Guided Bone Regeneration Procedures Research Articles

Survival analysis of dental implants placed in horizontally severely resorbed maxillae after reconstruction with xenogeneic graft: a case series.

To evaluate the survival rates of dental implants with a hybrid macrostructure and the surface biomimetically coated with nanohydroxyapatite, placed in horizontally atrophic maxillae previously submitted to the guided bone regeneration (GBR) procedure, associated with the use of a deproteinized bovine bone graft (DBB). Twenty-five patients who received 196 implants were involved in this study. First, these patients were submitted to GBR procedures and maxillary sinus lift, where DBB was used as the grafting material. The dental implants were placed after a minimum period of 6 months of the grafting procedures. The patients were followed up every six months and clinical/radiographic examinations were performed to assess the implants, using the following indicators as a reference: (1) Absence of mobility; (2) Absence of pain. Data about the age, surgery time, smoking status, implant size, and time between the grafting procedure and implant placement were correlated with implant failures. Twelve implants failed, generating a survival rate of 94.23%. None of the variables analysed correlated with the implant failures. Implants with a hybrid macrostructure and surface biomimetically coated with nanohydroxyapatite present good survival rates in horizontally atrophic maxillae grafted with DBB.

Bredigite bioceramic-based barrier membrane promotes guided bone regeneration by orchestrating an immuno-modulatory and osteogenic microenvironment

Barrier membranes play an important role in guided bone regeneration (GBR) and have been primarily considered as physical barriers. Due to their inherent “foreign body” properties, barrier membranes introduced during GBR procedures unavoidably modify the local immune microenvironment, with consequent impacts on osteogenesis. In bone tissue engineering applications, inorganic bioceramics have been shown to possess the abilities to modulate the local immune response and promote the differentiation of stem cells along osteogenic lineages. Moreover, these bioceramics can be easily incorporated into scaffold membranes, thus demonstrating significant potential as a barrier membrane material for GBR. Herein, an inorganic bredigite (BRT, Ca7MgSi4O16) bioceramic-containing scaffold was fabricated and characterized, and its effects on the immune response and osteogenesis during GBR were investigated. The results indicated that the BRT-containing scaffolds promoted the migration and osteogenic differentiation of bone marrow-derived stem cells (BMSCs). Single-cell RNA sequencing analysis indicated a unique microenvironment and subpopulation of BMSCs cultured on the BRT scaffolds, which exhibited increased osteo/chondrogenic and angiogenic differentiation potential. Furthermore, the BRT-containing scaffolds induced macrophage polarization into the pro-regenerative M2 phenotype, which subsequently promoted the migration and osteogenic differentiation of BMSCs. Additionally, in an in vivo rat model, the BRT-containing membrane was confirmed to enhance the immune microenvironment and support bone regeneration in a cranial critical-size defect. Collectively, these findings indicate that the BRT-containing scaffold membrane possesses dual immunomodulatory and osteogenic properties, offering a potentially beneficial GBR membrane for clinical application.

New Bone Growth into Surgical Bone Defects Grafted with a Novel Cultivated Coral Graft: A Histomorphometric Study in Rabbit Calvarias.

Natural Coral Particles (NCPs) are a suitable scaffold material for Guided Bone Regeneration (GBR) procedures; it combines the placement of a bone substitute supporting a barrier membrane. Due to increasing sea pollution and the declarations of endangered coral species (KYOTO 1997), they are no longer suitable for the medical industry. Novel domestic corals have been grown under controlled conditions to produce cultivated coral graft (CCG) material. This study aimed to evaluate a new CCG in an in vivo experimental GBR procedure. The calvarias of 8 rabbits were surgically exposed, and circular defects 8 mm in diameter were prepared. One defect was filled with CCG particles (experimental group); the contralateral defect (control group) was spontaneously filled by blood clot. The defects were covered with a collagen membrane. Animals were euthanized after 8 weeks. Histological observations of the defects showed similar bone growth patterns in both experimental and control osteotomies. In the experimental defects, no traces of coral particles were observed. Histometric analysis showed denser bone in the pristine zone (65-66%) than in the peripheral zone for both the control (50%) and experimental defects (31%) (P= NS). The new bone percentage was reduced from the peripheral zone toward the middle and the center of the defect (31%, 32% and 27%, respectively) as the distance from the peripheral pristine bone borders increased. The existing data support the complete degradation of CCG as space-maintaining scaffold for GBR procedures.

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.

Development of Novel Polysaccharide Membranes for Guided Bone Regeneration: In Vitro and In Vivo Evaluations.

Guided bone regeneration (GBR) procedures require selecting suitable membranes for oral surgery. Pullulan and/or dextran-based polysaccharide materials have shown encouraging results in bone regeneration as bone substitutes but have not been used to produce barrier membranes. The present study aimed to develop and characterize pullulan/dextran-derived membranes for GBR. Two pullulan/dextran-based membranes, containing or not hydroxyapatite (HA) particles, were developed. In vitro, cytotoxicity evaluation was performed using human bone marrow mesenchymal stem cells (hBMSCs). Biocompatibility was assessed on rats in a subcutaneous model for up to 16 weeks. In vivo, rat femoral defects were created on 36 rats to compare the two pullulan/dextran-based membranes with a commercial collagen membrane (Bio-Gide®). Bone repair was assessed radiologically and histologically. Both polysaccharide membranes demonstrated cytocompatibility and biocompatibility. Micro-computed tomography (micro-CT) analyses at two weeks revealed that the HA-containing membrane promoted a significant increase in bone formation compared to Bio-Gide®. At one month, similar effects were observed among the three membranes in terms of bone regeneration. The developed pullulan/dextran-based membranes evidenced biocompatibility without interfering with bone regeneration and maturation. The HA-containing membrane, which facilitated early bone regeneration and offered adequate mechanical support, showed promising potential for GBR procedures.

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

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

Guided Tissue and Bone Regeneration Membranes: A Review of Biomaterials and Techniques for Periodontal Treatments.

This comprehensive review provides an in-depth analysis of the use of biomaterials in the processes of guided tissue and bone regeneration, and their indispensable role in dental therapeutic interventions. These interventions serve the critical function of restoring both structural integrity and functionality to the dentition that has been lost or damaged. The basis for this review is laid through the exploration of various relevant scientific databases such as Scopus, PubMed, Web of science and MEDLINE. From a meticulous selection, relevant literature was chosen. This review commences by examining the different types of membranes used in guided bone regeneration procedures and the spectrum of biomaterials employed in these operations. It then explores the manufacturing technologies for the scaffold, delving into their significant impact on tissue and bone regenerations. At the core of this review is the method of guided bone regeneration, which is a crucial technique for counteracting bone loss induced by tooth extraction or periodontal disease. The discussion advances by underscoring the latest innovations and strategies in the field of tissue regeneration. One key observation is the critical role that membranes play in guided reconstruction; they serve as a barrier, preventing the entry of non-ossifying cells, thereby promoting the successful growth and regeneration of bone and tissue. By reviewing the existing literature on biomaterials, membranes, and scaffold manufacturing technologies, this paper illustrates the vast potential for innovation and growth within the field of dental therapeutic interventions, particularly in guided tissue and bone regeneration.

Comparison of bombyx mori l. Fibroin coatings on the mechanical properties of collagen membranes

Background: Most of dental implants are accompanied by guided bone regeneration (GBR) procedures. Collagen membrane which is the most widely used type of membrane in the GBR procedure has the disadvantage of not having antimicrobial properties, old bone formation, easy to tear, and soft so that it does not maintain the dimensions of the augmentation area. Bombyx mori L. fibroin has good mechanical properties and has the potential to be used as a pharmaceutical material that is biocompatible, antimicrobial, and stimulates bone growth. The aim of this study was to analyze the effect of Bombyx mori L. fibroin coating on the mechanical properties of collagen membranes.&#x0D; Method: The samples consisted of the control group (group A) and the treatment group, the collagen membrane was coated using the Bombyx mori L dip-coating fibroin technique, namely group B (1 time coating process), group C (2 times coating process) and group D (3 times the coating process). Statistical analysis used one-way ANOVA (p

In vivo evaluation of bone regeneration using ZIF8-modified polypropylene membrane in rat calvarium defects.

The profound potential of zeolitic imidazolate framework 8 (ZIF8) thin film for inducing osteogenesis has been previously established under in vitro conditions. As the next step towards the clinical application of ZIF8-modified substrates in periodontology, this in vivo study aimed to evaluate the ability of the ZIF8 crystalline layer to induce bone regeneration in an animal model defect. Following the mechanical characterization of the membranes and analysing the in vitro degradation of the ZIF8 layer, in vivo bone regeneration was evaluated in a critical-sized (5-mm) rat calvarial bone defect model. For each animal, one defect was randomly covered with either a polypropylene (PP) or a ZIF8-modified membrane (n = 7 per group), while the other defect was left untreated as a control. Eight weeks post surgery, bone formation was assessed by microcomputed tomography scanning, haematoxylin and eosin staining and immunohistochemical analysis. The ZIF8-modified membrane outperformed the PP membrane in terms of mechanical properties and revealed a trace Zn+2 release. Results of in vivo evaluation verified the superior barrier function of the ZIF8-coated membrane compared with pristine PP membrane. Compared with the limited marginal bone formation in the control and PP groups, the defect area was almost filled with mature bone in the ZIF8-coated membrane group. Our results support the effectiveness of the ZIF8-coated membrane as a promising material for improving clinical outcomes of guided bone regeneration procedures, without using biological components.

Efficacy of mixture of injectable-platelet rich fibrin and type-1 collagen particles on the closure of through-and-through periapical bone defects - A randomized controlled trial.

To determine the efficacy of a combination of injectable-platelet rich fibrin and type-1 collagen particles on the healing of through-and-through periapical bone defect and subsequent closure of bony window. The clinical trial was registered in ClinicalTrials.gov(NCT04391725). Thirty eight individuals with radiographic evidence of periapical radiolucency in maxillary anterior teeth and confirmed loss of palatal cortical plates in cone beam computed tomographic imaging were randomly assigned to either experimental group(n=19) or the control group(n=19). Mixture of i-PRF and collagen as a graft was applied to the defect in adjunct to periapical surgery in experimental group. No guided bone regeneration procedures were used in the control group. The healing was evaluated using Molven's(2D) and modified PENN 3D(3D) criteria. Percentage reduction of the buccal and palatal bony window area, and complete closure of through-and-through periapical bony window (tunnel defect) were assessed using Radiant Diacom viewer software(Version 4.0.2). The reduction in the periapical lesion area and volume was measured using Corel DRAW and ITK Snap software. Thirty four participants(18 and 16 in the experimental and control group, respectively) reported for follow-up at 12 months. There was 96.9% and 97.96% reduction of buccal bony window area in experimental and control groups respectively. Similarly, palatal window showed 99.03% and 100% reduction in experimental and control groups respectively. No significant difference in both buccal and palatal window reduction was noticed between the groups. A total of 14 cases(7 in experimental and 7 in control group) showed complete closure of through-and-through bony window. No significant difference in clinical, 2D and 3D radiographic healing, percentage reduction in area and volume was observed between experimental and control group(P>0.05). Neither the area nor the volume of lesion, and the size of buccal or palatal window had significant effect on healing of through-and-through defects. Endodontic microsurgery results in high success rate in large peripical lesions with through-and-through communication with more than 80% reduction in volume of lesion and size of both buccal and palatal window after one year. Mixture of type-1 collagen particles and i-PRF, adjunct to periapical micro-surgery did not improve the healing in through-and-through periapical defects.

A Synthetic Bio-Absorbable Membrane in Guided Bone Regeneration in Dehiscence-Type Defects: An Experimental In Vivo Investigation in Dogs.

This study aimed to determine the performance and characteristics of a synthetic barrier membrane of polylactic acid and acetyl butyl citrate (PLAB) for the lateral bone augmentation of peri-implant dehiscence defects (mean height × depth = 3 mm × 1 mm). In eight dogs, three treatment groups were randomly allocated at each chronic peri-implant dehiscence-type defect: (i) a deproteinized bovine bone mineral covered by a synthetic barrier membrane (test group), (ii) a deproteinized bovine bone mineral covered by a natural collagen membrane (positive control), and (iii) a synthetic barrier membrane (negative control). After 4 and 12 weeks of submerged healing, dissected tissue blocks were processed for calcified and decalcified histological analysis. Histometric measurements for tissue and bone width were performed, and bone-to-implant contact and alkaline phosphatase expression where measured. After 4 and 12 weeks of healing, no statistical differences between the groups were observed for the histometric measurements. The expression of alkaline phosphatase was higher in the positive control group after 4 weeks followed by the positive and negative controls (5.25 ± 4.09, 4.46 ± 3.03, and 4.35 ± 2.28%, p > 0.05) and 12 weeks followed by the negative and positive controls (4.3 ± 2.14, 3.21 ± 1.53, and 2.39 ± 1.03%, p > 0.05). Concerning the bone-to-implant contact, after 4 weeks, the test group obtained the highest results (39.54 ± 48.7) vs. (31.24 ± 42.6) and (20.23 ± 36.1), respectively, while after 12 weeks, the positive control group obtained the highest Bone to imaplant contact (BIC) results, followed by the test and negative controls, (35.91 ± 24.9) vs. (18.41 ± 20.5) and (24.3 ± 32.1), respectively; no statistically significant differences were obtained. Within the limitations of the study, new bone formation can be achieved in guided bone regeneration procedures simultaneously with implant placement either with the use of a PLAB membrane or a native collagen membrane, although these differences were not statistically significant.

Decellularized periosteum promotes guided bone regeneration via manipulation of macrophage polarization.

Periosteum has shown potential as an effective barrier membrane for guided bone regeneration (GBR). However, if recognized as a "foreign body," insertion of a barrier membrane in GBR treatment will inevitably alter the local immune microenvironment and subsequently influence bone regeneration. The aim of this investigation was to fabricate decellularized periosteum (DP) and investigate its immunomodulatory properties in GBR. DP was successfully fabricated from periosteum from the mini-pig cranium. In vitro experiments indicated that the DP scaffold modulated macrophage polarization toward a pro-regenerative M2 phenotype, which in turn facilitated migration and osteogenic differentiation of bone marrow-derived mesenchymal stem cells. A rat GBR model with a cranial critical-size defect was established, and our in vivo experiment confirmed the beneficial effects of DP on the local immune microenvironment and bone regeneration. Collectively, the findings of this study indicate that the prepared DP possesses immunomodulatory properties and represents a promising barrier membrane for GBR procedures.

Full-Digital Customized Meshes in Guided Bone Regeneration Procedures: A Scoping Review

Meshes, especially titanium ones, are being widely applied in oral surgery. In guided bone regeneration (GBR) procedures, their use is often paired with membranes, being resorbable or non-resorbable. However, they present some limitations, such as difficulty in the treatment of severe bone defects, alongside frequent mesh exposure. Customized meshes, produced by a full-digital process, have been recently introduced in GBR procedures. Therefore, the focus of the present review is to describe the main findings in recent years of clinical trials regarding patient-specific mesh produced by CAD/CAM and 3D printing workflow, made in titanium or even PEEK, applied to GBR surgeries. The purpose is to analyze their clinical management, advantages, and complications. This scoping review considered randomized clinical trials, observational studies, cohort studies, and case series/case reports studies. Studies that did not meet inclusion criteria were excluded. The preferred reporting items for scoping reviews (PRISMA-ScR) consensus was followed. A total of 15 studies were selected for this review. Based on the studies included, the literature suggests that meshes produced by a digital process are used to restore complex and severe bone defects. Moreover, they give satisfactory aesthetic results and fit the defects, counteracting grid exposure. However, more clinical trials should be conducted to evaluate long-term results, the rate of complications, and new materials for mesh manufacturing.

Predictability of osseointegrated implants installed in guided bone regeneration areas: a retrospective study

Objective: To evaluate the predictability and success rate of implants installed in extraction sites, where the Guided Bone Regeneration (GBR) technique for bone preservation and implant placement was performed. Methods: This is a retrospective study, which included medical records of patients from the clinic of the Specialization in Implantology course from the educational institution, who underwent GBR in the tooth socket with indicated extraction, who delivered the tomographic exams, and had implants installed in these places, from 2007 to 2016. Forty-two participants were included in the research, totaling 55 sites divided into two groups: maxilla and mandible. Results: Two cases (3.7%) of non-bone formation were found after GBR, in the posterior region of the maxilla, with a success rate of 96.3% for predictability of implant placement in GBR sites. Of the 53 implants installed where there was sufficient bone formation, 3 (5.7%) did not return to the clinic and, therefore, 50 were evaluated, with 48 presenting clinical osseointegration with a success rate of 96%. Conclusion: There is predictability of GBR procedures in post-extraction sockets for the installation of osseointegrated implants.

Progression of experimental peri-implantitis in guided bone regeneration and pristine bone: A preclinical in vivo study.

Guided bone regeneration (GBR) is the most widely used technique for overcoming the deficiency of alveolar bone. However, the progression of peri-implantitis in regenerative and pristine bone sites has not been fully investigated. The aim of this study is to compare experimental peri-implantitis around implants placed in pristine bone and GBR sites. Bilateral mandibular first molars were extracted from six beagle dogs, and standardized horizontal ridge defectwas simultaneously created at predetermined site in unilateral mandible. After 8weeks, guided bone regeneration procedure was conducted at the defect site. After 16 weeks, implants (ϕ 3.6×8.0mm) were placed at both extracted sites. This study included 3 months of active breakdown and another 3 months of spontaneous progression period. Radiographs were taken at each phase and specimens were obtained for histological, immunohistochemical, and polarized light microscopic analysis. Marginal bone loss around implant did not show the significant differences between pristine bone and GBR sites during spontaneous progression period. In immunohistochemical analysis, inflammatory and immune-related cells were predominantly detected in peri-implantitis-affected area rather than unaffected area. In the polarized light microscopic analysis, substantial reductions in the amount and thickness of collagen fibers were observed in peri-implantitis-affected area compared with unaffected tissues. However, there were no significant differences in histological, immunohistochemical, polarized light microscopic outcomes between pristine bone and GBR sites. Previous hard tissue grafting at the implant sites did not affect experimental peri-implantitis and exhibited similar radiographic, histological, immunohistochemical, and polarized light microscopic outcomes compared with those of pristine bone sites.

Polydioxanone Dome Technique for Guided Bone Regeneration: Surgical Technique and Results up to 72 Months of Follow-up.

This study aimed to describe the step-by-step procedure of the polydioxanone dome technique associated with guided bone regeneration (GBR) and to report the results up to 72 months after implant loading. Patients with maxillary horizontal bone defects (< 5 mm residual width, confirmed by CBCT scan) were treated with the proposed intervention. During the GBR procedure, four bone perforations were strategically prepared in a roughly square configuration. Segments of polydioxanone suture material were introduced in the perforations, forming a dome-shaped structure. Six months after bone augmentation, a new CBCT was performed. After implant restoration, periapical radiographs were taken, which were then repeated annually. The following outcomes were analyzed: implant survival, horizontal bone gain, marginal bone level, and complications. Twenty implants were placed in 11 patients with a survival rate of 100% in a mean follow-up of 38.18 ± 19.65 months after loading. Mean horizontal bone gain was 3.82 ± 1.67 mm and mean marginal bone level was -0.12 ± 1.17 mm. Only minor complications were observed. The present results suggest that the polydioxanone dome technique may represent a promising approach during horizontal GBR, alone or in combination with implant placement. Int J Periodontics Restorative Dent 2023;43:223-230. doi: 10.11607/prd.6087.

Effect of the Lateral Bone Augmentation Procedure in Correcting Peri-Implant Bone Dehiscence Defects: A 7-Years Retrospective Study

Guided bone regeneration (GBR) is a well-documented and widely-used dental surgical procedure for the treatment of various types of alveolar bone defects. The aim of the study was to evaluate the long-term effectiveness of the GBR procedure in correcting small peri-implant bone dehiscence using the xenogeneic deproteinized bovine bone mineral material and a xenogeneic native bilayer collagen membrane. The present study was designed as a retrospective study. Seventy-five bone-level tapered two-piece dental implants Conelog®, Camlog (Biotechnologies AG, Switzerland) were divided into two groups G1—no bone augmentation (no GBR)—44 implants and G2—bone augmentation (GBR)—31 implants. For both groups, the closed healing protocol with a primary wound closure was used. The incidence of peri-implantits was evaluated, the quantitative assessment of soft tissue thickness was performed using the ultrasound (USG) device, quantitative assessment of marginal bone loss (MBL) was done. The prevalence of peri-implantitis was 5.3%, with a three-fold increase in peri-implantitis comparing the groups without and with bone augmentation (G1 = 2.27%, G2 = 9.7%). The average keratinized gingiva thickness was 1.87 mm and did not differ significantly between groups. No statistically significant differences in MBL between G1 and G2 were found. When dividing patients by gender, no statistically significant differences were observed. When dividing patients by age groups, statistically significant differences were observed between the youngest and oldest groups of patients. Within the limitations of this study, it can be concluded that the use of xenogeneic bone and a xenogeneic collagen membrane in a GBR procedure can be recommended to correct small peri-implant bone dehiscence.

Fast Degradable Calcium Phosphate Cement for Maxillofacial Bone Regeneration.

The aim of this preclinical study was to test the applicability of calcium phosphate cement (CPC)-poly(lactic-co-glycolic acid) (PLGA)-carboxymethylcellulose (CMC) as a bone substitute material for guided bone regeneration (GBR) procedures in a clinically relevant mandibular defect model in minipigs. In the study, a predicate device (i.e., BioOss®) was included for comparison. Critical-sized circular mandibular bone defects were created and filled with either CPC-PLGA-CMC without coverage with a GBR membrane or BioOss covered with a GBR membrane and left to heal for 4 and 12 weeks to obtain temporal insight in material degradation and bone formation. Bone formation increased significantly for both CPC-PLGA-CMC and BioOss with increasing implantation time. Further, no significant differences were found for bone formation at either 4 or 12 weeks between CPC-PLGA-CMC and BioOss. Finally, bone substitute material degradation increased significantly for both CPC-PLGA-CMC and BioOss from 4 to 12 weeks of implantation, showing the highest degradation for CPC-PLGA-CMC (∼85%) compared to BioOss (∼12%). In conclusion, this minipig study showed that CPC-PLGA-CMC can be used as a bone-grafting material and stimulates bone regeneration to a comparable extent as with BioOss particles. Importantly, CPC-PLGA-CMC degrades faster compared to BioOss, is easier to apply into a bone defect, and does not need the use of an additional GBR membrane. Consequently, the data support the further investigation of CPC-PLGA-CMC in human clinical trials. Impact statement Guided bone regeneration (GBR) is a frequently used dental surgical technique to regenerate the alveolar ridge to allow stable implant installation. However, stabilization of the GBR membrane and avoidance of bone graft movement remain a challenge. Consequently, there is need for the development of alternative materials to be used in GBR procedures that are easier to apply and induce predictable bone regeneration. In this minipig study, we focused on the applicability of calcium phosphate cement-poly(lactic-co-glycolic acid)-carboxymethylcellulose as an alternative bone substitute material for GBR procedures without the need of an additional GBR membrane.

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.

Evaluation of the clinical and radiographic effectiveness of treating peri-implant bone defects with a new biphasic calcium phosphate bone graft: a prospective, multicenter randomized controlled trial.

Biphasic calcium phosphate (BCP), a widely used biomaterial for bone regeneration, contains synthetic hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), the ratio of which can be adjusted to modulate the rate of degradation. The aim of this study was to evaluate the clinical and radiographic benefits of reconstructing peri-implant bone defects with a newly developed BCP consisting of 40% β-TCP and 60% HA compared to demineralized bovine bone mineral (DBBM). This prospective, multicenter, parallel, single-blind randomized controlled trial was conducted at the periodontology departments of 3 different dental hospitals. Changes in clinical (defect width and height) and radiographic (augmented horizontal bone thickness) parameters were measured between implant surgery with guided bone regeneration (GBR) and re-entry surgery. Postoperative discomfort (severity and duration of pain and swelling) and early soft-tissue wound healing (dehiscence and inflammation) were also assessed. Data were compared between the BCP (test) and DBBM (control) groups using the independent t-test and the χ² test. Of the 53 cases included, 27 were in the test group and 26 were in the control group. After a healing period of 18 weeks, the full and mean resolution of buccal dehiscence defects were 59.3% (n=16) and 71.3% in the test group and 42.3% (n=11) and 57.9% in the control group, respectively. There were no significant differences between the groups in terms of the change in mean horizontal bone augmentation (test group: -0.50±0.66 mm vs. control groups: -0.66±0.83 mm, P=0.133), postoperative discomfort, or early wound healing. No adverse or fatal complications occurred in either group. The GBR procedure with the newly developed BCP showed favorable clinical, radiographic, postoperative discomfort-related, and early wound healing outcomes for peri-implant dehiscence defects that were similar to those for DBBM. Clinical Research Information Service Identifier: KCT0006428.