Endo Fall 2017 Sr. Seminar Flashcards
(190 cards)
What is external resorption?
External Resorption: physiologic and pathologic process resulting in the loss of dentin or cementum which initial begins in the periodontium and affects the external surfaces of the tooth
Types of external resorption
External -Surface resorption -Replacement resorption (ankyloses) -Inflammatory resorption -Invasive cervical resorption Internal
Radiographic Features of Internal resorption
Sharp, clearly defined outlines/borders Walls of lesion appear to balloon out Lesion is usually symmetrical Lesion does not shift on angled films Canal or pulp chamber cannot be visualized within the defect
Radiographic Features of External resorption
Margins of the radiolucent lesion will appear ragged and irregular
Lesion is usually asymmetrical
Lesion shifts with angled films
Canal space is visible throughout the root and can be followed unaltered to the apex
Clinical and Histopathologic Features of ICR
Normal / vital response
Often asymptomatic
Resorption typically initiates cervically
“pink spot” mistaken for internal resorption
small opening in cementum
opaque outline of pulp
spreads and surrounds pulp seen in lesion
resistant predentin layer
Natural Barriers to Resorption are…
PDL, cementum, predentin, then reaches pulp
Classifications of External Cervical Resorption
Class 1 = shallow penetration into dentin near cervical area
Class 2 = well-defined lesion close to coronal pulp without extension into radicular dentin
Class 3 = lesion extends into coronal 1/3 of root
Class 4 = lesion extends beyond coronal 1/3 of root
Distribution of Predisposing Factors for resorption
Orthodontics: 24.1% Idiopathic: 16.4% Trauma: 15.1% Surgery near CEJ: 5.1% Non-Vital Bleaching: 2.9% (---> increases to 9.7% when other factors combined) Related to heat and supercool 7% incidence resported in post bleaching ICR avoid by: placement of a sound base (>= 2mm) ramp base cervically no heat sodium perborate and water instead of superoxol
Causes of Root resorption
Periodical disease Excess ortho movement, Trauma, Internal resorption, Ectopic eruption, Tumors or metastatic disease, idiopathic
Tx options and prognosis for resorption
External / Surgical Approach Supra Osseous Defects Pulp maintains vitality Mini flap access Infra Osseous Defects Resorption may extend to canal space Crown lengthening needed Repair may result in periodontal defect Lesion may recur
Restorative materials
Amalgam RMGI Resin Ionomer (best perio healing) -Geristore or Dyract -Clinical and histologic evidence of epithelial and CT adherence
Invasive Cervical Resorption Treatment Success Rates
% Success after 3 years/% Requiring NS Endodontics
Class 1: 100/0
Class 2:100/66.7
Class 3:77.8/95.2
Class4:12.5/100
Summary for Resorption
Summary
-External cervical resorption is not rare
-Occurs in areas often not covered by BWXR’s
-Detected during exam, PSR probing
-Diagnose using angled radiographs, ancillary images
-Treatment planning is critical
-What’s the strategic value of the tooth, how extensive
is the lesion, what are the possible periodontal
outcomes, repair with internal or external approach or
both?
What is surgical endodontics?
- “Surgical endodontics is the treatment of choice when teeth cannot be treated appropriately by nonsurgical means.”
- Endodontic surgery is nota substitute for NS RCT or careless NS RCT
Nonsurgical Retreatment Rationale–
Bergenholtzet al., ScandJ Dent Res, 1979
•Conclusion–Retreatment is the method of choice whenever possible
Indications for retreatment
- Failure to heal after nonsurgical treatment has failed
- Nonsurgical retreatment has been attempted or has also failed
- Anatomic considerations
- Extreme root curvature
- Root resorption
- Iatrogenic Considerations
- Impassable ledges
- Separated instruments
- Gross overfill
- Establish drainage (incision and drainage)
NSRCT not practical due to….
Irretrievable posts or cast crowns
Contraindications to retreatment
•Patient –Psychological condition –Medical condition •MI within last 6 months •Uncontrolled high BP •Bleeding disorders •Brittle diabetes •Dialysis and immunocompromised patients
Local Factors Poor crown: root ratio Periodontal disease Nonrestorable tooth Anatomy Bone thickness Mandibular 2nd and 3rd molars External oblique ridge Zygoma Surgical Inaccessibility
Pre-operative instructions for Surgical Endodontics•
Chlorhexidinegluconate(Peridex)
•Reduces introduced oral flora into site
•Beginning 1 day before surgery
•Continue until suture removal
–Pre-load analgesics before surgery
•Ibuprofen reduces onset and severity of post-op pain (400 –600mg q6hrs)
•Acetaminophen in addition can be synergistic (325mg q6hrs)
Local Anesthesia and Hemostasis for surgical endodontics
•Local anesthesia 1) 2% lidocaine with 1:100k epinephrine •Block anesthesia 2) 2% lidocaine with 1:50k epinephrine •Hemostasis 3) 0.5% marcaine with 1:200k epinephrine •Pain relief
Reactive Hyperemia
Clinical implications
“opening of the flood gates”
usually impossible to re-establish hemostasis
post-surgical hemorrhage and hemotoma
Factors Affecting Flap Design
Amount of attached gingiva present Number of teeth involved Presence and depth of perio pockets Length of roots involved Amount of access needed Presence and size of apical pathosis Esthetic considerations Other anatomical factors (neurovascular bundle and frenum)
Principles of Flap Design
Maintain maximum blood supply to reflected and adjacent tissue
Place incisions over sound bone
Insure flap is of adequate size
Avoid sharp corners (reduced potential for necrosis)
Avoid incisions over bony eminences
Tissue is more friable, tends to pull away and heals by secondary intention
Retract and handle soft tissue with care
Analyze periodontal condition carefully
Incisions Should be Based On
Supraperiosteal blood vessels
They are vertically oriented
Course parallel to long axes of teeth
Vessels which supply alveolar mucosa also supply gingival tissue