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.

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.

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.

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.

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.

Crestal bone loss minimized when following the crestal preparation protocol: a histomorphometric study in dogs.

Initial breakdown of the implant-tissue interface generally begins at the crestal region in successfully osseointegrated implants. The purpose of this study was to evaluate the effect on crestal bone loss (CBL) around implants specially developed for immediate loading with a unique crestal drill. After 8 weeks postextraction, 6 young male mongrel dogs received 48 implants (XiVE) in the region corresponding to the 4 mandibular premolars. The implant sites were prepared according to the manufacturer's protocol with conventional standard drills. Before implant placement, the crestal drill was used in the experimental group but not in the control group. After a healing period of 12 weeks, the dogs were sedated and euthanized. Through linear measurements, from the top of the implant to the first bone-implant contact, the amount of CBL was determined. The histomorphometric results of CBL (mean +/- SEM) were 0.88 +/- 0.13 mm (range 0.0-3.0 mm) in the experimental group and 1.69 +/- 0.17 mm (range 0.0-4.2 mm) in the control group. The difference was statistically significant (P < .05) when the implants were used as the experimental units. The statistical analysis also revealed significance when the dogs were used as the experimental units (P < .05). When the median was used for analyses, the CBL was 0.44 mm for the experimental group and 1.91 mm for the control group. Crestal bone loss was minimized when the crestal preparation protocol was carefully followed by using the osseocondensating XiVE implant system.

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.

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.

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.

'Interleukin-4 gene polymorphism and its relation to periodontal disease in a Brazilian population of African heritage'.

OBJECTIVES: Host modifying factors, such as genetic predisposition, may increase severity of periodontitis. Genetic polymorphisms in interleukin-4 (IL-4) genes seem to influence host response to microbial challenge. Two IL-4 polymorphisms were found in association with asthma and atopy, and later with aggressive periodontitis in Caucasians. There seems to be a trend for racial differences regarding polymorphisms. Therefore, this study aimed to evaluate if these IL-4 polymorphisms were associated with periodontal disease in a Brazilian population of African heritage. METHODS: Sixty patients were divided into two groups: periodontitis group (n = 30) and control group (n = 30) Blood samples were taken and genomic DNA was amplified by polymerase chain reaction (PCR). Identification of 70 bp repeat polymorphism in intron 2 and in the -590 position of the promoter region was performed through PCR-RFLP and electrophoresis in agarose gel. RESULTS: No significant differences were found in the genotype frequency of the polymorphisms between control and periodontitis group. Chi square test and Mann-Whitney test were used for statistical analysis. CONCLUSIONS: We concluded that the studied IL-4 polymorphisms were not related to periodontal disease susceptibility in this African-American Brazilian population.

Histomorphometric analysis of rat alveolar wound healing with hydroxyapatite alone or associated to BMPs.

Several materials and techniques have been proposed to improve alveolar wound healing and decrease loss of bone height and thickness that normally follow dental extraction. The objective of this research was the histologic analysis of bone morphogenetic proteins implanted into dental alveoli of rats after extraction. A total of 45 adult male Wistar rats were divided into three groups of 15 animals each: control (no treatment), implanted with pure hydroxyapatite (HA, 3 mg) and implanted with hydroxyapatite plus bone morphogenetic proteins (HA/BMPs, 3 mg). Five animals from each group were sacrificed at 7, 21 and 42 days after extraction for the histometric analyses of the osteoconductive potential of hydroxyapatite associated or not with BMPs. After dissection, fixation, decalcification and serial microtomy of 6-micron thick sections, the samples were stained with hematoxylin-eosin for histologic and histometric analyses. Both HA and HA/BMPs caused a delay in wound healing compared to control animals, evaluated by the percentage of bone tissue in the alveoli. The treatment with HA/BMPs had the greatest delay at 21 days, even though it produced values similar to the control group at 42 days. The materials did not improve alveolar repair in the normal period of wound healing and the association of HA/BMPs did not have osteoconductive properties with granulated hydroxyapatite as the vehicle.

Use of acellular dermal matrix graft in the treatment of gingival recessions: a case report.

Case presentation in which a 12-years-old boy presented with two large gingival recessions on the maxillary central incisors, secondary to a lateral luxation. In the surgical procedure, an acellular dermal matrix graft (ADMG) was placed as a substitute for a free gingival graft. Twelve months later, complete root coverage was achieved, showing that ADMG, a biomaterial recently developed for mucogingival surgery, can be successfully used in the treatment of gingival recessions in pediatric patients.

Digital subtraction radiographic analysis of the combination of bioabsorbable membrane and bovine morphogenetic protein pool in human periodontal infrabony defects.

OBJECTIVES: This study assessed the bone density gain and its relationship with the periodontal clinical parameters in a case series of a regenerative therapy procedure. MATERIAL AND METHODS: Using a split-mouth study design, 10 pairs of infrabony defects from 15 patients were treated with a pool of bovine bone morphogenetic proteins associated with collagen membrane (test sites) or collagen membrane only (control sites). The periodontal healing was clinically and radiographically monitored for six months. Standardized pre-surgical and 6-month postoperative radiographs were digitized for digital subtraction analysis, which showed relative bone density gain in both groups of 0.034 ± 0.423 and 0.105 ± 0.423 in the test and control group, respectively (p>0.05). RESULTS: As regards the area size of bone density change, the influence of the therapy was detected in 2.5 mm² in the test group and 2 mm² in the control group (p>0.05). Additionally, no correlation was observed between the favorable clinical results and the bone density gain measured by digital subtraction radiography (p>0.05). CONCLUSIONS: The findings of this study suggest that the clinical benefit of the regenerative therapy observed did not come with significant bone density gains. Long-term evaluation may lead to a different conclusions.

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.

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.

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. .

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)