Long-term stability of gingival margin and periodontal soft-tissue phenotype achieved after mucogingival therapy: A systematic review.

BACKGROUND: The aim of this systematic review was two-fold: (i) to evaluate the long-term (≥5 years) stability of the gingival margin position, keratinized tissue width (KTW) and gingival thickness (GT) in sites that underwent root coverage (RC) or gingival augmentation (GA); and (ii) to assess the influence of different local variables on the long-term stability of dental and gingival tissues. MATERIALS AND METHODS: Randomized controlled trials (RCTs) and non-RCTs reporting short-term (i.e., 6-12 months after baseline surgical intervention) and long-term (≥5 years) follow-up data after surgical treatment of adult patients presenting single or multiple mucogingival deformities, defined as sites presenting gingival recession defects (GRDs) and/or (KTW) deficiency (i.e., <2 mm), were considered eligible for inclusion. MEDLINE-PubMed, EMBASE and Cochrane Central Register of Controlled Trials databases were searched for articles published up to 15 May 2023. Mixed-effects multiple linear regression was used to assess the association between KTW, type of surgical procedure and time (i.e., independent variables) on the stability of the gingival margin in sites that received RC or GA therapy. RESULTS: Of the 2569 potentially eligible records, 41 (reporting 40 studies) met the eligibility criteria. Graphical estimates including data from all RC procedures found an upward trend in recession depth (RD) increase over time. Conversely, it was observed that in 63.63% of RC studies and in 59.32% of RC treatment arms KTW increased over time, particularly in sites treated with subepithelial connective tissue grafts (SCTGs). Conversely, sites that underwent GA procedures generally exhibited an overall reduction of KTW over time. However, sites treated with free gingival grafts (FGGs) showed a decrease in RD after 10 years of follow-up. Three main findings derived from the pooled estimates were identified: (i) Gingival margin stability was associated with the amount of KTW present during short-term assessment (i.e. the greater the KTW at 6-12 months after treatment, the more stable the gingival margin). (ii) The use of autogenous soft-tissue grafts was associated with lower RD increase over time. (iii) Treatment approaches that contribute to the three-dimensional enhancement of the gingival phenotype, as clearly demonstrated by FGG, were associated with gingival margin stability. CONCLUSIONS: The extent of apical migration of the gingival margin appears to be directly related to the amount of KTW and GT upon tissue maturation. Interventions involving the use of autogenous grafts, either SCTG or FGG, are associated with greater short-term KTW gain and lower RD increase over time.

Dimensional changes in free gingival grafts at implant sites in the reconstructed mandible: a retrospective study.

OBJECTIVE: To evaluate the dimensional changes in free gingival grafts (FGG) at implant sites in mandibular reconstruction patients. METHODS: Patients who received FGG 4 months after implant placement in the reconstructed mandible with no keratinized mucosa (KM) present were invited for re-examination after 36.7 ± 16.8 months (3.06 ± 1.4 years). Immediately after graft extraction (T0), graft width (GW), graft length (GL), graft thickness (GT), graft dimension (GD), and vertical bone height were documented. Re-examination (T1) included clinical examinations (GW, GL, GD, peri-implant probing depths, and modified Sulcus Bleeding Index), radiographic examination (marginal bone level), and medical chart review. RESULTS: Twenty patients and 62 implants (47 in fibula flaps and 15 in iliac flaps) were included. A significant decrease in GW (51.8%), GL (19.2%), and GD (60.2%), were found between T0 and T1 (p < .001). The univariate analysis showed that GW change was not significantly associated with reconstruction technique, baseline GL, baseline GT, baseline GD, implant location, or type of prosthesis. Implant survival rate of 100% was observed at follow-up. CONCLUSIONS: Within the limitations of the study, free gingival grafts at implant sites in the reconstructed mandible undergo dimensional change that result in a reduction of approximately 60% of the original graft dimension. Graft width decreased over 50%. CLINICAL RELEVANCE: FGG is the standard of care intervention for increasing the amount of KM around implants. This study was the first to evaluate the dimensional change in FGG at implant sites in mandibular reconstruction patients after a medium-term follow-up. CLINICAL TRIAL REGISTRATION: Clinical trial registration is not applicable as this study comprehends a retrospective analysis.

The influence of tobacco smoking on the outcomes achieved by root coverage procedures: An updated systematic review.

OBJECTIVE: This updated version of a systematic review (SR) originally published in 2009 evaluated the effect of smoking on the clinical outcomes achieved with root coverage (RC) procedures in the treatment of gingival recession (GR) defects. MATERIALS AND METHODS: This SR includes randomized controlled trials, controlled clinical trials, and case series with a minimum follow-up of 6 months. Eligible studies involved GR defects without interproximal tissue loss submitted to RC procedures, as well as outcome measures from smokers (i.e., those smoking 10 or more cigarettes per day at baseline) and nonsmokers, recorded separately. Three electronic databases were searched up to March 31, 2024. Random effects meta-analyses were conducted thoroughly. RESULTS: A total of 12 studies reporting on 181 smokers and 162 nonsmokers, submitted to different RC procedures, were included. Half of these trials were originally included in the 2009 SR, whereas the other half (six studies) were included in this update. Nonsmokers experienced greater reductions in GR and gains in clinical attachment level compared to smokers. Pooled estimates comparing smokers and nonsmokers who received coronally advanced flap (CAF) alone and subepithelial connective tissue graft (SCTG) + CAF showed that nonsmokers achieved greater mean root coverage (MRC) in both treatments. Significant differences in MRC of 10.85% (95% CI, 1.92 to 19.77) and 22.04 (95% CI, 14.25 to 29.83), favoring nonsmokers, were identified for CAF and SCTG + CAF, respectively. Similarly, nonsmokers treated with SCTG + CAF displayed superior number of sites exhibiting complete root coverage (CRF) when compared with smokers (risk ratio, 4.12; 95% CI, 1.73 to 9.80). CONCLUSIONS: Smoking negatively impacts the outcomes of RC procedures, particularly those achieved by SCTG-based procedures. CLINICAL SIGNIFICANCE: Smoking was linked to poorer RC outcomes. These outcomes highlight the critical need to integrate smoking cessation into periodontal treatment plans.

Wound healing dynamics, morbidity, and complications of palatal soft-tissue harvesting.

Palatal-tissue harvesting is a routinely performed procedure in periodontal and peri-implant plastic surgery. Over the years, several surgical approaches have been attempted with the aim of obtaining autogenous soft-tissue grafts while minimizing patient morbidity, which is considered the most common drawback of palatal harvesting. At the same time, treatment errors during the procedure may increase not only postoperative discomfort or pain but also the risk of developing other complications, such as injury to the greater palatine artery, prolonged bleeding, wound/flap sloughing, necrosis, infection, and inadequate graft size or quality. This chapter described treatment errors and complications of palatal harvesting techniques, together with approaches for reducing patient morbidity and accelerating donor site wound healing. The role of biologic agents, photobiomodulation therapy, local and systemic factors, and genes implicated in palatal wound healing are also discussed.

Histological and histomorphometric study of human palatal mucosa: Implications for connective tissue graft harvesting.

AIMS: To analyse the histological structure and histomorphometric characteristics of human hard palatal mucosa in order to determine the donor site of choice for connective tissue grafts from a histological point of view. MATERIALS AND METHODS: Palatal mucosa samples from six cadaver heads were harvested at four sites: incisal, premolar, molar and tuberosity. Histological and immunohistochemical techniques were performed, as was histomorphometric analysis. RESULTS: In the current study, we found that the density and size of cells were higher in the superficial papillary layer, whereas the thickness of the collagen bundles increased in the reticular layer. Excluding the epithelium, the mean percentage of lamina propria (LP) and submucosa (SM) was 37% and 63%, respectively (p < .001). LP thickness showed similar values in the incisal, premolar and molar regions, and a significantly greater thickness in tuberosity (p < .001). The thickness of SM increased from incisal to premolar and molar, disappearing in the tuberosity (p < .001). CONCLUSIONS: As dense connective tissue of LP is the tissue of choice for connective tissue grafts, the best donor site from a histological point of view is tuberosity because it is composed only of a thick LP without the presence of a loose submucosal layer.

Aesthetic evaluation of free gingival graft applied by partial de-epithelialization and free gingival graft applied by conventional method: a randomized controlled clinical study.

OBJECTIVE: The aim of this clinical study was to compare the partially de-epithelialized free gingival grafts (d-FGGs) with the conventional free gingival grafts (FGGs) aesthetically using photographic analysis and Visual Analogue Scale (VAS). MATERIALS AND METHODS: A total of 30 defects were treated in 15 patients with attached gingiva insufficiency. In the split-mouth study, d-FGGs were applied on one side (test group), while FGGs were applied on the contralateral side (control group). Results of clinical periodontal parameters were evaluated in 6-month follow-up, and aesthetic evaluation results were evaluated in 1-, 3-, and 6-month follow-ups. RESULTS: Among the periodontal clinical parameters examined, only the keratinized tissue (KT) width was found to be statistically significantly higher in the test group compared to the control group. In the photo analysis evaluation, the ΔE value at the 3rd month was statistically significantly higher in the test group. In VAS evaluation, there was no significant difference between the two groups in the time periods examined. CONCLUSION: Photo analysis is an objective, sensitive, reproducible, and safe method that can be used in dentistry and medicine by detecting the slightest changes and giving more detailed and superior results than visual evaluation. The d-FGG application could provide acceptable aesthetic results by providing an appearance compatible with the gingival contour and gingiva in the adjacent region in creating keratinized gingiva. CLINICAL RELEVANCE: While the free gingival graft has color differences with the recipient area, the deep-thelialized gingival graft has a compatible appearance with the recipient area. Partially, de-epithelialized free gingival graft is a method with acceptable aesthetic results. TRIAL REGISTRATION: U.S. National Institutes of Health Clinical Trials: NCT04970524.

The effects of vertically coronally advanced flap and free gingival graft techniques on shallow vestibule: a randomized comparative prospective trial.

OBJECTIVES: The present study aimed to compare the influence of vertically coronally advanced flap (V-CAF) and free gingival graft (FGG) techniques on shallow vestibule depth (VD). MATERIALS AND METHODS: Parallel-arm randomized clinical trial was conducted on 38 sites treated with either FGG or V-CAF. Periodontal variables (VD, recession depth and width, probing depth, clinical attachment level, keratinized tissue height (KTH), and tissue thickness (TT)), clinician- and patient-based subjective variables were assessed. RESULTS: All periodontal variables showed significant improvements in both groups at all follow-up intervals compared to baseline (p < 0.05). Both groups increased VD compared to baseline. RC and CRC were similar after treatment for both techniques. FGG provided a greater increase in KTH (p < 0.001) and VD (VD1, p = 0.02 and VD2, p < 0.001) while V-CAF exhibited more TT gain (p = 0.002). Except overall tissue appearance that was better in V-CAF (p < 0.001), no inter-group significant difference existed in patient-based variables. CONCLUSIONS: Both techniques were significantly effective in VD increasing. While both techniques were equally successful in RC, V-CAF provided higher TT gain and better tissue appearance. V-CAF can be chosen instead of FGG in the treatment of recessions with shallow VD. CLINICAL RELEVANCE: It can be recommended to prefer V-CAF instead of FGG in the treatment of shallow vestibule. TRIAL REGISTRATION NUMBER: NCT05777811 (clinicaltrials.gov).

Periodontal phenotype modification of complexes periodontal-orthodontic case scenarios: A clinical review on the applications of allogenous dermal matrix as an alternative to subepithelial connective tissue graft.

OBJECTIVES: The aim of this review is to address the potential applications of allogenous dermal matrix (ADM), as an alternative to subepithelial connective tissue graft (SCTG), in promoting periodontal phenotype modification (PPM) of challenging periodontal-orthodontic clinical scenarios. OVERVIEW: The rationale behind the need of changing thin to thick gingival tissues is associated to the superior and more stable treatment outcomes promoted by PPM therapy. PPM, via soft tissue grafting, leads to clinical and histological changes of the pre-established original genetic conditions of the gingiva. Although SCTG-based procedures are recognized as the "gold standard" for the treatment of sites requiring root coverage and gingival augmentation, ADM has been recognized as the most suitable alternative to SCTG, particularly in clinical scenarios where the use of autogenous grafts is not possible. Thus, ADM is considered an optimal option for the treatment of patients with a history (or in need) of orthodontic tooth movement, due its two-fold potential indication: (1) the promotion of periodontal soft tissue phenotype modification; and (2) its use, as a barrier membrane, in hard tissues augmentation procedures. CONCLUSIONS: ADM is a viable option for soft tissue augmentation, as well as for treatment approaches involving buccal bone gain. CLINICAL SIGNIFICANCE: Periodontal phenotype modification therapy, when applied in challenging periodontal-orthodontic clinical scenarios, promotes root coverage and prevents the onset and development clinical attachment loss.

Local Concentrations of TGF-ß1 and IGF-1 Appear Determinant in Regulating Bone Regeneration in Human Postextraction Tooth Sockets.

Healing after tooth extraction involves a series of reparative processes affecting both alveolar bone and soft tissues. The aim of the present study was to investigate whether activation of molecular signals during the healing process confers a regenerative advantage to the extraction socket soft tissue (ESsT) at 8 weeks of healing. Compared to subepithelial connective tissue graft (CTG), qRT-PCR analyses revealed a dramatic enrichment of the ESsT in osteogenic differentiation markers. However, ESsT and CTG shared characteristics of nonspecialized soft connective tissue by expressing comparable levels of genes encoding abundant extracellular matrix (ECM) proteins. Genes encoding the transforming growth factor-ß1 (TGF-ß1) and its receptors were strongly enriched in the CTG, whereas the transcript for the insulin-like growth factor-1 (IGF-1) showed significantly high and comparable expression in both tissues. Mechanical stimulation, by the means of cyclic strain or matrix stiffness applied to primary ESsT cells (ESsT-C) and CTG fibroblasts (CTG-F) extracted from the tissue samples, revealed that stress-induced TGF-ß1 not exceeding 2.3 ng/mL, as measured by ELISA, in combination with IGF-1 up to 2.5 ng/mL was able to induce the osteogenic potential of ESsT-Cs. However, stiff matrices (50 kPa), upregulating the TGF-ß1 expression up to 6.6 ng/mL, caused downregulation of osteogenic gene expression in the ESsT-Cs. In CTG-Fs, endogenous or stress-induced TGF-ß1 ≥ 4.6 ng/mL was likely responsible for the complete lack of osteogenesis. Treatment of ESsT-Cs with TGF-ß1 and IGF-1 proved that, at specific concentrations, the two growth factors exhibited either an inductive-synergistic or a suppressive activity, thus determining the osteogenic and mineralization potential of ESsT-Cs. Taken together, our data strongly warrant the clinical exploration of ESsT as a graft in augmentative procedures during dental implant placement surgeries.

Effectiveness of Plasma-Rich Fibrin and De-Epithelialized Free Gingival Graft in the Treatment of Gingival Recessions.

Introduction/Aim: Soft tissue dehiscences such as gingival recessions are a very common problem that we face in modern periodontics. This clinical study aimed to analyze the effectiveness of surgical procedures using a de-epithelialized gingival graft (DGG) combined with a coronally advanced flap and to evaluate the application of plasma-rich fibrin (PRF). Methods: The study included 40 teeth (20 patients) with Miller class I and II gingival recessions. Twenty recessions (20 patients) were treated utilizing the de-epithelialized gingival graft in combination with the coronally advanced flap, and on the opposite side of the jaw, the same number of recessions were treated utilizing plasma-rich fibrin combined with the coronally advanced flap. To evaluate tissue condition and the clinical parameters before and after the surgical procedure, the following parameters were used: the degree of epithelial attachment (DEA), the width of keratinized gingiva (WKG), and the vertical depth of recession (VDR). Results: based on the achieved results and the analysis of clinical parameters, a statistically significant reduction in the vertical depth of recession was proven in both groups, with very similar mean percentages of root coverage, with the difference being that the stability of the soft tissues of the treated region was more visible in the DGG. Conclusion: using modern surgical procedures allows the regeneration of not only the soft tissues but also deeper periodontal tissues.

Comparison between connective tissue graft and xenogeneic acellular dermal matrix to treat single gingival recession: A data reanalysis of randomized clinical trials.

OBJECTIVES: There are few studies comparing xenogeneic acellular dermal matrixes (XDMs) with connective tissue graft (CTG) to treat single gingival recession (GR). The present study involved a reanalysis of previous studies and comparison of CTG or XDM to treat single RT1/GR. MATERIALS AND METHODS: Fifty patients from three previous randomized clinical trials treated either by CTG (n = 25) or XDM (n = 25) were evaluated after 6-month. Clinical, patient-centered, and esthetic parameters were assessed. Pearson's correlation and regression analyses were also performed. RESULTS: Greater recession reduction (RecRed), percentage of root coverage (%RC), and complete root coverage (CRC) were observed in the CTG group (p ≤ 0.02). Gingival thickness (GT) and keratinized tissue width (KTW) gains were higher in the CTG group. The CTG group showed better esthetic at 6-month. Logistic analyses reported that GT([OR] = 1.6473 ) and papilla height (PH) (OR = 8.20) are predictors of CRC. GT*XDM interaction was a negative predictor of CRC (OR = 7.105-5 ). GT at baseline acted as a predictor of RecRed in both groups (p = 0.03). The XDM graft impacted RecRed and %RC negatively. Baseline PH was a predictor of %RC for both grafts. CONCLUSION: CTG was superior for treating RT1/GR, providing better root coverage outcomes and tissue gains over time. GT, PH, and graft type were classified as predictors of CRC. CLINICAL SIGNIFICANCE: CTG presented better outcomes to treat single RT1 gingival recession when compared to the XDM.

A Novel Volume-Stable Collagen Matrix Induces Changes in the Behavior of Primary Human Oral Fibroblasts, Periodontal Ligament, and Endothelial Cells.

The aim of the present study was to investigate the influence of a novel volume-stable collagen matrix (vCM) on early wound healing events including cellular migration and adhesion, protein adsorption and release, and the dynamics of the hemostatic system. For this purpose, we utilized transwell migration and crystal violet adhesion assays, ELISAs for quantification of adsorbed and released from the matrix growth factors, and qRT-PCR for quantification of gene expression in cells grown on the matrix. Our results demonstrated that primary human oral fibroblasts, periodontal ligament, and endothelial cells exhibited increased migration toward vCM compared to control cells that migrated in the absence of the matrix. Cellular adhesive properties on vCM were significantly increased compared to controls. Growth factors TGF-ß1, PDGF-BB, FGF-2, and GDF-5 were adsorbed on vCM with great efficiency and continuously delivered in the medium after an initial burst release within hours. We observed statistically significant upregulation of genes encoding the antifibrinolytic thrombomodulin, plasminogen activator inhibitor type 1, thrombospondin 1, and thromboplastin, as well as strong downregulation of genes encoding the profibrinolytic tissue plasminogen activator, urokinase-type plasminogen activator, its receptor, and the matrix metalloproteinase 14 in cells grown on vCM. As a general trend, the stimulatory effect of the vCM on the expression of antifibrinolytic genes was synergistically enhanced by TGF-ß1, PDGF-BB, or FGF-2, whereas the strong inhibitory effect of the vCM on the expression of profibrinolytic genes was reversed by PDGF-BB, FGF-2, or GDF-5. Taken together, our data strongly support the effect of the novel vCM on fibrin clot stabilization and coagulation/fibrinolysis equilibrium, thus facilitating progression to the next stages of the soft tissue healing process.

The Effect of Three Surgical Therapies to Increase Keratinized Mucosa Surrounding Dental Implants with Peri-Implantitis: A Pilot Study.

Background and Objectives: The purpose of this pilot study was to evaluate the clinical outcomes of three different methods for increasing the keratinized mucosa (KM) surrounding dental implants with peri-implantitis. Materials and methods: Twenty implant sites with peri-implantitis were divided into: (1) porcine collagen matrix (CM) group: seven implant sites; (2) apically positioned flap (APF) group: eight implant sites; and (3) free gingival graft (FGG) group: five implant sites. The KM width and clinical parameters (probing pocket depth (PPD) and bleeding on probing (BOP)) were measured at time points: before surgery (T0) and 30 (T1), 60 (T2), 90 (T3), and 180 (T4) days after surgery. Results: Regarding KM width, all the groups had significant differences for increasing horizontal and vertical KM width. The CM and FGG groups had greater KM than the APF group. There was a decrease in PPD in all three groups. APF and FGG showed significant differences in PPD at T1 and T2 compared to T0. Only the FGG group showed a significant difference in PPD at T3 and T4 compared with that at T0. BOP values were also reduced in all the groups at T1-T4 compared to T0. The APF and FGG groups showed a significant decrease in BOP. Conclusions: Three surgical therapies presented favorable results for increasing the KM surrounding implants. Compared with the FGG group, the CM showed similar results in increasing the KM around the dental implants with peri-implantitis.

Vitiligo surgery: A journey from tissues via cells to the stems!

Depigmented patches in vitiligo, a common dermatosis, cause a great psychological distress to the patients. Hence, apart from halting the disease process, the strategies to impart normal skin colour to these white patches carry an important role in the management of vitiligo. Surgical procedures are often required for stable vitiligo lesions not responding to medical therapies. It involves "shuffling" of melanocytes from the pigmented skin to the depigmented areas. During the last fifty years, the vitiligo surgery has evolved from tissue transplantation via cellular transplantation to reach a stage where the use of stem cells or immunomodulatory cells is contemplating. We would like to depict this wonderful journey of vitiligo surgery through this viewpoint.

Soft tissue-related complications and management around dental implants.

Implant installation for replacing missing teeth is a frequent treatment procedure with high long-term survival and success rates. However, the success of implant therapy may be jeopardized by several complications related to mistakes in treatment planning, surgical procedure, management of hard and soft tissues, and infections. Increasing evidence suggests that the stability of the soft tissues surrounding osseointegrated dental implants may substantially influence long-term clinical stability and esthetics. Therefore, when implant therapy is planned, the clinician must not only be able to perform the appropriate steps to maintain/create a stable soft tissue, but also needs to be aware of the potential sources for complications and possess the adequate knowledge for their appropriate management. The present paper provides an overview of the most important aspects related to the prevention and management of soft tissue-related complications in conjunction with implant therapy. The current literature indicates that the presence of an adequate width of keratinized attached mucosa around dental implants may lead to better soft and hard tissue stability, less plaque accumulation, limited soft tissue recession, and lower incidence of peri-implant mucositis. Proper implant positioning by carefully considering appropriate mesio-distal and bucco-lingual dimensions and implant angulation may prevent the loss of interdental soft tissues and development of soft tissue recessions. To optimize the width of keratinized attached mucosa, the appropriate soft tissue augmentation protocol should be selected for each particular indication. When the use of autogenous soft tissue grafts is planned, a thorough knowledge of the anatomical structures is mandatory in order to harvest soft tissue grafts of an appropriate quality and quantity and to avoid/minimize postoperative complications. Finally, the clinician needs to master the necessary steps in order to manage complications related to extensive bleeding and tissue necrosis that may occur in conjunction with soft tissue augmentation procedures.

High-resolution dental magnetic resonance imaging for planning palatal graft surgery-a clinical pilot study.

AIM: To evaluate whether high-resolution, non-contrast-enhanced dental magnetic resonance imaging (MRI) can be used for accurate determination of palatal masticatory mucosa thickness (PMMT) and to locate the greater palatal artery (GPA). MATERIALS AND METHODS: In five volunteers (four males, one female; mean age 30.2 ± 0.4 years), two independent raters measured PMMT by use of dental MRI in 180 positions. For comparison, clinical bone sounding was performed. The GPA was identified in time-of-flight (TOF) angiography and MSVAT-SPACE-prototype sequence. Intra- and inter-observer agreement for MRI measurements, agreement between MRI and bone sounding were analysed by intra-class correlation coefficient (ICC) and Cohen's kappa (κ). RESULTS: Reliability of dental MRI measurements was high (intra-observer-ICC 0.962; inter-observer ICC 0.959). Agreement of MRI measurements with bone sounding was moderate (ICC 0.744), and the GPA could be identified in 60% of measurement points using the TOF-angiography alone and in 85% with additional information of the MSVAT-SPACE. Good intra-observer agreement was observed for GPA identification (κ: 0.778). CONCLUSION: Palatal masticatory mucosa thickness measured by high-resolution, non-contrast enhanced dental MRI is comparable with that obtained by bone sounding. Dental MRI enables reliable, non-invasive and radiation-free planning of palatal tissue harvesting and can also be used for location of the GPA at 85% of measurement points, which might help reduce complications during surgery.

Risks of Using Sterilization by Gamma Radiation: The Other Side of the Coin.

The standard sterilization method for most medical devices over the past 40 years involves gamma irradiation. During sterilization, gamma rays efficiently eliminate microorganisms from the medical devices and tissue allografts, but also significantly change molecular structure of irradiated products, particularly fragile biologics such as cytokines, chemokines and growth factors. Accordingly, gamma radiation significantly alters biomechanical properties of bone, tendon, tracheal, skin, amnion tissue grafts and micronized amniotic membrane injectable products. Similarly, when polymer medical devices are sterilized by gamma radiation, their physico-chemical characteristics undergo modification significantly affecting their clinical use. Several animal studies demonstrated that consummation of irradiated food provoked genome instability raising serious concerns regarding oncogenic potential of irradiated consumables. These findings strongly suggest that new, long-term, prospective clinical studies should be conducted in near future to investigate whether irradiated food is safe for human consumption. In this review, we summarized current knowledge regarding molecular mechanisms responsible for deleterious effects of gamma radiation with focusing on its significance for food safety and biomechanical characteristics of medical devices, and tissue allografts, especially injectable biologics.

Advances of radiation sterilisation in tissue banking.

Under the auspices of the IAEA tissue banking programme on "Radiation Sterilisation of Tissue Graft" conducted from 1985 to 2004, many scientists and surgeons were involved in various regional research and development (R&D) projects mainly in dealing with radiation dose selection, radiation effects on human tissues and quality system in radiation sterilisation. New findings on radiation effects, tissue processing and preservation were shared during the regional and interregional meetings and workshops. Many tissue banks started to use radiation (25 kGy) to sterilize tissue grafts for tissue safety and efficacy and still continue to use it. The IAEA Code of Practice for Radiation Sterilization of Tissues Allografts developed in 2007 offered simpler methods to conduct radiation dose setting and dose validation experiments for tissue grafts. Advances in dose selection and dose mapping are continued under the quality management system when banks need to be certified to continue their operation. The combination of good tissue processing and preservation as well as good radiation practice will ensure the tissue products are properly sterilised thus safe and of high quality. Experience in meeting challenges in using radiation sterilisation and achievements reported by the tissue bankers are shared here.

The emergence and pitfalls of international tissue banking.

The rapid growth of tissue banking and associated international organisations following the fall of the Berlin wall in 1991 is described. This surge in collaboration led to a world-wide constructive movement to use and to produce human tissues. As the years progressed industrialisation, led by the USA, improved the quality of tissue allografts but led higher costs and consolidation within the developing industry. The growth of litigation more than kept pace with the industrial progress. One landmark case is described, the outcome of which could revolutionise the current practices now applied to eliminate possible viral contamination of implanted tissue grafts.

Use of a fibrinogen-thrombin sponge in rhinoplasty.

BACKGROUND: Although several methods have been described to address nasal dorsum augmentation and smoothing of irregularities in rhinoplasty, establishing the ideal method has proven controversial. OBJECTIVE: Here, we introduce a novel technique of cartilage grafting for nasal dorsum augmentation by wrapping cartilage in a fibrinogen- and thrombin-coated collagen patch called TachoSil®. MATERIAL AND METHODS: In a pilot study comprising ten cases, the use of the collagen patch was examined in various indications in rhinoplasty. Patients were clinically monitored for up to 8 months and photometric and sonographic documentation was performed pre- and postoperatively. RESULTS: In nine patients, the collagen patch was used for fixation of cartilage grafts in different indications: saddle nose deformities (n = 5), open roof (n = 1), nasal dorsum irregularities (n = 3). A diced cartilage graft enclosed by a bilayer of TachoSil® was applied in seven patients. Solid pieces of cartilage were either embedded in a bilayer of the collagen patch (n = 1) or covered by a monolayer (n = 1). Moreover, the collagen patch alone served as a soft tissue support in one patient with thin skin. Six patients were revision cases. All patients had uneventful healing without adverse events such as allergic reactions and infections. CONCLUSION: The collagen patch TachoSil® is eligible for various indications in rhinoplasty. It is a useful material predominantly for nasal dorsum augmentation by sandwiching diced or solid cartilage in the collagen patch, leading to better graft fixation and precise profile shaping. At the same time, TachoSil® helps with blood control. Follow-up studies will be performed to assess the material's long-term behavior.