BDS 11140 Endodontic Surgery 1 Lecture Notes PDF

BDS 11140 Endodontic Surgery 1 Date : / /20 Aims: The educational aims of this lecture are: To explain indications and contraindications for endodontic surgery To explain the spectrum of endodontic surgery To detail how to perform an endodontic surgery Objectives: On completion of this lecture, the...

BDS 11140 Endodontic Surgery 1 Date : / /20 Aims: The educational aims of this lecture are: To explain indications and contraindications for endodontic surgery To explain the spectrum of endodontic surgery To detail how to perform an endodontic surgery Objectives: On completion of this lecture, the student should have: An understanding of when an endodontic surgery can be of use An understanding of the clinical steps and outcomes of endodontic surgery Definition: Endodontic surgery involves all surgical procedures performed to remove causative agents of periradicular pathosis and to restore the periodontium to a state of biologic and functional health. Endodontic surgery is removal of tissues other than the contents of the root canal to retain a tooth.” Indications: 1. Failure of non surgical retreatment. 2. Failure of non surgical treatment and retreatment is not practical. 3. Need for biopsy. However, the indications can be grouped as follows: 1. Need for surgical drainage: a. Soft tissue (I&D). b. Hard tissue (trephination). 2. Failed non surgical treatment: a. Rendered twice. b. Irretrievable root canal filling/ post. 3. Calcific metamorphosis of pulp space (solid tooth). 4. Procedural errors and non surgical retreatment or correction failed: a. Instruments separation. b. Ledging. c. Root perforation. d. Symptomatic overfilling. 5. Anatomic variations: a. Root dilacerations. b. Apical root fenestration. 6. Need for biopsy. 7. Corrective surgery: a. Root resorption.b. Root caries.c. Root resection (amputation). d. Hemi section. e. Bisection (bicuspidization). 8. Intentional replantation. 9. Implant surgery: a. Endodontic implant. b. Osseointegrated implant. Contraindications: Few contraindications to endodontic surgery exist. 1. Anatomic considerations: The major anatomical landmark of importance to endodontic surgery include: Nasal floor, maxillary sinus, mandibular canal and it’s neurovascular bundle and mental foramen. 2. Patient medical condition. 3. Dentist skill and experience. Classification Of Surgical Procedures: Classification Of Surgical Procedures: A. Incision & drainage (I&D). B. Cortical trephination. 1- Surgical Drainage: A-Incision and drainage (I & D): Surgical drainage is indicated when pus and or exudate form within the soft tissue as a result of periradicular lesion. B-Cortical trephination: It is the surgical perforation of the alveolar cortical plate to release, from between the cortical plates, the accumulated inflammatory and infective tissue exudate that causes pain. Made in the absence of swelling, severe pain and failure of apical trephination to allow for pus drainage. Classification Of Surgical Procedures: a. Curettage b. Root end resection (apicoectomy). c. Root end preparation & filling 2-Periradicular Surgery: A- Preoperative assessment B- Surgical technique: 1. Need for profound local anesthesia and hemostasis. 2. Management of soft tissues. 3. Management of hard tissues. a. Access to root structure. b. Periradicular curettage. c. Root end resection. d. Root end preparation. e. Root end filling. 4. Soft tissue repositioning and suturing. 5. Post surgical care A- Preoperative assessment: The patient must be informed of the prognosis, risks, benefits and the short term effects of the surgery such as pain, swelling, discoloration, and infection. Signed consent forms are essential. The following pre-treatment regimens are recommended: A periodontal examination must be performed prior to surgery to assess for periodontal pockets. Scaling and/or root planing may be required. Patients should be placed on chlorhexidine (0.12– 0.2%) rinses. immediately before surgery and should continue for at least 2 to 3 days afterwards. Patients can begin taking, non-steroidal anti-inflammatory medication one day prior to surgery, or at the latest one hour before treatment. If sedation is to be used, the patient must bring an accompanying person. The following factors should be assessed: 1-General systemic factors, which usually require medical consultation. 2- Local factors: The possible need to remove previous dental restorations that are failing, the need to revise the root filling, to asses tooth restorability. 3-Radiological examination: (CBCT) To assess whether the lesion has perforated the buccal or palatal cortical plates. To assess which root or roots are involved in the lesion. The relationship of the teeth and the associated pathology to important anatomic landmarks ( maxillary sinus, mandibular canal, mental foramen, incisive canal) Early detection of any change in apical bone density B-Surgical technique: 1. Need for profound local anesthesia and hemostasis. 2. Management of soft tissues. 3. Management of hard tissues. a. Access to root structure. b. Periradicular curettage. c. Root end resection. d. Root end preparation. e. Root end filling. 4. Soft tissue repositioning and suturing. 5. Post surgical care 1-Local Anasthesia and Hemostasis: Injection of local anesthestic carpule into the oral tissues prior to surgery has Two important purposes: Anasthesia & Hemostais Without good hemostasis: 1-Impaired Vision of the surgical site. 2-Prolonged surgical procedures.. 3-Increased blood loss. 4-Greater post surgical hemorraghe Hemostasis: Epinephrine is the vasoconstrictor of choice for preiradicular surgery because of its superior potency and effectivness. Available in concentrations 1:200,000, 1:100,000 and 1:50,000 with the latter being the most effective in vasoconstriction. Hemostasis cannot be achieved by injecting into distant sites, additional injections must be administered in the soft tissue in the immediate area of the surgery in addition to nerve block injections for pain control. Rebound phenomenon is due to rebound from α to β response where the restricted blood flow slowly returns to normal. Injecting more anesthesia will never reestablish hemostasis. 2- Soft Tissue Managmnet: A-Flap Design B-Flap Reflection C-Flap Retraction A-Flap Designs: Classification: I. Full mucoperiosteal flaps: a) b) c) d) e) Triangular (single vertical releasing incision) Rectangular (double vertical releasing incisions) Trapezoidal (broad base rectangular) Horizontal (no vertical releasing incision) Papilla-base. II. Limited mucoperiosteal flaps: a) Submarginal curved (semi- lunar) b) Submarginal scalloped rectangular (leubke – oschenbein) Principles and guidelines for flaps: Incision should be placed over solid bone. Extent of the horizontal incision should be adequate to provide visual access with minimal soft tissue trauma. It should extend at least one to two teeth lateral to the tooth to be treated. Avoid incision lines over radicular eminences such as canines and maxillary first bicuspids. Avoid incisions across major muscle attachment. Extent of vertical incisions should be sufficient to allow the tissue retractor to seat on solid bone leaving the apex well exposed. Junction between horizontal and vertical incision lines should either include or exclude the involved interdental papilla. Avoid severely angled vertical incisions. The supraperiosteal vessels assume a vertical course parallel to long axis of teeth. I-Full mucoperiosteal flaps: The entire soft tissue overlying the cortical bone plate is reflected. The advantage of these flaps is keeping intact supraperiosteal vessels. A)Triangular flap: The triangular flap is formed by a horizontal, intrasulcular incision, and one vertical releasing incision Indications: Maxillary incisor region. Maxillary and mandibular posterior teeth. Not recommended for: Teeth with long roots (maxillary canines) Advantages: Good wound healing. Ease of flap re-approximation. Major disadvantage is the limited surgical access. B)Rectangular flap: : Two vertical and a horizontal intrasulcular incision. Advantages: Good surgical access. Disadvantage: Difficult reapproximation of margins. and post surgical stabilization. Indications: Mandibular anteriors. Maxillary canines. Multiple teeth. Contraindication: Mandibular posterior teeth C)Trapezoidal flap: Two vertical releasing incisions which join a horizontal intrasulcular incision at obtuse angles. It creates a broadbased flap. It was assumed that this provide a better blood supply. Disadvantages: More bleeding due to disruption of more of the vertically oriented blood vessels. Shrinkage of soft tissue due to severing of more collagen fibers. Contraindication: Periradicular surgery D)Horizontal (envelope) flap: A horizontal, intrasulcular incision with no vertical releasing incision. It has a very limited application due to the limited surgical access. Not indicated in periradicular surgery Indications: Repair of cervical defects; such as perforations, resorption, cervical caries. Advantages: Improved wound healing. E)Papilla-base Flap: A horizontal incision at the papillary base extending intrasulcular toward the crestal bone. At least one vertical incision is established. Advantage: No recession of the papillae following surgery. Indications: Mandibular and maxillary anterior teeth (esthetic region) II. Limited mucoperiosteal Flaps: They have a submarginal (subsulcular) horizontal, or horizontally oriented, incision, and does not include marginal or interdental tissues. Therefore in this type of flaps more vertically oriented blood vessels and collagen fibres are severed. Submarginal curved ( semilunar) Submarginal scalloped rectangular (leubke – oschenbein) A)Submarginal curved (Semilunar) Flap: A curved incision in the alveolar mucosa and attached gingiva. Advantage Does not disturb the gingival margin and interdental papillae. Disadvantages: Poor surgical access. Poor wound healing due to disruption of blood supply to unflapped tissues. Difficult wound closure. Postsurgical scarring. This flap design is not recommended for periradicular surgery. B)Submarginal scalloped rectangular (luebke – ochsenbein) Flap: A modification of the rectangular flap. It provides the advantages of the rectangular and semilunar flaps. The horizontal incision is placed in the attached gingiva, it is scalloped following the contour of marginal ginigva above the free gingival groove. Advantages: Does not involve marginal or interdental gingivae. Adequate surgical access. Disadvantages: Disruption of vertically oriented blood vessels producing more bleeding. flap shrinkage. Delayed healing and scar formation Indications: In presence of gingivitis or marginal periodontitis. In presence of fixed prosthesis. Considerations in palatal surgery: Palatal approach is difficult due to limited visibility and accessibility. Indicated flap designs: 1. Horizontal (envelope). 2. Triangular. Indications of palatal flaps: Surgical procedures in palatal roots of molars and premolars such as apicectomy, amputation, or perforation repair. Repair of perforations or resorption defects of palatal surfaces of anterior teeth. B- Flap Reflection : : The process of separating the soft tissues from surface of alveolar bone. It should begin in the vertical incision few millimeters apical to its junction with the horizontal incision. Once this part is lifted from cortical plate a periosteal elevator is inserted between it and the bone with its sharp side toward bone. The elevator is then moved coronally so that the marginal and interdental gingivae as well as the wound edge are separated without direct application of dissectional forces. Reflection should not begin also in the horizontal incision in submaginal flaps. B- Flap Retraction : Retractor should rest on sound cortical bone. If retractor rests on the base of reflected tissues then damage of microcirculation and delayed healing occur. Frequent flap irrigation with sterile saline to prevent dehydration. 3- Hard Tissue Management: Osseous entry and root identification Periradicular Curettage Root End Resection Root End Cavity Preparation Root End Filling Osseous entry and root identification -To gain access to the root apex , removal of covering osseous tissue is necessry Two key factors should and must be kept in mind during bony access which are: Healthy hard tissue must be preserved as much as possible Heat generation during the procedure: heat in the osseous tissues up to 47-50˚C for 1 minute greatly reduces bone formation and leads to cellular damage. Technique: Removal of the bone is usually accomplished with a large round bur using a low- or high-speed handpiece. The bone is removed in a brush-stroke fashion with copious irrigation (Maximize cutting efficiency, minimize frictional heat) creating a window over the root apex. A high-speed handpiece that exhausts air from the base rather than the cutting end is recommended to reduce the risk of air embolism To accurately locate the position of the root apex: 1. Measure the entire tooth length with a file on a preoperative radiograph. 2. Probing the bone forcibly may show the presence of small defect. 3. When a small defect is noticed, then a piece of lead sheet or gutta-percha can be placed in it and radiographed 4. In cases with large periradicular lesions, the loss of the cortical plate of bone may directly expose the root apex. Characteristic points to differentiate root surface from bone: 1. Root is yellowish in color. 2. Root texture is smooth and hard, while that of bone is porous and granular. 3. Root does not bleed when probed. 4. Root is surrounded by periodontal ligament. 5. Methylene blue dye is used to identify the periodontal ligament Periradicular Curettage: This procedure can often be performed prior to, or in conjunction with, root-end resection. Indications: 1. 2. 3. 4. 5. To establish access to the root. To remove infected or pathologic tissues from the bone surrounding the root. To remove over extended filling. To remove necrotic cementum. To assist rapid healing and repair of periradicular tissues. Curettage is accomplished with straight or angled surgical bone curettes and periodontal curettes Insert bone curette between soft tissue and bone and apply pressure against the bone to remove the pathologic tissues. Grasp the pathologic tissues with tissue forceps and send them for examination.(biopsy) Avoid penetration of the soft tissue as this may sever the vascular network, and increase local haemorrhage. When soft tissue is adherent, either lingually to the root, periodontal curettes facilitate its removal. Management Of The Root End: The basis for periradicular surgery is twofold: 1-The first objective is to remove the etiologic factors: Eradication of irritant is done through root-end resection to establish access to and remove the diseased tissues. This ensures that the optimum environment for wound healing 2-The second is to prevent recontamination of the periradicular tissues once the etiologic agent has been removed. Root end filling should be placed to seal any remaining irritants within the canal system, thus preventing recontamination of the periradicular tissues. Root End Resection Definition: it is the removal of apical portion of the root. Factors to be considered prior to root-end resection: 1. Instruments used. 2. Extent of root-end resection. 3. Angle of root-end resection. 1- Instruments used: Plain fissure bur produces smoothest surface and least distortion of gutta percha. ER: YAG laser: 1. Clean smooth root surface 2. Sterilize contaminated root apex. 3. Reduction in permeability of cut root surface dentin. 1. The absence of discomfort and vibrations. 2. Reduced risk of trauma to adjacent tissue 3. Reduction of postoperative pain. 4. Hemostasis 2-Extent of root-end resection: The level to which the root-end should be resected will be dictated by the following factors: access and visibility to the surgical site presence and position of additional roots, e.g. an additional palatal or lingual root anatomy of the cut root surface relative to the number of canals and their configuration need to place a root-end filling presence and location of a perforation presence of an intra-alveolar root fracture anatomical considerations, e.g. proximity of adjacent teeth, mental foramen or inferior dental canal, level of remaining crestal bone presence of significant accessory canals, which may dictate a more extensive resection. An apical resection of approximately 3 mm should include most accessory and lateral canals and thus eliminate most residual microorganisms and irritants 3-Angle of root-end resection: Angle of root-end resection used to be beveled 30 to 45 degrees from long axis facially.This was suggested to improve visibility and accessibility However Beveling opens more dentinal tubules and increases risk of leakage. So A bevel of 0-10 is recommended with resection at the level of 3mm. Advantages of zero degree bevel: Exposure of fewer dentinal tubules. Maintains maximum root length. Reduced size of osteotomy. Less apical leakage. Resection should be complete with no segment of the root left unresected. Straight fissure) is positioned at the desired angle and the root is shaved away, beginning from the apex, cutting coronally Advantages: It allows for continual observation of the root-end during cutting. 1 2 Predetermine the amount of root-end to be resected. The apex is resected by cutting through the root from mesial to distal Gain access to soft tissue located lingual to the root. If root-end is in close proximity to vital structures Disadvantage: It may remove more root structure than necessary. Reading material: Students are advised to read details at: 1.Cohen`s pathways of the pulp, 11th edition, 2016, Kenneth M. Hargreaves and Louis H. Berman. (chapters 20-21) 2.Endodontic science (two volumes), 2nd edition, 2009, Carlos Estrela. (chapter24) 3.Problems in endodontics, Etiology, diagnosis and treatment, 2009, Michael Hulsmann and Edgar Schafer. 4.Endodontology, an integrated biological and clinical view, 2013, Domenico Ricucci and Jose F. Siqueira Jr. 5. Clinical endodontics, 3rd edition, 2009, Leif Tronstad. Aims: The educational aims of this lecture are: To explain indications and contraindications for endodontic surgery To explain the spectrum of endodontic surgery To detail how to perform an endodontic surgery Objectives: On completion of this lecture, the student should have: An understanding of when an endodontic surgery can be of use An understanding of the clinical steps and outcomes of endodontic surgery