Guided tissue regeneration in Guided tissue regeneration in endodontic surgeryendodontic surgery

Regeneration of periodontal defects involves formation of new cementum, new attached periodontal fibers and new bone in a region previously destroyed by periodontal disease.

In principle, In principle, four methods four methods have been described have been described totoincrease the rate of bone formation and to increase the rate of bone formation and to augmentaugmentthe bone volumethe bone volume: osteoinduction : osteoinduction by the use of appropriatby the use of appropriate e growth factors growth factors osteoconductionosteoconduction,,where a grafting material serves as a scaffoldwhere a grafting material serves as a scaffoldfor new bone growth for new bone growth distraction distraction osteogenesisosteogenesis,,by which a fracture is surgically induced andby which a fracture is surgically induced andthe two fragments are then slowly pulled apartthe two fragments are then slowly pulled apartand finally, and finally, guided tissue regenerationguided tissue regeneration, , whichwhichallows spaces maintained by barrier allows spaces maintained by barrier membranes tomembranes tobe filled with new bonebe filled with new bone

Guided tissue regenerationGuided tissue regeneration

The use of membranes to guide bony tissue formation by separating the underlying bone from Nonosseous cells (epithelial cells and fibroblasts)

and space is preserved between the bone surface

and membrane. Osteoblasts derived from the periosteum and bone are selectively induced on the osseous

defect area, facilitating new bone formation.

Guided tissue regeneration:

involves the placement of a barrier membrane to prevent cells other

that PDL cells from migrating first to root surface

Guided bone regeneration:

involves the placement of a barrier membrane and a bone graft

in the periodontal defect. Aim is to enhance bone formation

While GTR is for the regeneration of periodontal

tissue of

natural teeth GBR is for the regeneration

of supporting bone

Historical review of GBRHistorical review of GBR

Regeneration of alveolar bone beneath

cellulose acetate filler implant

- by Boyne PJ.

1964

Healing of bone defects by GTR

- by Dahlin C et al.

1988

Historical review of GBRHistorical review of GBR

Bone formation utilizing titanium-reinforced barrier membrane

- by Jovanovic. 1995

Augmentation of intramembraneous bone beyond the skeletal envelope using an occlusive titanium barrier

- by Lundgren D. 1995

Requirement of Requirement of GBR barrier membraneGBR barrier membrane

Biocompatibility & safety

Cell occlusiveness

Space-making ability

Tissue integration

Clinical manageability & cost effectiveness

- by Teparat T et al. 1998

Indication of GBRIndication of GBR

Extraction site

- Prevention of crestal bone loss

especially when 1 or more wall missing

Correction of inadequate ridge width or shape

- Atrophic alveolar bone reconstruction for implant

placement

Indication of GBRIndication of GBR

Dehicence defects

Apical fenestration

Residual intraosseous defects

- Fresh or incompletely repaired extraction

site

Nonresorbable membraneNonresorbable membrane

Titanium-reinforced expanded

polytetrafluoroethlene(Gorete)

Resorbable membraneResorbable membrane

Collagen barriers

- Bio-Guide, Bio-Mend, Colla Tape

Synthetic polymers

- Vicryl Mesh, Resolut, Resolut XT

Resorbable membraneResorbable membrane

Biologically active membrane:

Platelet-rich plasma

Other barrier materials

- Capset, Lambone

Bio-Gide: Composite Porcine Collagen Membrane

Bio-Oss:XENOGRAFT

Protein extraction of bovine bone to produce porous bone mineral hydroxyapatite

Decalcified Freeze- Dried Bone (D.F.D.B.)Decalcified Freeze- Dried Bone (D.F.D.B.)

Variable osteogenic capacity

Viral particles killed in processing

Limited success in furcations

Available in particles and putty

BMPBMP

Highest concentrations

of BMP gave best clinical results

endodontic-periodontal lesion is a clinical manifestation of the pathologic inflammatory intercommunication between pulpal and periodontal tissues via open structures such as apical foraminalateral, accessory canals, and dentinal tubules

,

primary endodontic lesions, primary endodontic lesions withsecondary periodontic

involvement

primary periodontic lesionsprimary periodontic lesions with secondary endodontic

involvement, true combined lesions

Simon et al classified Simon et al classified endodontic-periodontal lesions endodontic-periodontal lesions

intointo

The treatment of endodontic-periodontal combined lesions requires both endodontic therapy and periodontal regenerative

procedure. The success rate of the endodontic-periodontal combined lesion without a concomitant regenerative procedure has been reported to range from 27%–37% (Hirsch JM1985). This is significantly lower than the reported success rate of 95% with conventional nonsurgical root canal therapy (imura 2007)

Guided tissue regeneration (GTR) therapy introduced in 1980s has been widely used to regenerate lost periodontium from periodontal disease. Both human and animal studies have

demonstrated various degrees of regeneration of bone and attachment apparatus (Nyman S, Gottlow J, Karring T,

Lindhe J.1982). GTR therapy has also been implemented in the endodontic surgeries as a concomitant treatment during

the management of the endodontic-periodontal lesions (Schwartz 2006).

A treatment strategy for the application of the A treatment strategy for the application of the regenerative regenerative

procedures is outlined in Fig. 1 on the basis of theprocedures is outlined in Fig. 1 on the basis of the 26 successful cases reported (Schwartz SA, Koch MA 26 successful cases reported (Schwartz SA, Koch MA

2006) .2006) .

1. Treatment algorithm for periodontic-endodontic combined lesions

The presurgical assessment includes establishing and verifying the nonvital status of the pulp, the extent and severity of the periodontal destruction,. A localized deep probing depth with minimal tooth mobility might have a favorable clinical outcome after the regenerative procedure

Cortellini et al (2001) and others (Schulz A, Hilgers RD, Niedermeier W. 2004) have advocated splinting of the mobile

tooth before GTR procedure because the baseline mobility

has been associated with the smaller clinical attachment gain observed after GTR.

The intrasurgical assessment includes: morphology of the periodontal defect, defect type, material of choice to fill the defect and augment

healing, wound stabilization

combination autogenous bone graft and e-PTFE membrane

has been shown to result in the most favorable regenerative

outcome

A 50-year-old healthy, nonsmoker female Overall periodontal status was stable. tooth #3 showed a localized deep probing depth of 9 mm and a 5-mm gingival recession on the mesiopalatal aspect

of the tooth with grade II mobility. y. It responded to neither the electrical pulp test (EPT) nor

the cold test

no pain on percussion test Periapical radiographic views showed a deep vertical

bony defect extending to root apex of tooth #3, in addition

to the periapical radiolucencies to the mesiobuccal root

Initial diagnosis was pulp necrosis and asymptomatic apical periodontitis, and the tooth was thought to have primary

endodontic

involvement. However, the pattern of periodontal bone loss, with a wide base coronally and narrow extent apically,suggested that there was also primary periodontal involvement in this case. Therefore, the overall classification of this case was an endodontic-periodontal combined lesion.

• RCT,SRP during control phaseGTR after 1 month

Radiographic evidence of bone fill post surgery is not reliable

because of variation in angulation of X-ray beam and variations in processing film between preoperative and

postoperative radiographs.