Absence of medication-related jaw osteonecrosis after treatment with strontium ranelate in ovariectomized rats.

This study aimed to evaluate the potential of strontium ranelate (SR) in medication-related jaw osteonecrosis (MRONJ) after tooth extraction in ovariectomized rats. Thirty ovariectomized rats were divided into three groups (n = 10): bisphophonate (BP) group (zoledronic acid; 0.4 mg/kg/week), SR group (625 mg/kg/day), and control group (saline solution). The lower first molars were extracted after 60 days of drug therapy. Drug administration was continued for another 30 days after tooth extraction. The mandibles were subjected to clinical, histological, radiographic, and microtomographic evaluations. Only the BP group showed clinical changes, characterized by the presence of 70% (n = 7) and 20% (n = 2) of ulcers and extraoral fistulas. Radiographic evaluation demonstrated bone sequestration only in the BP group (n = 7, 70%). Microtomographic analysis revealed increased bone porosity after ovariectomy, particularly in the the control group (p < 0.05). The BP group showed a higher bone surface density, bone volume, and trabecular number than SR and control groups, but with less trabecular separation (p < 0.05). All the animals in the BP group demonstrated histological osteonecrosis. There was no evidence of osteonecrosis in the control and SR groups, which was characterized by the absence of empty osteocyte gaps and associated with the gradual healing of the extraction area. Also, an increased number of blood vessels and a reduced number of osteoclasts were observed in the SR group (p < 0.05). Therefore, SR treatment increased angiogenesis and osteoclastogenesis in the healing socket and was not associated with MRONJ development after tooth extraction in ovariectomized rats.

Absence of medication-related jaw osteonecrosis after treatment with strontium ranelate in ovariectomized rats

Abstract This study aimed to evaluate the potential of strontium ranelate (SR) in medication-related jaw osteonecrosis (MRONJ) after tooth extraction in ovariectomized rats. Thirty ovariectomized rats were divided into three groups (n = 10): bisphophonate (BP) group (zoledronic acid; 0.4 mg/kg/week), SR group (625 mg/kg/day), and control group (saline solution). The lower first molars were extracted after 60 days of drug therapy. Drug administration was continued for another 30 days after tooth extraction. The mandibles were subjected to clinical, histological, radiographic, and microtomographic evaluations. Only the BP group showed clinical changes, characterized by the presence of 70% (n = 7) and 20% (n = 2) of ulcers and extraoral fistulas. Radiographic evaluation demonstrated bone sequestration only in the BP group (n = 7, 70%). Microtomographic analysis revealed increased bone porosity after ovariectomy, particularly in the the control group (p < 0.05). The BP group showed a higher bone surface density, bone volume, and trabecular number than SR and control groups, but with less trabecular separation (p < 0.05). All the animals in the BP group demonstrated histological osteonecrosis. There was no evidence of osteonecrosis in the control and SR groups, which was characterized by the absence of empty osteocyte gaps and associated with the gradual healing of the extraction area. Also, an increased number of blood vessels and a reduced number of osteoclasts were observed in the SR group (p < 0.05). Therefore, SR treatment increased angiogenesis and osteoclastogenesis in the healing socket and was not associated with MRONJ development after tooth extraction in ovariectomized rats.

Are neutrophil extracellular traps the link for the cross-talk between periodontitis and rheumatoid arthritis physiopathology?

OBJECTIVES: Neutrophil extracellular traps (NETs) play a role in the pathogenesis of periodontitis and rheumatoid arthritis (RA). However, it remains poorly understood whether NETs participate in the cross-talk between periodontitis and RA. Herein, we investigated the production of NETs in individuals with periodontitis and RA and its association with clinical parameters. The impact of periodontal therapy on RA and NET release was also assessed. METHODS: The concentration of NETs and cytokines was determined in the saliva and plasma of individuals with early RA (n = 24), established RA (n = 64) and individuals without RA (n = 76). The influence of periodontitis on the production of NETs and cytokines was also evaluated. RESULTS: Individuals with early RA had a higher concentration of NETs in saliva and plasma than individuals with established RA or without RA. Periodontitis resulted in an increase in the concentration of NETs of groups of individuals without RA and with early RA. The proportion of individuals with high concentrations of IL-6, IL-10 and GM-CSF was higher among individuals with periodontitis than among individuals without periodontitis. The concentrations of TNF-α, IL-6, IL-17/IL-25 and IL-28A were particularly high in individuals with early RA. Worse periodontal clinical parameters, RA onset and RA activity were significantly associated with circulating NETs. Periodontal therapy was associated with a reduction in the concentration of NETs and inflammatory cytokines and amelioration in periodontitis and RA. CONCLUSION: This study reveals that NETs are a possible link between periodontitis and RA, with periodontal therapy resulting in a dramatic switch in circulating NET levels.

Caprine demineralized bone matrix (DBMc) in the repair of non-critical bone defects in rabbit tibias. A new bone xenograft.

PURPOSE: To evaluate the use of demineralized bone matrix of caprine origin in experimental bone defects of the tibia in New Zealand rabbits. METHODS: Fragments of the tibia diaphysis were collected aseptically from clinically healthy goats. The bones were sectioned into 1 cm fragments and stored at -20°C for subsequent hydrochloric acid (HCL) demineralization. A 70 mg portion of DBMc was used to fill the experimental bone defects. Twenty-four female adult New Zealand rabbits were divided into 2 groups: the MG (matrix group, left tibia) and CG (control group, right tibia). Additionally, they were separated into 4 groups with 6 animals, according to the period of analysis (15, 30, 60 and 90 days postoperatively). Using microCT, volumetric parameters were evaluated: bone volume, relationship between bone volume and total volume, bone surface area, relationship between bone surface area and total volume, number of trabeculae, trabecular thickness and trabecular separation. RESULTS: There was a statistically significant difference (P<0.05) between groups considering bone volume (BV) and bone:total volume (BV/TV), on 15, 30 and 90 days postoperatively. Control group showed a statistically significant superiority (P < 0.05) considering the mean of the variables bone surface (BS), number of trabeculae (Tb.N) and between bone surface and total volume (BS/TV) at 15 and 90 days. CONCLUSIONS: Caprine demineralized bone matrix was safe and tolerable. No signs of material rejection were seen macroscopically. It is an alternative for the treatment of bone defects when autologous graft is not available or in insufficient quantities.

Influence of collagen membrane on bone quality in titanium mesh reconstructions-Study in rats.

BACKGROUND: New bone formation and tissue remodeling are the major challenges in implantology today. Titanium meshes have demonstrated reconstructive potential for vertical bone gain. However, the soft tissue healing is technically sensitive to the surgical procedure. The combined usage of collagen membrane and specification of the meshes may ensure greater predictability. Therefore, this study aims to evaluate the influence of collagen membrane on the quality of the new bone formation in guided bone regeneration (GBR) procedures with different titanium meshes. METHODS: Twenty-eight Wistar rats were randomly allocated into four main experimental groups, according to mesh pore size in µm: Group P300 (titanium meshes, with 0.3-mm thickness and 3-mm pore size; n = 7); Group P175 (titanium meshes, with 0.3-mm thickness and 1.75-mm pore size; n = 7); Group P85: (titanium meshes, with 0.04-mm thickness and 0.85-mm pore size; n = 7); Group P15: (titanium meshes. with 0.04-mm thickness and 0.15-mm pore size; n = 7). The femurs of each animal were subdivided into test and control groups: Test: bovine bone graft associated with porcine collagen and collagen membrane was used; control: bovine bone graft associated with porcine collagen was used without association with collagen membrane. Bone quality evaluation by in vivo microtomography and histologic analysis were performed. RESULTS: Bone volume formation was similar between groups (P >0.05). However, the titanium meshes with pore size >1 mm demonstrated higher mineral bone density in comparison with meshes with pore size <1 mm (P <0.05), regardless of the combined usage of collagen membrane. All groups showed a spongy bone formation after 30 days. CONCLUSIONS: Combined usage of collagen membrane in GBR procedures with titanium mesh did not show improvements in new bone quality in rat femur model. However, titanium mesh pore size specifications may influence bone quality.

Caprine demineralized bone matrix (DBMc) in the repair of non-critical bone defects in rabbit tibias. A new bone xenograft

Abstract Purpose To evaluate the use of demineralized bone matrix of caprine origin in experimental bone defects of the tibia in New Zealand rabbits. Methods Fragments of the tibia diaphysis were collected aseptically from clinically healthy goats. The bones were sectioned into 1 cm fragments and stored at -20°C for subsequent hydrochloric acid (HCL) demineralization. A 70 mg portion of DBMc was used to fill the experimental bone defects. Twenty-four female adult New Zealand rabbits were divided into 2 groups: the MG (matrix group, left tibia) and CG (control group, right tibia). Additionally, they were separated into 4 groups with 6 animals, according to the period of analysis (15, 30, 60 and 90 days postoperatively). Using microCT, volumetric parameters were evaluated: bone volume, relationship between bone volume and total volume, bone surface area, relationship between bone surface area and total volume, number of trabeculae, trabecular thickness and trabecular separation. Results There was a statistically significant difference (P<0.05) between groups considering bone volume (BV) and bone:total volume (BV/TV), on 15, 30 and 90 days postoperatively. Control group showed a statistically significant superiority (P < 0.05) considering the mean of the variables bone surface (BS), number of trabeculae (Tb.N) and between bone surface and total volume (BS/TV) at 15 and 90 days. Conclusions Caprine demineralized bone matrix was safe and tolerable. No signs of material rejection were seen macroscopically. It is an alternative for the treatment of bone defects when autologous graft is not available or in insufficient quantities.

Preservação de alvéolo com uso de enxerto ósseo particulado e matriz de colágeno suíno: revisão de literatura e relato de caso clínico / Ridge preservation using particulate bone graft and Matrix of porcine collagem: Literature Review and clinical case report

Para tentar preservar as dimensões teciduais (ósseas e de tecido mole) do alvéolo até o momento da instalação do implante pode-se lançar mão de técnicas de preservação de alvéolos dentários imediatamente após a exodontia. Dentre as diversas técnicas e biomateriais existentes, a associação de um substituto ósseo (Bio-Oss® Collagen) com um selador do alvéolo (Mucograft® Seal) vem apresentando resultados satisfatórios na literatura. O objetivo do presente trabalho é apresentar uma breve revisão de literatura e um relato de caso clínico usando essa abordagem. Os principais achados da revisão de literatura é que a utilização desses substitutos mucosos e ósseos são a redução do tempo cirúrgico e diminuição da morbidade e desconforto pós-operatório do paciente, já que não necessita da área doadora. No relato de caso, os resultados clínicos de 15 e 60 dias de pós-operatório mostraram que essa abordagem foi eficaz em manter as dimensões ósseas e de tecido queratinizado do alvéolo. (AU)

In an effort to preserve the alveolar tissue dimensions (bone and soft tissue) until the time of implant installation can make use of ridge preservation techniques after the dental extraction. Among the many techniques and biomaterials the association of a bone substitute (Bio-Oss® Collagen) with an alveolar sealer (Mucograft® Seal) has shown satisfactory results in the literature.The objective of this study is present a brief literature review and a clinical case report using this approach. The main findings of the literature review are that the use of these mucosal and bone substitutes are the reduction of surgical time and decrease of the postoperative morbidity and discomfort of the patient, since it does not need the donor area. In the case reportthe clinical results of 15 and 60 days postoperatively showed that this approach was effective in maintaining bone dimensions and keratinized alveolar tissue (AU)

Uso da matriz derivada do esmalte (mde) associada ao vidro bioativo no tratamento de defeitos infra-ósseos: uma revisão de literatura / Use of enamel matrix derivate (EMD) associated with bioactive glass in the treatment of intraosseous defects: A Literature Review

A regeneração periodontal tem como objetivo recuperar as estruturas perdidas (osso alveolar, cemento e ligamento periodontal) como sequelas da doença periodontal. O conhecimento da Matriz Derivada do Esmalte (MDE) tem na literatura uma ampla aplicação, porém sua relação direta associada aos vidros bioativos é pouco caracterizada em todas suas vias, nesse contexto este estudo teve como proposta baseada numa revisão literária por meio de bases de dados (Pubmed, Scielo, lilacs), discutir aspectos importantes sobre a avaliação da efetividade clínica do vidro bioativo em combinação com a MDE (Emdogain) principalmente em defeitos infra-ósseos. O Emdogain (EMD) sozinho ou em associação a outros biomaterais de enxertia parece promover ganhos na regeneração tecidual de tecidos perdidos pela periodontite, porém sua associação tem-se poucos resultados significativos que justifiquem sua ampla utilização, sua indicação deve estar baseada em um bom diagnóstico periodontal e da morfologia do defeito infraósseo. Assim, tornam-se necessários mais estudos para elucidar interações e mecanismos celulares envolvidos no complexo de ação para justificar o seu uso.(AU)

Periodontal regeneration aims to recover the lost structures (alveolar bone, cementum and periodontal ligament) as sequelae of periodontal disease. The knowledge derived from the enamel matrix (EMD) is in the literature a wide application, but its direct relationship associated with bioactive glass is poorly characterized in all its way in this context this study was proposed based on a literature review through databases (Pubmed, Scielo, lilacs), discuss important aspects of the evaluation of the clinical effectiveness of bioactive glass in combination with EMD (Emdogain) mainly intraosseous defects.Emdogain (EMD) alone or in association with other biomaterials of grafting appears to promote gains in the tissue regeneration of lost tissues by periodontitis, but its association has few significant results that justify its wide use, its indication must be based on a good periodontal diagnosis and infraosseous defect morphology. Thus, further studies are needed to elucidate interactions and cellular mechanisms involved in the action complex to justify its use.(AU)

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.

Tratamento de retrações gengivais múltiplas / Treatment of multiple gingival recessions

A retração gengival é o deslocamento da gengiva marginal apicalmente à junção amelocementária, sendo uma queixa frequente na rotina do consultório, pois geralmente apresenta aspecto antiestético e pode contribuir para a hipersensibilidade dentinária e cárie. Miller (1985) propôs a classificação das recessões gengivais em classes I, II, III e IV, em que os melhores prognósticos de recobrimento estão associados às classes I e II. A escolha do procedimento cirúrgico apropriado irá depender de fatores como: altura da recessão, perda óssea interproximal, quantidade e qualidade de gengiva queratinizada, número de dentes envolvidos e largura de tecido interdental. Quando a gengiva é fina, o biotipo delgado associa-se o enxerto de tecido conjuntivo ao retalho posicionado coronalmente. O enxerto de tecido conjuntivo tem por objetivo aumentar a espessura do tecido queratinizado e o prognóstico do recobrimento radicular. Porém, na técnica convencional de retalho posicionado coronalmente pode ocorrer prejuízo de tecido queratinizado interdental. Diante disso, Zucchelli e De Sanctis (2000) propuseram uma técnica alternativa para os casos de recessões múltiplas em que papilas cirúrgicas são criadas através de incisões oblíquas, evitando a perda de tecido queratinizado interdental. O objetivo deste trabalho foi relatar um caso clínico bem-sucedido de tratamento de recessões gengivais múltiplas classe I e II de Miller, utilizando a técnica de Zucchelli e De Sanctis associada a enxerto de tecido conjuntivo, sendo o dente 13 eleito como referência para iniciar as incisões. Após 90 dias, pôde-se perceber o total recobrimento e melhor qualidade do tecido periodontal.

Gingival recession is a displacement of the marginal gingiva apical to the cemento enamel junction and a common complaint in clinical practice, because it usually is unaesthetic and can lead to dentin hypersensitive and caries. Miller (1985) proposed the classification of gingival recession in class I, II, III and IV, and better outcomes are associated to classes I and II. Selection of the appropriate surgical technique will depend on the factors: recession height, interdental bone loss, quantity and quality of keratinized gingiva, number of teeth, and width of interdental tissue. In cases of thin gingiva biotype, connective tissue graft associated with coronally positioned flap is indicated. The use of connective tissue graft aim to increase keratinized tissue thickness and the prognosis of root coverage. Nevertheless, in the traditional technique of coronally positioned flap may occur interdental keratinized tissue loss. Therefore, Zucchelli and De Sanctis (2000) proposed a technique for the treatment of multiple recessions, witch surgical papilla are perfomal through oblique incisions to avoid loss of interdental keratinized tissue. The aim of this paper is report a clinical case of Miller class I and II gingival recession treatment, using Zuchelli e De Sanctis technique associated with connective tissue graft, initial incisions was made as a reference in the upper right canine. After 90 days, complete root coverage and periodontal tissue improvement were visible.

Histologic and Histometric Analysis of Bone Repair at the Site of Mandibular Body Osteotomy and at the Bone-Screw Interface After Using a Biodegradable 2.0-mm Internal Fixation System.

The aim of the study was to evaluate histologically and histometrically the bone repair at the mandibular body osteotomy and at the bone-screw interface after using a biodegradable 2.0-mm internal fixation system. Six dogs were subjected to an osteotomy in the mandibular body, which was stabilized by applying a fixation device manufactured with poly-L-DL-lactic acid (70:30). The dogs were euthanized at 2 and 18 weeks. Each screw was sectioned along its long axis, and the osteotomy sites were divided into 3 parts: the upper part was labeled the tension third (TT); the lower part, compression third (CT); and the part between the TT and CT, intermediary third (IT). Histologic analysis showed areas of direct contact between the screw surface and the parent lamellar bone at 2 weeks. At 18 weeks, 3 microscopically distinct layers at the bone-screw interface were noted. At the osteotomy sites, union between the bone fragments was observed at 18 weeks. Statistically significant differences in the newly formed bone among TT, IT, and CT (P = 0.019) were observed. In conclusion, the biomechanical environment created by the biodegradable IF system used in this study facilitated bone repair at the osteotomy site.

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.

Expression of osteoblastic phenotype in periodontal ligament fibroblasts cultured in three-dimensional collagen gel.

OBJECTIVE: To investigate the influence of a three-dimensional cell culture model on the expression of osteoblastic phenotype in human periodontal ligament fibroblast (hPDLF) cultures. MATERIAL AND METHODS: hPDLF were seeded on bi-dimensional (2D) and three-dimensional (3D) collagen type I (experimental groups) and and on a plastic coverslip (control) for up to 14 days. Cell viability and alkaline phosphatase (ALP) activity were performed. Also, cell morphology and immunolabeling for alkaline phosphatase (ALP) and osteopontin (OPN) were assessed by epifluorescence and confocal microscopy. The expression of osteogenic markers, including alkaline phosphatase, osteopontin, osteocalcin (OC), collagen I (COL I) and runt-related transcription factor 2 (RUNX2), were analyzed using real-time polymerase chain reaction (RT-PCR). Mineralized bone-like nodule formation was visualized by microscopy and calcium content was assessed quantitatively by alizarin red assay. RESULTS: Experimental cultures produced an increase in cell proliferation. Immunolabeling for OPN and ALP in hPDLF were increased and ALP activity was inhibited by three-dimensional conditions. OPN and RUNX2 gene expression was significantly higher on 3D culture when compared with control surface. Moreover, ALP and COL I gene expression were significantly higher in three-dimensional collagen than in 2D cultures at 7 days. However, at 14 days, 3D cultures exhibited ALP and COL I gene expression significantly lower than the control, and the COL I gene expression was also significantly lower in 3D than in 2D cultures. Significant calcium mineralization was detected and quantified by alizarin red assay, and calcified nodule formation was not affected by tridimensionality. CONCLUSION: This study suggests that the 3D cultures are able to support hPDLF proliferation and favor the differentiation and mineralized matrix formation, which may be a potential periodontal regenerative therapy.

Expression of osteoblastic phenotype in periodontal ligament fibroblasts cultured in three-dimensional collagen gel

Objective : To investigate the influence of a three-dimensional cell culture model on the expression of osteoblastic phenotype in human periodontal ligament fibroblast (hPDLF) cultures. Material and Methods : hPDLF were seeded on bi-dimensional (2D) and three-dimensional (3D) collagen type I (experimental groups) and and on a plastic coverslip (control) for up to 14 days. Cell viability and alkaline phosphatase (ALP) activity were performed. Also, cell morphology and immunolabeling for alkaline phosphatase (ALP) and osteopontin (OPN) were assessed by epifluorescence and confocal microscopy. The expression of osteogenic markers, including alkaline phosphatase, osteopontin, osteocalcin (OC), collagen I (COL I) and runt-related transcription factor 2 (RUNX2), were analyzed using real-time polymerase chain reaction (RT-PCR). Mineralized bone-like nodule formation was visualized by microscopy and calcium content was assessed quantitatively by alizarin red assay. Results : Experimental cultures produced an increase in cell proliferation. Immunolabeling for OPN and ALP in hPDLF were increased and ALP activity was inhibited by three-dimensional conditions. OPN and RUNX2 gene expression was significantly higher on 3D culture when compared with control surface. Moreover, ALP and COL I gene expression were significantly higher in three-dimensional collagen than in 2D cultures at 7 days. However, at 14 days, 3D cultures exhibited ALP and COL I gene expression significantly lower than the control, and the COL I gene expression was also significantly lower in 3D than in 2D cultures. Significant calcium mineralization was detected and quantified by alizarin red assay, and calcified nodule formation was not affected by tridimensionality. Conclusion : This study suggests that the 3D cultures are able to support hPDLF proliferation and favor the differentiation and mineralized matrix formation, which may be a potential periodontal regenerative therapy. .

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.

Levantamento do assoalho do seio maxilar – aspectos clínicos e de imagem / Maxillary sinus floor lifting – clinical and imaging aspects

Este artigo demonstra os recursos de imagens que contribuem para um diagnóstico e planejamento eficazes na execução previsível do procedimento cirúrgico de levantamento de assoalho de seio maxilar (ESM), um problema comumente encontrado na reabilitação posterior de maxila, limitando a instalação de implantes de comprimento médio (10 mm). Os procedimentos de elevação do assoalho do seio maxilar (ESM) são uma opção para a resolução desse problema. Atualmente, duas principais técnicas são utilizadas para ESM: a técnica atraumática, com a utilização de osteótomos e instalação simultânea de implantes; e a técnica de janela lateral, com ou sem instalação simultânea de implantes. A decisão da técnica a ser realizada é baseada na avaliação da quantidade óssea e na possibilidade de estabilidade primária dos implantes. Esse passo é realizado com o auxílio de exames de imagens bi e tridimensionais. Nos casos em que é necessária a utilização de enxertos, o osso autógeno é considerado o padrão-ouro. No entanto, a literatura também apresenta casos de sucesso utilizando substitutos ósseos e combinações com osso autógeno. Apesar da técnica já estar bem desenvolvida, algumas complicações podem ocorrer em procedimentos de ESM, como a perfuração da membrana sinusal, hemorragias, estabilidade primária do implante insuficiente, deslocamento do enxerto dentro do seio maxilar e exposição ou lesões de nervos...

This article highlights the imaging resources contributing to effective diagnosis and planning for elevation of the maxillary sinus floor (ESM), a common issue at the posterior region which prevents implant placement of 10 mm in length. ESM procedures can overcome this situation. Nowadays, two main techniques are available for ESM: the atraumatic technique, with the use of osteotomes and immediate implant placement, and the lateral window technique, with/without implant placement. Decisions are based on available bone quantity and primary implant stability. Also, bi- and three-dimensional imaging techniques are valuable tool in this process. When necessary, the autogenous bone is still the gold standard. However, there are reports of success with bone substitutes and combinations with autogenous material. Although well-developed, some complications occur with ESM procedures, as well as membrane perforation, hemorrhage, lack of primary implant stability, and graft displacement inside the maxillary sinus, exposure, and nerve damage...

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).

Alloderm e PepGen P-15 na reabilitação oral em um periodonto reduzido: acompanhamento de quatro anos / Alloderm and PepGen P-15 for oral rehabilitation in a patient with reduced periodontium: four years of follow-up

O objetivo deste relato foi analisar os resultados obtidos com a utilização da matriz dérmica acelular (MDA) e matriz óssea bovina inorgânica ligada ao peptídeo P-15 (MOI/P-15), para a preservação óssea alveolar após a extração dentária e posterior reabilitação com implantes, em uma paciente periodontalmente comprometida. Uma paciente do gênero feminino, que apresentava problemas periodontais severos nos elementos 11, 12, 21 e 22, recebeu tratamento periodontal básico. O planejamento do caso consistiu na remoção dos dentes condenados associada ao tratamento de preservação óssea do rebordo alveolar e subsequente reabilitação oral com implantes

The objective of this report was to analyze the results achieved with the use of acellular dermal matrix (ADM) with or without the inorganic bovine bone matrix (ABM) linked to cell binding peptide P-15 for socket preservation after tooth extraction and subsequent rehabilitation with dental implants of a periodontally compromised patient. A female patient who had a severe periodontal condition in the elements 11, 12, 21 and 22 received basic periodontal treatment. A surgical approach for this case included the removal of hopeless teeth and alveolar bone reservation. Subsequent rehabilitation with oral implants had been done

Considerações clínicas no planejamento e instalação de implantes imediatos / Clinical considerations for immediate implant placement and treatment planning

As reabilitações implantossuportadas permitem o restabelecimento da função e da estética após perdas dentárias totais e parciais com previsibilidade e altas taxas de sucesso. A instalação de implantes imediatos com carga imediata, a fim de evitar as alterações dimensionais sofridas pelo osso alveolar e tecidos moles, após a extração dentária, apresenta algumas vantagens em relação à técnica convencional, como redução do número de procedimentos cirúrgicos, possível preservação do osso alveolar, redução de custos e do período de ausência dentária, além de maior aceitação por parte do paciente. Vários estudos têm demonstrado que implantes instalados em alvéolos frescos e com carga imediata apresentam uma taxa de sobrevivência entre 94,5% a 100%. No entanto, para que um resultado funcional e estético adequado seja obtido, é fundamental que seja realizado um planejamento preciso, lançando mão dos recursos de diagnóstico bi e tridimensionais disponíveis, para que fatores relacionados à qualidade e à quantidade óssea sejam avaliados...

Dental implant-supported restorations present predictability and high success rates in restoring function and esthetics. The immediate placement/loading of dental implants is considered an option to reduce the risk of dimensional changes due to alveolar bone resorption and soft tissue collapse following tooth extraction. Other advantages over the conventional technique are the reduced number of surgical procedures, possible alveolar bone preservation, reduced costs, shorter period for temporary crowns or bridges, and greater acceptance by the patient. Several studies have shown that implants placed in fresh sockets with immediate loading have a high survival rate between 94.5 to 100%. However, for achieving a functional and aesthetic result, adequate treatment planning is fundamental including clinical and two- and three-dimensional diagnostic approaches...