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Endodontic surgery

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basics in endodontic surgeries, flaps, hemostasis

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Endodontic surgery

  1. 1. ENDODONTIC SURGERY POSTGRADUATE DEPARTMENT OF CONSERVATIVE DENTISTRY AND ENDODONTICS UNDER GUIDANCE OF :- Prof. Dr Riyaz Farooq (HOD) Dr Aamir Rashid (Asst. Prof.) Dr Fayaz Ahmed (lecturer) Presenter- Ashish Choudhary PG student Part I: Basics
  2. 2.  “Surgery is the first and the highest division of the healing art, pure in itself, perpetual in its applicability, a working product of heaven and sure of fame on earth" - Sushruta (400 B.C.) Introduction
  3. 3. CONTENTS Instruments & operatory setup  Local anesthesia  Soft tissue access  Hard tissue access  Localized hemostasis Historical aspects to endodontic surgery  Classification  Rationale of endodontic surgery  Indications  Contraindications  Anatomic considerations
  4. 4. HISTORICAL ASPECT TO ENDODONTIC SURGERY…  A Mandible in Egypt from the 4th dynasty (2900 to 2750 BC) contained holes, that could have been made for relief of pain.  The first recorded endodontic surgical procedure was the incision and drainage of an acute endodontic abscess performed by Aetius, a Greek physician–dentist, over 1,500 years.
  5. 5. Intentional replantation  11th century – Abulcasis  1561 – Pare  1712 – Fauchard  1756 – Pfaff  1768 – Berdmore  1778 – Hunter 1839 – Harris recommended the use of ‘lancet or sharp, pointed knife’ to puncture the tumour on the gums 1845 – Hullihan operation or rhizodontropy (making a hole through the gum, the outer edge of the alveolar process, and the root of the tooth into the nerve cavity and the opening into the blood vessels of the nerves) 1843 – Desirabode was the first to report root-end resection later Magitot follwed him in 1860’s and 1870’s
  6. 6. 1880 – Brophy reported root-end resection with immediate root canal fill and management of the apical filling in a patient with extraoral fistula Sir G. V. Black  G. V. Black in 1886, Farrar in 1884 and Grayston in 1887 also recommended for amputation of roots in neglected long term abscess
  7. 7. 1890’s – Carl Partsch, a surgeon turned dentist, from Germany developed root-end resection techniques under chloroform and cocaine anaesthesia Carl Partsch 1895 – 1900’s: Partsch I and Partsch II methods Partsch I method – vertical incision directly over the root and pack the surgical area with iodoform to stop hemorrhage (marsupialization) Partsch II method – complete cyst removal followed by a form of immediate soft tissue apposition and suturing.
  8. 8. 1910 - William Hunter promulgated the focal infection theory. 1915 – Neumann provided the first detailed anatomical description of the relationships of the mandibular roots to both osseous and neurovascular structures Sir William Hunter 1926 – Neumann proposed a split thickness flap, which in design is known as the modern day Oschenbein-Luebke flap
  9. 9. 1935 – Karl Peter classified the position of the inferior alveolar canal relative to the molar root, in addition to providing descriptive relationships of the maxillary sinus and its size and position relative to the roots of maxillary teeth.
  10. 10. 1958- Messings gun 1960- Digital Optical Microscopes 1950’s- Development of microsurgery…. 1993- MTA as root end filling material (Torabinezad)
  11. 11. Classifications of Endodontic surgery 1. Root resection or apical curettage following an orthograde filling, either in one stage or in 2 steps. 2. Orthograde filling during root resection or periapical curettage 3. Root resection & retrograde filling 4. Root resection & retrograde filling following an orthograde filling( 1 or 2 stage procedure) GROSSMAN:
  12. 12. INGLE: Surgical drainage 1. Incision and drainage 2. Cortical trephination (Fistulative surgery) Replacement surgery (extraction/replantation) Implant surgery 1. Endodontic implants 2. Root-form osseointegrated implants Periradicular surgery 1. Curettage 2. Biopsy 3. Root-end resection 4. Root-end preparation and filling 5. Corrective surgery 1. Perforation repair a. Mechanical (iatrogenic) b. Resorptive (internal and external) 2. Root resection 3. Hemisection
  13. 13. Cohen and Burns: Class A Class B Class C Class D Class E Class F
  14. 14. Periradicular surgery - Curettage - Root-end resection - Root-end preparation Fistulative surgery - Incision and Drainage - Cortical trephination - Decompression Corrective surgery - Perforative repair - Periodontal management - Intentional replantation Gutmann: Weine: Periapical surgery  Curettage, apicoectomy and retrograde filling.  Surgery for root fractures Amputational surgery  Incision for drainage  Apical surgery  Corrective surgery  Root amputation, hemisection, bicuspidization Walton:
  15. 15. Rationale for surgical endodontic treatment !!!!  Nowdays, multiple treatment planning options are available for root treated teeth that develop recurrent periapical pathosis or have periapical lesions that fail to heal following adequate root canal treatment. “Surgery is always the second best. If you can do something else, its better” - John Kirklin
  16. 16. Non surgical retreatment or surgical intervention???  success of endodontic therapy ranges from 53 to 98% when performed the first time, while that for retreatment cases with periapical lesion is lower Scand J Dent Res 1979;87:217–24. J Endod 2004;30:1– 4. Int Endod J 1998;31:155– 60. Endod Topics 2003;6:114 –34. Nair PN. GOOD ENDO !!! POOR ENDO !!! Go for surgrical intervention
  17. 17. Specific indications for periradicular surgery today Ingle; 6th edition  Failure of nonsurgical retreatment (treatment has been rendered at least two times)  Failure of nonsurgical (initial) treatment and retreatment is not possible or practical or would not achieve a better result, or  When a biopsy is necessary “ It is paramount that these indications must be in the best interests of patient, within the skills of clinician, and reflective of biological pinciples of endodontic therapy”
  18. 18. What about Resurgery??? 35.7% healed successfully after resurgery, 26.3% healed with uncertain results and 38% did not heal at the one-year follow-up. J. Peterson & J. L. Gutmann International Endodontic Journal, 34, 169–175, 2001 Reasons for failure:  Unsatisfactory preparation at the apical end  Advancing marginal periodontitis  Coronal leakage through faulty restorations  Anatomic aberrations that were not addressed during surgery  Iatrogenic damage to tooth or periodontium Nonsurgical intervention alone is NEVER an option here
  19. 19. INDICATIONS  Need for surgical drainage  Failed nonsurgical endodontic treatment 1. Irretrievable root canal filling material 2. Irretrievable intraradicular post 3. Calcific metamorphosis of the pulp space 4. Procedural errors  Instrument fragmentation  Non-negotiable ledging  Root perforation  Symptomatic overfilling 5. Anatomic variations  Root dilaceration  Apical root fenestration  Biopsy  Corrective surgery 1. Root resorptive defects 2. Root caries 3. Root resection 4. Hemisection 5. Bicuspidization  Replacement surgery A. Replacement surgery 1. Intentional replantation (extraction/replantation) 2. Post-traumatic B. Implant surgery 1. Endodontic 2. Osseointegrated
  20. 20. Need for surgical drainage  Surgical drainage is indicated when purulent and/or hemorrhagic exudate forms within the soft tissue or the alveolar bone as a result of a symptomatic peri- radicular abscess.  Surgical drainage may be accomplished by (1) Incision and drainage (I &D) of the soft tissue or (2) Trephination of the alveolar cortical plate.  An incision should be made through the focal point of the localized swelling to relieve pressure, eliminate exudate and toxins, and stimulate healing.  Cortical trephination is a procedure involving the perforation of the cortical plate to accomplish the release of pressure from the accumulation of exudate within the alveolar bone.  Apical trephination involves penetration of the apical foramen with a small endodontic file and enlarging the apical opening to a size No. 20 or No. 25 file to allow drainage from the periradicular lesion into the canal space.
  21. 21. Fig. Incision & drainage through drain
  22. 22. Cortical trephination Apical trephination
  23. 23. Failed nonsurgical endodontic treatment  Result from incomplete removal of intracanal irritants & lack of complete obturation.  Persistently enlarging or newly developing radiolucencies associated with previously filled canals are a sign of failure.
  24. 24. Anatomic variations Calcific metamorphosis Canal aberrations Lateral canals Apical delta Internal & External resorption
  25. 25. Procedural errors Instrument separartion Nonnegotiatable ledges Symptomatic overfilling
  26. 26. Procedural errors Overinstrument & apical fracture Rooot perforations Root fractures
  27. 27. Biopsy Teeth with vital pulp with mulitilocular radiolucencies Panoramic radiograph shows the extent of this lesion Biospy revealed the presence of keratocytes
  28. 28. Corrective surgery Resorptive defects Replacement surgery Close proximity to mental foramen favours intention reimplantation Tooth replantedTooth extracted
  29. 29. Replacement surgery Initial RCT Sinus tract persists Symptoms persisted after retreatment Atraumatic extraction & apical resection Replantation completed 3 months follow up No symptoms
  30. 30. Contraindications 1. Indiscrimate surgery 2. Poor systemic health 3. Psychological impact on the patient 4. Local anatomic factors
  31. 31. Poor Systemic Health  Complete medical history  Patients with such diseases as leukemia or neutropenia in active state, severely diabetic patients, patients who have recently had heart surgery or cancer surgery & older ill patients are exceptions.  Consideration should be given to patients on anticoagulant medicines (eg., Coumadin); radiation treatment of the jaw; in pregnancy. Psychological impact  Anxious, frightened  masochistic
  32. 32. Local factors factors which make operation difficult  may also delay healing surgical inaccessibility short root lengths missing cortical bone poor bone support proximity to neurovascular bundles, maxillary sinus
  33. 33. Periodontal considerations  Tooth mobility  Periodontal pockets Anatomic considerations Posterior Mandible:  Shallow vestibule  thick alveolar bone  Mental foramen  average location was 16 mm inferior to the cementoenamel junction (CEJ) of the second premolar, although the range was 8 to 21 mm, Oral Surg Oral Med Oral Pathol Oral Radiol Endod 85:457, 1998.
  34. 34.  Mandibular canal  Cone-beam computed tomography (CBCT) imaging can be very useful  Periapical radiographs taken from two vertical angulations, 0 degrees (parallel technique) and −20 degrees, may help determine the buccolingual position of the canal. average vertical distance from the superior border of the mandibular canal to the distal root apex of the mandibular second molar is approximately 3.5 mm. This increases gradually to approximately 6.2 mm for the mesial root of the mandibular first molar and to 4.7 mm for the second premolar
  35. 35. Posterior Maxilla:  Maxillary sinus  Perforation of the sinus during surgery is fairly common (10% to 50%) Int J Oral Maxillofac Surg 28:192, 1999. Int J Oral Surg 3:386, 1974. J Endod 24:260, 1998.  Even without periradicular pathosis, the distance between the root apices of the maxillary posterior teeth and the maxillary sinus sometimes is less than 1 mm Int Endod J 35:127, 2002  Fortunately, perforation of the maxillary sinus rarely results in long-term postoperative problems
  36. 36.  No difference in healing compared with similar surgical procedures without sinus exposure.  membrane usually regenerates, and a thin layer of new bone often forms over the root end, although osseous regeneration is less predictable Dent Clin North Am 41:563, 1997. 549.  If the maxillary sinus is entered during surgery, special care must be taken to prevent infected root fragments and debris from entering the sinus. (Telfa gauze, sutures)  use of orascope or endoscope, in case of displacement of root tip in sinus  role of vertical releasing incision
  37. 37.  Palatal root  reached from either a buccal (transantral) or palatal approach  Take care of anterior palatine artery while taking the palatal approach  ligation of the external carotid artery may be necessary, if artery is severed  An acrylic surgical stent may be fabricated before surgery to assist repositioning of the flap and help prevent pooling of blood under the flap.
  38. 38. Anterior maxilla & mandible:  access to the root apex in some patients may be unexpectedly difficult because of long roots, a shallow vestibule, or lingual inclination of the roots  Surgery of upper centrals: presence of incisive canal & its contents.  Periradicular surgery on mandibular incisors often is more challenging than expected. The combination of lingual root inclination, a shallow vestibule, and a prominent mental protuberance all can increase the degree of difficulty, as can proximity to adjacent roots and the need for perpendicular root-end resection and preparation to include a possible missed lingual canal.
  39. 39. PATIENT PREPARATION FOR SURGERY Informed Consent Issues Specific to Surgery  patient must be thoroughly advised of the benefits, risks, and other treatment options and must be given an opportunity to ask questions.  Although the incidence of serious complications related to surgical procedures is very low, patients should be advised of any risks unique to their situation.  Prompt attention to any surgical complications and thorough follow- up are essential from a medicolegal standpoint.
  40. 40. Premedication: NSAIDs  Administration of an NSAID, either before or up to 30 minutes after surgery, enhances postoperative analgesia  The combination of preoperative administration of an NSAID and use of a long-acting local anesthetic may be particularly helpful for reducing postoperative pain.  Ibuprofen 400 mg provides analgesia approximately equal to that obtained with morphine 10 mg and significantly greater than that from codeine 60 mg, tramadol 100 mg, or acetaminophen 1000 mg Oral Maxillofac Surg 47:464,1989. J Am Dent Assoc 108:598,1984. McQuay H, Moore R: An evidence based resource for pain relief, Oxford, 1998, Oxford University Press.
  41. 41.  The analgesic effectiveness of ibuprofen tends to level off at about the 400 mg level (ceiling effect), although a slight increase in analgesic potential may be expected in doses up to 800 mg. Antibiotics  Controversial issue!!!  The current best available evidence does not support the routine use of prophylactic antibiotics for periradicular surgery. Evid Based Dent 7:72, 2006.  For most patients, the risks of indiscriminate antibiotic therapy are believed to be greater than the potential benefits. J Am Dent Assoc 131:366, 2000.
  42. 42.  Although routine use of prophylactic antibiotics for periradicular surgery is not currently recommended, clinical judgment is important in determining exceptions to the general rule.  For example, immunocompromised, diabetic patients, may be good candidates for prophylactic antibiotic coverage. Antimicrobial mouthwash  Chlorhexidine gluconate (0.12%) often is recommended as a mouth rinse to reduce the number of surface microorganisms in the surgical field, and its use may be continued during the postoperative healing stage. American Dental Association, 2008.
  43. 43. Conscious sedation  either by an orally administered sedative or by nitrous oxide/oxygen inhalation analgesia, may be useful for patients who are anxious about the surgical procedure or dental treatment in general.  Benzodiazepines with a short half-life are particularly useful  A typical protocol is a single dose at bedtime the evening before the procedure and a second dose 1 hour before the start of surgery.  In appropriate doses, benzodiazepines and similar drugs may allow for a more relaxed patient and thus a less stressful surgical experience for both patient and surgeon.
  44. 44. INSTRUMENTS AND OPERATORY SETUP Left to right (left section of tray):  Small round micromirror,  medium oval micromirror,  handle for microscalpel,  scissors,  surgical suction tip. Top to bottom(main section of tray):  Carr #1 retractor,  Carr #2 retractor,  TRH-1 retractor,  periosteal elevator,  Ruddle R elevator,  Ruddle L elevator,  Jacquette curette,  spoon curette,  Scaler,  surgical forceps,  mouth mirror,  periodontal probe. Basic tray setup for initial surgical access.
  45. 45. Instrument tray for root-end filling and suturing Left to right (left section of tray):  Two Castroviejo  needle holders,  Castroviejo scissors,  micro tissue forceps Top to bottom (main section of tray):  Cement spatula,  Feinstein super plugger  microexplorer  endoexplorer,  right &left SuperEBA Placing & Plugging instrument,  anterior,left & right microburnisher and pluggers  small,  medium  large
  46. 46. Comparison of microsurgical scalpel (top) to #15C surgical blade. Microsurgical scalpels are particularly useful for the intrasulcular incision and for delicate dissection of the interproximal papillae. Microcondensers in assorted shapes and sizes for root-end filling.
  47. 47. Comparison of standard #5 mouth mirror to diamond-coated micromirrors Retractors used in periradicular surgery. Top to bottom, EHR-1, ER 2, and ER-1 (equivalent to Carr #2 and #1 retractors)
  48. 48. Placement of root end filling material Teflon sleeve and plugger especially designed for placement of MTA Messing gun–type syringe Kit includes a variety of tips for use in different areas of the mouth and a single-use Teflon plunger Hard plastic block with notches of varying shapes and sizes
  50. 50.  Surgeon, assistant, and patient positioned for initiation of surgery.  The patient should be given tinted goggles or some other form of eye protection before the procedure is begun.
  51. 51. LOCAL ANESTHESIA FOR SURGERY Local anesthetics for periradicular surgeries: Lidocaine  Rapid onset,  Profound anesthesia,  Prolonged duration of action,  Low toxicity & allergic potential,  Excellent diffusion rate Articaine  increased ability to penetrate bone Bupivacaine  long duration of effect  postoperative pain control
  52. 52.  Once anesthesia is established, hemostasis in the soft tissues can be enhanced by infiltration with anesthetic solutions containing vasoconstrictors (epinephrine) in conc. of 1:50,000 Anesth Pain Control Dent 2:223-226, 1993)  The local anesthetic is first slowly deposited in the buccal root apex area of the alveolar mucosa at the surgical site and extended two or three teeth on either side of the site.  Usually palatal or lingual infiltration is also required, although this requires a much smaller amount of local anesthetic  After the injections for anesthesia, the surgeon should wait at least 10 minutes before making the first incision.
  53. 53.  because it is composed of loose connective tissue with large interstitial spaces which allow painless injections and rapid diffusion throughout the mucosal tissues. Why in submucosa why not in gingival tissues?? To regain loss of anesthesia during surgery….  Providing supplemental infiltration anesthesia is difficult after a full thickness flap has been reflected  A supplemental block injection may be useful for mandibular teeth and maxillary posterior teeth.
  54. 54.  In the maxillary anterior area, a palatal approach to the anterior middle superior nerve may be helpful  The key to this approach is slow injection of approximately 1 ml of local anesthetic in the area of the first and second maxillary premolars, midway between the gingival crest and the palatal midline.  An intraosseous injection also may be used to regain lost anesthesia, but even when it is effective, the area of local anesthesia often is smaller than desired for a surgical procedure.  As a last resort, the procedure can be terminated short of completion, and the patient can be rescheduled for surgery under sedation or general anesthesia.
  55. 55. SURGICALACCESS  Surgeon must have a thorough knowledge of the anatomic structures in relation to each other, including tooth anatomy.  must be able to visualize the 3D nature of the structures in the soft and hard tissue  trauma of the surgical procedure itself must be minimized, which includes the preservation of tooth and supporting structures.  Tissue and instruments must be manipulated within a limited space, with the aim of removing diseased tissues and retaining healthy tissues.
  56. 56. Soft-tissue Access  surgeon must take into consideration various anatomic features, such as frenum-muscle attachments, the width of attached gingiva, papillary height and width, bone eminence, and crown margins. Vertical Incision  Incision should be made parallel to the supraperiosteal vessels in the attached gingiva and submucosa  No cuts should be made across frenum and muscle attachments.
  57. 57.  incision should be placed directly over healthy bone.  incision should not be placed superior to a bony eminence.  dental papilla should be included or excluded but not dissected.  incision should extend from the depth of the vestibular sulcus to the midpoint between the dental papilla and the horizontal aspect of the buccal gingival sulcus.
  58. 58. Horizontal Incision This incision extends from the gingival sulcus through the PDL fibers and terminates at the crestal bone of the alveolar bone proper.  passes in a buccolingual direction adjacent to each tooth of the dental papilla and includes the midcol region of each dental papilla.  entire dental papilla is completely mobilized. Intrasulcular incision that includes the dental papilla….
  59. 59. Papillary-based incision….  shallow first incision at the base of the papilla and a second incision directed to the crestal bone Submarginal or Ochsenbein-Luebke flap….  Incision must be placed at least 2 mm from the depth of the gingival sulcus.
  60. 60. To include or exclude dental papilla???  papillary-based incision resulted in rapid recession free healing.  In contrast, complete mobilization of the papilla led to a marked loss of papillary height.  use of the papillary-based incision in aesthetically sensitive regions could help prevent papillary recession and surgicalcleft, or double papilla. Lancet 1:264, 1966. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 91:700, 2001.
  61. 61. Flap Design Full mucoperiosteal flaps (a) Triangular (one vertical releasing incision) (b) Rectangular (two vertical releasing incisions) (c) Trapezoidal (broad-based rectangular) (d) Horizontal (no vertical releasing incision) Limited mucoperiosteal flaps (a) Submarginal curved (semilunar) (b) Submarginal scalloped rectangular (Luebke- Ochsenbein)
  62. 62. Triangular flap… Indications  midroot perforation repair  periapical surgery - posterior area - short roots Advantages  easily modified - small relaxing incision - additional vertical incision - extension of horizontal components  easily repositioned  maintains the integrity of blood supply Disadvantages limited accessibilty tension creates on retraction gingival attachment severed
  63. 63. Rectangular flap… Indications  periapical surgery - multiple teeth - large lesions - long or short roots  lateral root repairs Advantages  maximum access & visibilty  reduces retraction tension  facilitates repositioning Disadvantages reduced blood supply to flap increased incision & reflection time gingival attachment violated - gingival recession - crestal bone loss - may uncover dehiscence suturing is more difficult
  64. 64. Horizontal flap… Indications  cervical resorptive defects  cervical area perforations  periodontal procedures Advantages  no vertical incision  ease of repositioning Disadvantages limited access & visibiltiy difficult to reflect & retract predisposed to streching & tearing gingival attachment violated
  65. 65. Semilunar flap… Indications  esthetic crowns present  trephination Advantages  reduces incision & reflection time  maintains integrity of gingival attachment  eliminates potential crestal bone loss Disadvantages limited access & visibiltiy predisposed to streching & tearing tendency for increase hemorhaging crosses root eminences may not include entie lesion repositioning is difficult healing is associated with scarring
  66. 66. Ochsenbein-luebke flap… Indications  esthetic crowns present  periapical surgery - anterior region - long roots  wide band of attached gingiva Advantages  ease in incision & reflection  enhanced visibilty & access  ease in repositioning  maintains integrity of gingival attachment Disadvantages Horizontal component disrupts blood supply vertical component crosses mucogingival junction difficult to alter if size of lesion misjudged
  67. 67. Clinical case of submarginal flap….. Periodontal probing Submarginal incision Flap reflection Flap repositioned & sutured
  68. 68. Tissue Reflection  process of separating the soft tissues (gingiva, mucosa, and periosteum) from the surface of the alveolar bone. Concept of “undermining elevation”  allows all of the direct reflective forces to be applied to the periosteum and the bone.
  69. 69. Tissue Retraction  process of holding in position the reflected soft tissues. general principles to be followed….  Retractors should rest on solid cortical bone  firm but light pressure should be used  tearing, puncturing, and crushing of the soft tissue should be avoided;  sterile physiologic saline should be used periodically to maintain hydration of the reflected tissue;  retractor should be large enough to protect the retracted soft tissue during surgical treatment Grooving technique
  70. 70. Hard-tissue Access 2 biological considerations….  healthy hard tissue must be preserved  heat generation during the process must be minimized. Temperature increases above normal body temperature in osseous tissues are detrimental. Two critical factors determine the degree of injury: how long it remains elevated?? how high the temperature is increased ??
  71. 71. Temp. rise (°C) blood flow initially increases>40°C 46 °C for 2 min blood flow stagnates deactivates alkaline phosphatase 47-50 °C for 1 min reduces bone formation and is associated with irreversible cellular damage and fatty cell infiltration 56°C Scand J Plast Reconstr Surg 18:261, 1984 J Bone Joint Surg Am 54:297, 1972. Ann Intern Med 67:183, 1967 Lancet 1:264, 1966
  72. 72. Time effect  At temperatures above 109° F (42.5° C), for every 1° C elevation in temperature, the exposure time for the same biologic effect decreases by a factor of approximately 2.  Temperatures above 117° F (47° C) maintained for 1 minute produce effects similar to those at 118° F (48° C) applied for 30 seconds.  Temperatures above 127° F (53° C) applied for less than 1 second can adversely affect osteogenesis Int J Oral Surg 11:115, 1982. J Prosthet Dent 50:101, 1983. Acta Orthop Scand 55:629, 1984. Scand J Plast Reconstr Surg 18:261, 1984.
  73. 73.  Several factors determine the amount of heat generated during bone removal, including the shape the bur, the rotational speed, the use of coolant, and the pressure applied during cutting. Shape & Composition of the bur  round bur gentle brushstroke action Do not use diamond bur Use of coolant  If an appropriate irrigant is not used, temperatures can exceed those known to impair bone healing (delayed up to 3 wks)  Coolant reach the cutting surface.
  74. 74. Pressure applied during cutting  Temperatures can rise above 212° F (100° C) when excess pressure is applied during cutting.  A high-speed handpiece that exhausts air from the base rather than the cutting end is recommended to reduce the risk of air embolism OSTEOTOMY  Sometimes, natural root fenestration is present, or in other cases, the cortical bone may be very thin, and probing with a small sharp curette will allow penetration of cortical bone.
  75. 75.  In presence of dense bone, it is best to approach the entry level by one of the following methods: 1. Length of the root measured from a well angled radiograph,& transferring it to surgical site with help of a sterile ruler. 2. Comparing a radiograph taken of a small piece of sterilized gutta-percha or lead foil that has been placed in a small hole drilled at the approximate root tip location.
  76. 76. Barnes identified four ways in which the root surface can be distinguished from the surrounding osseous tissue: (1) root structure generally has a yellowish color (2) roots do not bleed when probed (3) root texture is smooth and hard as opposed to the granular and porous nature of bone, and (4) root is surrounded by the periodontal ligament. Some authors advocate the use of methylene blue dye to aid in the identification of the periodontal ligament.
  77. 77. Localized Hemostasis  Appropriate hemostasis during surgery minimizes surgical time, surgical blood loss, and postoperative hemorrhage and swelling.  Hemostatic agents, generally aid coagulation by inducing rapid development of an occlusive clot, either by exerting a physical tamponade action or by enhancing the clotting mechanism and vasoconstriction (or both).
  78. 78. Preoperative Considerations  Thorough review of the patient’s body systems and medical history increases  Review of the patient’s medications, both prescribed and over-the- counter (OTC) drugs, is essential.  The patient’s vital signs (i.e., blood pressure, heart rate, and respiratory rate) should be assessed.  Anxiety and stress can be alleviated with planning, sedation, and profound local anesthesia.
  79. 79. Local Hemostatic Agents
  80. 80. Collagen-Based Materials….  achieve hemostasis through stimulation of platelet adhesion, platelet aggregation and release reaction, activation of factor XII (Hageman factor),and mechanical tamponade by the structure that forms at the collagen-blood/wound interface.  Osseous regeneration in the presence of collagen typically proceeds uneventfully, without a foreign body reaction.  Collagen-based materials can be difficult to apply to the bony crypt because they adhere to wet surfaces. J Oral Maxillofac Surg 50:608, 1992.
  81. 81. Surgicel It is primarily a physical hemostatic agent which acts as a barrier to blood and then becomes a sticky mass that serves as an artificial coagulum.  Surgicel is retained in the surgical wound & healing is retarded, with little evidence of resorption of the material at 120 days. Gelfoam  gelatin-based sponge that is water insoluble and biologically resorbable  Stimulates the intrinsic clotting pathway by promoting platelet disintegration and the subsequent release of thromboplastin and thrombin
  82. 82. Bonewax  nonabsorbable product composed of 88% beeswax & 12% isopropyl palmitate  retards bone healing and predisposes the surgical site to infection Ferric sulfate  necrotizing agent with an extremely low pH.  agglutination of blood proteins (forms plugs that occludes the capillary orifices)  used for osteotomies smaller than 5mm  application to wound sites has resulted in tissue necrosis for up to 2 weeks, differences in the degree of epidermal maturation, and tattoo formation
  83. 83.  Hemihydrate Medical -grade calcium sulphate (CS) acts as a hemostatic agent by mechanically blocking open vessels  It is resorbed by body in 2-3 weeks  CS pellet is left in bony cavity, where it acts as a barrier to faster growing soft tissues & may aid in bone regeneration by providing matrix for osteoblasts: Bone inductive agent. Used for osteotomies larger than 5mm
  84. 84. Epinephrine pellets  sympathomimetic-amine vasoconstrictor,  Racemic epinephrine cotton pellets (Racellet #3; Pascal Co, Bellevue, WA) contain an average of 0.55 mg of racemic epinephrine hydrochloride per pellet, half of which is the pharmacologically active L-form.
  85. 85. Mechanism of action
  86. 86. Cautery/Electrosurgery  Cautery stops the flow of blood through coagulation of blood and tissue protein, leaving an eschar that the body attempts to slough.  The effect of cautery in the bony crypt during periradicular surgery has not been studied to date  The detrimental effect of applying heat to bone is proportional to both temperature and the duration of application.