Bone grafts in periodontal therapy
Periodontitis is a multifactorial disease , anatomical changes must be corrected . If left untreated , - defects provide potential harbor for reestablishment .
" Conventional therapy such as scaling , root planing and gingival curettage , are highly effective but do relatively little to prompt the regeneration of lost periodontal supporting structure " Quotes Acton et.al 1994
Bone Grafting is the most common form of regenerative therapy today . The use of bone grafting can be traced to the work of Hegedeus in 1923 . Buebe and silvers ( 1936 ) use boiled cow bone powder to successfully repair intrabony defects in humans .
Os Parum is ox bone that is soaked in potassium hydroxide to remove collagen , in acetone to remove liquid and in a salt solution to remove proteins .
The Ideal characteristics of a Bone graft
link : http://www.ncbi.nlm.nih.gov/pubmed/21724186
- Non- toxic
- Non antigenic
-Resistant to infection
- no root resorption or ankylosis
-strong and resilient
-readily and sufficiently available
-minimal surgical procedure
-stimulates new attachment
Bone grafts classifications :
Autografts - Intraoral / extraoral . Intraoral : Ramus of the mandible , tuberosity of extraction sites . Extraoral : Iliac crest
Allografts - Freeze dried , fresh and tissue transfered from one individual to another genetically dissimilar individual of the smae species . ( Human- humans )
Xenografts - Tissue transferred from one species to naother species ( eg : oxbone )
Alloplast - A synthetic graft or inert foreign body implanted into the tissue .
Autogenous bone grafts ( gold standards among graft materials )
- Corticol bone chips ( Hand chiseled shavings of corticol bone )
- Osseous coagulum ( formed by mixing the bone particles and blood placed in a sterile dappen dish or amalgam cloth . )
- Bone blend ( corticol or cancelleous bone procured with a trephine , placed in an amalgam capsule and triturated to a consistency of a slushy osseous mass . with a range of particle size from 210x105mm )
- Intraoral Cancellous bone and marrow ( Sources are healing extraction sockets , bony wounds or edentulous ridges )
- Iliac bone and marrow autografts
- Bone " swagging "
Shortcomings of autogenous bone grafts : Inflicting surgical trauma on another part of the patient's body , often sufficient bone material is not available and increased time is not viable .
- Freeze-dried human bone
- Decalcified freeze dried bone grafts ( both osteoconductive and osteoinductive , is the best studied and most widely used allograft material today in periodontics )
- Beta-tricalcium phosphate " biologic fillers "
- Hydroxyapatite : synthetic hydroxyapatite obtained from corals , dense HA grafts , are osteophilic , and act as an inert biocompatible fillers
--- Bioactive glasses
- Perioglass : bond to the bone through development of surface later of carbonated hydroxyapatite when exposed to tissue fluids , bioactive glass are covered by double layer of silica gel and calcium phosphate rich layer .
- Biogran : has a narrower range of particle size between 300 - 355 micron , reported to be advantageous for guiding osteogenesis .
- Bovine bone ( Osteograf , Bio-oss )
- Natural corals ( Coraline calcium carbonate )
Due to risk of disease transmission , the WHO recommended three methods of sterilization :
- Autoclaving at 134 celsius for 18 minutes at 132 celsius for 1 hour
- Sodium Hydroxide solution 1 molar for 1 hour at 20 celsius
- Sodium Hypochlorite at least 2% of chlorine for one hour at 20 celsius
- Tetracycline addition to bone graft substitues : Tetracyclines have wide therapeutic usages not only as antimicrobial agent, but also due to their nonantimicrobial properties