Category Archives: Complex Odontogenic Infections

Machinery Account

Machinery Account

Return of goods

Should a hire purchase’ customer fail to pay an instalment, the goods as well as the instalments already paid, are liable to be ‘forfeited. If the hire vendor takes possession of the entire goods, the hire purchaser has. no option but to write. off the loss thus incurred. The entries made by the hire purchaser at the time to purchase of the goods will determine what entries have to be passed at the time of the loss of the goods. If the first method is followed (debiting the asset and crediting the vendor with full cash price), the vendor’s account should be transferred to the account of the .asset, and the balance in the asset account should be written off. If the second method is followed, the balance in the asset account should be written off.

Illustration

Kareem Restaurant purchased from E.C. Ltd. a colour TV. steno 1st October: 1998 on the hire-purchase system. The cash price of the set was Rs. 15,000. Terms of payment ere . 1,150 down and Rs. 4,000 half yearly over two years, the first instalment was to. be paid 01;1 31st March’, 1999 . Rate of interest was 12% per annum. Kareem Restaurant wrote off 15%.depreciation per annum on reducing instalments basis and closed its books every year on 31 st March. It could not pay the second instalment 30th September, 1999 and as a consequence, EC Ltd. repossessed the T.V. set, . Prepare T.V. Set Account and the hire vendor’s account in Kareem Restaurant’s ledger, Also Calculate . the loss suffered by Kareem Restaurant on repossession of T.V. set by E.C. Ltd. ‘Make all calculations to the nearest rupee.

In Kareem Restaurant’s Ledger

The is suffered by Kareem Restaurant ‘is Rs. 1,512 in addition to Rs. 641 interest payable for the half.year ended Filth September, 199~tot~ loss thus being Rs. 2,153 Second Method.

BIBLIOGRAPHY

BIBLIOGRAPHY

Andreassen}, Rud ]: Correlation between histology and radiog-
‘raphy in the assessment of healing after endodontic surgery in
70 cases, lilt I Oral Surg 1:161, 1972.
El Decb, ME, Tabibi A.,Jensen MRJr: An evaluation of the use
of amalgam, Cavit-and calcium hydroxide in the repair of furcation
perforations, J Ended 8:459, 19S2.
El-Swiah JM, Walker RT: Rea-oris for apicectomies: a retrospective
study, Ended Dent Traumatol 12:185, 1996.
Forbes G: Apical microsurgery for failed endodontics, Atlas
Oral Maxillo{ilC Surg Clill Nort/t Am 8:1, 2000.
Gutmann JL, Harrison JW: Posterior endodontic surgery:
anatomical consideration and clinical techniques, lilt Ended J
18:8, 1985.
\,\ltm.11111 .II, l larrivon 1\\. ‘i/l~~i(,11 “II./”.IIIlIlio, Bo-ron. j’lll-!,
BIJ(~\\(‘l1 ,> ••-ientitie
(;utlll.tnn JI et <II’ l’/()IJ/clll\(/lill/~ ill cndodontic«: prevention,
i,h’!!!ifiL’cIliCl’I, ,Ill,! 1I11111’IS,’IIIt’lIt ed 3, St Louis. 1997, \lmhy
Harrison JW, jurosky KA: Wound healing in the periodontium
following endodontic surgery. I. The incisional wound, I
EII.lod 17:425, 1991.
Harrison jW, jurosky KA: Wound healing in the pet’iodontium
following endodontic surgery. [I. The dissectional wound, T
Elided 17:5-!-!, 1991.
Harrison JW, jurosky KA: \”‘ound healing in the tissues of the
periodontium following endodontic surgery. III. The osseous
excisional wound, I Ellt/od 18:76, 1992.
Lubow RM, Wayman BE, Cooley RL: Endodontic flap design:
analysis and recommendation for current usage, Oral Surg Oral
M~d Oral PLit/tol 58:207, 1984.
~cDonald N, Torabinejad M: Surgical endodontics. In Walton
R, Torabinejad M, editors: Principles Lllld practice of endodon- .
tics, ed 3; Philadelphia, 2002, WB Saunders.
Morgan LA, Marshall jG: A scanning electron microscopic
study of in vivo ultrasonic root-end preparations, J Em/ad 25:567,
1999.
Pantschev A, Carlsson AP, Andersson L: Retrograde root filling
with EllA cement or amalgam: a comparative clinical study;
Oral Surg Oral Med Oral Patllol 78:101, 1994.
Sauveur G et al: The control of haemorrhage at the operative
site during periradicular surgery, lilt Ended J 32:225, 1999,
Skoner jR et al: I1lood mercury levels with amalgam retroseals:
a longitudinal study, J Elldod 22:140, 1996,
Stromberg T, Hasselgren G, Bergstedt H: Endodontic treatment
of traumatic root perforations in man: a clinical and roentgenological
follow-up study, Sl’en Tandlak Tidskr 65:457, 1972.
Torabinejad M, Chivian 1\’: Clinical applications of mineral
trioxide aggregate, J Elldod 25:197, 1999.
yon Arx T, Walker WA III: Microsurgical instruments for root- .
end cavity preparation following apicoectomy: a literature
review, Endod Dent Traumatol 16:47,2000. >
\ Vitherspoon D, Gutmann J: Haemostasis in periradicular surgery,
lilt E;ldod J 29: 135, 1996.
Zuolo ML, Ferreira MOF, Gutmann JL: Prognosis in periradicularsurgery: a clinical prospective study, lilt Endod J 33:91,2000.

WHEN TO CONSIDER REFERRAL

WHEN TO CONSIDER REFERRAL

Although many of the procedures presented in this chapterappear relatively straightforward, endodontic surgery is often complex and difficult to perform. Cliniciansshould carefully Consider the problems before undertaking such surgeries.

Determining the Cause of Root
Canal Treatment Failure Two steps are critical to success, particularly if surgery is being considered: (1) identification of the cause of faililre
and (2) design of the treatment plan. Frequently, surgery is not the best choice but when necessary must be done appropriately. A specialist is better able to identify these causes and approach their resolution. If the cause of the failure cannot be identifieb, these cases must be considered for referral.

Surgical Dlfflcultfes

In summary, most of the procedures discussed in this chapter require greater training and experience than are provided in an undergraduate dental education program. If the clinician has not had additional postgraduate training and experience, referral must be considered.

REFERENCE S.

1. Grung D, Molven 0, Halse A: Perlaplcal surgery Ina Norwegian county’ hospital: follow-up findings of 477 teeth, 1 £IIIloJ 16:411, 1990. . .

2. Allen RK, Newton CW,’ Brown CE: A statistical analysis of surgical and nonsurgical endodontic retreatment cases, 1 ElldO(lI5:261, 1989. .

3. Houck V et al: Effect of trephination on postoperative pain .and swelling in symptomatic necrotic teeth, Oral Surg Or,,1 Med Oml Path Oral Radiol Ended 90:50i, 2000.

4. Moiseiwitsch JR, Trope M: Nonsurgical root canal ther~py treatment with apparent indications for root-end surgery.’ Ora/ SlIrg Oral Med Oral Path Oral Radio! Endod 86:335, 1998.

5. Danin j.et al: Outcomes of periradlcular surgery in cases with apical pathosis and untreated canals, Oral Sutg Oral Med Oral
Path Oral Radiol Endod 87:227, 1999.

6. Ncaverth EJ, Burg HA: Decompression of large periapical cys- .tic lesrons.J Bndod 8:175,1982.

7. Kvist T, Tut C: Postoperative discomfort associated with surgical and nonsurgical endodontic retreatment, Dent Trm.lmatoI16:71,2000.. ‘

8. Kramper BJ et al: A comparative study of the wound healing · of three types of flap design used in periapical surgery, 10:17, 1984.

9. Davis W, Oakley J, Smith E: Comparison ‘of the effectiveness of etidocaine and lidocaine as local anesthetic agents during oral surgery, Anesth Prog 31:159, 1984. .

10. Battrum DE, Gutmann JL: Implications, prevention, and management of subcutaneous emphysema during endodonnc treatment, Endod Dent Traumatol 11:109, 1995.

11. Fister J, Gross BD~A histologic evaluation of bone response to bur cutting with and without water coolant, Oral SlIrg Oral , Med Oral PathoI49:105, 1980.

12. Lin LM; Gaengler P, Langeland K: Periradicular curettage, Int Endod 129:220, .1996. “

21. johnson B: Considerations iii-the selection of a root-end fill- – • Ing material, Oral SlIrg Oral Med Oral Pa~1 Oral Radlol Endod 87:398, 1999.

22. Rud J, Rud V, Munksgaard EC: Periapical healing of, mandibular molars after root-end sealing with dentinebonded composite, lnt Endod 134:285, 2001.

23. Fouad A, Rivera E, Walton R: Penicillin as a supplement in resolving the localized acute apical abscess, Oral Oral Med Oral Path Oral Radiol Endod 81-:590, 1996.

24. Fuss Z, Trope M: Root.perfcrattons: classification and treatment choices based on prognostic factors, Endod Dent Traumato
12:25 1996.

25. Lee Monsef M Torablnelad M Sealing ability of a mineral trioxide aggregate for repair of lateral root perforations, Endod 19:541: 1993:

26. Holland R et al: Minerai trioxide aggregate repair of lateral root perforations, 1 Endod 27:281,2001 •

27. Molven 0, Halse A, Grung II: Incomplete healing (scar tissue) after periapical surgery: radiographic finmngs) to 12 years after treatment 22:264, 1996.

28. Molven 0, Halse A, Grung II: Surgical management of endodontic failures: Indications and treatment results, lilt Dent I 46:33, 1991. fines P et al: Use of the microscope in endodontics: a report based on a questionnaire, I Ended 25:755, 1999.

29. Bahcall J, DiFiore P, P oulakidas T: An endoscopic technique for endodontic surgery, I Endod 25:132, 1999,

30. kankow H, Krasner P: Endodontic applications of guided tissue regeneration in endodontic surgery, J Ended 22:34, 1996.

31. Douthitt, JC, Gutmann J~ Witherspoon D: Histologic assessment of healing after the use of a bioresorbable membrane in the management ofbuccal bone loss concomitant with pcriradlcular surgery, I Endod 27:404, 2001.

32. Rahbaran S et al: Comparison of clinical outcome of periapical surgery in endodontic and oral surgery units of a teaching dental hospital: a retrospective study, Oral Surg Oral Med Oral Pathot Oral Radial Endod 91:700, 2001.

ADJUNT

ADJUNT

Same of the newer devices and materials have enhanced 1,cases, improved surgical procedures. These include the light and magnification devicesand techniqucs of guided tissue regeneration. Light and  agnification Devices microscope. Relatively recently the microscop has been adapted and used for surgery, .as well as for otherdiagnostic and treatment procedures in endodontics (Fig 17-O).11 Advantages of the microscope include magniflcationand in-line illumination. They also can be adaptedfor videotaping and to transmit the image to a televisionmonitor for direct viewing or recording. These enhancethe view of the surgical field, help identify previouslyundetected structures, and facilitate surgical procedures.Although some clinicians advocate and an! excited aboutthe use of these microscopes, as yet there have not beendemonstrated substantial clinical benefits through longtermcontrolled studies. However, some evidence suggeststhat the microscope use improves on surgical techniques -and short-term outcomes.

FIG. 17-29 Healing by scar tissue. A, Failed treatment because of transportation and perforation, leaving area of canal (arrow) un debrided and unobturated. B, Root end resection, curettage, and root end f!lIing. C, After 2 years, an area of raololucency is seen. Sharp border, separation from apex, and distinct radiolucency show this to be a scar.

FIG. 17-29 Healing by scar tissue. A, Failed treatment because of transportation and perforation,
leaving area of canal (arrow) un debrided and unobturated. B, Root end resection, curettage, and root
end f!lIing. C, After 2 years, an area of raololucency is seen. Sharp border, separation from apex, and
distinct radiolucency show this to be a scar.

FIG. 17-30 SUlylCal rn.crosr ope has been adapted for endodontic procedures, including surgery. Magnification and in-line illumina- . tion enhance visualizauon for diagnosis and treatment. Add-on binoculars for dental assistant are useful adjunct.

FIG. 17-30 SUlylCal rn.crosr ope has been adapted for endodontic
procedures, including surgery. Magnification and in-line illumina-
. tion enhance visualizauon for diagnosis and treatment. Add-on
binoculars for dental assistant are useful adjunct.

connected to a monitor that permits visualization of precise else details of the surgical site.12 This system also. gives the clinician the option of videotaping and recording procedures.

Bone Augmentation
Various substances have been placed in the periradicular surgical cavities in the attempt to enhance bony healing .Because of the location of the cavity, and because most of the periphery is encased in hone or periosteum, bone regeneration is predictable. Such augmentation materials
are of no benefit. and should not be placed.

RECALL

RECALL

Recall evaluations to assess long-term healing are important. Some failures after surgery are evidenced only by radiographic findings. A I-year follow-up is generally a good indicator. If, after 1 year, radiographic evidence shows no decrease in lesion size or lesion size increases, it generally indicates a failure and persistent inflammation. P’ A decrease in lesion size (indicating hard tissue formation) may lead to complete healing and requires evaluation at 6 to 12 months, Of course, persistent. symptoms , such as pain or swelling (or both), presence of sinus tract deep probing defects, or other adverse

FIG. 17-28 A; Post is reduced to well within root, and cavity is prepared. 8, In this cross-section through defect, a lingual wall to the preparation is evident

FIG. 17-28 A; Post is reduced to well within root, and cavity is prepared. 8, In this cross-section
through defect, a lingual wall to the preparation is evident

findings would also indicate failure. Healing  scar tissue after surgery occurs primarily in the maxillary (Fig. 17-29). This is unusual and has a unique radiogr, lphic appearance with an irregular ‘distinct outline. etten separated from the root end. Healing by car tissue considered tobe a successful outcome.

HEALING

HEALING

Healing after endodontic’ surgery is rapid because most tissues being manipulated are’ healthy, with.a good blood supply, and tissue.replacement enables repair by primary intentton.F Both soft tissues (i.e., periosteum, gingiva, alveolar mucosa, periodontal ligament) and hard tissues

FIG. 17-25 Postperforation repair. A, lesion developing lateral to off-centered postsuggests perforation that (B) is identified (arrow) on flap reflection. C, Post is reduced to within root and cavity filled with amalgam (

FIG. 17-25 Postperforation repair. A, lesion developing lateral to off-centered postsuggests perforation
that (B) is identified (arrow) on flap reflection. C, Post is reduced to within root and cavity filled
with amalgam (

FIG. 17-26 External resorption repair. A, Mesially angled radiograph shows defect (arrow) to be lingual. B, After flap reflection, crestal bone. reduction, and rubber dam isolation, defect is prepared (arrow). Margins must be in sound tooth structure. C, Cavity is filled with amalgam and flap apically . positioned. 0, Long-term radiographiG and clinical evaluation is necessary; at times, resorption recurs.

FIG. 17-26 External resorption repair. A, Mesially angled radiograph shows defect (arrow) to be lingual.
B, After flap reflection, crestal bone. reduction, and rubber dam isolation, defect is prepared
(arrow). Margins must be in sound tooth structure. C, Cavity is filled with amalgam and flap apically
. positioned. 0, Long-term radiographiG and clinical evaluation is necessary; at times, resorption recurs.FIG. 17-26 External resorption repair. A, Mesially angled radiograph shows defect (arrow) to be lingual.
B, After flap reflection, crestal bone. reduction, and rubber dam isolation, defect is prepared
(arrow). Margins must be in sound tooth structure. C, Cavity is filled with amalgam and flap apically
. positioned. 0, Long-term radiographiG and clinical evaluation is necessary; at times, resorption recurs.

(i.e., dentin, cementum, bone) are involved. Time and mode of healing varies with each, but involve similar processes. The specifics of short-term healing of soft and hard tissues are discussedIn Chapter 4.

CORRECTIVE SURG1RY

CORRECTIVE SURG1RY

“Corrective surgery is managing defects that have occurred by a biologic response (Le., resorption or iatrogenic (i.e., procedural) error, These may be anywhere on the root, from cervical margin to apex. Many are accessible; others are difficult to reach or are in virtually inaccessible areas. Usually, an injury or defect has occurred on the root. In response to the injury, there may be an inflammatorylesion or one may develop in the future. A corrective procedure is necessary. Generally, the procedure involves exposing, preparing, then sealing the defect, Usually included are removal of irritants and rebuilding the root surface (Box 17-4.

CORRECTIVE SURG1RY

CORRECTIVE SURG1RY

CORRECTIVE SURG1RY

CORRECTIVE SURG1RY

CORRECTIVE SURG1RY

CORRECTIVE SURG1RY

box 17-22

box 17-22

Indications

Procedural errors. Procedural errors are openings through the lateral root surface created by the ope-rator, typically during access, canal Instrumentation, or _post space preparation (Fig. 17-25). i’he result is perforation, whlch presents a difficult surgical challenge, more so.
than repairing damage to a root end. Perforations often require restorative management and completion of the root canal treatment, usually in conjunction with the surgical phase. The location of the perforation influences success; some arc virtually inaccessible. If the defect is on the interproximal, in the furcation, or close to adjacent teeth or to the lingual, adequate repair may not be possible or is compromised. Defects that are too far posterior (particularly on the distal or lingual aspects) may be very difficult to reach. The nature and location of the perforation should be determined with angled radiographs before the decision is made; whether to

BOX 17-23

BOX 17-23

repair surgically, to remove the involved root, or to cxtract.

Contraindications
Anatoni consideration. Consideration must be given to structural impediments to a surgical approach. Few exist. and must can be managed or avoided. Included are various nerve and vessel bundles and bony structures, such as the external oblique ridge. Locution . As mentioned previously the defect must be accessible surgically. This means the clinician he able to locate and, ideally, to readily visualize till’ ‘urgical area handpiece or an ultrasonic instrument generally is necessary to prepare the defect. Therefore the defect m st be reachable, without impedance by .structures or hyack of visibility.

Considerations
Surgrical approach. Repair presents a unique set of problems. The defect may wrap from facial to proxlrr-al to lingual, creating not only difficulties in visualizatlon hut also problems with access and hemostasis and material
placement. A general SlIi,lvline h that the detect h larger and more complex appears on a radiograph.

FIG. 17-24 Special small amalgam carriers are used to place material, which is then packed with. small condensers. Other cement type of materials are carried and compacted with 'paddles and burnishers. A. Frontal view. 8, Cross-section.

FIG. 17-24 Special small amalgam carriers are used to place material, which is then packed with.
small condensers. Other cement type of materials are carried and compacted with ‘paddles and burnishers.
A. Frontal view. 8, Cross-section.

FIG. 17-24 Special small amalgam carriers are used to place material, which is then packed with. small condensers. Other cement type of materials are carried and compacted with ‘paddles and burnishers.
A. Frontal view. 8, Cross-section.

Prognosis, Repairs in the cervical third or furcation in particular have the poorest prognosis. Communication often is eventually established with the junctional epithelium, which will result in periodontal breakdown, loss of
attachment, and pocket formation. This would mean that a periodontal procedure (e.g., crown lengthening) would be required in conjunction with the defect repair.

Surgical Procedure

After the basic. approaches with periapical surgery, the next step is to perform corrective surgery. Flap d~igns are similar but are more limlted.A sulcular incision is usually .required, with at least one vertical incision to form a threecornered flap. A full-thickness flap is reflected and bone removed to expose the defect (Fig. 17-27). Bone removal must-be .adequate to allow maximal visualization and access.IfPossible,a rim of cervical bone should be retained to support the flap and possibly to enhance reattachment; this is frequently not possible with cervical defects.

The facial or lingual cavity is then filled by direct placement of the material. Aclass II (l.e., interproximal, or ‘furcation) cavity requires a matrix. For example, an amalgam matrix band is held in position with fingers or a wedge, then material is packed into the cavity preparation. This matrix is less critical if amalgam is not used. The material is carved flush with the cavity margins. Flap replacement, suturing, and digital pressure are as described earl. Suture removal should be within 3 to (days Postoperative instructions are similar to those after periapical surgery.

PERIAPICAL SURGERY

PERIAPICAL SURGERY

Periapical (i.e., periradicular) surgery includes resection of a portion of the root that contains undebrided or unobturated (or both) canal space. It can also involve reverse filling and sealing of the canal when conventional root
canal treatment is not feasible. It is often performed in conjunction with apical curettage for reasons explained later in this chapter.

Indications

The success of apical surgery varies considerably, depending on the reason for and nature of the procedure. With failed root canal treatment, often retreatment is not possible or a better result cannot be achieved by a coronal approach.’ If the cause of the failure cannot be identified, surgical exploration may be necessary (Fig. 17-1). On occasion an unusual entity in the periapical .region requires surgical removal and biopsy for identification (Fig. 17-2). Those indications for periapical surgery are discussed in the following sections (B9X 17-2).

FIG. 17-1 Surgical exploration. A, Periradicular'lesion on mesial root may be caused by perforation, incomplete debridement (lateral and apical), or vertical root fracture. B, Visualization after flap reflection shows vertical root fracture (arrow); root must be removed or tooth extracted. (Courtesy of Dr. L. Batdossori-Cruz, Universitv of Iowa.)

FIG. 17-1 Surgical exploration. A, Periradicular’lesion on mesial root may be caused by perforation,
incomplete debridement (lateral and apical), or vertical root fracture. B, Visualization after flap reflection
shows vertical root fracture (arrow); root must be removed or tooth extracted. (Courtesy of Dr. L.
Batdossori-Cruz, Universitv of Iowa.)

Restorative Concideration. Root canal treatment may be risky because of problems that may occur from attempting access through a restoration, such as through a crown . on a mandibular incisor. An opening could compromise retention of the restoration or perforate the root. Rather than attempt the root canal treatment, root resection and root-end filling may he preferred to seal in irritants.

Horizontal   Root Fracturel. Occasionaijy,.after a traumatte root fracture, the rical segment undergoes pulp necrosis. Because this cannot be predictably treated from a coro al approach, the apical segment is removed surgtcally after root canal ‘treatment of the coronal portion (Fig. 17-5).

BOX 17-3

Contraindications (or Cautions) for Periapical Surgery
Unidentified cause of root canal treatment failure When conventional root canal treatment is possible Combined coronal treatmentiapical surgery When retreatment of a treatment failure is possible II Anatomic structures (e.q., adjacent nerves and vesj .sels) are in jeopardy I Structures interfere with access and visibility a Compromise of crown/root ratio
D Systemic complications (e.q., bleeding disorders)

Procedural error.’ Separated instruments, ledging, gross overfills, and perforations (Figs: 17-8 and 17-9 on pages 388 and 389, respectively) may result in failure. Although overfilling is not in itself an indication for removal.of the material, surgical correction is frequently necessary in these situations.

fiG. 17·2 Surgical removal-of pathosis. A, Pulp is responsive; this indicates that radiolucent lesion is not endodontic (i.e., pulpal) in origin. B, Because roots must be resected while removing the lesion; root canal treatment is performed. C, Distal root is resected and lesion is excised. D, Biopsy shows this to be an ossifying fibroma.

fiG. 17·2 Surgical removal-of pathosis. A, Pulp is responsive; this indicates that radiolucent lesion is
not endodontic (i.e., pulpal) in origin. B, Because roots must be resected while removing the lesion;
root canal treatment is performed. C, Distal root is resected and lesion is excised. D, Biopsy shows this
to be an ossifying fibroma.

Decompression and. not curettage, which may damage adjacent structures (rig. ] 7-]0 on page 390). Often, decompression alone is” sufficient to manage these lesions; su.r.g’ical correction (i.e., removal) is unnccessary.

Contraindications (or Cautions)

Contraindications (or Cautions)

If other options are available, periapical surgery may no referred choice (Box] 7-3).

Relying on surgery to try to correct all root canal treatment failurescould be .la eled indiscriminate. An important considerationis to first, identify the cause of fallure.vthcn S(,COllcCdesign an appropriate corrective treatment plan. Usually.retreatrnent is indicated and will  the best chance 01success. Surgery to correct a treat men! failure’ forwhichthecause can-rot be identified is often. Surgicalmanagenient at all large .

FIG. 17-3 A, Very small canal· (i.e., calcific metamorphosis) with pulp necrosis and apical pathosis. Canal could not be located with occlusal access. B, Apical resection and root end retrograde amalgam ~~~i~~ . FIG. 17-4 A, Irretrievable fractured post and apical pathosis. B, Root end resection and filling with amalgam to seal in irritants, Hkelyfrom coronal leakage. C, Regeneration of bone is evident after several months; prognosis  to eal.

FIG. 17-3 A, Very small canal· (i.e., calcific metamorphosis) with pulp necrosis and apical pathosis. Canal could not be located with occlusal access. B, Apical resection and root end retrograde amalgam ~~~i~~ . FIG. 17-4 A, Irretrievable fractured post and apical pathosis. B, Root end resection and filling with amalgam to seal in irritants, Hkelyfrom coronal leakage. C, Regeneration of bone is evident after several months; prognosis to eal.

FIG. 17-4 A, Irretrievable fractured post and apical pathosis. B, Root end resection and filling with amalgam to seal in irritants, Hkelyfrom coronal leakage. C, Regeneration of bone is evident after several months; prognosis is good.

FIG. 17-4 A, Irretrievable fractured post and apical pathosis. B, Root end resection and filling with
amalgam to seal in irritants, Hkelyfrom coronal leakage. C, Regeneration of bone is evident after several
months; prognosis is good.

FIG. 17-5 A, Horizontal root fracture, with failed attempt to treat both segments. 8, Apical segment is removed surgically and retrograde amalgam placed. C, Healing is complete after 1 year.

FIG. 17-5 A, Horizontal root fracture, with failed attempt to treat both segments. 8, Apical segment
is removed surgically and retrograde amalgam placed. C, Healing is complete after 1 year.

When conventional root canal treatment is possible. In most situations orthograde conventional root canal treatment is preferred (Fig. 17-11′ on page 391).4 Surgery is not indicated just because debridement and obturation are in the same visit, although there has been a long-held, incorrect notion that single-visit should be accompanied by surgery, particularly if a periradicular lesion is present.

Anatomic considerations. Most oral structures do not interfere with a surgical approach but must be considered, An example is the maxillary sinus, whic may become exposed. Creating a sinus opening is neither unusual nor dangerous. However, caution is necessary to not introduce foreign objects into the opening and to remind the patient not to exert pressure by blowing the nose until the surgical wound has healed (in 1 to 2.weeks).

Poor crOW1Iand root ratio. Teeth with very short roots have compromised bony support and are’ poor candidates for surgery; root end resection in such cases may compromise stability. However, shorter roots may support a relatively long crown if the surrounding cervical periodontium is healthy (see Fig. ’17-5)

Surgical Procedure

The following eleven steps, with modifications as appropriate, make up the typical approach: (1) flap design, (2) incision and reflection, (3) access to the apex, (~) curettage, (5) root end resection, (6) root end preparation and filling, 17) radiographic verification, (8) flap replacement and suturing, (9) postoperative instructions, (10) suture removal, and (11) long-term evaluation. This sequence IS shown in Hg. 17-13 on page 393.

Flcu) design. A properly designed and carefully reflected flap will result in good access and uncqrnplicated healing. The basic principles of flap design should be followed these are detailed in Chapter 8. Although several

FIG. 17-6 A, Irretrievable separated instruments in mesial canals, B, After complete obturation, root is resected to level or obturation and to include files, C, Bone regeneration is occurring apically, but additional monitoring is necessary.

FIG. 17-6 A, Irretrievable separated instruments in mesial canals, B, After complete obturation, root
is resected to level or obturation and to include files, C, Bone regeneration is occurring apically, but
additional monitoring is necessary.

possibilities exist, the three most common incisions are (l) submarginal curved (i.e., semilunar), (2) submarginal, and (3) full mucoperiosteal (i.e. sulcular). The submarginal and full mucoperiosteal incision will have either a three-corner (i.e., triangular) or four-corner. (i.e., rectangular) design.

Submarginal incision. The horizontal component is in attached ~ingiva with one or two ‘accompanying vertical incisions (Fig. 17.-15 on Rage 394). Generally the incision is scalloped in the horizontal line, with obtuse angles at the corners. It is’ used most succe-ssfully in the maxillary anterior region or, occasionally, with maxillary premolars with crowns. ‘Because of the design, prerequisites are at least 4 rom of attached gingiva and good periodontal health.

The major advantage is esthetics. Leaving the gingiva intact around the margins of crowns is less likely to result in bone resorption with tissue recession and crown margin exposure. Compared with the semilunar inci

FIG. 17-7 A, Irretrievable material in mesial and lingual canals anu <If.'lca'pathos.s. B, CH1~ls are retreated but there is Iailu-e C, Treatment is root end resection to level 01 gutta-percha In the Iresl<l' and lingual aspects, D, After 2 years, healing is complete.

FIG. 17-7 A, Irretrievable material in mesial and lingual canals anu <If.’lca’pathos.s. B, CH1~ls are
retreated but there is Iailu-e C, Treatment is root end resection to level 01 gutta-percha In the Iresl<l’
and lingual aspects, D, After 2 years, healing is complete.

ion, the submarginal provides less risk of incising over a bony defect and provides better access and visibillty. dvantages include hemorrhage along the cut mar- !l 0 the surgical site and occasional healing by scarornpared.

11I1I1II1I(ol’erio’>t(‘{// lncision. This is an incision into the gingival sulcus, extending to the gingival crest (rig. ] 7-16 on page 39-+), This procedure includes elevation of interdental papilla, free ningi,’al margin, attached gingl\’a, and alveolar mucosa. One or two vertical iPlaxlI1g incisions may >e used, creating a three- or /lJ’.l-corner design,

FIG. 17-8 A, Overfill of injected obturating material has resulted in pain and paresthesia as a result of damage to inferior alveolar nerve. B, Corrected by retreatment, then .apicectomy, curettage, and a root end amalgam fill

FIG. 17-8 A, Overfill of injected obturating material has resulted in pain and paresthesia as a result
of damage to inferior alveolar nerve. B, Corrected by retreatment, then .apicectomy, curettage, and a
root end amalgam fill

When feasible the full mucoperiosteal design is preferred over the other two techniques. The advantages include maximum access and visibility, not incising over the lesion or bony defect, less tendency for hemorrhage, complete visibility of the root, allowance of root planing and bone contouring, and reduced likelihood of healing with scar formation. The disadvantages ate somewhat more difficult to replace .and to suture; also, gingival recession frequently develops, exposing crown margins or cervical root surfaces (or both) .

To avoid air emphysema, the use of handpieces ,that direct pressurized air.. water, and abrasive particles (or combinations) into the surgical site should not be used.’? Vented high-speed hand pieces or electrical surgical handpieces are preferred during osseous entry, root end resection, or both. Sealed-end air-pressurized handpieces also direct air away from the surgical site. Regardless of the handpiece used, there should be copious irrigation with a syringe or through the handpiece with sterile saline solution. II Enough overlying bone should be removed to expose the area around the apex and at least half the length of the root. Good access and visibility are important; the bony window must be adequate.

FIG. 17-9 Repair of perforation. A, Furcation penoration results in extrusion of material (arrow) and pathosis. 8, After flap reflection and ex'posure, the defect is repaired with mineral trioxide aggregate (MTA). C, Evaluation at 2 years shows successful healing. (Courtesy Dr. l. Baldassari·Cruz, University of Iowa.)

FIG. 17-9 Repair of perforation. A, Furcation penoration results in extrusion of material (arrow) and
pathosis. 8, After flap reflection and ex’posure, the defect is repaired with mineral trioxide aggregate
(MTA). C, Evaluation at 2 years shows successful healing. (Courtesy Dr. l. Baldassari·Cruz, University of
Iowa.)

with a suitably sized sharp curette. although total lesion removal usually does not occur. A cleaner bony cavity wil.l.pave the least hemorrhage and the best visibility. Tissu~ emoval should not jeoPilrdize the blood supply to an adjacent tooth. In addition, some areas of the lesion may be inaccessible to the curettes, such as on the lingual aspect of the root. Portioris of inflamed is um may be left, without compromisin removal is not necessarv.

FIG. 17-10 Decompression of large lesion. 'A, Extensive periradicular lesion failed to resolve. Coronal leakage in either treated tooth is possible. a, Surgical opening is created to defect; polyethylene tube extends into lesion to promote drainage, C, After partial resolution, root end res:ction and filling ~ith amalgam are performed.

FIG. 17-10 Decompression of large lesion. ‘A, Extensive periradicular
lesion failed to resolve. Coronal leakage in either treated tooth is
possible. a, Surgical opening is created to defect; polyethylene tube
extends into lesion to promote drainage, C, After partial resolution,
root end res:ction and fillingith amalgam are performed.

Root end resection. Root end resection is often, but not always, indicated. It is useful in two situations: (1) to gain access to the canal for examination and placement of a root end preparation and restoration and (2) to remove an un debrided or ‘unobturated (or both) portion of a root. This may be necessary in cases with dilacerated roots, ledged or blocked canals, or apical canal space that is inaccessible because of restorations, as well as in accessing of lingual structures.

Ultrasonic instruments offer some advantages of control and ease of use; they also permit less apical root removal in certain situations (Fig. 17-23 on page 397), Another advantage of the ultrasonic tips, particularly when
diamond coated.!” is the formation of cleaner, better shaped preparation. Evidence suggests that success rates are s’lgnificantly improved with ultrasonic preparation.

Amalgam (preferably zinc free), intermediate restorative material (IRM), and Super ethoxy benzoic acid (Super EBA) cement have been commonly used materials. IS Gutta-percha, composite resin, glass ionomer cement, IRM, Cavit,  and different luting cements have also been recommended these materi ls have less.clinical documentation of success. Mineral trioxide aggregate (MTA)has shown favorable biologtc’? and physical properties and ease of handling20 it has become a widely used material.

No single, all-purpose, superior root end-filling material exists. Those that demonstrate the best combination of physical and biologic properties, as well as documentation of clinical success, are amcMgam, MTA, composite resin and reinforced zinc ~xitle cements ‘(e.g., IRM and

FIG. 17-11 This case is poorly done and done for the wrong reasons. A, inadequate root end resection and root end filling does not seal apex. B, Root canal treatment is readily accornplished, with good chance of succ <

FIG. 17-11 This case is poorly done and done for the wrong reasons. A, inadequate root end
resection and root end filling does not seal apex. B, Root canal treatment is readily accornplished,
with good chance of succ <

Super EBA)i one of thesernaren, Is should be selected, according to the conditior should not be used if thefleld is bloody vi if the root end preparation is less than 3 millimeters, or if access is limited. Composite resin with a bonding agent must be placed in a dry field. This material may be used in a shallow, concave preparation .and has shown to besuccessful in molar root end surgertes.F MTA, with its good properties, may be placed. in a field in which some hemorrhage has occurred the final set is not adversely affected by blood contamination. The long-term stability of MTAis unknown, because’ the material is relatively new. It likely has good longevity. Irrigation. The surgical site is flushed with copious amounts of sterile saline to remove soft and hard tissue debris, hemorrhage, blood clots and excess root end-filling  material.

Postoperative instructions. Both oral and written ,’information should be supplied in simple, straightforward descriptions. The wording should ‘minimize anxiety arising from normal postoperative sequelae by describing the ways in which the patient can promote healing and comfort. Instructions inform the patient of what to expect (i.e., swelling, discomfort, possible discoloration, arid some oozing of blood) and the ways in which these sequelae can be prevented, managed, or both. The surgical
site should not be disturbed, and pressure should be maintained (cold packs over the surgical area until bedtime might help). Oral hygiene procedures are indicated everywhere except the surgical site;’ careful brushing and flossing may begin after 24 hours, Proper nutrition and fluids are important but should not traumatize the area.

FiG. 17-12

FiG. 17-12

FIG. 17-13 Periapical surgical procedure. A, Submarginal inciSion, four-corner (i.e., rectangular), reflected flap. Large bony window is created to show apex. B, Root end is resected and prepared (arrow) for fill. C, Amalgam (arrow) has been condensed. 0, Flap is replaced, compressed, and sutured (i.e., interrupted). (Courtesy Dr. T.Eric~son, University of Iowa.)

FIG. 17-13 Periapical surgical procedure. A, Submarginal inciSion, four-corner (i.e., rectangular),
reflected flap. Large bony window is created to show apex. B, Root end is resected and prepared
(arrow) for fill. C, Amalgam (arrow) has been condensed. 0, Flap is replaced, compressed, and sutured
(i.e., interrupted). (Courtesy Dr. T.Eric~son, University of Iowa.)

Suture reinoval and evaluation. Sutures ordinarily are removed in 3 to 6 days, with shorter periods being preferred to enhance healing. After 3 days swelling and discomfort should be decreasing. In addition, there should be evidence of primary wound closure; tissues that were reflected should be in “apposition. Occasionally: a loose or torn suture may result in nonadapted tissue. In these cases the margins are readapted and resutured.

DRAINAGE OF AN ABSCESS

DRAINAGE OF AN ABSCESS

and exudates from a focus of liquefaction necrosis (i.e., abscess). Draining the abscess relieves pain, increases circulation, and removes a potent irritant. The abscess may be confined to bone or may have eroded through bone and periosteum to. invade soft tissue. Managing these or extraoral swellings by incision for drainage is reviewed in Chapters IS and 16.

BOX 17-1 

Categories of Endodontic Surgery
Abscess drainage Periapical surgery Hemisection/root amputation
Intentional replantation Corrective surgery.

BOX 17-2

Indications for Periapical Surgery
Anatomic problems preventing complete  debridement / obturation Restorative considerations that compromise treatment Horizontal root fracture with apical necrosis Irretrievable material preventing canal treatment or retreatment Procedural errors during treatment Large periapical lesions that do not resolve with root Anatomic problems preventing complete debridement/obturation Restorative considerations that compromise treatment Horizontal root fracture with apical necrosis Irretrievable material preventing canal treatment or retreatment

Procedural errors during treatment Large periapical lesions that do not resolve with root canal treatment commurucate with the apex. The- other suggested approach to manage an abscess in bone is called trephination. This is done by attempting to create a pathway with a bur or rotary instrument through gingiva and cortical bone, directly into the abscess. This approach is of questionable effectiveness.

Principles of Endodontic Surgery

Principles of Endodontic Surgery

CHAPTER OUTLINE

DRAINAGEOF AN ABSCESS
PERIAPICALSURGERY
Indications
Anatomic Problems
Restorative Considerations
Horizontal Root Fracture
Irretrievable Material in Canal
Procedural Error
large Unresolved l,esions After Root Canal
Treatment
Contraindlcations (or Cautions)
Unidentifie.d Cause of Treatment Failure
When Conventional Root Canal Treatment is
Possible
Simultaneous Root Canal Treatment and Apical
Surgery .
Anatomic Considerations
Poor Crown and Root Ratio
Medical (Systemic) Complications
Surgical Procedure
Flap Design
Semilunar Incision
Submarginal Incision
Full Mucoperiosteal Incision
Anesthesia
Incision and Reflection
Perlaplcat Exposure
Curettage
Root End Resection
Root End Preparation and Restoration
Root End-Filling Materials

Irrigation
Radiographic Verification
Flap Replacement and Suturing
Postoperative Instructions
Suture Removal and Evaluation
CORRECTIVESURGERY
Indications
Procedural Errors
Resorptive Perforatiow
Contraindications
Anatomic Considerations
Location of Perforation
Accessibility
Co~derations
Surgical Approach
Repair Material
Prognosis Su’r.gICal Procedure
HEALING
RECALL
ADJUNCTS
Light and Magnification Devices
Surgical Microscope
Fiber Optics
Guided Tissue Regeneration
Bone Augmentation
WHEN TO REFERRAL
Training and Experience
Determinlnq the Cause of Root Canal Treatment
Failure
Surgical Difficulties

The management or provenion of pathosis by in this Includes abscess drainage, periaplcal surgery, intentional replantation.

Root canal treatment is generally a successful procedure if the. problem is accurately diagnosed and careful technique Is used. A common misconception is that if conventional root canal treatment fails, surgery is indicated forcorrection. Usually this is not true most failures are be ter managed by retreatment.? At other times surgery is necessary to correct a failure or for other reasons, may be the only alternative to extraction.

The procedures discussed in this chapter are drainage of an abscess, special (l.e. perlradicular) surgery, and corrective surgery)”.