Aesthetic and functional restoration of the dental arch continuity in difficult cases of impacted teeth within the frontal segment.

Impacted teeth are a fairly common defect with the incidence ranging from 2.9 to 13.7%. Evaluation of the efficacy and safety of various treatment modalities in patients with impacted teeth within the frontal segment of the maxilla. The retrospective evaluation covered treatment outcomes in 81 patients with impacted teeth within the aesthetic segment. The subjects were divided into 3 groups. Patients with the impacted tooth uncovered and orthodontically repositioned in the arch were assigned to group 1. Group 2 consisted of patients with the impacted tooth qualified for extraction and the gap augmented and restored with an implant. Group 3 included subjects, who underwent en-bloc autotransplantation of the impacted tooth. In 38 group 1 subjects 47 teeth were uncovered with a mean efficacy of 58.1% (96.3% and 70% in patients below 18 yoa and adults, respectively). The excellent aesthetic treatment outcome was obtained in 75% and good in 25% of patients. In group 2 twenty-six adult subjects were treated with 100% efficacy. In 65.4% of patients, augmentation with a bone block was performed and in the remaining 34.6%, implantation and augmentation with bone granulate. In 88.3% subjects a satisfying treatment outcome was obtained. In group 3 eighteen teeth in a block were grafted with the efficacy of 88.9%. Excellent aesthetics was obtained in 56.25% of cases and good in 31.25%. Orthodontic repositioning of the impacted teeth in the arch in adult patients bears the risk of failure. Surgical treatment modalities in impacted teeth are effective and provide high aesthetics of the treatment outcome improved by prior orthodontic treatment of the concomitant malocclusion and augmentation of the vertical bone atrophy before implantation.

Effect of gamma rays and accelerated electron beam on medullary lipids decomposition: influence of dose and irradiation temperature.

Ionizing radiation sterilization of non-defatted bone grafts has been found to deteriorate their quality and biocompatibility due to induction of lipid peroxidation products toxic for osteoblast-like cells. Therefore, the purpose of our study was to evaluate the effect of two types of ionizing radiation-gamma rays (G) or accelerated electron beam (EB) applied with two doses at different temperature conditions on hydrocarbons production, resulting from decomposition of palmitic and oleic acids-most abundant fatty acids in medullary lipids. Bone marrow samples isolated from femoral shafts of 6 male donors (aged 46-67 years) were irradiated with G or EB with doses of 25 or 35 kGy at different temperature conditions (ambient or deep freezing temperature). Fresh-frozen, non-irradiated samples served as control. Marrow lipids were extracted with n-hexane (Soxhlet's method), hydrocarbons fraction isolated on Florisil column chromatography, separated by gas chromatography and detected by mass spectrometry. Irradiation of bone marrow with sterilization doses of ionizing radiation (G and EB) was found to induce lipid radiolysis as measured by resulting hydrocarbons production. The effect was dose-dependent, whereas no marked influence of radiation type was observed. In contrast, irradiation temperature had a profound effect on lipids decomposition which was partially prevented while irradiation was performed in deep frozen state. Defatting of bone grafts prior to ionizing radiation sterilization seems essential for their biocompatibility, whereas irradiation in a deep-frozen state might compromise the effectiveness of sterilization and needs further studies.

Work-related problems faced by coordinators of organ, cell, and tissue transplantations in Poland and possible ways of ameliorating them.

In recent years in Poland, the numbers of reported potential cadaveric donors of organs, tissues, and cells, and the numbers of transplantations being carried out seem to be low in the context of the size of the country population and the presumed consent legal principle which rules transplantations. This research project was carried out on 109 Polish transplant coordinators by means of a questionnaire created specifically for this study. The goal of the project was to detect problems specific to transplant coordinators working in Poland which, when properly addressed, might improve the efficacy of transplantation network within the Polish health care system. The results suggest that Polish transplant coordinators face a variety of issues in their work. It appears that the most important interventions which could improve working conditions for in this population and-as a result-also improve the efficacy of transplantation network in Poland could include: (1) a variety of training programs for transplant coordinators; (2) a social campaign promoting transplantations and spreading awareness of the transplantation-related legislation; and (3) introduction of changes in the regulations pertaining to medical professions in Poland.

The urgent need to achieve an optimal strategic stock of human allogeneic skin graft materials in case of a mass disaster in Poland.

A burn is a sudden injury which immediate or long-term consequences may be life-threatening for the patient. A mass disaster event may involve large numbers of severely burned patients. Patients of this type typically have a limited area of healthy, unburned skin from which an autologous split thickness skin graft could be collected. In a clinical situation of this type, it is necessary to use a particular skin substitute. Non-viable allogeneic human skin graft materials might be considered as the most suitable skin substitutes in the treatment of such patients. At present, Poland does not have a sufficient supply of human allogeneic skin graft materials to meet the needs arising from a sudden and unforeseen mass disaster. This study involved an analysis of selected mass disasters. From this an estimate was made from a verified casualty profile of the necessary minimum stock of human allogeneic skin graft materials. An insufficient amount of skin results from an inadequate number of skin donors, which in turn results from the current tissue donation system. Therefore, a proposal has been made for the organizational, legal and systemic changes required to improve the situation in Polish transplantology, with particular emphasis on skin donation. In order to achieve a strategic stock of human skin grafts, a tissue collecting transplantation team should be organized. The rights and obligations of the non-physician transplant team member should be extended. Proposals have been made for awareness campaigns (adverts, posters etc.) and educational schemes (educational video, lectures during transplant coordinator training, etc.). Finally, a proposal has been made for possible methods to deal with the logistic management of the allogeneic skin stock. The required, essential stock of human allogeneic skin in the event of a mass disaster has been estimated at 600,000 cm2.

Access of non-residents to transplantation of deceased donor organs: practices and strategies in the European setting.

The access of non-resident patients to the deceased donor waiting list (DDWL) poses different challenges. The European Committee on Organ Transplantation of the Council of Europe (CD-P-TO) has studied this phenomenon in the European setting. A questionnaire was circulated among the Council of Europe member states to inquire about the criteria applied for non-residents to access their DDWL. Information was compiled from 28 countries. Less than 1% of recipients of deceased donor organs were non-residents. Two countries never allow non-residents to access the DDWL, four allow access without restrictions and 22 only under specific conditions. Of those, most give access to non-resident patients already in their jurisdictions who are in a situation of vulnerability (urgent life-threatening conditions). In addition, patients may be given access: (i) after assessment by a specific committee (four countries); (ii) within the framework of official cooperation agreements (15 countries); and (iii) after patients have officially lived in the country for a minimum length of time (eight countries). The ethical and legal implications of these policies are discussed. Countries should collect accurate information about residency status of waitlisted patients. Transparent criteria for the access of non-residents to DDWL should be clearly defined at national level.

Impact of Porcine Pancreas Decellularization Conditions on the Quality of Obtained dECM.

Due to the limited number of organ donors, 3D printing of organs is a promising technique. Tissue engineering is increasingly using xenogeneic material for this purpose. This study was aimed at assessing the safety of decellularized porcine pancreas, together with the analysis of the risk of an undesirable immune response. We tested eight variants of the decellularization process. We determined the following impacts: rinsing agents (PBS/NH3·H2O), temperature conditions (4 °C/24 °C), and the grinding method of native material (ground/cut). To assess the quality of the extracellular matrix after the completed decellularization process, analyses of the following were performed: DNA concentration, fat content, microscopic evaluation, proteolysis, material cytotoxicity, and most importantly, the Triton X-100 content. Our analyses showed that we obtained a product with an extremely low detergent content with negligible residual DNA content. The obtained results confirmed the performed histological and immuno-fluorescence staining. Moreover, the TEM microscopic analysis proved that the correct collagen structure was preserved after the decellularization process. Based on the obtained results, we chose the most favorable variant in terms of quality and biology. The method we chose is an effective and safe method that gives a chance for the development of transplant and regenerative medicine.

Optimization of Novel Human Acellular Dermal Dressing Sterilization for Routine Use in Clinical Practice.

Gamma rays and electrons with kinetic energy up to 10 MeV are routinely used to sterilize biomaterials. To date, the effects of irradiation upon human acellular dermal matrices (hADMs) remain to be fully elucidated. The optimal irradiation dosage remains a critical parameter affecting the final product structure and, by extension, its therapeutic potential. ADM slides were prepared by various digestion methods. The influence of various doses of radiation sterilization using a high-energy electron beam on the structure of collagen, the formation of free radicals and immune responses to non-irradiated (native) and irradiated hADM was investigated. The study of the structure changes was carried out using the following methods: immunohistology, immunoblotting, and electron paramagnetic resonance (EPR) spectroscopy. It was shown that radiation sterilization did not change the architecture and three-dimensional structure of hADM; however, it significantly influenced the degradation of collagen fibers and induced the production of free radicals in a dose-dependent manner. More importantly, the observed effects did not disrupt the therapeutic potential of the new transplants. Therefore, radiation sterilization at a dose of 35kGy can ensure high sterility of the dressing while maintaining its therapeutic potential.

Professional burnout and its correlates in Polish donor transplant coordinators.

Job demands-resources (JD-R) model of professional burnout states that job demands predict the feeling of exhaustion, and lack of job resources-disengagement from work. This research project investigated professional burnout and it correlates, including sex, death anxiety, and relationship status in 108 Polish donor transplant coordinators involved in organ, tissue, and cell transplantations. This study employed the Polish version of the Oldenburg Burnout Inventory which follows the JD-R model, the Psychosocial Working Conditions Questionnaire-a Polish instrument based on the model of job stress proposed by Karasek-and the Polish version of the Fear of Death and Dying Questionnaire. The results were suggestive of average levels of job stress and burnout in the studied population, with men being more disengaged than women. Participants who were in relationship had significantly higher levels of exhaustion than those who were single. Exhaustion was positively correlated with years of working as a transplant coordinator but not with participants' age. Multiple negative correlations were detected between exhaustion/disengagement and different aspects of job control, social support, and well-being. Moreover, positive correlations between different components of fear of death and dying and exhaustion were detected. Our findings, linking fear of death and dying with some aspects of professional burnout in transplant coordinators, suggest that a pre-employment screening for the level of death anxiety in candidates for transplant coordinators could be useful as this job provides chronic exposure to mortality cues.

Correlates of professional burnout in a sample of employees of cell and tissue banks in Poland.

Job Demands-Resources model proposes that the development of burnout follows excessive job demands and lack of job resources. Job demands are predictive of feeling of exhaustion, and lack of job resources-disengagement from work. This pilot study investigated professional burnout and its correlates in employees of Polish cell and tissue banks, many of whom were involved in procurement and processing of tissues from deceased donors, as it was hypothesized that job burnout in this population might influence the effectiveness of cell and tissue transplantation network in our country. This study utilized the Polish version of the Oldenburg Burnout Inventory (OLBI), which measures the two dimensions of burnout (exhaustion and disengagement), and the Psychosocial Working Conditions Questionnaire (PWC), a Polish instrument used for monitoring psychosocial stress at work. The study sample consisted of 31 participants. Their average time of working in a cell and tissue bank was 13.20 years. Majority of the PWC scales and subscales scores fell in the Average range, and the OLBI results for the Disengagement and the Exhaustion scales were in the Average range. A number of correlations between the Exhaustion or Disengagement and the PWC scales and subscales were detected, majority of which fell in the Moderate range. In spite of the limited number of participants, the results of this pilot study are consistent with the burnout literature reports. Among the detected correlates of professional burnout, it is job-related support which seems to be the most important factor which may influence the efficacy of transplantation network in Poland.

Preparation of allogeneic bone for alveolar ridge augmentation.

Implant treatment is safe and predictable with sufficient amount and quality of bone tissue. In case of severely reduced bone tissue after a tooth was lost, augmentation of such tissue is necessary before implant embedment. Retrospective evaluation covered 380 alveolar ridge reconstructions. The study material consisted of human grafts prepared by the Department of Transplantology and Central Tissue Bank, Medical University of Warsaw. Presentation of laboratory procedures in the context of physical parameters of frozen, radiation sterilised, allogeneic corticocancellous material was presented. The preparation process makes it possible to obtain two types of bone material: granules and blocks. Women underwent 164 procedures with the use of bone granules and 61 augmentations with bone blocks. In case of men 122 packages of granules were used as well as 33 bone blocks. Based on the results an evaluation of usability of available allogeneic grafts was performed with reference to planned alveolar ridge augmentation procedures, which they were used for. 1. The opportunity to prepare allogeneic material of different textures allowed selection to meet augmentation requirements while providing biological safety. 2. Allogeneic granules should be used in multi-wall defects, such as a double, closed sinus lift and post-extraction socket augmentation. 3. Owing to their superior mechanical parameters, bone blocks were successfully used in extending the width and height of the alveolar ridge and in open sinus lifts with one-wall or two-wall defects and adequate location of the lamellar bone in a graft prevented substantial graft resorption.

Structural mechanical properties of radiation-sterilized human Bone-Tendon-Bone grafts preserved by different methods.

To avoid the risk of infectious disease transmission from donor to recipient, allografts should be terminally sterilized. In the previous paper (Kaminski et al. in Cell Tissue Bank 10:215-219, 2009) we presented the effect of various methods of preservation (deep fresh freezing, glycerolization, lyophilization), followed by irradiation with different doses of electron beam (EB), on material (intrinsic) mechanical properties of human patellar tendons cut out as for anterior cruciate ligament reconstruction, obtained in failure tensile test. As structural mechanical properties are equally important to predict the behaviour of the graft as a whole functional unit, the purpose of the present paper was to show the results for failure load and elongation, obtained in the same experiment. Paired Bone-Tendon-Bone grafts (BTB) were prepared from cadaveric human patella tendons with both patellar and tibial attachments. They were preserved by deep freezing, glycerolization or lyophilization and subsequently EB-irradiated with the doses of 25, 35, 50 or 100 kGy (fresh-frozen grafts) or a single dose of 35 kGy (glycerolized and lyophilized grafts). Each experimental (irradiated) group was provided with control (non-irradiated), donor-matched group. The specimens from all groups were subjected to mechanical failure tensile test with the use of Instron system in order to measure their structural properties (failure load and elongation). All lyophilized grafts were rehydrated before mechanical testing. In our study we did not observe significant deterioration of structural mechanical properties of BTB grafts processed by fresh-freezing and then terminal sterilized with growing doses of EB up to 100 kGy. In contrast, BTB grafts processed by glycerolization or lyophilization and irradiated with 35 kGy showed significant decrease of failure load. Obtained results suggest that deep-frozen irradiated grafts retain their initial mechanical properties to an extent which does not exclude their clinical application. However, biomechanical investigations constitute only the first step to evaluate the potential clinical usefulness of such allografts and further extensive in vivo studies are needed.

Two-stage closed sinus lift: a new surgical technique for maxillary sinus floor augmentation.

Bone tissue atrophy may constitute a relative contraindication for implantation. The methods used in reconstruction of the alveolar ridge within the lateral section of the maxilla have been well known but not perfect. Presentation of the two-stage, closed sinus lift technique as well as efficacy evaluation of reconstruction of the alveolar ridge in the maxilla within its vertical dimension with the use of this technique. The total procedure was performed in 26 out of 28 patients qualified for the study. The height of the alveolar ridge at the site of the planned implantation was no <3 mm, the width of the ridge was no <5 mm. During the treatment stage 1 the sinus lift was performed for the first time. The created hollow was filled with allogeneic granulate. After 3-6 months stage 2 was performed consisting in another sinus lift with simultaneous implantation. The treatment was completed with prosthetic restoration after 6 months of osteointegration. In 24 out of 26 cases stage 1 was completed with the average ridge height of 7.2 mm. In stage 2, simultaneously with the second sinus lift, 26 implants were placed and no cases of sinusitis were found. In the follow-up period none of the implants were lost. The presented method is efficient and combines the benefits of the open technique-allowing treatment in cases of larger reduction of the vertical dimension and the closed technique-as it does not require opening of the maxillary sinus.

Long-term outcomes of the use of allogeneic, radiation-sterilised bone blocks in reconstruction of the atrophied alveolar ridge in the maxilla and mandible.

Increasingly dental surgeons face the challenge of reconstruction of the height and/or thickness of the alveolar ridge as more and more patients wish to have permanent restoration of their dental defects based on intraosseous implants. Evaluation of human allogeneic bone tissue grafts in reconstruction of atrophied alveolar ridge as a pre-implantation procedure. The material comprised 21 patients aged 19-63, treated between 2009 and 2012 by the same surgeon. Restoration of bone tissue defects was performed with allogeneic, frozen, radiation-sterilised, corticocancellous blocks. The study included 26 grafting procedures with 7 procedures consisting in reconstruction of the alveolar ridge in the mandible and 19 in the maxilla. In all the cases the atrophied alveolar ridge was successfully reconstructed, which allowed placement of intraosseous implants in compliance with the initial treatment plan. After the treatment was completed the patients reported for follow-up annually. The average time of follow-up amounted to 39 months (28-50 months). None of the implants was lost during the follow-up period. There was one case of gingival recession causing aesthetics deterioration of the prosthetic restoration. In three cases the connector became unscrewed partially, which was corrected at the same visit. Frozen, radiation-sterilised, allogeneic bone blocks constitute good and durable bone-replacement material allowing effective and long-lasting reconstruction of the atrophied alveolar ridge to support durable, implant-based, prosthetic restoration.

Global maxillary ridge augmentation with frozen radiation-sterilised bone blocks followed by implant placement: a case report.

Due to atrophy of the tissue within the alveolar ridge, implantation must sometimes be preceded by bone regeneration. The use of allogeneic material allows the surgeon to prepare grafts of any shape and amount; therefore it is a good alternative to autograft reconstruction in patients with extensive atrophy of the alveolar ridge. The patient with maxillary anodontia showed insufficient width of the ridge along its entire length, which prevented implantation. Therefore, alveolar ridge reconstruction was planned. Four frozen, radiation-sterilised bone blocks processed in the Tissue Bank in Warsaw were used for reconstruction of the alveolar ridge. The blocks were grafted to the area of molars, premolars and lateral incisors bilaterally. Three months after surgery a normal union of transplants with the recipient site was achieved. Six implants were embedded and following the 6-month integration period a permanent prosthetic restoration was successfully performed. During a 38-month follow-up none of the implants were lost and the aesthetic or functional condition of the prosthetic restoration did not deteriorate. Frozen allogeneic radiation-sterilised bone blocks constitute good, efficient and safe material used in reconstruction of the alveolar ridge in extensive bone atrophy. This is only one of possible grafting materials for reconstruction of extremely atrophic alveolar ridge.

Allogeneic materials in complications associated with pre-implantation restoration of maxillary and mandibular alveolar processes. A four case report.

There are numerous types of bone replacement materials used to regenerate atrophic alveolar processes before the elective intraosseous implantation. Properties of these materials differ one from another, therefore the choice of material should be thoroughly analysed as well as its type and texture in regard of intraoral conditions and the objective to be achieved. The study involved reconstruction of atrophic alveolar processes with allogeneic bone following unsuccessful use of synthetic and animal materials. The procedure of bone regeneration was performed with frozen bone block (case 1) and allogeneic bone granulate (cases 2, 3, 4) radiation-sterilised with 35 kGy prepared by the Tissue Bank. In all of the presented cases after 3-month implant reorganisation optimal width of the process was obtained, which allowed implant embedment (case 1) or correct implant submergence in the osseous tissue, when implantation took place at the same time (case 2, 3, 4). Allogeneic bone material both, in the form of a block as well as granulate, seems to be an adequate alternative for other materials used in order to widen the bone of the alveolar process, particularly in difficult, complicated cases, where the first regeneration procedure was not successful.

Effect of gamma radiation and accelerated electron beam on stable paramagnetic centers induction in bone mineral: influence of dose, irradiation temperature and bone defatting.

Ionizing radiation has been found to induce stable defects in the crystalline lattice of bone mineral hydroxyapatite, defined as CO(2) (-) radical ions possessing spins. The purpose of our study was to evaluate CO(2) (-) radical ions induced in non-defatted or defatted human compact bone by gamma radiation (G) and accelerated electron beam (EB), applied with two doses at different temperatures. Moreover, the potential effect of free radical ion formation on mechanical parameters of compact bone, tested under compression in the previous studies, was evaluated. Bone rings from femoral shafts of six male donors (age 51 ± 3 years) were collected and assigned to sixteen experimental groups according to different processing methods (non-defatted or defatted), G and EB irradiation dose (25 or 35 kGy), and irradiation temperature [ambient temperature (AT) or dry ice (DI)]. Untreated group served as control. Following grinding under LN2 and lyophilization, CO(2) (-) radical ions in bone powder were measured by electron paramagnetic resonance spectrometry. We have found that irradiation of bone with G and EB induces formation of enormous amounts of CO(2) (-) radical ions, absent from native tissue. Free radical ion formation was dose-dependent when irradiation was performed at AT, and significantly lower in EB as compared to G-irradiated groups. In contrast, no marked effect of dose was observed when deep-frozen (DI) bone samples were irradiated with G or EB, and free radical ion numbers seemed to be slightly higher in EB-irradiated groups. Irradiation at AT induced much higher quantities of CO(2) (-) radical ions then on DI. That effect was more pronounced in G-irradiated bone specimens, probably due to longer exposure time. Similarly, bone defatting protective effect on free radical ion formation was found only in groups irradiated for several hours with gamma radiation at ambient temperature. Ambient irradiation temperature together with exposure time seem to be key parameters promoting CO(2) (-) radical ion formation in bone mineral and may mask the opposite effect of defatting and the possible effect of irradiation type. Significant weak negative correlations between CO(2) (-) radical ion number and some mechanical properties of compact bone rings (Young's modulus and ultimate stress) were found.

Three-layered osteodural plasty for severe anterior skull base and facial injuries. Report of eleven cases.

BACKGROUND AND PURPOSE: The upper cranial trauma of high force and wide area of application leads to fractures of calvaria, the skull base, and the viscerocranium. The aim of the study was to present eleven patients treated for severe anterior skull base and facial defects by means of three-layered osteodural plasty. MATERIALS AND METHODS: The operative tactics consisted of bicoronal incision, bifrontal craniotomy, closure of the dura mater damage with a pericranium, reconstruction of bone defects with autologous bone grafts and plasty with anteriorly pedicled pericranial flap on the supratrochlear and supraorbital vessels. RESULTS: During follow-up, which lasted 2-7 years, none of the patients developed any early or late postoperative complications. CONCLUSIONS: The three-layer osteodural plasty of severe anterior skull base injuries with the use of autologous bone grafts for the reconstruction of craniofacial skeleton resulted in a good final functional, morphological and aesthetic outcome in all patients.

Organ Procurement From Foreigners Who Died in Poland and Organ Transplantation to Foreigners.

The aim of the work was to present data concerning organ donation from and transplantation to foreigners in Poland. Data came from registries maintained by the Polish Transplant Coordinating Center POLTRANSPLANT, consisting of the national waiting list, deceased donor registry, transplant registry, and live donor registry. In Poland, the rules for organ and tissue procurement for transplantation from foreigners who died in Poland and the rules for transplanting organs to foreigners are adopted and applied. Before the outbreak of the war in Ukraine, "cross-border" cases of donations and transplants were rather sporadic. After the outbreak of the war, due to the mass influx of Ukrainian citizens, the situation changed, and the participation of foreigners (mostly Ukrainians) in transplantation procedures increased significantly and, in 2022, accounted for the total number of events: approximately 4% in the case of donation, slightly over 1% in the case of qualifications for transplantation and almost 2% in the number of transplantations performed. Despite this increase, the number of events is not high or critical and does not affect the efficiency of organ transplantation medicine in Poland.

Demand for Continuous and Long-Term Care in Transplant Recipients: Data From the Organ Transplantation Registry-Poltransplant Activity.

BACKGROUND: This study aimed to determine the number of recipients with active transplants under the care of transplant centers in 2022 and the current volume and needs for continuous and long-term care in this group of transplant recipients. Data came from the organ transplant registry, one of the registries maintained by the Polish Transplant Coordinating Center Poltransplant. We included recipients of individual organs who, on January 1, 2022, were living with an active transplant performed in previous years and recipients who received a transplant in 2022. The number of recipients under the care of transplant centers in 2022 was 20,994 (55% of all transplants performed in Poland since the beginning of activity in 1966).