Guided Tissue Regeneration Barrier Research Articles

Treatment of furcation defects using various bone grafts and guided tissue regeneration membranes: A review on single-center institutional studies

Abstract Bone formation in class II furcation is least due to the morphology of the root in case of multirooted teeth performed by conventional procedure. Hence, various bone grafts with membranes have been tried in the current study to evaluate its efficacy by comparing test and control groups. This collection of research from a single center presents a bone graft and guided tissue regeneration (GTR) membrane-based furcation therapy. Bio-Oss and Bio-Gide, PerioGlas and Atrisorb, Periobone G and Resolut XT, as well as PepGen P-15 and Atrisorb, were among the bone graft materials used, both with and without the GTR barrier. Patients were divided into four groups based on the periodontal regenerative materials used. A periodontal flap procedure was performed where periodontal intraosseous defect along with furcation defects were present. The results show that the bone formation in the furcation area was more with Group C (Periobone G and Resolut XT) as compared to the least amount of bone formation in Group A (Bio-Oss and Bio-Gide) in the test group, and this same group shows least bone formation in control. To conclude, clinical outcomes observed with the combined use of Atrisorb as a GTR barrier and PerioGlas as a bone graft material improved the clinical measurements of furcation defect depth compared to the use of PerioGlas alone.

Bibliometric analysis of top-cited articles in Journal of Dental Sciences

Background/purposeBibliometric analysis is a method for quantifying the article distribution, impact, and performance. The purpose of this study was to identify the most top-cited articles published in Journal of Dental Sciences (JDS) and further analyze their main characteristics. Materials and methodsWeb of Science, Journal Citation Reports database was searched to retrieve the most-cited articles in JDS published from 2007 to July 31, 2022. Among the included top-cited articles, the following parameters were recorded and analyzed: article title, article type, year, country, number of citations, and average citations pre year. Microsoft Excel was applied for the descriptive bibliometric analysis. Results41 top-cited articles were filtered from total 1165 JDS articles in Web of Science database. The results showed that 41 top-cited articles were cited between 20 and 186 times from Journal Citation Reports. Most of the article types are original article (28/41, 68.29%) following by review article (7/41, 17.07%). The majority of articles were originated from Taiwan (23/41, 56.10%). The top 4 most cited articles were relative to the research topic on COVID-19, lateral canal, guided-tissue regeneration barriers, and platelet-rich fibrin, respectively. However, articles analyzed by the average citations per year since publication were focused on COVID-19 followed by artificial intelligence. ConclusionThis bibliometric analysis illustrates the progress and trend of researches in JDS. The results may also offer a reference for recognizing the hot issues with the most citations in JDS.

Polylactic Acid Printed Scaffold on Collagen Membrane: Physical, Chemical Analysis and the Report of 2 Clinical Cases

The bovine collagen membrane LUMINA-COAT (Reg.ANVISA nº80522420002) of the company CRITÉRIA BIOMATERIAS LTDA, membrane basically composed of type 1 collagen, biocompatible and sterile for medicine and dentistry use, had one of its surfaces coated with a polylactic acid (PLA) sheet. Sterile and previously shaped for adjustment on grafted bone site, this device was applied in 2 clinical cases of bone regeneration in the function of guided tissue regeneration barrier.

Preparation of acetylated chitosan/carbonated hydroxyapatite composite barriers for guided bone regeneration

Biopolymer/bioceramic composites were prepared by blending acetylated chitosan (ACS) with carbonated nano-size hydroxyapatite (CHAP) for use as a guided tissue regeneration barrier. The carbonate group of CHAP was a partial substitution of the hydroxyl group and/or phosphate group of hydroxyapatite by sintering with carbon dioxide. Chitosan/CHAP composites were acetylated with acetic anhydride to form the ACS/CHAP composites. The compositions and properties of the composites were confirmed by Fourier transform infrared spectroscopy, inductively coupled plasma mass spectrometry, zeta potential analysis, X-ray diffraction analysis, universal testing machine analysis, scanning electron microscopy, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, etc. The surface energies of the composites were increased by carbonation and acetylation. The acetylation of chitosan increased the lysozyme degradation of the composite. The carbonation of hydroxyapatite significantly improved the viability of osteoblast-like cell on the composite. The high viability and intact phenotype of cell occurred on composite with ACS/CHAP ratio of 50/50, which had sufficient elastic modulus for a guided bone regeneration barrier.

Membranes for periodontal tissues regeneration

The complexity of the tissues and the healing process of the periodontal wound turn the development of therapies for the predictable regeneration of functional periodontal tissues, a challenging exercise. In the last decades, the guided tissue regeneration (GTR) emerged as a strategy to drive the innate regenerative properties of the tissues involved in the periodontal apparatus (gingiva, tooth root, periodontal ligament and alveolar bone). GTR therapies have shown that the use of membrane barriers that are occlusive for gingival cell migration and that provide wound stability and space provision for the first intentional repair promoted by cells originated from periodontal tissues can partially restore the primitive anatomy and function of the periodontium. This paper describes examples of the variety of non-degradable and degradable membrane barriers developed for GTR approaches. During the last 20 years, the research has evolved to develop GTR barriers that avoid the recurrent problems related with the early membrane exposure and the recurrent infections. Furthermore, the association of the GTR to tissue engineering principles, such as the inclusion of biochemical cues and new architectures as well as the association with stem cells of different niches, has given rise to new materials with improved properties and biological performance.

Antimicrobial Activity of Minocycline-Loaded Genipin-Crosslinked Nano-Fibrous Chitosan Mats for Guided Tissue Regeneration

Antimicrobial delivery has been advocated for guided tissue regeneration (GTR) or guided bone regeneration (GBR) therapies involving patients with aggressive or unresolved periodontitis/peri-implantitis. Electrospun chitosan membranes demonstrate several advantages over traditional GTR barrier membranes because they stimulate healing, mimic the topology of the extracellular matrix, and allow for diffusion of nutrients and wastes into/out of the graft site, and were shown to stimulate bone formation in a rabbit calvarial criticalsize defect model. Previously, we have shown improvements in mechanical properties and degradation kinetics by crosslinking electrospun membranes with 5 mM or 10 mM genipin. We have also demonstrated the ability of elecrospun chitosan membranes to inhibit lippopolysaccharide (LPS)-induced monocyte activation. In this study, minocycline was incorporated into the chitosan membrane by passive absorption at 5 or 10 mg/mL. The minocycline-loaded membranes and control membranes (carrier only) were tested against Porphyromonas gingivalis (P. gingivalis) by repeated zone of inhibition (ZOI) measurements. Testing showed that uncrosslinked and genipin-crosslinked membranes have similar capacity to absorb aqueous solutions (swelling ratio 1.7 - 2.2). Minocycline loading resulted in bacterial inhibition for up to 8 days from crosslinked membranes (with 11 mm initial ZOI) whereas uncrosslinked membranes loaded with minocycline only inhibited bacteria for 4 days (with 8 mm initial ZOI). These in vitro results suggest that genipin-crosslinked electrospun chitosan membranes loaded with minocycline may be able to reduce early bacterial contamination of GTR graft sites.

Preparation of chitosan/hydroxyapatite guided membrane used for periodontal tissue regeneration

In an effort to develop biomaterials to meet guided tissue regeneration (GTR) standards for periodontal tissue recovery, a homogeneous and transparent chitosan (CS)/hydroxyapatite (HA) membrane with potential applications as GTR barrier in periodontal therapy has been prepared via in situ compositing. The membrane has been designed to have a smooth-rough asymmetric structure that meets the demand for GTR. Component and morphology of the membrane are characterized by XRD and SEM. It can be indicated that HA was in situ synthesized uniformly in the CS membrane. Mechanical experiments of the membranes with various HA contents show that their tensile strengths are adequate for periodontal therapy. Biological properties of the membrane have been performed by cell toxicity assays, hemolysis tests and animal experiments. Results indicate that the membrane has good biocompatibility and inductive effect for cell growth. Therefore this membrane can be potentially applied as GTR barrier membrane for periodontal tissue regeneration.

Biological properties of a biomimetic membrane for guided tissue regeneration: a study in rat calvarial defects

The biological properties of nano-hydroxyapatite/polyamide (nHA/PA66) membrane as a guided tissue regeneration barrier were investigated based on a critical-size calvarial defect model. Thirty-six Sprague-Dawley rats were divided into four groups: nHA/PA66 membranes, control treated with expanded polytetrafluoroethylene (e-PTFE) membranes, control treated with PA membranes and blank. Bone regeneration in each group was evaluated using morphological, serological, radiographic and histological techniques at 1, 4 and 8 weeks, respectively, post-operation. Slight degradation of nHA/PA66 membranes was observed by a scanning electron microscope (SEM) at 4 and 8 weeks. The serum alkaline phosphatase level and the integral optical density of neo-bone were significantly higher in the nHA/PA66 group than those in the PA group and blank (P<0.05). Radiographic and histological analysis showed a fully closed cranial defect for both the nHA/PA66 group and the e-PTFE group at 8 weeks. No remarkable difference was found between the nHA/PA66 group and the e-PTFE group at each time interval. nHA/PA66 membrane promoted bone regeneration as effectively as conventional e-PTFE membrane. Based on a rat study, nHA/PA66 membrane provides a promising alternative to e-PTFE membrane due to the absence of requirement for a second surgery.

Efficacy of Combined Regenerative Treatments in Human Mandibular Class II Furcation Defects

The treatment of molar furcation defects remains a considerable challenge in clinical practice. The degree of success in the management of furcation involvement is highly variable and inversely related to initial probing depth (PD) measurements in these lesions. The identification of clinical measurements influential to the treatment outcomes is critical to optimize the results of surgical periodontal therapy. Therefore, the objective of this study was to evaluate the clinical response of mandibular buccal Class II furcation lesions to a combined regenerative treatment modality. Sixty patients were divided into two (n = 30) treatment groups. An experimental combined regenerative therapy (ET) was compared to open flap debridement (OFD). The ET was a combination of a composite graft consisting of bioabsorbable hydroxyapatite and tetracycline (3:1), a guided tissue regeneration barrier, and a coronally advanced flap. The clinical variables evaluated were plaque, bleeding on probing, gingival recession, PD, vertical attachment level (VAL), horizontal attachment level (HAL), furcation vertical height, furcation horizontal depth, and the amount of tissue under the barrier membrane at uncovering. Reevaluation was performed 12 months after the surgical procedure. Both treatments resulted in improvements in all clinical variables evaluated. Postoperative measurements revealed a reduction in PD of 3.65 +/- 0.6 mm and 0.60 +/- 1.0 mm; VAL gains of 3.05 +/- 0.6 mm and 0.65 +/- 0.6 mm and HAL gains of 3.45 +/- 1.3 mm and 0.55 +/- 0.7 mm in the ET and OFD groups, respectively. In the ET group, significant positive correlations were found between baseline PD and PD reduction at 12 months, and the initial VAL correlated positively with PD reduction and HAL gain. The horizontal furcation depth and amount of tissue formed under the membrane at uncovering correlated positively with PD reduction and HAL and VAL gains. For the OFD group, the initial PD correlated positively with PD reduction and VAL and HAL gains and correlated negatively with recession. Initial VAL correlated positively with PD reductions and VAL and HAL gains. The initial HAL correlated negatively with recession at 12 months. ET exhibited significantly better clinical results, with more PD reduction, HAL and VAL gains, and a higher frequency of furcation closure compared to OFD and showed promise as a regenerative treatment technique. The ability to predict a response to treatment based upon pretreatment parameters was not consistent between groups; thus, prediction of treatment outcomes based on pretreatment measurements should be carefully evaluated for each treatment modality.

Regeneration of Degree II Furcation Defects With a 4% Doxycycline Hyclate Bioabsorbable Barrier

Bacterial contamination of a healing regenerative site has been shown to affect the response to therapy adversely. Doxycycline possesses antibacterial properties as well as other biologic actions that may result in an increased production and maintenance of collagen and bone. The purpose of this study was to assess if the sustained release of 4% doxycycline through a bioabsorbable barrier would enhance the regenerative outcomes of healing furcation sites. Individuals with a single degree II furcation defect in a mandibular molar participated. They were assigned randomly to one of three treatment groups: poly(DL-lactide) polylactic acid (PLA) barrier containing 4% doxycycline hyclate + demineralized freeze-dried bone allograft (DFDBA) (BG+PDox); poly(DL-lactide) PLA barrier without doxycycline + DFDBA (BG+P); or DFDBA alone (BG). Clinical parameters included vertical probing depth (VPD), vertical clinical attachment level (VCAL), gingival recession, and horizontal probing depth (HPD). Intrasurgical measurements to calculate vertical and horizontal furcation fill were obtained at the time of surgery (baseline) and during a reentry procedure 9 months later. Statistical tests were used to assess changes in the clinical and surgical parameters before and after treatment among groups and within each group. Mean changes at 9 months for all groups yielded VPD reductions and VCAL gains. However, no significant difference was noted for the group that was treated with 4% doxycycline barrier compared to the other two groups. Vertical bone fill was 0.89, 1.44, and 1.18 mm for the BG+PDox, BG+P, and BG groups, respectively. Furcation horizontal bone was 2.33, 2.11, and 1.18 mm for the BG+PDox, BG+P, and BG groups, respectively. Addition of doxycycline to the guided tissue regeneration barrier did not enhance treatment outcomes compared to the non-antibiotic-loaded barrier or bone graft alone. All treatment modalities provided similar improvement in clinical and intrasurgical parameters.

Preparation and immobilization of soluble eggshell membrane protein on the electrospun nanofibers to enhance cell adhesion and growth

Nonwoven poly(epsilon-caprolactone) (PCL) nanofibers were prepared by electrospinning technology, and a novel natural bioactive material, soluble eggshell membrane protein (SEP), which is made from natural eggshell membrane (ESM), was then immobilized on the nanofibers after the surface modification. The SEP-immobilized fibrous mat was observed and characterized using scanning electron microscopy (SEM), contact angle measurement, Fourier transform infrared attenuated total reflection spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and tensile mechanical tests. Then the primary human dermal fibroblasts (HDFs) were cultured to evaluate the in vitro biocompatibility of SEP-grafted electrospun PCL nanofibers. The results confirmed the successful immobilization of SEP on the nanofibers and also indicated that the hydrophilicity of the PCL nanofibers has been greatly improved by the SEP grafting. The results of MTT testing, SEM, and laser scanning confocal microscope (LSCM) showed that SEP immobilization can obviously enhance the attachment, spreading, and proliferation of human dermal fibroblasts (HDFs) compared with the pristine material. The SEP-grafted PCL nanofibers can be expected to biomimic and regenerate the natural structure of eggshell membrane and to be a potential material for tissue engineering scaffold and guided tissue regeneration barrier membrane.

Surgical guided tissue regeneration treatment of advanced periodontal defects: a 5‐year follow‐up study

To study the 5-year outcome of combined use of guided tissue regeneration (GTR) barriers and bovine bone in advanced periodontal defects. In each of 24 patients, one defect was surgically exposed, debrided, filled with bovine bone, and covered with a bioresorbable barrier. Re-examinations were made after 1, 3, and 5 years. Average full-mouth plaque scores (FMPS) were 14.5% at baseline and 10.7%, 9.8%, and 18.9% after 1, 3, and 5 years, respectively. Mean probing pocket depth (PPD) was 10.0 mm at baseline. Mean PPD reduction was 5.2 mm after 1 year, 5.6 mm after 3 years, and 5.3 mm after 5 years. Mean gingival recession was 1.0 mm after 1 year, 1.6 mm after 3 years, and 1.3 mm after 5 years. Mean gain in clinical attachment level (CAL) was 4.2 mm at the 1-year, 4.1 mm at the 3-year, and 4.3 mm at the 5-year examination. Smoking significantly influenced CAL change at all re-examinations. FMPS were significantly correlated with radiographic defect depth at the 5-year examination and CAL with smoking and FMPS at the 3-year examination. Advanced periodontal defects can be successfully treated with the combined use of GTR barriers and bovine bone to substantially reduce PPD and achieve a stable, long-term gain of CAL.

Enamel Matrix Derivative and Guided Tissue Regeneration in the Treatment of Dehiscence‐Type Defects: A Histomorphometric Study in Dogs

The goal of this investigation was to histologically and histometrically evaluate the healing process of dehiscence-type defects treated by enamel matrix derivative (EMD) and/or guided tissue regeneration (GTR). Seven mongrel dogs were used. Buccal osseous dehiscences were surgically created on the mesial roots of the mandibular third and fourth premolars. The defects were exposed to plaque accumulation for 3 months. After this period, the defects were randomly assigned to one of the treatments: open flap debridement (OFD), enamel matrix derivative (EMD), GTR with bioabsorbable membrane (GTR), and the combination of both procedures (EMD + GTR). After 4 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included gingival recession, epithelial length, connective tissue adaptation, new cementum, and new bone. A superior length of new cementum was observed in the sites treated by EMD (3.7 mm) and EMD + GTR (3.8 mm) in comparison with OFD (2.4 mm) (P < 0.05). No statistically significant differences were found in the remaining histometric parameters. Within the limits of this study, it can be concluded that EMD alone or in combination with GTR barriers may effectively promote new cementum formation. The combination of both therapies may not provide additional benefits.

Guided tissue regeneration for the treatment of periodontal intrabony and furcation defects. A systematic review.

Many clinical studies have demonstrated that guided tissue regeneration (GTR) is a successful treatment modality of periodontal reconstructive surgery and it has become an accepted procedure in most periodontal practices. The purpose of this structured review was to assess the efficacy of guided tissue regeneration (GTR) procedures in patients with periodontal osseous defects compared with surgical controls on clinical, radiographic, adverse, and patient-centered outcomes. It extends the scope of previous GTR systematic reviews, which were limited to randomized controlled studies, by the scope of outcome measures examined, and the duration of the study. In patients with periodontal osseous defects, what is the effect of physical barriers compared with surgical controls on clinical, radiographic, adverse, and patient-centered outcomes? An electronic search of the Cochrane Oral Health Group Trials Register and MEDLINE databases was performed. Manual searching of journals included Journal of Clinical Periodontology, Journal of Periodontology, and Journal of Periodontal Research up to January 2002. This manual search also included review of relevant bibliographies. Two manufacturers of GTR devices were contacted regarding unpublished data. Studies were selected for review if the evidence level was 3B (cohort) or above, at least 6 months duration, and compared a test GTR intervention with a surgical control. Studies with experimental design problems; histologic or microbiological investigations; or those with outcome measurements, study populations, or study duration not consistent with the inclusion criteria were excluded. Primary outcome measures for intrabony defects were: clinical attachment level (CAL) gain, probing depth reduction (PD), gingival recession (REC) reduction; for furcation defects: vertical probing attachment level (VPAL) gain, vertical probing depth reduction (VPD), horizontal probing depth reduction (HPD), horizontal open probing attachment level gain (HOPA), and vertical open probing attachment level gain (VOPA). Meta-analysis was performed to compare GTR procedures to other surgical treatments and to examine the resulting clinical outcomes. 1. For the primary outcome variables, in both intrabony-defect and furcation-defect studies, GTR was favored over open flap debridement (OFD) therapies (P < 0.0001). 2. No differences were detected among barrier types, but barrier types could explain some heterogeneity in the results. 3. Augmentation of the GTR barrier with a particulate graft enhanced VPD (P < 0.05), VPAL, and HOPA, but none of the intrabony outcomes. Overall, GTR is consistently more effective than OFD in the gain of clinical attachment and probing depth reduction in the treatment of intrabony and furcation defects.

Enzymatic degradation of collagen‐guided tissue regeneration membranes by periodontal bacteria

Bacterial infection in the vicinity of guided tissue regeneration barrier membranes was shown to have a negative effect on the clinical outcomes of this increasingly used technique. Several oral and specifically periodontal bacteria were shown to adhere to such membranes in vivo and in vitro with a higher affinity to membranes constructed from collagen. The present study examined the role of periodontal bacteria and their enzymes in the degradation of commercially used collagen membranes. Degradation of two collagen membranes [Biomend (Calcitek, Colla-Tec Inc., Plainsboro, NJ) and Bio-Gide (Geistlich Biomaterials, Wolhousen, Switzerland)] labeled by fluorescein isothiocyanate was examined by measuring soluble fluorescence. Porphyromonas gingivalis, Treponema denticola and Actinobacillus actinomycetemcomitans and their enzymes were evaluated. Collagenase from Clostridium hystolyticum was used as a positive control. While whole cells of P. gingivalis were able to degrade both types of membranes, T. denticola could degrade Bio-Gide membranes only and A. actinomycetemcomitans whole cells could degrade none of the membranes. Fractionation of P. gingivalis cells revealed that cell membrane associated proteases were responsible for the degradation of the two collagen membranes. In T. denticola, the purified major phenylalanine protease was found to be responsible for the degradation of Bio-Gide membranes. These results suggest that proteolytic bacterial enzymes may take part in the degradation of collagen barrier membranes used for guided tissue regeneration.

Flow cytometry analysis of guided tissue regeneration-associated human periodontal cells.

Expanded polytetrafluoroethylene (ePTFE) barrier membranes have been widely used for guided tissue regeneration (GTR) of the human periodontal ligament (PL). However, the precise cellular and molecular events involved in the re-growth of the new tissue are still unclear. Retrieved membranes and the newly-regenerated soft tissue (RT) underlying the membranes were used to examine the cells associated with GTR compared with normal human PL and gingival cells. Flow cytometry (FCM) was used, for the first time, to analyze the spindle-shaped fibroblast-like cells which were adherent to these membranes and the cells which grew out of the RT. The results showed that the membrane-associated (M) cells had the lowest rate of proliferation and appeared to be larger and more granular than the other types of cell. Moreover, both the M- and RT-derived cells were found to express higher levels of the extracellular matrix (ECM) proteins collagen type 1, fibronectin, tenascin, and decorin. In addition, evidence based on FCM profiles identified distinct sub-populations of GTR cells in which fibronectin expression was markedly up-regulated compared with normal PL cells and which also differed in size and granularity. The results of this study show that cells associated with GTR barrier membranes and with the underlying tissue appear to have distinct phenotypic and functional activities consistent with the production of new periodontal connective tissue and periodontal regeneration.

Treatment of Class II Furcation Involvements in Humans with Bioabsorbable Guided Tissue Regeneration Barriers

Treatment of Class II Furcation Involvements in Humans with Bioabsorbable Guided Tissue Regeneration Barriers

Biodegradation and biocompatibility of a guided tissue regeneration barrier membrane formed from a liquid polymer material.

Biodegradable barrier films were made by coagulating a solution of poly(DL-lactide) in N-methyl-2-pyrrolidone on porous polyethylene pads wetted with saline solution. The semisolid films were cut into 10 x 10 mm barriers and implanted subcutaneously in rabbits. At monthly intervals, the polymer implant sites were compared histologically to those implanted with USP negative control plastic. The polymer films were retrieved from the surrounding tissue, dried, weighed, and the changes in molecular weight determined using gel permeation chromatography. The molecular weight of the polymer decreased at a relatively constant rate over 5 months; however, no significant mass loss occurred until 5 months postimplantation. Also, no distinct histological differences were noted between the polymer barrier and the control plastic sites until 6 months when histiocytes and multinucleated giant cells showed a modest increase around fragmented polymer films. Similar barrier films also were fitted over naturally occurring buccal dehiscence defects in beagle dogs and the tissue sites compared histologically at 6 months to sham-operated control sites. New bone and dense connective tissues closely approximated segments of the remaining polymer and demonstrated the biocompatibility of the biodegradable films. Histomorphometric analyses of treated sites compared to sham controls showed that the polymer barrier is effective in promoting bone and cementum regeneration in periodontal defects in dogs.

Biodegradation and biocompatibility of a guided tissue regeneration barrier membrane formed from a liquid polymer material

Biodegradable barrier films were made by coagulating a solution of poly(DL-lactide) in N-methyl-2-pyrrolidone on porous polyethylene pads wetted with saline solution. The semisolid films were cut into 10 × 10 mm barriers and implanted subcutaneously in rabbits. At monthly intervals, the polymer implant sites were compared histologically to those implanted with USP negative control plastic. The polymer films were retrieved from the surrounding tissue, dried, weighed, and the changes in molecular weight determined using gel permeation chromatography. The molecular weight of the polymer decreased at a relatively constant rate over 5 months; however, no significant mass loss occurred until 5 months postimplantation. Also, no distinct histological differences were noted between the polymer barrier and the control plastic sites until 6 months when histiocytes and multinucleated giant cells showed a modest increase around fragmented polymer films. Similar barrier films also were fitted over naturally occurring buccal dehiscence defects in beagle dogs and the tissue sites compared histologically at 6 months to sham-operated control sites. New bone and dense connective tissues closely approximated segments of the remaining polymer and demonstrated the biocompatibility of the biodegradable films. Histomorphometric analyses of treated sites compared to sham controls showed that the polymer barrier is effective in promoting bone and cementum regeneration in periodontal defects in dogs. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 42, 303–311, 1998.

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.