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Presented by:Dr.Pulak Mishra

PERIODONTAL REGENERATIVE PROCEDURES

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IntroductionBone graft associated proceduresNon Bone graft associated procedures

Removal of the junctional and pocket epithelium

Prevention of their migration into the healing area after therapy

Biomodification of the root surface

Guided tissue regeneration

Biologic mediators (growth factors)

Gene therapy

CONTENTS

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Combined techniqes

Evidence based practice perspective

Conclusion

References

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THE GOALS OF PERIODONTAL THERAPY have long included arresting the disease process, preventing disease recurrence and regenerating periodontium lost as a result of

periodontal disease.

INTRODUCTION

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1. Healing with long junctional epithelium2. Ankylosis of the bone and tooth3. Recurrence of the Pocket4. New attachment with new PDL inserted into

new bone & new cementum5. Any combination of above

POSSIBLE OUTCOME OF THE PERIODONTAL

THERAPY

SOURCES OF REGENERATING CELLS IN THE HEALING

STAGES OF PERIODONTAL POCKET.

AFTER THERAPY, THE CLOT FORMED IS INVADED BY

CELLS FROMA: THE MARGINAL EPITHELIUMB: THE GINGIVAL CONNECTIVE

TISSUEC: THE BONE MARROW

D: THE PERIODONTAL LIGAMENT 7

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Aim of the periodontal therapy or Ideal outcome of therapy is New

Attachment with Bone regeneration

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Bone graft–associated new attachment.

Non–bone graft–associated new attachment

Combined approaches

RECONSTRUCTIVE TECHNIQUES

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• Bone grafting application of autogenous bone or other bone substitute obtained from natural or synthetic source to an area of with bony defect.

Transplanted osteogenesis :• Bone is dynamic and forms by cellular regeneration,

which produces osteoid that becomes mineralized.

• Bone grafting is accomplished through osteogenesis, osteoinduction and osteoconduction (Lane 1995, Frame 1987, Pinholt, Bang and Haanaes 1991, and Lancet 1992)

BONE GRAFT ASSOCIATED PROCEDURES

IDEAL PROPERTIES OF GRAFT MATERIALS

1. Biologic acceptability 2. Predictability3. Clinical feasibility 4. Minimal operative hazards 5. Minimal postoperative sequelae 6. Patient acceptance

BONE GRAFT MATERIALS ACT IN NUMBER OF WAYS

1. osteogenic, 2. osteoinductive, or 3. osteoconductive potential. Ostegenesis refers to the formation or development

of new bone by cells contained in the graft. Osteoinduction is a chemical process by which

molecules contained in the graft (bone morphogenetic proteins or BMPs) convert the neighboring cells into osteoblasts, which in turn form bone.

Osteoconduction is a physical effect by which the matrix of the graft forms a scaffold that favors outside cells to penetrate the graft and form new bone.

PROCEDURE

• All grafting techniques require presurgical scaling, occlusal adjustment as needed, and exposure of the defect with a full-thickness flap.

• The flap technique best suited for grafting purposes is the papilla preservation flap because it provides complete coverage of the interdental area after suturing.

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• All bone grafting materials have one or more of these three modes of action.

• Mixing of bone grafting substitutes can assist in bringing about a desired combination of modes of action for bone formation

• Because of making up the quantity of bone required in defects that definitely will benefit more from autogenous bone graft, any bone substitute can be mixed with autogenous bone graft to additionally effect all the mechanisms of action of bone regeneration attributed to autogenous bone graft.

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• Autogenous bone is suggested even when additional operating time and surgical site preparation is required when limiting factors exist.

• Osteogenesis, osteoinduction and osteoconduction are all positive mechanisms of bone regeneration with Osteogenesis being the fastest and most reliable.

• Bone substitute that regenerate bone via the osteoconductive mechanism are the least efficient.

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Patient SelectionDefect Selection

Graft Procurement and PreparationFlap Design and ReflectionSoft Tissue Debridement

Root PlaningIntramarrow Penetration

presuturingGraft Placement

Adequate condensation of graft materialFill to a realistic levelPeriodontal Dressing

Postoperative ManagementMaintenance

TECHNIQUE FOR PERIODONTAL BONE GRAFTING

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• should be in good physical health,• have a positive attitude toward therapy, • have repeatedly demonstrated an acceptable

level of plaque control, and• be committed to a periodontal maintenance

program.

PATIENT SELECTION

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• deep probing depths (greater than 7.0 mm) and bleeding on probing

• Clinical attachment loss over time also indicates the need for surgical intervention

• preoperative radiograph will usually confirm the presence of a vertical bone defect, depending on the location of the defect and thickness of the alveolar cortical plate

• A minimal amount of gingival recession is a positive factor for successful therapy.

DEFECT SELECTION

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• If the patient has sufficient donor sites, an intraoral bone autograft is the material of first choice.

• The obtained autogenous bone is placed in a sterile receptacle, such as a Dappen dish, and covered with saline -moistened gauze to prevent dehydration until the defect is prepared for graft insertion.

GRAFT PROCUREMENT AND PREPARATION

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Bone from intraoral sites – Healing extraction wounds Edentulous ridges Bone trephined from within the jaw without damaging root Newly formed bone Bone removed during osteoplasty and ostectomy

•Osseous coagulum •Bone blend •Intraoral cancellous bone marrow transplant•Bone swaging

AUTOGENOUS BONE GRAFTS

Sources of bone include bone from • healing extraction wounds, • bone from edentulous ridges, • bone trephined from within the jaw without damaging

the roots• newly formed bone in wounds especially created for the

purpose, bone removed during osteoplasty and ostectomy

Osseous coagulum • By Robinson 1969• Mixture of bone dust and blood• Small particles ground from cortical bone• A number 6 or 8 round carbide bur, rotating at 5000 to 30000 rpm, without

irrigation, produces bone dust which when coated with blood makes an osseous coagulum.

Sources:• Lingual Ridges on mandible• Exostoses• Edentulous ridges• Bone distal to last tooth

Advantage of particle size- It provides additional surface area for the interaction of cellular and vascular elements

Disadvantage:• Relatively low predictability• Inability to procure adequate material for large defects

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Bone Blend•Diem et al in 1972

SourcesExtraction socketExostosisEdentulous area Bone removed

triturated in capsule

workable plastic

mass packed into bony defect

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• Involves a green stick fracture of bone brdering an intra bony defect and the displacement of the bone to eliminate the ossseous defect.

• Presence of edentulous area adjacent to defect from which bone is pushed into contact with the root surface without fracturing the bone at the base.

BONE SWAGING/CONTIGUOUS AUTOGENOUS TRANSPLANT

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Bone Source –i. Maxillary tuberosityii. Edentulous areas iii. Healing socket

• Ridge incision made distal to last molar Bone removed with curved and cutting ronger

• Maxillary tuberosity – Assess in the radiograph to avoid sectioning of tendons of palatine muscle

• Edentulous ridges can be approached with a flap, and cancellous bone and marrow are removed with curettes, back-action chisels or trephine

INTRAORAL CANCELLOUS BONE MARROW TANSPLANTS

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• Blay et al. (2003).-technique based on the use of bone collectors for obtaining autogenous bone material, which allowed us to fill small bone defects, such as fenestrations and dehiscences, without having to involve a second (intraoral or extraoral) surgical area for obtaining autogenous bone.

• Piezoelectric device (Piezosurgery) was introduced for different bone augmentation procedures.

• Advantages:• Modulated ultrasound microvibrations (29 kHz, ranging

from 60 to 200 Hz) which should prevent damages to the adjacent soft tissues during osteotomy procedures. (Chiriac et al. 2005).

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• Bone grafts were obtained from 12 sedated miniature pigs. • bone grafts were obtained from the lateral portion of the

mandible during each harvesting technique• Each graft site was subdivided into four sections for collecting

cells using four different techniques:• Corticocancellous block grafts were harvested with a 6 mm trephine and

ground to particulate Bone chips using a bone mill.

• Bone chips were harvested with a sharp bone scraper.• Bone particles were collected with a bone trap filter from the suction tip

after drilling of cortical bone with a 2.2 mm round bur under saline conditions (bone slurry).

• Bone particles were harvested with a piezosurgery device under saline conditions.

THE IMPACT OF FOUR HARVESTING TECHNIQUES ON THE CELL VIABILITY AND OSTEOGENIC BEHAVIOUR OF CELLS IN

AUTOGENOUS BONE GRAFTS: A CRITICAL APPRAISAL OF AN EXPERIMENTAL STUDY (MIRON RJ 2012)

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• Cell viability was determined according to an immunoassay of released signalling molecules and gene expression that affect bone formation and resorption.

• The osteogenic activity of conditioned graft-sampled media was assessed in a bioassay using isolated bone cells.

• Cells in autogenous bone grafts obtained by using a bone mill and a bone scraper showed a higher viability and a stronger osteogenic potential than those from piezosurgery and bone drilling (slurry).

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• If the patient does not have sufficient intraoral donor sites, a demineralized freeze-dried bone allograft is the appropriate substitute.

• Allograft is reconstituted with a solution of 50 mg of tetracycline per ml of sterile water.

• Rationale: addition of an antibiotic will provide a zone of antibacterial activity and have an anticollagenolytic effect during the critical stages of wound healing.

• Synthetic grafts are used when neither an autograft nor an allograft is feasible .

• It is suggested that bone replacement grafts be wetted with the patient’s own blood from the surgical site, rather than saturated with sterile water or saline, which may hinder vascular infiltration of the saturated particles.

BONE FROM EXTRAORAL SITESIliac Autografts

Commonly used by orthopedic surgeonsComplicationsInfectionExfoliation and sequestrationVarying rates of healingRoot resorptionRapid recurrence of the defectDisadvantages Increased patient expenseDifficulty in procuring the donor material

ALLOGRAFTS

• Bone allografts are commercially available from tissue banks. They are obtained from cortical bone within 12 hours of the death of the donor, defatted, cut in pieces, washed in absolute alcohol, and deep frozen.

• The material may then be demineralized, and

subsequently ground and sieved to a particle size of 250 to 750 mm and freeze dried. Finally, it is vacuum sealed in glass vials.

• The material is then treated with chemical agents or strong acids to effectively inactivate the virus, if still present. The risk of human immunodeficiency virus (HIV) infection has been calculated as 1 in 1 million to 8 million and is therefore characterized as highly remote

UNDECALCIFIED FREEZE-DRIED BONE ALLOGRAFT

(FDBA)

• osteoinductive graft.

• Laboratory studies have found that DFDBA has a higher osteogenic potential than FDBA and is therefore preferred

DECALCIFIED FREEZE-DRIED BONE

ALLOGRAFTS (DFDBA)

osteogenic potential Demineralization in cold, diluted hydrochloric acid exposes the components of bone matrix, closely associated with collagen fibrils, that have been termed bone morphogenetic protein

• DFDBA in periodontal defects results in significant probing depth reduction, attachment level gain, and osseous regeneration

• The combination of DFDBA and guided tissue regeneration has also proven very successful

• A bone-inductive protein isolated from the extracellular matrix of human bones, termed osteogenin, has been tested in human periodontal defects and seems to enhance osseous regeneration

CASE-1 (USE OF DFDBA & POROUS HYDROXYAPATITE) FACIAL VIEW OF DEEP VERTICAL LESIONS MESIAL AND

DISTAL TO LOWER FIRST MOLAR, EXPOSED BY FLAP AND DEBRIDEMENT.

LINGUAL VIEW

FACIAL VIEW OF LESIONS FILLED WITH DFDBA (MESIAL DEFECT) AND POROUS

HYDROXYAPATITE (DISTAL DEFECT)

LINGUAL VIEWS

FACIAL VIEWS OF REENTRY AT 6 MONTHS POST-OPERATIVELY, SHOWING TOTAL FILL OF DISTAL

DEFECT AD PARTIAL FILL OF MESIAL DEFECT

LINGUAL VIEW

PREOPERATIVE RADIOGRAPH

RADIOGRAPH IMMEDIATELY AFTER PLACEMENT OF

GRAFT

PRE & POST OPERATIVE RADIOGRAPH(AFTER 6 MONTHS)

XENOGRAFTS

• Calf bone (Boplant), treated by detergent extraction, sterilized, and freeze dried, has been used for the treatment of osseous defects.

• Kiel bone is calf or ox bone denatured with 20% hydrogen peroxide, dried with acetone, and sterilized with ethylene oxide.

• Anorganic bone is ox bone from which the organic material has been extracted by means of ethylenediamine; it is then sterilized by autoclaving.

• These materials have been tried and discarded for various reasons; they are mentioned here to provide a historical perspective.

• Recently Yukna and co-workers have used a natural, anorganic, microporous, bovine-derived hydroxyapatite bone matrix, in combination with a cell binding polypeptide that is a synthetic clone of the 15 amino acid sequence of type I collagen.

• The addition of the cell binding polypeptide was shown to enhance the bone regenerative results of the matrix alone in periodontal defects

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PACKING OF THE PARTICLES

•When granules have uniform dimensions, dense packing will still leave space between the particles.

•With a wider size range, smaller particles fill up the spaces in between the larger particles.

•Such a granular mixture will extensively fill a defect space and leave very little room for tissue infiltration and regeneration

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• Accomplished by proper defect debridement.

• If the defect walls are relatively dry, and/or glistening, healing may be enhanced by intramarrow penetration to encourage bleeding and allow the ingress of reparative cells, vessels and other tissues.

Presuturing

• Loose placement of sutures, left untied, prior to the filling of the defect reduces the possibility of displacing the bone replacement graft during the suturing process.

PROMOTION OF A BLEEDING SURFACE

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• Graft material should be placed in small increments- • Gently packed into the angles and base of the defect with small

pluggers or curettes.

• Sterile plastic or Teflon-lined amalgam carriers are used to place the material and

• Sterile amalgam squeeze-cloths to use over the suction tip to dry the defect without removing any of the bone replacement graft material.

• After each increment of graft material is placed, it is blotted with saline-moistened gauze to absorb excessive blood and fluid.

• A slight overfill approach may be used with the understanding that excessive graft material will impede flap closure.

ADEQUATE CONDENSATION OF GRAFT MATERIAL

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• Defects should be filled with the bone replacement grafts only to the level of the defect walls.

• Overfilling with these materials may results in supracrestal bone formation.

• Overfilling may actually be counterproductive in that it may preclude proper flap closure, thereby retarding healing and possibly resulting in loss of the graft material.

FILL TO A REALISTIC LEVEL

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• Firm, protective periodontal dressing for ten days following bone replacement graft surgery is suggested.

• An antibiotic ointment under the dressing to help seal the area may be useful.

• Factors that jeopardize the success of treatment and make the use of protective dressings preferable.

possible impingement of foreign materials into the graft site,

flap displacement loss of the bone replacement graft material

PERIODONTAL DRESSING

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Removal of the junctional and pocket epithelium; Prevention of their migration into the healing area

after therapy Biomodification of the root surface

Clot stabilization, wound protection, and space creation

Guided tissue regeneration Biologic mediators (growth factors)

Stem cells Gene therapy

Scaffolding matrices

NON BONE GRAFT ASSOCIATED PROCEDURES

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The presence of junctional and pocket epithelium has been perceived as a barrier to successful therapy.

Methods:Curettage

Chemical agents Ultrasonics,

Lasers, Surgical techniques.

REMOVAL OF THE JUNCTIONAL AND POCKET EPITHELIUM

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REMOVAL OF JNCTIONAL AND POCKET EPITHELIUM

A. Surgical removal by curettage Results of removal of epithelium by means of curettage vary from complete removal to persistence of as much as 50% It therefore is not a reliable procedure. Ultrasonic methods and rotary abrasive stones have also been used, but their effects cannot be controlled because of the clinician's lack of tactile sense when using these methods

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CHEMICAL AGENTS

• Chemical agents have also been used to remove pocket epithelium , in most cases in conjunction with curettage.

• The most commonly used drugs have been sodium sulfide, phenol camphor, antiformin, Sodium hypochlorite. Disadvantage• However, the effect of these agents is not limited to the

epithelium, and their depth of action cannot he controlled. They are mentioned here for their historical interest.

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SURGICAL TECHNIQUES

1 ENAP2 Gingivectomy3 Modified Widman Flap4 Coronal displacement of the flap

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ENAP, GINGIVECTOMY

ENAP: Excisional new attachment procedure The excisional new attachment procedure consists of an internal bevel incision performed with a surgical knife, followed by removal of the excised tissue. No attempt is made to elevate a flap. After careful scaling and root planing, interproximal sutures are used to close the wound

Glickman and Prichard have advocated performing a gingivectomy to the crest of the alveolar bone and debriding the defect.

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MODIFIED WIDMAN FLAP

The modified Widman flap, as described by Ramfjord and Nissle, is similar to the excisional new attachment procedure but is followed by elevation of a flap for better exposure of the area It eliminates the pocket epithelium with the internal bevel incision

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CORONAL DISPLACEMENT OF

THE FLAP

• Another approach to delaying epithelial migration into the healing pocket area has been the use of coronal displacement of the flap, which increases the distance between the epithelium and the healing area.

• This technique is particularly suitable for the treatment of lower molar furcations and has been used mostly in conjunction with citric acid treatment of the roots

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Elimination of the junctional and pocket epithelium may not be sufficient because the epithelium from the excised margin may rapidly proliferate to become interposed between the healing connective tissue and the cementum.

Total removal of the interdental papilla covering the defect and its replacement with a free autogenous graft obtained from the palate.

Coronally displaced flaps, which increase the distance between the epithelial wound edge and the healing area.

Guided Tissue Regeneration

PREVENTION OR IMPEDING THE EPITHELIAL MIGRATION

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Method for the prevention of epithelial migration along the cemental wall of the pocket and maintaining space for clot stabilization is a technique called guided tissue regeneration (GTR).

This method is derived from the classic studies of Nyman, Lindhe, Karring, and Gottlow .

Based on the assumption that only the periodontal ligament cells have the potential for regeneration of the attachment apparatus of the tooth.

GTR consists of placing barriers of different types (membranes) to cover the bone and periodontal ligament, thus temporarily separating them from the gingival epithelium and connective tissue.

GUIDED TISSUE REGENERATION

• The initial membranes developed were nonresorbable and therefore required a second operation to remove it.

• This second operation was done after the initial stages of healing, usually 3 to 6 weeks after the first intervention.

• This second operation was a significant obstacle in the utilization of the procedure, and therefore resorbable membranes were developed.

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1st Generation - Non ResorbableGore-Tex

2nd Generation – ResorbableBiomend

Resolute

Capset

Atrisorb

3rd Generation - Resorbable & AntimicrobialAtrisorb - D

GTR MEMBRANES

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GTR/GBR membranes are divided into two groups, nonresorbable and resorbable, according to their degradation characteristics.

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Studies by Gottlow & Cortenelli indicate that e-PTFE may support significant amounts of periodontal regeneration( up to 6.8mm) in intrabony defects in histological sections at 3-6 months healing interval.

Pontoriero et al reported results in grade II furcations treated with E-PTFE 90% showed complete resolution as compared to only 20% in control group.

Studies using e-PTFE show a bone fill of 3.0mm to 5.0mm with / without graft material in intrabony defects, with 3-walled defects responding the best. These results are sustained for min of 5 yrs (Handlesman M, Celleti R, and Becker et al )

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Clinical trials using bovine type-1 collagen in intrabony defects have shown results comparable to that of non resorbable membranes; Blumenthal et al,1988, Bowers 1989, Chung & PiniPrato 1993.

Yukna & Yukna 1996; reported no difference with usage of collagen or e-PTFE in treatment of furcation defects.

Blumenthal 1990; Intrabony defects combination of collagen and bone graft1:1resulted in formation of well organized PDL and new bone.

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• The critical disadvantages of both PTFE-based nonresorbable (e.g., second surgery) and Resorbable membranes, mainly those based on collagen (e.g., insufficient mechanical properties, unpredictable degradation profiles), have led to studies of alternate membrane materials.

• Research groups have been investigating the possibility of using membranes with a functionally graded structure to maintain sufficient mechanical properties during service, predictable degradation rate, and bioactive properties.

• Bone formation would be stimulated by calcium–phosphate based nanoparticles or growth factors (e.g., BMP-2, TGF-, among others) on the hard tissue/membrane interface and

• Bacterial colonization would be inhibited by antibacterial drugs delivered at the soft tissue/membrane interface

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ELECTROSPINNING (E-SPINNING) FOR MEMBRANES

Formhals first introduced electrospinning or e-spinning in 1938

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e-spun membranes showed • a high surface area of improved hydrophilicity and wettability, • endow the structure with mechanical support and • regulate cell functions guiding new bone formation into the defect.

Li et al. have cultured different cells such as fibroblasts, cartilage cells, and mesenchymal stem cells on PLGA and PCL nanofibrous e-spun scaffolds and

demonstrated the ability of the nanofiber structure to support cell attachment and proliferation.

Because of the inherent high surface area, surface functional groups, interconnected pores and nano-scaled size, nanofiberbased scaffolds are more favorable than micro-fibers or any other morphological forms.

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While GTR is unique in its use as a membrane, the surgical procedure is same as flap debridement for regeneration.

Complete debridement and postoperative plaque control mandatory.

Most critical- Complete primary closure. Essential to preserve as much gingival tissue as possible to ensure barrier coverage.

Hence flap design and suture technique require special consideration for primary closure according to particular situations

SURGICAL TECHNIQUE/PROCEDURE

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Surgical procedure for GTR:-Modified papilla preservation flapSimplified papilla preservation flapPapilla amplification flap procedure

The main objective here is to obtain complete membrane closure.

Full thickness flap with preservation of as much of the interdental papilla as possible followed by through debridement.

Management of root and bone surface: Root surface detoxification.

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The ePTFE membrane (nonresorbable) can be obtained in different shapes and sizes to suit proximal spaces

and facial/lingual surfaces of furcations

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• Raise a mucoperiosteal flap with vertical incisions,extending a minimum of two teeth anteriorly and one tooth distally tthe tooth being treated.

• Debride the osseous defect and thoroughly plane the roots.

• Trim the membrane to the approximate size of the area being treated.

• Apical border of the material should extend 3 to 4 mm apical to the margin of the defect ,

• Laterally 2 to 3 mm beyond the defect,• Occlusal border of the membrane should be placed 2 mm apical to

the cementoenamel junction.

TECHNIQUE

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• Suture the membrane tightly around the tooth with a sling suture.

• Suture the flap back in its original position or slightly coronal to it, using independent sutures interdentally and in the vertical incisions. The flap should cover the membrane completely.

• The use of periodontal dressings is optional, and the patient is placed on antibiotic therapy for 1 week.

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Selection and placement of membrane

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In e-PTFE, do not remove the open microstructure-trim laterally

Proper adaptation of membrane

In either periodontal or bony ridge defects, the amount of space beneath the membrane determines maximum potential regeneration, Without space maintainence, regeneration is not possible.

Interproximal defects barriers require special handling during placement. The barrier is folded in half allowed to pass through interproximally beneath the interdental contacts, or it can be passed directly through the contacts if they are open.

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Suturing of membrane

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The flaps should be sutured with the remaining material using slight tension to ensure interproximal closure.

Vertical mattress sutures are commonly used to minimize the amount of suture beneath the flap to help draw the flaps coronally.

When using an osseous graft, it is preferable to pre-suture the flap.

SUTURING THE FLAPS

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Post operative care is critical in the success of GTR procedures.

It is particularly important to see the patient frequently while the barrier is in place.

Weekly visits may be desirable. Chlorhexidine mouthwash for initial 2 weeks is recommended to augment the oral hygiene.

Doxycycline and amoxicillin are common choices for 7- 10 days.

POSTOPERATIVE REGIME

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• The initial membranes developed were nonresorbable and required a second surgical procedure to remove them.

• This second procedure was accomplished after the initial stages of healing, usually 3 to 6 weeks after the first intervention.

REMOVAL OF MEMBRANE

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Removal of membrane

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TO BE CONTD…..

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PART 1Introduction

Bone graft associated proceduresNon Bone graft associated procedures

Removal of the junctional and pocket epithelium

Prevention of their migration into the healing area after therapy

CONTENTS

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PART 2• Biomodification of the root surface• Biologic mediators (growth factors)

• Gene therapy• Combined techniqes

• Evidence based practice perspective• Conclusion• References

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ROOT SURFACE BIOMODIFICATION

(Garrett 1977)Removal of bacterial deposits, calculus, and endotoxins from the cementum is generally considered essential for the formation of a new connective attachment

Stahl et al. (1972) demineralization of the root surface, exposing the collagen of the dentin, would facilitate the deposition of cementum by inducing mesenchymal cells in the adjacent tissue to differentiate into cementoblasts.

The biologic concept is that exposure of collagen fibers of the dentin matrix may facilitate adhesion of the blood clot to the root surface and thereby favor migration of the fibroblasts.

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Mechanical –Scaling and root planing

Chemical –citric acid, fibronectin,tetracycline hydrochloride,laminin,EDTA.

Growth factors

Lasers

METHODS OF ROOT CONDITIONING

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CITRIC ACID

1. Accelerated healing and new cementum formation occur after surgical detachment of the gingival tissues and demineralization of the root surface by means of citric acid.

2. Topically applied citric acid on periodontally diseased root surfaces has no effect on nonplaned roots, but after root planing, the acid produces a 4-mm-deep demineralized zone with exposed collagen fibers

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3. Root-planed, non-acid-treated roots are left with a surface smear layer of microcrystalline debris; citric acid application not only removes the smear layer, exposing the dentinal tubules, but also makes the tubules appear wider and with funnel-shaped orifices.

4. Citric acid has also been shown in vitro to eliminate endotoxins and bacteria from the diseased tooth surface.

5. An early fibrin linkage to collagen fibers exposed by the citric acid treatment prevents the epithelium from migrating over treated roots.

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Recommended citric acid technique is as follows:

Raise a mucoperiosteal flap and thoroughly instrument the root surface, removing calculus and underlying cementum.

Apply cotton pledgets soaked in a saturated solution of citric acid (pH of 1.0) for 2 to 5 minutes.

Remove pledgets, and irrigate root surface profusely with water.

Replace the flap and suture.

FIBRONECTIN• Fibronectin is the glycoprotein that fibroblasts require to

attach to root surfaces. The addition of fibronectin to the root surface may promote new attachment .

• However, increasing fibronectin above plasma levels produces no obvious advantages.

• This material is commercially available as Tissucol. It is a biologic mediator that enhances the tissue response in the early phases of wound healing, prevents separation of the flap, and favors hemostasis and connective tissue regeneration.

TETRACYCLINE

• In vitro treatment of the dentin surfaces with tetracycline increases binding of fibronectin, which in turn stimulates fibroblast attachment and growth while suppressing epithelial cell attachment and migration.

• It also removes an amorphous surface layer and exposes the dentin tubules.

• A human study showed a trend for greater connective tissue attachment after tetracycline treatment of roots.

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• New connective tissue attachment following citric acid demineralization of root surfaces has been demonstrated histologically in humans (Cole et al. 1980)

• Results from clinical trials indicate no additional improvement in clinical conditions when citric acid treatment is used in conjunction with surgical procedures, either without(Kersten BG1992, Moore JA 1987) or in combination with osseous grafts (Renvert S 1985) or GTR techniques

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• Attempts to combine root surface demineralization and fibronectin to induce a more significant regenerative response have shown promise during in vitro experimentation(Terranova VP et al 1986)

• More recent studies (Blomlof J1996, 1997 )indicate that the use of materials with a less acidic pH, e.g., EDTA, may also expose collagen fibers, thus promoting cell attachment, without having a damaging effect on the surrounding tissues.

• However, when used in humans, this technique did not provide significant clinical improvements

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• Biomodification of root surface with enamel matrix protein during surgery ,following demineralization with EDTA has been introduced.

• Based on the biological concept that the application of enamel matrix protein may promote periodontal regeneration as it mimics events that takes place during the development of periodontal tissues.

ENAMEL MATRIX PROTEINS

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Described by Mellonig.

Raise a flap for reconstructive purposes

Remove all granulation tissue and tissue tags, the root surface should be thoroughly planed.

Completely control bleeding within the defect.

Demineralize the root surface with citric acid (pH of 1.0), or preferably with 24% ethylenediaminetetraacetic acid (EDTA Biora) (pH of 6.7) for 15seconds. This removes the smear layer and facilitates adherence of the Emdogain.

TECHNIQUE

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Rinse the wound with saline, and apply the gel to completely cover the exposed root surface. Avoid contamination with blood or saliva.

Complete closure of the wound is necessary, therefore a well-designed flap and suturing technique is mandatory.

If adequate closure cannot be obtained, correct the scalloping of the gingival margin or slight osteoplasty may be necessary.

A periodontal dressing is preferred to protect the wound.

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The evidence does not demonstrate an inductive role of EMPs on cementogenesis.

Specific small amelogenin polypeptides (5 kDa) have osteoinductive properties when tested in an ectopic bone-forming model.

EMPs have biological effects on cells of the osteoblast lineage including upregulation of markers of bone formation.

EMPs increase cell proliferation of PDL and gingival fibroblasts and cells of osteoblast and chondrocyte lineage.

BIOLOGICAL MEDIATORS AND PERIODONTAL REGENERATION: A REVIEW OF ENAMEL MATRIX PROTEINS AT THE CELLULAR AND

MOLECULAR LEVELS (BOSSHARDT 2008)CONSENSUS REPORT OF THE SIXTH EUROPEAN WORKSHOP ON

PERIODONTOLOGY

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Objectives:-To test whether EMD is effective, and to compare EMD versus GTR, and various Bone Graft procedures for the treatment of intrabony defects.

A meta-analysis including nine trials showed that EMD treated sites displayed statistically significant Periodontal Attachment Level improvements (mean difference 1.1 mm, 95% CI 0.61 to 1.55) and PPD reduction (0.9 mm, 95% CI 0.44 to 1.31)

ENAMEL MATRIX DERIVATIVE (EMDOGAIN) FOR PERIODONTAL TISSUE REGENERATION IN INTRABONY DEFECTS. A COCHRANE

SYSTEMATIC REVIEW.( ESPOSITO M 2009)

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One year after its application, EMD significantly improved PAL levels (1.1 mm) and reduced PPD (0.9 mm) when compared to a placebo results have to be into contro

With the exception of significantly more postoperative complications in the GTR group, there was no evidence of clinically important differences between GTR and EMD.

Bone substitutes may be associated with less Recession than EMD.

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Aim :- updated answer to the question of whether the additional use of EMD in periodontal therapy is more effective compared with a control or other regenerative procedures.

PERIODONTAL REGENERATION WITH ENAMEL MATRIX DERIVATIVE IN RECONSTRUCTIVE PERIODONTAL THERAPY: A

SYSTEMATIC REVIEW. KOOP R, MERHEB J, QUIRYNEN M.(2012)

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In the treatment of intrabony defects,the use of EMD is superior to control treatments but as effective as resorbable membranes.

The additional use of EMD with a coronally advanced flap for recession coverage will give superior results compared with a control but is as effective as a connective tissue graft.

The use of EMD in furcations will give more reduction in horizontal furcation defect depth compared with resorbable membranes.

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NON-BIOABSORBABLE VS. BIOABSORBABLE MEMBRANE: ASSESSMENT OF THEIR CLINICAL EFFICACY IN GUIDED

TISSUE REGENERATION TECHNIQUE. A SYSTEMATIC REVIEW.(PARRISH LC 2009)

Conclusion:-Non-bioabsorbable membranes without graft material, collagen membranes with graft material, and EMD with or without graft material were all found to be superior to OFD with or without graft material.

In addition, polylactic acid derivatives without grafts were found to be superior to OFD without grafts, and non-bioabsorbables without graft material were found to be superior to collagen without graft material

The purpose of the present research was to expand on that work, particularly searching for trends discriminating between bioabsorbable and non-bioabsorbable barriers, as well as the use of enamel matrix derivative, with respect to interproximal bony defects.

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Aim:- to investigate whether enamel matrix derivatives (EMD) in conjunction with other regenerative materials yield better treatment outcomes than EMD alone in the treatment

of infrabony defects > or =3 mm.

DO BONE GRAFTS OR BARRIER MEMBRANES PROVIDE ADDITIONAL TREATMENT EFFECTS FOR

INFRABONY LESIONS TREATED WITH ENAMEL MATRIX DERIVATIVES? A NETWORK META-ANALYSIS OF RANDOMIZED-CONTROLLED TRIALS.(TU YK 2010)

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Twenty-eight studies were included in the review. EMD plus bone grafts and EMD plus membranes attained 0.24 mm [95% high probability density (HPD) intervals: -0.38, 0.65] and 0.07 mm (95% HPD intervals: -1.26, 1.04) more PPD reduction than EMD alone, respectively. For CAL gain, EMD plus bone grafts and EMD plus membranes attained 0.46 mm (95% HPD intervals: -0.17, 0.83) and 0.15 mm (95% HPD intervals: -1.37, 0.30), respectively.

When different types of bone grafts and barrier membranes were treated separately, EMD with bovine bone grafts showed greater treatment effects.

Conclusion:-There was little evidence to support the additional benefits of EMD in conjunction with other regenerative materials.

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• Aims: Guided tissue regeneration (GTR) and enamel matrix derivatives (EMD) are two popular regenerative treatments for periodontal infrabony lesions. Both have been used in conjunction with other regenerative materials.

• A total of 53 studies were included in this review, and we found small differences between regenerative therapies which were non-significant statistically and clinically.

A BAYESIAN NETWORK META-ANALYSIS ON COMPARISONS OF ENAMEL MATRIX DERIVATIVES, GUIDED TISSUE

REGENERATION AND THEIR COMBINATION THERAPIES. (TU Y-K 2012)

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GTR and GTR-related combination therapies achieved greater PPD reduction than EMD and EMD-related combination therapies.

Combination therapies achieved slightly greater CAL gain than the use of EMD or GTR alone.

GTR with BG achieved greatest defect fill.

Conclusion: Combination therapies performed better than single therapies, but the additional benefits were small.

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• Attempts with bone Grafting substitutes have resulted in some regeneration, but this is usually limited to the base or apical aspect of the defect and the resultant tissue formation is not sufficient in terms of quantity or predictability.

For these reasons, new therapeutic approaches for periodontal regeneration have been sought.

One way to stimulate these cells is to use proteins (growth factors) that can bind to surface receptors on the cell

membranes,

which in turn trigger a series of events to occur that alter the genetic activity of the cell with the result that cell behavior is

stimulated

BIOLOGIC MEDIATORS

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• Most growth factors stimulate one of two cell behaviors:

Cellular proliferation (cell division and an increase in the number of cells)

Cellular differentiation (the cells produce terminal products [e.g., fibroblasts produce collagen and osteoblasts produce bone])

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To be effective as a therapeutic agent:• GF has to reach the site of injury without degradation,and

then,it has to remain in the target location sufficiently long to exert its action(s).

• GFs that are provided exogenously in solution into the site to be regenerated are generally not effective

• GFs tend to diffuse away from wound locations and are enzymatically digested or deactivated

• It also includes the loss of bioactivity, low availability due to their relatively large size and slow tissue penetration, and toxicity due to excess concentration of GFs

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There is increasing evidence that enabling GFs to exert their

biological function efficiently in tissue engineering

requires the design and development of release technologies that provide controlled spatio temporal

delivery of key signalling molecules and prevent unwanted and potentially harmful side-effects.

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• Controlled GF delivery systems for wound healing should be designed to deliver multiple soluble proteins at different rates and potentially in a different spatial orientation to mimic the native developmental environment as closely as possible

• Controlled delivery is the process of delivering certain molecules at a determined rate to achieve prolonged availability in addition to providing protection for a bioactive agent that might otherwise be rapidly metabolised. (GPT 10)

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• Wound healing is a complex process that involves several overlapping stages including inflammation, formation of granulation tissue,

re epithelialization, matrix formation and remodeling.

• This healing cascade is executed and regulated by an equally complex signaling network that involves numerous GFs, cytokines and chemokines.

REQUIREMENTS FOR MULTIPLE GROWTH

FACTORS

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• To perform a systematic review of human studies using growth factors for periodontal regeneration and to compare the efficacy of these growth factors to other accepted techniques for periodontal regeneration.

• Histologic evidence demonstrated greater periodontal regeneration when using growth factors compared to other regenerative techniques and an increased healing and bone maturation rate compared to other regenerative and bone augmentation techniques in these human studies.

A SYSTEMATIC REVIEW OF THE USE OF GROWTH FACTORS IN HUMAN PERIODONTAL

REGENERATION. (DARBY IB 2013)

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The use of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) led to greater clinical attachment level gain of 1mm compared to an osteoconductive control, b-tricalcium phosphate (b-TCP).

The use of rhPDGF-BB led to greater percentage bone fill of 40% and bone growth of 2mm compared to the osseoconductive control, b-TCP.

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• Topical administration of GFs has displayed some potential in wound healing, but their implementation has been hampered by variable efficacy ,high doses, and high costs.

• Gene therapy ignores the fact that wound repair is driven by interactions between multiple GFs and ECM proteins.

• Polymer processing techniques often involve high temperatures and organic solvents, which may induce a change in the encapsulated protein’s structural conformation and thus result in inactivity .

GENE THERAPY

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Therapeutic gene delivery involves delivering specific genes to a target tissue with the goal of converting the recipient cells in to protein producing factories, thus producing physiological levels of endogenous GFs of interest to enhance the regeneration of specific tissues .

The transfer of a therapeutic gene can cure a disease or offer the transient advantage of tissue growth and regeneration; the underlying virtue of the latter is that gene therapy provides the opportunity to manipulate both local and systemic GFs

Many factors must be considered when planning gene therapy as an indirect GF delivery approach to tissue regeneration at a wound site, particularly when delivering multiple GFs

First,the gene should be chosen for the protein that is thought to most efficiently direct specific tissue regeneration. The secretion of multiple gene products that have synergistic effects on tissue regeneration can be accomplished by delivering multiple genes or by introducing a gene that activates simultaneous synthesis of multiple GFs

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• Gene therapy can be performed either by 1. directly introducing the delivery vector in to the anatomic

site(in vivo) 2. by harvesting cells from the patient,transferring the

gene(s) to the cells in tissue culture,and then transferring the genetically modified cells back in to the patient(ex vivo)

• The in vivo approach can be accomplished either by direct injection in to the site or by attaching the delivery vector to the scaffold.

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• A biomaterial device that can serve as a vehicle for gene delivery as well as a scaffold for cell delivery and subsequent penetration and ingrowth is the best choice

• The method of gene delivery must be determined for a specific application.

• Vectors for gene delivery can be viral or non-viral

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• Froum et al have analyzed the criteria that should guide the choice of treatment technique

Clinical results depend on • Dimension and morphology of the defect (deeper lesions result in

greater bone fill than shallower defects), • Number of walls in the defect (threewall defects have greater

potential to fill than two-wall or one-wall defects), • Amount of root surface exposed and the ability to obtain adequate

flap coverage and • Angle of the defect to the long axis of the tooth(the smaller the

angle, the better chance of success).

COMBINED TECHNIQUES

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• On the basis of these criteria, Froum et al established the clinical decision tree:

For Deep, Well-Contained Defect• Use EMD alone, with a coronally advanced flap

For Moderate to Deep, Noncontained Defects• Use EMD + graft, with a coronally advanced flap (if necessary).

For Supracrestal Defects with a Shallow Vertical Defect• Use EMD + graft + barrier membrane, with a coronally advanced

flap.

• The combination of barrier techniques with bone grafts

• 1. Perform a regenerative type flap. If recession has occurred and/or coronal flap positioning is required for membrane coverage, periosteal separation is performed.

• 2. The defect is debrided of all granulation tissue and the root surface is planed to remove all remnants of plaque, accretions and other root surface alterations (grooves, notches, caries) employing ultrasonic/ sonic, hand, and/or rotary instrumentation.

3. Odontoplasty and/or osteoplasty are performed if required for adequate access to the defect including intraradicular or furcation fundus concavities and/or reduction of enamel projections.

4. The bone graft (typically DFDBA) is prepared in a dappen dish, hydrating it with sterile saline or local anesthetic solution, and if there is no contraindication, is combined with tetracycline (125 mg/0.25 g of DFDBA). After mixing, the dappen dish is covered with a sterile, moistened gauze to prevent drying of the graft. .

5. The appropriate membrane (usually ePTFE) is selected and trimmed to fit the desired position and placed on a sterile gauze. Care is taken to prevent contamination by contact with soft tissues or saliva.

6. The area is thoroughly cleansed and isolated, and the regenerative site root surface is treated with cotton pellets soaked in citric acid pH 1 for 3 minutes, taking care that the solution does not go beyond the root and bone surface. The pellets are removed and the site inspected for any residual cotton fibers prior to flushing the site with sterile water or saline.

7. If a sclerotic bone surface exists in the graft site, intramarrow penetration is performed with a round bur.

8. The ligament surface is "scraped" with a periodontal probe to remove any eschar and stimulate bleeding.

9. The DFDBA is packed firmly in the defect using an overfill approach, covering the root trunk and combination or confluent vertical dehiscence or horizontal osseous defects.

10. The custom-fitted membrane is placed over the graft and secured as appropriate.

11. The area is rechecked to ensure that adequate graft material remains in the desired area, and the flap is positioned to cover the membrane and secured with nonabsorbable sutures.

12. A periodontal dressing is passively applied over the surgical area, with Surgicel covering the sutures.

• Typical pre- and postoperative medication regimens include, if not contraindicated, 7 to 10 days of antibiotic coverage, which is subsequently extended with doxycycline, 100 mg daily for 2 to 7 weeks; steroid therapy such as methylprednisolone and analgesic agents

FACTORS INFLUENCING A SUCCESSFUL OUTCOME• Inadequate plaque control• Poor compliance with supportive periodontal therapy• Smoking• Other factors such as flap design, defect and root

morphology, material employed, flap position, and post operative management

COMBINED TECHNIQUECASE PRESENTATION(GTR & BONE GRAFT) PRETREATMENT PHOTOGRAPH OF LOWER LEFT

POSTERIOR TEETH WITH MARKED RECESSION AND TISSUE INFLAMMATION

UNDERLYING EXTENSIVE CRESTAL BONE LOSS, DEHISCENCE, AND INTRABONY

OSSEOUS DEFECTS

BONE GRAFT IN POSITION APPROXIMATING THE CEMENTOENAMEL

JUNCTION OF POSTERIOR TEETH

BARRIER MEMBRANES OVER THE BONE GRAFTS

FLAPS CORONALLY POSITIONED AND SECURED OVER THE BARRIER

MEMBRANES

MEMBRANE REMOVAL REVEALING NEW ALVEOLAR BONE

PRE AND POST TREATMENT RADIOGRAPH(AFTER 1 YEAR)

CASE- COMBINED TECHNIQUE(DFDBA & EPTFE) FACIAL ASPECT OF TOOTH WITH 9

MM POCKET

MESIAL ONE-WALL/HEMISEPTAL INTRABONY DEFECT AND FACIAL DEHISCENCE OSSEOUS

DEFECT EXPOSED AND SITE DEBRIDED

DFDBA IN POSITION

BARRIER MEMBRANCE (EPTFE) OVER BONE GRAFT

APPEARANCE OF NEW TISSUE AT TIME OF MEMBRANE REMOVAL ( 6 WEEKS AFTER

SURGERY) SUGGESTIVE OF NEW ALVEOLAR BONE SLIGHTLY APICAL TO CEMENTOENAMEL

JUNCTION

PRE AND POST TREATMENT RADIOGRAPH (AFTER 2

YEARS)

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The goals of periodontal therapy include: • the reduction or elimination of tissue inflammation induced by

bacterial plaque and its by-products, • correction of defects or anatomical problems caused by the

disease process, • and regeneration of lost periodontal tissues as a consequence of

disease destruction.

CONCLUSION

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• Bone replacement grafts-adequate clinical and histologic evidence of bone fill and periodontal regeneration to recommend the use of bone replacement grafts in clinical practice.

• Guided tissue regeneration-particularly in 3-wall intrabony and gingival recession defects.

• less predictable, results in treating Class II furcation defects, particularly those involving mandibular teeth.

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• Root surface modification using demineralization -has shown variably favorable results that are not reliably reproducible in humans. Hence, the value of this approach in clinical practice remains limited.

• Growth factors and proteins- Histologic evidence demonstrated greater periodontal regeneration when using growth factors compared to other regenerative techniques

• Establishing a scientifically sound, evidence-based rationale is critical to the ultimate success of regenerative therapies.

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• Clinical Periodontology – Carranza -11th Edition

• Text Book Of Clinical Periodontology And Implant Dentistry- J. LINDHE - 5th EDITION

• Periodontal surgery-A clinical atlas –Sato.N

• Color atlas of periodontology. HM Wolf

• Periodontal Therapy-Clinical Approaches and Evidence of Success- Nevins.M

• Pellegrini G, Pagni G, Rasperini G. Surgical Approaches Based on Biological Objectives: GTR versus GBR Techniques. Int J Dent. 2013.

• Periodontal Regeneration. Position Paper. J Periodontol September 2005

• Rios HF, Lin Z, Oh B, Park CH, Giannobile WV. Cell- and gene-based therapeutic strategies for periodontal regenerative medicine. J Periodontol 2011 Sep;82(9):1223-37.

REFERENCES

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