Добірка наукової літератури з теми "Keratinized tissues"

An antibody directed against the DNA-binding region of c-fos was used to localize the distribution of cells positive for Fos protein in epithelial tissues. The antibody consistently bound to the nuclei of epithelial cells in the late stages of differentiation, just prior to cornification. The epidermis, palate, buccal mucosa, gingiva, tongue, forestomach and vagina in estrus all produced this type of labelling, suggesting a burst of expression immediately before cell death and cornification. The differentiating cells of the hair follicle, including the hair and inner root sheath, were also labelled. Non-keratinized tissues including junctional epithelium, embryonic epidermis and diestrus vaginal epithelium showed little or no Fos labelling. With the onset of keratinization at 18 days gestation or with induction of estrus in ovariectomized mice with estradiol benzoate, the epidermis and vagina expressed Fos protein in the manner typical for keratinized tissues. The Er/Er mutant epidermis, a tissue that is blocked in its ability to keratinize, overexpresses Fos with Fos-positive cells appearing in virtually every cell layer. Gel shift analysis demonstrates the presence of a functional AP-1 complex in epidermal extracts that is recognized by our antibody. Our data suggest that the expression of Fos is intricately related to epithelial cell differentiation, specifically in relation to the process of cornification and cell death.

The concept of gingival phenotype and width of keratinized gingiva influencing the diagnosis and treatment in the periodontal scenario is relatively new. Soft and hard tissue dimensions of oral tissues are considered essential parameters in daily clinical practice. Factors such as the biotype category and the width of the keratinized gingiva help dentists seek the perfect therapy plan for each patient to achieve long-term stability of periodontal health. Several methods have been proposed to categorize phenotypes and each phenotype is characterized by various clinical characteristics. This review aims to discuss the possible association between the gingival phenotype and the width of keratinized gingiva along with the results appeared. After a rigorous search in major electronic databases, the results of the included studies indicated that the width of keratinized gingiva seems to be associated with the periodontal phenotype, with thick biotypes being characterized by a more pronounced keratinized gingival width. However, the heterogeneity of the included studies did not allow to make a conclusion about a direct relationship.

Insufficiently keratinized tissue can be increased surgically by free gingival grafting. The presence or reconstruction of keratinized mucosa around the implant can facilitate restorative procedure and allow the maintenance of an oral hygiene routine without irritation or discomfort to the patient. The aim of this clinical case report is to describe an oral rehabilitation procedure of an edentulous patient with absence of keratinized mucosa in the interforaminal area, using a free gingival graft associated with a mandibular fixed implant-supported prosthesis. The treatment included the manufacturing of a maxillary complete denture and a mandibular fixed implant-supported prosthesis followed by a free gingival graft to increase the width of the mandibular keratinized mucosa. Free gingival graft was obtained from the palate and grafted on the buccal side of interforaminal area. The follow-up of 02 and 12 months after mucogingival surgery showed that the free gingival graft promoted peri-implant health, hygiene, and patient comfort.Clinical Significance. The free gingival graft is an effective treatment in increasing the width of mandibular keratinized mucosa on the buccal side of the interforaminal area and provided an improvement in maintaining the health of peri-implant tissues which allows for better oral hygiene.

Objective To evaluate the role of keratinized mucosa around dental implants, correlating with other clinical parameters related to the success of dental implants. Design Cross-section. Setting Institutional tertiary referral hospital. Patients A total of 202 dental implants fixed in the cleft area of 109 patients with cleft lip and/or palate were evaluated. Interventions The evaluated clinical parameters were probing depth and gingival and plaque indexes on the buccal surface (three sites). Main Outcome Measures All clinical parameters were correlated with the width of keratinized mucosa around the implants. Results The largest probing depths were detected when the width of keratinized mucosa was 2 mm or more, with a statistically significant difference between the means of the probing depth and keratinized mucosa width. Conclusion Even though the present results suggest that peri-implant health can be observed in areas with keratinized mucosa width under 2 mm provided an adequate oral hygiene control is performed, longitudinal randomized studies are necessary to analyze the relationship between the width of keratinized mucosa and the health of peri-implant tissues.

Objective: Gingival recession is one of the most common esthetic and functional concerns associated with periodontal tissues. Several techniques have been described to cover the exposed root surface. The aim of the present study was to evaluate the efficacy of recession coverage using a coronally repositioned flap in conjunction with a bioresorbable collagen membrane. Methods: Eight non-smoking healthy subjects with Miller’s Class I and II recession defects in the maxillary anterior region were selected. Recession was treated by a coronally repositioned flap along with a bioresorbable type I collagen guided tissue regeneration membrane (Periocol®). Clinical parameters recorded were recession depth, recession width, width of keratinized tissue, and width of the attached gingiva at baseline and 3 months postoperatively. Results: Three-month postoperative measurements demonstrated significant root coverage and a reduction in the recession depth and width. In addition, there was a significant increase in the width of keratinized tissue and of the attached gingiva. Conclusion: Recession coverage with a coronally repositioned and bioresorbable collagen membrane demonstrated good results in terms of root coverage as well as increase in the width of keratinized tissue.

Abstract Alveolar defects are characterized by missing soft and hard tissues. It is often necessary to combine secondary procedures to address the soft-tissue component. The authors describe a technique that uses a split-thickness flap design that is placed over the crest of the remaining ridge and extends in a palatal direction. This allows advancement of the flap with its exposed connective tissue over the bone graft and provides restoration of both bone and keratinized tissue. Seventeen patients with defects involving the anterior maxilla who required grafting procedures were including in this study. All patients had an autogenous bone graft (n = 17) combined with osseointegrated implants (n = 41). A split-thickness flap design was used at the time of bone graft placement (primary) in 9 patients and at the time of implant uncovering (secondary) in 8 patients. There were no cases of flap necrosis or dehiscence with exposure of the bone graft. All patients demonstrated an increase in keratinized tissue involving the peri-implant area. An apical repositioned split-thickness flap provides an increased zone of keratinized tissue with improved esthetics and implant maintenance. This technique can be performed simultaneously with the grafting procedure, thus avoiding extensive undermining of the adjacent soft tissue.

Relevance. It is currently relevant to study and compare the effectiveness of the autologous connective tissue grafts and the combination of collagen-based and autologous platelet-rich plasma in the surgical treatment of Miller Class I gingival recessions.Materials and methods. We examined and treated 48 (20 male (41.67%) and 28 female (58.33%)) patients aged from 25 to 40 years with Miller Class I gingival recessions. All gingival recessions were treated surgically using a modified twolayer tunnel technique. The patients were divided into two groups according to the graft type. Group I (24 patients (50%) had a connective tissue graft from the hard palate. Group II (24 patients (50%) used the combination of the autologous platelet-rich plasma and 3D collagen matrix Fibromatrix for the regeneration of oral soft tissues. We removed the sutures on the 14th day. The patients were followed up on the 7th and 14th days and in 1.3 months.Results. 48 Miller Class I gingival recessions were treated between 2018 and 2020. The depth of gingival recessions averaged 3.5 ± 1.13 mm before treatment. The level of the attached keratinized gingiva regarding the cementoenamel junction significantly (p < 0.001) improved in both groups after the surgery. The width and thickness of the keratinized gingiva best increased in group II. The mean effectiveness of gingival recession treatment was 84% in study group I and 96% – in study group II. Pain syndrome, fibrinous plaque and soft tissue edema were insignificant in group II.Conclusion. The combination of the autologous platelet-rich plasma and Fibromatrix, collagen 3D matrix, for the regeneration of the oral soft tissues is a more effective technique for the treatment of Miller Class I gingival recessions. This technique has several advantages. It is minimally invasive, less painful, soft tissue postoperative swelling is less and the received volume of the attached keratinized gums is larger than with a connective tissue graft.

Germfree transgenic epsilon 26 mice (Tgϵ26), deficient in natural killer cells and T cells, were colonized (alimentary tract) with Candida albicans wild-type or each of two hyphal transcription factor signalling mutant strains (efg1/efg1, efg1/efg1 cph1/cph1). Each Candida strain colonized the alimentary tract, infected keratinized gastric tissues to a similar extent, and induced a granulocyte-dominated inflammatory response in infected tissues. Both wild-type and mutant strains formed hyphae in vivo and were able to elicit an increase in cytokine [tumour necrosis factor alpha, interleukin (IL)-10 and IL-12] and chemokine (KC and macrophage inflammatory protein-2] mRNAs in infected tissues; however, administration of the wild-type strain was lethal for the Tgϵ26 mice, whereas the mice colonized with the mutant strains survived. Death of the Tgϵ26-colonized mice appeared to be due to occlusive oesophageal candidiasis, and not to disseminated candidiasis of endogenous origin. In contrast, the mutant strains exhibited a significantly reduced capacity to infect (frequency and severity) oro-oesophageal (tongue and oesophagus) tissues. Therefore, the two hyphal signalling-defective mutants were less able to infect oro-oesophageal tissues and were non-lethal, but retained their ability to colonize the alimentary tract with yeast and hyphae, infect keratinized gastric tissues, and evoke an inflammatory response in orogastric tissues.

Le mercure (Hg) est un contaminant environnemental qui affecte tous les écosystèmes. Il a la particularité de se biomagnifier le long de la chaîne trophique et de se bioaccumuler dans les tissus des prédateurs. Le Hg est connu pour avoir des effets néfastes chez les humains et la faune sauvage. Les prédateurs des écosystèmes tropicaux sont particulièrement affectés par la contamination en Hg du fait de l’exploitation aurifère artisanale qui utilise d’importantes quantités de Hg pour extraire l’or. Les crocodiliens sont des super-prédateurs des écosystèmes tropicaux et ils accumulent de fortes concentrations de Hg dans leurs tissus. Ils sont potentiellement de bons candidats pour suivre la contamination en Hg, ce sont des animaux vivant plusieurs décennies, ils ont un métabolisme lent et un taux de conversion de l’énergie important, ce qui favorise la bioaccumulation. De plus, ils ont une répartition importante dans les écosystèmes tropicaux et subtropicaux, ce qui rend la surveillance du Hg possible à large échelle. Mes travaux de doctorat s’intéressent aux quatre espèces de caïmans présents en Guyane (le caïman noir Melanosuchus niger, le caïman nain de Cuvier Paleosuchus palpebrosus, le caïman de Schneider Paleosuchus trigonatus et le caïman à lunettes Caiman crocodilus). J’ai travaillé sur les variations de Hg entre différents tissus obtenus par méthode de prélèvement peu invasif et, j’ai étudié l’influence de la morphologie et de l’écologie trophique (via les isotopes stables) des individus sur les concentrations en Hg. Ensuite, j’ai étudié l’impact d’une contamination en Hg sur les mécanismes physiologiques, le transfert maternel et ses effets sur les nouveau-nés
Mercury (Hg) is a global environmental contaminant that affects ecosystems. It has the particularity to biomagnify through the food web, and to bioaccumulate especially in tissues of top predators. Mercury has been identified to have detrimental effects on human and wildlife. Top predators from tropical ecosystems are particularly affected by Hg contamination due to artisanal small scale gold mining, which uses massive amounts of Hg in the gold extraction process. Crocodilians are top predators of tropical ecosystems and have been identified to accumulate high concentrations of Hg in their tissues. They are potentially good candidates to monitor Hg contamination, as they are long-living animals with low metabolic, and high tissue conversion rates, which favours the bioaccumulation of Hg. Additionally, they have a large repartition over tropical and sub-tropical ecosystems, which make large-scale Hg evaluation possible. My doctoral work focuses on the four caiman species that are present in French Guiana (the Black caiman Melanosuchus niger, the Dwarf caiman Paleosuchus palpebrosus, the Smooth-fronted caiman Paleosuchus trigonatus and the Spectacled caiman Caiman crocodilus). First, I have worked on Hg variation across different tissues obtained by minimally invasive methods, and investigated the influence of morphology and feeding ecology (by using stable isotope method) on Hg contamination in caimans. Second, I have investigated the impact of Hg contamination on physiological mechanisms, and the maternal transfer and its effects on neonates

Objetivo: Comprovar a importância da Gengiva Queratinizada circundante aos Implantes Dentários, bem como avaliar os parâmetros clínicos e o impacto que a ausência/presença terá no sucesso do tratamento. Métodos: Realizou-se uma pesquisa bibliográfica com recurso à base de dados PubMed e Science Direct. Foram estabelecidos critérios de inclusão:idioma em Inglês, o limite temporal do ano 2010 até 2021 e pelas palavras-chave. Após a obtenção dos artigos, foram lidos os abstracts e excluídos todos os artigos que não estavam na temática abordada ou cujo conteúdo era repetitivo a nível bibliográfico. Resultados: Foram analisados 11 artigos, nos quais foram avaliados todos os parâmetros clínicos de acordo com a presença/ausência de Gengiva Queratinizada. Conclusões: Após análise e comparação dos artigos revistos, apesar de discordância de um número reduzido de autores, podemos concluir que uma quantidade de Gengiva Queratinizada ≥ a 2 mm diminui a recessão gengival, perda de attachment, índice de placa, perda de crista óssea, inflamação gengival e sangramento.
Objective: To demonstrate the importance of Keratinized Gingiva to Dental Implants, as well as to assess the clinical parameters and the impact that its absence/presence will have on the success of the treatment. Methods: A literature search was carried out using the PubMed and Science Direct databases. Inclusion criteria were added: English, the time limit, from the year 2010 to 2021 and the keywords. After obtaining the articles, the abstracts were read and all articles that were not on the topic addressed or whose content was repetitive at the bibliographical level, were excluded. Results: 11 articles were presented, in which all parameters were obtained according to the presence/absence of Keratinized Gingiva. Conclusions: After analyzing and comparing the articles reviewed, despite the disagreement according to a small number of authors, we can conclude that a quantity of Keratinized Gingiva ≥ 2 mm decreases gingival recession, loss of attachment, plaque index, bone crest loss, gingival inflammation and bleeding.

Trabalho de Projeto do Mestrado Integrado em Medicina Dentária apresentado à Faculdade de Medicina
Introdução: A reabilitação com implantes dentários é considerada um procedimento previsível e cada vez mais frequente na prática clínica diária. O papel desempenhado pelo tecido queratinizado na longevidade dos implantes dentários, é suscetível de controvérsia. Uma banda de tecido queratinizado adequada pode ser importante no controlo de placa e na manutenção da saúde dos tecidos moles peri-implantares. Diversas técnicas têm sido descritas, sendo a vestibuloplastia, através de um retalho de posicionamento apical (RPA/V) em combinação com enxertos autógenos gengivais livre (EGL) ou de tecido conjuntivo (ETC), a mais preconizada. Desvantagens inerentes ao processo de colheita destes enxertos incitaram os clínicos a procurar técnicas alternativas, com resultados previsíveis. A técnica de aumento de tecido queratinizado recorrendo a matrizes de colagénio xenógenas (MCX) combinada com uma banda de enxerto gengival livre (B-EGL) revela-se promissora.Objetivos: O propósito deste trabalho foi realizar uma revisão do tipo sistematizada para avaliar a eficácia clínica da técnica de aumento de tecidos moles peri-implantares, que recorre ao uso de matriz de colagénio xenógena combinada com uma banda de enxerto gengival livre comparando-a com as demais técnicas disponíveis. Adicionalmente, pretende-se reportar um caso clínico em que foi utilizada essa mesma técnica, sendo os seus resultados interpretados à luz da evidência científica disponível apresentada nesta revisão sistematizada da literatura.Material e Métodos: Realizou-se pesquisa bibliográfica na Medline (Pubmed) para estudos em humanos, desde 1 de Janeiro de 1966 até 10 de Abril de 2017. Foram incluídos estudos com metodologia tipo "série de casos com 5 ou mais doentes", "estudos caso-controlo", "estudos coorte", "estudos clínicos controlados", "estudos clínicos randomizados", "revisões sistemáticas" e "meta-análises", com um período mínimo de follow-up de 3 meses. Englobaram-se estudos em que foram avaliados alguns dos seguintes parâmetros: inserção clínica, ganho de altura de tecido queratinizado, volume de tecido, variáveis dependentes do doente como satisfação estética e desconforto pós-operatório. A pesquisa foi complementada com uma pesquisa manual recorrendo a revistas consideradas de referência.Resultados: Após o escrutínio inicial dos títulos e resumos, obtivemos 13 artigos para inclusão na revisão sistematizada: 4 série de casos, 4 estudos clínicos randomizados, 5 revisões sistemáticas. A heterogeneidade entre estudos foi associada a risco de viéses. Resultados significativamente superiores foram obtidos com retalho de posicionamento apical/vestibuloplastia e enxerto gengival livre ou enxerto tecido conjuntivo, no ganho de tecido queratinizado e volume de tecidos moles. No que concerne à morbilidade e tempo operatório, foram alcançados resultados mais favoráveis com matrizes de colagénio, apesar de ocorrer menor queratinização e existir maior contração tecidular (>50%). A aplicação de matriz de colagénio está relacionada com grande variabilidade no ganho de largura de tecido queratinizado (entre 1.5 e 10 mm).Conclusões: Todas as técnicas apresentaram níveis de eficácia, contudo a técnica de eleição continua a ser o retalho de posicionamento apical com enxertos gengivais autógenos. A técnica com retalho de posicionamento apical/vestibuloplastia e matriz de colagénio xenógena + combinada com uma banda de enxerto gengival livre, melhora a morbilidade e conforto do doente e apresenta boa eficácia. A combinação da banda de enxerto gengival livre parece minimizar a contração cicatricial da matriz de colagénio xenógena, podendo assumir-se como alternativa viável, na correção de defeitos peri-implantares.Palavras-chave: gengivoplastia/métodos; tecido queratinizado; enxerto gengival livre; matriz colagénio; autoenxerto gengival; gengiva aderente; aumento tecido mole; implante dentário.
Introduction: Rehabilitation with dental implants is considered a predictable and increasingly frequent procedure in daily clinical practice. The role played by keratinized tissue in the longevity of dental implants, is susceptible to controversy. A suitable keratinized tissue band may be important in plaque control and maintenance of peri-implant soft tissue health. Several techniques have been described, and vestibuloplasty, through an apically positioned flap/vestibuloplasty (APF/V) in combination with free gingival autogenous grafts (FGG) or connective tissue grafts (CTG) is the most recommended technique. Disadvantages inherent to the harvesting process of these grafts prompted clinicians to seek alternative techniques with predictable results. The keratinized tissue augmentation technique using xenogeneic collagen matrices (XCM) combined with a strip free gingival graft (B-FGG) is shown to be promising.Objectives: The purpose of this study was to perform a systematized review to evaluate the clinical efficacy of the peri-implant soft tissue augmentation technique, using xenogeneic collagen matrix combined with a strip free gingival graft and comparing it with other available techniques. Additionally, it is intended to report a clinical case in which the same technique was used, and its results were interpreted based on the available scientific evidence presented in this systematized review of the literature.Methods: We conducted a literature search in Medline (Pubmed) for human studies, from January 1, 1966 to April 10, 2017. Different types of methodology were accepted, ranging from “case series with 5 or more patients”, “Case-control studies”, “cohort studies”, “controlled clinical trials”, “randomized clinical trials”, “systematic reviews” and “meta-analyzes” with a minimum 3 months follow-up period. We included studies in which some of the following parameters were evaluated: clinical insertion, keratinized tissue height gain, tissue volume, dependent variables of the patient such as aesthetic satisfaction and postoperative discomfort. The research was complemented with a manual search using journals considered of reference.Results: After initial scrutiny of titles and abstracts, we obtained 13 articles for inclusion in the systematized review: 4 case series, 4 randomized clinical trials, 5 systematic reviews. Heterogeneity between studies was associated with risk of bias. Significantly higher results were obtained with apically positioned flap/vestibuloplasty and free gingival graft or connective tissue graft for keratinized tissue gain and soft tissue volume. Regarding patient morbidity and surgery time, more favorable results were obtained with collagen matrices, although less keratinization occurred and there was greater tissue contraction (> 50%). The application of collagen matrix is related to great variability in the increase of keratinized tissue width (between 1.5 and 10 mm).Conclusions: All techniques presented levels of efficacy, however, the technique of choice remains the apically positioned flap/vestibuloplasty with autogenous gingival grafts. The apically positioned flap/vestibuloplasty and xenogeneic collagen matrix + strip free gingival graft technique improves patient morbidity and comfort and has good efficacy. The combination of a strip free gingival graft seems to minimize xenogeneic collagen matrix scar tissue contraction and may be a viable alternative in the correction of peri-implant defects.Key-words: gingivoplasty/methods; keratinized tissue; free gingival graft; collagen matrix; gingival autograft; attached gingiva; soft tissue augmentation; dental implant
Universidade de Coimbra - 500 euros

Objetivo: Revisão da literatura científica referente aos resultados clínicos de procedimentos cirúrgicos para aumento da largura de tecido queratinizado peri-implantar. Métodos: Realizada uma pesquisa com recurso à base de dados PubMed para execução desta revisão literatura. Foram aplicados critérios de inclusão, tais como estudos clínicos controlados aleatorizados, tempo de seguimento mínimo de 3 meses, procedimentos mucogengivais em implantes para aumento de tecido queratinizado e estudos em humanos. Resultados: Analisados 5 artigos que comparavam diferentes materiais para o aumento de tecido queratinizado peri-implantar, tais como o enxerto de tecido conjuntivo, matriz de colagénio xenogénica, matriz dérmica acelular, matriz colagénio, enxerto de tecido conjuntivo subepitelial e fibrina rica em plaquetas preparada com titânio. Conclusões: Nos estudos analisados conseguimos evidenciar uma tendência de superioridade do enxerto de tecido conjuntivo (ETC) para o aumento de tecido queratinizado peri-implantar, no entanto, alguns estudos não comprovaram diferenças estatisticamente significativas.
Objectives: Review of the scientific literature regarding the clinical results of surgical procedures to increase the width of peri-implant keratinized tissue. Methods: A search was carried out using the PubMed database to carry out the literature revision. Inclusion and exclusion criteria were applied, such as randomized controlled clinical studies, minimum follow-up time of 3 months, mucogingival procedures in implants for keratinized tissue augmentation and studies in humans. Results: Five articles were analyzed comparing different materials for peri-implant keratinized tissue augmentation, such as connective tissue graft, xenogeneic collagen matrix, acellular dermal matrix, collagen matrix, subepithelial connective tissue graft and platelet-rich fibrin prepared with titanium. Conclusions: In the analyzed studies, we were able to show a trend towards superiority of the connective tissue graft (ETC) for the increase of peri-implant keratinized tissue, however, some studies did not prove statistically significant differences.

Objetivo: Revisão da literatura focada na comparação entre duas matrizes de colagénio de referência na Europa, Mucograft® e Mucoderm®. Análise dos resultados clínicos, com ênfase na percentagem de recobrimento radicular e no aumento de tecido queratinizado. Métodos: Realizou-se uma pesquisa bibliográfica com recurso à base de dados PubMed. Foram estabelecidos critérios de inclusão e exclusão, tendo sido incluídos apenas estudos clínicos randomizados. Resultados: Foram analisados dezoito estudos, nos quais foi descrito o aumento de tecido queratinizado e a redução de recessão gengival. Conclusões: Face à ausência de estudos comparativos entre as duas matrizes, a literatura disponível relativa à matriz Mucoderm® não permite estabelecer conclusões face à matriz Mucograft®.
Objectives: Literature review focused on the comparison between two well-known collagen matrices in Europe, Mucograft® and Mucoderm®. Anaysis of clinical outcomes, focusing on root coverage percentage and augmentation of keratinized tissue. Methods: A bibliographical research in the PubMed database was performed. Inclusion and exclusion criteria were established, being only included randomised clinical trials. Results: Eighteen studies were analysed, in which keratinized tissue augmentation and gingival recession reduction were presented. Conclusions: In the absence of studies comparing these two matrices, the remaining literature concerning the Mucoderm® matrix does not allow drawing any conclusions when comparing it with the Mucograft® matrix.

A presença de uma gengiva queratinizada ao redor de implantes parece ter um papel biológico protetor que torna o tecido peri-implantar mais resistente a traumas mecânicos e biológicos. A estabilidade dos tecidos peri-implantares depende de inúmeros fatores como, posição tridimensional dos implantes, fenótipo gengival, tipo de implante, componente protético entre outros, mas a presença de gengiva queratinizada tem mostrado ser um fator importante para a estabilidade do tecido peri-implantar a longo prazo. Estudos recentes mostram que a falta de gengiva queratinizada ao redor de implantes ocasiona um controle do biofilme menos eficiente, podendo originar consequência(s) como, inflamação e recessão tecidual. Os produtos bacterianos vindos do biofilme dental induzem a ativação de citoquinas pró-inflamatórias (TNF-α) que agravam a resposta inflamatória ao redor de implantes. Um dos principais motivos que dificultam o controle do biofilme em implantes com pouca gengiva queratinizada é o desconforto ou sensação dolorosa relatada pelo paciente durante os procedimentos de higiene oral e a dificuldade de se higienizar o local. Portanto a presença de gengiva queratinizada ao redor de implantes contribui para o conforto do paciente e, consequentemente promove saúde e estabilidade periimplantar.
The presence of a keratinized gingiva around implants appears to have a protective biological role that makes the peri-implant tissue more resistant to mechanical and biological trauma. The stability of peri-implant tissues depends on innumerable factors such as three-dimensional position of the implants, gingival phenotype, type of implant, prosthetic component among others, but the presence of keratinized gingiva has been shown to be an important factor for the stability of periimplant tissue long-term. Recent studies show that the lack of keratinized gingiva around implants causes less efficient biofilm control, which may result in inflammation and tissue recession. Bacterial products from the dental biofilm induce the activation of proinflammatory cytokines (TNF-α) that aggravate the inflammatory response around implants. One of the main reasons that hinder biofilm control in implants with little keratinized gingiva is the discomfort or painful sensation reported by the patient during oral hygiene procedures and the difficulty of hygienizing the site. Therefore, the presence of keratinized gingiva around implants contributes to patient comfort and, consequently, promotes peri-implant health and stability.

Entropion is a posterior rotation of the upper or lower lid margin against the globe; the causes include involutional changes within the eyelid tissues or cicatricial shortening of the posterior lamella of the eyelid. Congenital lower lid entropion is rare and results from an excess of skin and orbicularis oculi muscle being only loosely attached to the eyelid retractors. The symptoms of entropion—which include ocular irritation, lid spasm, pain, redness, and watering—are worse in the presence of a keratinized lid margin (occurring in cicatricial disease) and where the ocular surface is compromised. Discomfort may lead to secondary blepharospasm, which exacerbates the entropion by causing the preseptal part of the orbicularis muscle to override the pretarsal component. The eyelids and globe should be examined to identify underlying causative factors—in particular the degree and position of tissue laxity, the position of the eyelid margin and lashes, and the thickness of the tarsus. Any secondary effects of entropion, both within the lid and on the ocular surface, should also be noted. 7-1-1 Tissue Laxity. Aging of collagen and the force of gravity leads to eyelid laxity and an excess of tissues, particularly the anterior lamella of the lid. Stretching of the orbicularis muscle and canthal tendons results in horizontal laxity, and eyelid stability is further compromised by enophthalmos due to age-related fat atrophy. Where there is a relative dissociation between the anterior and posterior lamellae, the preseptal orbicularis muscle overrides the pretarsal muscle, leading to eyelid inversion, and this effect is exacerbated both by laxity of the lower lid retractors and age-related tarsal atrophy. Tissue laxity in the absence of orbicularis overriding tends to cause ectropion; with complete loss of retractor action, this can result in complete eversion of the tarsus (“shelf ectropion”). Horizontal laxity of the eyelid tissues is assessed by grasping the lid skin and applying gentle traction in the appropriate direction. The overall horizontal laxity is judged by the extent to which the eyelid can be parted from the globe—greater than about 6 mm is abnormal for a lower eyelid—and by the speed with which the retracted lid returns to the surface of the globe (the “spring-back” test).

Dental implants have become a well-accepted treatment option for patients with partial or complete edentulism. The long-term success of the endosseous dental implant depends not only on osseointegration, but on the healthy soft tissue interface that surrounds the implant. Peri-implantitis is defined as an inflammatory process affecting the supporting hard and soft tissue around an implant in function, leading to loss of supporting bone. Peri-implant mucositis has been defined as a reversible inflammatory reaction in the peri-implant mucosa surrounding an osseointegrated dental implant. Peri-implant mucositis is assumed to precede peri-implantitis. Data indicate that patients diagnosed with peri-implant mucositis may develop peri-implantitis, especially in the absence of regular maintenance care. However, the features or conditions characterizing the progression from peri-implant mucositis to peri-implantitis in susceptible patients have not been identified. The most common etiological factors associated with the development of peri-implantitis are the presence of bacterial plaque and host response. The risk factors associated with peri-implant bone loss include smoking combined with IL-1 genotype polymorphism, a history of periodontitis, poor compliance with treatment and oral hygiene practices, the presence of systemic diseases affecting healing, cement left behind following cementation of the crowns, lack of keratinized gingiva, and previous history of implant failure There is strong evidence that there is an increased risk of developing peri-implantitis in patients who have a history of severe periodontitis, poor plaque control, and no regular maintenance care after implant therapy. Management of peri-implantitis generally works on the assumption that there is a primary microbial etiology. Furthermore, it is assumed that micro-organisms and/or their by-products lead to infection of the surrounding tissues and subsequent destruction of the alveolar bone surrounding an implant. A combination of surgical, open debridement, and antimicrobial treatment has been advocated for the treatment of peri-implantitis. Surgical intervention is required once a patient has bleeding on probing, greater than 5 mm of probing depth, and severe bone loss beyond that expected with remodeling. Access flaps require full-thickness elevation of the mucoperiosteum, facilitating debridement and decontamination of the implant surface via hand instruments, ultrasonic tips, or lasers. When necessary, surgical procedures may be used in conjunction with detoxification of the implant surface by mechanical devices, such as high-pressure air powder abrasion or laser.

The peri-implant soft tissue (PIS) augmentation procedure has become an integral part of implant-prosthetic rehabilitation. Minimal width of keratinized mucosa (KM) of 2 mm is deemed necessary to facilitate oral hygiene maintenance around the implant and provide hard and soft peri-implant tissue stability. PIS thickness of at least 2 mm is recommended to achieve the esthetic appearance and prevent recessions around implant prosthetic rehabilitation. The autogenous soft tissue grafts can be divided into two groups based on their histological composition—free gingival graft (FGG) and connective tissue graft (CTG). FGG graft is used mainly to increase the width of keratinized mucosa while CTG augment the thickness of PIS. Both grafts are harvested from the same anatomical region—the palate. Alternatively, they can be harvested from the maxillary tuberosity. Soft tissue grafts can be also harvested as pedicle grafts, in case when the soft tissue graft remains attached to the donor site by one side preserving the blood supply from the donor region. Clinically this will result in less shrinkage of the graft postoperatively, improving the outcome of the augmentation procedure. To bypass the drawback connected with FGG or CTG harvesting, substitutional soft tissue grafts have been developed.

The oral mucosa lines the oral cavity and comprises a surface squamous epithelium with underlying lamina propria. Below the mucosa is the submucosa, which is composed of fibrous tissue and adipose tissue, and contains lobules of minor salivary glands and neurovascular bundles. In places, there is no submucosa and the lamina propria is continuous with periosteum, forming the resilient mucoperiosteum that covers the maxilla and mandible. The squamous epithelium is composed of keratinocytes arranged in lay­ers: there is a basal cell layer that rests on the basement membrane, a prickle cell layer, and usually a keratinized layer. The keratino­cytes are attached to each other by desmosomes and the basal keratino­cytes are attached to the basement membrane by hemi- desmosomes. The basement membrane is important in maintaining the integrity of the mucosa by sticking the squamous epithelium to the underlying lamina propria. There are two patterns of keratinization: par­akeratosis and orthokeratosis. In parakeratinized epithelium the surface keratinocytes become flattened and the nucleus becomes dark and shrunken (pyknotic). These terminally differentiated squamous cells are eventually lost at the surface by desquamation. In orthokeratiniza­tion, there is a granular cell layer (containing numerous keratohyaline granules) between the prickle cell layer and the keratinized layer. The surface squames become flattened and do not contain any discernible nuclear material. Whilst the majority of cells in squamous epithelium are keratinocytes, there are also accessory cells such as melanocytes, Langerhans cells, and neurosensory cells (Merkel cells and taste buds). The lamina propria is the connective tissue that lies immediately below the epithelium. It is divided into the superficial papil­lary layer (sometimes referred to as the corium) and the deeper reticu­lar layer. The lamina propria is composed of fibrous tissue with a rich neurovascular supply and contains fibroblasts that elaborate collagen and elastin fibres along with other extracellular matrix proteins. The lamina propria also contains components of the mucosal immune defence system such as Langerhans cells, macrophages, mast cells, and lymphocytes. The clinical appearance of the oral mucosa is dependent on the thick­ness of the epithelium, the amount of surface keratinization, melanin (and other) pigmentation, and the vascularity of the lamina propria.

Skin is a specialized boundary tissue which forms the entire external surface of the body and is continuous with mucosa lining the respiratory, gastrointestinal, and urinogenital tracts at their respective openings. Skin is the largest organ in the body but is often overlooked in this respect. Skin has many functions, some of which are not immediately obvious. • It minimizes damage from mechanical, thermal, osmotic, chemical, and sunlight insults. • It forms a barrier against microorganisms. • It has a major function in thermoregulation. • It is a sensory surface equipped with touch, pressure, temperature, and pain receptors. • It has good frictional properties useful in locomotion and handling objects. • It is waterproof. • It is the site of vitamin D synthesis. • It also plays a role in non-verbal communication when we blush, alter our facial expression, or use tactile communication such as touching or kissing. Skin has two distinct parts when seen under a microscope, the superficial epidermis and the deeper dermis. The epidermis is a surface epithelium in which the outer cells are keratinized. Keratinization is the deposition of tough mats of keratin which are intracellular fibrous proteins that make the cells tough; keratinization also kills the superficial cells so the outer layers of your skin are dead. The epidermis varies in thickness. The thickest and most heavily keratinized areas are on the soles of the feet and palms of the hands whereas the epidermis on the face and back of the hand is much thinner and less heavily keratinized. Habitual activity, such as holding a pen, digging with a shovel or using scissors, may produce localized thickenings of thick skin by increasing the thickness of keratin to produce calluses. Cells below the keratin layer have a special coating that forms a permeability barrier, preventing water moving between cells, thus preventing water loss from the body and water-logging when exposed to water. Epithelium does not contain blood vessels, which is why you do not bleed when you lightly knock your skin. To bleed, you need to expose the blood vessels that lie in the dermis and supply the overlying epidermis by diffusion of nutrients through fenestrated capillaries.

Appropriate evaluation of an eyelid lesion is necessary before deciding on a course of surgical or nonsurgical treatment. A differential diagnosis is established based on the patient’s history and the physical characteristics of the mass. Many eyelid masses have similar physical and behavioral characteristics. In some cases, radiologic examination can be helpful in determining the extent or even the type of tumor. Certain malignant tumors may look benign or have the appearance of other malignancies. Biopsy is required for the definitive diagnosis. When faced with an eyelid lesion, the physician must first determine whether the lesion is benign or malignant. This determination will then dictate the next direction of diagnostic tests. If a mass has been present for several months to years or if there has been a history of bleeding, malignancy must be considered. Pain is usually not a component of malignancy, but some moderate discomfort may be present. Malignant lesions are usually destructive. The skin may be altered by a mass or ulceration. A malignancy located at the eyelid margin usually results in loss of lashes. Small malignancies may be similar in appearance to early inflammations, but as these malignancies grow, destruction of tissue is usually evident. If malignancy is not suspected, then a decision as to whether the lesion is inflammatory or not should be made. Small inflammatory lesions such as blepharitis may be ulcerative, cause loss of lashes, and simulate eyelid carcinoma. Swelling, redness, and pain are all characteristics of inflammatory masses such as styes or chalazia. Infected glands away from the lid margin can also have these signs. Swelling in the area of the medial canthus could be a lacrimal sac mucocele if there is no evidence of redness, or it could be a lacrimal sac tumor. Benign lesions that are not inflammatory may have swelling but usually not pain. They may be translucent, such as hair follicle cysts. These tumors often transilluminate. They may have a clear fluid that can be easily identified through thin skin, or there may be a yellowish content such as sebaceous material within the cyst. Some benign lesions may be papillomatous or have keratinized ends, such as cutaneous horns.