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IMPLANTOLOGY PROGRAM (BASIC IMPLANTOLOGY ) SEMESTER 2 By Ass.Prof.Dr. Marwa Mohammed Tawfiq Associate professor of Ora...

IMPLANTOLOGY PROGRAM (BASIC IMPLANTOLOGY ) SEMESTER 2 By Ass.Prof.Dr. Marwa Mohammed Tawfiq Associate professor of Oral medicine and periodontology department – Beni-suef university Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  Periodontal Regeneration Ass. Prof Dr. marwa.M.Tawfiq Associate professor of Oral medicine &Periodontics Beni-suef University REGENERATIVE PERIODONTAL THERAPY Periodontal regeneration The reproduction or reconstitution of lost or injured part so that the form and function of lost structures are restored. The restoration of form and function of lost tooth supporting tissues during periodontal disease & this include regeneration of alveolar bone, cementum & periodontal ligament. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Periodontal repair  Healing that does not completely restore the architecture or function of the part. Periodontal repair is healing by a long junctional epithelium. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Reattachment (to attach again): The reunion of = (epithelial + New attachment connective tissue) with a root surface that has been mechanically  The union of connective tissue or surgically separated from each other. or epithelium with a root surface that has been deprived of its original attachment.  This new attachment may be epithelial adhesion and/or connective tissue adaptation or attachment which may include new cementum this usually occurs when attachment has been lost due to disease progression Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Classification of periodontal pockets Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU A- 3 wall defect B- 2-wall defect C- combination defect D- 1-wall defect Periodontal pocket produces destruction of the supporting periodontal tissues, thereby leading to the loosening and exfoliation of the teeth. The remainder of this chapter refers to this type of pocket. Two types of periodontal pockets exist, as follows: Pockets can involve one, two, or more tooth surfaces, and they can be of different depths and types on different surfaces of the same tooth and on approximal surfaces of the same interdental space.30,38 Pockets can also be spiral (i.e., originating on one tooth surface and twisting around the tooth to involve one or more additional surfaces) (Figure 20-3). These types of pockets are most Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU A- 3 wall defect B- 2-wall defect C- combination defect D- 1-wall defect Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Two types of periodontal pockets exist, as follows Pockets can involve one, two, or more tooth surfaces, and they can be of different depths and types on different surfaces of the same tooth and on approximal surfaces of the same interdental space. Pockets can also be spiral (i.e., originating on one tooth surface and twisting around the tooth to involve one or more additional surfaces). These types of pockets are most common in furcation areas Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Horizontal bone loss When the bone loss occurs on a plane that is parallel to a line drawn from the cementoenamel junction (CEJ) of a tooth to that of an adjacent tooth, it is called horizontal bone loss. It is Supra bony pockets one of the common patterns of bone loss in periodontal disease. The bone margin remains roughly perpendicular to the tooth surface intrabony pockets Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Suprabony (supracrestal or supraalveolar) occurs when the bottom of the pocket is coronal to the underlying alveolar bone Intrabony (infrabony, subcrestal, or intraalveolar) occurs when the bottom of the pocket is apical to the level of the adjacent alveolar bone. With this second type, the lateral pocket wall lies between the tooth surface and the alveolar bone Horizontal bone loss-------indicates an inflammatory process which exist over a long period of time Vertical bone loss------indicated more rapid bone resorption Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Three wall intrabony defects provide the best prognosis for regenerative technique. This is followed by the Two wall intrabony defects and intraosseous craters the availability of regenerative resources is greatly decreased in one wall intrabony defects Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Healing of three wallWound healing of a deep narrow three-wall intrabony defect is similar to healing of the intrabony defect: extraction socket. 1. Immediately after surgery, a blood clot fills the defect. 2. The clot and surrounding tissues contain growth factors, proteins and molecules necessary for normal wound healing. 3. Organization of the clot occurs within several days by proliferation of blood vessels and budding of delicate granulation tissues. 4. Epithelium from the wound margins begins to migrate over the clot at about 1 mm a day. 5. By the 21st day, osteogenic activity appears near the budding capillaries from the endosteum of the surrounding bone. 6. The socket is filled with woven and lamellar bone by 2 months. Calcification continues for additional weeks. 7. By six months, radiographs will demonstrate bone fill. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU In order to prepare for regeneration and new attachment, there are three critical areas to which treatment is applied: 1-The granulation tissue of the defect and the residual transeptal and periodontal fibres covering the bone (soft tissue). 2-The root surface. 3-The underlying bone. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  In order to prepare for regeneration and new attachment, there are three critical areas to which treatment is applied: 1-The granulation tissue of the defect and the residual transeptal and periodontal fibers covering the bone (soft tissue) With flaps reflected, large curettes are used against the bony surface to remove all granulation tissue and residual fibers attached to bone. Small curettes and ultrasonic instruments are used in the apical areas. All fibers must be removed to open the marrow spaces and permit intimate contact between graft material and bone. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU In order to prepare for regeneration and new attachment, there are three critical areas to which treatment is applied: 2. Root surface conditioning material Removal of bacterial deposits, calculus and endotoxin in the cementum is essential for formation of new connective tissue attachment. it has been found that demineralization of the root surface, exposing the collagen of the dentin would facilitate the deposition of cementum and so supports regeneration of periodontal attachment. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU In order to prepare for regeneration and new attachment, there are three critical areas to which treatment is applied: 3. bone : decortification is performed. Decortification is the formation of small holes in the bone with sharp curettes or small round bur. This permits: − Rapid proliferation of granulation tissue with undifferentiated mesenchymal cells. − Rapid regeneration of bone. − Rapid union of graft and bone substances used for root surface conditioning. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Periodontal regeneration procedures include: 1. Grafting procedures. 2. Guided tissue regeneration (GTR). 3. Root conditioning and biomodification. 4. Biologic mediators for periodontal regeneration (Emdogain). 5. Combination of any of the previous procedures. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Grafting materials could be: Osteoinductive bone formation is induced in the surrounding soft tissues immediately adjacent to the grafted material i.e. the graft material induces the neighbouring tissue to form bone through the action of factors contained within the grafted bone such as proteins or growth factors. Osteoconductive: Which means that the grafted material does not contribute to new bone formation but serves as a scaffold or frame for new bone formation originating from adjacent host bone. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Osteoneutral: Serve only as space fillers. Examples are materials such as non resorbable hydroxyapatite and HTR (Hard tissue replacement grafts) Osteogentic: Means that the new bone is formed by bone cells contained in the grafted material itself (autogenous bone grafts). Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Classification of Grafts 1- Autogenous grafts (Autografts): Extra oral. Hip marrow DFDBA is the only non- Intra oral. Extraction sites, tuberosity ….etc autogenous material that 2- Allogenic grafts (Allografts): meets the criteria for an ideal Fresh frozen bone. grafting material which are: Freeze dried bone allografts (FDBA). Availability. Demineralized freeze dried bone allografts (DFDBA).= BMP Predictability. 3.Xenogenic grafts (Xenografts) Biocompatibility. Osteoinductive. Equine, bovine. Osteoconductive. Cost effective. Safety. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Classification of Grafts 3- Bone substitutes Bovine derived hydroxyapatite. Coralline calcium carbonate. 4. Alloplastic grafts (Alloplasts) * Bioceramics. Tricalcium phosphate Hydroxyapatite * Polymers Hard tissue replacement (HRT) polymer. * Bioactive glasses. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Selection of the graft material An ideal graft material should fulfil the following criteria: 1. Osteoinductive potential. 2. Osteoconductive. 3. Accessibility (the material should be obtained easily). 4. Availability (sufficient amount of material should be easy to obtain). 5. Safety: - Biologic compatibility. - Should have no risk of disease transmission (AIDS, viruses). Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU GRAFTS Autogenous Bone Grafting Allogenic Xenograft Alloplastic Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Autogenous bone grafts Autogenous grafts are grafts obtained from the same individual and so have the advantage of not eliciting any immune reaction or having the risk of disease transfer. They are considered osteogenic and osteoinductive grafts. These grafts induce or promote bone growth. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Guided tissue regeneration (GRT): Periodontal therapy has two major goals Elimination of tissue inflammation. Correction of defect caused by disease. Typically, the type of healing that follows conventional surgical therapy is best described as : repair involving a combination of = connective tissue adhesion + attachment or formation of a long junctional epithelium. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Principles of GTR GTR is a term used to define procedures that aim at regeneration of lost periodontal structures (i.e. cementum, periodontal ligament (PDL) and alveolar bone through selective cell and tissue repopulation of periodontal wound. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Barriers offer three advantages during wound healing Exclusion of the epithelium and gingival connective tissue cells from the periodontal defect during healing. This will allow the pleuripotential cells (undifferentiated mesenchymal cells) to repopulate the periodontal defect. Barriers (membranes) maintain space between the defect and the barrier, allowing the entry of regenerative cells from the periodontal ligament. Barrier helps to stabilize the clot. This may help in regeneration. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Indications for GTR: Furcations. Intra bony defects. Gingival recession. Alveolar ridge augmentation Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  should be biocompatible. Should not elicit an immune response. Material should act as a barrier to excluded undesirable cell types to enter the space adjacent to the tooth. Barrier must create a space adjacent to the root surface to allow ingrowth of tissues from the periodontal ligament Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Technique for GTR Surgery is initiated by: Sulcular incisions.. All granulation tissue is removed. Thorough debridement of the root surfaces is performed.. The shape most suitable for covering the defect is selected and additional adjustment is performed according to the defect. The shaping of the barrier is done in such a way that it adapts closely to the tooth and is completely covering the defect extending at least 3 mm on the bone beyond the defect margins after placement.. The barrier materials are fixed to the tooth with sutures using the sling technique. Rinse with chlorhexidine gluconate (0.2%) for at least 4 weeks. ✓ Systemic antibiotics are frequently administered before surgery and during 1-2 weeks after surgery. ✓ Non-resorbable membranes are removed after 4-6 weeks. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Causes of failure Surgical technique: Post surgical factors Improper incision placement (e.g excessive loss of marginal tissue).  Plaque recolonization. Traumatic flap elevation and  Mechanical insult. management. Excessive surgical time.  Loss of wound stability (e.g Inadequate closure or suturing loose sutures loss of early fibrin (failure to achieve primary closure). clot). Barrier dependent factors:  Inadequate root-barrier adapation.  Non sterile technique (plaque or saliva contamination of barrier).  Premature exposure of barrier to oral environment and microbes.  Premature loss or degradation of barrier. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Contra-indications for GTR Class II furcations on the mesial and distal maxillary molars and Premolar furcations. Horizontal bone loss patient’s health, compliance, and tooth mobility. Any medication, condition or disease, such as poorly controlled diabetes mellitus which may interfere with patient’s healing. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Types of barrier membranes Bio-absorbable barrier membranes Non-absorbable barrier membranes Bioabsorbable barriers have been This type of membrane persists after healing introduced in order to avoid a second and must be removed by a second operation. surgery for membrane removal. Advantage of non-resorbable barriers is its Barrier membranes may be: persistance for a suitable period of time to support the process of GTR.  Collagen: Post operative antibiotics is important to The main drawback in collagen suppress subgingival plaque. barriers is the probability of eliciting an immune response. Non-absorbable barriers are removed after 6-8 weeks.  Polylactic acid and polyglycolic acid polymersor mixtures of both. : Complications that are unique to GTR included barrier exposure and infection ✓ Barrier degradation occurs by around the barrier. hydrolysis of ester bonds. This process requires nearly 30-60 days Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Non-absorbable barrier membranes Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Bio-absorbable barrier membranes Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Five major commercial polymers available Guidor Vicryl: It is a periodontal mesh made ✓ Is a hydrophobic barrier material from copolymer of glycolide and made of lactide. Idegrade over a period of 3-12 weeks. = ( polylactic acid (PLA) combined with + citric acid ester.. Atrisorb:  Consists of a polymer of  Barrier is made with absorbable lactic acid, poly (D, L sutures attached and continuous with lactide), dissolved in N- the collar region. methyl-2-pyrolidone (NMP).  The material is designed to resist  Atrisorb is prepared as a and degradation for up to 3 months, solution that coagulates or then gradually resorbs. sets to a firm consistency on contact with water or other Associate. Prof. Marwa.M.tawfiq, Oral aqueous solutions. medicine&Periodontology , BSU  Five major commercial polymers available are: Resolut: It is a copolymer of PGA and PLA that degrades over a period of 4 weeks to 8 months. Its results are similar to e-PTFE due to its prolonged resorption time. Epi-Guide:  It is a hydrophilic membrane formed from PLA. It contains a flexible open cell structure Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Root surface conditioning material Tetracycline Citric acid Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Root surface conditioning Citric acid: is used as an adjunct (helper) in periodontal therapy. It may act by: Removal of endotoxin from root Tetracycline: surface. Exposes the dentin and used for root conditioning may act cementum collagen matrix by: providing anchorage for new fibrin clot and new collagen  Exposing the dentin and fibrils.* cementum collagen (by demineralization).  Removes endotoxin.  Substantivity,collagenase inhibition antibacterial effect Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU Biologic mediators for periodontal regeneration The key to tissue regeneration is to stimulate a series of events which can result in coordination and completion of the tissue formation. Among the various biologic approaches used to promote regeneration are: 1- Growth and differentiation factors: 2- Mediators of bone metabolism Bone morphogenetic proteins (BMP’s). 3- Attachment factors (Fibronectin). 4- Extra cellular matrix proteins (Enamel matrix proteins). Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU 1- Growth factors “Growth factors” is a term used to describe a class of proteins that stimulate a wide variety of cellular events such as proliferation, chemotaxis, differentiation and production of extracellular matrix proteins. Among the growth factors used as adjuncts in periodontal therapy are: Platelet derived growth factor (PDGF). Insulin like growth factor (IGF). Fibroblast growth factor(FGF). Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Insulin growth factor Insulin Growth factor I and insulin growth factor II are peptide growth factors with biochemical and functional similarities to insulin. They stimulate proliferation of fibroblasts, bone cells and also the formation of type I collagen synthesis. Therefore, the insulin growth factors increase both the number of cells synthesizing bone as well as the amount of extracellular matrix deposited by each cell Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  2- Mediators of bone formation Bone morphogenetic proteins (BMP’s)  BMP’s constitute a large family of regulatory factors.  They have been found in bone-inductive extracts of bone.  These BMP’s function by making mesenchymal precursor cells differentiate into mature osteoblasts and/or chondroblasts.  BMPs also are chemotactic for some cell types of the osteoblastic line.  BMPs are able to induce bone formation and so are good candidates for regeneration of alveolar bone Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  3- attachment factors; Fibronectin Fibronectin is a large glycoprotein present in serum and produced by many cells. Fibronectin is the glycoprotein that fibroblasts require to attach to root surface i.e. it aids attachment of cells to extracellular matrix and so has an important role in tissue regeneration and wound healing. The addition of fibronectin to the root surface may : ✓promote new attachment. ✓ clot attachment and so may delay apical migration of epithelial cells. ✓ stimulate periodontal ligament cells especially fibroblasts to repopulate the root surface. In periodontal therapy, application of fibronectin has been combined with surface demineralization of the root. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  4- Extracellular matrix proteins (enamel matrix proteins) The enamel matrix derivative (EMD) for periodontal regeneration has been suggested because it resembles the way these materials behave in normal tooth development. These enamel matrix proteins appear to be involved in formation of cementum. They have been found to stimulate regeneration of firmly attached acellular cementum. Combination of any of the previous regenerative techniques may be performed. Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU REFERNCES : Prof. Mona Shoeib Professor of Oral diagnosis , Oral medicine and periodontology , faculty of dentistry Cairo university AL KASR EL AIEANY students book 2016 Prof. Usama Gouda (Professor of Oral diagnosis , Oral medicine and periodontology , faculty of dentistry , Badr University Newman and Carranza's Clinical Periodontology. 2021 Associate. Prof. Marwa.M.tawfiq, Oral medicine&Periodontology , BSU  Bone Regeneration in Implant Dentistry ❑ Dental implants have become a widely accepted and successful treatment option for restoring missing teeth. ❑ The alveolar bone has been compromised, often due to previous tooth loss, periodontal disease, or trauma. ❑ Bone regeneration procedures are essential to create an adequate foundation for the placement and long- term success of dental implants. ❑ The key factors that can impact the clinical outcomes of bone regeneration in implant dentistry, from the underlying biology to patient-related considerations. by Dr.marwa Tawfiq Bone regeneration in implant dentistry: Which are the factors affecting the clinical outcome?  Bone regeneration procedures have been performed together with implant placement with the aim to: re- establish an adequate alveolar ridge dimension before implant placement with the aim to regenerate peri- implant bone simultaneous to implant placement and allow a prosthetically driven implant- supported rehabilitation hard tissue augmentation techniques has been documented for :alveolar ridge regeneration/augmentation, including : guided bone regeneration , onlay grafting, combinations of onlay and interpositional grafting, distraction osteogenesis, ridge splitting, and free vascularized autografts. highly predictable, continuous efforts are directed to the long- term success of implant rehabilitations and to lower the risk of complications during healing. regenerative procedures have been applied, depend on the type of implant surface/design and biomaterials employed, different surgery- related , prosthesis- related and patient- related factors can impact on the expected outcomes Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU The Biology of Bone Regeneration 1 Cell Recruitment Successful bone regeneration requires the recruitment of osteoprogenitor cells, such as mesenchymal stem cells, as well as inflammatory cells, to the site of the defect. These cells are essential for the initiation of the regenerative process. 2 Matrix Deposition The deposition of a provisional extracellular matrix, known as the blood clot, provides a scaffold for the migration and proliferation of the recruited cells. This matrix serves as a platform for the subsequent deposition of the bone matrix. 3 Signaling Pathways Complex signaling pathways, such as the BMP, and VEGF pathways, regulate the differentiation of osteoprogenitor cells into mature osteoblasts, as well as the processes of angiogenesis and bone remodeling.  ▪ Bone regeneration it is important to have a source of cells , a scaffold that facilitates the deposition of the bone matrix, signaling molecules, as well as an adequate blood supply and THE BIOLOGY OF BONE mechanical stability to allow the maturation of the immature woven REGENERATION bone into mature lamellar bone ▪ The biological events and signaling pathways involved in bone Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department regeneration applying the GBR ,BSU  | THE IMPACT OF SURGERY- RELATED FACTORS Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  The Impact of Surgery-Related Factors Submerged vs. Non-Submerged Surgical Complications Wound Healing Management Healing The choice between submerged and non- Complications such as: Proper wound management, submerged healing protocols for: soft tissue dehiscence, including techniques for primary Implants placed with simultaneous bone membrane exposure, wound closure and the stabilization of regeneration can impact the stability and infection can negatively impact membranes and grafts, plays a predictability of the regenerative bone regeneration, significant role in the prevention of outcomes. leading to decreased bone complications and the promotion of Minimal differences in short and formation and reduced stability of predictable bone regeneration. moderate term the risk of soft tissue the regenerated tissue. complications and membrane exposure Understanding and minimizing the may be higher with non-submerged risk of these complications is approaches. crucial for successful outcomes.  SUBMERGED VERSUS NON- SUBMERGED HEALING A submerged healing protocol important To minimize the risk of fibrous integration and microbiological contamination due to implant micromovements during osseointegration, the development of one- piece implants and non- submerged implant protocols have suggested the possibility of eliminating the second stage surgery, with the aim of preventing also the coronal migration of the mucogingival junction that might be seen in submerged implants. A minimal differences in short- and moderate- term healing outcomes, as well as crestal bone level changes between submerged versus non-submerged implants placed without GBR Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  SUBMERGED VERSUS NON- SUBMERGED HEALING Different considerations should be made when bone regeneration concomitant to implant placement is required Non- submerged healing may increase the risk of contamination of the inserted biomaterial due to the inability to attain complete primary closure following surgical implant placement Submerged compared to non- submerged healing showed that implant osseointegration and bone regeneration occurred in both instances. Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  | SURGICAL COMPLICATIONS Despite bone regeneration procedures performed simultaneously to implant placement are predictable and well- documented, they are also relatively technique- sensitive As such, post- surgical complications, which mainly include soft tissue dehiscence, exposure of membranes/biomaterials, and infection Minimizing the impact of such complications becomes of crucial importance to ensure predictable regenerative outcomes on augmentation indicated that the most frequently reported complications on GBR were per- implant mucosal problems, including redness, hyperplasia, suppuration, pain, and swelling. GBR- based lprocedures performed concomitant or before implant placement and indicated that overall the weighted rate of soft tissue complications was , with no differences between resorbable and non- resorbable membranes. Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU The Impact of Implant Surface Characteristics 1 Osseointegration 2 Bone Formation Implant surface properties, such as: Hydrophilic, moderately rough topography, surfaces have been shown to wettability, enhance early bone formation and chemistry, can directly and promote a more favorable influence the process of immune response, leading to osseointegration and the improved outcomes in bone subsequent bone regeneration regeneration procedures. around the implant. 3 Molecular Mechanisms The influence of implant surface characteristics on bone regeneration is mediated through complex signaling pathways, which regulate key processes like cell proliferation, osteogenesis, and angiogenesis.  | THE IMPACT OF IMPLANT SURFACE ▪ the development of titanium implants with modified surface properties , essentially with the aim to improve osseointegration and shorten healing times. ▪ the surface properties and chemistry of implants directly influence the binding capacity of fibrin and the adhesion, proliferation, and differentiation of cells, thus affecting the overall process of osseointegration. ▪ In particular, moderately rough, hydrophilic surfaces have shown faster osseointegration in comparison to hydrophobic surfaces. ▪ although after 4 weeks of healing the outcomes are comparable between the two surfaces Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  | THE IMPACT OF IMPLANT SURFACE ▪ Titanium surface topography and chemistry have also shown to influence the proteomic profile released by platelets, which can subsequently influence macrophage pro-inflammatory cytokine expression ▪ Hydro- philic surfaces are able to: Elicit a macrophage phenotype associated with reduced inflammation and enhanced pro- osteogenic signaling. ▪ Different types of modified titanium surfaces have been tested for their ability to promote new bone formation in bone defects created around implants ▪ Hydroxyapatite- coated implants promoted better bone- to- implant contact in the regenerated bone as compared to pure titanium. Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  The Impact of Barrier Membranes and Bone Grafts Barrier Membranes Bone Grafts ❑ Barrier membranes play a crucial role in The selection of an appropriate bone graft guided bone regeneration, or substitute material is essential for : ❑ creating a secluded space for bone o space maintenance, osteoconduction, and formation and preventing the migration the overall success of bone regeneration. of unwanted cells. o Factors like graft microstructure, ❑ Factors such as porosity, occlusiveness, macrostructure, and resorption rate can and resorption pattern can influence the impact the regenerative process. regenerative outcomes. Synergistic Effects Wound Healing Management The combination of barrier membranes and bone grafts/substitutes can have a Proper stabilization and fixation of the synergistic effect on bone regeneration, membrane and graft materials are crucial to with the membrane providing space prevent complications and ensure the maintenance and the graft material serving as a predictability of bone regeneration outcomes. scaffold for bone formation.  ▪ Barrier membranes and bone | THE IMPACT OF grafts/substitutes are still the preferred regenerative materials for BIOMATERIALS bone regeneration in implant dentistry. Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU The Impact of Barrier Membranes and Bone Grafts  | BARRIER MEMBRANES The principle of guided bone regeneration is based on:the use of an occlusive barrier membrane with the aim to create a secluded space around a bone defect and facilitate the recruitment and proliferation of osteoprogenitor cells from the marrow spaces directly into the defect while preventing the downgrowth of the neighboring soft tissues. The composition as well as the physical and mechanical properties of barriers can obviously influence the regenerative outcomes of peri- implant bone defects Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU THE MAIN ADVANTAGES AND DISADVANTAGES ASSOCIATED WITH THE DIFFERENT TYPES OF BARRIERS AND BONE GRAFTS AVAILABLE. Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  1.OCCLUSIVENESS/POROSITY An ideal level of occlusiveness and porosity enabling the membrane to act as: ✓ an effective barrier but at the same time allowing the passage of nutrients, fluids, oxygen, and bioactive substances for cell growth ▪ Commercially available membranes present: ✓ a wide variability in the pore size and degree of permeability, ranging from micro- porosity ✓ which may limit the passage of cells but allows the passage of chemicals, biomolecules and viruses; ▪ Moderate porosity that allows the passage of: bacteria, cells and tissue integration/migration; or macro- porosity , ✓ which allows the unrestricted passage of chemicals, biomolecules, viruses, bacteria, cells and promotes tissue integration and migration. Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  OCCLUSIVENESS/POROSITY ▪ At 6 weeks of healing showed that: The amount of soft tissue invasion was proportional to the increasing perforation size and that a membrane porosity in the range of 25– 100 μm promoted enhanced bone formation in the early phases of bone healing, ▪ While the material with the smallest internodal distance did not integrate well with the surrounding tissues ▪ In healthy conditions an occlusive membrane compared to a perforated membrane enhanced the regeneration of critical size defects, In uncontrolled diabetic conditions a perforated barrier improved the outcomes as Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU compared to an occlusive membrane.  2-STABILIZATION ▪ Stabilization of the blood clot is a prerequisite for bone regeneration to take place ▪ It is known that micromovements between bone and any implanted material prevent bone formation, resulting in the development of fibrous tissue. ▪ As such, the stability and immobilization of the membrane becomes of crucial importance, while maintaining the defect space Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  2 | STABILIZATION ▪ In order to maximize membrane stability when performing GBR simultaneous to implant placement a variety of stabilization methods have been suggested, including fixation screws, non- resorbable pins or titanium pins, ▪ It is indicated that the membranes were tucked under the flaps. Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  2 | STABILIZATION Non-resorbable membrane ▪ It is indicated similar vertical dehiscence and defect width reduction ✓with an e- PTFE membrane alone ✓ Or combined with allograft particles mixed with tetracycline were employed, ✓thus stressing the importance of space provision for a successful GBR. ▪ Comparing a resorbable collagen membrane to an e- PTFE membrane associated with DBBM for the regeneration of peri- implant dehiscence defects concomitant to implant placement clearly indicated that membrane stabilization rather than the type of biomaterials used played a major role in the number of post- operative complications. Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU Resorbable membranes 2 | STABILIZATION ▪ The stabilization of poly-lactic acid (PLLA) membranes with fixation pins increased the amount of bone regeneration in alveolar ridge defects as compared to PLLA membranes alone. ▪ two different types of collagen membranes applied together with Deproteinized bovine bone mineral (DBBM) particulate graft DBBM, which were either unfixed or fixed with six mini screws. ✓ membrane fixation made no difference to the overall volume stability of the grafted sites, ✓ the type of collagen membrane affected the GBR outcomes, particularly in cases where the membrane was not fixed ▪ A possible drawback when using certain fixation system is: the risk of perforating important anatomical structures (like adjacent teeth, nerves, and sinus membrane), which could be avoided by the use of periosteal sutures Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU 2 | STABILIZATION Securing the stability of barrier membranes and the underlying grafting materials/blood clot plays a crucial role in the success of GBR procedures. ✓ There is no guideline on how to reach such an outcome (whether with pins, screws or sutures, or simply adapting the membrane under the flap), clinical experience suggests that the clinician should make a decision based on the defect anatomy, location, and biomechanical properties of the biomaterials used.  3 | RESORPTION PATTERN ▪ An ideal membrane should gradually resorb over time ▪ While collagen membranes present excellent: while bone forms and matures and its degradation products should not jeopardize the regeneration process. ✓ biocompatibility, ▪ Despite superior mechanical properties and good ✓ chemotactic properties, and their degradation does not exert any potential deleterious effect on compatibility, it is clear that non- resorbable membranes the bone tissue, present the important drawback : ✓ their lack of rigidity and limited space making ✓ of always requiring a second- stage surgery in order to capability often require their combination with a be removed, space- making bone graft. ✓ which extends the overall treatment time, ▪ the degradation pattern of a collagen membrane associated with a particulate graft in a ✓ increases patient morbidity and poses risks for biological preclinical model and showed that at 30 days the complications membranes were significantly ▪ As such, resorbable barriers were introduced as second- ▪ reduced in thickness and they presented a generation devices, which mainly include collagen- diffuse infiltration by vessels and immature woven bone. derived and polymeric barriers Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  3 | RESORPTION PATTERN The resorption rate of a grafting material depends on its physical and chemical properties. Autologous bone grafts are incorporated into the surrounding bone through a process called “creeping substitution”. in case of cortical bone, the regeneration process is mainly preceded by resorption, while in cancellous bone the osseous formation is initiated directly in the marrow spaces, by the differentiation of graft mesenchymal cells into osteoblasts. Besides the use of a barrier, in order to slow down resorption and enhance volume maintenance of autologous grafts, different strategies have been proposed, including the combination with a slow-resorption particulate graft or the combination with bioactive factors. Allograft incorporation follows a similar sequence of events but vascular penetration, bone formation, and remodeling are slower and reduced as compared to autografts Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  4 | BIOACTIVITY ▪ In fact membranes do not simply work as barriers to prevent the migration of undesired cells, but they also behave as bioactive compartments that directly promote the biological events underpinning bone formation. ▪ both resorbable and non- resorbable membranes are able to promote and direct the regenerative process by virtue of hosting cells that express and secrete pro-osteogenic and bone- promoting factors. Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  4 | BIOACTIVITY The developing immune- mediated collagen membranes that can potentially regulate the behavior of macrophages, including: the recruitment, polarization, and the cytokines secreted by different phenotypes during every stage of the healing process. by modifying surface properties, ✓ particle size, ✓ porosity, ✓ and the released ions = an ideal immune- mediated collagen membrane promote anti- inflammatory M2- type macrophages and the secretion of pro- regenerative cytokines + with the ability of preventing migration of the epithelium and Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department maintaining space for bone ingrowth. ,BSU  5 | ONE- LAYER VERSUS TWO- LAYER MEMBRANES ▪ The use of a double- layer membrane has been proposed with the aim to further enhance : ✓ the membrane barrier effect and possibly increase the stability of the underlying graft, particularly in case of resorbable collagen membranes ✓ the double layer technique has shown to delay the resorption time, thus prolonging the barrier effect of the material ▪ While one layer of collagen membrane is often sufficient to: ✓ promote bone regeneration. ▪ The clinical advantage of using double- layer membranes for staged ridge augmentation in patients undergoing implant rehabilitations ▪ they covered sites horizontally grafted by bone blocks with a DBBM particulate graft and then applied a double- layer collagen membrane. ▪ This technique allowed a better protection of the graft and increased the stability of the membrane, leading to a reduction of only 7% of the total width of the graft after 6 months Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  | BONE GRAFTS ▪ The main purposes for the application of bone grafts or substitutes included enhancement of bone healing by: ✓ Bridging small to large defects, ✓Prevention of membrane collapse by maintaining the space beneath the membrane, ✓ Stabilization of the blood clot and prevention/reduction of bone resorption ▪ Bone augmentation materials are commonly classified according to their origin Into autologous grafts , allogenic grafts , xenogenic grafts , or alloplastic grafts Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  | BONE GRAFTS ▪ The properties of an ideal bone replacement graft have been defined as part of the recent Consensus Report of the 15th European Workshop on Periodontology on Bone Regeneration and they include: ▪ biocompatibility, porosity, osteoinductivity, osteoconductivity, surface properties adequate for protein adsorption, extracellular matrix deposition, cell adhesion, differentiation and migration, biodegradability, mechanical properties mimicking bone properties, angiogenicity, easiness of handling and manufacturing processes. ▪ Allografts are a valid alternative to autologous grafts and are available in different forms: fresh, fresh frozen, freeze- dried, and demineralized freeze- ,BSU dried Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department  | MICRO AND MACRO ARCHITECTURE ▪ The microarchitecture of a grafting material, including its relative cortical and cancellous composition, together with its embryogenic origin influences its resorption rate and degree of angiogenesis, which can affect volume maintenance over time. ▪ The superiority of intramembranous versus endochondral autogenous bone grafts when combined or not with a membrane that bone graft's survival is determined primarily by its relative cortical and cancellous composition rather than its embryologic origin. ▪ Proximity of the elastic modules of bone grafts to the human structure is another important factor when dealing with bone regeneration procedures. ▪ the graft structure should have an ideal: ▪ pore size that enables turnover of the required nutrients, ▪ signaling factors, ▪ proteins, ▪ chemicals, and end- products within the wound. Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  2.| MICRO AND MACRO ARCHITECTURE ▪ different bone graft materials suggested a greater degree and faster rate of bone penetration as the macroporosity of a scaffold increases. ▪ In contrast, increased levels of microporosity/strut porosity also appear to promote osteogenesis and a faster apposition of a greater volume of new bone. ▪ Similarly, the degree of structural interconnectivity between the pores of the graft material was shown to influence the speed and extent of the development of the vascular network essential for new bone Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department formation. ,BSU  | SPACE MAINTENANCE ▪ Together with primary wound closure, angiogenesis, and clot stability, space maintenance is one of the key factors for successful new bone formation following GBR procedures. ▪ A favorable correlation has been observed between space protection and the level of new bone formation. ▪ Both resorbable and to a lesser extent non- resorbable membranes have limitations for maintaining the architecture of the defect due to their limited rigidity ▪ The space- maintenance capability of a bone filler would ensure an ideal microenvironment for the revascularization of the augmented volume and enable tissue to form in a preserved and protected space ▪ Although bone grafts play a crucial role in space maintenance, when a biomaterial is present , it can also delay the osseous formation process by occupying the space where the newly formed tissue should form Ass.Prof.Marwa.M.Tawfiq ,BSU Associate professor of oral medicine &Periodontology department Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU 6 | THE IMPACT OF PROSTHETIC FACTORS Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  The Impact of Prosthetic Factors Implant Loading Abutment Characteristics The timing of implant loading, whether The design and properties of the implant- immediate, early, or conventional, can abutment interface may play a role in the stability influence the stability and integration of the of the peri-implant soft tissues and the regenerated bone, though the impact appears maintenance of the regenerated bone, though to be limited when proper protocols are more research is needed in this area. followed. ▪ Immediate loading, when an implant- retained prosthesis is connected within 1 week following implant placement ▪ Early loading, when an implant- retained prosthesis is connected between 1 week and 2 months following implant placement ▪ Conventional loading, when implants are allowed to heal for more than 2 months after placement, without connecting a prosthesis  | ABUTMENT CHARACTERISTICS Guided bone regeneration is often performed to allow the correct prosthetic positioning of implants, which ultimately influences their long- term clinical success Morphologically, the implant supra- crestal complex extends from the coronal aspect of the peri- implant mucosa to the marginal peri- implant bone level, thus encompassing the implant- abutment- prosthesis junction. The labial osseous defects were classified as U- , V,- or UU- shaped, and were simultaneously grafted using autologous and xenogenic bone Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU The Impact of Patient-Related Factors Periodontitis History Patients with a history of periodontitis may require stricter plaque control and supportive care to ensure the long-term stability of bone regeneration around dental implants. Systemic Conditions Underlying medical conditions, such as diabetes and osteoporosis, can negatively impact the bone regeneration process and increase the risk of complications, necessitating careful case selection and management. Smoking Smoking has a detrimental effect on wound healing and bone regeneration, leading to an increased risk of complications and implant failure, and should be considered a significant risk factor. preencoded.png 1 | HISTORY OF PERIODONTITIS, COMPLIANCE AND ORAL HYGIENE Assessment of oral situation, including peri- implant tissue health, prosthetic Interview Reinforce risk factor control components and patient competence to undertake oral hygiene Professional intervention: individualized oral Determination of next recall healthcare plan, including interval tailored according to oral hygiene coaching and patient- , implant- , and professional mechanical restoration- based risk plaque removal of the entire factors dentition/implants Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  2 | SYSTEMIC CONDITIONS AND SMOKING Besides underlying medical The increasing demand for conditions that can place the implant- based treatments patients at risk during surgery together with the demographic irrespectively of:the nature of the shift toward an ageing intervention, different diseases that have a direct/indirect impact population have resulted in a on bone and soft tissue healing growing the impact of systemic may potentially affect the conditions on the success/ outcomes of bone regenerative\a survival of implant procedures performed as part of rehabilitations. implant rehabilitations Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  | DIABETES MELLITUS While the majority of the studies have focused on the impact of systemic conditions on: osseointegration and implant loss, the underlying medical conditions may have when regenerative procedures are performed together with implant placement. Diabetes mellitus has been associated with the occurrence of a series of complications on the skeletal system collectively referred to as “diabetic bone disease” or “diabetic osteopathy ▪ Impaired peri- implant bone formation and mineralization, as well as impaired regeneration of peri- implant dehiscence defects ▪ With the shed light on the molecular mechanisms behind the negative impact of hyperglycemia on bone regeneration. Remarkably, we showed that uncontrolled diabetes is associated with a delayed and prolonged inflammatory response and with a downregulation of key genes and Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU pathways implicated in the osteogenesis process.  2 | OSTEOPOROSIS ▪ Osteoporosis has a detrimental effect on the jawbones, growing evidence from pre- clinical and clinical studies seems to suggest a correlation between bone density measured at different systemic skeletal sites and at the jawbones, and that osteoporosis is associated with a reduced bone quality and increased cortical porosity in the jaws. ▪ The clinicians may consider a longer healing period for implant osseointegration before prostheses insertion in patients with osteoporosis ▪ Despite pre-clinical studies overall suggest a lower Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department osseointegration rate and reduced mechanical properties ,BSU in osteoporotic bone clinical evidence is far less robust.  2 | OSTEOPOROSIS ▪ Therefore, nowadays a diagnosis of osteopenia or osteoporosis is not considered an absolute contraindication to dental implants. ▪ Some studies also showed successful buccal bone regeneration Nevertheless, there are data coming mainly from retrospective studies speculating that osteoporosis may negatively impact on large bone reconstructions, ▪ such as in pre-prosthetic graft surgeries or sinus augmentation. ▪ Pre- clinical studies also suggested that osteoporosis might negatively impact on bone regeneration Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  The Risk of Peri-Implantitis Prevalence of Peri-Implant Mucositis Prevalence of Peri-Implantitis 22.4% in pristine sites Low in augmented sites (long-term) 19.6% in augmented sites Higher risk with residual defect height >1mm THE RISK OF PERI-IMPLANTITIS ▪ While the incidence of peri-implantitis in regenerated sites is not significantly different from pristine sites, some studies suggest a higher risk of larger peri-implantitis lesions in augmented areas, particularly when using implants with modified surfaces. ▪ Regular supportive care and close monitoring are essential to prevent and manage peri-implant diseases in both pristine and regenerated sites.  Future Directions in Bone Regeneration Tissue Engineering Approaches Immunomodulation As the field of bone tissue engineering Understanding the complex progresses, the integration of interplay between the immune osteogenic cells, bioactive signals, and system and bone regeneration smart biomaterials with tailored may lead to the development of properties may revolutionize the way biomaterials and strategies that we approach bone regeneration in can actively regulate the implant dentistry, overcoming the inflammatory response and limitations of traditional barrier promote a pro-regenerative membranes and bone grafts. environment. Personalized Approaches The use of advanced technologies, such as proteomics and transcriptomics, can provide valuable insights into the patient-specific biological mechanisms underlying bone regeneration, enabling the development of personalized treatment protocols for optimal outcomes.  Remember Bone regeneration is a crucial component of successful dental implant therapy, as it allows for the restoration of adequate alveolar bone volume and quality. While significant progress has been made in understanding the key biological and clinical factors that influence the outcomes of bone regeneration, further research and collaboration between scientists, engineers, and clinicians are needed to optimize and personalize these procedures, particularly in challenging patient scenarios. The success and predictability of bone regeneration procedures associated with dental implants are related to the presence of osteoprogenitor cells, creation/maintenance of space with/without a scaffold, adequate blood supply, mechanical stability, and signaling molecules that guide the maturation of the deposited bone matrix Ultimately the goal will be to optimize case selection and at the same time to tailor the regenerative procedure based on the different specific local and systemic factors Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  REFERNCES : Donos N, Akcali A, Padhye N,Sculean A, Calciolari E. Bone regeneration in implant dentistry:Which are the factors affecting the clinical outcome?Periodontol 2000. 2023;93:26-55. Prof. Mona Shoeib Professor of Oral diagnosis , Oral medicine and periodontology , faculty of dentistry Cairo university AL KASR EL AIEANY students book 2016 Prof. Usama Gouda (Professor of Oral diagnosis , Oral medicine and periodontology , faculty of dentistry , Badr University Newman and Carranza's Clinical Periodontology. 2023 Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU  Thank you Ass.Prof.Marwa.M.Tawfiq Associate professor of oral medicine &Periodontology department ,BSU