Wound healing after periodontal treatment/PART 2
Healing following surgical procedure :
Gingivectomy
Healing will be by second intention (secondary union) which occurs by the formation of granulation tissue which grows from the base of the wound to fill the defect .
The vascular and fibroblastic proliferation which together make up the granulation tissue much more abundant & healing takes much longer than when it occurs by first intention.
The main problem after gingivectomy is for the epithelial cell to cover the open wound , there is little if any regeneration necessary in the connective tissue because an incision at the bottom of the pocket usually will remove all the granulation tissue leaving a clean connective tissue surface . thus, the epithelial cells are the main actors in the healing after gingivectomy.
Steps of healing :
1-the incision exposes many blood vessels of all sized , when the pack is applied a blood clot is formed & the blood vessels are sealed with fibrin to stop further bleeding . the underlying tissue becomes acutely inflamed with some necrosis .
2-the blood clot below the pack contains large numbers of microorganisms . however , these are in most cases quickly phagocytized by pmn which are migrating into the area in large numbers . therefore, the blood clot is likely to be free of bacteria within hours.
3-the next step in healing is the proliferation of macrophages which engulf rbcs & disintegrating pmns , within 1-2 days epithelial cells starts to migrate from the oral mucosa . the epithelial cells migrate on a network of fibrin . sureface epithelization is completed after 5-14 days.
4-under particulary favourable condition epithelial cells can migrate as far as 2mm in 24 hours . after gingivectomy the speed must be considerably less & it may takes 1-2 weeks before the oral epithelial cells reached the tooth surface .
5-if the regeneration occurred in a plaque free tooth surface , free gingival unit will form . this regeneration occurs in coronal direction & appear clinically as a gain in marginal height ((zero pockets)).
6- complete epithelial repair takes about 4-5 weeks , while the complete repair of connective tissue takes about 7 weeks.
7-the gingival fluid after gingivectomy diminishes as healing progresses , because of decrease in vasodilatation & vascularity. Also during the first 4 weeks after gingivectomy , keratinization is less than it was prior to surgery . also pigmentation is diminished in the healed gingiva in patients with physiologic gingival melanosis.
Healing following a flap – operation :
Healing will be by first intention & has many similarities with healing of an incision in the skin . it is more rapid than secondary itention & characterized by the formation of only minimal amounts of granulation tissue.
Steps of healing :
1-immediately after suturing (0-24 hours) a connection between the flap & the tooth or bone surface is established by the blood clot which consists of fibrin , pmns, erythrocytes , debris from injured cells & capillaries at the edge of the wound , there are also bacteria & an exudates as a result of tissue injury.
2- 1-3 days after surgery:the space between the flap & the tooth or bone is thinner, epithelial cells migrate over the border of the flap to contact the tooth . when the flap is closely adapted to the alveolar process , there is minimals inflammatory response.
3-one week after surgery : epithelium is attached to the root by hemidesmosomes & a basal lamina . the blood clot is replaced by granulation tissue derived from gingival connective tissue, the bone marrow & the periodontal ligament .
4-two weeks after surgery : appearance of collagen fibrs parallel to the tooth surface . they are immature , therefore union is still weak , although clinically maybe normal.
5- one month after surgery : a fully epithelized gingival crevice with a well-defined epithelial attachment is present. There is a beginning of functional arrangement of the supracrestal fibers.
Factors affect healing after periodontal
Treatment:
1-local factors:
a-local factors improve healing:
- good debridement .
- immobilization of the healing area.
- pressure on the wound .
- an increase tissue in o2 consumption at the increase in cellular activity.
b- local factors delay healing:
- excessive tissue manipulation .
- trauma & presence of foreign bodies.
- repetitive treatment procedures that disrupt the orderly cellular activity in the healing process.
- inadequate blood supply lead to impair cellular activity necrosis
delay healing.
||-systemic factors:
-Aging (diminishes capacity because of atherosclerosis vascular changes which reduce circulation).
-Patient with generalized infections.
-Diabetes.
-Patient with debilitating diseases.
-Malnutrition(vit.C deficiency-protien deficiency).
-Systemically administered hormones as cortisone.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .