Photosensitizers attenuate LPS-induced inflammation: implications in dentistry and general health.

Antimicrobial photodynamic therapy (aPDT) is a complementary therapeutic modality for periodontal and endodontic diseases, in which Gram-negative bacteria are directly involved. Currently, there are few evidences regarding the effects of aPDT on bacterial components such as lipopolysaccharide (LPS) and it would represent a major step forward in the clinical use of this therapy. In this context, this study aimed to evaluate the efficacy of different photosensitizers (PSs) used in aPDT in LPS inhibition. Four PSs were used in this study: methylene blue (MB), toluidine blue (TBO), new methylene blue (NMB), and curcumin (CUR). Different approaches to evaluate LPS interaction with PSs were used, such as spectrophotometry, Limulus amebocyte lysate (LAL) test, functional assays using mouse macrophages, and an in vivo model of LPS injection. Spectrophotometry showed that LPS decreased the absorbance of all PSs used, indicating interactions between the two species. LAL assay revealed significant differences in LPS concentrations upon pre-incubation with the different PSs. Interestingly, the inflammatory potential of LPS decreased after previous treatment with the four PSs, resulting in decreased secretion of inflammatory cytokines by macrophages. In vivo, pre-incubating curcumin with LPS prevented animals from undergoing septic shock within the established time. Using relevant models to study the inflammatory activity of LPS, we found that all PSs used in this work decreased LPS-induced inflammation, with a more striking effect observed for NMB and curcumin. These data advance the understanding of the mechanisms of LPS inhibition by PSs.

Prosthetically Driven Alveolar Reconstructions: A Retrospective Study.

This study aims to evaluate the post-extraction alveolar bone reconstruction amongst 12 patients exhibiting loss of buccal bone plate in a tooth of the anterior region of the maxilla using the prosthetically-driven alveolar reconstruction technique (PDAR). In PDAR, a partial fixed provisional prosthesis (PFPP [conventional or adhesive]) with a specially designed pontic maintains the clot in a mechanically stable position during alveolar regeneration. Moreover, the pontic design, in hourglass shape and located in the subgingival area, also prevents gingival margins from collapsing. Gingival recession was evaluated through the 6-month healing period. Cone beam computed tomography (CBCT) was performed 1 month before and 8 months after PDAR treatment. For the primary outcome, in the panoramic imaging, the central area of bone defect in each tooth was selected for linear measurements. Measurements of the vertical buccal bone gain and the gain in thickness in the alveolar bone crest were obtained 8 months after PDAR. Descriptive statistics and intraclass correlation coefficient analysis were conducted. After treatment, all patients showed bone formation (a mean vertical gain of 7.1±3.7 mm, associated with a horizontal mean gain of 4.5±1.4 mm in the alveolar bone crest). The intraclass correlation coefficient for the measurements performed using CBCT was 0.999. No gingival recession, greater than 1 mm, was observed. Lower-morbidity procedures without the use of biomaterials may be a useful in post-extraction alveolar ridge regeneration and/or preservation. PDAR promoted alveolar bone formation without flaps, grafts and membranes.

Clinical, microbiological, and immunological evaluation of patients in corrective orthodontic treatment.

BACKGROUND: The objective was to analyze clinical, microbiological, and immunological periodontal parameters in patients in corrective orthodontic treatment. MATERIALS AND METHODS: Twenty-eight patients were selected. Plaque index (PI), bleeding on probing (BOP), width of keratinized gingiva, levels of 40 bacterial species, and of 3 cytokines (IL-1ß, MMP-8, and TNF-α) in gingival crevicular fluid (GCF) were evaluated at T0, before orthodontic treatment; T1, 6 months; and T2, 12 months post-treatment. Non-parametric, Friedman, Wilcoxon, ANOVA, and Spearman correlation coefficient tests were used for statistical analyses, with the significance level of 5%. RESULTS: No significant difference was found for the width of keratinized gingiva, but PI presented a significant increase at T1 and T2 (p < 0.05) when compared with T0. The percentage of sites with BOP increased significantly from T0 to T1 (p < 0.05); however, at T2, the values decreased and did not differ anymore from T0 (p > 0.05). In the microbiological analysis, red complex pathogens were in significantly greater proportions in T2 compared with T0 (p < 0.05). There was no statistically significant difference in the cytokine levels between the periods but there was a positive correlation between BOP and IL-1ß (r = 0.49 p = .01) and TNF-α (r = 0.39 and p = .05). CONCLUSION: In conclusion, corrective orthodontic treatment caused clinical periodontal alterations regarding biofilm accumulation and gingival bleeding, with alteration of periodontopathogens.

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.

New strategies and developments for peri-implant disease.

The aim of this illustrated review is to present the new strategies and developments to treatment and diagnosis of periimplant diseases. Periimplant disease is a subject of great concern for modern dentistry. The numbers of implant exhibiting biological complications grows as implant dentistry expands thought-out the world. Diagnosis and treatment of those diseases are still controversial and difficult. We present novel treatment for infection control and biological rationale of additional use of guided bone regeneration, with an illustrative explanation of the treatments presented with two cases.

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.

Comparison of apical periodontitis repair in endodontic treatment with calcium hydroxide-dressing and aPDT.

This study evaluated the effect of antimicrobial photodynamic therapy (aPDT) on the endodontic treatment of apical periodontitis (AP). AP was induced in 48 premolars of 6 dogs. After biomechanical preparation, the teeth were divided into 4 groups: Calcium-Hydroxide (CH)/120d and CH/180d: root canals filled with CH-based dressing for 15 days before obturation; aPDT/120d and aPDT/180d: conditioning with phenothiazine photosensitizer (10 mg/mL) for 1 minute and irradiation with diode laser in the same session as obturation. Root filling was performed with AH Plus sealer. After the experimental periods, animals were euthanized and teeth were submitted for histology. HE staining was performed for descriptive analysis of the periapical region, measurement of apical periodontitis and for inflammatory cells, and blood vessels count. Immunohistochemistry was performed for osteopontin (OPN) and alkaline phosphatase (ALP). Data were analyzed statistically by two-way ANOVA and chi-square test (α = 5%). Teeth in Group CH/120d presented only a slightly enlarged periodontal ligament (PL) with advanced repair. Group aPDT/120d presented the PL moderately enlarged, with moderate inflammatory infiltrate and few collagen fibers. The same pattern was observed at 180 days. AP lesions in CH-treated groups were smaller than those in aPDT-treated groups (p < 0.001) with more blood vessels (p < 0.0001), regardless of the evaluation period, without significant differences in the number of inflammatory cells (p > 0.05). CH-treated groups showed significantly more intense immunostaining for ALP and OPN (p < 0.001) in both periods. Although aPDT stimulated angiogenesis and expression of bone formation markers, the two-session endodontic treatment with CH-based dressing promoted better apical periodontitis repair.

Prosthetically driven alveolar reconstructions: a retrospective study

Abstract This study aims to evaluate the post-extraction alveolar bone reconstruction amongst 12 patients exhibiting loss of buccal bone plate in a tooth of the anterior region of the maxilla using the prosthetically-driven alveolar reconstruction technique (PDAR). In PDAR, a partial fixed provisional prosthesis (PFPP [conventional or adhesive]) with a specially designed pontic maintains the clot in a mechanically stable position during alveolar regeneration. Moreover, the pontic design, in hourglass shape and located in the subgingival area, also prevents gingival margins from collapsing. Gingival recession was evaluated through the 6-month healing period. Cone beam computed tomography (CBCT) was performed 1 month before and 8 months after PDAR treatment. For the primary outcome, in the panoramic imaging, the central area of bone defect in each tooth was selected for linear measurements. Measurements of the vertical buccal bone gain and the gain in thickness in the alveolar bone crest were obtained 8 months after PDAR. Descriptive statistics and intraclass correlation coefficient analysis were conducted. After treatment, all patients showed bone formation (a mean vertical gain of 7.1±3.7 mm, associated with a horizontal mean gain of 4.5±1.4 mm in the alveolar bone crest). The intraclass correlation coefficient for the measurements performed using CBCT was 0.999. No gingival recession, greater than 1 mm, was observed. Lower-morbidity procedures without the use of biomaterials may be a useful in post-extraction alveolar ridge regeneration and/or preservation. PDAR promoted alveolar bone formation without flaps, grafts and membranes.

Resumo Este estudo teve como objetivo avaliar a reconstrução do osso alveolar após extração em 12 pacientes com perda da tábua óssea vestibular em dentes na região anterior da maxila usando a técnica da reconstrução alveolar proteticamente guiada (RAPG). Na RAPG, uma prótese parcial fixa provisória (PPFP [convencional ou adesiva]) com um pôntico com design específico mantém o coágulo numa posição mecanicamente estável. Além disso, o design do pôntico, com formato de ampulheta e localizado na área subgengival, também previne o colapso das margens gengivais. A recessão gengival foi avaliada durante o período de cicatrização de 6 meses. Tomografias computadorizadas cone beam (TCCB) foram feitas 1 mês antes e 8 meses após o tratamento com a RAPG. Para o desfecho primário, nas imagens panorâmicas, a área central do defeito ósseo em cada dente foi selecionada para as medições lineares. As medições do ganho vertical ósseo vestibular e do ganho em espessura na crista óssea alveolar foram realizadas. A análise estística descritiva e a análise do coeficiente de correlação intraclasse forma realizados. Após o tratamento, todos os pacientes apresentaram formação óssea (ganho vertical médio de 7,1±3,7 mm, associado a ganho horizontal médio de 4,5±1,4 mm na crista óssea alveolar). O coeficiente de correlação intraclasse foi de 0,999. Nenhuma retração gengival acima de 1 mm foi observada. Procedimentos com baixa morbidade sem o uso de biomateriais podem ser úteis na regeneração/preservação do rebordo após as extrações. A RAPG promove a formação do osso alveolar sem o uso de retalhos, enxertos e membranas.

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.

New strategies and developments for peri-implant disease

Abstract The aim of this illustrated review is to present the new strategies and developments to treatment and diagnosis of periimplant diseases. Periimplant disease is a subject of great concern for modern dentistry. The numbers of implant exhibiting biological complications grows as implant dentistry expands thought-out the world. Diagnosis and treatment of those diseases are still controversial and difficult. We present novel treatment for infection control and biological rationale of additional use of guided bone regeneration, with an illustrative explanation of the treatments presented with two cases.

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.

Comparison of apical periodontitis repair in endodontic treatment with calcium hydroxide-dressing and aPDT

Abstract This study evaluated the effect of antimicrobial photodynamic therapy (aPDT) on the endodontic treatment of apical periodontitis (AP). AP was induced in 48 premolars of 6 dogs. After biomechanical preparation, the teeth were divided into 4 groups: Calcium-Hydroxide (CH)/120d and CH/180d: root canals filled with CH-based dressing for 15 days before obturation; aPDT/120d and aPDT/180d: conditioning with phenothiazine photosensitizer (10 mg/mL) for 1 minute and irradiation with diode laser in the same session as obturation. Root filling was performed with AH Plus sealer. After the experimental periods, animals were euthanized and teeth were submitted for histology. HE staining was performed for descriptive analysis of the periapical region, measurement of apical periodontitis and for inflammatory cells, and blood vessels count. Immunohistochemistry was performed for osteopontin (OPN) and alkaline phosphatase (ALP). Data were analyzed statistically by two-way ANOVA and chi-square test (α = 5%). Teeth in Group CH/120d presented only a slightly enlarged periodontal ligament (PL) with advanced repair. Group aPDT/120d presented the PL moderately enlarged, with moderate inflammatory infiltrate and few collagen fibers. The same pattern was observed at 180 days. AP lesions in CH-treated groups were smaller than those in aPDT-treated groups (p < 0.001) with more blood vessels (p < 0.0001), regardless of the evaluation period, without significant differences in the number of inflammatory cells (p > 0.05). CH-treated groups showed significantly more intense immunostaining for ALP and OPN (p < 0.001) in both periods. Although aPDT stimulated angiogenesis and expression of bone formation markers, the two-session endodontic treatment with CH-based dressing promoted better apical periodontitis repair.

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. .

Diagnosis and treatment of extraction sockets in preparation for implant placement: report of three cases.

This article addresses diagnostic parameters that should be assessed in the treatment of extraction sockets with dental implant placement by presenting three case reports that emphasize the relevance of the amount of remaining bone walls. Diagnosis was based on the analysis of clinical and radiographic parameters (e.g.: bone defect morphology, remaining bone volume, presence of infections on the receptor site). Case 1 presents a 5-wall defect in the maxillary right central incisor region with severe root resorption, which was treated with immediate implant placement. Cases 2 and 3 present, respectively, two- and three-wall bone defects that did not have indication for immediate implants. These cases were first submitted to a guided bone regeneration (GBR) procedure with bone graft biomaterial and membrane barriers, and the implants were installed in a second surgical procedure. The analysis of the preoperative periodontal condition of the adjacent teeth and bone defect morphology is extremely important because these factors determine the choice between immediate implant or GBR treatment followed by implant installation in a subsequent intervention.

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)

Influence of implant surfaces on osseointegration

The biological fixation between the dental implant surfaces and jaw bones should be considered a prerequisite for the long-term success of implant-supported prostheses. In this context, the implant surface modifications gained an important and decisive place in implant research over the last years. As the most investigated topic in, it aided the development of enhanced dental treatment modalities and the expansion of dental implant use. Nowadays, a large number of implant types with a great variety of surface properties and other features are commercially available and have to be treated with caution. Although surface modifications have been shown to enhance osseointegration at early implantation times, for example, the clinician should look for research evidence before selecting a dental implant for a specific use. This paper reviews the literature on dental implant surfaces by assessing in vitro and in vivo studies to show the current perspective of implant development. The review comprises quantitative and qualitative results on the analysis of bone-implant interface using micro and nano implant surface topographies. Furthermore, the perspective of incorporating biomimetic molecules (e.g.: peptides and bone morphogenetic proteins) to the implant surface and their effects on bone formation and remodeling around implants are discussed.

A fixação biológica entre as superfícies de implante e os ossos maxilares deve ser considerada como um pré-requisito para o sucesso em longo prazo de próteses implanto-suportadas. Neste contexto, as modificações nas superfícies de implante ganharam um lugar importante e decisivo na pesquisa em Implantodontia nos últimos anos. Sendo o tópico mais estudado, colaboraram para o melhoramento de modalidades de tratamento dental, assim como para a expansão de uso dos implantes dentais. Hoje, um grande número de diferentes implantes com uma grande variedade de propriedades de superfícies, entre outras características, está comercialmente disponível e isto deve ser tratado com cuidado. Apesar das modificações nas superfícies terem melhorado a osseointegração em tempos precoces de implantação, por exemplo, o clínico deve procurar evidências científicas antes de selecionar um implante dental para uso específico. Este artigo fará uma revisão da literatura sobre superfícies de implantes osseointegráveis, analisando estudos in vitro e in vivo, a fim de mostrar uma perspectiva atual do desenvolvimento dos implantes. Esta abordagem englobará os resultados obtidos com micro e nano topografias, em termos quantitativos e qualitativos, avaliando a interface osso-implante. Além disso, discutirá também as perspectivas da incorporação de substâncias biomiméticas (como peptídeos e proteínas morfogenéticas) à superfície dos implantes e seus efeitos na modulação da neoformação óssea periimplantar.

Evaluation of in vitro human gingival fibroblast seeding on acellular dermal matrix

The acellular dermal matrix (ADM) was introduced in periodontology as a substitute for the autogenous grafts, which became restricted because of the limited source of donor's tissue. The aim of this study was to investigate, in vitro, the distribution, proliferation and viability of human gingival fibroblasts seeded onto ADM. ADM was seeded with human gingival fibroblasts for up to 21 days. The following parameters were evaluated: cell distribution, proliferation and viability. Results revealed that, at day 7, fibroblasts were adherent and spread on ADM surface, and were unevenly distributed, forming a discontinuous single cell layer; at day 14, a confluent fibroblastic monolayer lining ADM surface was noticed. At day 21, the cell monolayer exhibited a reduction in cell density. At 7 days, about to 90 percent of adherent cells on ADM surface were cycling while at 14 and 21 days this proportion was significantly reduced. A high proportion of viable cell was detected on AMD surface both on 14 and 21 days. The results suggest that fibroblast seeding onto ADM for 14 days can allow good conditions for cell adhesion and spreading on the matrix; however, migration inside the matrix was limited.

A matriz dérmica acelular (MDA) foi introduzida na Periodontia como um substituto para enxertos autógenos, os quais se tornaram restritos devido à quantidade limitada de tecido doador. O objetivo deste estudo foi verificar, in vitro, a distribuição, proliferação e viabilidade de fibroblastos gengivais humanos cultivados em MDA. Fibroblastos gengivais foram cultivados sobre MDA por até 21 dias. Os seguintes parâmetros foram avaliados: distribuição, proliferação e viabilidade celular. Os resultados revelaram que, aos 7 dias, os fibroblastos estavam aderidos e espraiados na superfície da MDA, e estavam distribuídos de forma desigual, formando uma camada celular descontínua; aos 14 dias, uma monocamada confluente de fibroblastos revestindo a superfície da MDA foi observada. Aos 21 dias, a monocamada celular exibiu uma redução na densidade celular. Aos 7 dias, cerca de 90 por cento das células aderidas na superfície da MDA estavam no ciclo celular, enquanto que aos 14 e 21 dias esse número reduziu significativamente. Uma maior proporção de células viáveis foi detectada na superfície da MDA tanto aos 14 quanto aos 21 dias. Os resultados sugerem que fibroblastos cultivados sobre a MDA por 14 dias permitem boas condições de adesão e espraiamento das células sobre a matriz, porém, a migração de células para o interior da matriz foi limitada.

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.