midterm 2 - lecture 6 Flashcards
Following suture placement a periodontal dressing may be applied. In general dressings have no curative properties; they assist healing by _.
Periodontal dressings are mainly used for the following reasons:
-To protect the wound postsurgically
-To obtain and maintain a close adaptation of the mucosal flaps to the underlying bone (especially if the flap has been _ positioned)
-For patient comfort.
protecting tissues during the healing stage
apically
comfort - patient exposed roots - deceases sensitivity
disadvantage of using a _ is that mouth rinsing with antibacterial agents does not prevent the formation of plaque under the dressing. Results from clinical studies suggest that a periodontal dressing may often be unnecessary after periodontal flap procedures and may be usefully replaced by rinsing with chlorhexidine only.
periodontal dressing
A commonly used periodontal dressing is CoePakTM, which is supplied in two tubes. One tube contains _ of various metals (mainly zinc oxide ) and lorothidol (a fungicide). The second tube contains non-ionizing carboxylic acids and chlorothymol (a bacteriostatic agent). Equal parts from both tubes are mixed together immediately prior to insertion
oxides of various metals
Post operative _ control is the most important variable in determining the long-term result of periodontal surgery. Patients should be advised to rinse with 0.12% chlorhexidine (Peridex, Periogard) twice daily during the post operative period until normal plaque control technique can be resumed. It is important to return to and maintain good mechanical oral hygiene measures as soon as possible since antibacterial mouthrinses are not likely to have any influence on subgingival recolonization of plaque.
plaque
Maintaining good postsurgical _ is another important factor affecting the outcome of some types of periodontal flap procedures. This can be accomplished by adequate suturing technique and protection from mechanical trauma to the marginal tissues during the healing phase
wound stability
Following standard flap surgery procedure sutures are usually kept in place for _ days.
7- 10
If tight adaptation of the flap to the root surface is required for a specific procedure one may consider keeping the sutures in place for a longer period of time
Suture removal techniques
A disinfecting mouthwash such as chlorhexidine can be utilized to clean the wound of all debris. The _ is then elevated off the tissue utilizing cotton pliers. The suture is cut as close to the tissue as possible in order to avoid contamination of the wound with suture-associated bacteria.
suture knot is elevated
When removing continuous sutures, each section should be cut and pulled out individually.
Healing wounds proceed through a number of well-defined steps during the process of repair following injury.
These have been categorized into three phases _ _ _
1) inflammation
2) fibroblastic-granulation
3) matrix formation and remodeling.
During the early phase of repair, a _ is formed. In epidermal wounds, this _ bridges the space between two vascular wound margins and serves as a base that epithelial cells migrate across to cover the wound,
providing protection to the underlying connective tissue as healing progresses.
fibrin clot
Periodontal surgical wounds follow a similar healing pattern, but there are differences in this specific wound healing environment from an epidermal wound. When periodontal wounds are sutured, one of the wound margins _ surface.
Additionally, because of the tooth, the healing site communicates with the oral environment during all phase of wound healing.
_ routinely migrates along the inner surface of the wound resulting in a long junctional epithelium interface with the root surface.
is an avascular root surface
Epithelium migrates
Healing by _ intention
(e. g., a clean surgical incision associated with flap surgery)
a) Immediate response after suturing: A blood clot forms between the flap and the tooth or bone surface. The clot contains fibrin reticulum, neutrophils, erythrocytes, platelets, debris of injured cells, and capillaries at the edge of the wound.
primary
primary intention
Within 24 hrs: Neutrophils infiltrate the _
_ migrates from the wound margin and begins to cover the wound.
neutrophils infiltrat connective tissue.
Epithelium migrates
24 hours
primary retention
1 to 3 days:
The space between the flap and the tooth or bone _.
Epithelial cells migrate over the border of the flap, usually contacting_
bone thins
the tooth. 1-3 days
primary intention
_ days Epithelial migration continues. Neutrophils are replaced by macrophages, which eliminate dead or damaged tissue elements.
The incision space begins to fill with granulation tissue. Revascularization is underway.
3 to 7 days:
primary intention
_ days An epithelial attachment to the root forms by means of hemidesmosomes and a basal lamina.
The blood clot has been replaced by granulation tissue derived from the gingival connective tissue, the bone marrow, and the periodontal ligament.
1 week:
primary intention
_ days Collagen fibers begin to appear parallel to the tooth surface.
The union of the flap to the tooth is weak because of the immaturity of the collagen fibers.
2 weeks:
primary intention
_ days Inflammatory cells are mostly gone.
Fibroblasts proliferate and collagen accumulates.
The revascularization process regresses.
A fully epithelialized gingival crevice with a well-defined epithelial attachment is present.
The supracrestal fibers begin to assume a functional arrangement.
1 month:
primary intention
_ days The wound gains tensile strength.
h) Within 6 to 8 weeks:
primary intention
Full thickness flaps which denude the bone, result in _ after 1 to 3 days;
osteoclastic resorption follows and reaches a peak at _ days , declining thereafter.
This results in a loss of bone of about _ mm. The loss is greater if the bone is thin.
superficial bone necrosis 1-3 days
osteoclastic - 4 to 6 days
during primary intention, full thickness flap results in _
about 1mm of bone loss
Healing by secondary intention (e.g., extensive cell/tissue loss due to gingivectomy).
This differs from healing by primary intention as follows: a) Since there is more necrosis, the _ response is more intense.
b) More _ forms to fill the larger defect.
c) Wound _ is much more pronounced
inflammatory response is more intense.
More granulation tissue
Wound contraction is much more pronounced
Summary of wound healing events
a) The wound is debrided by _.
b) _ cells regenerate.
c) _ and _ tissue cells migrate and proliferate.
d) Extracellular matrix proteins (e.g., collagen) are _.
e) Connective tissue and parenchymal components remodel.
f) The wound gains strength.
debridged by inflammatory cells
b) Parenchymal cells regenerate.
c) Parenchymal & connective tissue cells migrate and proliferate.
d) Extracellular matrix proteins (e.g., collagen) are synthesized.
e) Connective tissue and parenchymal components remodel.
f) The wound gains strength.
Outcomes of wound healing after periodontal surgery
_ Damaged tissues are replaced by tissues that do not duplicate the original function or architecture of the original tissues.
This is the usual outcome of therapy.
Repair
Outcomes of wound healing after periodontal surgery
_Damaged tissues are replaced by tissues duplicate the structure and function of the original tissues. Ideally, this should involve the formation of new cementum, periodontal ligament, and alveolar bone.
Regeneration:
Full regeneration is comparatively rare, but is the most desirable outcome of periodontal therapy. Development of techniques to maximize regeneration is an active area of periodontal research.
Factors that make periodontal _ unpredictable
1. The surgical wound is contaminated by many types of bacteria.2. Regeneration requires the concerted action of many specialized types of cells, including cementoblasts, osteoblasts, fibroblasts, junctional epithelial cells, and endothelial cells. 3. Regeneration requires the formation of several specialized junctional complexes (e.g., attachment of epithelium to tooth, PDL to tooth, gingival connective tissue to tooth). 4. The root surface is avascular and can’t contribute to the formation of new blood vessels. 5. Regeneration requires complex interactions between the extracellular matrix and cells.
regeneration unpredictable
