Principle Of Guided Tissue Regeneration Research Articles

Is selective protein adsorption on biomaterials a viable option to promote periodontal regeneration?

Periodontitis is an inflammatory condition that can induce significant destruction of the periodontium, the set of specialized tissues that provide nourishment and support to the teeth. According to the guided tissue regeneration principles, the periodontium can be regenerated if the spatiotemporal control of wound healing is obtained, namely the tune control of cell response.After material implantation, protein adsorption at the interface is the first occurring biological event, which influences subsequent cell response. With the regard of this, we hypothesize that the control of selective adsorption of biological cues from the surrounding milieu may be a key-point to control selective cell colonization of scaffolds for periodontal tissue regeneration.

How do GTR and GBR Differ? A Periodontitis Case Treated Using an Equine-derived, Enzyme-deantigenic, Collagenpreserving Bone Graft, and Collagen Membranes

The present case illustrates how a tooth, which had a highly questionable prognosis, was preserved by carrying out a periodontal regeneration surgery. Treatment of periodontitis involves a careful consideration of all the factors that may allow the achievement of a favorable outcome; among those, the skillful use of guided tissue regeneration (GTR) membranes is of paramount importance. A 39-year-old patient presented with a mobile central upper incisor due to severe periodontitis and was treated according to GTR principles using a collagen membrane. A collagen-preserving bone graft was also used, as a scaffold for clot formation and cellular infiltration, which was covered with a second collagen membrane. The patient was contacted for follow-up assessment at 3, 6, 12, and 18 months after surgery. Follow-up radiographs showed that bone regeneration occurred around the involved tooth and very little tooth mobility was observed. The patient's masticatory function, appearance, and comfort were favorable. The use of two equine collagen membranes with the purpose of creating the best conditions to carry out periodontal regeneration according to GTR principles, in association with an equine, collagen-preserving, enzyme-deantigenic bone graft, allowed sufficient bone regeneration to salvage a tooth that was deemed otherwise lost because of periodontitis. In cases of teeth that are severely compromised by periodontitis, the use of collagen membranes according to GTR principles can allow the regeneration of the periodontal tissues; the association with a bone substitute having well-known performance rates, covered with a collagen membrane (guided bone regeneration, GBR) can, in some cases, improve bone regeneration at the defect site.

Guided Tissue Regeneration to Treat Mucogingival Defects Using a Collagen Sponge as a Space‐Filler Material for Cell Proliferation: Clinical Case Reports With Long‐Term Follow‐Up

Introduction: Guided tissue regeneration (GTR) protocols for root coverage have proposed space‐filler artifacts to create an area between the membrane and the root surface to provide adequate space for cell migration. Extensive instrumentation of the root to obtain a concave shape, suturing of the membrane to keep it convex, or the use of titanium‐reinforced membranes are some of the most common techniques for creating the space needed for regeneration. The primary objective of these case reports is to show the clinical application of collagen sponge as a space‐filler material in cases in which GTR procedures were used to treat marginal tissue recession.Case Presentation: These case reports describe the results obtained with root‐coverage procedures of a Miller Class I defect on the buccal surface of tooth #11 in two patients. Bioabsorbable polyglactin 910 and non‐absorbable expanded polytetrafluoroethylene barrier membranes were used along with a collagen sponge interposed on the root surface. It should be emphasized that the use of the collagen sponge was to create a biologic space and thereby induce cellular proliferation at the site of the recession. Three years after surgery, the treated areas showed complete root coverage with an increase of keratinized and attached gingiva with appropriate contour and thickness.Conclusion: These results demonstrate the possibility of using a collagen sponge as a space‐filler material in cases in which the principles of GTR are used in the successful treatment of root recession.

Calcium sulfate in periodontics: A time tested versatile alloplast

Calcium sulfate has multifaceted properties and has versatile use in the field of periodontal practice. Calcium sulfate can function as a resorbable space filler, a resorbable barrier (compatible with guided tissue regeneration principles), as a combination with other bone grafts in intrabony defects and in socket preservation procedures for implant placement. This review is an attempt to shed light on various applications of this bone graft in periodontal regeneration.

Treatment of intrabony defects with guided tissue regeneration in aggressive periodontitis: clinical outcomes at 6 and 12months.

The aim of this study was to compare clinical outcomes between guided tissue regeneration (GTR) and access flap (AF) surgery in patients with aggressive periodontitis (AgP). Eighteen AgP patients with similar bilateral intrabony defects were treated in this split-mouth, single-blinded, randomised, controlled clinical trial. All patients presented with ≥3mm intrabony defects and ≥5mm periodontal pocket depths (PPD). In each patient, one defect was treated with a polyglycolide membrane according to the GTR principle, whereas the contralateral side was treated with AF. For both sides, a simplified papilla preservation flap was used. At baseline, 6 and 12months post-surgery, the clinical attachment levels (CAL) and PPD were evaluated. At 6 and 12months, at the GTR sites, the mean [95% CI] CAL gain was 1.7mm [1.1, 2.3] and 1.6mm [0.9, 2.1], respectively, while the mean [95% CI] PPD reduction was 2.3mm [1.9, 2.8] and 2.4mm [1.9, 2.8], respectively. Similar CAL (1.6mm [1.0, 2.2] and 2.1mm [1.4, 2.7]) and PPD (2.0mm [1.5, 2.4] and 2.5mm [2.0, 3.0]) outcomes were observed at the control sites at 6 and 12months, respectively. Notably, at the GTR-treated sites, 13 subjects presented with various degrees of membrane exposure. Both therapies were effective in the treatment of intrabony defects in AgP patients, and no statistically significant differences between them could be demonstrated, possibly as a result of the differing degrees of membrane exposure at the GTR sites. Both periodontal regeneration and conventional periodontal surgery are effective treatments for AgP patients.

Treatment of a large periradicular defect using guided tissue regeneration: A case report of 2 years follow-up and surgical re-entry

Periradicular (PR) bone defects are common sequelae of chronic endodontic lesions. Sometimes, conventional root canal therapy is not adequate for complete resolution of the lesion. PR surgeries may be warranted in such selected cases. PR surgery provides a ready access for the removal of pathologic tissue from the periapical region, assisting in healing. Recently, the regeneration of the destroyed PR tissues has gained more attention rather than repair. In order to promote regeneration after apical surgery, the principle of guided tissue regeneration (GTR) has proved to be useful. This case presents the management of a large PR lesion in a 42-year-old male subject. The PR lesion associated with 21, 11 and 12 was treated using GTR membrane, fixated with titanium minipins. The case was followed up for 2 years radiographically, and a surgical re-entry confirmed the re-establishment of the lost labial plate. Thus, the principle of GTR may immensely improve the clinical outcome and prognosis of an endodontically involved tooth with a large PR defect.

Collagen-Chitosan barrier membrane, a novel, indigenous, and economic material for management of periodontal infrabony defects - A case-Control Study

Objectives: The main objective of periodontal treatment is to resolve the inflammatory lesion in periodontal tissues. However, the contemporary goal has become regeneration of the lost attachment apparatus through guided tissue regeneration (GTR) technique. The GTR membranes currently available in the market are expensive, which in turn warrants the identification, development, and utilization of more cost-effective and biocompatible materials as barrier membranes for GTR. Materials and Methods: The present case-control study was conducted on patients with infrabony defects having minimal or no gingival recession and with a probing depth of >4 mm and controls (12 each). It highlights the use of a newly developed fish collagen-chitosan film as a barrier membrane for the management of human infrabony defects using the principles of GTR in periodontitis subjects. Results: Infrabony defects in the test and control sites were matched at baseline. The differences in probing pocket depth within the groups at baseline and 6 months after periodontal therapy were statistically significant. After 6 months, there was statistically significant difference in the probing pocket depth between the test and control sites. Conclusion : Within its limitations, the present study showed that the collagen-chitosan film is effective as a barrier membrane for GTR therapy in infrabony defects, as it resulted in improved clinical outcome with low incidence of gingival recession and device exposure.

Guided Tissue Regeneration Principle with Inserts of PerioGlas in Endodontic Surgery: Two Case Reports

ABSTRACT Most periapical radiolucent lesions associated with infections of the root canal system heal uneventfully after endodontic treatment. However, some cases may require periradicular surgery in order to remove pathologic tissue from the periapical region and simultaneously eliminate any source of infection that could not be removed by orthograde root canal treatment. With an adequate technique, surgery can address these issues, although it may be insufficient in some situations. This report describes the healing process after surgery in two cases with a 12 months follow-up. In these cases, apicoectomy was followed by retrograde sealing with Super EBA (Harry J. Bosworth Company, Illinois, USA). The bone defect was filled with PerioGlas (NovaBone, Austin, TX, USA) and covered with a resorbable Guidor membrane (Sunstar, Foster Ave, Chicago, USA). No intraoperative or postoperative complications were observed. After 24 months of follow-up, the patient showed no clinical signs or symptoms associated with the lesion and radiographic examination showed progressive resolution of radiolucency. How to cite this article Lokade J, Wankhade S, Chandak M, Lanjewar A. Guided Tissue Regeneration Principle with Inserts of PerioGlas in Endodontic Surgery: Two Case Reports. Int J Prosthodont Restor Dent 2013;3(2):72-77.

Guided tissue regeneration in communicating periodontal and endodontic lesions - A hope for the hopeless!

The use of guided tissue regeneration (GTR) has become a standard of care in Periodontology. GTR using membrane barriers and/or bone grafting materials has also been used in periapical surgery. However, the application of the GTR principle, particularly in communicating endodontic-periodontal lesions with loss of the buccal cortical plate, is a very challenging task, with very few reported human clinical studies. An interdisciplinary approach, combining endodontic and periodontal (surgical) procedures can save a tooth in the long run that has been defined as hopeless at the preliminary stage of treatment.

The Use of Guided Tissue Regeneration Principles in Endodontic Surgery for Induced Chronic Periodontic‐Endodontic Lesions: A Clinical, Radiographic, and Histologic Evaluation

Chronic periodontic-endodontic lesions are not uncommon in clinical practice and their regenerative capacity has long been questioned. However, there are no published studies investigating the application of guided tissue regeneration techniques in combination with endodontic surgery using an induced perio-endo defect model. This study evaluated the clinical, radiographic, and histologic outcomes of three surgical procedures used to treat induced perio-endo lesions. Pulpal necrosis was induced in foxhounds along with surgical removal of radicular buccal bone. After 4 weeks, chronic lesions were clinically and radiographically assessed. Treatment surgery consisted of apicoectomy, root canal instrumentation, and retrofilling with mineral trioxide aggregate. Teeth were then assigned to one of the following treatment groups: open flap debridement only (OFD), OFD with bioabsorbable porcine-derived collagen membrane (BG), or OFD with BG and anorganic bovine bone matrix (BO/BG). Clinical parameters and standardized radiographs were assessed at defect creation; treatment surgery; and at 1, 2, 4, and 6 months. Animals were sacrificed at 6 months and specimens prepared for histometric analysis. Clinical and radiographic conditions improved during the study period. Mean epithelial attachment was similar between all groups. Mean connective tissue attachment for groups OFD, BG, and BO/BG was 3.79 mm, 2.63 mm, and 1.75 mm, respectively, and mean radicular bone height was 2.16 mm, 3.24 mm, and 3.45 mm, respectively. Statistically significant increases in the amount of new cementum were observed in groups BG and BO/BG when compared with OFD (P <0.05). Treatment of combined induced perio-endo lesions using bioabsorbable collagen membranes alone or in combination with anorganic bovine bone matrix resulted in increased amounts of bone, periodontal ligament, and significant increases in the amount of new cementum when compared to open flap debridement in a canine model.

Guided tissue regeneration enhances osteogenesis in a rat mandibular distraction osteogenesis model

Abstract Introduction: Guided tissue regeneration (GTR) utilizes barrier materials to create environments that favor tissue regeneration. In the current study, we applied the principle of GTR to our rat mandibular distraction osteogenesis (DO) model in an attempt to enhance bone regeneration. Methods: Osteoconductive Gore Resolut XT membranes (a co-polymer of polylactic acid and polyglycolic acid) were used in this study. Twelve (n = 6 for each group) adult Sprague-Dawley rats underwent routine gradual distraction (GD, 5-day latency, 8-day distraction for a total of 4mm followed by 4-weeks of consolidation) and acute lengthening (AL, immediate lengthening to 4mm followed by 6-weeks of consolidation). An additional 10 animals underwent AL followed by application of Gore membranes (AL + GTR). Membranes were wrapped around the distraction gap in its entirety. All animals were sacrificed at 6 and 8 weeks post-operatively. Mandibles were analyzed with a Faxitron x-ray system, and routine H&E histology. Quantitative histomorphometric analyses were performed to compare relative bone formation between all three groups. Results: The GD group achieved complete bony union by 6 weeks. The AL group had only 28.27 ± 4.8% bone formation, while the AL + GTR group achieved 57.43 ± 16.5% bony union (∗p Conclusions: Our data demonstrates that GTR can significantly enhance osteogenesis. It may therefore have a role in accelerating bone regeneration in DO clinically.

Long-term clinical outcomes of abutments treated with guided tissue regeneration

Statement of problem. Guided tissue regeneration (GTR) is an efficacious and predictable treatment modality for deep intrabony defects around natural teeth and abutments. However, long-term prognosis of abutments treated with regeneration has to be proven. Purpose. This study investigated the long-term stability of clinical outcomes obtained with regeneration in strategically important abutments. Material and methods. Sixteen deep intrabony defects around strategically important abutments in 16 patients were treated according to the principles of GTR. After completion of initial periodontal therapy and placement of long-term provisional fixed partial dentures, nonresorbable membranes were applied. Membranes were removed after 6 weeks. All patients remained in a supervised recall program. Final fixed partial dentures were placed 1 year after surgery. Clinical outcomes were evaluated at 1 year and then 4 to 8 years after surgery. Results. Clinical attachment level gains of 5.3 ± 1.8 mm, reductions in pocket depth (6.1 ± 2 mm), and increases in the percentage of radiographic bone support (31% ± 18%) were observed at 1 year. At long-term follow-up visits, clinical attachment levels remained stable with respect to 1 year (–0.1 ± 0.6 mm; P =.4). The percentage of radiographic bone support slightly increased as compared with 1 year (1% ± 3%, P =.04), and pocket depths (0.8 ± 0.8 mm, P =.004). Conclusions. This study indicated that tooth support can be gained with GTR and maintained over time in patients recalled regularly. (J Prosthet Dent 1999;81:305-11.)

Guided tissue regeneration update

The ultimate goal of periodontal therapy is to restore periodontal tissues lost through disease or trauma. The most predictable way to accomplish this goal is by guided tissue regeneration (GTR). The principle of GTR is to give preference to certain cells to repopulate the wound area to form a new attachment apparatus. Clinically this is accomplished by placing a barrier over the defect thereby excluding gingival tissues from the wound during early healing. The first generation of GTR barriers were non-resorbable which implies that they have to be removed in a second surgical procedure. Resorbable barriers have recently been introduced, changing GTR into a single-step procedure. Periodontal defects that will predictably benefit from GTR therapy are intrabony, furcation class II and gingival recession defects. This paper reviews the scientific evidence of what can be achieved by GTR procedures for various periodontal defects as well as factors of importance to increase the predictability of a successful treatment outcome.

Treatment of interproximal angular defects by guided tissue regeneration: 1 year follow‐up

SUMMARY The periodontal regeneration of interproximal bone defects of the posterior teeth produced by guided tissue regeneration (GTR), with expanded Polytetrafluoroethylene barrier membranes and conventional therapy, was clinically evaluated in 20 intrabony periodontal defects in 10 patients. The material included the presence of at least two proximal angular lesions for the same patient, probing pocket depth ≥ 6 mm, bone defect depth ≥ 3 mm, and 2‐wall defects with crestal involvement relative to the tooth circumference ranging from 90 to 270°. Healing was clinically evaluated by surgical re‐entry of GTR‐treated sites (10 sites) and debridement only sites (10 sites) 1 year after initial surgery following a strict plaque control regimen. A significant correlation was observed between probing depth reduction, attachment gain and defect depth (test sites); there was increased bone fill in GTR‐treated lesions of 2.95 ± 1.3 mm corresponding to a 69.4% improvement compared to control sites, and 1–3 ± 1.0 mm corresponding to a 32% improvement (P &lt; 0.0039). The results demonstrated that bone regeneration is highly reliable, as compared to conventional therapy, in cases of severe periodontal bone loss from posterior teeth provided that the principles of GTR are applied.

Healing of osseous submucous cleft palates with guided bone regeneration.

The aim of this study was to develop an experimental model in rats of an osseous submucous cleft palate and to examine if bone regeneration can be achieved in such defects by the placement of membranes according to the principle of guided tissue regeneration (GTR). An osseous submucous cleft palate defect (5 mm x 2 mm) was created surgically in Wistar rats. Membranes of expanded polytetrafluoroethylene were placed so that they covered both the nasal and the palatal aspect of the defect before the palatal mucoperiosteal flap was repositioned and sutured. Histological analysis after seven weeks of healing showed that significantly more test animals (5/9) healed with newly formed bone and a suture-like tissue in the middle of the defects than controls treated without membranes (0/17). In specimens evaluated macroscopically after 12 weeks, the corresponding rates for the test group were 12/12 compared with 0/13. These observations indicate that an experimental model of an osseous submucous cleft palate can be established in rats, and that complete osseous healing and creation of a midpalatal suture-like tissue in the bony defect is favoured by the placement of membranes according to the principle of GTR.

The guided tissue regeneration principle in endodontic surgery: one‐year postoperative results of large periapical lesions

Twenty patients with large endodontic lesions, which failed to respond to conventional endodontic therapy, were selected for this study. The lesions had a radiographic diameter of at least 10 mm, were removed by periradicular surgery, before retrofilling the apices with either super EBA or dessicated zinc oxide-eugenol. In 10 test sites large e-PTFE membranes (Gortex) were placed to cover the lesions, while at the control sites the lesions were not covered before resuturing. Radio-graphic analysis of the lesions at 3, 6, 9 and 12 months revealed that lesions covered with the membranes healed quicker than the control lesions, and that the quality and quantity of the regenerated bone was superior when membranes were used. Results of the study indicate that guided tissue regeneration (GTR) principles can be effectively applied to the healing of large periapical lesions, especially in through-and-through lesions.

Healing Response of Human Buccal Gingival Recessions Treated With Expanded Polytetrafluoroethylene Membranes. A Retrospective Report

Twenty-four (24) deep wide buccal gingival recessions were treated with ePTFE membrane according to guided tissue regeneration principles (GTR). Factors affecting the surgical outcome of the regenerative procedure were retrospectively analyzed. In 16 cases, the barrier membrane was used in conjunction with tetracycline root conditioning and fibrin-fibronectin system application, and 8 cases were treated with the membrane alone. Healing response was evaluated 12 months after surgery. Since no difference was observed between the two treatment protocols, all available data were grouped. Mean recession depth was reduced from 4.6 mm to 1.3 mm postoperatively, which represents an average root coverage of 71.7%. Fifty percent (50%) of the cases showed clinical attachment gain greater than or equal to 4 mm and a mean increase of keratinized tissue of 1.0 mm was observed. Baseline recession depth and extent of membrane exposure at the reentry procedure significantly influenced the amount of newly-formed tissue under the membrane. Recession reduction positively correlated with the preoperative recession depth and the regenerated tissue gain. Treatment was also affected by tooth location, recession reduction, and attachment gain, being significantly greater in upper than lower archs. Results suggest that GTR technique represents a predictable procedure to improve the soft tissue conditions of deep mucogingival defects. Randomized controlled trials of other forms of management of mucogingival defects as compared to the GTR technique will be necessary to fully evaluate the utility of the GTR technique.

Membrane-guided bone regeneration. Segmental radius defects studied in the rabbit.

We tested the principle of guided tissue regeneration (GTR) for healing segmental long-bone defects. 7 mm (3 animals) or 10 mm (5 animals) long segmental defects were created in the diaphyses of both radii in 8 rabbits. The defect on one side was covered with a barrier membrane of expanded polytetrafluoroethylene membrane shaped as a tube, while the contralateral side with no membrane served as the control. Healing was followed with radiographs obtained repeatedly during a 13- (n 3) or 27- (n 5) week period. Thereafter, the animals were killed and ground sections of the defect sites were prepared for histologic examination. Radiographically, the control sites showed some early subperiosteal callus formation and nonunion of the defects after 6 weeks. The bone ends were rounded off and sealed with cortical bone. No major changes were noted after 6 weeks. At the test sites, subperiosteal bone formation at the bone ends was first observed radiographically at 2 weeks. At 9 weeks, a thin cortical bone bridged the defect along the inner surface of the membrane. Histologically, an interrupted line of thin, cortical bone was observed along the inner surface of the barrier membrane. Fatty bone marrow occupied the central and largest volume of the defect. We conclude that it seems possible to use the principle of GTR to accomplish bone union of segmental long-bone defects.

Remodelling of periodontal tissues adjacent to sites treated according to the principles of guided tissue regeneration (GTR).

The aim of the present study was to assess the remodelling of alveolar bone adjacent to periodontal sites following therapy according to the principles of guided tissue regeneration (GTR) using computer-assisted densitometric image analysis (CADIA), and to compare the radiographic results to traditional clinical parameters. As required for digital subtraction analyses, periodically reproducible radiographs were obtained using a modification of the Rinn System and individual acrylic bite blocks for periodical identical radiographs. Ideally, a digital subtraction image from a site where absolutely no change in density had occurred would show a perfect cancellation of the structures. An average grey level value of 128 (the middle of the digitizer grey level range set by software) would show up at each pixel. Areas with grey levels < 128 in the subtraction image would indicate loss in density and grey levels > 128 would indicate increase in density. Within the subtraction images, areas were defined using the cursor to draw "regions of interest" (ROI) projected on the bony defect exposed to GTR covering the crestal bone as well as the region of potential "bonefill". The mean, median, the standard deviation and range of the grey levels of pixels within a particular ROI were calculated. Similarly sized ROI were drawn in bone areas not exposed to the GTR procedure serving as controls. The differences in the mean grey levels of all pixels within a particular ROI between the baseline, 3 and 12 months images were calculated for documentation of gain or loss in density. From 14 patients, standardized radiographs were available from baseline, 3 months and 12 months postsurgically, depicting one infraosseous defect before and after treatment according to the principles of GTR. The densitometric changes observed in these defects were compared to the clinically assessed changes measured at the site with the deepest baseline pocket depth. A mean clinical attachment gain of 2.36 mm after 3 and 3.22 mm after 12 months was measured. This was associated with a mean reduction in the PPD amounting to 3.36 mm and 3.79 mm, respectively. The changes in the level of the FGM were rather small considering the deep original mean PPD of 7.07 mm. Over the first months, a mean recession of 1.14 mm was observed which was followed by a coronal displacement of 0.43 mm. With respect to the remodelling of the alveolar bone adjacent to the defects assessed by means of CADIA, the most pronounced changes occurred when comparing the baseline to the 12 months radiographs.(ABSTRACT TRUNCATED AT 400 WORDS)

Surgically modelled reduced ridge in the beagle dog

A reproducible surgical method for the production of reduced alveolar ridge in dogs using guided tissue regeneration principles is described. 3 defects resembling a reduced ridge were formed on both sides of the mandible in 4 dogs. In each of the dogs, a polytetrafluoroethylene membrane was placed on 4 defects, while 2 defects were covered by gingival flaps only. Half of the defects were allowed to heal for 6 weeks and half for 12 weeks. Bucco-lingual width measurements revealed healing up to the membrane. In the uncovered defects, the bony wall width increased during the 12-week healing period. Histological examination showed close adaptation between bone and membrane in well-sealed defects. In cases of incomplete sealing, connective tissue had penetrated into the defect, resulting in unpredictable bone healing. The use of guided tissue regeneration techniques is suggested as a valuable tool in creating experimentally reduced ridges.