root conditioning agents
TRANSCRIPT
Periodontium-Gingiva,Alveolar bone,Periodontal ligament,Cementum.
Periodontal diseases-main etiological agent-’’BACTERIA’’.
On the root surface bacteria are mostly gram –ve bacteria.
These bacteria in the cementum of teeth with untreated periodontal disease
Endotoxins(have potent inflammatory agents)
Prevent the growth of FIBROBLASTS and are CYTOTOXIC.
These changes create obstacle to new ATTACHMENT.
So the root must be cleaned of cementum bound endotoxins.
In vitro mechanical removal of cementum is possible and showed new growth of cells(Aleo,et al 1975;Cogen et al 1983,1984)
Root planing removes diseased cementum but it produces a ‘’smear layer’’.
In vivo total removal of cementum is not possible and trace amounts of endotoxins are left behind(JONES and O’HEARY,1978).
TOPICAL CHEMOTHERAPUTIC AGENTS:for detoxification and enhancement of new attachment in:
Cosmetic gingival reconstruction(Miller,1985) Bone augmentation(Yukna,1980) Overcome rapid rate of epithelial proliferation
down along the root.
Use of acids-1st reported in NEWYORK DENTAL RECORD in 1846,later YOUNGER(1893)
Several substances have been used for ROOT CONDITIONING-
These include Citric acid,Fibronectin,Tetracycline.
CITRIC ACID Studies by Urist
showed formation of new bone or cementum on partially or totally demineralised dentin matrix or allogenic bone.
pH-1.0-1.4 Application time-2or
3 min.
MODE OF ACTION Removal of smear layer formed after root planing
This creates a mat like collagen surface with exposed dentinal tubules
PDL cells and gingival FIBROBLASTS adhere better to demineralized root surface.
CITRIC ACID MECHANISM FOR GAINING ROOT COVERAGE EXPOSED ROOT SURFACE
CITRIC ACID Ph 1.0
4microns DEMINERALIZED SURFACE EXPOSED COLLAGEN FIBRILS +EXPOSED COLLAGEN FIBRILS OF FLAP OR GRAFT.
PLASMA FIBRONECTIN FACTOR,FACTOR 13
FIBRIN COVALENT LINKAGE
ACTIONS Accelerated healing and new cementum
formation. No significant action on non-root planed
roots,after root planing-4mm deep demineralized zone is created.
Antibacterial effect.(Daly,1982) Root detoxification(Aleo et al,1975) Prevents migration of epithelium . Enhanced fibroblast growth and stability(Boyko
et al ,1980) Attachment by direct linkage.
TETRACYCLINE HCL Actions-• Antibacterial,exposur
e of root collagen and opening of the dentinal tubules
Demineralization Detoxification Attachment by direct
linkage
DISADVANTAGES Requires high concentrations(>0-5%) Longer application times(>5min) Not so effective as CA in root demineralization
and removal of smear layer. No human histologic or clinical studies show +ve
results as CA.
FIBRONECTIN It is a glycoprotein that fibroblasts require to
attach to root surfaces. Addition of fibronectin-promotes new
attachment. Fibronectin-fibrin sealing system helps in healing
of PERIODONTAL SURGICAL WOUNDS Commercially available in Europe as
‘’TISSUCOL’’.
ACTIONS Enhances the effect of demineralization with
regard to new attachment Enhances cell proliferation from PDL and
SUPRACRESTAL area Conc-0.38/ml saline,has also been used as a
substitute for sutures Chemotactic effect on fibroblasts and
mesenchymal cells.
APPLICATIONS COSMETIC GINGIVAL RECONSTRUCTION PRIOR TO PLACEMENT OF BONE IMPLANTS INFRABONY DEFECTS IMPLANT ADDITIVE(TTC) PRIMARY TREATMENT FOR CL2
FURCATIONS.
CONCLUSION Although not yet fully supported by research on
humans,CA and TTC have significant benefits that cannot be achieved by scaling and root planing alone.
In future they may provide a surface substrate for use of’’ PROTEIN MODIFIERS’’.
Note:’’SYNTHETIC BIOLOGIC PROTEIN MODIFIERS’’-artificially stimulate tissue regeneration.