Comparative Evaluation of Implants with Different Surface Treatments Placed in Human Edentulous Mandibles: A 1-Year Prospective Study.

The aims of this study were to analyze prospectively and comparatively the peri-implant bone crest levels, bone density, stability and success rate of implants with different surface treatments in human edentulous mandibles. Twenty edentulous patients were selected. Four different implants were placed between the mental foramen. Four groups were evaluated: (1) laser-modified surface (LASER), (2) surface modified by laser with deposition of apatites (LASER + HA), (3) surface modified by double acid etching (ACID, Implacil De Bortoli) and (4) surface modified by sandblasting and acid etching (SLActive®, Straumann). Clinical, radiographic, resonance frequency and tomographic analyses were used. After 4 months, mandibular fixed implant prostheses were installed. Clinical and radiographic analyses were performed at times T0 (immediately after implant placement), T1 (15 days), T2 (30 days), T3 (60 days), T4 (90 days), T5 (120 days), T6 (180 days) and T7 (360 days), post-implant placement. The resonance frequency analysis (RFA) was measured at T0, T4, T6 and T7. The tomographic analysis was performed at T0, T4 and T7. In the radiographic bone density analysis, a statistical difference was found between the SLActive® and LASER + HA groups at T4 (p < 0.05). Statistical differences were observed in RFA at T4 (90 days), between the SLActive® and LASER groups (p < 0.05) and between the SLActive® and LASER + HA groups (p < 0.05). At T6 and T7, statistical differences were found between the SLActive® group and all other implant surfaces (p < 0.01). The experimental surfaces analyzed showed encouraging positive outcomes compared to those of the SLActive® surface. Long-term follow-up should be performed to confirm these results.

Experimental models of orthodontic tooth movement and their effects on periodontal tissues remodelling.

OBJECTIVES: The present study aimed to compare two different models of orthodontic tooth movement (OTM) in rats by evaluating tooth movement efficiency and periodontal tissues remodelling. DESIGN: Fifteen animals were randomly distributed into 3 groups: control group (untreated); ligature appliance (LA) as experimental OTM using a closed coil spring fixed around maxillary first molar by steel ligature; occlusal appliance (OA) as experimental OTM using a closed coil spring attached on the occlusal surface of the maxillary first molar. After 15 days, all animals were euthanized, and the maxilla of each animal was collected for qPCR, micro-computed tomography, and histological analyses. RESULTS: Interleukin-1 beta, interleukin-6, and tumor necrosis factor-alpha gene expressions were significantly upregulated in the animals of the LA group as compared to the other groups. No significant difference was observed in tooth displacement between both methods. The LA group presented higher linear bone loss and lower values of bone volume fraction, bone mineral density, trabecular number and increased values of trabecular separation compared to the other groups. The birefringent collagen content in the tension side of the periodontal ligament contained significantly lower collagen content in the LA group than in the control group. Furthermore, on the pressure side, the collagen content was significantly lower in the LA and OA groups than in the control group. CONCLUSIONS: The OA group presented little or no deleterious effect on periodontal tissues compared to the LA group, suggesting its use may be more reliable for OTM induction in rats for 15 days.

CXCL5, CXCL8, and CXCL10 regulation by bacteria and mechanical forces in periodontium.

OBJECTIVE: The aim of the present study was to evaluate the expressions of CXCL5, CXCL8, and CXCL10 in periodontal cells and tissues in response to microbial signals and/or biomechanical forces. METHODS: Human gingival biopsies from inflamed and healthy sites were used to examine the chemokine expressions and protein levels by real-time PCR and immunohistochemistry. The chemokines were also investigated in gingival biopsies from rats submitted to experimental periodontitis and/or tooth movement. Furthermore, chemokine levels were determined in human periodontal fibroblasts stimulated by the periodontopathogen Fusobacterium nucleatum and/or constant tensile forces (CTS) by real-time PCR and ELISA. Additionally, gene expressions were evaluated in periodontal fibroblasts exposed to F. nucleatum and/or CTS in the presence and absence of a MAPK inhibitor by real-time PCR. RESULTS: Increased CXCL5, CXCL8, and CXCL10 levels were observed in human and rat gingiva from sites of inflammation as compared with periodontal health. The rat experimental periodontitis caused a significant (p<0.05) increase in alveolar bone resorption, which was further enhanced when combined with tooth movement. In vitro, F. nucleatum caused a significant upregulation of CXCL5, CXCL8, and CXCL10 at 1 day. Once the cells were exposed simultaneously to F. nucleatum and CTS, the chemokines regulation was significantly enhanced. The transcriptional findings were also observed at protein level. Pre-incubation with the MEK1/2 inhibitor significantly (p<0.05) inhibited the stimulatory actions of F. nucleatum either alone or in combination with CTS on the expression levels of CXCL5, CXCL8, and CXCL10 at 1d. CONCLUSIONS: Our data provide original evidence that biomechanical strain further increases the stimulatory actions of periodontal bacteria on the expressions of these chemokines. Therefore, biomechanical loading in combination with periodontal infection may lead to stronger recruitment of immunoinflammatory cells to the periodontium, which might result in an aggravation of periodontal inflammation and destruction.

Resistin Is Increased in Periodontal Cells and Tissues: In Vitro and In Vivo Studies.

Resistin, a proinflammatory adipokine, is elevated in many inflammatory diseases. However, little is known about its performance in periodontitis. The present study is aimed at evaluating resistin expression and synthesis in periodontal cells and tissues under inflammatory/microbial stress in addition to its effects on the periodontium. In vivo, 24 male rats were randomly divided into two groups: control and ligature-induced periodontal disease. After 6 and 12 days, animals were sacrificed to analyze gene expression of adipokines, bone loss, inflammation, and resistin synthesis. In vitro, human periodontal ligament (PDL) fibroblasts were used to evaluate the expression of resistin after inflammatory stimuli. In addition, PDL fibroblasts were exposed to resistin to evaluate its role on soft and hard tissue metabolism markers. The periodontitis group demonstrated significant bone loss, an increase in the number of inflammatory cells and vascular structures, an increase in resistin expression and synthesis, and a decrease in the expression of adiponectin, leptin, and its functional receptor. PDL fibroblasts showed a significant increase in resistin expression and synthesis in response to the inflammatory stimulus by IL-1ß. Resistin induced an increase in cytokine expression and a decrease in the regulation of some hard tissue and matrix formation genes in PDL fibroblasts. These data indicate that resistin is produced by periodontal cells and tissues, and this effect is enhanced by inflammatory stimuli. Moreover, resistin seems to interfere with soft and hard tissue metabolism during periodontitis by reducing markers related to matrix formation and bone tissue.

ST2 regulates bone loss in a site-dependent and estrogen-dependent manner.

Interleukin-33 (IL-33) and its receptor, ST2, are implicated in bone remodeling. The lack of estrogen after menopause results in an accelerated bone loss. Here we investigated the role of ST2 in the bone loss induced by estrogen deficiency. ST2-deficient mice (ST2-/- ) and their littermates (wildtype [WT]) were ovariectomized (OVX), while ovary-intact mice were used as controls. Bone sites were analyzed by microcomputed tomography, histomorphometry, and quantitative real-time polymerase chain reaction (qPCR). Deletion of IL-33 or ST2 resulted in a similar bone loss in the femur and maxilla. Ovariectomy in WT mice caused bone loss in the same areas. The lack of ST2 in OVX mice did not alter bone remodeling in the femur but prevented bone loss in the maxilla. Consistently, ovariectomy increased the IL-33 messenger RNA (mRNA) levels in the maxilla but not in the femur. Under mechanical stimulation, ovariectomy and ST2 deletion independently increased bone remodeling induced by orthodontic tooth movement, which was also associated with a greater number of osteoclasts and a reduced number of osteoblasts in the maxillary bone. ST2-/- OVX mice, however, displayed twice as many osteoblasts as that of WT OVX mice. Ovariectomy and ST2 deletion differently altered the cytokine mRNA levels in the maxilla. Remarkably, interleukin-10 expression was decreased in both WT OVX and ST2-/- mice, and this reduction was completely restored in ST2-/- OVX mice. The results demonstrate that estrogen and IL33/ST2 independently protect against bone loss. However, the ovariectomy-induced bone loss is IL-33/ST2-dependent in the maxilla but not in the femur, indicating a bimodal and site-specific role of ST2 in bone remodeling.

Evaluation of Short and Regular Implants after Prosthesis Placement in the Mandible: A Nonrandomized Controlled Clinical Trial.

AIM: The aim of this nonrandomized controlled preliminary clinical trial was to compare treatment using short and conventional implants in the posterior region of the mandible after prosthesis installation by means of clinical, resonance frequency, and radiographic analyses. MATERIALS AND METHODS: A total of 10 patients with 40 dental implants already installed were included in this study. Four implants were installed for each subject, in which the length of the implants (short and conventional) was distributed according to the reminiscent alveolar bone in the left and right side of the mandible. All implants received splinted prosthesis after the osseointegration period. Analyses were performed immediately after prosthesis installation (T1), and 3 (T2) and 6 months (T3) after prosthesis placement. RESULTS: The 6-month survival and success rates were 100% for the short and conventional implants. Probing depths (PDs) after 6 months did not show statistical differences between short and conventional implants. All groups showed mean implant stability quotient (ISQ) values above 60 in all periods evaluated, demonstrating great implant stability, and no differences were found between groups at T3. Radiographic measurements showed an increased bone loss for conventional implants compared with short implants in all the three periods evaluated. CONCLUSION: Our findings suggest that treatment of resorbed posterior regions in the mandible with shorter dental implants is as reliable as treatment with conventional implants after 6 months of splinted prosthesis installation. CLINICAL SIGNIFICANCE: Short implants might be considered a predictable treatment alternative to bone augmentation or extensive surgical techniques in regions of restricted vertical bone height in the posterior region of the mandible.

Periodontal pathogens directly promote autoimmune experimental arthritis by inducing a TLR2- and IL-1-driven Th17 response.

Increasing epidemiologic evidence supports a link between periodontitis and rheumatoid arthritis. The actual involvement of periodontitis in the pathogenesis of rheumatoid arthritis and the underlying mechanisms remain, however, poorly understood. We investigated the influence of concomitant periodontitis on clinical and histopathologic characteristics of T cell-mediated experimental arthritis and evaluated modulation of type II collagen (CII)-reactive Th cell phenotype as a potential mechanism. Repeated oral inoculations of periodontal pathogens Porphyromonas gingivalis and Prevotella nigrescens induced periodontitis in mice, as evidenced by alveolar bone resorption. Interestingly, concurrent periodontitis induced by both bacteria significantly aggravated the severity of collagen-induced arthritis. Exacerbation of arthritis was characterized by increased arthritic bone erosion, whereas cartilage damage remained unaffected. Both P. gingivalis and P. nigrescens skewed the CII-specific T cell response in lymph nodes draining arthritic joints toward the Th17 phenotype without affecting Th1. Importantly, the levels of IL-17 induced by periodontal pathogens in CII-specific T cells directly correlated with the intensity of arthritic bone erosion, suggesting relevance in pathology. Furthermore, IL-17 production was significantly correlated with periodontal disease-induced IL-6 in lymph node cell cultures. The effects of the two bacteria diverged in that P. nigrescens, in contrast to P. gingivalis, suppressed the joint-protective type 2 cytokines, including IL-4. Further in vitro studies showed that the Th17 induction strongly depended on TLR2 expression on APCs and was highly promoted by IL-1. Our data provide evidence of the involvement of periodontitis in the pathogenesis of T cell-driven arthritis through induction of Ag-specific Th17 response.

Parotidite aguda em jovem adulto sistemicamente saudável. Relato de caso / Acute parotitis in a systemically healthy young adult. A case report

Objetivo: Este estudo relata um caso incomum de parotidite aguda em um paciente adulto jovem, saudável e com boa higiene oral. Relato de Caso: O paciente procurou o Departamento de Estomatologia, na Universidade Estadual de Ponta Grossa devido a um inchaço na região da glândula parótida direita. O paciente foi submetido a exames clínicos e radiológicos e foi prescrito tratamentos com drogas anti-inflamatórias e antibióticos. No quinto dia os sinais e sintomas haviam desaparecido. Conclusão: O desenvolvimento de parotidite aguda em adultos jovens saudáveis com uma boa higiene oral é possível, mas isso torna o diagnóstico mais difícil. Anti-inflamatórios, antibióticos e fisioterapia associada com calor pode contribuir para a recuperação dos sinais e sintomas após 5 dias de tratamento.

Aim: This study reports an unusual case of acute parotitis in a healthy young adult with good oral hygiene. Case Report: The patient sought the Department of Stomatology, at Ponta Grossa State University due to a swollen on the right parotid gland region. The patient underwent clinical and radiological treatments and was prescribed anti-inflammatory drugs and antibiotics. On the fifth day the signs and symptoms had disappeared. Conclusion: The development of acute parotitis in healthy young adults with good oral hygiene is possible, but this makes the diagnosis more difficult. Anti-inflammatory, antibiotic and heat physiotherapy can contribute to the recovery of the signs and symptoms after 5 days of treatment.

Tratamento de recessões gengivais múltiplas: uma abordagem cirúrgica mais conservadora / Periodontal plastic surgery for treatment multiple gingival recession: a less invasive approach

A terapêutica periodontal tem passado por mudanças significativas nas últimas décadas. Enquanto no passado seu objetivo era apenas restabelecer a saúde gengival sem haver preocupação com as possíveis sequelas do tratamento da doença, atualmente, os procedimentos são realizados de maneira menos invasiva com intuito de manter os padrões estéticos periodontais ou até de recuperá-los. A recessão gengival é uma alteração frequentemente encontrada em pacientes, podendo ser uma queixa importante por provocar diversas complicações. Para seu tratamento, diversas técnicas cirúrgicas são relatadas na literatura. As que possuem maior previsibilidade são aquelas que associam um enxerto de conjuntivo subepitelial a um retalho coronalmente reposicionado. A técnica original consiste na realização de duas incisões relaxantes para ampla liberação do retalho e para sua estabilização em uma posição mais coronal. Embora este procedimento seja extremamente difundido na literatura, a busca por cirurgias menos invasivas sem a utilização de incisões relaxantes pode ser considerada como um dos atuais objetivos da cirurgia plástica periodontal, já que apresentam uma série de vantagens. O objetivo deste artigo foi demonstrar um caso clínico onde recessões múltiplas, profundas e adjacentes, que causavam como queixa principal a estética, foram sanadas por meio de uma abordagem menos invasiva, utilizando técnica cirúrgica em envelope, associada ao enxerto de tecido conjuntivo subepitelial.A terapêutica periodontal tem passado por mudanças significativas nas últimas décadas. Enquanto no passado seu objetivo era apenas restabelecer a saúde gengival sem haver preocupação com as possíveis sequelas do tratamento da doença, atualmente, os procedimentos são realizados de maneira menos invasiva com intuito de manter os padrões estéticos periodontais ou até de recuperá-los. A recessão gengival é uma alteração frequentemente encontrada em pacientes, podendo ser uma queixa importante por provocar...

Uma opção terapêutica para o aumento da faixa de gengiva inserida: o enxerto de tecido conjuntivo livre / A therapeutic option to increase attached gingiva: the free connective tissue graft

Uma ampla variedade de procedimentos cirúrgicos periodontais tem sido descrita na literatura para correção de problemas mucogengivais e para cobertura radicular. O enxerto gengival livre epitelizado é um procedimento bem estabelecido para aumentar a faixa de gengiva ceratinizada, com resultados favoráveis em longo prazo. Entretanto, este procedimento não é comumente utilizado em regiões estéticas, pois o tecido enxertado apresenta diferença de cor e contraste com os tecidos adjacentes. Neste sentido, o enxerto de tecido conjuntivo livre surge como uma opção viável para aumento de gengiva inserida em regiões onde a demanda estética é necessária. Enquanto que a remoção do enxerto gengival livre da região do palato duro cria uma área cruenta e dolorida que demora a reparar, a do enxerto de tecido conjuntivo produz apenas uma área de incisão facilmente suturada, sendo mais confortável ao paciente. Sendo assim, o objetivo do presente relato foi apresentar um caso clínico tratado com a técnica de enxerto gengival livre de tecido conjuntivo para aumento da quantidade de gengiva inserida em um dente com recessão gengival. No caso apresentado, a técnica de enxerto conjuntivo livre apresentou resultados estéticos satisfatórios, com melhor coloração e contraste com os tecidos adjacentes.