Evaluation of Porcine-Derived Collagen Membranes for Soft Tissue Augmentation in the Oral Cavity: An In Vivo Study.

The use of porcine-derived collagen membranes (PDCM) to improve intraoral soft tissue rehabilitation remains under investigation. Different degrees of crosslinking have yielded differences in resorption time and inflammation surrounding collagen membranes. The aim of this study was to evaluate the in vivo performance of bilayered PDCMs with varying degrees of crosslinking for the regeneration of oral soft tissue defects. Bilateral split-thickness oral mucosa defects were created in mandibles of beagles (n=17) and assigned to one of the following: bilayer PDCM (high crosslinking porcine dermis in sheet form-H-xlink) and (low crosslinking porcine dermis in sheet form-L-xlink), bilayer PDCM (non-crosslinked predicate collagen membrane in spongy form-Ctrl), or negative control (Sham) and compared with positive control (unoperated). Animals were euthanized after 4-, 8-, or 12-weeks of healing to evaluate soft tissue regeneration and remodeling through histomorphometric analyses. H-xlink membranes presented delayed healing with a poorly developed epithelial layer (analogous to the sham group) across time points. Relative to Ctrl at 8 and 12 weeks, defects treated with H-xlink presented no difference in semiquantitative scores ( P > 0.05), while L-xlink exhibited greater healing ( P = 0.042, P = 0.043, at 8 and 12 weeks, respectively). Relative to positive control, L-xlink exhibited similar healing at 8 weeks and greater healing at 12 weeks ( P = 0.037) with a well-developed epithelial layer. Overall, groups treated with L-xlink presented with greater healing relative to the positive control after 12 weeks of healing and may serve as an alternative to autologous grafts for intraoral soft tissue regeneration.

Effects on dentin nanomechanical properties, cell viability and dentin wettability of a novel plant-derived biomodification monomer.

OBJECTIVES: To evaluate the effects of dentin biomodification agents (Proanthocyanidin (PAC), Cardol (CD) and Cardol-methacrylate (CDMA) on dentin hydrophilicity by contact angle measurement, viability of dental pulp stem cells (DPSCs) and nanomechanical properties of the hybrid layer (HL). METHODS: CDMA monomer was synthesized from cardol through methacrylic acid esterification. Human extracted third molars were used for all experiments. For nanomechanical tests, specimens were divided in four groups according to the primer solutions (CD, CDMA, PAC and control) were applied before adhesive and composite coating. Nanomechanical properties of the HL were analyzed by nanoindentation test using a Berkovich probe in a nanoindenter. Wettability test was performed on dentin surfaces after 1 min biomodification and measured by contact angle analysis. Cytotoxicity was assessed by a MTT assay with DPSCs after 48 and 72 h. Data were analyzed with Student's t test or Two-way ANOVA and Tukey HSD test (p < 0.05). RESULTS: CD and CDMA solutions achieved greater hydrophobicity and increased the water-surface contact angles when compared to PAC and control groups (p < 0.05). PAC group showed a greater reduction of elastic modulus in nanoindentation experiments when compared to CD and CDMA groups (p < 0.05) after 4 months of aging. CD inhibited cell proliferation compared to all further materials (p < 0.05), whilst CDMA and PAC indicated no cell cytotoxicity to human DPSCs. SIGNIFICANCE: Cardol-methacrylate provided significantly higher hydrophobicity to dentin and demonstrated remarkable potential as collagen crosslinking, attaining the lowest decrease of HL's mechanical properties. Furthermore, such monomer did not affect pulp cytotoxicity, thereby highlighting promising feasibility for clinical applications.

Odontogenic Cutaneous Fistula: A Zombie Diagnosis.

BACKGROUND: Odontogenic cutaneous fistula (OCF) is a pathologic communication between the cutaneous surface of the face and oral cavity. Majority of oral cutaneous fistulas are reported to arise from chronic dental infection. Delay in treatment may result in chronic tissue injury as well as cosmetic deformities. Lesions are often misdiagnosed, leading to delayed management. Misdiagnosis may be the result of the variability of clinical morphological presentation and location of lesions compounded by the lack of knowledge that these lesions can have dental etiology. It is estimated that half of patients with OCF undergo multiple dermatologic surgical operations, antibiotic regimens, and other excisions and biopsies before a correct diagnosis is made. Herein, we present a systematic review to detail cases of odontogenic cutaneous lesions that had been previously misdiagnosed or managed inappropriately. In addition, we include a case report from our own institution. The aims are to demonstrate various presentations of OCF, increase awareness of plastic surgeons and oral maxillofacial surgeons to this pathological condition, and reinforce the importance of prompt diagnosis and treatment. METHODS: The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A literature search was conducted in PubMed, Web of Science, and Cochrane databases from January 1, 2013 to July 24, 2023. The following search terms were utilized: "odontogenic cutaneous fistula" OR "odontogenic cutaneous sinus." RESULTS: Twenty-three articles published between 2013 and 2023 were included in this review. In addition, we report a case from our own institution. A total of 28 cases were included in the review. CONCLUSIONS: Diagnosis of OCF is challenging for numerous reasons. Misdiagnosis can lead to multiple trials of antibiotics and surgical procedures as well as reoccurrence of the lesion. Cases summarized highlight the importance of communication between oral maxillofacial surgery, plastic surgery, other medical subspecialists, and dentists in the evaluation of patients with head and neck lesions. Physicians should consider dental etiology in the differential diagnosis of orofacial skin lesions, even if teeth appear normal on oral examination.

Translational Experimental Basis of Indirect Adenosine Receptor Agonist Stimulation for Bone Regeneration: A Review.

Bone regeneration remains a significant clinical challenge, often necessitating surgical approaches when healing bone defects and fracture nonunions. Within this context, the modulation of adenosine signaling pathways has emerged as a promising therapeutic option, encouraging osteoblast activation and tempering osteoclast differentiation. A literature review of the PubMed database with relevant keywords was conducted. The search criteria involved in vitro or in vivo models, with clear methodological descriptions. Only studies that included the use of indirect adenosine agonists, looking at the effects of bone regeneration, were considered relevant according to the eligibility criteria. A total of 29 articles were identified which met the inclusion and exclusion criteria, and they were reviewed to highlight the preclinical translation of adenosine agonists. While preclinical studies demonstrate the therapeutic potential of adenosine signaling in bone regeneration, its clinical application remains unrealized, underscoring the need for further clinical trials. To date, only large, preclinical animal models using indirect adenosine agonists have been successful in stimulating bone regeneration. The adenosine receptors (A1, A2A, A2B, and A3) stimulate various pathways, inducing different cellular responses. Specifically, indirect adenosine agonists act to increase the extracellular concentration of adenosine, subsequently agonizing the respective adenosine receptors. The agonism of each receptor is dependent on its expression on the cell surface, the extracellular concentration of adenosine, and its affinity for adenosine. This comprehensive review analyzed the multitude of indirect agonists currently being studied preclinically for bone regeneration, discussing the mechanisms of each agonist, their cellular responses in vitro, and their effects on bone formation in vivo.

Characterization of a hydrothermally aged experimental alumina-toughened zirconia composite.

OBJECTIVES: To assess the effects of different aging protocols on chemical, physical, and mechanical properties of an experimental ATZ composite compared to a zirconia. METHODS: Disc-shaped specimens were obtained through uniaxial pressing of commercial powders (Tosoh), ATZ comprised of 80%ZrO2/20%Al2O3 (TZ-3YS20AB) and 3Y-TZP (3Y-SBE). The specimens of each material were divided into different groups according to the aging protocol: immediate, autoclave aging and hydrothermal reactor aging. The aging protocols were performed at 134 ºC for 20 h at 2.2 bar. Crystalline evaluations were performed using X-Ray Diffraction. The nanoindentation tests measured the elastic modulus (Em) and hardness (H). Biaxial flexural strength was performed, and Weibull statistics were used to determine the characteristic strength and Weibull modulus. The probability of survival was also determined. The Em and H data were analyzed by one-way ANOVA and Tukey test. RESULTS: Diffractograms revealed the presence of monoclinic phase in both materials after aging. The hydrothermal reactor decreased the Em for ATZ compared to its immediate condition; and the H for both ATZ and 3Y-TZP regarding their immediate and autoclave aging conditions, respectively. The aging protocols significantly increased the characteristic strength for ATZ, while decreased for 3Y-TZP. No difference regarding Weibull modulus was observed, except for 3Y-TZP aged in reactor. For missions of up to 500 MPa, both materials presented a high probability of survival (>99 %) irrespective of aging condition. SIGNIFICANCE: The synthesized ATZ composite exhibited greater physical and microstructural stability compared to 3Y-TZP, supporting potential application of the experimental material for long-span reconstructive applications.

Elucidating the Benefit of Perforated vs Non-Perforated Membranes in Guided Bone Regeneration: An in Vivo Histologic Evaluation and Histomorphometric Analysis.

BACKGROUND: Non-perforated Polytetrafluoroethylene (PTFE) membranes are effectively utilized in guided bone regeneration (GBR) but may hinder cell migration due to limited interaction with the periosteum. This study compared bone regeneration using occlusive or perforated membranes combined with acellular collagen sponge (ACS) and recombinant human bone morphogenic protein-2 (rhBMP-2) in a canine mandibular model. MATERIAL AND METHODS: Male beagle dogs (n=3) received two mandibular defects each to compare ACS/rhBMP-2 with experimental (perforated group) and control (non-perforated group) membranes (n=3 defects/group). Tissue healing was assessed histomorphologically, histomorphometrically and through volumetric reconstruction using microcomputed tomography. RESULTS: The perforated group showed increased bone formation and reduced soft tissue formation compared to the non-perforated group. For the primary outcome, histomorphometric analysis revealed significantly greater total regenerated bone in the perforated group (67.08 ± 6.86%) relative to the nonperforated group (25.18 ± 22.44%) (p = 0.036). Perforated membranes had less soft tissue infiltration (32.91 ± 6.86%) compared to non-perforated membranes (74.82 ± 22.44%) (p = 0.036). CONCLUSION: The increased permeability of membranes in the perforated group potentially enabled periosteal precursor cells greater accessibility to rhBMP-2. The availability may have accelerated their differentiation into mature bone-forming cells, contributing to the stimulation of new bone production, relative to the non-perforated group.

Nasopharyngoscopic Evaluation of Velopharyngeal Closure During Speech.

Definitive oronasal separation through closure of the velopharyngeal (VP) sphincter is necessary for the development of normal speech and feeding. Individuals with velopharyngeal incompetence or insufficiency often exhibit hypernasal speech, poor speech intelligibility, and nasal regurgitation. Assessment of VP sphincter function using nasopharyngoscopy is a key element in identifying VP dysfunction. A foundational understanding of normal anatomy and physiology of the velopharyngeal mechanism is paramount to successful diagnosis. This includes recognition of 4 distinct VP sphincter closure patterns: coronal, sagittal, circular, and circular with Passavant's ridge. In this study, the authors showcase 2 patients with velopharyngeal competence who presented to an ear, nose, and throat clinic for nasopharyngoscopic evaluation. This study sought to demonstrate the use of nasopharyngoscopy to recognize velopharyngeal closure patterns and discuss how they may influence the surgical management of VP dysfunction.

What a Ratchet! A Gripping Case Report of an Entrapped Finger with an Unyielding Wrench.

Finger entrapment with rings or ring-like objects is an uncommon possible hand emergency. In cases in which noncutting removal is ineffective, ring cutters or dental drills with carbide or diamond burs have been successfully used. However, objects composed of hard metallic alloys, such as lug nuts or wrenches, are often resistant to such equipment. In these instances, larger diameter metal cutting burrs or rasps may be more advantageous. Due to their increased size and cutting power, these tools are better suited to handle the toughness of hard metals. In this case report, we present the effective and efficient removal of a stainless steel wrench from an entrapped digit using a helicoidal rasp. Availability of this instrument within orthopedic departments may prevent the delays often described in the treatment of finger entrapment when traditional cutting equipment fails.

An Evaluation of Autologous Fat Injection as a Treatment for Velopharyngeal Insufficiency: A Review and Integrated Data Analysis.

BACKGROUND: Velopharyngeal insufficiency (VPI) is a condition characterized by incomplete separation of the oral and nasal cavities during speech production, thereby leading to speech abnormalities and audible nasal emissions. Subsequently, this adversely impacts communication and potentially interpersonal social interactions. Autologous fat grafting (AFG) to the velopharynx, a minimally invasive technique, aims to improve oronasal separation by providing bulk and advancing the posterior pharyngeal wall toward the soft palate. Despite its potential, the relative novelty of AFG in treating VPI has resulted in reporting of inconsistent indications, varied surgical techniques, and mixed outcomes across existing literature. METHODS: This systemic review examined the evidence of AFG for VPI treatment over the past decade (2013-2023). A thorough search across five electronic databases yielded 233 studies, with 20 meeting the inclusion criteria (e.g., utilized fat injection as their selected VPI treatment, conducted study in human subjects, did not perform additional surgical procedure at time of fat injection). Selected studies encompassed patient and surgical intervention characteristics, perceptual speech assessment (PSA) scores, gap sizes, nasalance measurements, and complications. RESULTS: The majority of patients had a prior cleft palate diagnosis (78.2%), in which nasoendoscopy was the prevalent method for visualizing the velopharyngeal port defect. Fat harvesting predominantly occurred from the abdomen (64.3%), with an average injection volume of 6.3 mL across studies. PSA and subjective gap size scores were consistently higher preoperatively than postoperatively. PSA score analysis from seven studies revealed significant and sustained improvements postoperatively. Gap size score analysis from four studies demonstrated similar preoperative and postoperative differences. Complications were reported in 17 studies, yielding a 2.7% summative complication rate among 594 cases. CONCLUSIONS: Autologous fat grafting has emerged as a minimally invasive, safe, and effective treatment for mild to moderate VPI. However, challenges remain because of variability in patient selection criteria, diagnostic modalities, and outcome measurements. This review underscores the need for randomized control trials to directly compare AFG with standard-of-care surgical interventions, providing more conclusive evidence of its clinical efficacy.

Application of 3D Printing in Cleft Lip and Palate Repair.

This manuscript reviews the transformative impact of 3-dimensional (3D) printing technologies in the treatment and management of cleft lip and palate (CLP), highlighting its application across presurgical planning, surgical training, implantable scaffolds, and postoperative care. By integrating patient-specific data through computer-aided design and manufacturing, 3D printing offers tailored solutions that improve surgical outcomes, reduce operation times, and enhance patient care. The review synthesizes current research findings, technical advancements, and clinical applications, illustrating the potential of 3D printing to revolutionize CLP treatment. Further, it discusses the future directions of combining 3D printing with other innovative technologies like artificial intelligence, 4D printing, and in situ bioprinting for more comprehensive care strategies. This paper underscores the necessity for multidisciplinary collaboration and further research to overcome existing challenges and fully utilize the capabilities of 3D printing in CLP repair.

A rhPDGF-BB/bovine type I collagen/ß-TCP mixture for the treatment of critically sized non-union tibial defects: An in vivo study in rabbits.

Non-union during healing of bone fractures affects up to ~5% of patients worldwide. Given the success of recombinant human platelet-derived growth factor-B chain homodimer (rhPDGF-BB) in promoting angiogenesis and bone fusion in the hindfoot and ankle, rhPDGF-BB combined with bovine type I collagen/ß-TCP matrix (AIBG) could serve as a viable alternative to autografts in the treatment of non-unions. Defects (~2 mm gaps) were surgically induced in tibiae of skeletally mature New Zealand white rabbits. Animals were allocated to one of four groups-(1) negative control (empty defect, healing for 8 weeks), (2 and 3) acute treatment with AIBG (healing for 4 or 8 weeks), and (4) chronic treatment with AIBG (injection 4 weeks post defect creation and then healing for 8 weeks). Bone formation was analyzed qualitatively and semi-quantitatively through histology. Samples were imaged using dual-energy X-ray absorptiometry and computed tomography for defect visualization and volumetric reconstruction, respectively. Delayed healing or non-healing was observed in the negative control group, whereas defects treated with AIBG in an acute setting yielded bone formation as early as 4 weeks with bone growth appearing discontinuous. At 8 weeks (acute setting), substantial remodeling was observed with higher degrees of bone organization characterized by appositional bone growth. The chronic healing, experimental, group yielded bone formation and remodeling, with no indication of non-union after treatment with AIBG. Furthermore, bone growth in the chronic healing group was accompanied by an increased presence of osteons, osteonal canals, and interstitial lamellae. Qualitatively and semiquantitatively, chronic application of AI facilitated complete bridging of the induced non-union defects, while untreated defects or defects treated acutely with AIBG demonstrated a lack of complete bridging at 8 weeks.

3D printed ß-tricalcium phosphate versus synthetic bone mineral scaffolds: A comparative in vitro study of biocompatibility.

BACKGROUND: ß-tricalcium phosphate (ß-TCP) has been successfully utilized as a 3D printed ceramic scaffold in the repair of non-healing bone defects; however, it requires the addition of growth factors to augment its regenerative capacity. Synthetic bone mineral (SBM) is a novel and extrudable carbonate hydroxyapatite with ionic substitutions known to facilitate bone healing. However, its efficacy as a 3D printed scaffold for hard tissue defect repair has not been explored. OBJECTIVE: To evaluate the biocompatibility and cell viability of human osteoprecursor (hOP) cells seeded on 3D printed SBM scaffolds via in vitro analysis. METHODS: SBM and ß-TCP scaffolds were fabricated via 3D printing and sintered at various temperatures. Scaffolds were then subject to qualitative cytotoxicity testing and cell proliferation experiments utilizing (hOP) cells. RESULTS: SBM scaffolds sintered at lower temperatures (600 °C and 700 °C) induced greater levels of acute cellular stress. At higher sintering temperatures (1100 °C), SBM scaffolds showed inferior cellular viability relative to ß-TCP scaffolds sintered to the same temperature (1100 °C). However, qualitative analysis suggested that ß-TCP presented no evidence of morphological change, while SBM 1100 °C showed few instances of acute cellular stress. CONCLUSION: Results demonstrate SBM may be a promising alternative to ß-TCP for potential applications in bone tissue engineering.

Sustained Release of Salicylic Acid for Halting Peri-Implantitis Progression in Healthy and Hyperglycemic Systemic Conditions: A Gottingen Minipig Model.

To develop a peri-implantitis model in a Gottingen minipig and evaluate the effect of local application of salicylic acid poly(anhydride-ester) (SAPAE) on peri-implantitis progression in healthy, metabolic syndrome (MS), and type-2 diabetes mellitus (T2DM) subjects. Eighteen animals were allocated to three groups: (i) control, (ii) MS (diet for obesity induction), and (iii) T2DM (diet plus streptozotocin for T2DM induction). Maxillary and mandible premolars and first molar were extracted. After 3 months of healing, four implants per side were placed in both jaws of each animal. After 2 months, peri-implantitis was induced by plaque formation using silk ligatures. SAPAE polymer was mixed with mineral oil (3.75 mg/µL) and topically applied biweekly for up to 60 days to halt peri-implantitis progression. Periodontal probing was used to assess pocket depth over time, followed by histomorphologic analysis of harvested samples. The adopted protocol resulted in the onset of peri-implantitis, with healthy minipigs taking twice as long to reach the same level of probing depth relative to MS and T2DM subjects (∼3.0 mm), irrespective of jaw. In a qualitative analysis, SAPAE therapy revealed decreased levels of inflammation in the normoglycemic, MS, and T2DM groups. SAPAE application around implants significantly reduced the progression of peri-implantitis after ∼15 days of therapy, with ∼30% lower probing depth for all systemic conditions and similar rates of probing depth increase per week between the control and SAPAE groups. MS and T2DM conditions presented a faster progression of the peri-implant pocket depth. SAPAE treatment reduced peri-implantitis progression in healthy, MS, and T2DM groups.

Nonthermal Atmospheric Pressure Plasma Treatment of Endosteal Implants for Osseointegration and Antimicrobial Efficacy: A Comprehensive Review.

The energy state of endosteal implants is dependent on the material, manufacturing technique, cleaning procedure, sterilization method, and surgical manipulation. An implant surface carrying a positive charge renders hydrophilic properties, thereby facilitating the absorption of vital plasma proteins crucial for osteogenic interactions. Techniques to control the surface charge involve processes like oxidation, chemical and topographical adjustments as well as the application of nonthermal plasma (NTP) treatment. NTP at atmospheric pressure and at room temperature can induce chemical and/or physical reactions that enhance wettability through surface energy changes. NTP has thus been used to modify the oxide layer of endosteal implants that interface with adjacent tissue cells and proteins. Results have indicated that if applied prior to implantation, NTP strengthens the interaction with surrounding hard tissue structures during the critical phases of early healing, thereby promoting rapid bone formation. Also, during this time period, NTP has been found to result in enhanced biomechanical fixation. As such, the application of NTP may serve as a practical and reliable method to improve healing outcomes. This review aims to provide an in-depth exploration of the parameters to be considered in the application of NTP on endosteal implants. In addition, the short- and long-term effects of NTP on osseointegration are addressed, as well as recent advances in the utilization of NTP in the treatment of periodontal disease.

Development of ZTA (80% Al2O3/20% ZrO2) pre-sintered blocks for milling in CAD/CAM systems.

The present work aims to develop a production method of pre-sintered zirconia-toughened-alumina (ZTA) composite blocks for machining in a computer-aided design and computer-aided manufacturing (CAD-CAM) system. The ZTA composite comprised of 80% Al2O3 and 20% ZrO2 was synthesized, uniaxially and isostatically pressed to generate machinable CAD-CAM blocks. Fourteen green-body blocks were prepared and pre-sintered at 1000 °C. After cooling and holder gluing, a stereolithography (STL) file was designed and uploaded to manufacture disk-shaped specimens projected to comply with ISO 6872:2015. Seventy specimens were produced through machining of the blocks, samples were sintered at 1600 °C and two-sided polished. Half of the samples were subjected to accelerated autoclave hydrothermal aging (20h at 134 °C and 2.2 bar). Immediate and aged samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Optical and mechanical properties were assessed by reflectance tests and by biaxial flexural strength test, Vickers indentation and fracture toughness, respectively. Samples produced by machining presented high density and smooth surfaces at SEM evaluation with few microstructural defects. XRD evaluation depicted characteristic peaks of alpha alumina and tetragonal zirconia and autoclave aging had no effect on the crystalline spectra of the composite. Optical and mechanical evaluations demonstrated a high masking ability for the composite and a characteristic strength of 464 MPa and Weibull modulus of 17, with no significant alterations after aging. The milled composite exhibited a hardness of 17.61 GPa and fracture toughness of 5.63 MPa m1/2, which remained unaltered after aging. The synthesis of ZTA blocks for CAD-CAM was successful and allowed for the milling of disk-shaped specimens using the grinding method of the CAD-CAM system. ZTA composite properties were unaffected by hydrothermal autoclave aging and present a promising alternative for the manufacture of infrastructures of fixed dental prostheses.

Three-Dimensional Printing Methods for Bioceramic-Based Scaffold Fabrication for Craniomaxillofacial Bone Tissue Engineering.

Three-dimensional printing (3DP) technology has revolutionized the field of the use of bioceramics for maxillofacial and periodontal applications, offering unprecedented control over the shape, size, and structure of bioceramic implants. In addition, bioceramics have become attractive materials for these applications due to their biocompatibility, biostability, and favorable mechanical properties. However, despite their advantages, bioceramic implants are still associated with inferior biological performance issues after implantation, such as slow osseointegration, inadequate tissue response, and an increased risk of implant failure. To address these challenges, researchers have been developing strategies to improve the biological performance of 3D-printed bioceramic implants. The purpose of this review is to provide an overview of 3DP techniques and strategies for bioceramic materials designed for bone regeneration. The review also addresses the use and incorporation of active biomolecules in 3D-printed bioceramic constructs to stimulate bone regeneration. By controlling the surface roughness and chemical composition of the implant, the construct can be tailored to promote osseointegration and reduce the risk of adverse tissue reactions. Additionally, growth factors, such as bone morphogenic proteins (rhBMP-2) and pharmacologic agent (dipyridamole), can be incorporated to promote the growth of new bone tissue. Incorporating porosity into bioceramic constructs can improve bone tissue formation and the overall biological response of the implant. As such, employing surface modification, combining with other materials, and incorporating the 3DP workflow can lead to better patient healing outcomes.

Direct inkjet writing of polylactic acid/ß-tricalcium phosphate composites for bone tissue regeneration: A proof-of-concept study.

There is an ever-evolving need of customized, anatomic-specific grafting materials for bone regeneration. More specifically, biocompatible and osteoconductive materials, that may be configured dynamically to fit and fill defects, through the application of an external stimulus. The objective of this study was to establish a basis for the development of direct inkjet writing (DIW)-based shape memory polymer-ceramic composites for bone tissue regeneration applications and to establish material behavior under thermomechanical loading. Polymer-ceramic (polylactic acid [PLA]/ß-tricalcium phosphate [ß-TCP]) colloidal gels were prepared of different w/w ratios (90/10, 80/20, 70/30, 60/40, and 50/50) through polymer dissolution in acetone (15% w/v). Cytocompatibility was analyzed through Presto Blue assays. Rheological properties of the colloidal gels were measured to determine shear-thinning capabilities. Gels were then extruded through a custom-built DIW printer. Space filling constructs of the gels were printed and subjected to thermomechanical characterization to measure shape fixity (Rf) and shape recovery (Rr) ratios through five successive shape memory cycles. The polymer-ceramic composite gels exhibited shear-thinning capabilities for extrusion through a nozzle for DIW. A significant increase in cellular viability was observed with the addition of ß-TCP particles within the polymer matrix relative to pure PLA. Shape memory effect in the printed constructs was repeatable up to 4 cycles followed by permanent deformation. While further research on scaffold macro-/micro-geometries, and engineered porosities are warranted, this proof-of-concept study suggested suitability of this polymer-ceramic material and the DIW 3D printing workflow for the production of customized, patient specific constructs for bone tissue engineering.

Osseointegration of implant surfaces in metabolic syndrome and type-2 diabetes mellitus.

This in vivo study evaluated the bone healing response around endosteal implants with varying surface topography/chemistry in a preclinical, large transitional model induced with metabolic syndrome (MS) and type-2 diabetes mellitus (T2DM). Fifteen Göttingen minipigs were randomly distributed into two groups: (i) control (normal diet, n = 5) and (ii) O/MS (cafeteria diet for obesity induction, n = 10). Following obesity induction, five minipigs from the obese/metabolic syndrome (O/MS) group were further allocated, randomly, into the third experimental group: (iii) T2DM (cafeteria diet + streptozotocin). Implants with different surface topography/chemistry: (i) dual acid-etched (DAE) and (ii) nano-hydroxyapatite coating over the DAE surface (NANO), were placed into the right ilium of the subjects and allowed to heal for 4 weeks. Histomorphometric evaluation of bone-to-implant contact (%BIC) and bone area fraction occupancy (%BAFO) within implant threads were performed using histomicrographs. Implants with NANO surface presented significantly higher %BIC (~26%) and %BAFO (~35%) relative to implants with DAE surface (%BIC = ~14% and %BAFO = ~28%, p < .025). Data as a function of systemic condition presented significantly higher %BIC (~28%) and %BAFO (~42%) in the control group compared with the metabolically compromised groups (O/MS: %BIC = 14.35% and %BAFO = 26.24%, p < .021; T2DM: %BIC = 17.91% and %BAFO = 26.12%, p < .021) with no significant difference between O/MS and T2DM (p > .05). Statistical evaluation considering both factors demonstrated significantly higher %BIC and %BAFO for the NANO surface relative to DAE implant, independent of systemic condition (p < .05). The gain increase of %BIC and %BAFO for the NANO compared with DAE was more pronounced in O/MS and T2DM subjects. Osseointegration parameters were significantly reduced in metabolically compromised subjects compared with healthy subjects. Nanostructured hydroxyapatite-coated surfaces improved osseointegration relative to DAE, regardless of systemic condition.

The Aesthetic Surgery Education and Research Foundation (ASERF): A 30-Year Retrospective Analysis.

Federal government research grants provide limited funding to plastic surgeon-scientists, with reconstructive research taking precedence over aesthetic research. The Aesthetic Surgery Education and Research Foundation (ASERF) is a nonprofit, 501(c)(3) organization that seeks to support innovative, diverse research endeavors within aesthetic surgery. A total of 130 ASERF-funded studies and 32 non-funded applications from 1992 to 2022 were reviewed. Kruskal Wallis, Fisher's exact, and chi-squared tests were utilized to assess the potential relationship between self-identified gender, practice setting, geographical location, and study type with individual grant amounts and grant funding decision. Although significant differences were observed between male and female grant recipient h-indices (P < .05), there were no differences in the amount of funding they received (P > .05). Grant amounts were also consistent between study types as well as principal investigator practice settings and geographical locations (P > .05). The subanalysis revealed that the practice setting of the primary investigator (PI) was the only variable to exhibit a significant association with the decision to award funding (P < .05). Further, of the 61 applicants between 2017 and 2022, only 2 PIs self-identified as female. ASERF serves as an excellent funding source for global aesthetic surgery. To promote further research diversification, increased emphasis should be placed on recruiting applicants from outside academia and those who identify as female or gender nonbinary.