Non-resorbable Barrier Membrane Research Articles

TENTING POLE ABUTMENT TECHNIQUE FOR THE EASY RECONSTRUCTION OF SEVERELY RESORBED ALVEOLAR RIDGES

Dental implant-supported oral rehabilitation is a widely used procedure in modern dentistry. However, implant placement on an atrophic alveolar ridge remains a challenging task due to the insufficient quantity and poor quality of bone. To address this issue, various surgical techniques have been employed to overcome vertical bone deficiency at implant sites, including guided bone regeneration (GBR) using non-resorbable barrier membranes or titanium mesh, onlay block grafting with intraosseous or extraosseous bone blocks, distraction osteogenesis, sandwich osteotomy with an interposition bone graft, and the ramus split bone technique. These surgical procedures are not without their drawbacks, however. They can be technically challenging, require longer surgery times, and result in significant postoperative patient discomfort. Additionally, because the implants are not placed simultaneously, the patient's edentulous healing period is prolonged. The utilization of tenting pole implants and abutments in conjunction with GBR procedure is a safe and effective technique for advanced ridge augmentation. This procedure has minimal complications. Future investigations are required to validate the effectiveness of this technique.

3D driven hard tissue augmentation based on reverse planning Reconstruction of an advanced, horizonto-vertical alveolar ridge defect: A case report

This case report presents a novel, 3D-driven reverse planning for surgical rehabilitation of an advanced alveolar ridge defect. Utilizing a completely digital workflow, alveolar ridge augmentation could virtually be simulated thus simplifying the surgical procedure. In this case report the digitally planned treatment of a severe horizontovertical alveolar ridge defect is presented. Preoperative cone-beam computed tomography (CBCT) scan was segmented using a semi-automatic segmentation technique in an open-source medical image processing software (3D Slicer) to develop virtual 3D models of dental and alveolar structures. Intraoral scan, bite registration was also acquired to generate a digital wax-up. Consequently, prosthetically ideal implant positions could be planned in 3D. Based on future implant positions, adequate amount of hard tissue augmentation could be planned virtually. Individualized form of the barrier membrane could be determined, allowing the additive manufacturing of a membrane cutting template for shaping the barrier membrane during surgery. The combination of a non-resorbable barrier membrane, tenting screws, and composite graft (50% xenograft, 50% autogenous bone) was utilized. A follow-up CBCT scan was taken after 9 months to determine volumetric and 3D morphological changes. After 9 months, a hard tissue gain of 0.81 cm 3 could be observed. During the 6-9 month healing period membrane exposition did not occur. Virtual planning and subsequent surgical simulation on 3D models is a novel method in “prosthetically driven” augmentation potentially reducing the duration of surgery and postoperative complications. However, further studies are necessary to drive any more conclusions.

Predictability and Clinical Stability of Barrier Membranes in Treatment of Periodontal Intrabony Defects: A Systematic Review and Meta-Analysis

The adjunctive use of GTR membranes helps us to achieve predictable periodontal regeneration. The aim of this systematic review was to evaluate and compare the treatment efficacy of resorbable versus non-resorbable barrier membranes used in guided tissue regeneration in the treatment of intrabony defects in chronic periodontitis patients. The following databases were searched: Medline, the Cochrane Central Register of Controlled Trails (CENTRAL), SCOPUS, EMBASE. Randomized clinical trials (RCTs) published in English languages over the past 25 years were included. The primary outcomes assessed were: change of probing pocket depth (PD), change in clinical attachment level (CAL) and gingival recession coverage (GRC), and intrabony defect fill (IBDF). A total of eight RCTs were included for systematic review. The outcome of GR at a six-month interval revealed a significant difference in treatment effect with a mean difference of 0.42, 95% CI [0.02, 0.81]; Z = 2.09, (p = 0.04) favouring the resorbable membrane group. The intrabony defect depth fill at a 12-month interval revealed a significant difference in treatment effect with MD of 0.79, p = 0.00001; favoring the resorbable membrane group. The resorbable membrane showed a significant improvement in gingival recession coverage and intrabony defect fill, owing to its advantage of avoiding the second surgical intervention.

Bioengineered membranes-past, present and future in tissue regeneration

Regeneration of soft and hard tissue defects, although not impossible, is not always a predictable outcome. Tissue Engineering has shown to be successful in regenerating such defects with the objective of development of a new functional tissue structure which is either scaffold-based or not. Currently, the barrier membranes are being used as a physical barrier for the growth of unwanted epithelial and connective tissue cells while promoting the growth of desired cells like those of periodontal ligament and bone cells, which is quite appreciable. But due to the various drawbacks of the conventional membranes, TE has led to the development of functionally enhanced membranes processed by a variety of techniques and materials which overcome the demerits of the currently used barrier membranes. The objectives of this review are to compare the resorbable and non-resorbable barrier membranes used in tissue regeneration, their properties, applications, merits and demerits and future advances.

Immunological Response to Nonresorbable Barrier Membranes Used for Guided Bone Regeneration and Formation of Pseudo Periosteum: a Narrative Review.

Here we review the knowledge on the local biological immunological response (formation of "pseudo periosteum" of the host) to two types of nonresorbable membranes used in the horizontal and vertical alveolar ridge augmentation: the titanium-reinforced polytetrafluoroethylene membrane and the titanium mesh membrane. A literature search was conducted including available in vitro, in vivo, and clinical studies on cellular and molecular immunological response to these two types of nonresorbable membranes, in particular the formation of "pseudo periosteum".

New Perspectives in the Use of Biomaterials for Periodontal Regeneration.

Periodontitis is a disease with a high prevalence among adults. If not treated, it can lead to loss of teeth. Periodontal therapy aims at maintaining patient’s teeth through infection control and correction of non-maintainable anatomies including—when possible—regeneration of lost periodontal tissues. The biological regenerative potential of the periodontium is high, and several biomaterials can be utilized to improve the outcome of periodontal therapy. Use of different natural and synthetic materials in the periodontal field has been studied for many years. The main materials used today in periodontology analyzed in this review are: Resorbable and non-resorbable barrier membranes; autogenous, allogeneic, xenogeneic, and alloplastic bone substitutes; biological agents, such as amelogenins; platelet-derived growth factor; bone morphogenic proteins; rh fibroblast growth factor 2; teriparatide hormone; platelet concentrates; and 3D scaffolds. With the development of new surgical techniques some concepts on periodontal regeneration that were strictly applied in the past seem to be not so critical today. This can have an impact on the materials that are needed when attempting to regenerate lost periodontal structures. This review aims at presenting a rationale behind the use of biomaterials in modern periodontal regeneration

Pure Titanium Membrane (Ultra - Ti®) in the Treatment of Periodontal Osseous Defects: A Split-Mouth Comparative Study.

Although many different types of Guided Tissue Regeneration (GTR) membranes (resorbable/non-resorbable, including titanium mesh) have been used in the field of Periodontics till now, but this is the first and only clinical study testing the effectiveness of an ultra thin pure Titanium Membrane (Ultra Ti) as a GTR membrane in infra-bony periodontal defects. To compare the efficacy of GTR in intra-bony defects with newly introduced non-resorbable barrier membrane, made of titanium called "Ultra-Ti ® GTR Membrane" versus open flap debridement. A prospective, randomized, controlled, clinical split mouth study was designed wherein each patient received both the control and test treatment. Two similar defects were selected in each of the 12 patients and were randomly assigned to one of the two treatments. Both the surgeries consisted of identical procedures except for the omission of the barrier membrane in the control sites. Full mouth Plaque Index (PI), Gingival Index (GI), Pocket Probing Depth (PPD) and Relative Attachment Level (RAL) were recorded before surgery and after 6 months and 9 months along with hard tissue measurements at the time of surgery and then at re-entry after 9 months. Radiographs were also taken before surgery and 9 months post operatively. Student's paired t-test and unpaired t-test (SPSS software version 9) were used to analyze the results. Nine months after treatment, the test defects gained 4.375 ± 1.189mm of RAL, while the control defects yielded a significantly lower RAL gain of 3.417 ± 0.996mm. Pocket reduction was also significantly higher in the test group (4.917 ± 0.996mm) when compared with the controls (3.83 ± 0.718mm). There was a significant bone fill (54.69% of defect fill) obtained in the test site, unlike the control site (8.91%). The present study demonstrated that GTR with "Ultra-Ti® GTR Membrane" resulted in a significant added benefit in comparison with open flap debridement.

A modified rabbit ulna defect model for evaluating periosteal substitutes in bone engineering: a pilot study.

The present work defines a modified critical size rabbit ulna defect model for bone regeneration in which a non-resorbable barrier membrane was used to separate the radius from the ulna to create a valid model for evaluation of tissue-engineered periosteal substitutes. Eight rabbits divided into two groups were used. Critical defects (15 mm) were made in the ulna completely eliminating periosteum. For group I, defects were filled with a nanohydroxyapatite poly(ester urethane) scaffold soaked in PBS and left as such (group Ia) or wrapped with a tissue-engineered periosteal substitute (group Ib). For group II, an expanded-polytetrafluoroethylene (e-PTFE) (GORE-TEX®) membrane was inserted around the radius then the defects received either scaffold alone (group IIa) or scaffold wrapped with periosteal substitute (group IIb). Animals were euthanized after 12–16 weeks, and bone regeneration was evaluated by radiography, computed microtomography (μCT), and histology. In the first group, we observed formation of radio-ulnar synostosis irrespective of the treatment. This was completely eliminated upon placement of the e-PTFE (GORE-TEX®) membrane in the second group of animals. In conclusion, modification of the model using a non-resorbable e-PTFE membrane to isolate the ulna from the radius was a valuable addition allowing for objective evaluation of the tissue-engineered periosteal substitute.

Guided Bone Regeneration for Socket Preservation in Molar Extraction Sites: Histomorphometric and 3D Computerized Tomography Analysis

Guided Bone Regeneration for Socket Preservation in Molar Extraction Sites: Histomorphometric and 3D Computerized Tomography Analysis

Effect of Enamel Matrix Derivative and Parathyroid Hormone on Bone Formation in Standardized Osseous Defects: An Experimental Study in Minipigs

Previous experimental studies have indicated that locally administered enamel matrix derivative (EMD) and parathyroid hormone (PTH) may have a stimulatory effect on bone formation. However, it is not clear if the positive effect of EMD is related to its effect on the periodontium as a whole or directly on the bone-forming cells. In addition, it is not known if the presentation of PTH by adding the amino acid sequence Arg-Gly-Asp (RGD) is essential for its osteopromotive effect. Local delivery of a bioactive substance at the right time and in the right concentration often constitutes a major challenge. Polyethylene glycol-based hydrogel (PEG) is a degradable vehicle developed for delivery of bioactive proteins. To enhance the mechanical stability of the PEG-bioactive substance complex, an osteoconductive bone substitute material is often needed. Three standard diameter monocortical bone defects were prepared bilaterally in the mandibles of 18 Göttingen minipigs. The six defects of each animal were grafted with 1) autogenous bone chips, 2) biphasic calcium phosphate bone substitute (BCP), 3) PEG + BCP, 4) EMD + PEG + BCP, 5) PTH + PEG + BCP, or 6) PTH-RGD + PEG + BCP. A non-resorbable barrier membrane was used to cover the defects. Three groups of six animals healed for 2, 4, and 8 weeks, respectively. There was no statistically significant effect of EMD, PTH, and PTH + RGD on bone formation compared to BCP and BCP + PEG. Particulated autografts showed the highest amount of new bone formation at all observation periods. The present study fails to demonstrate any stimulatory effect of EMD, PTH, or PTH + RGD in combination with an experimental PEG hydrogel and BCP on bone formation.

The effect of non-resorbable barrier membrane on the change of buccal and lingual alveolar bone in immediate implant placement into periapically infected extraction sockets

Purpose: Many researches showed loss of alveolar bone in fresh extraction socket and even in case of immediate implant placement. The aim of this study was to evaluate the effect of non-resorbable barrier membrane on the change of buccal and lingual alveolar bone in immediate implant placement into periapically infected extraction sockets. Materials and methods: Immediate implants were placed into artificially induced periapical lesion of mandibular premolars after complete debridement using buccal bone defect made by a 6mm trephine bur in 4 mongrel dogs. Before flap repositioning, a non-resorbable barrier membrane was placed on the buccal defect in the experimental group. No membrane was placed in the control group. In 12 weeks after placement, the dogs were sacrificed and undecalcified histologic specimens were prepared. The vertical distance from the smooth-rough surface interface(SRI) to gingiva, 1st bone contact and bone crest were measured in buccal and lingual side. The horizontal thicknesses of gingiva and bone at 0, 1, 2 and 3 mm below SRI were measured. Results: The buccal bone was resorbed more than lingual bone in both groups and there was statistical significance(p<0.05). The distances from SRI to 1st bone contact were 2.45±2.35 mm in experimental group and 4.49±3.10 mm in control group. In all vertical level, lingual bone was thicker than buccal bone(p<0.05). Conclusion: Buccal bone was reduced more than lingual bone in immediate implant placement into periapically infected extraction sockets. Placement of non-resorbable barrier membrane reduced the buccal bone resorption. However there was no statistical significance. (J Korean Acad Periodontol 2009;39:71-76)

In vitro evaluation of various bioabsorbable and nonresorbable barrier membranes for guided tissue regeneration

BackgroundDifferent types of bioabsorbable and nonresorbable membranes have been widely used for guided tissue regeneration (GTR) with its ultimate goal of regenerating lost periodontal structures. The purpose of the present study was to evaluate the biological effects of various bioabsorbable and nonresorbable membranes in cultures of primary human gingival fibroblasts (HGF), periodontal ligament fibroblasts (PDLF) and human osteoblast-like (HOB) cells in vitro.MethodsThree commercially available collagen membranes [TutoDent® (TD), Resodont® (RD) and BioGide® (BG)] as well as three nonresorbable polytetrafluoroethylene (PTFE) membranes [ACE (AC), Cytoplast® (CT) and TefGen-FD® (TG)] were tested. Cells plated on culture dishes (CD) served as positive controls. The effect of the barrier membranes on HGF, PDLF as well as HOB cells was assessed by the Alamar Blue fluorometric proliferation assay after 1, 2.5, 4, 24 and 48 h time periods. The structural and morphological properties of the membranes were evaluated by scanning electron microscopy (SEM).ResultsThe results showed that of the six barriers tested, TD and RD demonstrated the highest rate of HGF proliferation at both earlier (1 h) and later (48 h) time periods (P < 0.001) compared to all other tested barriers and CD. Similarly, TD, RD and BG had significantly higher numbers of cells at all time periods when compared with the positive control in PDLF culture (P ≤ 0.001). In HOB cell culture, the highest rate of cell proliferation was also calculated for TD at all time periods (P < 0.001). SEM observations demonstrated a microporous structure of all collagen membranes, with a compact top surface and a porous bottom surface, whereas the nonresorbable PTFE membranes demonstrated a homogenous structure with a symmetric dense skin layer.ConclusionResults from the present study suggested that GTR membrane materials, per se, may influence cell proliferation in the process of periodontal tissue/bone regeneration. Among the six membranes examined, the bioabsorbable membranes demonstrated to be more suitable to stimulate cellular proliferation compared to nonresorbable PTFE membranes.

Vascularization of an Unsuccessful Case Following Guided Bone Regeneration.

This study evaluated a case which was unsuccessful after guided bone regeneration (GBR) operation with non-resorbable barrier membranes in the extraction socket of a beagle dog. To clarify the relationship between bone and vascular regeneration, a vascular resin cast model was observed under a scanning electron microscope (SEM).At 30 days post-operation, vessels from the periosteum were seen migrating to the socket through the gap between the membrane and the bone wall. The regenerated bone height was no higher than that of the pre-existing alveolar crest.At 60 days post-operation, the height of the regenerated bone was in accordance with that of the Pre-existing bone. A vascular network of granulation tissue was seen between the membrane and the upper margin of the alveolar bone. This vascular network consisted of a densely arranged vascular loop. The tracing of the circulatory pathway revealed that this network was composed of arteries from the alveolar bone marrow and veins of large diameter, which drained to the oral mucosa. The surface of a granulation tissue vessel showed a rough configuration. Resin was found to be leaking from the vascular loops.The study of this unsuccessful case clearly showed that the membrane was neither in close contact to the surrounding bone wall nor sufficiently supported by it. This resulted in an ingrowth of vessels from the periosteum to the socket. Consequently, there was no increase in bone height growth and new bone apposition did not occur. To succeed with GBR, it is essential that vascularization of the periosteum occur and that the membrane gradually cover and seal the extraction socket.

Effects of barrier membranes on bone resorption and implant stability in onlay bone grafts. An experimental study.

The objective of the present report was to study the effects of barrier membranes on bone resorption and implant stability in a rabbit onlay bone graft model, using resonance frequency analysis, coordinate measurements on plaster models, removal torque measurements and histology. Disc-shaped bone grafts were harvested from the calvarium and placed with titanium implants in the proximal tibial metaphyses of 9 rabbits. On one side (test) the bone graft/implant was covered by an e-PTFE barrier, while the contralateral side was not covered by a membrane and served as control. Three animals were sacrificed after 8 weeks for histology. In 6 animals the membranes were removed after 8 weeks and the animals were followed for an additional period of 16 weeks. Implant stability and bone height around the implants was assessed for the test and control sides at Day 0 and 8, 16 and 24 weeks postoperatively. Removal torque tests were performed after 24 weeks. The results showed an increase in volume of the bone graft on the test side as long as the barrier membrane was in place. However, after removal of the membrane at 8 weeks the resorption rate was higher on the test side compared to the control side, resulting in a similar bone height after 24 weeks. There were no statistically significant differences in implant stability between the test and control sides at any time point, as measured with resonance frequency analysis. Additionally, no statistically significant differences were found between the test and control sides after 24 weeks, using removal torque measurements, coordinate measurements and histomorphometric evaluation. Thus, in this experimental model, the use of non-resorbable barrier membranes did not improve the stability of implants simultaneously placed with onlay bone grafts. Moreover, extensive resorption of the grafted bone was seen after barrier removal, which resulted in similar bone graft volume for the test and control sides at the end of the observation period.

The relationship among CD 4, CD 8, and MRC OX-12 antigen expression in 4NQO induced premalignant lesion of rat

The relationship among CD 4, CD 8, and MRC OX-12 antigen expression in 4NQO induced premalignant lesion of rat