Performance of Polydioxanone-Based Membrane in Association with 3D-Printed Bioceramic Scaffolds in Bone Regeneration.

This study evaluated the bioactivity of 3D-printed ß-tricalcium phosphate (ß-TCP) scaffolds or hydroxyapatite (HA) scaffolds associated with polydioxanone (PDO) membrane (Plenum® Guide) for guided bone regeneration in rats. Fifty-four rats were divided into three groups (n = 18 animals): autogenous bone + PDO membrane (Auto/PG); 3D-printed ß-TCP + PDO membrane (TCP/PG); and 3D-printed HA + PDO membrane (HA/PG). A surgical defect in the parietal bone was made and filled with the respective scaffolds and PDO membrane. The animals were euthanized 7, 30, and 60 days after the surgical procedure for micro-CT, histomorphometric, and immunolabeling analyses. Micro-CT showed an increase in trabecular thickness and a decrease in trabecular separation, even with similar bone volume percentages between TCP/PG and HA/PG vs. Auto/PG. Histometric analysis showed increased bone formation at 30 days in the groups compared to 7 days postoperatively. Immunolabeling analysis showed an increase in proteins related to bone formation at 30 days, and both groups showed a similar immunolabeling pattern. This study concludes that 3D-printed scaffolds associated with PDO membrane (Plenum® Guide) present similar results to autogenous bone for bone regeneration.

Polydioxanone-Based Membranes for Bone Regeneration.

Resorbable synthetic and natural polymer-based membranes have been extensively studied for guided tissue regeneration. Alloplastic biomaterials are often used for tissue regeneration due to their lower immunoreactivity when compared with allogeneic and xenogeneic materials. Plenum® Guide is a synthetic membrane material based on polydioxanone (PDO), whose surface morphology closely mimics the extracellular matrix. In this study, Plenum® Guide was compared with collagen membranes as a barrier material for bone-tissue regeneration in terms of acute and subchronic systemic toxicity. Moreover, characterizations such as morphology, thermal analysis (Tm = 107.35 °C and crystallinity degree = 52.86 ± 2.97 %, final product), swelling (thickness: 0.25 mm ≅ 436% and 0.5 mm ≅ 425% within 24 h), and mechanical tests (E = 30.1 ± 6.25 MPa; σ = 3.92 ± 0.28 MPa; ε = 287.96 ± 34.68%, final product) were performed. The in vivo results revealed that the PDO membranes induced a slightly higher quantity of newly formed bone tissue than the control group (score: treated group = 15, control group = 13) without detectable systemic toxicity (clinical signs and evaluation of the membranes after necropsy did not result in differences between groups, i.e., non-reaction -> tissue-reaction index = 1.3), showing that these synthetic membranes have the essential characteristics for an effective tissue regeneration. Human adipose-derived stem cells (hASCs) were seeded on PDO membranes; results demonstrated efficient cell migration, adhesion, spread, and proliferation, such that there was a slightly better hASC osteogenic differentiation on PDO than on collagen membranes. Hence, Plenum® Guide membranes are a safe and efficient alternative for resorbable membranes for tissue regeneration.

Metabolic activity of hydro-carbon-oxo-borate on a multispecies subgingival periodontal biofilm: a short communication.

OBJECTIVE: This study evaluated the metabolic activity of hydro-carbon-oxo-borate complex (HCOBc) on a multispecies subgingival biofilm as well as its effects on cytotoxicity. MATERIALS AND METHODS: The subgingival biofilm with 32 species related to periodontitis was formed in the Calgary Biofilm Device (CBD) for 7 days. Two different therapeutic schemes were adopted: (1) treatment with HCOBc, 0.12% chlorhexidine (CHX), and negative control group (without treatment) from day 3 until day 6, two times a day for 1 min each time, totaling 8 treatments and (2) a 24-h treatment on a biofilm grown for 6 days. After 7 days of formation, biofilm metabolic activity was determined by colorimetry assay, and bacterial counts and proportions of complexes were determined by DNA-DNA hybridization. Both substances' cytotoxicity was evaluated by cell viability (XTT assay) and clonogenic survival assay on ovary epithelial CHO-K1 cells and an osteoblast precursor from calvaria MC3T3-E1 cells. RESULTS: The first treatment scheme resulted in a significant reduction in biofilm's metabolic activity by means of 77% by HCOBc and CHX treatments versus negative control. The total count of 11 and 25 species were decreased by treatment with hydro-carbon-oxo-borate complex and CHX, respectively, compared with the group without treatment (p < 0.05), highlighting a reduction in the levels of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Fusobacterium periodontium. CHX significantly reduced the count of 10 microorganisms compared to the group treated with HCOBc (p < 0.05). HCOBc and CHX significantly decreased the pathogenic red-complex proportion compared with control-treated biofilm, and HCOBc had even a more significant effect on the red complex than CHX had (p ≤ 0.05). For the second treatment scheme, HCOBc complex and CHX significantly decreased 61 and 72% of control biofilms' metabolic activity and the counts of 27 and 26 species, respectively. HCOBc complex did not significantly affect the proportions of formed biofilms, while CHX significantly reduced red, orange, and yellow complexes. Both substances exhibited similar cytotoxicity results. CONCLUSIONS: This short communication suggested that the HCOBc complex reduced a smaller number of bacterial species when compared to chlorhexidine during subgingival biofilm formation, but it was better than chlorhexidine in reducing red-complex bacterial proportions. Although HCOBc reduced the mature 6-day-old subgingival multispecies biofilms, it did not modify bacterial complexes' ratios as chlorhexidine did on the biofilms mentioned above. Future in vivo studies are needed to validate these results. CLINICAL RELEVANCE: HCOBc complex could be used to reduce red-complex periodontal bacterial proportions.

Bioresorbable Polymers: Advanced Materials and 4D Printing for Tissue Engineering.

Three-dimensional (3D) printing is a valuable tool in the production of complexes structures with specific shapes for tissue engineering. Differently from native tissues, the printed structures are static and do not transform their shape in response to different environment changes. Stimuli-responsive biocompatible materials have emerged in the biomedical field due to the ability of responding to other stimuli (physical, chemical, and/or biological), resulting in microstructures modifications. Four-dimensional (4D) printing arises as a new technology that implements dynamic improvements in printed structures using smart materials (stimuli-responsive materials) and/or cells. These dynamic scaffolds enable engineered tissues to undergo morphological changes in a pre-planned way. Stimuli-responsive polymeric hydrogels are the most promising material for 4D bio-fabrication because they produce a biocompatible and bioresorbable 3D shape environment similar to the extracellular matrix and allow deposition of cells on the scaffold surface as well as in the inside. Subsequently, this review presents different bioresorbable advanced polymers and discusses its use in 4D printing for tissue engineering applications.

Biopolymer-based membranes associated with osteogenic growth peptide for guided bone regeneration.

Barrier membranes for guided bone regeneration (GBR) mainly promote mechanical maintenance of bone defect space and induce osteopromotion. Additionally, biopolymer-based membranes may provide greater bioactivity and biocompatibility due to their similarity to extracellular matrix (ECM). In this study, biopolymers-based membranes from bacterial cellulose (BC) and collagen (COL) associated with osteogenic growth peptide (OGP(10-14)) were evaluated to determine in vitro osteoinductive potential in early osteogenesis; moreover, histological study was performed to evaluate the BC-COL OGP(10-14) membranes on bone healing after GBR in noncritical defects in rat femur. The results showed that the BC-COL and BC-COL OGP(10-14) membranes promoted cell proliferation and alkaline phosphatase activity in osteoblastic cell cultures. However, ECM mineralization was similar between cultures grown on BC OGP(10-14) and BC-COL OGP(10-14) membranes. In vivo results showed that all the membranes tested, including the peptide-free BC membrane, promoted better bone regeneration than control group. Furthermore, the BC-COL OGP(10-14) membranes induced higher radiographic density in the repaired bone than the other groups at 1, 4 and 16 weeks. Histomorphometric analyses revealed that the BC-COL OGP(10-14) induced higher percentage of bone tissue in the repaired area at 2 and 4 weeks than others membranes. In general, these biopolymer-based membranes might be potential candidates for bone regeneration applications.

BONEFILL ® block as alternative for bone substitute: a toxicological evaluation

ABSTRACT Bone substitutes based on hydroxyapatite (HA) and Bonefill® (BO - inorganic bovine bone) associated with poly(lactic-co-glycolic acid) (PLGA) (HA/PLGA and BO/PLGA) were evaluated concerning cytotoxicity, genotoxicity and mutagenicity as potential candidates for bone repair. The materials were developed and provided by Bionnovation Biomedical Products Ltda. Eluates from these bone substitutes were prepared for toxicity evaluations using eukaryotic cell cultures. HA/PLGA was used as a comparison for Bonefill®. Cell viability was evaluated by XTT assay and surviving fraction was calculated for clonogenic survival. Additionally, tail moment was used to assess genotoxicity (comet assay). The frequencies of binucleated cells with micronucleus (FBMN), micronucleus (FMN), nucleoplasmic bridges (NPBs), and nuclear buds (NBUDs) were analysed by cytokinesis-block micronucleus assay (CBMN assay). Results showed no statistical difference in cell viability compared with negative control (NC) The eluates did not promote delayed cytotoxicity whereas the surviving fraction rate for cultured cells was similar to NC. Furthermore, no genotoxicity or mutagenicity effects were observed for cultured cells with the Bonefill/PLGA and HA/PLGA eluates. In conclusion, the negative cytotoxicity, genotoxicity and mutagenicity results indicate that these bone substitutes presented interesting preliminary results as potential biomaterials for bone repair.

Adhesives based on butyl-cyanoacrylate for fixation of autologous bone graft: Pilot study in rabbits.

BACKGROUND/AIM: Injuries to bone during trauma may require bone grafts and/or fixation to ensure optimal healing. Autologous bone grafts are still very common, but little data exist regarding the most effective means of fixation of such grafts. The aim of this study was to compare the fixation of autologous bone grafts with titanium screws and adhesives based on n-butyl-cyanoacrylate. MATERIAL AND METHODS: Twenty adult rabbits were used. In group I, the graft was fixed with titanium screws (in one side of the animal head), while in groups II and III (in other spots in the same animal head), the graft was fixed with adhesive Tissuacryl® and Histoacryl®, respectively. The animals were sacrificed on post-operative days 7, 15, 30, 60, and 120. Histological and histomorphometric analyses were performed. RESULTS: Inflammatory reactions were observed in all groups at 7 days. At 15 days, group I showed no inflammatory reaction. There was new bone formation in group I at 30 days and at 60 days in groups II and III. After 120 days, the grafts were completely incorporated in group I and partially incorporated in groups II and III. Groups II and III presented less graft resorption at the final evaluation: 32.58 (±10.22) and 34.75 (±8.25), compared to 26.58 (±6.48) for group I (P=.001). CONCLUSIONS: The adhesives were compatible when they were in contact with bone structures, and they were effective in fixing the grafts. Groups II and III had less graft resorption.

Role of Osteogenic Growth Peptide (OGP) and OGP(10-14) in Bone Regeneration: A Review.

Bone regeneration is a process that involves several molecular mediators, such as growth factors, which directly affect the proliferation, migration and differentiation of bone-related cells. The osteogenic growth peptide (OGP) and its C-terminal pentapeptide OGP(10-14) have been shown to stimulate the proliferation, differentiation, alkaline phosphatase activity and matrix mineralization of osteoblastic lineage cells. However, the exact molecular mechanisms that promote osteoblastic proliferation and differentiation are not completely understood. This review presents the main chemical characteristics of OGP and/or OGP(10-14), and also discusses the potential molecular pathways induced by these growth factors to promote proliferation and differentiation of osteoblasts. Furthermore, since these peptides have been extensively investigated for bone tissue engineering, the clinical applications of these peptides for bone regeneration are discussed.

Bacterial cellulose-hydroxyapatite composites with osteogenic growth peptide (OGP) or pentapeptide OGP on bone regeneration in critical-size calvarial defect model.

This study aimed to evaluate the potential of bacterial cellulose-hydroxyapatite (BC-HA) composites associated with osteogenic growth peptide (OGP) or pentapeptide OGP(10-14) in bone regeneration in critical-size calvarial defects in mice. In this study, the BC-HA, BC-HA-OGP, and BC-HA-OGP(10-14) membranes were analyzed at 3, 7, 15, 30, 60, and 90 days. In each period, the specimens were evaluated by micro-computed tomography (µCT), descriptive histology, gene expression of bone biomarkers by qPCR and VEGFR-2 (vascular endothelial growth factor) quantification by ELISA. Three days post-operative, Runx2, Tnfrsf11b and Bglap bone biomarkers were upregulated mainly by BC-HA OGP and BC-HA OGP(10-14) membranes, suggesting an acceleration of the osteoblast differentiation/activity with the use of these biomaterials. At 60 and 90 days, a high percentage of bone formation was observed by µCT for BC-HA and BC-HA OGP(10-14) membranes. High expression of some bone biomarkers, such as Alpl, Spp1, and Tnfrsf11b, was also observed for the same membranes on days 60 and 90. In conclusion, the BC-HA membrane promoted a better bone formation in critical-size mice calvarial defects. Nevertheless, incorporation of the peptides at the concentration of 10(-9) mol L(-1) did not improve bone regeneration potential in the long-term.

Antimicrobial Brazilian Propolis (EPP-AF) Containing Biocellulose Membranes as Promising Biomaterial for Skin Wound Healing.

Among remarkable discoveries concerning propolis, such as antifungal, antiviral, and antioxidant activities, its anti-inflammatory, and mainly its antibacterial, properties deserve special attention when skin wound healing is concerned. Based on this and knowing the distinctive performance of bacterial (BC) membranes on wound healing, in this work it is proposed to demonstrate the potent antimicrobial activity and wound healing properties of a novel propolis containing biocellulose membrane. The obtained propolis/BC membrane was able to adsorb propolis not only on the surface, but also in its interstices demonstrated by scanning electron microscopy, X-ray diffraction, Fourier transform infrared (FT-IR) spectroscopy, and thermogravidimetric assays. Additionally, the polyphenolic compounds determination and the prominent antibacterial activity in the membrane are demonstrated to be dose dependent, supporting the possibility of obtaining propolis/BC membranes at the desired concentrations, taking into consideration its application and its skin residence time. Finally, it could be suggested that propolis/BC membrane may favor tissue repair in less time and more effectively in contaminated wounds.

Singlet oxygen generation enhanced by silver-pectin nanoparticles.

We demonstrate the potential application of silver-pectin nanoparticles on photodynamic therapy, on a solution-base platform. Photodynamic therapy is a medical technique which uses a combination of photosensitizing drugs and light to induce selective damage on the target tissue, by electronically excited and highly reactive singlet state of oxygen. Metal enhanced singlet oxygen generation in riboflavin water solution with silver-pectin nanoparticles was observed and quantified. Here 13 nm silver nanospheres enclosed by a pectin layer were synthesized and it interaction with riboflavin molecule was analyzed. Pectin, a complex carbohydrate found in plants primary cell walls, was used to increase the biocompatibility of the silver nanoparticles and to improve metal enhanced singlet oxygen generation (28.5 %) and metal-enhanced fluorescence (30.7 %) processes at room temperature. The singlet oxygen sensor fluorescent green reagent was used to quantify the enhancement of the riboflavin singlet oxygen production induced by the silver colloid. We report a 1.7-fold increase of riboflavin emission and a 1.8-fold enhancement of singlet oxygen production.

Estudo microbiológico comparativo entre sabão de clorexidina 2% e um novo sabão antisséptico para lavagem pré-operatória das mãos / Microbiological study comparing 2% chlorhexidine soap and a new antiseptic soap for preoperative handwashing

Objetivos: avaliar, por meio de estudo microbiológico, dois tipos de sabão propostos para a lavagem das mãos na preparação dos cirurgiões no tempo pré-operatório; comparando um sabão com potência antibacteriana já conhecida e um novo sabão formulado a partir de óleos vegetais. Materiais e métodos: Dez voluntários fizeram a escovação das mãos, segundo protocolos pré-estabelecidos para a rotina de medidas de antissepsia em centros cirúrgicos, com 3 sabões diferentes, sendo um sabão comum (comercial) sem poder antisséptico que serviu como Grupo Controle (I), um sabão de digluconato de clorexidina a 2% (Grupo II) e um novo sabão feito a partir de óleos vegetais numa concentração de 20%, que foi desenvolvido pelo Instituto de Química Unesp/araraquara no Grupo de Materiais Fotônicos, denominado surfactante a 20% (Grupo III). antes de lavar as mãos, logo após e uma hora depois com o uso de luvas cirúrgicas, foi realizada a coleta microbiológica. Resultados: Pelos resultados da aNoVa, verificam-se as seguintes diferenças significativas para o número de colônias bacterianas: entre tipos de sabão (menor número de colônias no sabão do Grupo II), entre tempos (redução do número de colônias no sabão do Grupo II) e efeito significativo da interação sabão versus tempo. Conclusão: o sabão de digluconato de clorexidina 2% mostrou um comportamento melhor em reduzir o número de colônias bacterianas das mãos imediatamente após a lavagem e continuou sendo superior após uma hora com o uso de luvas, quando comparado ao sabão de surfactante a 20%.

Objective: To evaluate, by means of a microbiologic study, two kinds of soaps suggested by surgeons for presurgical handwashing, comparing a well-known antibacterial soap with a new soap formulated from vegetable oils. Materials and methods: Ten volunteers performed handwashing according to previously established protocols for routine antisepsis in operating rooms using 3 different soaps: a common, commercially marketed soap, serving as the control group (Group 1), with no antibacterial characteristics; a soap with 2% chlorhexidine (Group II); and a new soap formulated from vegetable oils at a concentration of 20%, known as surfactant, which was designed by the Chemistry Institute (Unesp/Araraquara - Grupo de Materiais Fotônicos) (Group III). The microbiological samples were collected immediately before and after handwashing and one hour later with the volunteer wearing surgical gloves. Results: ANOVA revealed that the following significant differences are found in the number of bacterial colonies: between soap types (a smaller number of colonies in the Group II soap), between periods (reduction in the number of colonies in the Group II soap), and the significant effect of the soap versus time interaction. Conclusion: The 2% chlorhexidine soap performed better in reducing the number of bacterial colonies on the hands immediately after handwashing and after one hour with the use of surgical gloves, when compared to the 20% surfactant soap.

Characterization and in vitro evaluation of bacterial cellulose membranes functionalized with osteogenic growth peptide for bone tissue engineering.

The aim of this study was to characterize the physicochemical properties of bacterial cellulose (BC) membranes functionalized with osteogenic growth peptide (OGP) and its C-terminal pentapeptide OGP[10-14], and to evaluate in vitro osteoinductive potential in early osteogenesis, besides, to evaluate cytotoxic, genotoxic and/or mutagenic effects. Peptide incorporation into the BC membranes did not change the morphology of BC nanofibers and BC crystallinity pattern. The characterization was complemented by Raman scattering, swelling ratio and mechanical tests. In vitro assays demonstrated no cytotoxic, genotoxic or mutagenic effects for any of the studied BC membranes. Culture with osteogenic cells revealed no difference in cell morphology among all the membranes tested. Cell viability/proliferation, total protein content, alkaline phosphatase activity and mineralization assays indicated that BC-OGP membranes enabled the highest development of the osteoblastic phenotype in vitro. In conclusion, the negative results of cytotoxicity, genotoxicity and mutagenicity indicated that all the membranes can be employed for medical supplies, mainly in bone tissue engineering/regeneration, due to their osteoinductive properties.

Evaluation of n-butyl cyanoacrylate adhesive in rat subcutaneous tissue.

BACKGROUND: Tissue adhesives have been widely used for wound closure, especially in children, because they are painless, fast, and easy to use and result in minimal scarring. OBJECTIVE: To analyze the biocompatibility of an adhesive based on n-butyl-cyanoacrylate in the subcutaneous tissue of rats. MATERIALS AND METHODS: Two surgical sites were prepared (approximately 3 cm apart): one on the left side of the animal and the other on the right side); polyethylene tubes were implanted in each surgical site. The tube on the left was filled with n-butyl-cyanoacrylate (treated group) and the tube on the right side was unfilled (control group). After 7, 30, and 120 days, the animals were killed, and the specimens were processed for histologic analysis. RESULTS: No significant inflammatory reaction occurred in the treated group, showing results similar to the control group. CONCLUSION: This adhesive based on n-butyl-cyanoacrylate is biocompatible in the subcutaneous tissue of rats.

Adesivos à base de cianoacrilato para síntese de tecido mole / Cyanoacrylate adhesives for the synthesis of soft tissue

Fundamentos - Adesivos teciduais têm sido muito usados para síntese de ferida, em função de ser um método indolor, rápido e de fácil execução. Objetivos-Analisar e comparar compatibilidade dos adesivos, etil- cianoacrilato (Super Bonder) e butilcianoacrilato (Histoacryl), e a reparação de incisões em dorso de ratos entre o fio de sutura e os respectivos adesivos. Métodos - Foram usados 15 ratos. Realizaram-se duas lojas cirúrgicas no dorso. Em cada uma, foi implantado um tubo de polietileno (10mm x 1mm), os quais foram preenchidos com os adesivos Super Bonder (lado direito) e Histoacryl (lado esquerdo). As incisões, do lado esquerdo, foram coaptadas com Super Bonder, e as do lado direito, com Histoacryl. Uma incisão mediana, entre as duas incisões,foi realizada e suturada com fio de seda. Os animais foram mortos, depois de 7(sete), 35(trinta) e 120 (cento e vinte dia) dias. Resultados: Os adesivos usados, no presente estudo, não promoveram reação inflamatória, quando usados para síntese das incisões. Porém, estes adesivos, quando implantados no subcutâneo, promoveram reação inflamatória até 120 (cento e vinte dia) dias, no entanto, a reação é mais intensa com Histoacryl. Conclusões: Super Bonder e Histoacryl permitem o processo cicatricial dos tecidos incisados; facilitam a sutura das incisões. Desta forma, estes podem ser utilizados para sínteses de feridas, lacerações ou incisões cutâneas.

Background: Tissue adhesives have been used for the synthesis of wound due to their painless application and quick and easy handling. Objectives: The purpose of this study was to analyze and compare the compatibility of the adhesives ethylcyanoacrylate (Super Bonder) and butyl-cyanoacrylate (Histoacryl), and to compare the reparation of incisions in the dorsum of rats with suture and the respective adhesives. Methods: Fifteen rats were used. Two surgical pockets were created in their dorsum. A polyethylene tube (10mm x 1mm) was implanted in each one. Each tube was filled with the adhesives Super Bonder(left side) and Histoacryl (right side). The incisions on the left side were closed with Super Bonder, and the incisions on the right side, with Histoacryl. A median incision between the two other incisions was made and closed with braided silk suture. The animals were killed after, 7, 35 and 120 days. Results: The adhesives used in the present study did not promote inflammatory reaction when used for the synthesis of incisions. However, when implanted subcutaneously, they caused an inflammatory reaction within 120 days. Reaction is more severe with Histoacryl. Conclusions: Super Bonder and Histoacryl can be used effectively in the healing of incised tissues; they aid in the suture of incisions. However, these adhesives can be used for the synthesis of wounds, lacerations or cutaneous incisions.

Cloridrato de tramadol/paracetamol no controle da dor pós-operatória em cirurgias de terceiros molares inclusos / Tramadol/acetaminophen in the control of postoperative pain for impacted third molar surgery

Este estudo comparou a eficácia analgésica dos fármacos tramadol/paracetamol, paracetamol e dipirona no tratamento de pacientes submetidos à extração de terceiros molares inclusos. Trinta pacientes foram selecionados. Em cada paciente, dois terceiros molares inclusos foram extraídos do mesmo lado. Para avaliar a eficácia dos analgésicos, estes foram divididos em 3 grupos: A (tramadol/paracetamol), B (dipirona) e C (paracetamol), sendo administrados de forma duplo-cega; 1 comprimido a cada 6 horas, durante 48 horas. A intensidade da dor foi avaliada por uma escala visual analógica (escore 0 ? 4: sem dor ? insuportável). A análise estatística foi realizada no software InStat, nível de significância de a=0,05. O teste de Kruskal-Wallis mostrou que os três fármacos apresentaram o mesmo resultado durante a primeira etapa de aferição (P=0,135). O teste de Friedman revelou uma diminuição no nível da dor com o passar do tempo, sendo essa diminuição similar para 3 analgésicos. Entre a primeira e a última aferição, foi observada uma diferença estatisticamente significante para os analgésicos A e B, mas não, para o C. Concluímos que o tramadol/paracetamol foi eficaz no controle de dor pós-operatória de extração de terceiro molar incluso e que a dipirona foi tão eficaz quanto o tramadol/paracetamol. O paracetamol, entrentanto, possui um menor efeito em relação aos outros analgésicos.

This study compared the effectiveness of the three analgesics in the control of postoperative pain in impacted third molar surgeries. Thirty patients were selected who needed removal of only two impacted third molars at the same side. Randomized, double-blind trials were applied to evaluate the efficacy of analgesics. Analgesics were divided in: A (tramadol/acetaminophen), B (sodic dipyrone) e C (acetaminophen) -1 tablet each 6 hours during 48 hours. The intensity of the pain was evaluated by the patients according with a visual analogical scale (score 0 ? 4: no pain ?insupportable). Statistical analysis at InStat software, the significance level of a=0.05. Kruskal-Wallis test showed that the three medicaments presented the same result during the first stage of measurements (P=0.135). Friedman test showed a decrease in the level of pain with passing of the time, being this decrease similar for the three analgesics. A significant difference between first and the last gauging could be observed for the A and B analgesics. The same trend could be seen for drug C, although not to reach significance statistics. Tramadol/acetaminophen was efficient in the control of postoperative pain in impacted third molars surgeries, when it compared with dipyrone and acetaminophen.

Adesivos de cianoacrilato para fixação de xenoenxertos / Cyanoacrylate adhesives for fixation of xenografts

O objetivo deste trabalho foi o de avaliar histologicamente os adesivos à base de etil-cianoacrilato e de butil-2-cianoacrilato na fixação de enxertos ósseos bovinos, em osso parietal de coelho. Vinte coelhos adultos receberam enxerto de osso bovino inorgânico liofilizado em bloco, sobre osso parietal. Previamente, foram realizadas osteotomias no osso bovino, com uma trefina de 6 mm. Os enxertos foram fixados com etil-cianoacrilato no grupo I (GI) e, com butil-2-cianoacrilato, no grupo II (GII). Após 5, 15, 30, 60 e 120 dias, os animais foram sacrificados, e as peças foram processadas segundo técnica histológica para coloração em H.E. Em 15 dias, em GI e GII, foram observadas discreta reação inflamatória. Notou-se presença de neoformação óssea adjacente ao enxerto em 30 dias, no GI e aos 60 dias, no GII. Aos 120 dias, tecido conjuntivo no interior do enxerto, pontos de neoformação óssea, presença de adesivo e os enxertos não se apresentaram incorporados ao leito receptor em todos os espécimes (GI e GII). Concluímos que tanto etil-cianoacrilato quanto butil-2-cianoacrilato foram biocompatíveis. Ambos os adesivos fixaram os xenoenxertos, promovendo estabilidade adequada para neoformação óssea no interior do enxerto e na interface enxerto/leito receptor, no entanto uma avaliação adicional a longo prazo é necessária para verificar a degradação completa dos adesivos.

The aim of this study was to histologically evaluate ethyl-cyanoacrylate and butyl-2-cyanoacrylate adhesives for fixation of bovine bone grafts on parietal bone of the rabbit. Twenty adult rabbits received a graft of freeze-dried inorganic bovine bone on parietal bone. Prior to the graft, osteotomies were performed on bovine bone with a 6mm-trephine. The grafts were fixed with ethyl-cyanoacrylate in group I (GI) and with butyl-2-cyanoacrylate in group II (GII). The animals were sacrificed after 5, 15, 30, 60 and 120 days and the specimens submitted to the routine laboratory procedures for H.E. staining. At 15 days, a slight inflammatory reaction was observed in both GI and GII. The presence of new bone formation around the graft was noted at 30 days in GI and at 60 days in GII. After 120 days, there was connective tissue within the graft, regions of new bone formation and presence of adhesive, none of the grafts being incorporated into the host bed in either GI or GII. We concluded that both ethyl-cyanoacrylate and butyl-2-cyanoacrylate were biocompatible and both adhesives fixed the xenografts, providing adequate stability for new bone formation inside the graft and on the graft/host bed interface. However, an additional evaluation long-term is necessary to verify the complete degradation of the adhesives.

[Cyanoacrylate adhesives for the synthesis of soft tissue]. / Adesivos à base de cianoacrilato para síntese de tecido mole.

BACKGROUND: Tissue adhesives have been used for the synthesis of wound due to their painless application and quick and easy handling. OBJECTIVES: The purpose of this study was to analyze and compare the compatibility of the adhesives ethylcyanoacrylate (Super Bonder) and butyl-cyanoacrylate (Histoacryl), and to compare the reparation of incisions in the dorsum of rats with suture and the respective adhesives. METHODS: Fifteen rats were used. Two surgical pockets were created in their dorsum. A polyethylene tube (10mm x 1mm) was implanted in each one. Each tube was filled with the adhesives Super Bonder(left side) and Histoacryl (right side). The incisions on the left side were closed with Super Bonder, and the incisions on the right side, with Histoacryl. A median incision between the two other incisions was made and closed with braided silk suture. The animals were killed after, 7, 35 and 120 days. RESULTS: The adhesives used in the present study did not promote inflammatory reaction when used for the synthesis of incisions. However, when implanted subcutaneously, they caused an inflammatory reaction within 120 days. Reaction is more severe with Histoacryl. CONCLUSIONS: Super Bonder and Histoacryl can be used effectively in the healing of incised tissues; they aid in the suture of incisions. However, these adhesives can be used for the synthesis of wounds, lacerations or cutaneous incisions.

Implantes intra-ósseos de material à base de ácido poliláctico em mandíbula de coelhos. Estudo histológico / The use of polylactic acid implants in surgical defects of rabbits mandibles. Histological analysis

Materiais biodegradáveis usados em cirurgia óssea têm sido pesquisados há mais de três décadas. Os implantes biodegradáveis mais comumente testados são os ácidos polilácticos e sua biocompatibilidade é considerada de excelência. Outros estudos demonstraram apenasbiodegradação parcial que resultou em respostas teciduais de processos inflamatórios em longo prazo. Objetivo: o presente estudo tem a finalidade de avaliar histologicamente o comportamento de um material a base de ácido poliláctico após sua implantação em cavidades ósseas em mandíbulade coelhos. Material e método: a amostra foi constituída de 16 coelhos adultos que foram divididos em dois grupos. Grupo I: cavidades ósseas cirúrgicas preenchidas com material à base de ácidopoliláctico que foi utilizado como grupo teste; e Grupo II; cavidades ósseas cirúrgicas preenchidas com coágulo sangüíneo, perfazendo o grupo controle. Após 15, 30, 60 e 90 dias, os animais foramsacrificados e as mandíbulas processadas segundo rotina laboratorial histológica para coloração em H.E. Resultado: aos 15 dias, o material encontra-se com reação inflamatória intensa e iníciode formação de cápsula fibrosa. Aos 30 dias o material permanece na cavidade e observa-se início de formação óssea advinda da parede da cavidade. Aos 60 dias, ausência de infiltrado inflamatórioe presença de osso neoformado ao redor do implante. Aos 90 dias, o osso neoformado apresenta aspecto organizado e mais maduro. Conclusão: o material à base de ácido poliláctico implantadomostrou-se biocompatível, sendo bem aceito pelo tecido ósseo adjacente ao implante. Porém não sofreu processo de degradação ou reabsorção nos períodos avaliados.

The biodegradable materials used in bone surgery have been researched for more than three decades. The most commonly tested bioresorbable implants are the polylactic acids which present excellent biocompatibility. On the other hand, some studies showed only partial degradation and variable long-term tissue reactions. Objective: This study evaluated the histological behavior of a polylactic acid-based material after implantation into extensive and deep surgical cavities in rabbit mandibles. Material and method: Sixteen adult rabbits were used in this study. Ineach animal a surgical cavity was prepared in the mandible. The sixteen rabbits were divided into two groups: Group I- surgical cavities filled with polylactic acid material and, Group II- surgical cavities filled with blood clot as controls. After fifteen, thirty, sixty and ninety days the animalswere sacrificed and the mandibles were dissected for histological processing and analysis. Results: After 15 days, the implant showed inflammatory reaction and capsule formation. After 30 days,the material remained in the surgical cavity without degradation and beginning of bone formation was observed. At sixty days, the inflammatory process was absent and the material was surroundedby bone. At 90 days, lamellar bone was formed. Conclusion: The polydactyl acid implants were biocompatible and well accepted by the adjacent bone. However, with ninety days the materialstill remained in the surgical cavity without degradation.

Implantes de polietileno poroso em calota de coelho: análise histológica comparativa / Porous Polyethylene Implants in Rabbit Calvarium: Histological Comparasion

O objetivo deste estudo foi comparar histologicamente o comportamento de implantes nacionais de polietilenoporoso (Polipore®) e de enxerto ósseo autógeno em defeitos ósseos em osso parietal de coelho. Foram utilizados 20 coelhos, os quais receberam osteotomias parietais bilaterais com o auxílio de uma trefina de 6mm dediâmetro. No Grupo I (GI), a cavidade foi preenchida com enxerto ósseo retirado do lado oposto, e, no GrupoII (GII), a cavidade foi preenchida com Polipore®. Não foram utilizados meios de fixação para os enxertos e implantes. Após 5, 15, 30, 60 e 120 dias, ocorreu a eutanásia dos animais, e as calotas cranianas foram processadas, segundo rotina histológica para coloração em H.E. Observou-se reação inflamatória discreta no(GI) aos 5 dias e moderada no GII, persistindo até aos 30 dias no GII. Os enxertos ósseos apresentaram-se incorporados ao leito receptor aos 120 dias. E somente aos 120 dias, no GII, observou-se presença de tecido conjuntivo no interior dos poros do implante. Concluímos que os enxertos foram eficientes na reparação do defeito ósseo, devido à incorporação ao leito receptor; O Polipore® foi biocompatível, mas não possui quantidadee tamanho de poros adequados para permitir o crescimento fibrovascular no interior do material

The aim of this study was to histologically compare national porous polyethylene implants and autogenous bone graft in cranial vault defects in rabbits. Cranial vaults defects were surgically created with a trephineburr of 6mm diameter in the parietal bones of 20 rabbits. In group I (GI) the bone defects were filled with autogenous bone graft from the contralateral parietal side, and in group II (GII), the bone defects were filledwith Polipore®. The grafts and implants were not fixed on the site. After 5, 15, 30, 60 and 120 days the animals were sacrificed and the cranial vaults were processed according to histological routine for stainingwith H&E. On the 5th day a discreet inflammatory reaction was observed in GI , while in GII, a moderate, inflammatory reaction persisted up to the 30th day. The bone grafts were incorporated to the host bedwithin 120 days. Only then, connective fibrous tissue was observed into the pores of the implant in GII. Bone grafts can efficiently repair bone defects, due to their incorporation into the bone host bed; the Polipore®implant is biocompatible, but does not have the adequate quantity and size of pores to permit fibrovascular tissue ingrowth into the material