Application of calcium sulfate as graft material in implantology and maxillofacial procedures: A review of literature.

Calcium sulphate (plaster of Paris) has been used since 1892 to fill bone defects and as a good bone graft substitute. Calcium sulphate is an osteoconductive, inorganic substance. Following 75 years, many other authors reported variable and a better result in grafting of bone defects and in several cases of immediate and delayed dental implants for good osseointegrations, with no complications attributed to the calcium sulphate. Early results were variable, because of its conflicting crystalline structure, purity, and quality of the calcium sulphate. Apart from this, calcium sulphate also shows predictable resorption rate in vivo, presence of minimal trace elements and extremely uniform crystalline structure. Calcium sulphate is a bio-inert material and get resorbed over a period of weeks and fibrovascular tissue takes its place which eventually allows neovascularization and bone formation within the area. Use During the conventional surgical treatment addition of calcium sulphate as a bone graft of in case of placement of dental implants and pathological bony defects it improves the clinical outcome. Calcium sulphate also act as a barrier and filling material for the treatment of "through and through" bony lesions. Use of calcium sulphate as a bone graft substitute avoids the complications and morbidity associated with autograft like infection, second surgery.

Guided bone regeneration at dehiscence comparing synthetic bone substitute versus bovine bone mineral: A multicenter, noninferiority, randomized trial.

AIM: To evaluate the efficacy of guided bone regeneration (GBR) for the treatment of peri-implant dehiscence defects using a synthetic bone substitute (SBS) or a deproteinized bovine bone mineral (DBBM) as a bone substitute. METHODS: Patients with expected dehiscence defects following implant placement were randomized to use either SBS or DBBM together with a bioabsorbable collagen membrane over dehiscenced implant surfaces aimed for GBR. The changes in the bone defect size were measured before the GBR procedure and 6 months after implant placement at the re-entry surgery. Secondary outcomes included peri-implant health outcomes, implant cumulative survival rates, bone level changes, and patient-reported outcomes (PROMs) at prosthesis delivery and 1-year follow-up. RESULTS: Of the 49 included patients, 24 were treated with SBS and 25 with DBBM. In the SBS group, the defect height (DH) at implant insertion was 5.1 ± 2.6 mm and was reduced at re-entry to 1.3 ± 2.0 mm (74.5%). In the DBBM group, the respective changes in DH were 4.1 ± 1.7 mm and 1.5 ± 1.9 mm (63.4%). These differences were not statistically significant (p = 0.216). The complete defect resolution rate was also comparable in both groups without statistical difference (62.5% of patients (15/24) vs. 44% of patients (11/25)). Overall, the marginal bone levels remained stable during the 1-year follow-up in both groups. CONCLUSION: The SBS is noninferior to DBBM for simultaneous GBR to implant placement at implant sites with buccal dehiscences in terms of defect resolution and evaluated secondary outcomes (KCT0008393 - this clinical trial was not registered before participant recruitment and randomization).

Fourteen-Year Follow-Up of a Patient With a Hydroxyapatite Ceramic Matrix Reconstruction of and a Bone Graft for a Critical-Size Cortical Bone Defect: A Case Report.

A 42-year-old man diagnosed with chondrosarcoma of the proximal femur underwent limb salvage by compartmental excision of the lesion and reconstruction with a custom-made hip prosthesis. The critical-size defect in the proximal femur was reconstructed with ceramic hemicylinders that were tied in place with sutures and augmented with two fibular strut grafts and an autologous cancellous iliac crest bone graft. A fourteen-year follow-up of the same case revealed that substituted ceramic matrices can be converted into dynamic, metabolically active, living bone.

Evaluation of Peri-Implantitis Bone Defect Healing: Comparing the Efficacy of Small-Particle Dentin and Bio-Oss in Bone Density Attenuation.

Introduction: Peri-implantitis is a serious complication in dental implantology that, if left untreated, may lead to implant loss and systemic diseases. Effective regeneration of bone defects resulting from peri-implantitis is crucial to maintaining the functionality of dental implants. Purpose of the Study: The study aimed to compare the effectiveness of fine-particle dentin and Bio-Oss in the reconstruction of bone defects caused by peri-implantitis. Materials and Methods: The study included a comprehensive radiological assessment of changes in bone density over time. Bone density was assessed using Hounsfield Units (HUs) as a measure of bone attenuation, with radiological assessments performed at 8- and 12-week intervals during the healing process. The study included participants ranging in age from 30 to 65 years. Fifty-seven patients were divided into three groups: 22 patients received small-particle dentin, 15 received Bio-Oss, and 20 controls without bone substitute material. Results: The fine-dentin group showed a 20% increase in bone density after 8 weeks (p < 0.05), while the Bio-Oss group showed a 15% increase after 12 weeks (p < 0.05). The control group showed minimal changes in bone density (5% after 12 weeks), which was not statistically significant. Clinical evaluations showed 95% successful integration in the fine dentin group, 85% in the Bio-Oss group, and 70% in the control group. The fine-dentin group showed a 20% increase in bone density after 8 weeks (p < 0.05), while the Bio-Oss group showed a 15% increase after 12 weeks (p < 0.05). The control group showed minimal changes in bone density (5% after 12 weeks), which was not statistically significant. Clinical evaluations showed 95% successful integration in the fine-dentin group, 85% in the Bio-Oss group, and 70% in the control group. Conclusions: Both fine-particle dentin and Bio-Oss significantly improved bone density compared to the control group. Fine-particle dentin is suitable for immediate bone regeneration due to its rapid initial regeneration, while Bio-Oss provides long-term support, ideal for maintaining implant stability over a longer period of time. The results highlight the importance of selecting appropriate bone replacement materials depending on the clinical scenario to improve patient outcomes after dental implant placement.

Bone Regeneration Capabilities of Scaffolds Containing Chitosan and Nanometric Hydroxyapatite-Systematic Review Based on In Vivo Examinations.

In this systematic review, the authors aimed to investigate the state of knowledge on in vivo evaluations of chitosan and nanometric hydroxyapatite (nanohydroxyapatite, nHAp) scaffolds for bone-tissue regeneration. In March 2024, an electronic search was systematically conducted across the PubMed, Cochrane, and Web of Science databases using the keywords (hydroxyapatite) AND (chitosan) AND (scaffold) AND (biomimetic). Methodologically, the systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocol to the letter. Initially, a total of 375 studies were screened, and 164 duplicates were removed. A further 188 articles were excluded because they did not correspond to the predefined topics, and an additional 3 articles were eliminated due to the inability to obtain the full text. The final compilation included 20 studies. All publications indicated a potential beneficial effect of the scaffolds in in vivo bone defect repair. A beneficial effect of hydroxyapatite as a scaffold component was observed in 16 studies, including greater mechanical resistance, cellular differentiation, and enhanced bone damage regeneration. The addition of chitosan and apatite ceramics, which combined the strengths of both materials, had the potential to become a useful bone-tissue engineering material.

Reinforcing ß-tricalcium phosphate scaffolds for potential applications in bone tissue engineering: impact of functionalized multi-walled carbon nanotubes.

Beta-tricalcium phosphate (ß-TCP) scaffolds manufactured through the foam replication method are widely employed in bone tissue regeneration. The mechanical strength of these scaffolds is a significant challenge, partly due to the rheological properties of the original suspension. Various strategies have been explored to enhance the mechanical properties. In this research, ß-TCP scaffolds containing varying concentrations (0.25-1.00 wt%) of multi-walled carbon nanotubes (MWCNT) were developed. The findings indicate that the addition of MWCNTs led to a concentration-dependent improvement in the viscosity of ß-TCP suspensions. All the prepared slurries exhibited viscoelastic behavior, with the storage modulus surpassing the loss modulus. The three time interval tests revealed that MWCNT-incorporated ß-TCP suspensions exhibited faster structural recovery compared to pure ß-TCP slurries. Introducing MWCNT modified compressive strength, and the optimal improvement was obtained using 0.75 wt% MWCNT. The in vitro degradation of ß-TCP was also reduced by incorporating MWCNT. While the inclusion of carbon nanotubes had a marginal negative impact on the viability and attachment of MC3T3-E1 cells, the number of viable cells remained above 70% of the control group. Additionally, the results demonstrated that the scaffold increased the expression level of osteocalcin, osteoponthin, and alkaline phosphatase genes of adiposed-derived stem cells; however, higher levels of gene expersion were obtained by using MWCNT. The suitability of MWCNT-modified ß-TCP suspensions for the foam replication method can be assessed by evaluating their rheological behavior, aiding in determining the critical additive concentration necessary for a successful coating process.

Improved new bone formation capacity of hyaluronic acid-bone substitute compound in rat calvarial critical size defect.

BACKGROUND: Bone loss of residual alveolar ridges is a great challenge in the field of dental implantology. Deproteinized bovine bone mineral (DBBM) is commonly used for bone regeneration, however, it is loose and difficult to handle in clinical practice. Hyaluronic acid (HA) shows viscoelasticity, permeability and excellent biocompatibility. The aim of this study is to evaluate whether high-molecular-weight (MW) HA combined with DBBM could promote new bone formation in rat calvarial critical size defects (CSDs). MATERIALS AND METHODS: Rat calvarial CSDs (5 mm in diameter) were created. Rats (n = 45) were randomly divided into 3 groups: HA-DBBM compound grafting group, DBBM particles only grafting group and no graft group. Defect healing was assessed by hematoxylin-eosin staining and histomorphometry 2, 4 and 8 weeks postop, followed by Micro-CT scanning 8 weeks postop. Statistical analyses were performed by ANOVA followed by Tukey's post hoc test with P < 0.05 indicating statistical significance. RESULTS: All rats survived after surgery. Histomorphometric evaluation revealed that at 2, 4 and 8 weeks postop, the percentage of newly formed bone was significantly greater in HA-DBBM compound grafting group than in the other two groups. Consistently, Micro-CT assessment revealed significantly more trabecular bone (BV/TV and Tb.N) in HA-DBBM compound group than in the other two groups, respectively (P < 0.05). Moreover, the trabecular bone was significantly more continuous (Tb.Pf) in HA-DBBM compound group than in the other two groups, respectively (P < 0.05). CONCLUSION: HA not only significantly promoted new bone formation in rats calvarial CSDs but also improved the handling ability of DBBM.

Alveolar Ridge Preservation Using a Novel Species-Specific Collagen-Enriched Deproteinized Bovine Bone Mineral: Histological Evaluation of a Prospective Case Series.

In recent years, the significance of maintaining the alveolar ridge following tooth extractions has markedly increased. Alveolar ridge preservation (ARP) is a commonly utilized technique and a variety of bone substitute materials and biologics are applied in different combinations. For this purpose, a histological evaluation and the clinical necessity of subsequent guided bone regeneration (GBR) in delayed implantations were investigated in a prospective case series after ARP with a novel deproteinized bovine bone material (95%) in combination with a species-specific collagen (5%) (C-DBBM). Notably, block-form bone substitutes without porcine collagen are limited, and moreover, the availability of histological data on this material remains limited. Ten patients, each scheduled for tooth extraction and desiring future implantation, were included in this study. Following tooth extraction, ARP was performed using a block form of C-DBBM in conjunction with a double-folded bovine cross-linked collagen membrane (xCM). This membrane was openly exposed to the oral cavity and secured using a crisscross suture. After a healing period ranging from 130 to 319 days, guided trephine drilling was performed for implant insertion utilizing static computer-aided implant surgery (s-CAIS). Cores harvested from the area previously treated with ARP were histologically processed and examined. Guided bone regeneration (GBR) was not necessary for any of the implantations. Histological examination revealed the development of a lattice of cancellous bone trabeculae through appositional membranous osteogenesis at various stages surrounding C-DBBM granules as well as larger spongy or compact ossicles with minimal remnants. The clinical follow-up period ranged from 2.5 to 4.5 years, during which no biological or technical complications occurred. Within the limitations of this prospective case series, it can be concluded that ARP using this novel C-DBBM in combination with a bovine xCM could be a treatment option to avoid the need for subsequent GBR in delayed implantations with the opportunity of a bovine species-specific biomaterial chain.

Optimizing Filament-Based TCP Scaffold Design for Osteoconduction and Bone Augmentation: Insights from In Vivo Rabbit Models.

Additive manufacturing has emerged as a transformative tool in biomedical engineering, offering precise control over scaffold design for bone tissue engineering and regenerative medicine. While much attention has been focused on optimizing pore-based scaffold architectures, filament-based microarchitectures remain relatively understudied, despite the fact that the majority of 3D-printers generate filament-based structures. Here, we investigated the influence of filament characteristics on bone regeneration outcomes using a lithography-based additive manufacturing approach. Three distinct filament-based scaffolds (Fil050, Fil083, and Fil125) identical in macroporosity and transparency, crafted from tri-calcium phosphate (TCP) with varying filament thicknesses and distance, were evaluated in a rabbit model of bone augmentation and non-critical calvarial defect. Additionally, two scaffold types differing in filament directionality (Fil and FilG) were compared to elucidate optimal design parameters. Distance of bone ingrowth and percentage of regenerated area within scaffolds were measured by histomorphometric analysis. Our findings reveal filaments of 0.50 mm as the most effective filament-based scaffold, demonstrating superior bone ingrowth and bony regenerated area compared to larger size filament (i.e., 0.83 mm and 1.25 mm scaffolds). Optimized directionality of filaments can overcome the reduced performance of larger filaments. This study advances our understanding of microarchitecture's role in bone tissue engineering and holds significant implications for clinical practice, paving the way for the development of highly tailored, patient-specific bone substitutes with enhanced efficacy.

Development of a composite using calcined bone powder and silane cross-linked alginate as bone substitute material.

Calcined bone is an attractive natural material for use as a bone substitute because of its cost-effectiveness and high biocompatibility, which are comparable to that of synthetic hydroxyapatite. However, the calcination process has significantly weakened the mechanical properties. In this study, a composite of calcined bovine bone powder reinforced with silane cross-linked alginate was prepared to assess its biocompatibility, osteoconductivity, and mechanical compatibility as a bone substitute material. Culture studies with osteoblast-like cells (MC3T3-E1) showed no cytotoxicity toward the composite and exhibited general cell proliferative properties in its presence. In contrast, the composite reduced the alkaline phosphatase activity of osteoblasts but led to significant noncellular apatite deposition on the surface. In addition, quasi-static compression tests of the composite revealed mechanical properties comparable to those of human cancellous bone. The mechanical properties remained stable under wet conditions and did not deteriorate significantly even after 2 weeks of immersion in simulated body fluid at 37°C. The results show that this composite, composed of calcined bone powder and silane cross-linked alginate, is a promising bone substitute material with biocompatibility, osteoconductivity, and mechanical compatibility.

Effectiveness of synthetic versus autologous bone grafts in foot and ankle surgery: a systematic review and meta-analysis.

BACKGROUND: All orthopaedic procedures, comprising foot and ankle surgeries, seemed to show a positive trend, recently. Bone grafts are commonly employed to fix bone abnormalities resulting from trauma, disease, or other medical conditions. This study specifically focuses on reviewing the safety and efficacy of various bone substitutes used exclusively in foot and ankle surgeries, comparing them to autologous bone grafts. METHODS: The systematic search involved scanning electronic databases including PubMed, Scopus, Cochrane online library, and Web of Science, employing terms like 'Bone substitute,' 'synthetic bone graft,' 'Autograft,' and 'Ankle joint.' Inclusion criteria encompassed RCTs, case-control studies, and prospective/retrospective cohorts exploring different bone substitutes in foot and ankle surgeries. Meta-analysis was performed using R software, integrating odds ratios and 95% confidence intervals (CI). Cochrane's Q test assessed heterogeneity. RESULTS: This systematic review analyzed 8 articles involving a total of 894 patients. Out of these, 497 patients received synthetic bone grafts, while 397 patients received autologous bone grafts. Arthrodesis surgery was performed in five studies, and three studies used open reduction techniques. Among the synthetic bone grafts, three studies utilized a combination of recombinant human platelet-derived growth factor BB homodimer (rhPDGF-BB) and beta-tricalcium phosphate (ß-TCP) collagen, while four studies used hydroxyapatite compounds. One study did not provide details in this regard. The meta-analysis revealed similar findings in the occurrence of complications, as well as in both radiological and clinical evaluations, when contrasting autografts with synthetic bone grafts. CONCLUSION: Synthetic bone grafts show promise in achieving comparable outcomes in radiological, clinical, and quality-of-life aspects with fewer complications. However, additional research is necessary to identify the best scenarios for their use and to thoroughly confirm their effectiveness. LEVELS OF EVIDENCE: Level II.

The efficacy of reconstructive therapy in the surgical management of peri-implantitis: A 3-year follow-up of a randomized clinical trial.

AIM: To assess whether guided bone regeneration (GBR) treatment of peri-implantitis-related bony defects could improve healing compared to open flap debridement (OFD) at 36 months. MATERIALS AND METHODS: In a multi-centre, randomized clinical trial, 32 individuals received OFD (control group [CG]) and 34 GBR treatment (test group [TG]). Radiographic defect fill (RDF), probing pocket depth (PPD), bleeding on probing (BOP) suppuration (SUP), mucosal recession (MREC) and patient-reported outcomes (PROs) were evaluated at 36 months. RESULTS: Fifty individuals attended a supportive peri-implant therapy program and completed the 36-month follow-up. GBR treatment resulted in an RDF of 2.13 ± 1.26 mm compared to 1.64 ± 1.54 mm following OFD (p = .18). No difference was found in PPD, BOP, SUP, REC or PROs between the groups. Successful treatment (no additional bone loss, PPD ≤ 5 mm, no BOP and no SUP) was achieved in 46.2% in TG and 20% in CG (p = .053). Treatment results obtained at 12 months were generally maintained up to 36 months. No significant changes were noticed between 12 and 36 months. CONCLUSIONS: At 36 months, treatment results obtained at 1 year were sustained following both GBR and OFD in patients attending supportive peri-implant therapy. GBR resulted in more RDF and higher composite treatment success rate than OFD (ClinicalTrials.gov Identifier [NCT02375750]).

Biphasic bone substitutes coated with PLGA incorporating therapeutic ions Sr2+ and Mg2+: cytotoxicity cascade and in vivo response of immune and bone regeneration.

The incorporation of bioactive ions into biomaterials has gained significant attention as a strategy to enhance bone tissue regeneration on the molecular level. However, little knowledge exists about the effects of the addition of these ions on the immune response and especially on the most important cellular regulators, the macrophages. Thus, this study aimed to investigate the in vitro cytocompatibility and in vivo regulation of bone remodeling and material-related immune responses of a biphasic bone substitute (BBS) coated with metal ions (Sr2+/Mg2+) and PLGA, using the pure BBS as control group. Initially, two cytocompatible modified material variants were identified according to the in vitro results obtained following the DIN EN ISO 10993-5 protocol. The surface structure and ion release of both materials were characterized using SEM-EDX and ICP-OES. The materials were then implanted into Wistar rats for 10, 30, and 90 days using a cranial defect model. Histopathological and histomorphometrical analyses were applied to evaluate material degradation, bone regeneration, osteoconductivity, and immune response. The findings revealed that in all study groups comparable new bone formation were found. However, during the early implantation period, the BBS_Sr2+ group exhibited significantly faster regeneration compared to the other two groups. Additionally, all materials induced comparable tissue and immune responses involving high numbers of both pro-inflammatory macrophages and multinucleated giant cells (MNGCs). In conclusion, this study delved into the repercussions of therapeutic ion doping on bone regeneration patterns and inflammatory responses, offering insights for the advancement of a new generation of biphasic calcium phosphate materials with potential clinical applicability.

Fabrication and histological evaluation of a self-setting granular cement using calcium sulfate hemihydrate granules with different pore distribution.

Granular type of bone substitutes is currently used in the field of dentistry to restore alveolar bone defects. However, the migration of the granules from the implantation site is still an unresolved issue. In this study, the feasibility to fabricate self-setting calcium sulfate hemihydrate (CSH) granules using different ranges of loading pressure: CSH(0), CSH(50), CSH(100), and CSH(150) was investigated with the hypothesis that CSH granules with reduced microporosity can inhibit the rapid dissolution rate of the calcium sulfate dihydrate (CSD) set blocks and induce bone regeneration. After 4 weeks of implantation, the granules were mostly replaced with new bone although no significant differences were observed. Nevertheless, the granules demonstrated the ability to set within the bone defect. It is therefore concluded that the setting ability of calcium sulfate can contribute to address the issue of migration of the granules and provide a useful guide for designing setting bone substitutes.

Pull-Out Strength of Orthodontic Miniscrews in the Temporal Bone.

BACKGROUND: Minimally invasive cochlear implant surgery by using a microstereotactic frame demands solid connection to the bone. We aimed to determine the stability of commercially available orthodontic miniscrews to evaluate their feasibility for frame's fixation. In addition, which substitute material most closely resembles the mechanical properties of the human temporal bone was evaluated. METHODS: Pull-out tests were carried out with five different types of orthodontic miniscrews in human temporal bone specimens. Furthermore, short fiber filled epoxy (SFFE), solid rigid polyurethane (SRPU50), bovine femur, and porcine iliac bone were evaluated as substitute materials. In total, 57 tests in human specimens and 180 tests in the substitute materials were performed. RESULTS: In human temporal bone, average pull-out forces ranged from 220 N to 285 N between screws. Joint stiffness in human temporal bone ranged between 14 N/mm and 358 N/mm. Statistically significant differences between the tested screws were measured in terms of stiffness and elastic energy. One screw type failed insertion due to tip breakage. No significant differences occurred between screws in maximum pull-out force. The average pull-out values of SFFE were 14.1 N higher compared to human specimen. CONCLUSION: Orthodontic miniscrews provided rigid fixation when partially inserted in human temporal bone, as evidenced by pull-out forces and joint stiffness. Average values exceeded requirements despite variations between screws. Differences in stiffness and elastic energy indicate screw-specific interface mechanics. With proper insertion, orthodontic miniscrews appear suitable for microstereotactic frame anchoring during minimally invasive cochlear implant surgery. However, testing under more complex loading is needed to better predict clinical performance. For further pull-out tests, the most suitable substitute material is SFFE.

Biphasic Calcium Phosphate in the Extraction Socket Preservation: A Systematic Review.

Introduction: Various studies have suggested use of socket grafting materials after dental extraction for socket preservation. However, there is no single material that has been accepted as standard for preserving the socket. The purpose of this systematic review was to analyze the evidence for the use of biphasic calcium phosphate for socket regeneration. Materials and Methods: The team conducted a systematic literature search in accordance with the protocol registered at PROSPERO. PubMed, OVID, and EMBASE databases were used in the search. The articles were then screened using RAYYAN open-source software for the synthesis of evidence. Results: Of the 240 articles found in the search, two studies could be included in the review. Conclusion: Biphasic calcium phosphate (60% hydroxyapatite, HA and 40% beta-tricalcium phosphate, ß-TCP) has a significant effect in the socket preservation and quality of bone regeneration.

The effect of a barrier membrane on the incorporation of deproteinized bovine bone mineral (DBBM) in experimental defects at the time of early implant placement. A preclinical study.

OBJECTIVES: This study aimed to assess membrane use with a bone substitute graft for guided bone regeneration (GBR) in experimental dehiscence defects. MATERIALS AND METHODS: Maxillary second incisors (I2) in 9 dogs were extracted. Six weeks later, implants were inserted and experimental dehiscence defects (5 × 3 mm) created on the buccal aspect. The defects and surrounding bone were grafted with deproteinized bovine bone mineral. One side (test) was covered with a resorbable collagen membrane whereas the contralateral side (control) was not. After 6 weeks, histomorphometrical analysis was performed to evaluate: (a) first bone-to-implant contact (fBIC), (b) buccal bone thickness at 1 mm increments from implant shoulder, (c) regenerated area (RA), (d) area and percentages of new bone (B), bone substitute (BS) and mineralized tissue (MT). RESULTS: The histological appearance was similar between test and control sites. At central and lateral sections, there were no differences between groups for fBIC, buccal bone thickness, RA, BS, B, %B, MT and %MT. At central sections, membrane use favoured more %BS and %MT (p = 0.052). There was significantly more B, %B and MT at lateral compared to central sections. CONCLUSIONS: Membrane use tended to retain more bone substitute, but had no effect on new bone ingrowth. Lateral sections showed significantly more bone ingrowth and mineralized tissue compared to central sections, confirming that new bone ingrowth takes place mainly from the lateral walls of the defect. CLINICAL RELEVANCE: Preclinical research to clarify the dynamics of bone regeneration in GBR procedures is relevant in clinical practice.

TPMS Microarchitectures for Vertical Bone Augmentation and Osteoconduction: An In Vivo Study.

Triply periodic minimal surface microarchitectures (TPMS) were developed by mathematicians and evolved in all kingdoms of living organisms. Renowned for their lightweight yet robust attributes, TPMS structures find application in diverse fields, such as the construction of satellites, aircrafts, and electric vehicles. Moreover, these microarchitectures, despite their intricate geometric patterns, demonstrate potential for application as bone substitutes, despite the inherent gothic style of natural bone microarchitecture. Here, we produced three TPMS microarchitectures, D-diamond, G-gyroid, and P-primitive, by 3D printing from hydroxyapatite. We explored their mechanical characterization and, further, implanted them to study their bone augmentation and osteoconduction potential. In terms of strength, the D-diamond and G-gyroid performed significantly better than the P-primitive. In a calvarial defect model and a calvarial bone augmentation model, where osteoconduction is determined as the extent of bony bridging of the defect and bone augmentation as the maximal vertical bone ingrowth, the G-gyroid performed significantly better than the P-primitive. No significant difference in performance was observed between the G-gyroid and D-diamond. Since, in real life, the treatment of bone deficiencies in patients comprises elements of defect bridging and bone augmentation, ceramic scaffolds with D-diamond and G-gyroid microarchitectures appear as the best choice for a TPMS-based scaffold in bone tissue engineering.

Tissue changes around dental implants installed in alveolar ridge preservation sites: A 1-year follow-up randomized controlled clinical trial.

OBJECTIVE: This study aimed to assess radiographic marginal bone changes 22 months post extraction, which is 1 year after implant loading in alveolar ridge preservation (ARP) sites grafted with a combination of collagen-embedded xenogenic bone substitute (DBBM-C) and collagen matrix (CMX), comparing them with implants placed in naturally healed sites. METHODS: This randomized controlled clinical trial was conducted over 22 months. Patients who needed a single tooth extraction and subsequent implant placement in nonmolar areas were enrolled. The test group received deproteinized bovine bone mineral with 10% collagen covered by a procaine collagen membrane, while the control group allowed spontaneous healing. Radiographic bone level changes were documented using periapical radiographs at implant placement and follow-up visits (6, 10, and 22 months postextraction). Early implant soft tissue exposure, clinical parameters, and patient-reported outcomes were recorded. RESULTS: Twenty-two out of 28 participants completed a 22-month follow-up, 9 in the test group and 13 in the control group. At 10-month postextraction follow-up, the mean MBL was 1.01 ± 1.04 mm in the treatment group and 0.81 ± 0.93 mm in the control group (p = 0.804). At 22 months, the mean MBL was 2.09 ± 1.03 mm in the treatment group and 1.58 ± 0.73 mm in the control group (p = 0.339). No statistically significant differences in probing depth (PD) and bleeding on probing (BOP) were found at the 22 -month follow-up as well. Soft tissue mean recession was observed in the control group (0.36 ± 0.84 mm), while no recession was found in the test group (p = 0.2). Early implant soft tissue exposure occurred in 33% of test group participants, while none was observed in the control group (p = 0.047). CONCLUSION: One year after implant loading, no significant differences in marginal bone resorption were found between implants placed in ARP-treated and naturally healed sites. However, ARP-treated sites exhibited early implant soft-tissue exposure, suggesting a possible impairment in soft tissue healing.

Three-dimensional imaging analysis of CAD/CAM custom-milled versus prefabricated allogeneic block remodelling at 6 months and long-term follow-up of dental implants: A retrospective cohort study.

AIM: This retrospective cohort study aimed to volumetrically investigate the bone stability rate of prefabricated allogeneic bone blocks (PBB) and computer-aided design (CAD)/computer-aided manufacturing (CAM) custom-milled allogeneic bone blocks (CCBB) for ridge augmentation. MATERIALS AND METHODS: Nineteen patients were treated with 20 allografts: 11 CCBB, 9 PBB; 10 in the maxilla and 10 in the mandible. Clinical treatment history and cone beam computed tomography scans before surgery (t0), directly after graft surgery (t1) and after 6 months of healing prior to implant insertion (t2) were evaluated using a three-dimensional evaluation software for absolute bone volume, stability as well as vertical and horizontal bone gain. Furthermore, the inserted implants were analysed for survival, marginal bone loss (MBL) and complications for a mean follow-up period of 43.75 (±33.94) months. RESULTS: A mean absolute volume of 2228.1 mm3 (±1205) was grafted at t1. The bone stability rate was 87.6% (±9.9) for CCBB and 83.0% (±14.5) for PBB. The stability was higher in the maxilla (91.6%) than in the mandible (79.53%). Surgery time of PBB was longer than for CCBB (mean Δ = 52 min). The survival rate of the inserted implants was 100% with a mean MBL of 0.41 mm (±0.37). CONCLUSION: The clinical performance of both allograft block designs was equally satisfactory for vertical and horizontal bone grafting prior to implant placement. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT06027710.