Characteristics of Particles and Debris Released after Implantoplasty: A Comparative Study

The work was supported by Graduate Periodontic, College of Dentistry, OUHSC and Department of Occupational and Environmental Health, Hudson College of Public Health, OUHSC. The work was also supported by the Spanish Government and the Ministry of Science and Innovation of Spain by research projects RTI2018-098075-B-C21 and RTI2018-098075-B-C22 (co-funded by the European Regional Development Fund (ERDF), a way to build Europe).Titanium particles embedded on peri-implant tissues are associated with a variety of detrimental effects. Given that the characteristics of these detached fragments (size, concentration, etc.) dictate the potential cytotoxicity and biological repercussions exerted, it is of paramount importance to investigate the properties of these debris. This study compares the characteristics of particles released among different implant systems (Group A: Straumann, Group B: BioHorizons and Group C: Zimmer) during implantoplasty. A novel experimental system was utilized for measuring and collecting particles generated from implantoplasty. A scanning mobility particle sizer, aerodynamic particle sizer, nano micro-orifice uniform deposit impactor, and scanning electron microscope were used to collect and analyze the particles by size. The chemical composition of the particles was analyzed by highly sensitive microanalysis, microstructures by scanning electron microscope and the mechanical properties by nanoindentation equipment. Particles released by implantoplasty showed bimodal size distributions, with the majority of particles in the ultrafine size range (<100 nm) for all groups. Statistical analysis indicated a significant difference among all implant systems in terms of the particle number size distribution (p < 0.0001), with the highest concentration in Group B and lowest in Group C, in both fine and ultrafine modes. Significant differences among all groups (p < 0.0001) were also observed for the other two metrics, with the highest concentration of particle mass and surface area in Group B and lowest in Group C, in both fine and ultrafine modes. For coarse particles (>1 m), no significant difference was detected among groups in terms of particle number or mass, but a significantly smaller surface area was found in Group A as compared to Group B (p = 0.02) and Group C (p = 0.005). The 1 first minute of procedures had a higher number concentration compared to the second and third minutes. SEM-EDS analysis showed different morphologies for various implant systems. These results can be explained by the differences in the chemical composition and microstructures of the different dental implants. Group B is softer than Groups A and C due to the laser treatment in the neck producing an increase of the grain size. The hardest implants were those of Group C due to the cold-strained titanium alloy, and consequently they displayed lower release than Groups A and B. Implantoplasty was associated with debris particle release, with the majority of particles at nanometric dimensions. BioHorizons implants released more particles compared to Straumann and Zimmer. Due to the widespread use of implantoplasty, it is of key importance to understand the characteristics of the generated debris. This is the first study to detect, quantify and analyze the debris/particles released from dental implants during implantoplasty including the full range of particle sizes, including both micro- and nano-scales.Graduate Periodontic, College of Dentistry, OUHSC and Department of Occupational and Environmental Health, Hudson College of Public Health, OUHSCSpanish Government RTI2018-098075-B-C21 and RTI2018-098075-B-C22 ( European Regional Development Fund (ERDF)

Periostin increases migration and proliferation of human periodontal ligament fibroblasts challenged by tumor necrosis factor ‐α and Porphyromonas gingivalis lipopolysaccharides

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106894/1/jre12120.pd

Preliminary insight into the periostin leverage during periodontal tissue healing

BackgroundTissue repair and regeneration is assisted by the efficient coordination of cell and extracellular matrix interactions mediated by matricellular molecules such as periostin. Given its high expression around the teeth, the periodontal organ represents an ideal system to capture the protein dynamics during wound healing.MethodsAn observational prospective case–control study was designed to characterize periostin changes over time after periodontal surgery in tissue, oral fluids and serum by histological, protein and mRNA analyses.ResultsHistological analysis showed lower periostin with a diffuse local distribution pattern in disease patients. Levels of periostin in gingival crevicular fluid (GCF) increased over time for both groups, more noticeably in the periodontitis subjects. A transient and subtle change in circulating periostin levels was also noticed. The mRNA periostin levels contrasted with the protein levels and may indicate the underlying post‐transcriptional regulatory process during chronic inflammation. Levels of known periodontal disease biomarkers such as IL‐β, IL1‐α, TNF‐α, MIP‐1α and CRP served as tissue stability markers and complemented the clinical parameters recorded.ConclusionThe transient local increase in GCF periostin after eliminating the local etiology in periodontally affected sites suggests its importance in the maturation and stability of the connective tissue. The decreasing levels observed as the tissue healed highlight its spatial/temporal significance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113755/1/jcpe12432.pd

Preclinical Evidence for the Use of Oral Mesenchymal Stem Cell-Derived Extracellular Vesicles in Bone Regenerative Therapy: A Systematic Review

Tissue engineering is a relatively recent research area aimed at developing artificial tissues that can restore, maintain, or even improve the anatomical and/or functional integrity of injured tissues. Otolaryngology, as a leading surgical specialty in head and neck surgery, is a candidate for the use of these advanced therapies and medicinal products developed. Nevertheless, a knowledge-based analysis of both areas together is still needed. The dataset was retrieved from the Web of Science database from 1900 to 2020. SciMAT software was used to perform the science mapping analysis and the data for the biomedical translation identification was obtained from the iCite platform. Regarding the analysis of the cognitive structure, we find consolidated research lines, such as the generation of cartilage for use as a graft in reconstructive surgery, reconstruction of microtia, or the closure of perforations of the tympanic membrane. This last research area occupies the most relevant clinical translation with the rest of the areas presenting a lower translational level. In conclusion, Tissue engineering is still in an early translational stage in otolaryngology, otology being the field where most advances have been achieved. Therefore, although otolaryngologists should play an active role in translational research in tissue engineering, greater multidisciplinary efforts are required to promote and encourage the translation of potential clinical applications of tissue engineering for routine clinical useUniversidad Peruana de Ciencias Aplicadas, Lima, Perú (UPC-ExPost-2023-2)The PECART-0027-2020 (Consejería de Salud y Familias, Junta de Andalucía, Spain)ProyExcel_00875 (Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Junta de Andalucía, Spain)Research Group #CTS-1028 (MP-M and PG-M, Junta de Andalucía, Spain

Expression of Musashi-1 During Osteogenic Differentiation of Oral MSC: An In Vitro Study

Supplementary materials can be found at https://www.mdpi.com/1422-0067/20/9/2171/s1Background: Musashi-1 (MSI1) is a negative regulator of mesenchymal stromal cell (MSC) differentiation which in turn favors cell proliferation. However, little is known about its expression by MSC from the oral cavity and in the context of osteogenic differentiation. Aim: The aim of this study was to analyze the expression of MSI1 in the context of osteogenic differentiation of MSC derived from the oral cavity. Material/methods: For this in vitro study, MSC were isolated from six different origins of the oral cavity. They were extensively characterized in terms of proliferative and clonogenicity potential, expression of stemness genes (MYC, NANOG, POU5F1, and SOX2), expression of surface markers (CD73, CD90, CD105, CD14, CD31, CD34, and CD45) and adipo-, chondro- and osteogenic differentiation potential. Then, osteogenic differentiation was induced and the expression of MSI1 mRNA and other relevant markers of osteogenic differentiation, including RUNX2 and Periostin, were also evaluated. Results: Cell populations from the alveolar bone (pristine or previously grafted with xenograft), dental follicle, dental germ, dental pulp, and periodontal ligament were obtained. The analysis of proliferative and clonogenicity potential, expression of the stemness genes, expression of surface markers, and differentiation potential showed similar characteristics to those of previously published MSC from the umbilical cord. Under osteogenic differentiation conditions, all MSC populations formed calcium deposits and expressed higher SPARC. Over time, the expression of MSI1 followed different patterns for the different MSC populations. It was not significantly different than the expression of RUNX2. In contrast, the expression of MSI1 and POSTN and RUNX2 were statistically different in most MSC populations. Conclusion: In the current study, a similar expression pattern of MSI1 and RUNX2 during in vitro osteogenic differentiation was identified.The authors of this investigation were partially supported by Research Groups #CTS-138 (F.O.) and #CTS-1028 (M.P.-M., P.G.-M.) (Junta de Andalucía, Spain), a grant from MIS Implant Technologies Ltd. (M.P.-M., D.A.-G., P.G.-M.), the Youth Employment Initiative (YEI) from the European Commission (R.S.-U.), and the Instituto de Salud Carlos III, Spain (www.isciii.es) and Fondo Europeo de Desarrollo Regional (FEDER, from the European Union), through the research grants PI15/00794 and CPII15/00032 (P.A)

Colloidal systems in bone regeneration. Is the size important

Poly lactic-co-glycolic acid (PLGA) is one of the most widely used synthetic polymers for development of delivery systems for drugs and therapeutic biomolecules. Its properties and versatility make it a reference polymer in the manufacturing of nano and microparticles to encapsulate and deliver a wide variety of hydrophobic and hydrophilic molecules, including biomolecules such as proteins or nucleic acids that must be released in a controlled way [1]. Delivery of growth factors such as bone morphogenetic proteins, and specially BMP-2, is an attractive therapeutic strategy for bone tissue engineering. However, their administration is problematic due to their short biological half-lives, localized action and rapid clearance. Consequently, its clinical use requires high doses far exceeding its physiological concentration which implies possible side effects and high costs. These barriers might be overcome by developing new delivery systems which allow a better control of the release rate in order to achieve the desired concentrations in specific site and time [2]. With this aim, in this preliminary study we have synthesized PLGA particles with different diameters, from nano (200 nm) to micro scale (12.5 μm) via double emulsion procedure, in order to study the influence of size in the release profile of lysozyme, which has been selected as an appropriate model for BMP2. A physico-chemical characterization of the particles was done, followed by a complete study on the encapsulation efficiency, cumulative protein release and bioactivity of the released enzyme with and without co-encapsulated bovine serum albumin, a protective biomolecule that can prevent protein instability during emulsification process. Additionally, fluorescently labeled lysozyme was used to study the protein distribution and the influence of particle size on the in vitro cellular uptake.Universidad de Málaga. Campus Internacional de Andalucía Tec

Inferior alveolar nerve trajectory, mental foramen location and incidence of mental nerve anterior loop

Background: Injury of the inferior alveolar nerve (IAN) is a serious intraoperative complication that may occur during routine surgical procedures, such as dental implant placement or extraction of impacted teeth. Thus, the purpose of this study was to analyze the trajectory of the mandibular canal (MC), the location of the mental foramen (MF) and the presence and extension of an anterior loop of the mental nerve (AL). Study Design: In this cross-sectional study, a total of 348 CBCTs were analyzed. Distances from MC to the surface of the basal, medial and lateral cortical of the mandible were measured at the level of the second molar, first molar and second premolar. Location of the MF relative to the apices of the premolars, as well as incidence and anterior extent of the AL were also determined. Results: Significant and clinically relevant correlations were found between the position of the MC in women, which was located more caudal (r=-0.219, p=0.007; r=-0.276, p<0.001; right and left, respectively) and lateral (r=-0.274, p=0.001; r=-0.285, p<0.001; right and left, respectively), particularly at the level of the premolars. Additionally, the presence (r=-0.181, p=0.001; r=-0.163, p=0.002; right and left, respectively) and anterior extension (r=-0.180, p=0.009; r=-0.285, p=0.05; right and left, respectively) of the AL was found to be inversely correlated with the age of the patient. Conclusions: This analysis of a Caucasian population has found that the older the patient, the lower the incidence of the loop and the shorter its anterior extension. Key words:Cone-beam computed tomography, mandibular nerve, mental foramen

Generalized Aggressive Periodontitis as a Risk Factor for Dental Implant Failure: A Systematic Review and Metaâ Analysis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141920/1/jper1398-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141920/2/jper1398.pd

Biologic Agents for Periodontal Regeneration and Implant Site Development

The advancement of molecular mediators or biologic agents has increased tremendously during the last decade in periodontology and dental implantology. Implant site development and reconstruction of the lost periodontium represent main fields in which these molecular mediators have been employed and investigated. Different growth factors trigger different reactions in the tissues of the periodontium at various cellular levels. Proliferation, migration, and differentiation constitute the main target areas of these molecular mediators. It was the purpose of this comprehensive review to describe the origin and rationale, evidence, and the most current understanding of the following biologic agents: Recombinant Human Platelet-Derived Growth Factor-BB (rhPDGF-BB), Enamel Matrix Derivate (EMD), Platelet-Rich Plasma (PRP) and Platelet-Rich Fibrin (PRF), Recombinant Human Fibroblast Growth Factor-2 (rhFGF-2), Bone Morphogenic Proteins (BMPs, BMP-2 and BMP-7), Teriparatide PTH, and Growth Differential Factor-5 (GDF-5).This paper was partially supported by the University of Michigan Periodontal Graduate Student Research Fund

The Influence of History of Severe Periodontitis on Estimated Long-Term Marginal Bone Loss around Implants Restored with Fixed Segmented Full-Arch Rehabilitation

The authors of this manuscript are partially supported by Research Groups #CTS-138, #CTS-176 and #CTS-1028 (Junta de Andalucía, Spain).The aim of this study was to analyze the long-term marginal bone level (MBL) of implants supporting fixed full-arch restoration in patients who had previously lost their dentition due to severe periodontitis. This retrospective study included 35 patients in whom 342 implants with internal tapered conical connections were placed. MBL was analyzed radiographically over time and a long-term estimation of MBL was calculated. A mixed linear model with abutment height, graft, diameter and location (maxilla/mandible) as factors and gender, age, implant length and prosthetic variables as covariates was used to evaluate the influence on MBL. MBL in these patients showed an estimator of predictions at 4108 days after loading of −0.307 mm, SE = 0.042. Only 0.15% of implants were radiographically affected with MBL of 3 mm or more. The mixed linear model results showed a main effect of the type of opposing dentition, gender, implant diameter, and abutment height. Particularly, an abutment height of 1 mm had associated larger MBL than the remaining heights. Thus, it can be concluded that dental implants restored with fixed segmented full-arch rehabilitation in patients with a history of severe periodontal disease do not suffer important marginal bone loss if some specific factors are considered, mainly the use of long transmucosal abutments (≥2 mm).Junta de Andalucía CTS-138, CTS-176, CTS-102