GUIDED TISSUE

REGENERATION

By:

Dr. Chander KumarBDS.MCPS

Assistant Professor &Head Of Department (Periodontology)Altamash Institute Of Dental

Medicine Karachi

It is a procedure through which the exclusion of epithelial and gingival connective tissue cells from the healing area by the use of physical barrier may allow or guide periodontal ligament cells to repopulate the detached root surface.

Melcher in 1976 presented the basic concept that PDL in periodontium is the only tissue that contain progenitor cells for cementum, pdl and alveolar bone.

The progenitor cells for the formation of a new connective tissue attachment reside in the periodontal ligament. so a new connective tissue attachment can be achieved if such cells populate the root surface during healing.

In this procedure both gingival connective tissue and gingival epithelium were prevented from contacting the root surface during healing by the use of a barrier membrane.

REGENERATION

It is defined as a reproduction or re constitution of a lost or injured tissue are completely restored. So regeneration of periodontium includes reformatio of cementum, periodontal ligament and alveolar bone (supporting structure).

NEW ATTACHMENT

It means formation of new cementum with inserting collagen fibers on a root surface deprived if its periodontal ligament tissue, whether or not this has occurred because of periodontal disease or by mechanical means.

REATTACHMENT

It means the reunion of surrounding soft tissue and a root surface with preserved Periodontal ligament tissues.

The Theory of Guided Tissue Regeneration

Following the traditional open-flap debridement procedures, fast-moving epithelial tissue often migrates into the defect space, forming a long junctional epithelium. When this occurs, restoration of Cementum, periodontal ligament and bone,

previously lost to the periodontal infection, is often minimal and unpredictable.

The theory of GTR proposes that placing a barrier between the overlying gingival tissues and the defect space prevents the faster-moving epithelium and gingival

connective tissue from migrating into the wound space, allowing time for Cementum, periodontal ligament and bone to repopulate the area.

INDICATION:

1. Intra bony defects (two or three

wall vertical defects interproximal

defects, distal efects)

2.Class II and class III furcation Defects

3. Recession

CONTRINDICATION:1.Medical condition ( certain cardiac condition, uncontrolled diabetes, on anti coagulant therapies or history of taking medicines)

2.Acute infection or contaminated wounds of oralcavity.

3.Allergic to products of bovine

origin

Defect Selection

The following criteria should be observed when choosing defects for GTR therapy: At least 4 - 5mm of attachment loss at the defect site. Sufficient flap dimensions, including an adequate zone of gingival tissue, to allow for

closure over the membrane. The presence of attached keratinized gingiva is helpful.  Some remaining periodontium to facilitate regenerative capacity. A defect morphology that allows for space creation and maintenance.

The specific types of defects that treated include: Class II fraction defects, two or three wall vertical defects, interproximal type defects, distal defects. The success of treating other types of natural tooth defects such can be as Class III fractions is less predictable.

Material used for GTR

Bioabsorable and non bioabsorable barrier materials are available in a variety n of configuration designed for specific application.

First Generation:

• Millipore filter

• Expanded PTFE(Goretax)

• Nucleopore membrane

Second Generation (resorbable):

• Collagen membrane

• Polylactic acid membrane (guidor)

• Vicryl mesh

• Cargile membrane

• Oxidase cellulose

• Hydrolyzable polyster

Third Generation:

In this resorbable materials with growth factors being developed

Surgical Procedure

GTR is not a procedure for the treatment of periodontitis but rather a technique for regenerating defect.Mucoperiosteal flaps are developed in the treatment sites using secular’s incisions. Care coverage must be taken to preserve the attached keratinized gingiva and

interdental papillae, as this will facilitate subsequent membrane coverage Vertical incisions may be utilized to gain greater access to the defect area and assist in membrane coverage. The vertical incisions should be placed at least one tooth mesially and/or distally to the tooth being treated.

At this time, an appropriately sized sheet is chosen and hydrated for approximately 5 to 10 minutes prior to final placement. The membrane may be hydrated in its packaging by introducing sterile water or saline. Hydration will increase the pliability and adaptability of the membrane.

Meticulous debridement of the defect site is now performed. Because residual contaminants could affect the regenerative result, debridement must be extremely thorough. instrumentation is chosen according to preference: hand,

rotary, sonic and ultrasonic devices are effective for root scaling and planning.

Enamel projections associated with fraction defects should be removed with high speed finishing burs. A clean root surface, free of granulation tissue or calculus, should be the end result. Salivary contamination of the wound site should be minimized.

Once the defect has been prepared, the membrane must be trimmed to properly fit the defect site. Note that the membrane will be required to extend beyond the defect margins by a minimum of 3mm mesialy, distally and apically.

The coronal portion of the membrane must lie above the alveolar crest, apical to the gingival margin.The template material is trimmed until the proper configuration is achieved. It is then placed against the collagen membrane.

Placement and Suturing

Technique

An absorbable suture of choice and noncutting needle can be utilized to secure the membrane. The suture must be absorbable to eliminate the need for a second surgical procedure for suture removal.

The membrane should be snug against the tooth root and draped over the surrounding alveolar bone to maintain regenerative space. Placement and suturing technique will be demonstrated for several types of natural tooth defects commonly encountered in clinical practice.

COMPLICATION

Swelling of intra oral tissue,

Thermal sensitivity,

Gingival recession.

Excessive gingival bleeding,

Dehiscence of flap,

Resorption or ankylosis of treated root,

Post operative pain, and Some times little loss of height of crestal bone.

Post-Operative Protocol.

The following items should be considered in treating the GTR patient post-operatively: A broad-spectrum antibiotic tetracycline for 10 days following surgery

•Periodontal packing may be applied

•Patients should rinse with chlorhexidine gluconate twice daily for four weeks following surgery.

The patient should refrain from brushing the treated area for two weeks following surgery. After this period, the patient may be instructed to gently brush the area with a soft toothbrush. Instruction will be dependent on an evaluation of wound healing.

Care should be taken not to irritate the gingival tissues or cause micro-movements to the membrane. For the same reasons, dental floss should not be used at the site prior to four weeks following surgery.

The patient should be seen seven to ten days following surgery for wound evaluation and removal of any closing sutures or periodontal packing. These follow-up visits should be repeated every two weeks there after, up to six to eight weeks following surgery.

At this point, the patient may return to a normal oral hygiene regimen.

Coronal scaling and prophylaxis can be performed at follow-up visits, if indicated.The GTR membrane should be completely absorbed eight weeks following surgery. However, probing and subgingival scaling should not be performed prior to six months,

following surgery to prevent damage to immature regenerated tissues.

Although radiographs maybe taken at six months following surgery, any regenerated bone will be very immature and lack radio density. It is suggested that radio graphs be repeated at a later time in order to truly assess the bone fill. Other assessments of clinical health may be repeated including plaque, bleeding and tooth mobility indices