|Year : 2015 | Volume
| Issue : 2 | Page : 31-37
Endodontic microsurgery: An overview
Sumangali Ananad1, E Soujanya2, Ananda Raju1, Aravelli Swathi3
1 Department of Conservative Dentistry and Endodontics, Dental College, University of Sebha, Libya
2 Department of Conservative Dentistry and Endodontics, Meghna Institute of Dental Sciences, Nizamabad, Telangana, India
3 Department of Conservative Dentistry and Endodontics, SVS Dental College, Mahbubnagar, Telangana, India
|Date of Web Publication||22-Jun-2015|
Department of Conservative Dentistry and Endodontics, Meghna Institute of Dental Sciences, Nizamabad, Telangana
Source of Support: None, Conflict of Interest: None
The concurrent development of better techniques has resulted in greater understanding of the apical anatomy, greater treatment success, and a more favorable patient response. These developments marked the beginning of the endodontic microsurgery era that began in the 1990s. There is a substantial difference in surgery outcome between those using the microscope and those do not. Use of advanced technology like a microscope, specially designed instruments, improved root end filling materials help to achieve faster wound healing with lesser postoperative complication.
Keywords: Dental operating microscope, illumination, magnification, microsurgery
|How to cite this article:|
Ananad S, Soujanya E, Raju A, Swathi A. Endodontic microsurgery: An overview. Dent Med Res 2015;3:31-7
| Introduction|| |
Endodontic surgery is a facet of comprehensive root canal treatment, which can manage problems that cannot be eliminated by nonsurgical techniques.  The desire to eliminate disease at the root end, the need to obtain a clearer understanding of the complexities of pulpal anatomy, and the use of enhanced magnification and illumination have fathered contemporary apical surgery, more accurately described as apical microsurgery. 
Along with better visualization with microscope, advances in technology including specially designed instruments, improved root end filling materials, and along with a more thorough understanding of the biology of wound healing, have all contributed to the contemporary concept of "Microsurgical Endodontics." 
| Principles of Endodontic Microsurgery|| |
The triad of endodontic microsurgery encompasses magnification, illumination, and instruments. Without any of these elements, microsurgery would not be possible. Illumination and magnification are provided by the surgical operation microscope and have fundamentally changed the way endodontic surgery is performed. With bright, focused light on a × 4 to × 31 magnified surgical site, the surgeon can see every detail of the apical structures and can execute treatment more precisely. As an additional benefit, the magnification has also resulted in smaller osteotomies.
The third element of the triad is instrumentation. Working in a magnified surgical site required a different set of surgical instruments. The standard endodontic surgical instruments are too large for the microsurgical approach. Ultrasonic tips, condensers, pluggers, curettes, and mirrors were reduced in size to comfortably fit into an osteotomy no larger than 5 mm to gain access to the canals.  [Table 1] shows the differences between traditional and microsurgical approaches. ,
| Classification Of Endodontic Microsurgical Cases|| |
Kim and Kratchman  classified periradicular lesions into categories A-F. Lesion Types A, B, and C represent lesions of endodontic origin and are ranked according to increasing size of periradicular radiolucency. Lesion Types D, E, and F represent lesions of combined endodontic-periodontal origin and are ranked according to the magnitude of periradicular breakdown.
Class A represents the absence of a periapical lesion, no mobility, and normal pocket depth, but unresolved symptoms after nonsurgical approaches have been exhausted. Clinical symptoms are the only reason for the surgery.
Class B represents the presence of a small periapical lesion together with clinical symptoms. The tooth has normal periodontal probing depth and no mobility. The teeth in this class are ideal candidates for microsurgery.
Class C teeth have a large periapical lesion progressing coronally, but without periodontal pocket and mobility.
Class D are clinically similar to those in Class C, but have deep periodontal pockets.
Class E teeth have a deep periapical lesion with an endodontic-periodontal communication to the apex but no obvious fracture.
Class F represents a tooth with an apical lesion and complete denudement of the buccal plate but no mobility.
Classes A, B, and C present no significant treatment problems, and the conditions do not adversely affect treatment outcomes. Classes D, E, and F present serious difficulties. 
| Ergonomics and Positioning (Patient/Surgeon)|| |
One of the most frustrating aspects of microscopic surgery is the correct positioning of the dental operating microscope relative to the patient and operative field.  The patient is positioned in a supine to slightly Trendelenberg attitude so that the surgical osteotomy site is most superior in the operating field. This position can vary from the patient simply turning their head to actually laying on their side. The patient can then be stabilized for comfort in this new position using rolled-up surgical towels, "donut" style headrests or memory foam pillows.
The surgeon then takes a position at the head of the patient, the 11-12 O'clock orientation. The operator's chair height is adjusted so that the angle formed between the thigh and lower part of the foot is a minimum of 90°, and the spine is comfortably straight. The patient's chair is then raised or lowered so that the surgeon can maintain his or her elbows close to his body, passively bent at a neutral 90°. Once positioned, the surgeon's arms and hands should not deviate from the core-centric position; this affords the greatest dexterity and precise micro-control while limiting fatigue and strain trembling. The microscope is last positioned with the line of sight axis perpendicular to the soft tissue field of the intended flap, and the binocular eyepieces adjusted to a comfortable height relative to the operator.
Inclinable optics allow for the microscope to assume different vertical attitudes relative to 90°, and a shift of as little as 20° in either direction will enable the surgeon to look past the head of the handpiece to the end of a burr, or use direct vision to examine a resected root end. It is also imperative to have the microscope visual axis parallel to the root long axis at the selected resection level; if the observation position is skewed off-angle, the resection will mimic that angle. 
| Microsurgical Instruments|| |
Traditional surgical instruments are simply too large for working at magnifications of × 10 and × 25. The design and manufacturer of the first generation of micro-instruments are Dr. Garry Carr.
Examination instruments are a mirror, periodontal probe, explorer, and micro explorer. Incision and elevation instruments-15 and 15 C blade, mini scalpels and blades, Periosteals Molt 9, Prichard PPR3, PPB user, P145S, P9HM, P4 elevators. Curettage instruments - mini jacquette 34/35 scaler, a Columbia 13-14, and minimolten and miniendodontic curettes. Inspection Instruments-Micro-Mirrors. Retrofilling carrier and plugging instruments. Miscellaneous instruments are a large ball burnisher and a bone file, microrongeur. Osteotomy instruments - The Impact Air 45 handpiece, The H 161 Lindemann Bone Cutting Bur. Suturing instruments - Laschal microscissors, or any small-beaked scissors, and the castroviejo needle holder. Tissue retraction instruments - Kim-Pecora tissue retractors, Rubinstein retractors, Prichard retractors.
Dental cart - The cart is a compact, all in one unit with the essentials built in. It has a tank for sterilized water (an important feature) high and low-speed handpiece ports, an ultrasonic unit, and a Stropko irrigator/drier. This cart is an important piece of equipment for a modern microsurgery practice.
Ultrasonic units and tips
The three most widely used ultrasonic units are the EMS Miniendo (Analytic Endo), the Spartan (Spartan/Obtura) and the P-5 (Satelec).
Surgical ultrasonic tips, first designed by Dr. Garry Carr are known as Carr tips or CTs. They are 1/4 mm in diameter and about 1/10 the size of a conventional microhead handpiece. The CT 1 and CT 5 have the same design except that the CT 5 tip is more sharply pointed. The hook-shaped tip, known as a back-action or CK tip, is very effective for cleaning the buccal wall of a canal. The CT 1 and CT 5 tips are used mainly for maxillary and mandibular anterior teeth. The CT 2 and CT 3 have a double angle to facilitate work in posterior teeth.
The Kim surgical (KiS) ultrasonic tip is the next generation microsurgical tips. It is coated with zirconium nitride and has an irrigation port near the tip rather than the shaft (as with CTs). The cutting tip is of 3 mm. These advanced tips cut faster and smoother and cause fewer microfractures because of the improved positioning of the irrigation port.
KiS 1 tip: has an 80° angled tip and is of 0.24 mm in diameter, is designed for the mandibular anterior teeth and premolars.
KiS 2 tip: has a wider diameter tip and is designed for wider apex teeth (e.g., maxillary anteriors).
KiS 3 tip: designed for posterior teeth which are hard to reach. It has a double end and a 75 degree angled tip for use in the maxillary left side or the mandibular right side.
KiS 4 tip: similar to the KiS 3 except that the tip is angulated at 110°, to reach the lingual apex of molar roots.
KiS 5 tip: is the counterpart of the KiS 3 for the maxillary right side and the mandibular left side.
KiS 6 tip: counterpart of the KiS 4 tip. ,,
| Case Selection|| |
Failure of previous endodontic therapy, for teeth that have some form of anatomical deviations like tortuous roots, severe S- and C-shaped canals, sharp angle bifurcations, pulp stones, calcifications, and other elements that prevent the complete debridement and subsequent obturation of the root canal system, procedural errors like ledge, block, or perforation of the canals during instrumentation, breakage of instrument inside the canal, overfilling, or underfilling of canal. 
In teeth which are in Proximity to neurovascular bundles, in endodontic-periodontic lesions as periodontal defect always compromises the chances of successful endodontic surgery. Patients with leukemia or neutropenia in the active state; severely diabetic patients; patients who have recently had heart surgery or cancer surgery; and older, ill patients are the rare exceptions. 
| Anesthesia and Hemostasis|| |
For posterior surgeries this entails, for maxillary sites, a posterior superior and middle superior alveolar block; for posterior mandibular sites, an inferior alveolar nerve block supplemented with a mental nerve trunk block. Maxillary anterior teeth are blocked using bilateral anterior superior alveolar or infraorbital injections, while mandibular anterior teeth receive bilateral mental nerve blocks.
Long-acting anesthetic agent such as bupivicaine (Marcaine) should be given to obtain a sustained level of anesthesia beyond the duration of the surgery. Once the regional anesthesia has been achieved, then a local infiltration of lidocaine 1:50,000 epinephrine is injected over the intended flap extent, concentrating the bulk of the infiltration over the surgical site. 
The following sequence is recommended to achieve effective hemostasis during endodontic microsurgery. 
Inject two carpules (maximum three carpules in special situations) of 1:50,000 epinephrine containing local anesthetic, e.g. 2% xylocaine, into multiple infiltration sites buccal/lingual and palatal throughout the entire surgical field.
Place an epinephrine pellet into the bone crypt followed by dry sterile cotton pellets until the crypt is filled. Apply pressure for 2 min, then apply cotton pellet soaked with ferric sulfate solution. All of the ferric sulfate deposits must be carefully and thoroughly removed by a saline flush, as they are a major irritant to the tissues if left in-situ. A large osteotomy site is filled with freshly mixed calcium sulfate paste. Although the paste is not designed for hemostasis per standard error, it is a very effective agent for hemostasis for a large bone crypt.
Moist gauze compresses should be applied to the tissues before and after suturing. 
| Soft Tissue Management|| |
Management of soft tissues also become increasingly important for an esthetically successful treatment. 
New concepts and practice in soft tissue management
The following management procedures have changed from the traditional techniques.
- The semilunar incision, the most popular flap design technique with anterior teeth, is no longer recommended because of inadequate access and scar formation 
- The removal of sutures is done within 48-72 h not a week and
- New suture materials are monofilament, gauge 5 × 0 or 6 × 0 to provide rapid healing ,
- The papilla base incision has been developed to prevent loss of interdental papilla height with sulcular incisions 
- Flap retraction during the surgery is facilitated by making a resting groove in the bone, especially during mandibular posterior surgery to ensure retraction. 
Two simple techniques: interrupted suturing and sling suturing are recommended. Usually the interrupted suture technique is used for the vertical releasing incision, and the sling suture technique is used for the interproximal and sulcular incisions.  More rapid soft tissue healing is a result of reduced tissue trauma and enhanced wound closure during microsurgical procedures. 
| Osteotomy and Apical Root Resection|| |
An osteotomy, which entails the removal of the cortical plate to expose the root end, must be approached deliberately and carefully so that the osteotomy is made exactly onto the apices. The first step is to take radiographs perpendicular to the roots from two different angles with which to ascertain the length of the roots, the curvature of the roots, the position of the apices in relation to the cusp tips and the number of roots. Finally, the proximity of the apices to apices of adjacent teeth, the proximity of the mental foramen, the mandibular nerve, and sinus space can be ascertained. Once the flap has been raised, the mental image of the radiographs should be superimposed onto the cortical plate.
Once the surgeon is sure of the exact location of the apex, the cortical bone is removed slowly and carefully with copious water spray under low magnification ( ×4 to × 6).
The H 161 Lindemann bone cutter and the Impact Air 45 handpiece are best suited for creating an osteotomy. The bone cutter bur is specially designed to remove the bone while minimizing the frictional heat. It has fewer flutes than conventional burs, which results in less clogging and more efficient cutting. The advantage of the Impact Air 45 handpiece is that water is directed along the bur shaft, while air is ejected out of the back of the handpiece. This creates less splatter than conventional handpieces and decreases the chance of emphysema and pyemia. 
The smaller the osteotomy, the faster the healing. For instance, a lesion smaller than 5 mm would take on average 6.4 months, a 6-10 mm size lesion takes 7.25 months and larger than 10 mm requires 11 months to heal. Thus, the osteotomy should be as small as possible, but as large as necessary to accomplish the clinical objective. 
With the microsurgical techniques, the size of the osteotomy is significantly smaller, just 3-4 mm in diameter. This is just larger than the ultrasonic tip of 3 mm in length, yet allows the tip to vibrate freely within the bone cavity. 
Once the lesion and the root tip are exposed, Columbia #13 and #14 curettes and Molten or Jacquette 34/35 curettes are used to completely remove the granulation tissue under medium magnification (×10 to × 16). Large curettes, such as a 33 L spoon excavator or a #86 Lucas bone curette are suitable for the enucleation of large lesions. 
Because of the gradual curve, the Columbia #13 and #14 curettes allow access to the lingual aspect of the root, which is the hardest area to reach. The Jacquette 34/35 scaler allows efficient removal of tissue from the junction of the bone crypt and the root. 
Apical root resection
Von Arx et al. recommended a resection of the apical 3 mm, followed by the preparation of a root-end cavity 3 mm deep, making the "therapeutic length" 6 mm.
Determining how much root tip to resect depends on the incidence of the lateral canal and apical ramifications at the root end. This question was examined by using the Hess model of root anatomy. Using a computer system, the authors resected the roots of the Hess models 1, 2, 3 and 4 mm from the apex, counting the incidence of lateral canals and apical ramifications at each level. Results of this study revealed that resecting 1 mm off the apex reduces 52% of apical ramifications and 40% of lateral canals; 2 mm off the apex reduces 78% of apical ramifications and 86% of lateral canals. Three millimeters off the apex reduces 93% of apical ramifications and 98% of lateral canals. 
Coupled with a root end preparation depth of 3 mm, 6 mm of infectious etiology in the canal space will have been effectively treated. There are, however, 2 notable exceptions to this rule. First, if the level of resection is such that it leaves a root geometry that is significantly curved at that level, then the root end preparation will be compromised. The preparation tips, by design, are 3 mm long, and are not designed to follow curves like a root canal file. Hence, the preparation will be shallower than required because of the tip's impact on the curve or, if forced longer, can, in fact, perforate the external root surface. This situation can be remedied by increasing the length of the resection past the curve, provided the overall length of the remaining portion of the root does not compromise the crown-root ratio.
The other exception occurs when the root in question has undergone a resorptive process and is shorter than normal. In this instance, part of that ideal 3-mm length has been eliminated involuntarily. Comparison of the root length of the contralateral tooth can assist in determining how much more of the apex needs to be removed if any. At the very least, the resorbed root apex would likely need to be flattened somewhat to allow for efficient root end preparation and filling/finishing. 
Elimination or minimization of the bevel angle is one of the most important benefits of microsurgery. With the traditional rotary bur, the steep bevel angle of 45-60° was recommended. The purpose of this steep bevel was simply for access and visibility. In fact, beveling causes significant damage to the tissue structures, that is, buccal bone and root [Table 2]. 
|Table 2: Comparison of bevel angles created by microsurgical and traditional techniques|
Click here to view
(1) The amount of leakage increased as the slope of the bevel increased; (2) increasing the depth of the retrograde filling decreased the micro leakage; and (3) optimum/minimum depths for the retrograde were as follows: 0° =1 mm, 30° =2.1 mm, 45° =2.5 mm.
Apical curettage with root resection
Since the major cause of periapical lesions is a leaky apical seal with attendant ingress of microorganisms and their toxins, the removal of the diseased periapical tissues by periradicular curettage eliminates only the effect of the leakage, not the cause. Apical surgery, therefore, eliminates not just the removal of the diseased tissue or the root tip, but most importantly, the retrofilling and resealing of the root canal system. 
| The Resected Root Surfaces and Isthmus|| |
With the bright illumination and the range of magnification of the operating microscope from × 4 to × 25, the resected root surface can be examined in great detail. A complete and critical inspection of the resected root surface requires staining of the surface with a contrasting medium, such as methylene blue that stains the PDL and pulp tissues selectively. 
Methylene blue is applied to the dry resected root surface with a microapplicator tip. After a few seconds, the root and the bone crypt are rinsed with isotonic saline to remove the excess stained then dried with a Stropko irrigator/drier. The stained area can then be examined under the microscope (×10 to × 12). If the entire root tip has been resected, the PDL appears as an unbroken line around the root surface. A partial line indicates that only part of the root has been resected. If no definable line can be seen, it probably means that only the bone, and not the root, has been stained. The staining also helps to distinguish craze lines from microfractures; microfractures stain but craze lines do not. 
After resection, the crypt is rinsed with sterile saline until it runs clear but, rather than suction the site dry, the saline is allowed to remain in the crypt. The level of the fluid can be adjusted through judicious suctioning with a microcannula until the whole root end surface can be observed. Not only will this facilitate the accurate positioning of the ultrasonic root-end preparation (USREP) tip without a micromirror, but the fluid itself offers a weak hemostatic tamponade effect. 
The stropko device permits the controlled introduction of air, water, or saline into the apical preparation, so that it can be rinsed and dried easily and effectively. To decrease the risk of air embolism, the existing pressure in the air and water lines leading to the syringe should be reduced to < 10 psi. 
An isthmus is defined as a narrow strip of land connecting two larger land masses or a narrow anatomic part or passage connecting two larger structures or cavities. The isthmus has been called a corridor, a lateral connection, and an anastomosis. It must be cleaned, shaped and filled as thoroughly as other canal spaces.
There are many isthmus types. According to Hsu and Kim, there are five different types. Type I was defined as either two or three canals with no noticeable communication. Type II was defined as two canals that had a definite connection between the two main canals. Type III differs from the latter only in that there are three canals instead of two. Incomplete C-shapes with three canals were also included in this category. When canals extend into the isthmus area, this was named Type IV. Type V was recognized as a true connection or corridor throughout the section.
At the 3-mm level from the original apex, 90% of the mesiobuccal roots of maxillary first molars have an isthmus, 30% of the maxillary and mandibular premolars, and over 80% of the mesial roots of the mandibular first molars have one. ,
| Retropreparation|| |
The objective of the root end preparation is to clean and shape the apical canal so that the filling material placed into the root end, providing a hermetic apical seal.  The ideal root-end preparation can be defined as a Class I cavity at least 3 mm into root dentine, with walls parallel to and coincident with an anatomic outline of the root canal space. 
The conventional root-end cavity preparation technique using rotary burs in a micro-handpiece possess several problems for the surgeon. 
- Access to the root-end is difficult, especially with limited working space
- There is a high risk of a perforation of the lingual root-end or cavity preparation, when it does not follow the original canal path
- There are insufficient depth and retention of the root-end filling material
- The root-end resection procedure exposes dentinal tubules
- Necrotic isthmus tissue cannot be removed.
The USREP procedure is carried out under the microscope at low to middle magnifications (×4 to × 16). ,
In single canal roots, the tip is placed into the center of the canal space. The tip is energized, with enough coolant delivered through the tip to cool and flush the preparation site. The tip is allowed to seek passively its way down the canal, and this will happen readily if Gutta-percha is in the canal. Any high-pitched squeal from the tip indicates either binding in a small, uninstrumented canal, or that the tip is traversing off-angle. The preparation is complete when the full depth of the tip is reached, usually 3 mm. In a root with multiple canals and an isthmus joining them (i.e. the MB root of the maxillary first molar), the two canals (MB1 and MB2) are prepared separately to establish the correct angulation of the preparation, then the isthmus connecting them is prepared at the same angle, but caution should be exercised not to overheat the tip or the root end by prolonged dry cutting.
Maddalone and Gagliani showed overall healing of 92.5% they used 4 loupes, ultrasonic tips and Super EBA root-end fillings. 
A study by Bernardes et al. evaluated the time, occurrence of fracture, and quality of apical cavity preparation with three different ultrasonic diamond tips: Satelec, trinity, and a new type, CVD (chemical vapor deposition), using scanning electron microscopy analysis. The three tips provided regular apical cavity preparations, with no difference among them. 
| Management of Gutta-Percha in Retroprepared Cavity|| |
As the ultrasonic unit is activated, Gutta-percha is thermo plasticized and comes out of the preparation in long strings. After the retro preparation is complete, the Gutta-percha remaining at the base of the preparation is recondensed with a small, ½ mm microplugger, which should provide a smooth, flat base against which the retro filling material can be placed. 
| Inspection of Root-End Preparation|| |
After the retro preparation is completed, the prepared cavity is inspected with a micro mirror at a high magnification (×16 to × 25). 
| Drying the Retropreparation|| |
The debris and moisture were sufficient to prevent the formation of an adequate apical seal and frequently caused the surgery to fail. Stropko instrument allows reliable and successful irrigation and drying of a prepared canal. 
| Root End Filling|| |
The ideal root-end filling material should be biocompatible, bactericidal, or at least bacteriostatic; should be neutral to neighboring tissues, and should provide excellent sealing. Furthermore, it should promote regeneration of the original tissues.
Amalgam was considered the root-end filling material of choice until the 1990s. Later various materials like Super EBA, IRM, GIC, Retroplast, Geriostore, mineral trioxide aggregate are used as a root-end filling material. ,,,,
| Suturing/Closure|| |
After the site has been cleansed of all debris, repositioning and suturing of the flap should be done.
Postoperative instructions should include diet and hygiene restrictions, medication guidelines and chilling of the overlying facial surface with ice. The application of cold controls the amount of swelling from the rebound vasodilatation phase, and, therefore, reduces the postoperative potential for discomfort from swelling. 
| Conclusion|| |
Endodontic surgery has now evolved into endodontic microsurgery. By using state-of the-art equipment, instruments and materials that match biological concepts with clinical practice, it can be believed that microsurgical approaches produce predictable outcomes in the healing of lesions of endodontic origin.
| References|| |
Kim S, Kratchman S. Modern endodontic surgery concepts and practice: A review. J Endod 2006;32:601-23.
Richard Rubinstein. Magnification and illumination in apical surgery. Endodontic topics 2005;11:56-77.
Glickman GN, Hartwell GR. Surgical procedures in endodontics. In: Ingle JI, Bakland LK, Baumgartner JC, editors. Ingle's Endodontics. 6 th
ed. Netherlands: BC Decker Publishers; 2008. p. 1233-94.
Kim S, Pecora G, Rubinstein R. Color Atlas of Microsurgery in Endodontics. Philadelphia: W. B. Saunders; 2001.
Creasy JE, Mines P, Sweet M. Surgical trends among endodontists: The results of a web-based survey. J Endod 2009;35:30-4.
Niemczyk SP. Essentials of endodontic microsurgery. Dent Clin North Am 2010;54:375-99.
von Arx T, Walker WA 3 rd
. Microsurgical instruments for root-end cavity preparation following apicoectomy: A literature review. Endod Dent Traumatol 2000;16:47-62.
Siqueira JF Jr. Aetiology of root canal treatment failure: Why well-treated teeth can fail. Int Endod J 2001;34:1-10.
Kim S. Principles of endodontic microsurgery. Dent Clin North Am 1997;41:391-632.
Velvart P, Peters CI. Soft tissue management in endodontic surgery. J Endod 2005;31:4-16.
Carr GB. Surgical endodontics. In: Cohen S, Burns R, editors. Pathways of the Pulp. 6 th
ed. St. Louis: Mosby; 1994. p. 531.
Velvart P. Papilla base incision: A new approach to recession-free healing of the interdental papilla after endodontic surgery. Int Endod J 2002;35:453-60.
Von Arx T, Kurt B, Ilgenstein B, Hardt N. Preliminary results and analysis of a new set of sonic instruments for root-end cavity preparation. Int Endod J 1998;31:32-8.
Plotino G, Pameijer CH, Grande NM, Somma F. Ultrasonics in endodontics: A review of the literature. J Endod 2007;33:81-95.
Maddalone M, Gagliani M. Periapical endodontic surgery: A 3-year follow-up study. Int Endod J 2003;36:193-8.
Bernardes RA, de Moraes IG, Garcia RB, Bernardineli N, Baldi JV, Victorino FR, et al.
Evaluation of apical cavity preparation with a new type of ultrasonic diamond tip. J Endod 2007;33:484-7.
Tawil PZ, Trope M, Curran AE, Caplan DJ, Kirakozova A, Duggan DJ, et al.
Periapical microsurgery: An in vivo
evaluation of endodontic root-end filling materials. J Endod 2009;35:357-62.
Baek SH, Lee WC, Setzer FC, Kim S. Periapical bone regeneration after endodontic microsurgery with three different root-end filling materials: Amalgam, Super EBA, and mineral trioxide aggregate. J Endod 2010;36:1323-5.
Adamo HL, Buruiana R, Schertzer L, Boylan RJ. A comparison of MTA, Super-EBA, composite and amalgam as root-end filling materials using a bacterial microleakage model. Int Endod J 1999;32:197-203.
Camp MA, Jeansonne BG, Lallier T. Adhesion of human fibroblasts to root-end-filling materials. J Endod 2003;29:602-7.
[Table 1], [Table 2]