Periodontal Wound Healing Flashcards
What classical study looked at healing of Epi and CT?
Engler et al. 1966
Ramfjord et al. 1966
What happens in Epi and CT in the first 2 hrs?
Blood clot formation
PMN migrate to both sites
What happens in Epi and CT in the first 9hrs?
Continued PMN migration and formation of poly-band between blood clot and spinous layer
What happens in Epi and CT from 9-13hrs?
Epithelial cell migration and DNA Synthesis
CT continued PMN migration
When does angiogenesis occur in the CT?
12-24hrs (Ramfjord 1966) During this time there is also CT proliferation
What happens from days 1-2 in EPI and CT?
Epithelial DNA synthesis
CT Angiogenesis + proliferation continues
What happens from days 2-5 and 5-7?
Epithelial cell migration
When does the sulcus form?
5-7days healing
What happens from 7-14days?
New keratinized marginal gingiva (Epi)
New FGM formed due to CT proliferation
When is the peak of osteoclastic activity during periodontal surgical healing?
7-14 days
When does CT mature after periodontal surgery?
4-6weeks
Epithelialization of marginal gingiva and sulcus is complete - CT is organized
What are the phases of wound healing?
Hemostasis
Inflammation
Proliferation
Matrix Formation/Remodeling/Maturation
What happens during the Hemostasis phase?
Blood vessel injury > cellular leakage (leukocytes/erythrocytes/plasma cells) > vasoconstriction > platelet aggregation and coagulation
What is the role of a blood clot in healing?
Protects denuded tissues
serves as a provisional matrix for cell migration
What happens during the inflammation phase?
Wound Cleaning takes place
Neutrophils remove debris and bacteria > Monocytes convert to macrophages > Macrophages and Fibroblasts phagocytose remaining debris and bacteria
What happens during the proliferation phase of healing?
Granulation tissue formation
Macrophage release growth factors (induce granulation tissue formation, and fibroblast migration/proliferation) > keratinocytes migrate to form basal cells (epidermal migration begins) > Collagen formation starts > Endothelial cells create a vascular system
What happens during the matrix formation/remodeling/maturation phase?
New collagen rich matrix produced by fibroblasts > wound contraction > wound maturation
How long does wound maturation take?
6 weeks to 1 year
Which phase determines if regeneration or repair will occur?
Matrix formation/remodeling/maturation phase
What characteristics of the oral cavity complicate wound healing in comparison to the rest of the body?
Residual calculus
Rigid - nonvascular tooth surface attached to CT and Epi (vs 2 opposing vascular tissues)
PDL resources
How does healing of periodontium to tooth occur?
Wikesjo et al. 1991
attachment to dentin surfaces is mediated by adsorption of plasma proteins to the surface and subsequent development and maturation of a fibrin clot.
What kind of animal was used for the Engler and Ramfjord 1966 study?
Rhesus Monkeys
What kind of healing occurs after SRP? Citation?
Long Junctional Epithelium
Caton & Zander 1979
Is LJE Better, Equal, or Less protective than JE?
Equal
Magnusson et al. 1983
What kind of healing occurs after MWF? Citation?
LJE
Caton et al. 1980
What are the phases of healing for osseous surger?
Inflammatory Phase
Reparative Phase
Remodeling Phase
What happens during the Inflammatory phase of osseous healing?
How long is it?
2weeks long
Blood clot formation
Cytokines recruit inflammatory cells to the wound area
What happens during the Reparative phase of osseous healing?
Immature new bone matrix and cartilage scaffolding occurs
Scaffold mineralizes over a period of 6-12 weeks forming immature woven bone
What happens during the Remodeling phase of osseous healing?
Lamellar bone replaces woven bone
How much bone loss can you expect after osseous surgery?
Wilderman et al. 1979
6 months: 1.2mm bone resorption
Following 12 months: 0.4mm bone apposition
Net bone loss: 0.8mm
Selipsky 1976
The initial bone loss and later bone apposition after osseous surgery explains why there is initial increased mobility, followed by return to pre-surgical status/
What is the average bone loss following osseous in the interradicular space?
0.23mm
Moghaddas and Stahl 1980
What is the average bone loss following osseous in the Radicular area?
0.55mm
Moghaddas & Stahl 1980
What is the average bone loss following osseous in the Furcation? Citation
0.88mm
Moghaddas & Stahl 1980
What reasons are there for Crown Lengthening procedures?
Biologic Width invasion
Altered passive eruption
Subgingival caries
How long should we wait after CL to place crowns?
(non-esthetic zone)
Lanning et al.
Heals to ~3mm above osseous crest after 3mo with minimal changes in vertical position of the FGM from 3-6mo
How long should we wait after CL to place crowns?
(esthetic zone)
Brägger et al.
6mo after healing there is minimal change in the FGM
Schropp et al. 2003
50% width reduction after the first 3mo following extraction
Evian et al. 1982
Optimal time to harvest graft from socket
8-12weeks
peak in osteogenic activity
What is the sequence of socket healing?
Amler & Salman 1960
- Blood clot fills socket
- Granulation tissue replaces (2-3days)
- Young CT replaces (by 20days)
- Uncalcified Bone Formation
- Filling in socket with primary bone
- Loss of Lamina Dura
- Bone density similar to surrounding alveolar bone
What are the phases of FGG healing?
Oliver et al. 1968
3 phases
Initial (0-3 days)
Revascularization (4-11 days)
Tissue Maturation (11-42 days)
What happens during the Initial phase of FGG healing?
(Oliver et al. 1968)
0-3 days
CT
Exudate accumulates between collagen fibers = Plasmatic Circulation providing cell nutrition
Epi
Degeneration with desquamation of outer layer
Blood supply
None
What happens during the Revascularization phase of FGG healing?
(Oliver et al. 1968)
4-11 days
CT
Dense fibrous union btw graft/periostium
New FGM
Epi
Degeneration + Desquamation of entire graft epi
Epi proliferation from adjacent tissues
Blood supply
Capillary budding along base of graft
What happens during the Tissue Maturation phase of FGG Healing?
(Oliver et al. 1968)
11-42 days
CT
Increased Density
Epi
Increased Thickness
Keratinization occurs at day 28
Blood supply
Reduction in vascularity
When does keratinization of FGG occur?
28 days
Oliver et al. 1968
How much creeping attachment can be expected form FGG?
0.89mm on average from 3-12mo
Matter & Simasoni
How does CTG healing occur?
Guiha
7days - vascularization from periodontal plexus and supra-periosteal plexus
14days - complete graft vascularization
28 days - JE formed
28-60 days - Normal vascularization/oral epi
How much CTG can be exposed?
Up to 30%
Guiha et al. 2001
Bone loss after full vs partial thickness flap
Wood et al. 1972
Partial: 0.98mm
Full: 0.62mm
Fickl et al. 2011
Partial: 0.12mm
Full: 0.64mm
Benefits of microsurgery for healing?
Higher vascular perfusion
less trauma and vessel injury
enhanced root coverage
enhanced wound healing
Burkhardt & Lang 2005
What are the major systemic factors that can effect wound healing?
Smoking and uncontrolled Diabetes
