**11. Storage, distribution and quality control of tissue**

At the end of any processing mode, the procedures should be documented in a specific file. This file is used to contain all the documentation related to the process, including records of the participant team, inputs used, documents evidencing sterility of instruments and other records that are part of the quality control program and that provide subsidies for traceability of the processes. This stage is imperative in the legislation and recommended by the Standards and Quality Control Manuals.

The tissue stock can be kept both frozen and at room temperature (lyophilized) following the same standards used by the global tissue banks and associations. Other processing methods have been investigated with the purpose of reducing the costs related to banking and maintenance. The glycerolization of bone tissue is presented as a processing methodology able to maintain the viability of the matrix and to prevent bacterial growth, besides enabling storage at room temperature (Giovani, 2006).

Until the transplantation occurs, all the processed tissues should be submitted to rigid quality assurance criteria. It is necessary to have an evaluation of all the data pertaining to the donor, results of exams, maintenance and control of equipment, material and instruments used in all the phases of each procedure. Management software can be used to record all the stages, allowing the fast retrieval of information such as the particulars of the donor, lot, shelf life, exams and status of the tissue (analysis, released, excluded, used) making it easier to trace each graft processed and made available, especially in the presence of evidence of an adverse effect and implementation of corrective and preventive actions.

For a lot of grafts under analysis to be released for use, the qualified technical professional from the Tissue Bank must analyze the results of all the exams performed: NAT or PCR serology for HIV, HBC and HCV, General Culture, Anaerobic Culture, Fungal Culture, Anatomopathological Exam and radiology reports. These exam reports are ultimately evaluated and released by the Qualified Clinical Professional of the service.

Besides exams, it is necessary to consider an evaluation of the printed records of temperature during the banking period. The service should have equipment that detects temperature oscillations even at a distance (satellite monitoring system).

Moreover, the installation of buzzers at strategic points of the hospital as well as Co2 backups ensures the reliability of the system.

After the release of each lot, there should also be a final inspection of each tissue, besides the substitution of tags of tissues under analysis by replaced. The banking logistics of the tissues in the ultra-low temperature (ULT) freezers considers the tissue type and search agility.

Services that execute rigorous quality control use annotation systems featuring checklists with double checking and consent.

All the data pertaining to the donor and to the lot, in compliance with the legislation, should be kept in single folders and stored in specific files of the musculoskeletal tissue bank for a minimum period of 25 years.

A serum bank with samples of donor plasma should also be made available by the musculoskeletal tissue bank in case of the need for counterproof exams.

At the end of any processing mode, the procedures should be documented in a specific file. This file is used to contain all the documentation related to the process, including records of the participant team, inputs used, documents evidencing sterility of instruments and other records that are part of the quality control program and that provide subsidies for traceability of the processes. This stage is imperative in the legislation and recommended by

The tissue stock can be kept both frozen and at room temperature (lyophilized) following the same standards used by the global tissue banks and associations. Other processing methods have been investigated with the purpose of reducing the costs related to banking and maintenance. The glycerolization of bone tissue is presented as a processing methodology able to maintain the viability of the matrix and to prevent bacterial growth,

Until the transplantation occurs, all the processed tissues should be submitted to rigid quality assurance criteria. It is necessary to have an evaluation of all the data pertaining to the donor, results of exams, maintenance and control of equipment, material and instruments used in all the phases of each procedure. Management software can be used to record all the stages, allowing the fast retrieval of information such as the particulars of the donor, lot, shelf life, exams and status of the tissue (analysis, released, excluded, used) making it easier to trace each graft processed and made available, especially in the presence of evidence of an adverse effect and implementation of corrective and preventive actions.

For a lot of grafts under analysis to be released for use, the qualified technical professional from the Tissue Bank must analyze the results of all the exams performed: NAT or PCR serology for HIV, HBC and HCV, General Culture, Anaerobic Culture, Fungal Culture, Anatomopathological Exam and radiology reports. These exam reports are ultimately

Besides exams, it is necessary to consider an evaluation of the printed records of temperature during the banking period. The service should have equipment that detects

Moreover, the installation of buzzers at strategic points of the hospital as well as Co2

After the release of each lot, there should also be a final inspection of each tissue, besides the substitution of tags of tissues under analysis by replaced. The banking logistics of the tissues in the ultra-low temperature (ULT) freezers considers the tissue type and search agility.

Services that execute rigorous quality control use annotation systems featuring checklists

All the data pertaining to the donor and to the lot, in compliance with the legislation, should be kept in single folders and stored in specific files of the musculoskeletal tissue bank for a

A serum bank with samples of donor plasma should also be made available by the

evaluated and released by the Qualified Clinical Professional of the service.

temperature oscillations even at a distance (satellite monitoring system).

musculoskeletal tissue bank in case of the need for counterproof exams.

backups ensures the reliability of the system.

with double checking and consent.

minimum period of 25 years.

**11. Storage, distribution and quality control of tissue** 

besides enabling storage at room temperature (Giovani, 2006).

the Standards and Quality Control Manuals.

As soon as the quality criteria have been evaluated and approved, the tissues are made available for use.

The tissues are distributed to the various specialties (Hip, Knee, Shoulder, Tumors and Dentistry) according to the availability of and requests for grafts.

The transplanter (physician or dentist) places the order for the tissue through a discussion of cases and by sending a specific form. The tissue reservation takes into account the demand for each type of transplant, waiting list and stock. The waiting list for transplantations performed within the Unified Health System - SUS complies with the prevailing legislation and today is organized and managed by the musculoskeletal tissue banks themselves, observing an order by date of inclusion. Urgent cases appointed by the medical team, such as malignant tumors and situations with a risk of severe complications, are communicated to the musculoskeletal tissue bank through an Emergency Form, for immediate response.

In dentistry, transplants have evolved differently and their distribution features some particularities that will be described further on.

#### **12. Global data on tissue transplantation activities in Brazil**

Today it can be seen that tissue transplantations in general are on the rise. Events such as officialization in the legislation and the creation of public promotion policies corroborate this evolution. Considering bone transplants alone, 30x growth has been observed in the last 5 years (Brazilian Transplantation Register, 2010), a fact motivated by the start of large-scale distribution of tissues for dental surgery. Although statistics show the number of tissues to be growing, the quantity of donors is still a concern. The vast majority of donors in Brazil are still for the removal of perfused solid organs (heart, kidney, liver, etc. A minority (6% on an average) accept the donation of musculoskeletal tissues. Of these, just 8% on average, become effective donors and the rest are discarded due to the presence of exclusion criteria such as infections, blood transfusion, and inadequate profile (**Graph 1**).

Graph 1. Reasons for refusals of bone donors between 2006-2010. (Source: File BTME-HC-USP)

Cryopreserved Musculoskeletal Tissue Bank in Dentistry: State of the Art and Perspectives 57

One of the factors most closely related to the indication of bone reconstructions in dentistry

The resorption of the alveolar edge is a chronic, progressive, irreversible and cumulative alteration. This condition, observed in the toothless individual, becomes faster in the first six months after exodontias or dental extractions. Once the function of providing support to the teeth has been lost, the alveolar process tends to undergo resorption due to disuse (Mecall & Rosenfeld, 1991). And this resorption can be exacerbated by local factors (traumatism, infections and pathologies), systemic factors (osteopenia, osteoporosis, osteomalacia, endocrine and nutritional alterations), systemic health problems, prosthetic treatments and

Projections by the Brazilian Institute of Geography and Statistics (IBGE) show that the elderly population in Brazil is set to increase considerably in future years. Life expectancy in 2020 is estimated at 71.2 years (men) and 74.7 years (women) and will represent 13% of the population (IBGE, 2011). Data from the Epidemiological Survey indicate the elderly age bracket as having the highest rates of edentulism and of prosthesis use for prolonged

The previous use not only of total prostheses but also of removable partial prostheses is identified as a predisposing factor of tissue resorption (odds ratio = 2.4), and the flaccid tissue from the edge is related to the severity of resorption (odds ratio = 2.4). (Watzek, 1996,

In this context, it is noted that the majority of atrophic edentulous cases (total or partial) has increasingly resorted to the adoption of dental implants and for this reason, bone grafts

Frozen homologous bone tissue is biocompatible and can be used successfully in treatments that require maxillary sinus lifting. Its use favors bone neoformation, integration, and absence of inflammatory infiltrate as well as an increase in the percentage of bone volume (Stacchi et al, 2008). In the long term, it is possible to observe the formation of viable and mature bone tissue, providing adequate reconstruction techniques are adopted. (Contar et

Some studies in the dental area have evaluated the efficacy of the use of allografts through an analysis of the biomechanics of implants placed in the grafting zone. This is possible through a resonance frequency analysis (RFA) and removal torque (RT) analysis. The results show that there is no difference in stability between implants installed with autogenous and allogeneic grafts. (Ribeiro, 2009) It is also possible to evaluate the osseointegration process through an evaluation of the neoformed bone volume. Lima (2010) studied homologous

appear as an option of biomaterial used in pre-prosthetic surgery (Galea, 2005).

Table 2. Factors related to the bone loss process (Source: Fonseca & Davis, 1995)

are maxillary and mandibular resorptions due to lack of the dental element.

 Frequency; Direction; Quantity. *Prosthetic Factors:*

> Type of prosthesis base; Shape and type of teeth.

others (Fonseca & Davis, 1995; Gassen et al, 2008)

periods. (Ministério da Saúde, 2003)

Xie et al, 1997)

al, 2009)
