Search

Purpose: To compare the clinical effectiveness of three different devices used in guided bone regeneration procedures for partially atrophic arches., Materials and Methods: A randomised controlled trial with three parallel arms was conducted. The study evaluated titanium-reinforced polytetrafluoroethylene membrane (PTFE group), semi-occlusive CAD/CAM titanium mesh (mesh group) and occlusive CAD/CAM titanium foil (foil group) in terms of surgical outcomes and complications as well as surgical times and surgeon satisfaction in 27 guided bone regeneration procedures, presenting results from 1 year post-implant placement., Results: Complications occurred in seven patients. No significant difference was found between the groups in terms of the occurrence of complications (P = 0.51), device exposure (P = 0.12) and implant failure (P = 0.650). Surgeon satisfaction varied significantly, with the PTFE group differing from the mesh (P = 0.003) and foil groups (P 0.001), but not between meshes and foils (P = 0.172). Surgical times also differed significantly, with longer times for PTFE membranes compared to meshes (P 0.001) and foils (P = 0.006), but with no difference between meshes and foils (P = 0.308). The mean reconstructed bone volume was 1269.55 ± 561.08 mm3, with no significant difference observed between the three groups (P = 0.815). There was also no significant difference for mean maximum height (6.72 mm, P = 0.867) and width (7.69 mm, P = 0.998). The mean marginal bone loss at 1 year after implant placement was 0.59 ± 0.27 mm., Conclusions: Although this study provides valuable insights into the potential benefits of using different types of CAD/CAM devices, further research with larger sample sizes and longer follow-up periods is warranted to validate these findings., Conflict-Of-Interest Statement: The authors declare there are no conflicts of interest relating to this study.

Chronic periodontal is a very common infection that instigates the destruction of oral tissue, and for its treatment, it is necessary to minimize the infection and the defects regeneration. Periodontium consists of four types of tissues: (a) cementum, (b) periodontal ligament, (c) gingiva, and 4) alveolar bone. In separated cavities, regenerative process also allows various cell proliferations. Guided tissue regeneration (GTR) is a potential procedure that favors periodontal regrowth; however, some limitations (such as ineffective hemostatic property, poor mechanical property, and improper biodegradation) are also associated with it. This review mainly emphasizes on the following areas: (a) a summarized overview of the periodontium and its immunological situations, (b) recently utilized treatments for regeneration of distinctive periodontal tissues; (c) an overview of GTR membranes available commercially, and the latest developments on the characterization and processing of GTR membrane material; and 4) the function of the different non-polymeric/polymeric materials, which are acting as drug carriers, antibacterial agents, nanoparticles, and periodontal barrier membranes to prevent periodontal inflammation and to improve the strength of the GTR membrane., (© 2021 John Wiley & Sons Ltd.)

Guided tissue regeneration procedures to treat periodontitis lesions making use of polytetrafluoroethylene (PTFE) membranes exhibit large variability in their surgical outcomes, due to bacterial infection following implantation. This work reports on a facile method to obtain antimicrobial coatings for such PTFE membranes, by exploiting a mussel-inspired approach and in-situ formation of silver nanoparticles (AgNPs). PTFE films were initially coated with self-polymerized 3,4-dihydroxy-DL-phenylalanine (DOPA) (PTFE-DOPA), then incubated with AgNO 3 solution. In the presence of catechol moieties, Ag + ions reduced into Ag 0 , forming AgNPs of around 68 nm in the polyDOPA coating on PTFE membranes (PTFE-DOPA-Ag). The x-ray photoelectron spectroscopy, atomic force microscopy and scanning electron microscopy analyses indicated that the AgNPs were distributed quite homogeneously in the polymeric membrane. The antimicrobial ability of PTFE-DOPA-Ag membranes against Staphylococcus aureus and Escherichia coli was assessed. In vitro cell assay using NIH 3T3 fibroblasts showed that, although cells were adhered to PTFE-DOPA-Ag membranes, their viability and proliferation were limited demonstrating again the antibacterial activities of PTFE-DOPA-Ag membranes. This work provides proof-of-concept study of a new versatile approach for AgNPs coating, which may be easily applied to many other types of polymeric or metallic implants through exploiting the adhesive behavior of mussel-inspired coatings., (© 2021 IOP Publishing Ltd.)

Prosthetic rehabilitation of malpositioned anterior dental implants can be challenging. Interdisciplinary treatment planning and precise execution of biologically acceptable prosthetic and surgical protocols are essential to achieve optimal esthetic results and while avoiding and managing esthetic complications. This case study focuses on the restorative aspect. Two sets of custom gold abutments were used prior to and following surgical correction of a pre-existing soft and hard tissue ridge defect surrounding maxillary central incisor implant restorations. A stable and esthetically pleasing result was documented 7 years following delivery of definitive esthetic central incisor implant restorations.

Flap management is one of the key elements for success in periodontal surgeries and bone regeneration for dental implants. The aim of this article is to introduce a releasing incision method for effective flap advancement to obtain tension-free primary closure. The 'upward-motion scissors technique' (UMST) involves the use of surgical scissors handled with an upward motion to create multiple shallow incisions. The use of UMST is demonstrated in an anatomically challenging case requiring bone augmentation. This technique provides a novel approach for flap advancement and may reduce potential complications involved in releasing incisions. The true benefit of UMST needs to be evaluated in future studies.

Objective: Various commercial products are available for guided tissue regeneration (GTR) therapy; however, they do not combine biosafety with the ability to control cell function. The purpose of this study was to evaluate the physicochemical and biological characteristics of the novel bilayer biodegradable poly(lactic-co-glycolic acid) (PLGA) membrane, and to assess whether the bilayer PLGA membrane could be used for periodontal tissue regeneration., Methods: Bilayer biodegradable membrane was fabricated thorough a two-step freezing and lyophilization process using PLGA solution. The characteristics of bilayer membranes were evaluated with respect to surface morphology, stability, mechanical strength, and operability for clinical use. Cell proliferation and osteogenic differentiation were investigated on the each surface of bilayer membrane. Then, these membranes were implanted to the rat calvaria bone defect models and evaluated their capability for tissue regeneration., Results: Biodegradable membranes composed of the solid and porous layer were successfully prepared and the surface morphologies analyzed. Physicochemical analyses revealed that the membranes possessed enough stability and mechanical properties for clinical use. It was also confirmed that the solid layer inhibited cell proliferation and subsequent connective tissue invasion, while the inner layer promoted proliferation and osteogenic differentiation, thus resulting in bone regeneration in vivo., Significance: The layering technology used to fabricate the bilayer polymer membrane could be applied in the developing of other novel biomaterials. The present study demonstrates that the bilayer biodegradable polymer membranes facilitate tissue regeneration in vivo, and therefore represent a prospective biomaterial for GTR therapy., (Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Guided tissue regeneration (GTR) and guided bone regeneration (GBR) biomaterials have been employed in recent years for periodontal procedures. In the present study, widely used dental GTR/GBR biomaterials (grafts: G1, G2, G3 and membranes: M1, M2, M3, M4) were exposed to gamma irradiation at an absorbed dose range of 0-50kGy and the radiolytic intermediates that have been created in the samples upon irradiation were characterized in detail by Electron Spin Resonance (ESR) spectroscopy. We aimed to standardize the measurement conditions for practical applications of gamma radiation sterilization of GTR/GBR biomaterials. We investigated the characteristic features of free radicals in gamma irradiated GTR/GBR biomaterials and examined the stability of the induced radicals at room temperature and accelerated stability conditions with ESR spectroscopy including dose-response curves, microwave power studies, dosimetric features of the biomaterials, variations of the peak heights with temperature, and long term stabilities of the radical species. Long-term stability studies have shown that G1 is quite stable even in accelerated storage conditions. The signal intensities of graft-type GTR/GBR biomaterials stored in normal and stability conditions have decreased very rapidly even only a few days after gamma irradiation sterilization. Thus, those samples indicating relatively low stability features can be very good candidates for the radiosterilization process. The beta-tricalcium phosphate and PLGA containing G1 and M1 respectively have found to be the most gamma stable bone substitute biomaterials and be safely sterilized by gamma radiation. ESR spectroscopy is an appropriate technique in giving important detailed spectroscopic findings in the gamma radiation sterilization studies of GTR/GBR biomaterials., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Clinical outcomes from videoscope assisted minimally invasive surgery (VMIS) at 36 to 58 months are reported., Methods: Fourteen patients having sites with residual probing depth (PD) of at least 5 mm and 2 mm loss of clinical attachment level (CAL) after initial non-surgical therapy were treated with VMIS., Results: At 36 months or greater post-surgery there was a statistically significant improvement (P <0.001) in mean PD and CAL (PD: 3.80 ± 1.18 mm, CAL: 4.16 ± 1.18 mm) in all surgical sites compared with baseline. There was a mean improvement in soft tissue height (0.36 ± 0.64 mm, P = 0.03). In most cases, patients reported no postoperative discomfort., Conclusions: Improvements from VMIS appear to be favorable when compared with previously reported results of periodontal regenerative surgery. All improvements were stable over time. The lack of post-surgical recession after VMIS has not been reported with traditional regenerative surgery.

Objective: Deficient bony ridges often complicate the implant treatment plan. Several treatment modalities are used to regenerate bone, including guided bone regeneration (GBR). The purpose of this study was to summarize the knowledge on different types of membranes available and currently used in GBR procedures in a staged approach or with simultaneous implant placement. The primary role of the membranes is to exclude epithelial and connective tissue cells from the wound area to be regenerated, and to create and maintain the space into which pluripotential and osteogenic cells are free to migrate., Data Sources: A literature search was performed for articles that were published in English on the topic. A selected number of studies were chosen in order to provide a review of the main characteristics, applications, and outcomes of the different types of membranes. Resorbable membranes are made of natural or synthetic polymers like collagen and aliphatic polyesters. Collagens are the most common type used. They have similar collagen composition to the periodontal connective tissue. Other materials available include human, porcine, and bovine pericardium membranes, human amnion and chorion tissue, and human acellular freeze-dried dermal matrix. Nonresorbable membranes used in GBR include dense-polytetrafluoroethylene (d-PTFE), expanded-polytetrafluoroethylene (e-PTFE), titanium mesh, and titanium-reinforced polytetrafluoroethylene., Conclusions: The most common complication of nonresorbable membranes is exposure, which has detrimental effect on the final outcome with both types of membranes. For vertical bone augmentation procedures, the most appropriate membranes are the nonresorbable. For combination defects, both types result in a successful outcome.

Periodontal disease is one of the most common diseases diagnosed in dogs and cats. Guided tissue regeneration (GTR) is a treatment alternative to extraction of strategically important teeth. The barrier membrane used in the GTR procedure is of key importance. The purpose of this case series was to evaluate a liquid polymer gel as a membrane for GTR. The polymer gel ( N-methyl-2-pyrrolidone and poly [DL-lactide]) combined with 8.5% doxycycline hyclate was used in place of a traditional membrane in 4 teeth. The teeth were re-examined 6 months postoperatively for radiographic evaluation. A decrease in probing depth and new alveolar bone formation was seen 6 months postoperatively. Improvement in periodontal disease stage was seen in 2 of the 4 teeth. Larger controlled trials with histopathologic evaluation are indicated to further assess the use of this polymer as a membrane in GTR. However, the clinical outcomes of all 4 treated teeth were considered successful.

Re-establishing compromised periodontium to its original structure, properties and function is demanding, but also challenging, for successful orthodontic treatment. In this study, the periodontal regeneration capability of collagen-hydroxyapatite scaffolds, seeded with bone marrow stem cells, was investigated in a canine labial alveolar bone defect model. Bone marrow stem cells were isolated, expanded and characterized. Porous collagen-hydroxyapatite scaffold and cross-linked collagen-hydroxyapatite scaffold were prepared. Attachment, migration, proliferation and morphology of bone marrow stem cells, co-cultured with porous collagen-hydroxyapatite or cross-linked collagen-hydroxyapatite, were evaluated in vitro. The periodontal regeneration capability of collagen-hydroxyapatite scaffold with or without bone marrow stem cells was tested in six beagle dogs, with each dog carrying one sham-operated site as healthy control, and three labial alveolar bone defects untreated to allow natural healing, treated with bone marrow stem cells - collagen-hydroxyapatite scaffold implant or collagen-hydroxyapatite scaffold implant, respectively. Animals were euthanized at 3 and 6 months (3 animals per group) after implantation and the resected maxillary and mandibular segments were examined using micro-computed tomography scan, H&E staining, Masson's staining and histometric evaluation. Bone marrow stem cells were successfully isolated and demonstrated self-renewal and multi-potency in vitro. The porous collagen-hydroxyapatite and cross-linked collagen-hydroxyapatite had average pore sizes of 415 ± 20 µm and 203 ± 18 µm and porosity of 69 ± 0.5% and 50 ± 0.2%, respectively. The attachment, proliferation and migration of bone marrow stem cells were satisfactory on both porous collagen-hydroxyapatite and cross-linked collagen-hydroxyapatite scaffolds. Implantation of bone marrow stem cells - collagen-hydroxyapatite or collagen-hydroxyapatite scaffold in beagle dogs with experimental periodontal defects resulted in significantly enhanced periodontal regeneration characterized by formation of new bone, periodontal ligament and cementum, compared with the untreated defects, as evidenced by histological and micro-computed tomography examinations. The prepared collagen-hydroxyapatite scaffolds possess favorable bio-compatibility. The bone marrow stem cells - collagen-hydroxyapatite and collagen-hydroxyapatite scaffold - induced periodontal regeneration, with no aberrant events complicating the regenerative process. Further research is necessary to improve the bone marrow stem cells behavior in collagen-hydroxyapatite scaffolds after implantation., (© The Author(s) 2016.)

The aim of this case series was to evaluate the clinical outcome of preformed titanium foil (PTF) to perform guided bone regeneration (GBR) in posterior mandibular atrophies. Thirteen patients (4 male; 9 female; mean age 58.85±10.16 years), with class II division C atrophy, according to Misch, were selected to perform GBR by means of PTF, using a moldable allograft paste as graft material. The devices, made of a 0.2mm thick pure titanium foil, were pre-shaped using stereolithographic models obtained from CT-scan of the patients’ recipient sites. In the second stage, performed at 6.35±2.15 months, 23 cylindrical two-piece implants were placed and the devices removed. At four months, the implants were exposed and submitted to progressive prosthetic load for a span of 4 months. The cases were finalized by means of metal-ceramic cementable restorations. The post finalization follow-up was at 12 months. Survival rate (i.e. SVR) was 100% since no fixtures were lost. At the one-year follow up, the clinical appearance of the soft tissues was optimal and no pathological signs on probing were recorded. The success rate (i.e. SCR) was 82.6% and the average peri-implant bone reabsorption was 0.99±0.59 mm. The results suggest good potentialities of this method for bone volume augmentation in distal mandibular atrophies, allowing to maximize the outcome and simplifying the surgical phase.

Periodontal tissue regeneration is an important application area of biomaterials, given the large proportion of the population affected by periodontal diseases like periodontitis. The aim of this study was the synthesis of a novel porous bioceramic scaffold in the SiO2-CaO-MgO system with specific properties targeted for alveolar bone tissue regeneration using a modification of the traditional foam replica technique. Since bioceramic scaffolds are considered brittle, scaffolds were also coated with gelatin in order to increase their mechanical stability. Gelatin was chosen for its biocompatibility, biodegradability, low-cost, and low immunogenicity. However, gelatin degrades very fast in water solutions. For this reason, two different cross-linking agents were evaluated. Genipin, a non-toxic gardenia extract and the chemical compound 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) in combination with N-hydroxysuccinimide (NHS), which is also considered non-toxic. The results of the investigation indicated that all scaffolds presented an open, interconnected porosity and pores' sizes in the range of 300-600 μm, fast apatite-forming ability, biocompatibility, and suitable mechanical stability., (© The Author(s) 2015.)

Regeneration of dentin tissues in the pulp space of teeth serves the ultimate goal of preserving teeth via endodontic approaches. In recent times, many studies suggested that human dentin scaffolds combined with dental stem cells was a potential strategy for the complete dentin tissue regeneration. In this study, human dental pulp stem cells (DPSCs) were isolated and cultured. Dentin specimens were prepared from human third molars and treated with ethylene diamine tetra-acetic acid and citric acid to remove the smear layer. Then, DPSCs were cultured onto human treated dentin (hTD) and implanted in mouse model for 4, 6 and 8 weeks. The resulting grafts were assessed by hematoxylin and eosin stain and immunohistochemical stains. As a result, DPSCs were supported and induced to regenerate of dentin-like tissues which expressed specific dentin markers such as dentin sialophosphoprotein and dentin matrix protein 1 by combination with hTD in vivo. Furthermore, cells existed in the newly-formed dentin-like tissues also expressed typical human mitochondria antibodies, demonstrated that new tissues originated from human. In conclusion, the obtain results extend hopefully newly-established therapy to apply in endodontics and traumatic dental hard tissues.

Gelatin hydrogels have been designed and prepared for the controlled release of the transforming growth factor (TGF-b1) and the platelet-derived growth factor (PDGF-BB). PRP (Platelet rich plasma) contains many growth factors including the PDGF and TGF-b1. The objective of this study was to evaluate the regeneration of periodontal tissue following the controlled release of growth factors in PRP. For the periodontal ligament cells and osteoblast, PRP of different concentrations was added. The assessment of DNA, mitochondrial activity and ALP activity were measured. To evaluate the TGF-β1 release from PRP incorporated gelatin sponge, amounts of TGF-β1 in each supernatant sample were determined by the ELISA. Transplantation experiments to prepare a bone defect in a rat alveolar bone were an implanted gelatin sponge incorporated with different concentration PRP. In DNA assay and MTT assay, after the addition of PRP to the periodontal ligament cells and osteoblast, the cell count and mitochondrial activity had increased the most in the group with the addition of 5  ×  PRP. In the ALP assay, after the addition of PRP to the periodontal ligament cells, the cell activity had increased the most in the group with the addition of 3  ×  PRP. In the transplantation, the size of the bone regenerated in the defect with 3  ×  PRP incorporated gelatin sponge was larger than that of the other group.

Guided tissue regeneration (GTR) membranes have been used for the management of destructive forms of periodontal disease as a means of aiding regeneration of lost supporting tissues, including the alveolar bone, cementum, gingiva and periodontal ligaments (PDL). Currently available GTR membranes are either non-biodegradable, requiring a second surgery for removal, or biodegradable. The mechanical and biofunctional limitations of currently available membranes result in a limited and unpredictable treatment outcome in terms of periodontal tissue regeneration. In this study, porous membranes of chitosan (CH) were fabricated with or without hydroxyapatite (HA) using the simple technique of freeze gelation (FG) via two different solvents systems, acetic acid (ACa) or ascorbic acid (ASa). The aim was to prepare porous membranes to be used for GTR to improve periodontal regeneration. FG membranes were characterized for ultra-structural morphology, physiochemical properties, water uptake, degradation, mechanical properties, and biocompatibility with mature and progenitor osteogenic cells. Fourier transform infrared (FTIR) spectroscopy confirmed the presence of hydroxyapatite and its interaction with chitosan. μCT analysis showed membranes had 85-77% porosity. Mechanical properties and degradation rate were affected by solvent type and the presence of hydroxyapatite. Culture of human osteosarcoma cells (MG63) and human embryonic stem cell-derived mesenchymal progenitors (hES-MPs) showed that all membranes supported cell proliferation and long term matrix deposition was supported by HA incorporated membranes. These CH and HA composite membranes show their potential use for GTR applications in periodontal lesions and in addition FG membranes could be further tuned to achieve characteristics desirable of a GTR membrane for periodontal regeneration., (Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Objective: The aim of this in vitro study was to investigate the colonization and penetration of specific bacteria on nanosilver-impregnated GTR (guided tissue regeneration) membranes., Methods: Three sets of GTR membranes were used in this study: 1) GTR-C: Plain GTR membrane as a negative control; 2) GTR-NS: GTR membrane impregnated with silver nanoparticles as the test group; 3) GTR-DOX: GTR membrane impregnated with 25% (w/w) doxycycline hydrochloride acting as a positive control. Stress-strain characteristics were calculated to determine the physical properties of the control and impregnated membranes. Qualitative observation of microbial adherence and bacterial penetration through GTR membranes were performed by using four organisms (Streptococcus mutans, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Porphyromonas gingivalis) reported to have strong adherent capabilities to collagen membranes., Results: The mean bacterial adherence scores were significantly greater (p < 0.001) in the GTR-C group when compared to GTR-DOX and GTR-NS groups. GTR-NS showed lower adherence scores than GTR-DOX across all four microorganisms; this difference, however was not statistically significant. The difference in colony forming units (CFUs) was highly significant (p < 0.001), suggesting greater penetration in GTR-C membranes when compared to GTR-NS and GTR-DOX groups. Though the mean CFUs were lower in GTR-DOX than in GTR-NS across all four microorganisms, this difference was statistically significant only for S. mutans and F. nucleatum., Conclusion: The incorporation of silver nanoparticles may be of value when controlling membrane-associated infection. Studies with different nanosilver particle sizes should be conducted to further evaluate the beneficial properties of nanosilver against periodontal pathogens.

Bone tissue engineering applications demand for biomaterials offering a substrate for cell adhesion, migration, and proliferation, while inferring suitable mechanical properties to the construct. In the present study, polyurethane (PU) foams were synthesized to develop a graded porous material-characterized by a dense shell and a porous core-for the treatment of oro-maxillary bone defects. Foam was synthesized via a one-pot reaction starting from a polyisocyanate and a biocompatible polyester diol, using water as a foaming agent. Different foaming conditions were examined, with the aim of creating a dense/porous functional graded material that would perform at the same time as an osteoconductive scaffold for bone defect regeneration and as a membrane-barrier to gingival tissue ingrowth. The obtained PU was characterized in terms of morphological and mechanical properties. Biocompatibility assessment was performed in combination with bone-marrow-derived human mesenchymal stromal cells (hBMSCs). Our findings confirm that the material is potentially suitable for guided bone regeneration applications., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Aim: The local delivery of growth factors via gene therapy has gained tremendous awareness in recent years due to their sustained growth factor delivery to target tissues. The aim of this study was to fabricate and investigate a scaffold able to release growth factors via gene therapy for the repair of periodontal tissues., Materials and Methods: Novel mesoporous bioglass (MBG)/silk fibrin scaffold combined with BMP7 and/or PDGF-B adenovirus was fabricated and tested in vitro for cell migration, proliferation and differentiation. Furthermore, acute-type buccal dehiscence periodontal defects (mesiodistal width × depth: 5 × 5 mm) were created on the buccal portion of the maxillary premolars in five normal male beagle dogs (12 months old, 15.0 ± 2.0 kg) and histologically examined for periodontal regeneration following implantation of the following five groups: (1) no scaffold, (2) MBG/silk scaffold alone, (3) scaffold + adPDGF-B, (4) scaffold + adBMP7, (5) scaffold + adPDGF-b + adBMP7., Results: In vitro findings demonstrated that adPDGF-B was able to rapidly recruit periodontal ligament (PDL) cells over sixfold more effectively than adBMP7, whereas adBMP7 was more able to induce osteoblast differentiation of PDL cells. In vivo findings demonstrate that scaffolds loaded with adPDGF-B were able to partially regenerate the periodontal ligament while adBMP7 scaffolds primarily improved new bone formation. The combination of both adPDGF-B and adBMP7 synergistically promoted periodontal regeneration by allowing up to two times greater regeneration of the periodontal ligament, alveolar bone and cementum when compared to each adenovirus used alone., Conclusions: Although both PDGF-B and BMP7 are individually capable of promoting periodontal regeneration to some degree, their combination synergistically promotes wound healing in acute-type buccal dehiscence periodontal defects when delivered simultaneously. This study demonstrates the promise for successful delivery of low-cost, effective growth factor delivery via gene therapy for the treatment of periodontal defects., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

To engineer constructs of the periodontal ligament (PDL), human PDL cells were incorporated into a matrix of hyaluronan, gelatin, and type I collagen (COLI) in sample holders (13×1 mm) of six-well Biopress culture plates. The loading dynamics of the PDL were mimicked by applying a cyclic compressive strain of 33.4 kPa (340.6 gm/cm(2)) to the constructs for 1.0 s every 60 s, for 6, 12, and 24 h in a Flexercell FX-4000C Strain Unit. Compression significantly increased the number of nonviable cells and increased the expression of several apoptosis-related genes, including initiator and executioner caspases. Of the 15 extracellular matrix genes screened, most were upregulated at some point after 6-12 h deformation, but all were downregulated at 24 h, except for MMPs1-3 and CTGF. In culture supernatants, matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinases-1 (TIMP-1) protein levels were upregulated at 24 h; receptor activator of nuclear kappa factor B (RANKL), osteoprotegerin (OPG) and fibroblast growth factor-2 (FGF-2) were unchanged; and connective tissue growth factor (CTGF) not detected. The low modulus of elasticity of the constructs was a disadvantage-future mechanobiology studies and tissue engineering applications will require constructs with much higher stiffness. Since the major structural protein of the PDL is COLI, a more rational approach would be to permeabilize preformed COLI scaffolds with PDL-populated matrices.

Background: Soft tissue regeneration and remodeling is fundamental in periodontal surgery, thus we investigated the angiogenic response elicited in the subcutaneous tissue of rats by a proprietary, polyethylene glycol hydrogel formulation (PEG) alone or conjugated with specific amelogenins (EMD) or nanobioglass particles (NBG)., Methods: Discs with three different formulations (PEG, PEG-EMD, and PEG-NBG) were inserted into four unconnected subcutaneous pouches, produced on the back of Sprague-Dawley rats (n=56, divided into three groups), and used for blood flow evaluation by Laser Doppler analysis at 1, 2, 4, 8, and 16 weeks or for histological and immunohistochemical analysis at 1, 2, 4, 8, and 16 weeks., Results: All formulations showed tissue integration, absence of inflammatory reaction (as revealed by myeloperoxidase staining), and increased vascularization (by counting microvascular density following CD31 staining). Laser Doppler analysis revealed a statistically significant increase in blood flow after 1 week for PEG-EMD and after 2 weeks for PEG-NBG. The angiogenic response was significantly increased at 1, 2, and 8 weeks for PEG-EMD, but only at 4 weeks for PEG-NBG., Conclusions: The studied biomaterials revealed equal biocompatibility and tissue integration properties. PEG-EMD showed the most pronounced and consistent angiogenic response in the early phases of wound healing, while the PEG-NBG formulation provided a slower and delayed, but relevant, response.

Aim: The present work describes a horizontal ridge augmentation in which a titanium mesh was preshaped by adapting it to a stereolithographic model of the patient's jaw that was fabricated from CT scans., Background: Guided bone regeneration (GBR) involves covering the augmentation site with a long-lasting barrier to protect it from the invasion of surrounding soft tissues. Among barriers, titanium meshes may provide a successful outcome, but the intraoperatory time needed to shape them is a disadvantage., Case Description: The 54-year-old patient, missing the right mandibular second bicuspid, first molar, and second molar, had her atrophic ridge augmented with a 30:70 mixture of autogenous bone and equine, enzyme-deantigenic collagen-preserved bone substitute. Two conical implants were inserted concomitantly in the second bicuspid and first molar positions, and the site was protected with the preshaped mesh. Four months later, the titanium mesh was retrieved, a bone sample was collected, and histological and histomorphometric analyses were performed. Provisional and definitive prostheses were then delivered, and follow-up controls were performed for up to 24 months., Conclusion: Preshaping the mesh on a model of the patient's mandible shortened the surgical time and enabled faster mesh placement. Two years after surgery, the implants were perfectly functional, and the bone width was stable over time as shown by radiographic controls. Histological analysis of the bone sample showed the heterologous biomaterial to be biocompatible and undergoing advanced remodeling and replacement with newly formed bone., Clinical Significance: Preshaping a titanium mesh over a stereolithographic model of the patient's jaw allowed for a significant reduction of the intraoperative time and may be therefore, advisable in routine practice.

Sixty percent of implant-supported dental prostheses require bone grafting to enhance bone quantity and quality prior to implant placement. We have developed a metallic magnesium particle/PLGA composite scaffold to overcome the limitations of currently used dental bone grafting materials. This is the first report of porous metallic magnesium/PLGA scaffolds synthesized using a solvent casting, salt leaching method. We found that incorporation of varying amounts of magnesium into the PLGA scaffolds increased the compressive strength and modulus, as well as provided a porous structure suitable for cell infiltration, as measured by mercury intrusion porosimetry. Additionally, combining basic-degrading magnesium with acidic-degrading PLGA led to an overall pH buffering effect and long-term release of magnesium over the course of a 10-week degradation assay, as measured with inductively coupled plasma-atomic emission spectroscopy. Using an indirect proliferation assay adapted from ISO 10993:5, it was found that extracts of medium from degrading magnesium/PLGA scaffolds increased bone marrow stromal cell proliferation in vitro, a phenomenon observed by other groups investigating magnesium's impact on cells. Finally, magnesium/PLGA scaffold biocompatibility was assessed in a canine socket preservation model. Micro-computed tomography and histological analysis showed the magnesium/PLGA scaffolds to be safer and more effective at preserving bone height than empty controls. Three-dimensional magnesium/PLGA composite scaffolds show promise for dental socket preservation and also, potentially, orthopedic bone regeneration. These scaffolds could decrease inflammation observed with clinically used PLGA devices, as well as enhance osteogenesis, as observed with previously studied magnesium devices., (Copyright © 2014. Published by Elsevier Ltd.)

Periodontitis is a chronic inflammatory disorder affecting nearly 50% of adults in the United States. If left untreated, it can lead to the destruction of both soft and mineralized tissues that constitute the periodontium. Clinical management, including but not limited to flap debridement and/or curettage, as well as regenerative-based strategies with periodontal membranes associated or not with grafting materials, has been used with distinct levels of success. Unquestionably, no single implantable biomaterial can consistently guide the coordinated growth and development of multiple tissue types, especially in very large periodontal defects. With the global aging population, it is extremely important to find novel biomaterials, particularly bioactive membranes and/or scaffolds, for guided tissue (GTR) and bone regeneration (GBR) to aid in the reestablishment of the health and function of distinct periodontal tissues. This chapter offers an update on the evolution of biomaterials (i.e. membranes and bioactive scaffolds) as well as material-based strategies applied in periodontal regeneration. The authors start by providing a brief summary of the histological characteristics and functions of the periodontium and its main pathological condition, namely periodontitis. Next, a review of commercially available GTR/GBR membranes is given, followed by a critical appraisal of the most recent advances in the development of bioactive materials that enhance the chance for clinical success of periodontal tissue regeneration., (© 2015 S. Karger AG, Basel.)

Objectives: Evaluate the antibacterial properties of three commercial collagen membranes for guided bone regeneration (GBR)., Method and Materials: BioGide®, OsseoGuard®, and CopiOs® membranes were tested for antibacterial properties against Streptococcus sanguinis, Staphylococcus aureus, and Staphylococcus epidermidis using a direct contact test (DCT). Samples of each membrane, sized 5 × 2 mm, were fixed to the side wall of 6 wells in a 96-well microtiter plate. Bacterial suspension was placed on each sample. The plate was incubated at 37°C for 1 hour to allow suspension fluid evaporation. Fresh medium was added to each well and the plate was mixed. Non-contaminated membrane samples served as negative control. Bacterial growth was monitored spectrophotometrically at 650 nm for 24 hours. ANOVA and Tukey's comparison tests were used for the statistical analysis., Results: The presence of the membrane samples did not disrupt bacterial growth. However, the presence of OsseoGuard membrane accelerated bacterial growth rate of S sanguinis and S epidermidis as compared to the other two membranes and control samples (P < .001), and of S aureus as compared to the control alone (P < .001)., Conclusions: The tested collagen membranes have no antibacterial properties. However, OsseoGuard presents a significant bacterial growth enhancement effect with possible significant clinical implications on the success of regenerative procedures around teeth and implants.

Physiologic bioengineering of the oral, dental, and craniofacial complex requires optimized geometric organizations of fibrous connective tissues. A computer-designed, fiber-guiding scaffold has been developed to promote tooth-supporting periodontal tissue regeneration and functional restoration despite limited printing resolution for the manufacture of submicron-scaled features. Here, we demonstrate the use of directional freeze-casting techniques to control pore directional angulations and create mimicked topographies to alveolar crest, horizontal, oblique, and apical fibers of natural periodontal ligaments. For the differing anatomic positions, the gelatin displayed varying patterns of ice growth, determined via internal pore architectures. Regardless of the freezing coordinates, the longitudinal pore arrangements resulted in submicron-scaled diameters (~50 µm), along with corresponding high biomaterial porosity (~90%). Furthermore, the horizontal + coronal ([Formula: see text]) freezing orientation facilitated the creation of similar structures to major fibers in the periodontal ligament interface. This periodontal tissue-mimicking microenvironment is a potential tissue platform for the generation of naturally oriented ligamentous tissues consistent with periodontal ligament neogenesis., (© International & American Associations for Dental Research.)

The periodontal ligament is the key tissue facilitating periodontal regeneration. This study aimed to fabricate decellularized human periodontal ligament cell sheets for subsequent periodontal tissue engineering applications. The decellularization protocol involved the transfer of intact human periodontal ligament cell sheets onto melt electrospun polycaprolactone membranes and subsequent bi-directional perfusion with NH4OH/Triton X-100 and DNase solutions. The protocol was shown to remove 92% of DNA content. The structural integrity of the decellularized cell sheets was confirmed by a collagen quantification assay, immunostaining of human collagen type I and fibronectin, and scanning electron microscopy. ELISA was used to demonstrate the presence of residual basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and hepatocyte growth factor (HGF) in the decellularized cell sheet constructs. The decellularized cell sheets were shown to have the ability to support recellularization by allogenic human periodontal ligament cells. This study describes the fabrication of decellularized periodontal ligament cell sheets that retain an intact extracellular matrix and resident growth factors and can support repopulation by allogenic cells. The decellularized hPDL cell sheet concept has the potential to be utilized in future "off-the-shelf" periodontal tissue engineering strategies., (© International & American Associations for Dental Research.)

Periodontitis is an inflammatory disease that causes loss of the tooth-supporting apparatus, including periodontal ligament, cementum, and alveolar bone. A broad range of treatment options is currently available to restore the structure and function of the periodontal tissues. A regenerative approach, among others, is now considered the most promising paradigm for this purpose, harnessing the unique properties of stem cells. How to make full use of the body's innate regenerative capacity is thus a key issue. While stem cells and bioactive factors are essential components in the regenerative processes, matrices play pivotal roles in recapitulating stem cell functions and potentiating therapeutic actions of bioactive molecules. Moreover, the positions of appropriate bioactive matrices relative to the injury site may stimulate the innate regenerative stem cell populations, removing the need to deliver cells that have been manipulated outside of the body. In this topical review, we update views on advanced designs of biomatrices-including mimicking of the native extracellular matrix, providing mechanical stimulation, activating cell-driven matrices, and delivering bioactive factors in a controllable manner-which are ultimately useful for the regenerative therapy of periodontal tissues., (© International & American Associations for Dental Research.)

Medium perfusion has been shown to enhance cell proliferation and matrix protein production. In more recent work, under perfusion, a degradable/polar/hydrophobic/ionic polyurethane (D-PHI) scaffold was shown to enhance growth and production of collagen by human gingival fibroblasts (HGFs). However, the nature of the HGFs cultured in the perfused D-PHI scaffolds, and the mechanisms by which medium perfusion activates these cells to facilitate proliferation and collagen production are not defined. The current study sought to investigate HGF interaction within the D-PHI scaffolds under perfusion by examining the production and the spatial distribution of α-smooth muscle actin (α-SMA) and type I collagen (Col I), the secretion of transforming growth factor (TGF)-β1 and basic fibroblast growth factor (FGF-2) in the conditioned medium, with a goal of defining the mechanistic pathways affecting the production of these markers in the dynamic culture. It was found that the perfused D-PHI scaffold shifted the HGF phenotype from myofibroblast-like (upregulation of α-SMA) to fibroblast-like (downregulation of α-SMA) over the course of 28 days. Both TGF-β1 and FGF-2 were significantly greater in the dynamic vs. static culture at day 1. Although TGF-β1 has been often reported to increase α-SMA and collagen expression, the D-PHI material and significant high level of FGF-2 at day 1 of dynamic culture appear to play a role in regulating α-SMA production while allowing HGFs to increase Col I production. β1-integrin production was increased and focal adhesion kinase (FAK) were activated 2 h after HGFs were exposed to medium perfusion, which may have in part promoted cell growth, α-SMA and Col I production in the early dynamic culture. Consequently, the D-PHI material and medium perfusion has modulated fibroblast phenotype, and enhanced cell growth and Col I production through the coordinated actions of TGF-β1, FGF-2, β1-integrin and FAK., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

For a successful clinical outcome, periodontal regeneration requires the coordinated response of multiple soft and hard tissues (periodontal ligament, gingiva, cementum, and bone) during the wound-healing process. Tissue-engineered constructs for regeneration of the periodontium must be of a complex 3-dimensional shape and adequate size and demonstrate biomechanical stability over time. A critical requirement is the ability to promote the formation of functional periodontal attachment between regenerated alveolar bone, and newly formed cementum on the root surface. This review outlines the current advances in multiphasic scaffold fabrication and how these scaffolds can be combined with cell- and growth factor-based approaches to form tissue-engineered constructs capable of recapitulating the complex temporal and spatial wound-healing events that will lead to predictable periodontal regeneration. This can be achieved through a variety of approaches, with promising strategies characterized by the use of scaffolds that can deliver and stabilize cells capable of cementogenesis onto the root surface, provide biomechanical cues that encourage perpendicular alignment of periodontal fibers to the root surface, and provide osteogenic cues and appropriate space to facilitate bone regeneration. Progress on the development of multiphasic constructs for periodontal tissue engineering is in the early stages of development, and these constructs need to be tested in large animal models and, ultimately, human clinical trials., (© International & American Associations for Dental Research.)

The development of bone augmentation procedures has allowed placement of dental implants into jaw bone areas lacking an amount of bone sufficient for standard implant placement. Thus, the indications for implants have broadened to include jaw regions with bone defects and those with a bone anatomy that is unfavorable for implant anchorage. Of the different techniques, the best documented and the most widely used method to augment bone in localized alveolar defects is guided bone regeneration. A large body of evidence has demonstrated the successful use of guided bone regeneration to regenerate missing bone at implant sites with insufficient bone volume and the long-term success of implants placed simultaneously with, or after, guided bone regeneration. However, the influence of guided bone regeneration on implant survival and success rates, and the long-term stability of the augmented bone, remain unknown. Many of the materials and techniques currently available for bone regeneration of alveolar ridge defects were developed many years ago. Recently, various new materials and techniques have been introduced. Many of them have, however, not been sufficiently documented in clinical studies. The aim of this review was to present the scientific basis of guided bone regeneration and the accepted clinical procedures. A classification of bone defects has been presented, aiming at simplifying the decision-making process regarding the choice of strategy for bone augmentation. Finally, an outlook into actual research and the possible future options related to bone augmentation has been provided., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Dental caries is one of the most prevalent chronic diseases in the United States, affecting 92% of adults aged 20-64 years. Scaffold-based tissue engineering represents a promising strategy to replace damaged dental structures and restore their biological functions. Current single-component scaffolding materials used for dental tissue regeneration, however, cannot provide the proper microenvironment for dental stem/progenitor cell adhesion, proliferation, and differentiation; new biomimetic hybrid scaffolds are needed to promote better dental tissue formation. In this work, we developed a biomimetic approach to prepare three-dimensional (3D) nanofibrous gelatin/magnesium phosphate (NF-gelatin/MgP) hybrid scaffolds. These scaffolds not only mimic the nanostructured architecture and the chemical composition of natural dentin matrices but also constantly present favorable chemical signals (Mg ions) to dental pulp stem cells (DPSCs), thus providing a desirable microenvironment to facilitate DPSC proliferation, differentiation, and biomineralization. Synthesized hybrid NF-gelatin/MgP possesses natural extracellular matrix (ECM)-like architecture, high porosity, high pore interconnectivity, well-defined pore size, and controlled Mg ion release from the scaffold. Adding MgP into NF-gelatin also increased the mechanical strength of the hybrid scaffold. The sustained release of Mg ions from the NF-gelatin/MgP (MgP=10% wt/wt) scaffold significantly enhanced the proliferation, differentiation, and biomineralization of human DPSCs in vitro. The alkaline phosphatase (ALP) activity and the gene expressions for odontogenic differentiation (collagen I [Col I], ALP, osteocalcin [OCN], dentin sialophosphoprotein [DSPP], and dentin matrix protein 1 [DMP1]) were all significantly higher (p<0.05) in the NF-gelatin/MgP group than in the NF-gelatin group. Those results were further confirmed by hematoxylin and eosin (H&E) and von Kossa staining, as shown by greater ECM secretion and mineral deposition in the hybrid scaffold. Consistent with the in vitro study, the DPSCs/NF-gelatin/MgP constructs produced greater ECM deposition, hard tissue formation, and expression of marker proteins (DSPP, DMP1, Col I) for odontogenic differentiation than did the DPSCs/NF-gelatin after 5 weeks of ectopic implantation in rude mice. The controlled release of metallic ions from biomimetic nanostructured hybrid scaffolds, therefore, is a promising approach to enhancing the biological capability of the scaffolds for dental tissue regeneration.

Human and canine periodontium are often affected by an inflammatory pathology called periodontitis, which is associated with severe damages across tissues, namely, in the periodontal ligament, cementum, and alveolar bone. However, the therapies used in the routine dental practice, often consisting in a combination of different techniques, do not allow to fully restore the functionality of the periodontium. Tissue Engineering (TE) appears as a valuable alternative approach to regenerate periodontal defects, but for this purpose, it is essential to develop supportive biomaterial and stem cell sourcing/culturing methodologies that address the complexity of the various tissues affected by this condition. The main aim of this work was to study the in vitro functionality of a newly developed double-layer scaffold for periodontal TE. The scaffold design was based on a combination of a three-dimensional (3D) fiber mesh functionalized with silanol groups and a membrane, both made of a blend of starch and poly-ɛ-(caprolactone). Adipose-derived stem cells (canine adipose stem cells [cASCs]) were seeded and cultured onto such scaffolds, and the obtained constructs were evaluated in terms of cellular morphology, metabolic activity, and proliferation. The osteogenic potential of the fiber mesh layer functionalized with silanol groups was further assessed concerning the osteogenic differentiation of the seeded and cultured ASCs. The obtained results showed that the proposed double-layer scaffold supports the proliferation and selectively promotes the osteogenic differentiation of cASCs seeded onto the functionalized mesh. These findings suggest that the 3D structure and asymmetric composition of the scaffold in combination with stem cells may provide the basis for developing alternative therapies to treat periodontal defects more efficiently.

Implant peri-apical lesion (IPL) is a periapical lesion, usually asymptomatic, in which the coronal portion of the implant achieves a normal bone to implant interface. A case of IPL following immediate implant placement and treated with guided bone regeneration (GBR) principles is described. Five-year clinical and radiographic follow-up with cone-beam assessment showed complete healing of the bone. GBR principles applied to IPL could completely solve the lesion.

With the advance of dental implant technology and the consequential increase in its success rate, the implant has become a highly predictable treatment method. Despite this, related complications are on the rise, with peri-implant mucositis and peri-implantitis being the most commonly observed. As in the case of conventional periodontitis, many patients experience peri-implant mucositis and peri-implantitis. In this case presentation, extensive bone loss occurred around the implant due to peri-implantitis, and the infection was first treated by applying chlorhexidine-soaked gauze and topical antibiotics. Then the guided bone regeneration procedure was performed using a bovine bone material and a collagen membrane, which resulted in the recovery of the lesion. With follow-ups of the healing process for 30 months, a successful outcome was observed that is reported herein.

Objective: To systematically analyze the regenerative effect of the available biomaterials either alone or in various combinations for the treatment of periodontal intrabony defects as evaluated in preclinical histologic studies., Data Sources: A protocol covered all aspects of the systematic review methodology. A literature search was performed in Medline, including hand searching. Combinations of searching terms and several criteria were applied for study identification, selection, and inclusion. The preliminary outcome variable was periodontal regeneration after reconstructive surgery obtained with the various regenerative materials, as demonstrated through histologic/ histomorphometric analysis. New periodontal ligament, new cementum, and new bone formation as a linear measurement in mm or as a percentage of the instrumented root length were recorded. Data were extracted based on the general characteristics, study characteristics, methodologic characteristics, and conclusions. Study selection was limited to preclinical studies involving histologic analysis, evaluating the use of potential regenerative materials (ie, barrier membranes, grafting materials, or growth factors/proteins) for the treatment of periodontal intrabony defects. Any type of biomaterial alone or in various combinations was considered. All studies reporting histologic outcome measures with a healing period of at least 6 weeks were included. A meta-analysis was not possible due to the heterogeneity of the data., Conclusion: Flap surgery in conjunction with most of the evaluated biomaterials used either alone or in various combinations has been shown to promote periodontal regeneration to a greater extent than control therapy (flap surgery without biomaterials). Among the used biomaterials, autografts revealed the most favorable outcomes, whereas the use of most biologic factors showed inferior results compared to flap surgery.

Objectives: The management of white-spot lesions remains a challenge, especially during and after fixed orthodontic treatment. The aim of this in vitro study was to evaluate the efficacy of the newly introduced self-assembling peptide P11-4 (Curodont™) for regenerating demineralized tooth tissue on smooth surfaces. Another aim was to evaluate whether the DIAGNOdent (DD) and VistaProof (VP) fluorescence systems are suitable for differentiating between demineralized and remineralized enamel., Materials and Methods: A total of 40 sound samples (buccal surfaces) of extracted human posterior teeth were artificially demineralized. The samples were examined visually as well as via DD and VP. Curodont was applied to 30 samples which were then stored in a remineralizing agent (test group). In control group 1, Curodont was applied to 5 samples which were then stored in water. Control group 2 consisted of 5 samples stored in the remineralizing agent only. Sample surfaces were examined visually and by means of DD and VP after 1 week (t1), 8 weeks (t2), and 12 weeks (t3). All fluorescence measurements were taken twice. Sample surfaces were viewed using a scanning electron microscope (SEM). Statistical analysis was conducted using the IBM SPSS® Statistics and MedCalc® programs. The fluorescence measurements' reproducibility was calculated using the intraclass correlation coefficient (ICC). A χ(2) test was applied to detect any significant differences between the fluorescence measurements of the test and control groups at each examination. Receiver operating characteristic (ROC) curves of DD and VP were constructed and areas under the ROC curve (AUC) were compared (α = 0.05) between the two fluorescence devices., Results: Reproducibility of DD was moderate at t3, while the ICC values were high for all other measurements. Significant differences between the fluorescence measurements at t2 and t3 between the test and control groups (p < 0.001 for DD and VP, respectively) were observed. The performance (AUC) of DD was significantly higher than VP (visual inspection: p = 0.017; SEM: p = 0.030). At t3, all test-group samples displayed a shinier surface than the surface after demineralization. The SEM images of 28 test-group samples exhibited extensive signs of remineralized enamel., Conclusion: Based on visual inspection, Curodont proved to be efficacious in all samples. The SEM images revealed large areas of remineralized enamel surface in 93 % of the samples. Both fluorescence systems enabled the detection of differences between the measurements of the test and control groups after 8 and 12 weeks.

Background: In guided tissue regenerative surgery, membrane perforations may serve as a mechanism for the passage of cells and biologic mediators from the periosteum and overlying gingival connective tissue into the periodontal defects. To test this assumption, this study was designed to evaluate levels of bone morphogenetic protein-2 (BMP-2) in gingival crevicular fluid (GCF) during the early stages of healing for sites treated with modified perforated membranes (MPMs) as compared with occlusive membranes (OMs)., Methods: Fifteen non-smoking patients with severe chronic periodontitis participated in this prospective, randomized and single-blinded clinical trial. Each patient contributed two interproximal contralateral defects that were randomly assigned to either an experimental modified perforated membrane group (15 sites) or a control occlusive membrane group (15 sites). Plaque index, gingival index, probing depth(PD), clinical attachment level (CAL) and the relative intrabony depth of the defect (rIBD) were measured at baseline and reassessed at three, six and nine months after therapy. Gingival crevicular fluid samples were collected on day 1 and 3, 7, 14, 21, and 30 days after therapy., Results: The MPM-treated group showed a statistically significant improvement in PD reduction and clinical attachment gain compared to the OM control group. Similarly, rIBD was significantly reduced in MPM-treated sites as compared with those of the OM group. BMP-2 concentrations peaked in the MPM samples obtained during the early postoperative period (days 1, 3 and 7) with a statistically significant difference compared with OM-treated groups. BMP-2 levels decreased sharply in the samples obtained at days 14, 21 and 30 with non-significant higher levels in MPM samples as compared with those of OM sites., Conclusion: Within the limits of the present study, one can conclude that MPM coverage of periodontal defects is associated with a significant initial increase in GCF levels of BMP-2, a factor that could improve the clinical outcomes of guided tissue regenerative surgery.

Aim: This study investigated the ability of an osteoconductive biphasic scaffold to simultaneously regenerate alveolar bone, periodontal ligament and cementum., Materials and Methods: A biphasic scaffold was built by attaching a fused deposition modelled bone compartment to a melt electrospun periodontal compartment. The bone compartment was coated with a calcium phosphate (CaP) layer for increasing osteoconductivity, seeded with osteoblasts and cultured in vitro for 6 weeks. The resulting constructs were then complemented with the placement of PDL cell sheets on the periodontal compartment, attached to a dentin block and subcutaneously implanted into athymic rats for 8 weeks. Scanning electron microscopy, X-ray diffraction, alkaline phosphatase and DNA content quantification, confocal laser microscopy, micro computerized tomography and histological analysis were employed to evaluate the scaffold's performance., Results: The in vitro study showed that alkaline phosphatase activity was significantly increased in the CaP-coated samples and they also displayed enhanced mineralization. In the in vivo study, significantly more bone formation was observed in the coated scaffolds. Histological analysis revealed that the large pore size of the periodontal compartment permitted vascularization of the cell sheets, and periodontal attachment was achieved at the dentin interface., Conclusions: This work demonstrates that the combination of cell sheet technology together with an osteoconductive biphasic scaffold could be utilized to address the limitations of current periodontal regeneration techniques., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Alveolar bone loss and bone defects are the commonly encountered periodontal problems. Large defects do not heal spontaneously and thus require surgical interventions with bone substitutes. Bone grafts have the disadvantages of eliciting an immunologic response with subsequent graft rejection. The success rate of Guided Tissue Regeneration (GTR) is variable because of high susceptibility to infection. Thus emerged the important role of synthetic biomaterials and hence for this purpose we developed a nanocomposite scaffold, using alpha- and beta-chitin hydrogel with bioactive glass ceramic nanoparticles (nBGC) and silver nanoparticles (nAg) by lyophilization technique (aalpha and beta-chitin hydrogel/nBGC/nAg nanocomposite scaffold). The prepared nanoparticles and nanocomposite scaffolds were characterized. In addition, the porosity, swelling, mechanical properties, antibacterial activity, in vitro degradation and biomineralization, cell viability, cell attachment and cell proliferation ability of the prepared composite scaffolds were also evaluated. The results showed that alpha- and beta-chitin/nBGC/nAg composite scaffolds were porous and have the capacity to absorb fluids and swell. The composite scaffolds also showed enhanced antibacterial activity, bioactivity and controlled degradation in comparison to the control scaffolds. Cell viability studies proved the non-toxic nature of the nanocomposite scaffolds. Cell attachment and cell proliferation studies revealed the attachment and spreading nature of cells. All these studies revealed that, these antibacterial nanocomposite scaffolds could be a promising approach for the management of periodontal defects.

The aim of this research was to determine the bone formation capacity in fenestration defects associated with dental implants using absorbable and non-absorbable membranes. Six dogs were used in the study. In both tibias of each animal 3 implants were installed, and around these 5 mm circular defects were created. The defects were covered with absorbable membranes (experimental group 1), non-absorbable membranes (experimental group 2), and the third defect was not covered (control group). At 3 and 8 weeks post-surgery, the animals were euthanized and the membranes with the bone tissue around the implants were processed for histological analysis. The statistical analysis was conducted with Tukey's test, considering statistical significance when p<0.1. Adequate bone repair was observed in the membrane-covered defects. At 3 weeks, organization of the tissue, bone formation from the periphery of the defect and the absence of inflammatory infiltrate were observed in both experimental groups, but the defect covered with absorbable membrane presented statistically greater bone formation. At 8 weeks, both membrane-covered defects showed adequate bone formation without significant differences, although they did in fact present differences with the control defect in both periods (p>0.1). In the defects without membrane, continuous connective tissue invasions and bone repair deficiency were observed. There were no significant differences in the characteristics and volume of the neoformed bone in the defects around the implants covered by the different membranes, whereas the control defects produced significantly less bone. The use of biological membranes contributes to bone formation in three-wall defects.

Background: The aim of the present study is to perform a systematic review of the literature on the use of titanium grids for implant surgery before and simultaneously with implant placement and to assess the success rate of the procedure, as well as survival and success rates of implants placed in the regenerated areas., Methods: Medline was used to identify studies in English published from 1996 to 2011. An additional hand search was performed of the relevant journals and of the bibliographies of the papers identified. Articles retrieved by two independent authors were screened using specific inclusion criteria: randomized controlled trials (RCTs), controlled clinical trials, and prospective clinical studies regarding vertical and/or horizontal regeneration of the alveolar ridge using titanium grids, in association or not with biomaterials, before and simultaneously with implant placement., Results: Six articles were selected, including a total of 79 patients, 87 titanium grids, and 141 implants. Twenty-four implants were placed simultaneously with titanium grids, and 117 implants were inserted after a period of 4 to 9 months. Titanium grids in combination with autogenous bone were used in 43 cases, 25 in combination with a mixture of autogenous bone and bone substitutes, 14 in association with bone substitutes, five using only titanium grids. The overall success rate of the regenerative procedures was 98.86%; the overall survival and success rates of implants were 100% and 93.2%, respectively., Conclusions: The main limit of the present systematic review is the scarcity of papers with an adequate and consistent methodology regarding the data collection and analysis and the lack of RCTs and large well-designed long-term trials. Survival and success rates of implants placed in the areas treated with titanium grids were comparable to those of implants placed in native, non-regenerated bone and of implants placed in bone regenerated with resorbable and non-resorbable membranes.

Guided tissue regeneration (GTR) with bioabsorbable collagen membranes (CM) is commonly used for the treatment of periodontal defects. The objective of this systematic review of randomized clinical trials was to assess the clinical efficacy of GTR procedures with CM, with or without bone substitutes, in periodontal infrabony defects compared with that of open flap debridement (OFD) alone. Primary outcomes were tooth loss and gain in clinical attachment level (CAL). Screening of records, data extraction, and risk-of-bias assessments were performed by two reviewers. Weighted mean differences were estimated by random effects meta-analysis. We included 21 reports on 17 trials. Risk of bias was generally high. No data were available for the primary outcome tooth loss. The summary treatment effect for change in CAL for GTR with CM compared with OFD was 1.58 mm (95% CI, 1.27 to 1.88). Despite large between-trial heterogeneity (I2 = 75%, p < .001), all trials favored GTR over OFD. No differences in treatment effects were detected between trials of GTR with CM alone and trials of GTR with CM in combination with bone substitutes (p for interaction, .31). GTR with CM, with or without substitutes, may result in improved clinical outcomes compared with those achieved with OFD alone. Our findings support GTR with CM for the treatment of infrabony periodontal defects.

Purpose: To present a new technique for the rehabilitation of the severely atrophied mandible that avoids the need for advanced surgical reconstruction., Materials and Methods: Severe resorption in the posterior mandible was treated following a conservative approach. A novel drilling technique and vertical implant-guided bone regeneration were performed to insert extra-short implants for maximum use of the bone above the mandibular canal. A progressive loading protocol was followed for the prosthetic rehabilitation with screw-retained prostheses. During the follow-up period, surgical complications, prosthetic failures, marginal bone loss, and implant survival were monitored., Results: The described conservative approach was effective in patients with residual bone height above the mandibular canal that was often less than 6 mm. No signs of sensory disturbances or nerve injury were detected during the observation period. One hundred fourteen extra-short implants were inserted in 72 patients, with a mean follow-up period of 26 months after implant insertion. The implant survival rate was 98.2% (two implants failed). Proximal bone loss was limited to 1 mm, and detailed analysis of factors influencing bone loss indicated that the increase in implant diameter was associated with a tendency toward decreased bone loss. Prosthetic complications (eg, fracture or screw loosening) were not observed in this study., Conclusions: This minimally invasive approach contributed to successful oral rehabilitation of patients with severely atrophied posterior mandibles. The development of conservative approaches will decrease the risk of surgical morbidity, save money and time, and decrease the complexity of surgery.

The study was aimed to provide insights into the effect of nano-hydroxyapatite (nHA) suspension on cell proliferation and cycle of human periodontal ligament cells, offering the evidence for nHA being used in periodontal therapy. Human periodontal ligament cells (HPDLCs) were cultured in different concentrations of nano-hydroxyapatite/sodium carboxymethyl cellulose (nHA-CMCNa) suspension in vitro. After that, cell proliferation ability was examined by MTT [3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and flow cytometry. MTT assay demonstrated that the Relative Proliferation Rate (RPR) of 0.5% nHA-CMCNa group was significantly higher than other groups (p <0.05), which means that nHA-CMCNa might increase cell proliferation ability. Flow cytometry showed that cells in G1 phase decreased, whilst cells in S phase increased after cultured in nHA-CMCNa suspension for 48 h. The result suggested that part of cells finished G1 phase in advance and get into S phase earlier, which speed up the cell proliferation, nHA-CMCNa suspension had great effect on cell proliferation. The high concentration of nHA-CMCNa could shorten the time in G1 phase, impel part of cells into S phase, and accelerate proliferation rate of HPDLCs.

Purpose: To compare bone augmentation on pure titanium-machined surfaces and surfaces that have been modified by microarc oxidation (MAO) using titanium caps., Materials and Methods: Twenty caps were manufactured from rods of commercially pure titanium. The control group (CG) consisted of 10 titanium caps with machined inner walls. The test group (TG) consisted of 10 titanium caps that were modified by MAO in an electrolyte solution containing calcium phosphate ions. The two types of titanium caps were fixed on the calvaria of 10 New Zealand rabbits. Each rabbit received two different caps. Although each cap was unfilled, the marrow and blood from the wound of the rabbit skulls could penetrate into the caps. After 4 weeks, the rabbits were sacrificed, and the skulls were removed for observation. The zenith of new bone was measured directly after the caps were removed from the skulls; subsequently, the bone volume was calculated by microcomputed tomography., Results: Little bone augmentation could be observed in the CG caps, and the new bone height of the CG group was inconspicuous. In contrast, the new bone extended along the inner walls of the TG caps. The mean height of new bone of the TG group was 2.3 ± 0.28 mm. The mean volume of new bone in the TG group was 18.63 ± 3.80 mm(3)., Conclusions: New bone formation in a titanium cap surface modified by MAO was greater than that of a nonmodified cap. A titanium cap allowed new bone formation on the MAO surface to be observed and is a promising device for bone augmentation. Additionally, this finding suggests that observation through a titanium cap is a feasible method for biomaterial testing in hard tissue.

Objective: Clinical criteria for periodontal wound healing/regeneration include wound stability, space-provision and conditions for primary intention healing. However, wound stability/space-provision may be difficult to obtain in non-contained periodontal defects. The objective of this study was to; using a limited, space-providing device as a conduit, evaluate a concept of space-provision sans tissue occlusion for periodontal wound healing/regeneration., Methods: Bilateral, critical-size, supraalveolar, periodontal defects were created in eight young adult Beagle dogs. One jaw quadrant received a limited, space-providing titanium mesh device, the contra-lateral jaw quadrant served as sham-surgery control followed by submerged wound closure for primary intention healing. The animals were euthanized at 8 weeks for histometric analysis of the surgical sites., Results: Clinical healing was generally uneventful; minor late exposures observed for some defects. Experimental sites exhibited significantly enhanced mean (±SE) bone and cementum regeneration compared with control (1.10 ± 0.20 and 1.32 ± 0.10 mm versus 0.34 ± 0.18 and 0.66 ± 0.15 mm; p < 0.01). A cellular mixed (extrinsic/intrinsic) fibre cementum and functionally oriented collagen fibres were routinely observed. Wound exposures were significantly associated with reduced bone formation (p < 0.05)., Conclusions: Using a limited, space-providing device to support periodontal wound healing/regeneration appears a promising clinical approach for non-contained periodontal defects., (© 2013 John Wiley & Sons A/S.)