be performed without any eye fatigue.As far as the magnification is con-cerned, there is no need to go be-yond 20-25x. Lower and medium magnifications are used for opera-ting; higher magnifications are used only for observing fine details.


Fig. 9. Working at small magnification it is possibile to visualize the entire operative field.

Fig. 10. During a surgical procedure in a lower quadrant it is necessary to localize the mental nerve to avoid any kind of damage to this important anatomical structure. The photograph has been taken through the operating microscope at minimum magnification.

9 10

Working at high magnifications me-ans to have a very limited depth of field and limited illumination, and therefore is not practical l.2.The use of the surgical operating microscope has several advantages in surgical endodontics:a) better visualization of the surgi-cal field;b) better evaluation of the surgical technique;c) better accuracy during the entire procedure;d) better predictability of long term results.For these reasons, the author is fir-mly convinced that surgical endo-dontics should not be performed without the use of the microscope, from the injection of anesthesia to the removal of sutures.Under the microscope, the incision made with the microsurgical scalpel is more accurate, with less trauma to the soft tissue, a more passive flap elevation and later reapproximation is semplified. At minimum magnifi-cation, the entire surgical field can be observed (Fig. 9, looking for the mental nerve (Fig.10), for instance.

Fig. 8. The surgical operating microscope allows a more ergonomia and com-fortable working position.

Pag. 8 Pag. 9

The size of the osteotomy is usually small (usually less than 5 mm), big enough to accomodate the ultraso-nic tips, which have a tip length of 3 mm. (Fig. 11) Working at 10x to 20x magnifica-tions, the small osteotomy allows a perfect control of the entire surgical procedure.

Microsurgical technique

Anesthesia

In surgical endodontics the goals in anesthesia are to provide profound anesthesia not only for the procedu-re, but also for a prolonged period

of time following the surgery and also to provide a good hemosta-sis.1 For this purpose, the anesthe-sia of choise is 2% lidocaine with 1:50.000 epinephrine. (Fig. 12)Other anesthetic solutions with less epinephrine are contraindicated, be-cause the eccessive bleeding of the surgical site will compromise surgi-cal visibility. The slow administration of anes-thetic solution with 1:50.000 epine-phrine has no contraindication even in medically compromised patients. The use of the microscope during the administration of the anesthetic solution is helpful to avoid the in-jection near bigger capillary vessels and can guarantee almost no blee-ding once the needle is removed.

Incision

Using microsurgical scalpel blades (Fig. 13) under the microscope even at minimum magnification, the sur-geon can make a very precise inci-sion with minimum damage to the soft tissue. If enough attached gengiva is pre-sent, the mucogengival incision is preferable, in order to preserve the existing epithelial attachment. If there is limited attached gengi-va or if there are short roots or lar-ge periapical lesions or when the cervical aspect of the root must be examined because for instance a vertical root fracture is suspected, the flap of choice is the triangular or rectangular flap with sulcular in-cision. In both flaps, the elevation must be undermined (Fig. 14), to

reduce the trauma to the soft tissue: the elevation begins at the vertical releasing incision and continues to the coronal margins in an apical-coronal direction. The mucogengival incision is scal-loped, to facilitate reapproximation, but it is not beveled, like it used to be years ago. As a matter of fact, the incision once was suggested to be beveled to avoid scars. Recent researchers 1 and the use of the operating microscope have de-monstrated that the incision made at 90° to the bone below (Fig. 15) allows a much more precise reposi-tioning and suturing of the flap and consequently a better healing by primary intention, with absolutely no scar tissue formation. On the other hand, the beveled in-cision could cause the surgical flap to slip, with consequent wrong re-positioning and healing by seconda-ry intention, which is the only true cause of scar tissue.


Osteotomy

With a round surgical bur mounted on a high speed handpiece (Fig. 16) and under copious irrigation with saline solution the surgeon starts the removal of bone to isolate the root apex. If the cortical plate has been perfo-rated by the lesion, the location of the root apex is very easy and the removal of bone is minimum. If the cortical plate is still intact, the gentle removal continues until a dif-ference in color is appreciated: the yellowish dentin can be easily reco-gnized against the white bone. The osteotomy must be large enou-gh to provide good visibility and to allow the use of all necessary instruments: curettes, retrotips, mi-cropluggers. Once the root apex is identified, the lesion is removed completely to provide a better control of the blee-ding and later a faster healing.

Fig. 11. The bony crypt should

be large enough to allow the introduction of the

ultrasonic tips.

Fig. 16 Surgical round burs for high speed (up) and fissure burs (bottom).

Fig. 12. The use of anesthetic solution with vasocon-strictor 1:50.000 is the “conditio sine qua non” to perform the surgical procedure

Fig. 13. Comparison of BP #15C blade to a CK2 micro-

surgical blade (CK Dental).

Fig. 13. A-C. The microsurgical blade is making a sub-marginal flap, and is undermining flap elevation using Ruddle 30° curette in order not to damage the periostium.

Fig. 15. The sub-marginal flap should be made using the blade at 90° to the underlying tissue.

13a 13b 13c

Pag. 10 Pag. 11

The complete removal of the lesion is contraindicated if the aggressive curettage could endanger anatomic structures, such as mental or mandi-bular nerve, maxillary sinus or floor of the nose or the blood supply of adjacent vital teeth. It is well known that healing of le-sions of endodontic origin proceeds only after the removal of contami-nants from the root canal system and not just removing the inflamed tissue surgically 1.

Apical resection

The apical resection is made using a Lindemann bone-cutting bur (Fig. 17) on a high speed handpiece spe-cifically designed for oral surgery

(Fig. 18): it has no air out-put to eliminate the danger of air emboli-sm and the bur is mounted at a 45° angle to enhance visibility under the microscope, especially in posterior teeth. The apical resection is made almost perpendicular to the long axis of the root (Fig. 19) and must be complete both in bucco-lingual and in mesio-distal directions.1, 6 The microscope is very helpful in locating the root canal, to evaluate the presence of multiple portals of exit, to locate and then eliminate the extruded fil-ling material and the old and failing amalgam retrograde, the apical root fracture, and the accessory canals on the root surface. The best way to inspect the surface of the beve-led root is using a small amount of methylene blue dye (Fig. 20).It will be a lot easier to verify that the root has been completely sectio-ned, that an isthmus is present, and

if a vertical root fracture is present (Figs. 21, 22).

Bleeding control

It is imperative that the retrofilling procedure is made in a dry field. For this purpose, the bleeding inside the bony crypt must be totally eli-minated and totally under control. The dental assistant uses a small suction tip and follows the entire procedure using the assistant scope. She will help to maintain a dry field

and a good visibility for the surge-on. If the suction is not enough to keep the blood away from the be-veled root surface, a few drops of anesthetic solution with 1:50.000 epinephrine are placed on a sterile gauze and then pushed against the walls of the bony crypt for a few minutes. Another more efficient method to completely eliminate the bleeding from inside the crypt is the use of ferric sulfate, which causes instantly a very good haemostasis, having an extremely low pH (0.21)


Fig. 19 A, B. The root is sectioned almost

with a 90° angle.

Fig. 18 The surgical handpiece Impact Air 45 (Star Dental, Lancaster, PA, USA) enhances efficiency, safety and vision and prevents the risk of air embolism.

Fig. 17 Lindemann bone cutting bur,mounted on the Impact Air 45 surgical handpiece.

Fig. 20 The methylene blue (Vista Dental, Racine, WI, USA) is used to visualize an apical vertical root fracture.

19a

19b

Fig. 21A-C. The apical vertical root fracture is now evident.

Fig. 22 Same case of fig. 21. A. Pre-operative radiograph. The upper right first premolar has a separated instrument in the palatal root and an overfilling of gutta-percha next to the buccal root. During the surgical procedure it was evident that the extrusion of gutta-percha happened through the apical verti-cal root fracture that was caused by the lateral condensation technique. B. Post-operative radiograph. C. Two year recall. If the apical root fracture can be eliminated during the beveling of the root structure, the prognosis remains excellent.

21a 21b 21c

Pag. 12 Pag. 13

and causing rapid intravascular coa-gulation (Fig. 23). The use of ferric sulfate has no contraindications, but it must not be used in contact with important anatomic structures, like mandibular or mental nerve, maxil-lary sinus or floor of the nose. Its use is also to be avoided on the cor-tical bone and on soft tissues. When the retrofilling procedure is com-pleted and before suturing, it is also imperative to completely remove it in order to avoid a delay in the hea-ling process 8, 9 and for this purpose a curette under copious irrigation is used in order to stimulate the blee-ding.

Apical retropreparation

A large variety of retrotips are today available to make what has been de-fined as the ideal retropreparation. Several ultrasonic units specifically designed for root end preparation are also commercially available. The first retrotips introduced into the market were designed by Gary Carr3 and were available in different sizes, the standard CT Tips (Fig. 24) and the smaller SLIM JIM tips (Fig. 25). A special tip to work in roots with a very pronounced lingual in-clination is the Back Action Tip, de-signed by Gary Carr (Fig. 26). Re-cently, Syngcuk Kim designed new tips made in stainless steel coated with zirconium nitride. They are called KiS Microsurgi-cal Ultrasonic Instruments (Obtura Spartan) and ProUltra (Dentsply,

and then activated. The tips should penetrate the old filling material without resistance. They should be activated only when inside the root canal and then deactivated before their removal from the root canal. This is done to avoid a scratch or any kind of damage to the surface of the root bevel. The removal of the previous failing amalgam retrofill is also facilitated

Tulsa Dental) (Fig. 27a) and they have several advantage:a) they are more aggressive and cut dentin fasterb) the irrigation port has been pla-ced near the working tip, with incre-ased efficiency and more abundant irrigation during the retroprepara-tion (Fig. 27b)c) they are slightly longer than other retrotips, for better access to areas difficult to reach.Retrotips coated with diamond are also available, like the ones desig-ned by Elio Berutti (Fig. 28).Very useful are also the retrotips designed by Bertrand Khayat BK3, with three bends specifically made to reach areas of difficult approach (Fig. 29).The retrotips should be placed per-pendicular to the root surface and parallel to the long axis (Fig. 30)


Fig. 24Carr Tips angled at 90° (CT1, CT5) and 70° (back action).

Fig. 25Carr Tips “Slim Jim” #1 and #5.

Fig. 27A. The ProUltra Microsurgical Ultrasonic Tips designed by Clif-ford Ruddle. B. Note the irrigation port very close to the working tip.

Fig. 26The Back Action tip is indicated in roots with a very pronounced lingual inclination, like the upper lateral incisor.

Fig. 28The retrotips designed by Elio Berutti are diamond coated (EMS).

Fig. 29The retrotips BK3 desig-ned by Bertrand Khayat

(Satelec) have three bends specifically made to work easily in posterior teeth.

Fig. 30The ultrasonic tip should

be positioned first and then should be activated.

Fig. 23 A. The ferric sulfate is used to control the bleeding in the bony crypt. B. The needle has a little brush, to gently paint the bony crypt with the solution.

23a

23b 27b

27a

Pag. 14 Pag. 15

by the use of the retrotips which many times can remove the old filling in one single piece, without risk of tatoo. If the root to be treated has two or more canals, the surgeon must be very careful and look for the isthmus, which contains pulp tissue and debris as any other en-dodontic space and therefore must be cleaned and included into the re-tropreparation (Fig. 31). Failure to prepare and seal the isthmus is an invitation for failure (Fig. 32). The isthmus sometimes can be so narrow that it is difficult to see even under the microscope. There fore, as a general rule, in all roots with multiple canals the isth-

mus must always be prepared,1 even though we cannot see it with the mi-croscope!Once the ultrasonic preparation is completed, it is examined for com-pleteness. If debry are still present, the surgeon can use again the re-trotip, irrigate and reexamine the retropreparation. The cavity should be 3 mm deep (Fig. 33) and the walls completely free of the old gutta-percha or sealer (Fig. 34). The operating microscope is crucial to examine the accuracy of the re-tropreparation and this is done with the use of the micromirror (Fig. 35) after the cavity has been irrigated with saline solution and dried with

a light flow of air using the Stropko surgical irrigator15 (Fig. 36).

Root end filling materials

Historically, amalgam has been the retrofilling material of choice for many years, but today it is not used anymore since it has several disad-vantages, like corrosion, expansion, and leakage. The most widely ac-cepted retrofilling materials today are zinc oxide-eugenol cements, like IRM and Super EBA, 11 and Mineral Trioxide Aggragate (ProRoot MTA Dentsply Tulsa Dental)18. The zinc oxide-eugenol cements are easy to manipulate, have adequate working time, dimensionally stable, sufficiently biocompatible, bacte-riostatic, radiopaque, don’t discolor the tooth or the surrounding tissues and are easy to remove. The Super EBA cement is mixed to a putty consistency, shaped into a narrow cone, attached to the end of a spo-on excavator or a little spatula and carried to the apical preparation 13

(Fig. 37). The cone of material reaches the base of the preparation while the sides of the cone contact the walls. Between each aliquot of material, a pre-fitted plugger is used to conden-se the Super EBA. The material is condensed in excess on the beveled surface of the root using a ball burnisher. When the cement has set, a finishing bur is used to finish the retrofilling. The integrity of Super EBA is then examined at high magnification af-ter the surface has been dried with

the Stropko irrigator. A post-operative radiograph is now exposed and then the surgeon is re-ady to suture the flap.As already stated, zinc oxide-euge-nol cements are easy to manipulate but at the same time the have seve-ral disadvantages, first of all they are affected by moisture18.On the other hand, it is well known and universally accepted that iso-lation of the operative field for the moisture control is a challenge in dentistry in general and in endodon-tics in particular. In non-surgical endodontics, the root canal system must be absolutely dry in order to achieve a good apical seal and any contamination with blood must be avoided. In the same way, during a direct pulp capping as well as du-ring a perforation repair the hemor-rhage must be kept under control, and of course also in surgical en-dodontics during the retrofilling the cavity must be completely dry.As an alternative to ZOE cements, a new material has been recently introduced in endodontic surgery as a retrofilling materia 14,16-18 (Fig. 38). Mineral Trioxide Aggregate (MTA) is a powder consisting of fine hydrophilic particles of trical-cium silicate, tricalcium aluminate, tricalcium oxide and silicate oxide. It also contains small amounts of other mineral oxides, which modify its chemical and physical properties and make the material radiopaque. Hydration of the powder results in a colloidal gel that solidifies to a hard structure in approximately three hours.


Fig. 31Stereo-microscopic view of the retropreparation made in an extracted third molar: the isthmus has been incorporated into the retropreparation, with the maximum respect of the root canal anatomy.

Fig. 32A. This retrofil failed because the isthmus was missed. Note also how the two amalgam retrofils have almost nothing to do with the original loca-tion of the two root canals. B. Same tooth at higher magnifications (Courtesy of Dr. Gary Carr, San Diego).

Fig. 33The ultrasonic root end preparation must be at least 3mm deep and within the long axis of the root canal.

Fig. 34The ultrasonic root-end preparation of the mesio-buccal root of an upper molar. The preparation has included the two canals and the isthmus.

Fig. 36Utilizing the Stropko irrigator, a precise, control-led stream of air can be directed into the root-end preparation and effectively enhance vision and dry the cavity.

Fig. 37The tapered end of the SuperEBA roll is attached to the end of a little spatola and is being positio-ned inside the retroprep.

Fig. 38The white ProRoot MTA (Dentsply Tulsa Dental, OK).

Fig. 35EIE miniature retromirrors. The more often used are the oval (3x6 mm) and the round (3 mm) (Courtesy of Dr. Gary Carr, San Diego).

32a

32b

Pag. 16 Pag. 17

This cement is different from other materials currently in use because of its biocompatibility, antibacterial properties, marginal adaptation and sealing properties, but more than everything for its hydrophilic natu-re17. Materials used to seal the retro-preparation in surgical endodontics are inevitably in contact with blood and other tissue fluids. Moisture may be an important fac-tor due to its potential effects on the physical properties and sealing abi-lity of the restorative materials.16 As shown by Torabinejad et al,16 MTA is the only material that is not affected by moisture or blood con-tamination: the presence or absence or blood seems not to affect the se-aling ability of the Mineral Trioxide Aggregate. In fact, MTA sets only in the presen-ce of water.17 Having said that, the MTA is consi-dered today the material of choice for direct pulp capping, 17 to close

open apices,17 to repair perforations 17 and to seal the retropreparations in Surgical Endodontics.MTA has several advantages:a) easy to mix and place into the ca-vity with a small carrierb) since it sets in the presence of moisture, it is not moisture sensitive and is not affected by blood conta-minationc) seals better than amalgam, Super EBA or IRMd) has a better adaptation to the sor-rounding dentine) has excellent biocompatibilityf) activates cementogenesis (Figs. 39, 40).A disadvantage of the material is that it is not easy to handle and when it was first introduced to the market, there was no appropriate carrier to position it during different applications.The first carrier that became availa-ble was the Dovgan Carrier (Qua-lity Aspirators) (Fig. 41), but even

though the needles were bendable, its use was not comfortable during surgery.In the year 2000 another carrier was proposed by Edward Lee,7 but its use was limited to surgery (Figs. 42,43).Recently, another carrier has been designed and manufactured by Pro-duits Dentaires SA (Switzerland) in cooperation with Dr. Bernd Il-genstein, 5 called The MAP (Micro Apical Placement) System (Fig. 44) and this can be considered an “uni-versal” carrier, since it has special needles that can be used both in

clinical and in surgical endodontics and during surgery allows an easy positioning of MTA also in poste-rior teeth.

Instrument

The system consists of a stainless steel applicator, with a bayonet catch (Fig. 45) for several exchan-geable applicators cannulas (need-les). The straight and curved nee-dles (Fig. 46) are for non-surgical endodontics, while the triple angled (Fig. 47), developed in cooperation with Dr. Bernd Ilgenstein, and sin-


Fig. 39A. Post-operative radiograph. The retrofil has been made using white MTA. B. Two year recall. Note the perfect healing.

Fig. 41Dovgan carriera (Quality Aspirators).

Fig. 42The carrier described by Dr. Edward Lee.

Fig. 43The pre-measured aliquot of MTA is easily deli-vered into the root-end preparation (Courtesy of John Stropko, Phoenix, AZ).

Fig. 44The Micro Apical Placement (MAP) System (Produits Dentaires SA, Switzerland).

Fig. 46The straight needles for nonsurgical endodontics.

Fig. 45The bayonet catch for connecting

the exchangeable needles.Fig. 40A. Pre-operative

radiograph. B. Post-operative

radiograph. The retrofil has been made

using grey MTA. C. Two year recall.

Note the perfect healing.

39a

39b

40a 40b 40c

Pag. 18 Pag. 19

gle angle (Fig. 48) needles are best indicated for surgical endodontics.The surgical needles are available in two variants, right-angled and left-angled, each with two external diameters, 0,9 mm (yellow) and 1,1 mm (red). The internal diameter of the cannulas is 0,6 mm (yellow) and 0,8 mm (red), which allows for suf-ficient portions of the retro-filling material to be applied successively.The filling material can be taken from a dispenser/well (Fig. 49). The intra-cannular plungers of the angled needles are made of PEEK (Polyether Ether-Ketone), a poly-mer used for medical purposes (Fig. 50), and the plungers of the straight and curved needles are made of NiTi (Fig. 51).

Residues of material in inside the cannulas can be easily removed with a cleaning curette (Fig. 52a,b).It is well known that since the ul-trasonic tips have been introduced into the market, the root surface is no more cut with a bevel at 45°, but rather with an almost 90° angle (Fig. 19b). This involves the need of a specific carrier in order to deliver the retro-filling material at a 90° angle (Fig.

53a-e). The MAP System is the perfect car-rier for this purpose, having several needles in different sizes and with different angulations.The single angle needles are best in-dicated for anterior teeth while the triple angle needles are best indica-ted for posterior teeth. They are available in two variants, right-angled and left-angled, for an easier treatment of hard-to-reach re-

gions (palatal canals of upper pre-molars and molars, lingual canals of lower molars).The intra-cannular plunger inside the needle is intentionally longer than the needle itself (Fig. 54), so that it will not only deliver the MTA in the retro-preparation, but will also act as a plugger and thus begin to compact the material in the dee-pest portion of the prepared cavity (Fig. 55a-e). The risk of air bubbles


Fig. 47The triple-angle needle for surgical endodontics in posterior teeth.

Fig. 53A-E. The pre-fitted needle is carrying the filling material.

Fig. 54The intra-cannular plunger inside the needle is inten-

tionally longer than the needle itself.

Fig. 48The single-angle needle for surgical endodontics in anterior teeth.

Fig. 50The intra-cannular plunger of the angled needles is made of PEEK.

Fig. 51The intra-cannular plunger of the straight needles is made of NiTi.

Fig. 52A. Cleaning curettes of

different sizes. B. The tip at higher

magnification.

Fig. 49Dispenser for filling material.

52a

53a

53c

53e

53b

53d

52b

Pag. 20 Pag. 21

can therefore be avoided. As a re-sult, the retrograde root canal filling will always be well compacted.Another advantage of using the MAP System during surgery is the perfect control of the obturating material, which will be laid in the retro-cavity without any dispersion in the surrounding bone and soft tis-sue.Once the retro-cavity has been pre-pared using the ultrasonic retro-tips and the bleeding of the bony crypt is under control, the operator asks the dental assistant to mix the MTA to the correct consistency and then to handle the pre-fitted applicator syringe. The consistency of MTA must be neither too wet nor too dry. If the mix is too wet, it will be diffi-cult to compact the material into the cavity properly. If it is too dry, it will be difficult to extrude the material from the needle and the syringe can remain blocked.

Should the latter be the case, it is essential to avoid pushing too hard. The PEEK plunger is insufficiently rigid and will remain bent next to the bayonet catch, and thus needs to be replaced. For this reason, is al-ways advisable to have two needles ready for use.

Suture

Suturing under the operating micro-scope has the advantage of being more accurate in repositioning the flap, allowing a perfect healing by primary intention, without any scar tissue. The author disagrees with people who recommend the use of the microscope for osteotomy, cu-rettage, apicectomy, apical prepa-ration, retrofilling and documenta-tion but not for the incision as well as for suturing. Suturing under the microscope can be difficult someti-mes, especially in posterior regions,

but the accuracy in reapproximation provided by the microscope cannot be compared with that provided by the use of loops or, even worst, by naked eyes.Ideally, the suture must keep the soft tissue in place during the time of healing and should not encoura-ge colonization of bacteria. If re-positioning has been accurate as it should be, healing occurs by prima-ry intention in 24-48 hours and this is the reason why suture removal is indicated after 24-48 hours.1 When left in place for a longer period of time, the suture has no function and is simply an irritant: soon it will be completely covered by bacteria and will cause inflammation and dela-yed healing by secondary intention.Many suture materials are commer-cially available today. Silk is not recommended anymore because it encourages colonization by bacte-ria. Nylon is colonized more slow-ly, but is too rigid and often patients complain because the suture is irri-tating the lip or the cheek. Tevdek is a newly introduced suture made of a polytetrafluoroethylene impregna-ted polyester material. It is very re-sistant to bacterial colonization and

is nonirritating. The suggested size of the suture is 6-0 (Figs. 56-58).

Conclusion

Endodontic surgery can today be performed with an accuracy and predictability of results that were not possible to reach 10 or 15 years ago. Magnification and illumination together with the new instruments and materials provide a higher suc-cess rate than ever before (Fig. 59). Using the microscope, the incision is more accurate, the elevation of the flap is less traumatizing for the soft tissues, the osteotomy and the apicectomy are more conservative. Using the ultrasonic tips the retro-preparation is more precise, coaxial with the root canal, the entire circu-mference is cleaner, the retro-fill is also more accurate, and the exact repositioning of the soft tissue gua-rantees a perfect healing without any scar. For all these reasons, the surgical procedure is more predictable and the success rate is very high.

Fig. 55A-E. The carrier also functions as a plugger, beginning to compact the filling material in the deepest portions of the prepared cavity.

55a

55b

55c 55d

57a

57b

55e

Fig. 56Tevdek 6-0 polyester suture (CK Dental Specialties).

Fig. 58In this other case, the patient could not come back for suture removal before the fifth day afterv surgery was completed. Note the complete absence of plaque around the Tevdek suture.

Fig. 59A. Pre-operative radiograph. B. Two year recall. Note the retrofil three mm deep, within the long axis of the root canal, and of the same size like the original root canal.

Fig. 57A. The Luebke-Ochsenbein flap has been sutured with 6-0 Tevdek. B. Three year recall: complete absence of scarring.


Pag. 22


1. Carr, G.B., Bentkover, S.K.: Surgical Endodontics. In: Co-hen S. and Burns R.C. Eds. Pathways of the Pulp 7th ed. St. Louis, USA: Mosby, 1998: 608-656.

2. Carr, G.B.: Microscopes in Endodontics. Calif. Dent. Assoc. J. 11:55-61, 1992.

3. Carr, G.B.: Ultrasonic Root End Preparation. In: Kim S. ed. The Dental Clinics of North America. Microscopes in Endodontics. Philadelphia, USA. W.B. Saunders Company Vol. 41, N° 3, July 1997: 541-554.

4. Frank, A.L. et al.: Long-term evaluation of surgically placed amalgam fillings. J. Endod. 18:391-398, 1992.

5. Ilgenstein, B., Jager, K.: Micro Apical Placement System (MAPS). A new instrument for retrograde root canal fil-ling. Schweiz Monatsschr Zahnmed, Vol. 116: 1243-1252, 12/2006.

6. Kim S.: Principles of Endodontic Microsurgery. In: Kim S. ed. The Dental Clinics of North America. Microscopes in Endodontics. Philadelphia, USA. W.B. Saunders Company Vol. 41, N° 3, July 1997: 481-498.

7. Lee, E.S.: A new Mineral Trioxide Aggregate root-end fil-ling technique J. Endod. 26:764, 2000.

8. Lemon, R.R., Jeansonne, B.G., Boggs, W.S.: Ferric sulfate hemostasis: effect on osseous wound healing. II. With curet-tage and irrigant. J. Endod. 19:174-176, 1993.9. Lemon, R.R., Steele, P.J., Jeansonne, B.G.: Ferric sulfate he-mostasis: effect on osseous wound healing. I. Left in situ for maximum exposure. J. Endod. 19:170-173, 1993.

10. Nygaard-Ostby, B., Schilder, H.: Inflammation and infec-tion of the pulp and periapical tissues: a synthesis. Oral Surg. 34:498, 1972.

11. Oynick, J., Oynick, T.: A study of a new material for retro-grade fillings. J. Endod. 4:203-206, 1978.

12. Rubinstein, R.A.: The anatomy of the surgical operating microscope and operating positions. In: Kim S. ed. The Den-tal Clinics of North America. Microscopes in Endodontics. Philadelphia, USA. W.B. Saunders Company Vol. 41, N° 3, July 1997:391-414.

13. Rubinstein, R.A.: Endodontic microsurgery and the sur-gical operating microscope. Compendium. (18) 7:659-672, 1997.

14. Schwartz, R.S. et al.: Mineral trioxide aggregate: a new material for endodontics. Case reports. J. Am. Dent. Assoc. 130:967-975, 1999.

15. Stropko, J.J.: Apical microsurgery. Endodontic communi-qué. Boston University, School of Dental Medicine, Summer 1998, 12-14.

16. Torabinejad, M., Higa, R.K., McKendry, D.J., Pitt Ford, T.R.: Dye leakage of four root end filling materials: effects of blo-od contamination. J. Endod. 20:159-163, 1994.

17. Torabinejad, M., Hong, C.U., McDonald, F., Pitt Ford, T.R.:Physical and chemical properties of a new root-end fil-ling material. J. Endod. 21:349-353, 1995.

18. Torabinejad, M., Watson, T.F., Pitt Ford, T.R.: Sealing ability of a mineral trioxide aggregate when used as a root end filling material. J. Endod. 19:591-598, 1993.

19.Weine, F.S., Gerstein, H.: Periapical Surgery. In Weine F.S.: Endodontic Therapy. 3a ed. St. Louis.

Bibliography

Via Degli Artisti, 6/r Firenze - Italy, 50132TEl. +39 055 5001312 - Fax+39 055 5000232www.endocastellucci.it [email protected]

micro-surgical endodontics. the state of the art. c the state of... · 2016. 1. 18. ·...

Documents