Porcine Collagen Membrane Research Articles

Osseointegration of Anodized vs. Sandblasted Implant Surfaces in a Guided Bone Regeneration Acute Dehiscence-Type Defect: An InVivo Experimental Mandibular Minipig Model.

This controlled preclinical study analyzed the effect of implant surface characteristics on osseointegration and crestal bone formation in a grafted dehiscence defect minipig model. A standardized 3 mm × 3 mm acute-type buccal dehiscence minipig model grafted with deproteinized bovine bone mineral and covered with a porcine collagen membrane after 2 and 8 weeks of healing was utilized. Crestal bone formation was analyzed histologically and histomorphometrically to compare three implant groups: (1) a novel, commercially available, gradient anodized (NGA) implant, to two custom-made geometric replicas of implant "1," (2) a superhydrophilic micro-rough large-grit sandblasted and acid-etched surface, and (3) a relatively hydrophobic micro-rough large-grit sandblasted and acid-etched surface. At 2 and 8 weeks, there was no difference between the amount and height of newly formed bone (NBH, new bone height; BATA, bone area to total area) for any of the groups (p > 0.05). First bone-to-implant contact (fBIC) and vertical bone creep (VBC) at 2 and 8 weeks were significantly increased for Groups 2 and 3 compared to Group 1 (p < 0.05). At 8 weeks, osseointegration in the dehiscence (dehiscence bone-implant-contact; dBIC) was significantly higher for Groups 2 and 3 compared to Group 1 (p < 0.05). The amount of newly formed bone (BATA) and NBH was not influenced by surface type. However, moderately rough surfaces demonstrated significantly superior levels of osseointegration (dBIC) and coronal bone apposition (fBIC) in the dehiscence defect compared to the NGA surface at 2 and 8 weeks. For this type of study, clinical trial registration is not required. This study was conducted at the Biomedical Department of Lund University (Lund, Sweden) and approved by the local Ethics Committee of the University (M-192-14).

Does alveolar ridge preservation reduce the need for sinus floor elevation: A comparative study to spontaneous healing.

In cases of atrophy in the maxillary posterior region, characterized by reduced vertical bone volume, implant placement becomes challenging. Augmentation procedures like sinus lifts are often needed to address insufficient bone volume. This study aims to explore if alveolar ridge preservation, using a bovine bone substitute and a porcine collagen membrane, significantly decreases the need for sinus lifts compared to natural wound healing after tooth extraction. In this comparative clinical study, 40 patients requiring a total of 53 extractions were assigned to one of the following groups: a test group with bovine bone substitute material (Straumann® XenoFlex) and a porcine collagen membrane (Jason® membrane), or a control group with spontaneous socket healing. After 6 months, digital volume tomography was performed for implant planning. For seven patients from the control group (n = 22 extracted sites) sinus lift augmentations were performed while only four sinus lift procedures were performed in the test group (n = 31 extracted sites), indicating a higher need for sinus augmentation procedures in the control group, however not statistically different on a p value of 0.05 (p = 0.168). In the control group, the mean value of the radiographically measured bone height (mesial and distal) was 11.13 ± 2.12 mm preoperatively before tooth extraction, while it was 11.3 ± 2.17 mm postoperatively after implant placement. In contrast, the mean value in the test group was 11.78 ± 3.09 mm preoperatively and 11.92 ± 2.79 mm postoperatively. Statistical analysis revealed no significant difference between the two groups (odds ratio 0.32; 95% CI: 0.08, 1.26; p = 0.951). The implant survival rate in the control group was 100%, compared to 96.77% in the test group. Within the limits of this study, the use of bovine bone substitute and a porcine resorbable membrane after tooth extraction in the posterior maxilla seems to reduce the need for sinus augmentation in comparison to spontaneous healing although the difference was not statistically significant. Additionally, the Alveolar Ridge Preservation in the test group made external sinus floor elevation unnecessary compared to the control group. The change in radiographically measured bone height pre- and postoperatively showed no significant difference between the two groups.

Treatment of Complex Multiple Lesions in the Knee With MACI (Autologous Cultured Chondrocytes on Porcine Collagen Membrane)

Background: Multiple chondral lesions in the knee are difficult to manage. A few treatment options are available. Considering the number of lesions, size, location, and total surface area, the autologous cultured chondrocytes on porcine collagen membrane (MACI) technique can effectively treat multiple defects simultaneously. Indications: The MACI procedure is indicated for multiple chondral lesions in the knee with large surface areas when other technologies are hard to implement or lack sufficient follow-up. Technique Description: The chondral defects are debrided to subchondral bone with vertical walls. Concomitant procedures are to be completed before MACI implantation. Each defect is treated as an isolated lesion. Irregular and uncontained lesions require a unique approach. A single membrane can treat multiple lesions; however, careful presurgery analysis is necessary to analyze the requirement of an additional membrane. Results: The MACI technique for multiple lesions in the knee has a good response rate and high satisfaction scores over mid- to long-term follow-up. Discussion/Conclusions: Multiple chondral lesions of the knee can effectively be treated with MACI, providing patients with additional improved quality of life, increasing level of function, and possibly delaying total knee arthroplasty procedures. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Healing patterns of alveolar bone following ridge preservation procedures.

Examine the histomorphometric bone composition, following alveolar ridge preservation techniques and unassisted socket healing. Forty-two patients (42) requiring a single rooted tooth extraction were randomly allocated into three groups (n = 14 per group): Group 1: Guided Bone Regeneration (GBR) using deproteinised bovine bone mineral (DBBM) and a porcine collagen membrane; Group 2: Socket Seal (SS) technique using DBBM and a porcine collagen matrix; Group 3: Unassisted socket healing (Control). Trephined bone biopsies were harvested following a 4-month healing period. Forty-two samples underwent Back-Scattered Electrons -Scanning Electron Microscopy (BSE-SEM) imaging, with 15 samples examined using Xray Micro-Tomography (XMT) (n = 6 for each GBR/SS and n = 3 Control). Images were analysed to determine the percentage (%) of connective tissue, new bone formation, residual DBBM particles and direct bone to DBBM particle contact (osseointegration). BSE-SEM analysis demonstrated that new bone formation was higher in the Control (45.89% ± 11.48) compared to both GBR (22.12% ± 12.7/p < .004) and SS (27.62% ± 17.76/p < .005) groups. The connective tissue percentage in GBR (49.72% ± 9), SS (47.81% ± 12.57) and Control (47.81% ± 12.57) groups was similar. GBR (28.17% ± 16.64) and SS (24.37% ± 18.61) groups had similar levels of residual DBBM particles. XMT volumetric analysis indicated a lower level of bone and DBBM particles in all test groups, when matched to the BSE-SEM area measurements. Osseointegration levels (DBBM graft and bone) were recorded at 35.66% (± 9.8) for GBR and 31.18% (± 19.38) for SS. GBR and SS ARP techniques presented with less bone formation when compared to unassisted healing. GBR had more direct contact/osseointegration between the DBBM particles and newly formed bone.

Evaluation of Porcine Collagen Membranes Used with Guided Bone Regeneration for Critical Defects: A Histological, Histomorphometric, Immunohistochemical, and Inflammatory Profile Analysis.

The objective of this study was to compare the effectiveness of two porcine collagen membranes of different origin used for guided bone regeneration procedures. Resorbable collagen membrane from porcine dermis (Bio-Gide, Geistlich Pharma AG, Wolhusen, Switzerland) and resorbable collagen membrane from porcine pericardium (Jason, Institut Straumann AG, Peter Merian-Weg, Switzerland) were evaluated; histological, histometric, immunohistochemical, and inflammatory profile analyses were performed. The study was carried out on critical defects created in the calvaria of 72 rats (Rattus norvegicus albinus, Wistar variety) divided into three groups: coagulum group (Co), porcine pericardium group (JS), and porcine collagen group (BG). The defects were filled with clot, over which the membranes were placed. The animals were euthanized 7, 15, 30, and 60 days after surgery. The Shapiro-Wilk test was used to assess data distribution. Analysis of variance (ANOVA) and the Bonferroni multiple comparison test were used to compare the differences across the mean values of the variables. Nonparametric tests, Mann-Whitney and Wilcoxon W, were used for the quantitative analysis of the inflammatory profile. A significance level of 5% (p < 0.05) was adopted with a confidence interval of 95%. SPSS software version 2.0 was used. A total of 1,008 analyses were performed on 288 histological slides. It was noted that both types of collagen membranes used in this study were effective for the guided bone regeneration procedure, with a greater proportion and thickness of bone formation among recipients of the BG (735 points, p = 0.021). This membrane also had greater permeability (62.25). The animals in the JS group, which received the porcine pericardial membrane, showed early and accelerated bone formation from early bone tissue, milder osteopontin and osteocalcin levels, and greater inflammatory reaction (86.4). The collagen membrane from porcine dermis demonstrated a more orderly and physiological repair process, while the porcine pericardial membrane presented a more accelerated repair process that did not remain constant over time.

All-Arthroscopic Matrix-Associated Autologous Chondrocyte Implantation for a Trochlear Defect

Matrix-associated autologous chondrocyte implantation (MACI) is a 2-step technique designed to treat symptomatic full-thickness articular cartilage defects of the knee. In this technique article, MACI (autologous cultured chondrocytes on porcine collagen membrane) is used to treat a femoral trochlear defect of the knee. Treating a defect with this technique leads to improved clinical outcomes by restoring the native chondral surface architecture and biomechanics of the knee. In addition, it has the potential to prevent or delay further progressive degeneration of the joint. It is a 2-stage procedure consisting of an initial arthroscopic cartilage biopsy, followed by 4 to 6 weeks of in vitro chondrocyte expansion and, finally, re-implantation. We recommend performing the MACI procedure arthroscopically for the second stage to treat a femoral trochlear defect. During the second surgical procedure, we examine and prepare the recipient site, followed by graft introduction in an all-arthroscopic manner via dry scoping, secured by a thin layer of fibrin glue.

MACI Sandwich Technique With Autologous Bone Graft

Background: Osteochondral lesions of the knee are difficult to manage. Such lesions can be effectively treated with the matrix-induced autologous chondrocyte implantation (MACI) “sandwich” technique using autologous chondrocytes on porcine collagen membrane in conjuction with autologous cancellous bone grafting (ABG). Few studies have examined this technique to restore the osteochondral unit. Indications: The MACI “Sandwich” procedure is indicated when osteochondral lesions are larger than 2 cm2 in size and deeper than 8 to 10 mm, with symptoms consistent with the location of the lesion. Technique Description: The chondral defect is radically debrided back to healthy bone and cartilage tissue. The base of the bony cavity is drilled to enhance the vascular supply and promote healing. Next, the bony cavity is prepared to slightly undermine the subchondral bone surface around the articular margins, with the depth of the cavity wider than the opening, similar to a dental amalgam. The autologous cancellous bone is subsequently morselized and impacted up to the level of the native subchondral bone plate. The first MACI membrane with the cells facing up is placed directly onto the bone graft site and compressed with a neural patty. The neural patty is removed, and the second MACI membrane is then placed with the cells facing down. The edges are then micro-sutured to ensure stability. Results: The “sandwich” technique has superior survival rates compared with autologous bone grafting alone, with patients reporting decreased pain, improved function, and high satisfaction scores over a mid-term to long-term follow-up. Discussion/Conclusion: The MACI “sandwich” technique is an effective surgical intervention to restore the osteochondral unit and preserve the patient's native knee joint. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Decontamination and Repair Protocol Promotes Positive Outcomes in Implants Affected by Peri-implantitis: A Human Case Series.

This study assessed the effectiveness and predictability of a readily available protocol to treat peri-implantitis utilizing mechanical debridement, chemical antiseptic surface detoxification, and osseous grafting. Nine patients (7 women, 2 men; mean age: 56.5 years) with 15 implants with peri-implantitis were included. Pocket probing depth (PPD), bleeding on probing (BOP), and standardized digital periapical radiographic measurements were taken. Surgical flaps were elevated, and the implant threads were cleaned with a plastic curette. Chemical decontamination was performed by scrubbing solutions of 0.25% sodium hypochlorite (NaClO) and 1.5% hydrogen peroxide (H2O2) around the exposed implant using cotton pellets. Bony defects were filled with a 50/50 mixture of bovine hydroxyapatite and nanocrystalline calcium sulfate (CaSO4). A porcine collagen membrane was placed over the grafted bony defect. Follow-up appointments were scheduled 1 week, 2 weeks, 3 months, 6 months, 9 months, and 1 year posttreatment. Clinical and radiographic parameters were assessed and compared. At baseline, PPD ranged from 5 to 7.5 mm (mean: 6 ± 0.7 mm). At 12 months, PPD ranged from 1.5 to 4.2 mm (mean: 2.5 ± 0.8 mm). The mean PPD reduction of 3.6 mm (59.2%) was statistically significant (P < .001). The number of bleeding sites around each test implant decreased significantly from 4 to 0.4 sites between baseline and 12 months (P < .001). Mean radiographic bone loss decreased from 4.8 ± 1.3 mm to 2.7 ± 1.2 mm (P < .001). The proposed method of mechanical decontamination, chemical detoxification, and bone regeneration is clinically effective and reproducible. Clinical peri-implant parameters and radiographic bone levels were improved and maintained their stability for 1 year using this peri-implantitis treatment protocol.

Surface topography of resorbable porcine collagen membranes, and their effect on early osteogenesis: An in vitro study

ObjectiveGuided tissue regeneration (GTR) is based on the use of different membranes that function as sealants and barriers in specific clinical situations. Among the several tissue production methods and origins, resorbable porcine-derived membranes are the most commonly used. Because these membranes are so diverse, and have several different clinical applications, doubts linger as to their effect in stimulating osteogenesis. The objective of this study was to make an in vitro evaluation of the viability and differentiation of osteoblastic cells cultured on the surface of the following collagen membranes: Jason® (Botiss Biomaterials), Collprotect® (Botiss Biomaterials), and Bio-Gide® (Geistlich). Material and methodsFragments of the 3 resorbable collagen membranes (5 × 5 mm) were used, and pre-osteoblastic SAOS-2 cells (ATCC, USA) were plated on their porous surfaces. Evaluation of the membranes was performed at 3, 5 and 7 days, considering the following parameters: (1) topographic analysis of the different surfaces by scanning electron microscope; (2) cellular viability by MTT, (3) quantification of type I collagen and osteopontin by Elisa. The quantitative analyses were carried out using a significance level of 5%. ResultsCollprotect® and Jason® membranes presented a rough surface with an irregular aspect on both sides, while double-layered Bio-Gide® had one layer with a smooth surface and the other with a rough surface along each respective length. The viability assays revealed that the cells cultured the cells grown on Collprotect® showed higher viability than those grown in Bio-Gide® or Jason®, especially after 5 and 7 days. After 3 and 5 days, evaluation of type I collagen showed that the cells plated on the Jason® and Collprotect® surfaces had greater collagen secretion than those plated on BioGide®. After 7 days, an increase in osteopontin levels was observed when the cells were plated on all the experimental membranes, compared with the control group. ConclusionAll the tested membranes were suitable for use in GTR clinical procedures. Their indication in specific regenerative cases depends on the mechanical and biological properties of their originating tissues, thus enabling better results and assertive choices by dental professionals.

Clinical and histomorphometric soft tissue assessment comparing free gingival graft (FGG) and a collagen matrix (MS) as alveolar-sealer materials: a randomized controlled pilot clinical trial.

This study aimed to compare the alveolar sealing performance between free gingival graft (FGG) and porcine collagen membrane (MS) and qualitatively assessed patient-centered outcomes via a visual analog scale (VAS). Eighteen patients were randomly divided into control (FGG) and test (MS) groups. After extraction, all the alveoli were filled with bovine bone grafts (small granules) and sealed. The follow-up happened during the immediate post-operatory period and after 3, 7, 15, 30, 60, 90, and 120 days. After 180 days, before implant placement, tissue samples were obtained for histological analysis. The epithelial tissues were morphometrically measured for each sample. Qualitative information on the patient's perception of the treatment was collected after seven days. A faster healing was observed for the MS group. After 60 days, all the sites from the MS were partially healed, in contrast with only five from the FGG. The histological results after 120 days showed for the FGG group an acute inflammatory predominant process, whereas for the MS group was observed chronic processes. The mean epithelial height found for the FGG and MS were 535.69μm and 495.33μm (p=0.54). The intragroup analysis showed significant variance among the data (p<0.001) for both groups. The qualitative result showed statistically more significative comfort for the MS group (p<0.05). Within the limitation of this study, both techniques effectively promote alveolar sealing. However, the VAS result found a better and more significant result for the MS group, with faster wound healing and lower discomfort.

Clinical observation of Porcine Collagen Membrane + artificial Bovine Bone Granules Guided tissue regeneration combined with Autologous CGF in the treatment of severe periodontitis bone defect.

To investigate and analyze the clinical observation of porcine collagen membrane + artificial bovine bone granules guided tissue regeneration (GTR) combined with autologous concentration of growth factors (CGF) in the treatment of severe periodontitis bone defect. A total of 94 patients with severe periodontitis bone defects admitted to Shanxi Bethune Hospital from January 2019 to January 2022 were included. They were divided into two groups by simple randomization method. Patients in the control group were treated with porcine collagen membrane + artificial bovine bone granules GTR, while those in the observation group were treated with autologous CGF on the basis of the control group. Before and after treatment, periodontal clinical indicators [sulcus bleeding index (SBI), gingival retreat index (GR), probing depth (PD), clinical attachment loss (CAL), alveolar bone height (AH)] and bone resorption markers [Osteoprotegerin (OPG), bone gla protein (BGP), Type-1 collagen N-terminal peptide (NTX)] were compared between the two groups, and the incidence of postoperative complications in the two groups was recorded. The total efficacy of observation group was significantly higher than that of control group (p<0.05). Three months after surgery, the observation group had lower levels of SBI, PD, CAL and NTX while higher levels of GR, AH, OPG and BGP than the control group (p<0.05). There was no significant difference in complication rate between the two groups (p>0.05). Porcine collagen membrane + artificial bovine bone granules GTR combined with autologous CGF boasts various benefits in the treatment of severe periodontitis bone defects, such as improvement of clinical outcomes, amelioration of periodontal tissue and inhibition of bone resorption.

Purified porcine collagen membrane modulates integration of polypropylene mesh implant in a rat model

Old women are expected to undergo pelvic organ prolapse (POP) surgery. Distress caused by POP affects women´s quality of life. Although polypropylene mesh (PM) is considered a good material to restore the pelvic floor, there are concerns about infection and vaginal mesh exposure. This research studies the optic properties of inflammatory reaction and the tissue repair induced by a PM covered by porcine collagen membrane (CM). Thirty female rats were shared in two groups: (A) exposed to PM covered by CM and (B) exposed to PM alone; five animals each group were euthanized at day 7, 14 and 28 of post-operation day (POD). Collagen anisotropic properties were analyzed. In the 7⍛PO group A pushes vascular proliferation on, as lymphocytes and fibroblasts infiltration. Group B evidenced amount of histiocytes and beginning of encapsulating. At the 14⍛PO group A keeps the characteristics of lymphocytic infiltration and rounding the PM there is a thin layer of fat tissue separating it from the muscles layer; Group B evidenced amount of fibroblasts rounding the PM and multinucleated giant cells crushed by a wrap of collagen and fibroblasts. The 28⍛PO group A revealed big fibroblasts process with expressive histiocytes presence. Group B shows much multinucleated giant cells trying to wrap up the polypropylene, a considerate decreased infiltration, and the striated muscles layer infiltrated the implanted area. PM covered with a highly purified porcine collagen membrane showed earlier resolution of inflammatory reaction, better neoangiogenesis and more organized host collagen deposition than in pure PM.

Injectable Hydrogel Membrane for Guided Bone Regeneration.

In recent years, multicomponent hydrogels such as interpenetrating polymer networks (IPNs) have emerged as innovative biomaterials due to the synergistic combination of the properties of each network. We hypothesized that an innovative non-animal IPN hydrogel combining self-setting silanized hydroxypropyl methylcellulose (Si-HPMC) with photochemically cross-linkable dextran methacrylate (DexMA) could be a valid alternative to porcine collagen membranes in guided bone regeneration. Calvaria critical-size defects in rabbits were filled with synthetic biphasic calcium phosphate granules in conjunction with Si-HPMC; DexMA; or Si-HPMC/DexMA experimental membranes; and in a control group with a porcine collagen membrane. The synergistic effect obtained by interpenetration of the two polymer networks improved the physicochemical properties, and the gel point under visible light was reached instantaneously. Neutral red staining of murine L929 fibroblasts confirmed the cytocompatibility of the IPN. At 8 weeks, the photo-crosslinked membranes induced a similar degree of mineral deposition in the calvaria defects compared to the positive control, with 30.5 ± 5.2% for the IPN and 34.3 ± 8.2% for the collagen membrane. The barrier effect appeared to be similar in the IPN test group compared with the collagen membrane. In conclusion, this novel, easy-to-handle and apply, photochemically cross-linkable IPN hydrogel is an excellent non-animal alternative to porcine collagen membrane in guided bone regeneration procedures.

MACI (autologous cultured chondrocytes on porcine collagen membrane) in patients 40 years and older: short-term clinical outcomes and patient satisfaction

IntroductionCartilage restoration in the middle-aged population (40-60 years) is understudied. ObjectivesThe purpose of this study is to report the clinical outcomes and satisfaction of patients over the age of 40 years old who underwent autologous cultured chondrocytes on porcine collagen membrane (MACI) for the treatment of degenerative articular cartilage lesions in the knee. MethodsThe study included 30 patients who were over 40 years of age (mean 48.6 ± 5.5 years, range 41-60 years). Patients included were treated by a single surgeon from 2017 to 2020. Clinical outcome data was available for 29 patients at a minimum 2-year follow-up (mean 39.6 ± 9.6 months). All patients with intact MACI grafts completed a satisfaction questionnaire. The mean lesion surface area transplanted was 11.5 ± 6.6 cm2. The mean number of defects transplanted was 2.5 ± 1.0. Treatment failure was defined as delamination of the MACI graft with associated clinical symptoms and/or progression of osteoarthritis. ResultsOf the 29 patients, 6 (21%) had a graft failure. Three patients went on to osteochondral allograft transplantation, 1 patient experienced symptomatic improvement with debridement, and 2 patients underwent total knee arthroplasty. Twenty-seven of the 29 patients (93%) maintained their native knee. Of those with intact MACI grafts, 17 out of 23 (74%) rated their knee as “good” or “excellent” and 16 out of 23 (70%) were satisfied with their surgery. ConclusionsMACI is effective in the short-term in patients over the age of 40 years old with degenerative articular cartilage lesions to maintain their native knee. A moderate degree of satisfaction was achieved in most patients.

Application of Tissue Engineering in Manufacturing Absorbable Membranes to Improve the Osteopromoting Potential of Collagen.

The membranes are an important biomaterial that contribute to osteopromotion. This study aimed to evaluate the osteopromotive potential of collagen membranes associated with Hydroxyapatite (HA) in critical size calvaria rat's defects. Ninety-six Albinus Wistar rats were divided into four groups: (CG) negative control: clot only (CG); positive control: porcine collagen membrane (BG); fish collagen membrane associated with HA (CP); bovine collagen membrane associated with HA (CB), analyzed at 7, 15, 30, and 60 postoperative days. At 30 days, membrane integrity was observed in the CB and fragments in the CP and BG groups were dispersed in the center of the defect. At 60 days, BG demonstrated better results with no statistical difference for the CP group (p = 0.199) and a statistically significant difference for the CB group (p = 0.013). The inflammatory profiles of the BG and CP groups were similar. Immunohistochemistry demonstrated at 60 days moderate osteopontin staining for the BG and CP groups, light staining for the CB, and intense osteocalcin staining for the BG, while the CB and CP groups demonstrated moderate staining. Microtomography revealed the highest mean bone volume (14.247 mm3) in the BG, followed by the CB (11.850 mm3), and CP (9.560 mm3) group. The collagen membranes associated with HA demonstrated an osteopromotive potential.

Prospective Clinical Study with New Materials for Tissue Regeneration: A Study in Humans.

This study was performed to evaluate the clinical, radiographic, and histomorphometric outcomes of novel bone grafting materials and dental membranes and to compare the results with current data from the literature. New synthetic bone substitutes, consisting of biphasic calcium phosphate in the ratio of 60% hydroxyapatite and 40% β-tricalcium phosphate, were applied in bony defects and covered by either a novel synthetic poly(lactic-co-glycolic) acid (PLGA) or porcine collagen membrane. A sample of 51 biomaterials was placed in a total of 20 patients during different surgical protocols. Implants were simultaneously inserted, and in the case of sinus floor elevations 6 months later. Pre- and postoperative cone-beam computed tomographies were taken. Bone biopsies were harvested from augmented sides and processed for histomorphometric evaluation. Averages and ranges were calculated for the percentage of newly formed bone, residual biomaterial, and connective tissue. Data were submitted to analyze the radiological mean differences in length, width, and density. Paired t-tests were deployed for the analysis of differences within each group between the baseline (preoperative) and the final (postoperative) measurements. The mean bone gain in length and width were 0.96 ± 3.33 mm (+27.59%) and 1.22 ± 1.87 mm (+30.48%), respectively. The bone density was increased by a factor of 4, reaching an average of 387.47 ± 328.86 HU. Histomorphometric evaluations revealed new bone formation of 41.44 ± 5.37%, residual biomaterial of 24.91 ± 7.31%, and connective tissue of 33.64 ± 4.81%. The mean healing period was 8.32 ± 3.00 months. Data from this study confirmed the suitability of the tested materials in dental surgery. The biomaterials may be recommended for various clinical procedures. A satisfactory level of increase of new bone was reported in augmented sides. No significant differences were observed between the tested membranes. PLGA membranes might be superior to collagen membranes for their easier handling.

Biocompatibility Assessment of Two Commercial Bone Xenografts by In Vitro and In Vivo Methods.

Bone substitutes based on xenografts have been used for a long time in bone regeneration thanks to their inductive capacity for bone tissue regeneration. Some bone-based scaffolds have been modified by adding collagen and other proteins to improve their regenerative capacity and prevent migration and aggregation, especially particles. However, rejection of this graft has been reported due to protein residues caused by poor material preparation. We compared the in vitro and in vivo biological response of two commercial xenografts (InterOss®, F1 and InterOss® Collagen, F2) and a commercial porcine collagen membrane (InterCollagen® Guide, F3) as a rapid degradation control. Fourier Transform Infrared Spectroscopy (FT-IR) analysis evidenced the presence of hydroxyl, orthophosphate, and carbonate groups of the xenografts and amide groups of collagen. Thermogravimetric analysis (TGA) of the xenografts demonstrated their thermal stability and the presence of a few amounts of organic material. The study by differential scanning calorimetry showed the presence of endothermic peaks typical of the dehydration of the xenografts (F1 and F2) and for the collagen membrane (F3), the beginning of structural three-dimensional protein changes. Subsequently, in vitro biocompatibility tests were carried out for the materials with Artemia salina and MTT cell viability with HeLa cells, demonstrating the high biocompatibility of the materials. Finally, in vivo biocompatibility was studied by implanting xenografts in biomodels (Wistar rats) at different periods (30, 60, and 90 days). The F1 xenograft (InterOss) remained remarkably stable throughout the experiment (90 days). F2 (InterOss Collagen) presented a separation of its apatite and collagen components at 60 days and advanced resorption at 90 days of implantation. Finally, the collagen membrane (F3) presented faster resorption since, at 90 days, only some tiny fragments of the material were evident. All the in vivo and in vitro test results demonstrated the biocompatibility of the xenografts, demonstrating the potential of these materials for tissue engineering.

Calvaria Critical Size Defects Regeneration Using Collagen Membranes to Assess the Osteopromotive Principle: An Animal Study.

Guided bone regeneration (GBR) is a common practice in implantology, and it is necessary to use membranes in this process. The present study aimed to evaluate the osteopromotive principle of two porcine collagen membranes in critical-size defects at rats calvaria. Ninety-six Albinus Wistar rats were divided into BG (positive control), JS, CS, and CG (negative control) groups and were sacrificed at 7, 15, 30, and 60 days postoperatively. The samples were assessed by histological, histometric, immunohistochemical, and microtomographic analyses. More intense inflammatory profile was seen in the JS and CS groups (p < 0.05). At 60 days, the JS group showed a satisfactory osteopromotive behavior compared to BG (p = 0.193), while CS did not demonstrate the capacity to promote bone formation. At the immunohistochemical analysis, the CS showed mild labeling for osteocalcin (OC) and osteopontin (OP), the JS demonstrated mild to moderate for OC and OP and the BG demonstrated moderate to intense for OC and OP. The tridimensional analysis found the lowest average for the total volume of newly formed bone in the CS (84,901 mm2), compared to the BG (319,834 mm2) (p < 0.05). We conclude that the different thicknesses and treatment techniques of each membrane may interfere with its biological behavior.

Guided Tissue Regeneration Treatment Yields Better Results in Class II Furcations in the Mandible Than in the Maxilla: A Retrospective Study.

Absorbable porcine collagen membrane with a bovine bone graft can be considered for regenerative treatment in periodontal class II furcation defects. We evaluated the clinical efficacy of guided tissue regeneration (GTR) treatment with bovine bone xenograft and a porcine collagen membrane in molars with class II furcations. Probing depth (PD), clinical attachment level (CAL), and bone level (BL) were recorded at baseline and at 3, 6, and 9 months postoperatively. Thirty class II furcation defects from the lower and upper molars were assessed. Significant improvements in PD and CAL were observed from baseline to 9 months in all groups (p < 0.01). BL improved in all groups except group A in the upper molars in radiographic assessment (p < 0.05). The lower and upper molars showed PD reduction of 50.5% ± 7.44% and 46.2% ± 11.2%, respectively, at 9 months (p = 0.044). In furcations of 1–3 mm, the lower and upper molars showed PD reductions of 51.2% ± 4.49% and 36.5% ± 16.14%, respectively (p = 0.035). The lower and upper molars showed a CAL gain of 51.1% ± 4.64% and 33.6% ± 18.8%, respectively (p = 0.037). Thus, GTR with bovine bone graft and porcine collagen membrane yielded good results in class II furcations, with better results in the lower than in the upper molars.

COMPARISON OF ADHESION AND PROLIFERATION OF MESENCHYMAL STEM CELLS ON AMNIOTIC MEMBRANE AND COLLAGEN PORCINE-DERIVED SCAFFOLD

<h3>Background</h3> Cellular scaffolds are 3D structures that support cell adhesion and proliferation, promoting an environment favorable to cell culture. The amniotic membrane (AM) is a scaffold that has suitable mechanical properties, low immune rejection and low cost of obtaining and processing. The mesenchymal stem cells (MSC) are known for their immunomodulatory capacity, maintenance and renewal of cells and tissues, and its association with AM may have a great potential in tissue engineering. The aim of this study was to compare the capacity of adhesion and proliferation of dental pulp-derived MSC (DPSC) after cultivation on decellularized AM with the commercial porcine collagen membrane (CPCM) already used clinically. <h3>Methods</h3> The AM was collected, isolated and decellularized. The DPSC were obtained from permanent tooth pulp by mechanical dissociation followed by enzymatic digestion and expanded in vitro. The DPSC were genetically modified to express the luciferase enzyme. These transfected cells were plated at different concentrations: 10,000, 30,000, 50,000 and 100,000 per cm² on AM and CPCM, and used in bioluminescence analysis to assess adherence and proliferation capacity on both scaffolds over 24 hours, 7 days, 14 days, 21 days and 28 days. <h3>Results</h3> The concentration of 100,000 cells per cm² showed better adhesion in all tested samples. There was a significant difference (<i>p</i> = 0.004) 24 hours after cell culture, with CPCM presenting five times more cells than AM. The difference was also observed on the 7th day (<i>p</i> = 0.011), with CPCM presenting eight times more cells than AM. On the 14th and 21st days (<i>p</i> = 0.006 and p = 0.004, respectively), CPCM showed a considerable decrease in cell proliferation. At the same time, AM presented an increase in cell proliferation, with two times more cells than CPCM. Finally, there was a significant difference on the 28th day (<i>p</i> = 0.010), where AM presented three times more cells than CPCM. <h3>Conclusion</h3> The results showed AM is a viable source to be used as a scaffold for cell adhesion and proliferation. When extrapolated to an in vivo environment, it is possible that CPCM's showed more difficulty in maintaining cell adhesion for more than a week which could affect clinical outcomes. In this scenario, AM it seems to be a more stable scaffold, enabling cell adhesion for up to three weeks. The presented technology proved to be accessible, reproducible, and can be an alternative to commercial membranes.