Employing Indirect Adenosine 2A Receptors (A2AR) to Enhance Osseointegration of Titanium Devices: A Pre-Clinical Study.

The present study aimed to evaluate the effect of dipyridamole, an indirect adenosine 2A receptors (A2AR), on the osseointegration of titanium implants in a large, translational pre-clinical model. Sixty tapered, acid-etched titanium implants, treated with four different coatings ((i) Type I Bovine Collagen (control), (ii) 10 µM dipyridamole (DIPY), (iii) 100 µM DIPY, and (iv) 1000 µM DIPY), were inserted in the vertebral bodies of 15 female sheep (weight ~65 kg). Qualitative and quantitative analysis were performed after 3, 6, and 12 weeks in vivo to assess histological features, and percentages of bone-to-implant contact (%BIC) and bone area fraction occupancy (%BAFO). Data was analyzed using a general linear mixed model analysis with time in vivo and coating as fixed factors. Histomorphometric analysis after 3 weeks in vivo revealed higher BIC for DIPY coated implant groups (10 µM (30.42% ± 10.62), 100 µM (36.41% ± 10.62), and 1000 µM (32.46% ± 10.62)) in comparison to the control group (17.99% ± 5.82). Further, significantly higher BAFO was observed for implants augmented with 1000 µM of DIPY (43.84% ± 9.97) compared to the control group (31.89% ± 5.46). At 6 and 12 weeks, no significant differences were observed among groups. Histological analysis evidenced similar osseointegration features and an intramembranous-type healing pattern for all groups. Qualitative observation corroborated the increased presence of woven bone formation in intimate contact with the surface of the implant and within the threads at 3 weeks with increased concentrations of DIPY. Coating the implant surface with dipyridamole yielded a favorable effect with regard to BIC and BAFO at 3 weeks in vivo. These findings suggest a positive effect of DIPY on the early stages of osseointegration.

Effects of local single dose administration of parathormone on the early stages of osseointegration: A pre-clinical study.

The present study aimed to evaluate the effect of parathormone (PTH) administered directly to the implant's surface prior to insertion, using a large translational animal model. Sixty titanium implants were divided into four groups: (i) Collagen, control group, where implants were coated with Type-I Bovine-collagen, and three experimental groups, where implants received varying doses of PTH: (ii) 12.5, (iii) 25, and (iv) 50 µg, prior to placement. Fifteen female sheep (~2 years old, weighing ~65 kg) received four implants in an interpolated fashion in C3, C4 or C5 vertebral bodies. After 3-, 6- and 12-weeks, samples were harvested, histologically processed, qualitatively and quantitatively assessed for bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO). BIC yielded lower values at 6-weeks for 50 µg relative to the control group, with no significant differences, when compared to the 12.5- and 25-µg. No significant differences were detected at 6-weeks between collagen, 12.5- and 25-µg groups. At 3- and 12-weeks, no differences were detected for BIC among PTH groups. With respect to BAFO, no significant differences were observed between the control and experimental groups independent of PTH concentration and time in vivo. Qualitative observations at 3-weeks indicated the presence of a more mature bone near the implant's surface with the application of PTH, however, no significant differences in new bone formation or healing patterns were observed at 6- and 12-weeks. Single local application of different concentrations of PTH on titanium implant's surface did not influence the osseointegration at any time-point evaluation in low-density bone.

Oral and masticatory rehabilitation using osseointegrated dental implants after resective treatment of multicystic ameloblastoma in the lower jaw with a fibula graft.

Ameloblastoma is an aggressive odontogenic tumor which typically occurs between third and fourth decade of life that often needs resective approach. Immediate reconstruction may show better results. The treatment of multicystic ameloblastoma in the mandible being a rare case that occurred in the late second decade of life, which was surgically removed along with the affected teeth with safety margins, and the region was immediately reconstructed using a vascularized graft, removed from the fibula. Its integration, in combination with osseointegrated dental implants and fixed implant-supported prostheses, restored chewing function and esthetics. After 6 years from fibular graft and 24 months of dental implants, an excellent outcome was observed, with oral health and normal functions properly restored, and the immediate reconstruction of the mandible in resective cases, associated with oral rehabilitation with dental implants, may be considered a suitable treatment option.

Saúde bucal e periodontal podem ser afetadas após cirurgia bariátrica e deficiências nutricionais? / an oral and periodontal health may be affected after bariatric surgery and nutritional deficiencies?

Objetivo: tentar entender como as deficiências nutricionais no paciente pós-operatório à cirurgia bariátrica impactam a saúde oral e periodontal. Material e métodos: uma pesquisa na base de dados PubMed com os termos "by-pass gástrico e doenças periodontais", "cirurgia bariátrica e deficiências nutricionais", e "saúde bucal e obesidade" tentando esclarecer a relação com doença periodontal e as deficiências nutricionais. Resultados: foi realizada uma revisão de artigos sobre o fato da cirurgia bariátrica ser um procedimento cirúrgico indicado para o tratamento da obesidade mórbida e promover alteração da anatomia gastrintestinal, levando à perda de peso, diminuindo a absorção de açúcares, gorduras e outros nutrientes importantes, como vitaminas A, C, D, B12, cálcio e ferro, responsáveis pela regulação de muitas funções críticas no organismo e participantes efetivos na produção de colágeno e matriz óssea. Conclusão: a cavidade oral sofre complicações em vista dessa nova situação, e os dentistas precisam entender como essas deficiências podem afetar na doença periodontal, a fim de desenvolver estratégias de prevenção e tratamento para este novo grupo de população.

Objective: the aim of this article is try to understand how the nutritional deficiencies in the post-operative patient submitted to bariatric surgery impact on oral and periodontal health. Material and methods: a survey in PubMed database with these terms "gastric by-pass and periodontal diseases", "bariatric surgery and nutritional deficiencies" and "oral health and obesity" was done trying to clarify the relationship with periodontal disease. Results: bariatric surgery is a surgical procedure indicated for the treatment of morbid obesity and promotes an alteration of gastrointestinal anatomy leading to a marked weight loss by decreasing the absorption of sugars and fats, but other important nutrients such as decreased absorption of vitamins A, C, D, B12, calcium and iron, which are also responsible for the regulation of many critical functions in organism, and effectively participate in the production of collagen and bone matrix and an overview of papers about this topic was conducted. Conclusion: the oral cavity suffers complications from this new situation and dentists need to understand how these deficiencies may impact on periodontal disease in order to develop treatment and prevention strategies for this new population group.

Tissue reaction of deproteinized bovine bone matrix grafting in ectopic site: histological study on sheep.

The aim of this paper was to evaluate through histological analysis of the tissue reaction of deproteinized bovine bone matrix (DBBM) when inserted into the site of intramuscular ectopic sheep. In this study, 16 sheep received 3 groups and these were divided into 2 experimental times: Group 1-sham group, Group 2-particulate autogenous bone and Group 3-DBBM granules. All animals underwent surgical procedures for insertion of materials in an ectopic site (muscles of the lower back and after 3 and 6 months postoperatively, the samples were evaluated by histological analysis. The results indicated that the Sham group showed dense collagen fibers and thin, characterizing fibrosis at 3 and 6 months. In the autograft group there was a significant amount of collagen deposition and decreased inflammation at 6 months postoperatively. Group of DBBM, it was noted the presence of dense connective tissue and surrounding remaining particles was observed the formation of with osteoid characteristic tissue. The DBBM demonstrated biocompatibility, osteoconductivity and small osteogenesis capacity on ectopic site.

Evaluation of Discoloration Removal by Polishing Resin Composites Submitted to Staining in Different Drink Solutions.

The aim of this study was to evaluate the discoloration effects of water, cola-based soft drink, coffee, and wine on resin composites used in restorative dentistry and the possibility of removing the stain with chair side manual polishing. The A2 shade of three materials was tested. Disc specimens were prepared. A spectrophotometer was used to measure the baseline CIE-Lab color parameters of each material (n=10) 24 hours after sample preparation. Samples were then immersed in a cola-based soft drink, coffee, or wine for 1 hour every day, for 30 days. For the remaining hours, the specimens were stored in distilled water. In the control group, the specimens were immersed in water for the whole period. The color differences (ΔE) were calculated after 7 and 30 days of storage, and after polishing with coarse Sof-Lex discs, and analyzed by two-way ANOVA with repeated measures and Tukey's HSD test (α=0.05). Luna presented higher ΔE values (3.41) (a) followed by Durafill (2.82) (b) and Herculite (2.24) (c) . For the drink solutions, ΔE values were higher for wine (4.40) (a) followed by coffee (2.59) (b) and for cola-based soft drink (2.23) (c) and water (2.13) (c) which were statistically similar. For time, ΔE values were higher for 30 days (3.97) (a) and then for 7 days (2.48) (b) and after polishing (2.04) (c) . The results indicate that color stability is material dependent. The types of drinks that patients consume also influence the color stability of restorative materials.

Leukocyte-platelet-rich plasma (L-PRP) induces an abnormal histophenotype in craniofacial bone repair associated with changes in the immunopositivity of the hematopoietic clusters of differentiation, osteoproteins, and TGF-ß1.

BACKGROUND: Leukocyte-platelet-rich plasma (L-PRP) is considered an important source of growth factors, especially Transforming growth factor ß 1 (TGF-ß1), which modulates the proliferation and regulation of mesenchymal cells, and also exerts an influence on the hematopoiesis, osteogenesis, and adipogenesis in bone microenvironment. Thus, the aim of this study was to evaluate the effect of L-PRP on the calvarial bone repair and compare its results on the presence of TGF-ß1, CD34, CD45, bone morphogenetic protein 2 (BMP2), BMPR1B, and Runx2 proteins detected by immunohistochemistry. MATERIAL AND METHODS: Four bone defects were created on the calvaria of 23 rabbits. The defects were treated with autograft, L-PRP alone, and L-PRP mixed with autograft. The animals were euthanized at 2, 4, and 6 weeks post-surgery. RESULTS: Unlike autograft and sham groups, the defects treated with L-PRP demonstrated significant positivity to TGF-ß1, while the BMP2 was scarce. These results coincided with the lower bone matrix deposited and larger medullary area, which were composed of fibrosis, when treated with only L-PRP, or intense adiposity on defects filled with L-PRP mixed with autograft. The fibrosis that occurred was associated with a minor percentage of osteoproteins, intense presence of CD34(+) CD45(-) cells, and significant expression of TGF-ß1 in all time periods analyzed. The adiposity occurred from the major presence of osteoprogenitor BMPR1B (+) Runx2(+) cells simultaneously to BMP2(-) TGF-ß1(+) and CD34(+) CD45(+/-) expressions predominantly on the earlier period. CONCLUSION: From this study, it can be concluded that the L-PRP used alone or mixed to autograft hindered the osteoneogenesis due to suppression of immunoexpression of BMP2, while the immunopositivity of TGF-ß1 was intense. When used alone, the L-PRP induced a fibrotic condition associated with TGF-ß1 presence and lack of osteoproteins, but when L-PRP was mixed to autograft, it induced the presence of the osteolineage cells (BMPR1B (+) Runx2(+) ), but also inhibited the terminal osteoblastic maturation associated with the lack of BMP2 and the presence of TGF-ß1(+) , a fact that contributed to cellular transdifferentiation into fat cells.

Deslizamento de retalho palatino: visão estética / The palatal sliding flap: an aesthetic view

A relação implante/estética está se tornando cada vez mais desafiadora, pois para uma prótese adequada, devemos conhecer e imitar forma e contorno do dente adjacente, papila interdental, zênite gengival, dentre outros. Pensando nesta combinação, os autores propuseram, neste trabalho, uma técnica modificada visando oferecer um prognóstico estético favorável. As técnicas utilizadas foram a de preenchimento alveolar com osso liofilizado bovino pós-exodontia e deslizamento de retalho palatino modificado no fechamento da ferida alveolar. O objetivo desta associação de técnicas é a manutenção do rebordo para diminuição da perda de crista óssea e/ou parede vestibular, manutenção do arcabouço alveolar quando existem defeitos estabelecidos, fechamento por primeira intenção da ferida cirúrgica e ganho de tecido gengival para a reorganização de papila interdental e zênite gengival evitando, assim, a necessidade de um segundo momento cirúrgico na manipulação de tecido mole para ganho estético. Os resultados são provenientes da prática clínica, porém, de extrema satisfação.

The relationship between aesthetics and implants is becoming more and more important. It is imperative that we know about the restored tooth’s planned shape and contour to have an appropriate prosthesis with adequate interdental papillae and gingival margins. In this paper, the authors propose a modified extraction closure procedure attempting to offer a favorable aesthetic prognosis for the final implant. We used two different alveolar preservation techniques with freeze-dried bone after tooth extraction and a modified palatal rotation flap for soft tissue coverage. The aim was to keep buccal and alveolar crest bone loss to a minimum and to have closure and healing by primary intention. The procedure was designed to enhance soft tissue reorganization of the interdental papillae and marginal gingival tissue. Using these combined techniques, there is no need to gain soft tissue in a second surgical procedure. The results are variable, but extreme satisfactory.