Effects of platelet-rich fibrin produced by three centrifugation protocols on bone neoformation in defects created in rat calvaria.

This study evaluated the potential of Leukocyte-platelet-rich fibrin (L-PRF; fixed angle centrifugation protocol), Advanced-platelet-rich fibrin (A-PRF; low-speed fixed angle centrifugation protocol), and Horizontal-platelet-rich fibrin (H-PRF; horizontal centrifugation protocol) in bone neoformation in critical size defects (CSDs) in rat calvaria. Thirty-two rats were divided into groups: Control (C), L-PRF, A-PRF, and H-PRF. 5 mm diameter CSDs were created in the animals' calvaria. Defects from group Control (C) were filled with blood clots, while defects from groups L-PRF, A-PRF, and H-PRF were filled with respective platelet-rich fibrin (PRF) membranes. L-PRF, A-PRF, and H-PRF were prepared from animal blood collection and specific centrifugation protocols. At 14 and 30 days, calcein (CA) and alizarin (AL) injections were performed, respectively. Animals were euthanized at 35 days. Microtomographic, laser confocal microscopy, and histomorphometric analyzes were performed. Data were statistically analyzed (ANOVA, Tukey, p < .05). L-PRF, A-PRF, and H-PRF groups showed higher values of bone volume (BV), newly formed bone area (NFBA), and precipitation of CA and AL than the C group (p < .05). The H-PRF group showed higher values of BV, number of trabeculae (Tb. N), NFBA, and higher precipitation of AL than the A-PRF and L-PRF groups (p < .05). Therefore, it can be concluded that: i) L-PRF, A-PRF, and H-PRF potentiate bone neoformation in CSDs in rat calvaria; ii) H-PRF demonstrated more biological potential for bone healing.

After tooth loss, the alveolar bone (which supports the teeth) undergoes a natural process called bone remodeling, which can lead to significant decreases in bone height and thickness over time. Faced with the need to replace missing teeth, especially when it comes to dental implants, the lack of supporting tissues can compromise their correct positioning, leading to negative impacts on the success and longevity of the treatment. Therefore, over the years, several materials and procedures have been proposed to preserve and regenerate oral tissues. Leukocyte-platelet-rich fibrin (L-PRF) consists of a membrane obtained by centrifuging the patient's blood in a fixed-angle centrifuge, allowing cells to be available to stimulate tissue regeneration directly at the place of action. Several reports demonstrate high potential in stimulating the formation of new tissues using L-PRF. In recent years, new protocols have been proposed to increase cell concentration and improve the regenerative potential of these membranes, changing the speed and time of centrifugation and introducing horizontal centrifugation. However, there still needs to be concrete evidence of the superiority of the new protocols in relation to the original protocol. In this study, we evaluated the healing of defects created in rat calvaria using platelet aggregates obtained through different centrifugation protocols. Within the limits of this study, it can be concluded that platelet aggregates improve bone healing, and horizontal centrifugation promotes more satisfactory results compared to fixed-angle protocols.

Mesenchymal stem cells surpass the capacity of bone marrow aspirate concentrate for periodontal regeneration.

Regenerative approaches using mesenchymal stem cells (MSCs) have been evaluated to promote the complete formation of all missing periodontal tissues, e.g., new cementum, bone, and functional periodontal ligaments. MSCs derived from bone marrow have been applied to bone and periodontal defects in several forms, including bone marrow aspirate concentrate (BMAC) and cultured and isolated bone marrow mesenchymal stem cells (BM-MSCs). This study aimed to evaluate the periodontal regeneration capacity of BMAC and cultured BM-MSCs in the wound healing of fenestration defects in rats. METHODOLOGY: BM-MSCs were obtained after bone marrow aspiration of the isogenic iliac crests of rats, followed by cultivation and isolation. Autogenous BMAC was collected and centrifuged immediately before surgery. In 36 rats, fenestration defects were created and treated with suspended BM-MSCs, BMAC or left to spontaneously heal (control) (N=6). Their regenerative potential was assessed by microcomputed tomography (µCT) and histomorphometry, as well as their cell phenotype and functionality by the Luminex assay at 15 and 30 postoperative days. RESULTS: BMAC achieved higher bone volume in 30 days than spontaneous healing (p<0.0001) by enhancing osteoblastic lineage commitment maturation, with higher levels of osteopontin (p=0.0013). Defects filled with cultured BM-MSCs achieved higher mature bone formation in early stages than spontaneous healing and BMAC (p=0.0241 and p=0.0143, respectively). Moreover, significantly more cementum-like tissue formation (p<0.0001) was observed with new insertion of fibers in specimens treated with BM-MSCs within 30 days. CONCLUSION: Both forms of cell transport, BMAC and BM-MSCs, promoted bone formation. However, early bone formation and maturation were achieved when cultured BM-MSCs were used. Likewise, only cultured BM-MSCs were capable of achieving complete periodontal regeneration with inserted fibers in the new cementum-like tissue.

Mesenchymal stem cells surpass the capacity of bone marrow aspirate concentrate for periodontal regeneration

Abstract Regenerative approaches using mesenchymal stem cells (MSCs) have been evaluated to promote the complete formation of all missing periodontal tissues, e.g., new cementum, bone, and functional periodontal ligaments. MSCs derived from bone marrow have been applied to bone and periodontal defects in several forms, including bone marrow aspirate concentrate (BMAC) and cultured and isolated bone marrow mesenchymal stem cells (BM-MSCs). This study aimed to evaluate the periodontal regeneration capacity of BMAC and cultured BM-MSCs in the wound healing of fenestration defects in rats. Methodology: BM-MSCs were obtained after bone marrow aspiration of the isogenic iliac crests of rats, followed by cultivation and isolation. Autogenous BMAC was collected and centrifuged immediately before surgery. In 36 rats, fenestration defects were created and treated with suspended BM-MSCs, BMAC or left to spontaneously heal (control) (N=6). Their regenerative potential was assessed by microcomputed tomography (µCT) and histomorphometry, as well as their cell phenotype and functionality by the Luminex assay at 15 and 30 postoperative days. Results: BMAC achieved higher bone volume in 30 days than spontaneous healing (p<0.0001) by enhancing osteoblastic lineage commitment maturation, with higher levels of osteopontin (p=0.0013). Defects filled with cultured BM-MSCs achieved higher mature bone formation in early stages than spontaneous healing and BMAC (p=0.0241 and p=0.0143, respectively). Moreover, significantly more cementum-like tissue formation (p<0.0001) was observed with new insertion of fibers in specimens treated with BM-MSCs within 30 days. Conclusion: Both forms of cell transport, BMAC and BM-MSCs, promoted bone formation. However, early bone formation and maturation were achieved when cultured BM-MSCs were used. Likewise, only cultured BM-MSCs were capable of achieving complete periodontal regeneration with inserted fibers in the new cementum-like tissue.

Effect of implant crestal position on primary stability before and after loading: an in vitro study / Efeito do posicionamento crestal do implante na estabilidade primária antes e após carga: um estudo in vitro

Introduction: Primary stability is one of the goals of modern implant dentistry and if achieved, reduces treatment time for prosthetic rehabilitation and the number of interventions made in patients mouth. Several companies state as protocol for connical conection implants, a subcrestally positioning. Objective: This in vitro study aimed to evaluate the effect of placing a conical connection implant equicrestally and subcrestally on static and loading condition in two types of bone density. Material and method: A total of 200 bone cylinders were extracted from femur of pigs, standardized by means of x-rays and computerized microtomography scan (microCT) and separated in low and high density specimens. The implants were placed on the center of the bone cylinders and were evaluated before and after loading by means of microCT and histomorphometry. Result: The results showed that placing the evaluated implant subcrestally provided better primary stability and performance on static and loading situations on low and high density bone. Conclusion: Placing implant subcrestally improve primary stability outcomes under loading and static situations.

Introdução: A estabilidade primária é um dos objetivos da implantodontia moderna e, caso atingida, reduz o tempo de tratamento para a reabilitação protéticas e o número de intervenções realizadas. Diversas empresas preconizam a posição subcrestal no uso de implantes com conexão cônica interna. Objetivo: Este estudo in vitro avaliou o efeito do posicionamento de implantes de conexão conica interna sub e equicrestal sob condições estáticas e em função, considerando dois tipos de densidades ósseas. Material e método: um total de 200 espécimes de osso extraído do femur de suínos e padronizados por meio de radiografias e microtomografias computadorizadas foram separados em densidade alta e baixa. Implantes foram instalados no centro dos especimes e for a avaliados por meio de microCT e histomorfometria. Resultado: Os resultados demonstraram que a colocação de implante subcrestalmente promoveu melhor estabilidade primária e performance em todas as situações, irrespectivamente à densidade óssea. Conclusão: A colocação de implantes subcrestalmente melhora a estabilidade primária em todas as situações, sendo indicada quando da utilização de conexões cônicas internas.

Clinical attachment loss and molecular profile of inflamed sites before treatment.

OBJECTIVE: To monitor early periodontal disease progression and to investigate clinical and molecular profile of inflamed sites by means of crevicular fluid and gingival biopsy analysis. METHODOLOGY: Eighty-one samples of twenty-seven periodontitis subjects and periodontally healthy individuals were collected for the study. Measurements of clinical parameters were recorded at day -15, baseline and 2 months after basic periodontal treatment aiming at monitoring early variations ofthe clinical attachment level. Saliva, crevicular fluid and gingival biopsies were harvested from clinically inflamed and non-inflamed sites from periodontal patients and from control sites of healthy patients for the assessment of IL-10, MMP-8, VEGF, RANKL, OPG and TGF-ß1 protein and gene expression levels. RESULTS: Baseline IL-10 protein levels from inflamed sites were higher in comparison to both non-inflamed and control sites (p<0.05). Higher expression of mRNA for IL-10, RANK-L, OPG, e TGF-ß1 were also observed in inflamed sites at day -15 prior treatment (p<0.05). After the periodontal treatment and the resolution of inflammation, seventeen percent of evaluated sites still showed clinically detectable attachment loss without significant differences in the molecular profile. CONCLUSIONS: Clinical attachment loss is a negative event that may occur even after successful basic periodontal therapy, but it is small and limited to a small percentage of sites. Elevated inflammation markers of inflamed sites from disease patients reduced to the mean levels of those observed in healthy subjects after successful basic periodontal therapy. Significantly elevated both gene and protein levels of IL-10 in inflamed sites prior treatment confirms its modulatory role in the disease status.

Clinical attachment loss and molecular profile of inflamed sites before treatment

Abstract Objective: To monitor early periodontal disease progression and to investigate clinical and molecular profile of inflamed sites by means of crevicular fluid and gingival biopsy analysis. Methodology: Eighty-one samples of twenty-seven periodontitis subjects and periodontally healthy individuals were collected for the study. Measurements of clinical parameters were recorded at day −15, baseline and 2 months after basic periodontal treatment aiming at monitoring early variations ofthe clinical attachment level. Saliva, crevicular fluid and gingival biopsies were harvested from clinically inflamed and non-inflamed sites from periodontal patients and from control sites of healthy patients for the assessment of IL-10, MMP-8, VEGF, RANKL, OPG and TGF-β1 protein and gene expression levels. Results: Baseline IL-10 protein levels from inflamed sites were higher in comparison to both non-inflamed and control sites (p<0.05). Higher expression of mRNA for IL-10, RANK-L, OPG, e TGF-β1 were also observed in inflamed sites at day −15 prior treatment (p<0.05). After the periodontal treatment and the resolution of inflammation, seventeen percent of evaluated sites still showed clinically detectable attachment loss without significant differences in the molecular profile. Conclusions: Clinical attachment loss is a negative event that may occur even after successful basic periodontal therapy, but it is small and limited to a small percentage of sites. Elevated inflammation markers of inflamed sites from disease patients reduced to the mean levels of those observed in healthy subjects after successful basic periodontal therapy. Significantly elevated both gene and protein levels of IL-10 in inflamed sites prior treatment confirms its modulatory role in the disease status.

Substitutos ósseos sintéticos na Implantodontia / Synthetic bone substitutes for Implant Dentistry ­ a literature review

Objetivo: analisar sistematicamente, na literatura científica, o uso de substitutos ósseos sintéticos na regeneração óssea para Implantodontia. Material e métodos: uma busca foi realizadas nas bases de dados PubMed, Cochrane, LILACS e SciELO, nos últimos quinze anos, combinando as palavras-chave "regeneração óssea", "materiais biocompatíveis", "implantes dentários", e "materiais aloplásticos". Resultados: Dos 199 artigos inicialmente recuperados, apenas 27 foram selecionados, incluindo revisões sistemáticas/ metanálises (n=2), revisões da literatura (n=1), estudos clínicos (n=9) e pré-clínicos (n=12), relato de caso (n=1) e tese (n=1). Nos modelos animais, o vidro bioativo é capaz de provocar formação óssea à distância, inibir a migração apical do epitélio juncional, e gerar maior deposição de cemento na superfície radicular. Partículas esféricas geram melhor dissolução e integração com o novo osso circundante, e bons resultados são vistos nas técnicas de ROG e RTG. Em um estudo clínico randomizado, o vidro bioativo misturado ao osso autógeno para regeneração de defeitos intraósseos reduziu significativamente a profundidade de sondagem, com ganho de nível clínico de inserção, e resolução dos defeitos já aos seis meses. Nos modelos animais, a tríade hidroxiapatita (HA), beta-fosfato tricálcio (ß-TCP), e fosfato de cálcio bifásico (HA+ ß-TCP) tem se mostrado biocompatível, biorreabsorvível e osteocondutora. Um estudo clínico controlado com HA+ ß-TCP/ membrana revelou melhor preservação óssea vertical e horizontal comparado ao coágulo/membrana, nas TCFCs de seis meses. Regenerações ósseas verticais significativas com estes materiais sintéticos são potencializadas pelo uso dos fatores de crescimento. Conclusão: substitutos ósseos sintéticos demonstram uso promissor para regeneração. Entretanto, a evidência clínica deve ser substancialmente aumentada.

Objective: to systematically analyze in the scientifi c literature the use of synthetic bone substitutes for bone regeneration in implant dentistry. Material and methods: a search was conducted at the PubMed, Cochrane, LILACS and SciELO databases considering the last fi fteen years, and combining the keywords "bone regeneration", "biocompatible materials", "dental implants", and "alloplastic materials". Results: of the 199 articles initially retrieved, only 27 were selected, including systematic reviews/meta-analysis (n=2), literature reviews (n=1), clinical (n=9) and pre-clinical (n=12) studies, case report (n=1) and thesis (n=1). In animal models, the bioactive glass can cause bone formation at distance, inhibit apical migration of the junctional epithelium, and generate greater deposition of cementum over the root surface. Spherical particles generate better dissolution and integration with the new surrounding bone, and good results are seen in the ROG and RTG techniques. In a randomized study, the bioactive glass mixed with autogenous bone to regenerate intra-osseous defects signifi cantly reduced probing depths, with clinical attachment level gains, and defect resolution as early as 6 months. In animal models, the triad hydroxyapatite (HA), beta-tricalcium phosphate (ß-TCP), and biphasic calcium phosphate (HA + ß-TCP) has been shown to be biocompatible, bioresorbable, and osteoconductive. A controlled clinical study with (HA + ß-TCP/membrane) showed better vertical and horizontal bone preservation compared to clot / membrane at the 6 month CBCT images. Also, signifi cant vertical bone regeneration with these synthetic materials is enhanced by the use of growth factors. Conclusion: the synthetic bone substitutes are good candidates for regeneration. However, the level of clinical evidence must be substantially increased.

A Randomized Comparative Study of Two Techniques to Optimize the Root Coverage Using a Porcine Collagen Matrix.

The aim of this randomized controlled clinical study was to compare the extended flap technique (EFT) with the coronally advanced flap technique (CAF) using a porcine collagen matrix (PCM) for root coverage. Twenty patients with two bilateral gingival recessions, Miller class I or II on non-molar teeth were treated with CAF+PCM (control group) or EFT+PCM (test group). Clinical measurements of probing pocket depth (PPD), clinical attachment level (CAL), recession height (RH), keratinized tissue height (KTH), keratinized mucosa thickness (KMT) were determined at baseline, 3 and 6 months post-surgery. At 6 months, the mean root coverage for test group was 81.89%, and for control group it was 62.80% (p<0.01). The change of recession depth from baseline was statistically significant between test and control groups, with an mean of 2.21 mm gained at the control sites and 2.84 mm gained at the test sites (p=0.02). There were no statistically significant differences for KTH, PPD or CAL comparing the two therapies. The extended flap technique presented better root coverage than the coronally advanced flap technique when PCM was used.

A Randomized Comparative Study of Two Techniques to Optimize the Root Coverage Using a Porcine Collagen Matrix

Abstract: The aim of this randomized controlled clinical study was to compare the extended flap technique (EFT) with the coronally advanced flap technique (CAF) using a porcine collagen matrix (PCM) for root coverage. Twenty patients with two bilateral gingival recessions, Miller class I or II on non-molar teeth were treated with CAF+PCM (control group) or EFT+PCM (test group). Clinical measurements of probing pocket depth (PPD), clinical attachment level (CAL), recession height (RH), keratinized tissue height (KTH), keratinized mucosa thickness (KMT) were determined at baseline, 3 and 6 months post-surgery. At 6 months, the mean root coverage for test group was 81.89%, and for control group it was 62.80% (p<0.01). The change of recession depth from baseline was statistically significant between test and control groups, with an mean of 2.21 mm gained at the control sites and 2.84 mm gained at the test sites (p=0.02). There were no statistically significant differences for KTH, PPD or CAL comparing the two therapies. The extended flap technique presented better root coverage than the coronally advanced flap technique when PCM was used.

Resumo: O objetivo deste estudo randomizado, controlado e clínico foi comparar para recobrimento radicular a técnica de retalho estendido (EFT) com a técnica de retalho avançado coronalmente (CAF) utilizando uma matriz suína colágena (PCM). Vinte pacientes com duas retrações gengivais bilaterais, classe I ou II de Miller em dentes não molares foram tratados com PCM+CAF (grupo controle) ou PCM+EFT (grupo teste). Medidas clínicas de profundidade de sondagem, (PPD), nível clínico de inserção (CAL), altura da retração gengival (RH), altura do tecido queratinizado (KTH), espessura da mucosa queratinizada (KMT) foram determinadas no exame inicial, aos 3 e 6 meses após a realização das cirurgias. Após 6 meses a média de recobrimento radicular para o grupo teste foi de 81,89% e para o grupo controle foi de 62,80% (p<0,01). A mudança na altura das retrações gengivais em relação ao exame inicial foi estatisticamente significante entre os grupos teste e controle, com média de 2,21 mm ganhos nos sítios controle e 2,84 mm ganhos nos sítios teste (p=0,02). Não houve diferenças estatísticas significantes para os parâmetros KTH, PPD ou CAL comparando as duas terapias. A técnica de retalho estendido apresentou melhor recobrimento radicular do que a técnica de retalho avançado coronalmente quando a PCM foi usada.

Auxiliary chemical therapies in the treatment of aggressive periodontitis: current aspects / Terapias químicas auxiliares para o tratamento da periodontite agressiva: aspectos atuais

Aggressive periodontitis, a distinct clinical entity of periodontal disease, is characterized by a pronounced episodic and rapid destruction of periodontal tissues and may result in rapid and early loss of teeth. Some studies have shown that conventional mechanical debridement together with oral hygiene is often not sufficient to disease control. Recent studies of this condition have shown beneficial effects of auxiliary therapies or adjuncts such as the administration of systemic and locally antimicrobials. Among the local adjuncts, the literature presents antiseptics, antibiotics and photodynamic therapy. Antibiotics and anti-inflammatory represent systemic adjuncts. Regardless of the results presented by each of them, the difficulty of establishing a single protocol for all cases is recognized depending on the individual response shown by each patient. The aim of the present study was to review the current results about chemical adjuncts administration associated with conventional treatment in cases of aggressive periodontitis and suggest clinical protocols.

A periodontite agressiva, uma entidade clínica distinta da doença periodontal, é caracterizada por uma pronunciada destruição episódica e rápida dos tecidos periodontais e pode resultar em perda rápida e precoce dos dentes. Alguns trabalhos têm mostrado que o debridamento mecânico convencional juntamente com higiene oral muitas vezes não é suficiente para o controle da doença. Apesar de não existir consenso, estudos recentes desta condição mostram efeitos benéficos de terapias auxiliares ou coadjuvantes como a administração de antimicrobianos sistêmicos e locais. Entre os coadjuvantes locais, a literatura apresenta os antissépticos, antibióticos e terapia fotodinâmica. Dentre os sistêmicos são representados os antibióticos e antiinflamatórios. Independentemente dos resultados apresentados por cada um deles, se reconhece a dificuldade em se estabelecer um protocolo único para todos os casos em função da resposta individual apresentada por cada paciente. O objetivo do presente estudo foi revisar os resultados atuais sobre administração de coadjuvantes químicos associados à terapia convencional em casos de periodontite agressiva e sugerir protocolos clínicos.

Inter-relação entre doença periodontal e doenças de Alzheimer / nter-relationship between periodontal disease and Alzheimer’s disease – literature review

Atualmente, a Periodontia tem direcionado seus estudos na busca de uma inter-relação entre doença periodontal (DP) e os possíveis agravos à saúde sistêmica. O princípio da medicina periodontal postula que periodontopatógenos, mediadores inflamatórios e enzimas envolvidas na dinâmica da DP não se limitam à cavidade oral e podem causar quadros infeciosos e inflamatórios à distância. O papel da periodontite como um risco comum e/ou indicador de risco para várias doenças sistêmicas é amplamente aceito, e nesse contexto é que se embasa sua correlação ao início e progressão da doença de Alzheimer (DA). Dados epidemiológicos, microbiológicos e imunológicos indicam que patógenos periodontais frente a uma resposta imunoinflamatória hiper-reativa, determinada por uma predisposição genética, podem contribuir para uma inflamação neural e desenvolvimento da DA. Diante disso, o objetivo deste trabalho foi analisar, na literatura científica, evidências da associação entre DA e DP, utilizando as bases de dados Pubmed, Cochrane, Lilacs e Scielo, abrangendo estudos publicados nos últimos cinco anos.

Influence of periodontal biotype on buccal bone remodeling after tooth extraction using the flapless approach with a xenograft: a histomorphometric and fluorescence study in small dogs.

BACKGROUND: Several approaches have been used to counteract alveolar bone resorption after tooth extraction. PURPOSE: The aim of the present study was to evaluate the influence of gingival thickness and bone grafting on buccal bone remodeling in extraction sockets with thin buccal bone, using a flapless approach. MATERIALS AND METHODS: The gingiva of 8 dogs was thinned at one side of the mandible and mandibular premolars were extracted without flaps. The sockets were randomly assigned to the test group (thin gingiva) (TG), the test group with grafting material TG + GM, the control group (normal gingiva) (CG), or the control group with grafting material CG + GM. Ground sections were prepared from 12-week healing biopsies, and histomorphometry and fluorescence analysis were performed. RESULTS: In the groups with thin gingiva, numerically greater buccal bone loss was observed, while there were no differences between grafted and nongrafted sites. A numerically higher rate of mineralization was observed for the grafted sites, as compared with the nongrafted sites, at 12 weeks. CONCLUSIONS: A thin buccal bone plate leads to higher bone loss in extraction sockets, even with flapless surgery. The gingival thickness or the use of a graft material did not prevent buccal bone resorption in a naturally thin biotype, but modified the mineralization process.

Fatores mecânicos e cirúrgicos relacionados com mudanças do nível da crista óssea alveolar ao redor de implantes dentários: onde estamos? / Mechanical and surgical factors related to changes in the level of the alveolar crest around dental implants: where are we?

A manutenção de níveis estáveis do osso marginal e a verdadeira razão para a perda óssea peri-implantar permanecem altamente controversas. A remodelação óssea inicial pode ser influenciada pelo trauma cirúrgico, sobrecarga oclusal, peri-implantite, microgap, procedimentos com ou sem retalho e formação de distância biológica. A utilização de diferentes tipos de plataforma influencia os níveis de reabsorções ósseas peri-implantares, sendo recomendadas distâncias mínimas entre dente/implante e implante/implante para que ocorra preservação do osso adjacente. Tal fator influencia os tecidos moles ao redor dos implantes, interferindo positivamente ou negativamente na estética peri-implantar. Diante disso, foi realizada uma revisão nas bases de dados PubMed, Cochrane, Lilacs e SciELO, utilizando-se como unitermos de pesquisa os termos “implantes dentários” (dental implants), “processo alveolar” (alveolar process), “processos mecânicos” (mechanical processes) e “procedimentos cirúrgicos operatórios” (operative surgical procedures). Após avaliação sob os critérios de inclusão, selecionou-se 30 artigos, os quais englobaram revisões sistemáticas e metanálises, revisões da literatura, estudos clínicos e pré-clínicos. Apesar da literatura afirmar que uma perda óssea vertical de até 2 mm após a instalação do implante é esperada após a remodelação, esta perda pode ser minimizada controlando os fatores mecânicos e cirúrgicos durante as cirurgias de instalação de implantes.

The maintenance of stable marginal bone levels and the real reason behind the peri-implant bone loss are highly controversial. The early bone remodeling can be influenced by surgical trauma, occlusal overload, peri-implantitis, the microgap at the implant-abutment interface, flap or flapless procedures, and the formation of the biologic width. The use of different platform types influences on peri-implant bone resorption levels, being that minimum distances between tooth/implant and between dental implants are recommended to preserve the adjacent bone tissue. Such factor can influence the peri-implant soft tissues and interfere or not with the final outcomes. To verify this a review was made at the PubMed, Cochrane, SciELO, and Lilacs electronic databases with the terms “dental implants”, “alveolar process”, and “surgical procedures”. After inclusion criteria, 30 articles were selected, involving meta-analyses and systematic reviews, literature reviews, clinical and pre-clinical studies. Although there will be a vertical, 2 mm bone loss after implant placement and remodeling, this loss can be minimized controlling the surgical and mechanical factors on dental implant surgery.

Comparação de duas técnicas cirúrgicas para recobrimento radicular com matriz dérmica porcina / Comparison of two surgical techniques for root coverage using a new porcine collagen matrix

As retrações gengivais são um problema comum na população mundial, gerando transtornos estéticos e funcionais. Dentre as diversas técnicas cirúrgicas disponíveis, aquelas que utilizam enxertos de tecido conjuntivo subepitelial (ETCS) possuem a maior previsibilidade. No entanto, o uso deste enxerto autógeno pode não ser aceito por muitos pacientes, devido à necessidade de uma segunda área operatória, além de aumentar o tempo cirúrgico e possivelmente a morbidade. Assim, substitutos para o ETCS têm sido desenvolvidos para aumentar a aceitação destes procedimentos, objetivando tornar as cirurgias mais rápidas e com maior taxa de sucesso. O objetivo deste trabalho foi comparar e mostrar os benefícios da técnica de retalho estendido em relação à técnica de retalho avançado coronalmente. Através do modelo de boca dividida, foram operados 20 pacientes com retrações gengivais, Classe I ou II de Miller, maiores que 3 mm. Após três meses, obteve-se recobrimento de 60% (grupo-controle) e 82% (grupo-teste).

Palatal Harvesting Technique Modification for Better Control of the Connective Tissue Graft Dimensions

Subepithelial connective tissue graft (SCTG) has been extensively used for a variety of clinical applications. However, the surgical procedure may not allow control of graft thickness. The purpose of this case series is to illustrate a modification to the single incision palatal harvesting technique in order to control the SCTG thickness without increasing patient discomfort. Fifty cases from thirty systemically and periodontally healthy patients with at least one multiple gingival recession were treated with coronally advanced flaps combined with a SCTG. The palatal area served as the donor site, from where a single perpendicular incision was made to obtain a full thickness flap. Next, 1-2 mm of the flap was elevated and dissected to obtain a partial thickness flap. The graft remained attached to the full-partial thickness flap. After determining the desired SCTG thickness, the graft was harvested from the palatal flap. The patients healed uneventfully at 7 days postoperatively and primary closure was obtained for all palatal donor sites. The SCTG length and width varied depending on the needs of each case, but the SCTG thickness was well controlled with only 0.24 mm standard deviation. The suggested modification granted control of the SCTG dimensions and achieved complete wound closure within a week.

O enxerto de tecido conjuntivo (ETC) tem sido amplamente utilizado para várias aplicações clínicas. Entretanto, o procedimento cirúrgico pode não permitir o controle da espessura do enxerto gengival. O objetivo deste relato de casos seriados é descrever uma nova técnica cirúrgica que modifica a técnica de incisão única para remoção de enxerto gengival, permitindo o controle da espessura do ETC sem aumentar o desconforto do paciente. Cinquenta casos foram realizados em trinta pacientes sistemicamente e periodontalmente saudáveis, que apresentavam pelo menos uma retração gengival múltipla, a qual foi tratada pela técnica de retalho avançado coronalmente combinada com ETC. O palato serviu como área doadora, uma incisão perpendicular foi realizada para criar um retalho total. Em seguida 1-2 mm do retalho foi elevado e dissecado para obter um retalho parcial. O ETC permaneceu retido no retalho total-parcial. Depois de determinar qual a espessura desejada do ETC, o enxerto foi removido do palato. Os pacientes apresentaram cicatrização sem complicações em 7 dias, com fechamento da ferida por primeira intenção em todos os casos. A largura e comprimento do ETC variaram conforme a necessidade de cada caso clínico, mas a espessura do ETC foi bem controlada, com apenas 0,24 mm de desvio padrão. A sugestão de modificação de técnica cirúrgica para remoção de ETC permite controlar as dimensões do ETC e fechamento da ferida por primeira intenção em 7 dias.

Morphological, Functional and Biochemical Characterization of Canine Gingival Fibroblasts

As dogs are good models for in vivo studies, it is interesting to evaluate the behavior of canine gingival fibroblasts (CGF) in vitro, so that these cells could be seeded on a matrix and later studied in vivo. The aim of this study was to perform a morphological, functional and biochemical analysis of CGF, comparing it with human gingival fibroblasts (HGF), as well as to evaluate the change of their characteristics over several passages. Using gingival fibroblasts from 3 dogs and 3 humans in the subculture (Sub), first (P1), third (P3), fifth (P5) and seventh (P7) passages, the following parameters were assessed: cell morphology, spreading, adhesion, viability and total protein content. The results showed no major differences between the passages in terms of morphology and spreading, and a tendency of greater adhesion and viability for HGF when compared with CGF. The total protein content was significantly higher for HGF. HGF exhibited greater functional and biochemical activity in vitro compared to CGF. Higher numbers at Sub were observed for both CGF and HGF in all evaluated parameters. The differences do not prevent the use of CGF for tissue engineering, but its use seems to be more appropriate in the subculture or first passage.

Resumo Como os cães são um bom modelo para estudos in vivo, é interessante avaliar o comportamento de fibroblastos gengivais de cão (CGF) in vitro, para que essas células possam ser cultivadas em uma matriz e estudadas in vivo posteriormente. O objetivo do presente estudo foi realizar uma análise morfológica, funcional e bioquímica de CGF, comparando-os a fibroblastos gengivais humanos (HGF), bem como avaliar as alterações dessas características ao longo de várias passagens. Usando fibroblastos gengivais de 3 cães e 3 indivíduos na subcultura (Sub), primeira (P1), terceira (P3), quinta (P5) e sétima (P7) passagens, os seguintes parâmetros foram avaliados: morfologia, espraiamento, adesão, viabilidade e conteúdo de proteína total. Os resultados mostraram não haver diferenças significativas quanto à morfologia e espraiamento, e uma tendência a maior adesão e viabilidade para HGF, quando comparados a CGF. O conteúdo de proteína total foi significativamente maior para HGF. HGF exibiram maior atividade funcional e bioquímica in vitro quando comparados a CGF. Maiores valores na Sub foram observados para ambos, CGF e HGF, em todos os parâmetros avaliados. As diferenças não impedem o uso de CGF na engenharia tecidual, contudo, seu uso é mais apropriado na subcultura ou primeira passagem. .

Terapia fotodinâmica antimicrobiana (TFDa) aplicada à periodontia / Antimicrobial photodynamic therapy (TFDa) applied to Periodontology – a review

O objetivo do tratamento periodontal é o restabelecimento da saúde do periodonto a partir da remoção dos redutos bacterianos presentes na superfície radicular. Seu sucesso depende da eliminação dos agentes que promovem a destruição dos tecidos periodontais. No entanto, a terapia mecânica é limitada em remover os patógenos periodontais devido à habilidade de alguns microrganismos em invadir o interior dos tecidos, tornando a bolsa inacessível aos instrumentos periodontais, além de servir como foco de reinfecção. Deste modo, a busca por métodos coadjuvantes ao tratamento periodontal tem aumentado nos últimos tempos. Constitui propósito do presente estudo apresentar uma revisão da literatura sobre o efeito da terapia fotodinâmica antimicrobiana (TFDa) nos patógenos periodontais. A análise da literatura demonstrou que a TFDa mostrou-se eficaz na redução bacteriana, inclusive das bactérias periodontopatogênicas, apresentando-se como um coadjuvante promissor à terapia periodontal básica. Embora existam evidências científicas desses achados, novos estudos devem ser realizados para se determinar parâmetros específicos do laser e do agente fotossensitizador, capazes de tornar a TFDa mais efetiva e previsível.

Enxerto gengival livre e retalho posicionado coronariamente para recobrimento radicular / Free gingival grafts and coronally positioned flap for root coverage

O sucesso do tratamento das retrações gengivais baseia-se no conhecimentode sua etiologia e na avaliação da previsibilidade do recobrimentoradicular. Diversas técnicas têm sido propostas para o tratamento das retraçõesgengivais, a fim de promover possíveis melhorias na estética dosorriso. Este artigo relata um caso clínico de recobrimento radicular deretrações Classe I de Miller por meio do reposicionamento coronal do retalhoapós a colocação do enxerto gengival livre, tendo como resultado osucesso clínico do procedimento, tanto do ponto de vista do recobrimentoradicular como da satisfação da paciente.

Matriz dérmica acelular e matriz derivada do esmalte para recobrimento radicular em fumantes / Acellular dermal matrix grafts and enamel matrix protein for root coverage in smokers

O fumo apresenta uma influência negativa na previsibilidade dos procedimentos de cirurgias plásticas periodontais, principalmente, por meio da deficiência na função de fibroblastos periodontais. A literatura relata bons resultados clínicos de recobrimento radicular com o uso da matriz dérmica celular (MDA) e que a proteína derivada da matriz do esmalte (PDME) contribui para a melhora na atividade fibroblástica. O objetivo desse estudo foi avaliar a MDA associada ou não à PDME para recobrimento radicular em fumantes. Foram selecionados 20 pacientes com retrações gengivais bilaterais Classe I ou II de Miller, > 3 mm. Um grupo foi tratado com MDA e o outro com MDA associada à PDME. Os parâmetros clínicos - profundidade de bolsa a sondagem (PBS), nível clínico de inserção relativo (NCIR), altura da retração gengival (ARG), largura da retração gengival (LRC), quantidade de gengiva queratinizada (QCQ) e espessura da gengiva queratinizada (EGQ) - foram avaliados duas semanas após a terapia períodontal básica (exame inicial) e três meses após os procedimentos cirúrgicos. Par análise estatística, foram usados os testes de Wilcoxon, com nível de significância de 5%. Os dois procedimentos apresentaram resultados favoráveis, com diferenças estatisticamente significantes em todos os parâmetros clínicos após três meses. Não houve diferenças estatisticamente significantes entre os grupos. Concluiu-se que a MDA associada ou não à PMDE pode ser uma alternativa para o recobrimento radicular de retrações gengivais Classe I e II de Miller. Contudo, em pacientes fumantes, a associação da PMDE à MDA parece não mostrar benefícios clínicos adicionais no recobrimento radicular três meses após a cirurgia.

Periodontal disease: a genetic perspective.

Periodontitis is a multifactorial disease that causes tooth loss. The complex pathogenesis of periodontitis implies the involvement of a susceptible host and a bacterial challenge. Many studies have provided a valuable contribution to understanding the genetic basis of periodontal disease, but the specific candidate genes of susceptibility are still unknown. In fact, genome-wide studies and screening of single-nucleotide polymorphisms have yielded new genetic information without a definitive solution for the management of periodontal disease. In this manuscript, we provide an overview of the most relevant literature, presenting the main concepts and insights of the strategies that have been emerging to better diagnose and treat periodontal disease based on biomarker analysis and host modulation.