The impact of synthetic bone grafting for tissue regeneration: an in vivo study

Aims: This study aimed to examine the biological response of synthetic nanocomposite material on canine mandibular bone. Methods: Nine healthy adult male local breed dogs aged 12 to 18 months and weighing 10.2 to 15.2 kg were used in the study. Based on healing intervals of 1 and 2 months, the dogs were divided into 2 groups. Each group had 3 subgroups with 3 dogs each. The division was based on the grafting material used to fill the created defect: an empty defect (Control-ve), Beta-Tricalcium Phosphate, and nanocomposite (Beta-Tricalcium Phosphate and nanosilver 1%) . Surgery started after the dogs were anaesthetized. The surgical procedure began with a 5 cm parallel incision along the mandible's lower posterior border. After exposing the periosteum, a three 5mm-diameter, 5-mmdeep critical-size holes were made, 5mm between each one. Each group's grafting material had independent 3 holes. The defects were covered with resorbable collagen membranes followed by suturing of the mucoperiosteal flap. Results: Total densitometric analysis showed no significant differences between groups at 1-month intervals, with the nanocomposite group having a higher mean rank (165.66± 31.21) in comparison to other groups while at 2 months intervals that there was a highly significant difference between three groups as the P-value was (0.000) with the nanocomposite group having a higher mean rank (460.66± 26.40). Conclusions: In the current study, the use of nanocomposites improved osteoconductivity by accelerating new bone formation. Moreover, the encorporation of nanosilver enhanced growth factor activity. These attributes make nanocomposites a promising material for enhancing the bone healing process

Apical Periodontitis Healing Following Treatment is Impacted by Root Canal Sealer Composition: An in Vivo and in Vitro Investigation

Abstract Objective: To evaluate the periapical healing following root canal treatment in teeth with apical periodontitis (in vivo) and the cytotoxic potential of root canal sealers in vitro. Material and Methods: Apical periodontitis was induced in 60 dogs' teeth and root canals were filled with Sealapex (40 roots), EndoREZ (40 roots), intracanal dressing (20 roots), or left untreated (20 roots). After 30 and 90 days, histopathological analyses were made. In vitro, J774.1 macrophages were stimulated with root canal sealers extracts, cytotoxicity was assessed using lactate dehydrogenase assay, and qRT-PCR was used to analyze TNF-α gene expression. Results: In vivo, smaller apical periodontitis and lower inflammatory cell infiltrate were found in teeth treated with Sealapex compared to EndoREZ. In vitro, EndoREZ was cytotoxic and induced TNF-α gene expression by macrophages differently from Sealapex. Conclusion: Sealapex allowed improved tissue repair following root canal treatment in teeth with apical periodontitis compared to EndoREZ. Synthesis of TNF-α induced by LPS was enhanced by EndoREZ, whereas Sealapex prevented pro-inflammatory gene expression (AU).

In Vivo Detection of External Apical Root Resorption Induced by Apical Periodontitis Using Periapical Radiography and Cone-Beam Computed Tomography

Abstract Objective: To compare the accuracy of periapical radiography (PR) and cone-beam computed tomography (CBCT) for the detection of external apical root resorption (EARR) due to root canal contamination. Material and Methods: Dog's teeth with experimentally induced root resorption due to root canal contamination underwent or not root canal treatment (n=62). True positives (TP), false positives (FP), true negatives (TN), and false negatives (FN) in PR and CBCT diagnoses were determined using histopathologic findings as the gold standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy (TP + TN) in the diagnosis of EARR were calculated. Data were compared using chi-squared test (α=0.05). Results: EARR was detected in 35% of roots by PR, in 47% by CBCT, and in 50% of the roots by microscopy (p=0.03 PR versus microscopy; p=0.67 CBCT versus microscopy). Overall, CBCT produced more accurate diagnoses than PR (p=0.008). PR and CBCT allowed the identification of large resorption in 100% of the cases and showed the same accuracy. However, for small resorptions, PR showed an accuracy of 0.83, whereas CBCT showed an accuracy of 0.96 (p=0.003). Conclusion: Cone-beam computed tomography showed higher accuracy in detecting external apical root resorption of endodontic origin.

Histometry Analysis of Osteoclasts, Osteoblasts and Fibroblasts in Immediate Placement Implants with Addition of Aloe Vera Extract

Objective: To analyze the effect of immediate placement of implants with extract from the new bone formation histometically. Material and Methods: In this true-experimental design with randomized post test control group, 9 mongrel dogs weighing 10 to 12 kg were used, which were divided into 3 groups, based on observation time of 14 days, 28 days and 56 days. On the installation of implants (∅3.5x10 mm) sequentially, the former socket extraction of the lower jaw's right second premolar tooth in the study sample injected 10% Aloe vera gel extract and left second left premolar tooth without injection of 10% Aloe vera extract. To compare independent groups use the Mann-Whitney test. All analysis were carried out using SPSS version 20. Results: There was an increase in the number of osteoblast cells in both treatment and control groups, but the value of the treatment group was greater. There were significant differences in the number of osteoblast cells between the treatment and control groups 14 days (p=0.019), 28 days: (p=0.018), and 56 days (p=0.009). There were no significant differences in the number of fibroblast cells between the treatment and control groups (p>0.05). But at observations 28 and 56 days, it was showed a significant difference in the number of fibroblast cells between the treatment and control groups (p=0.353 and p=0.024, respectively). Conclusion: Immediate placement of implants with 10% Aloe vera extract gel on extracted socket increases the number of osteoblasts and suppresses the number of osteoclasts and fibroblasts.

A comparison of the sealing abilities between Biodentine and MTA as root-end filling materials and their effects on bone healing in dogs after periradicular surgery

ABSTRACT Objectives: To compare the sealing ability and biocompatibility of Biodentine with mineral trioxide aggregate (MTA) when used as root-end filling materials. Methodology: The Cell Counting Kit-8 (CCK-8) assay was used to compare the cytotoxicity of MTA and Biodentine. Twenty-one extracted teeth with a single canal were immersed in an acidic silver nitrate solution after root-end filling. Then, the volume and depth of silver nitrate that infiltrated the apical portion of the teeth were analyzed using micro-computed tomography (micro-CT). Seventy-two roots from 3 female beagle dogs were randomly distributed into 3 groups and apical surgery was performed. After six months, the volume of the bone defect surrounding these roots was analyzed using micro-CT. Results: Based on the results of the CCK-8 assay, MTA and Biodentine did not show statistically significant differences in cytotoxicity (P>0.05). The volume and the depth of the infiltrated nitrate solution were greater in the MTA group than in the Biodentine group (P<0.05). The volume of the bone defect was larger in the MTA group than in the Biodentine group. However, the difference was not significant (P>0.05). The volumes of the bone defects in the MTA and Biodentine groups were smaller than the group without any filling materials (P<0.05). Conclusions: MTA and Biodentine exhibited comparable cellular biocompatibility. Biodentine showed a superior sealing ability to MTA in root-end filling. Both Biodentine and MTA promoted periradicular bone healing in beagle dog periradicular surgery models.

Comparison of two soft tissue substitutes for the treatment of gingival recession defects: an animal histological study

Abstract Objectives: This study aimed to compare two different soft tissue replacement grafts in their ability to treat gingival recession defects and successfully integrate with the surrounding tissues. Methodology: Nine beagle dogs were included and followed up to 10 weeks. Sites for intervention were allocated to one of the grafting materials investigated. Treatment consisted of coronally advanced flap combined with one of the two soft tissue substitutes on a previous surgically created defect. Materials employed were porcine-derived acellular dermal matrix (ADM) [Novomatrix™ (Test)] and collagen-based matrix (CBM) [Mucograft® (Control)]. Animals were sacrificed at 2, 6, and 10 weeks postoperatively and compared using descriptive histology and histomorphometric outcomes. Results: Macroscopic findings were similar between test and control groups at all intervals. After 10 weeks, both groups demonstrated successful incorporation of the grafting materials without signs of rejection and with comparable tissue integration. The histomorphometric data were similar between groups at 2 weeks; however, the test group provided greater root coverage and increase in tissue thickness than the control at 6- and 10-weeks post surgically. Conclusions: Both porcine-derived ADM and CBM revealed similar histological outcomes with successful integration and absence of adverse events. Test group provided superior outcomes regarding root coverage and increase in tissue thickness.

Aspectos biológicos e tratamentos da reabsorção radicular externa por substituição: revisão da literatura / Biological aspects and treatment of external replacement resorption: literature review

A Reabsorção Radicular Externa por Substituição (RRES) consiste na substituição da estrutura dentária por tecido ósseo. O atual consenso é de que não há terapia pertinente para tal processo. Uma revisão de literatura com enfoque em protocolos terapêuticos utilizados em dentes traumatizados e seus efeitos sobre a RRES será apresentada. Para tal, artigos científicos na língua inglesa foram reunidos por meio das bases de dados Pubmed Central, Scopus, Embase Medline, Ovid e Cochrane, utilizando as seguintes palavras chaves: Tooth Resorption, Root Resorption, Tooth Injuries, Root Canal Therapy, Ankylosis. Estudos demonstraram que anquilose e RRES se desenvolveram nas superfícies dentárias independentemente do medicamento utilizado no interior do canal. Dentes tratados com hidróxido de cálcio e guta-percha apresentaram maior predominância de deposição óssea. Corticoides demonstraram resultados promissores, observando-se reparo favorável e menor taxa de RRES. Não foram encontrados artigos relatando tentativas interceptativas frente ao processo de reabsorção por substituição. Apesar de sua ocorrência ter se demonstrado frequente, tentativas de controle do processo instalado são relevantes, considerando- se que a ausência de tratamento resulta na pior consequência possível: a perda dentária.

Energy Dispersive Spectroscopy (EDS) Analysis of Calcium and Phosphor Minerals Elements on Bone After Insertion Immediate Implant on Socket Filled with Extract Aloe vera

Objective: To examine the effect of aloe vera that containing bioactive materials on the levels of calcium (Ca) and phosphorus (P) minerals and their ratios around the immediate implanted in alveolar bone. Material and Methods: Research method by conducting experimental test on experimental animals: 9 male mongrel dogs are divided into 3 groups each 3 tails. In each animal was pulled the second premolar teeth on right side and left side, and immediately inserted titanium implant (3mm x 10mm diameter) after the socket filled with 10% aloevera extract on the right side and control on the left side. Analysis of calcium and phosphorus minerals content formed by examination of Energy Dispersive Spectroscopy (EDS) on Scanning Electron Microscope on implant and around bone tissue was done on days 14, 28 and 56. The result of statistical analysis using repeated ANOVA with independent t test. The level of significance was set at 5%. Results: There was a significant difference on calcium level between control and treatment groups on days 14, 28 and 56 (p<0.05). There was no significant difference on phosphorus level between control and treatment groups (p>0.05). The ratio of Ca / P in both control and treatment groups was also significantly different in every observation day (p<0.05). Conclusion: The addition of aloe vera extract that containing bioactive materials has an effect on increasing levels of mineral elements calcium and calciumphosphorus ratio after immediate implant insertion.

Improved sealing ability promoted by calcium silicate-based root canal sealers

Aim: This study investigated the sealing ability produced by AH Plus (Dentsply DeTrey, Konstaz, Germany), EndoSequence BC sealer (Brasseler USA, Savannah, GA, USA), GuttaFlow (Coltène/Whaledent, Altstätten, France) and MTA Fillapex (Angelus, Londrina, Brazil). Methdos: A total of forty-six single-root human canines were prepared and randomly divided into four experimental groups (n=10): MTA Fillapex, EndoSequence BC Sealer, AH Plus or GuttaFlow. Teeth with intact crowns served as negative controls (n=3) and teeth filled with only gutta-percha served as positive controls (n=3). Teeth were mounted in a two-chamber apparatus and exposed to Enterococcus faecalis. The number of days over a 60-days period was recorded for the appearance of turbidity in the lower chamber. Kaplan-Meier method was used to estimate the survival curves. The nonparametric log-rank test was used to compare the survival curves using a significance level of 0.05. Results: The results at the end of the observation time were further analyzed by chi-square testing. All positive controls leaked within 24 h, whereas none of the negative controls leaked after 60 days. EndoSequence BC Sealer and MTA Fillapex had significant less bacterial leakage (P<0.05) than the other tested sealers. No significant difference between AH Plus and GuttaFlow was observed (P>0.05). Conclusion: In conclusion, calcium-silicate based root canal sealers promoted improved sealing ability when compared to other endodontic sealers

Apical Negative Pressure irrigation presents tissue compatibility in immature teeth

Abstract Aim: To compare the apical negative pressure irrigation (ANP) with conventional irrigation in the teeth of immature dogs with apical periodontitis. Methods: Fifty-two immature pre-molar root canals were randomly assigned into 4 groups: ANP (n=15); conventional irrigation (n=17); healthy teeth (control) (n = 10); and teeth with untreated apical periodontitis (control) (n=10). After induction of apical periodontitis, teeth were instrumented using EndoVac® (apical negative pressure irrigation) or conventional irrigation. The animals were euthanized after 90 days. The sections were stained by HE and analyzed under conventional and fluorescence microscopy. TRAP histoenzymology was also performed. Statistical analyses were performed with the significance level set at 5%. Results: There was difference in the histopathological parameters between ANP and conventional groups (p<0.05). The ANP group showed a predominance of low magnitude inflammatory infiltrate, a smaller periodontal ligament, and lower mineralized tissue resorption. There were no differences in the periapical lesion extensions between the ANP and conventional groups (p>0.05). However, a lower number of osteoclasts was observed in the ANP group (p<0.05). Conclusion: The EndoVac® irrigation system presented better biological results and more advanced repair process in immature teeth with apical periodontitis than the conventional irrigation system, confirming the hypothesis.

Diagnosis of alveolar and root fractures: an in vitro study comparing CBCT imaging with periapical radiographs

Abstract Objective To compare periapical radiograph (PR) and cone-beam computed tomography (CBCT) in the diagnosis of alveolar and root fractures. Material and Methods Sixty incisor teeth (20 higid and 40 with root fracture) from dogs were inserted in 60 anterior alveolar sockets (40 higid and 20 with alveolar fracture) of 15 macerated canine maxillae. Each fractured socket had a root fractured tooth inserted in it. Afterwards, each maxilla was submitted to PR in two different vertical angulation incidences, and to CBCT imaging with a small field of view (FOV) and high-definition protocol. Images were randomized and posteriorly analyzed by two oral and maxillofacial radiologists two times, with a two-week interval between observations. Results Sensitivity and specificity values were good for root fractures for PR and CBCT. For alveolar fractures, sensitivity ranged from 0.10 to 0.90 for PR and from 0.50 to 0.65 for CBCT. Specificity for alveolar fractures showed lower results than for root fractures for PR and CBCT. Areas under the ROC curve showed good results for both PR and CBCT for root fractures. However, results were fair for both PR and CBCT for alveolar fractures. When submitted to repeated measures ANOVA tests, there was a statistically significant difference between PR and CBCT for root fractures. Root fracture intraobserver agreement ranged from 0.90 to 0.93, and alveolar fracture intraobserver agreement ranged from 0.30 to 0.57. Interobserver agreement results were substantial for root fractures and poor/fair for alveolar fractures (0.11 for PR and 0.30 for CBCT). Conclusion Periapical radiograph with two different vertical angulations may be considered an accurate method to detect root fractures. However, PR showed poorer results than CBCT for the diagnosis of alveolar fractures. When no fractures are diagnosed in PR and the patient describes pain symptoms, the subsequent exam of choice is CBCT.

Osseointegration aspects of placed implant in bone reconstruction with newly developed block-type interconnected porous calcium hydroxyapatite

ABSTRACT Artificial bone has been employed to reconstruct bone defects. However, only few reports on implant placement after block bone grafting exist. Objectives The purpose of this study was to evaluate the osseointegration of dental implant in bone reconstructions with interconnected porous calcium hydroxyapatite (IP-CHA). Material and Methods The IP-CHA cylinders (D; 4.3 mm, H; 10.0 mm) were placed into bone sockets in each side of the femurs of four male dogs. The IP-CHA on the right side was a 24-week sample. Twelve weeks after placement, a titanium implant was placed into a socket that was prepared in half of the placed IP-CHA cylinder on the right side. On the left side, another IP-CHA cylinder was placed as a 12-week sample. After another 12 weeks, the samples were harvested, and the bone regeneration and bone-implant contact (BIC) ratios were measured. Results New bone formation area was superior in the 24-week IP-CHA compared with the 12-week IP-CHA. BIC was not significantly different between IP-CHA and the parent sites. Osseointegration was detected around the implant in IP-CHA-reconstructed bone. Conclusion Our preliminary results suggest that IP-CHA may be a suitable bone graft material for reconstructing bones that require implant placement.

Evaluation of biomaterials with and without platelet-rich plasma: a histometric study using beagle dogs

Aim: To compare the alveolar bone repair process using biomaterial in dogs with and without the incorporation of platelet-rich plasma. Methods: Six beagles were used. Bilateral extractions of the three mandibular premolars were performed. Bio-Gen® was applied in the first alveolus, the clotwas maintained in the second alveolus and Genox® was applied to the third alveolus. PRP wasadded to all alveoli on the left side only. The dogs were submitted to euthanasia after 30, 60 and90 days and submitted to histological analysis for the determination of mean area of new boneformation. Tukey’s post test was used in the statistical analysis. Results: Significant increase inbone formation occurred in Bio-Gen® + PRP when compared with the other groups at 30 and 90days. In the evaluation at 60 days, no statistically significant differences among the groups were found. Conclusions: The Bio-Gen® biomaterial led to the best bone repair and the combinationof platelet-rich plasma accelerated the repair process.

Avaliação histológica e histomorfométrica do comportamento ósseo em relação à profundidade da linha marginal de cimentação de próteses sobre implantes Cone Morse: estudo experimental em cães / Histologic and histomorphometric evaluation of bone behavior in relation to the depth of the line of marginal cementation on Morse taper implants: experimental study in dogs

A utilização dos implantes cone morse muito favorece a estética peri-implantar e seu uso em conjunto com próteses cimentadas favorece ainda mais a estabilidade do sistema, simplificando também os procedimentos protéticos. O presente estudo histológico e histomorfométrico utilizou os implantes cone morse com o intuito de avaliar o comportamento tecidual com relação à posição da margem da cimentação protética em relação ao tecido ósseo quando se faz o uso próteses cimentadas. Foram utilizados quatro cães, os quais tiveram todos os pré-molares inferiores extraídos numa primeira fase cirúrgica. Após três meses, realizou-se a segunda fase cirúrgica, na qual foi realizada a técnica da carga imediata, com a instalação dos implantes juntamente com os pilares protéticos. Foram instalados vinte e quatro implantes numa profundidade de 3 mm infra óssea e eles foram igualmente divididos entre os grupos Controle e Experimental. Os pilares protéticos utilizados foram do tipo munhão universal e apresentavam diferentes alturas transmucosas iguais a 1.5 mm, 3.5 mm, e 5.5 mm. Isto fez com que a margem da cimentação se posicionasse a 1.5 mm infra óssea, a 0.5 mm supra óssea e a 2.5 mm supra óssea. No grupo Controle, foi realizada a instalação dos implantes e dos pilares protéticos somente. No grupo Experimental, foi realizada a instalação dos implantes, dos pilares protéticos e, sobre estes, foram cimentados cilindros de alumina. Os animais permaneceram sobre controle de placa durante 10 semanas subsequentes a instalação dos implantes, sendo este o tempo final do experimento através da realização da eutanásia. As amostras foram preparadas para análise histológica e avaliação dos tecidos peri-implantares. A região de interesse foi medida através da distância entre a margem do pilar protético e a porção mais coronal da crista óssea peri-implantar. Foram utilizados os testes estatísticos ANOVA a três critérios com medidas repetidas e teste de Tukey com o nível de significância de...

The use of Morse taper implants has increased because of some positive features. Cemented crowns can be extensively used, taking advantage of the system connection stability, also simplifying the prosthetic procedures. The present histological and histomorphometric study used Morse taper implants with the purpose of evaluating bone behavior with respect to the cementation margin position of the prosthetic crown. Four dogs had all premolars extracted at a first surgical procedure. After three months, there was a second surgical procedure with simultaneous installation of implants and abutments, submitted to immediate load. Twenty four implants were installed 3 mm below the bone level and they were equally divided between Control and Experimental groups. The universal post abutments used had three different transmucosal heights, 1.5 mm, 3.5 mm and 5.5 mm. Thus there were implants with the level of the cementation margin positioned 1.5 mm below the bone level, as well as 0.5 mm and 2.5 mm above the bone level. In the Control group, installation of implants and abutments only was performed. In the Experimental group immediately after the placement of implants and abutments alumina cylinders were cemented. The animals were kept on plaque control for 10 weeks after implant placement and then euthanized. Samples were prepared for histological analysis and evaluation of peri-implant tissues. The region of interest was measured by the distance between the prosthetic margin of the abutment to the most coronal peri-implant bone crest. ANOVA test at three criteria with repeated measures and Tukey test with a significance level of p < 0.05 were applied. The results showed no statistically significant differences between Control and Experimental groups (p = 0.2764). The 1.5 mm abutments presented less bone loss compared to all other abutments tested, because the distance average of bone remodelation was shorter in this group (0.6859 mm) compared to the...

O uso de biomateriais de origem bovina e equina, associados ou não ao plasma rico em plaquetas, em alvéolos mandibulares de cães: estudo split-mouth com análise quantitativa / The use of bovine and equine biomaterials associated or not to platelet-rich plasma in mandibular alveolar dog model: a quantitative analysis

Objetivo: avaliar biomateriais de origem equina (Bio-Gen) e bovina (Genox), associados ou não ao plasma rico em plaquetas (PRP). Material e métodos: seis cães Beagle, fêmeas (entre dois e três anos de idade, pesando 10 kg), tiveram seis pré-molares mandibulares extraídos. No lado direito, os alvéolos receberam Bio-Gen (B), coágulo (C) e Genox (G); no lado esquerdo, o PRP foi adicionado em cada grupo (BP, CP e GP). Após 30, 60 e 90 dias, dois cães foram sacrificados em cada período, e as peças foram processadas. As imagens microscópicas e a contagem dos osteoblastos aderidos às trabéculas ósseas e osteócitos presentes em lacunas no tecido ósseo neoformado foram realizadas pelo mesmo operador. Os testes Anova e Tukey (nível de significância de 5%) foram empregados na análise estatística. Resultados: para a contagem de osteoblastos, aos 30 dias, houve diferença estatisticamente significante dos grupos G e GP, quando comparados aos grupos B, BP, C e CP (p < 0,05). Na análise de 60 dias, os grupos BP e GP apresentaram diferença estatisticamente significativa, quando comparados aos grupos B (p < 0,001) e G (p < 0,000001), respectivamente. Para a contagem de osteócitos, aos 30 dias, houve diferença estatisticamente significante quando os grupos BP e GP foram comparados aos grupos B (p < 0,00001) e G (p < 0,002), respectivamente. Os grupos GP e G apresentaram diferença estatisticamente significativa entre si, em 60 dias (p < 0,0009) e 90 dias (p < 0,0004). Conclusão: o grupo GP apresentou maior quantidade de osteócitos e osteoblastos em todos os períodos analisados, sendo considerado o mais efetivo para a neoformação óssea.

Substitutos ósseos – equino e bovino – associados ou não ao PRP em cavidades mandibulares de cães Beagle: estudo split-mouth qualitativo / Bone substitutes – equine and bovine – associated or not to PRP in Beagle dog’s mandibular cavities: split-mouth qualitative study

Objetivo: avaliar o processo de reparo ósseo usando os biomateriais GenOx e Bio-Gen, associados ou não ao PRP, comparando os osteocondutores entre si e a inserção do PRP qualitativamente. Material e métodos: foram utilizados seis cães fêmeas da raça Beagle, dois anos de idade, 10 kg. Foram confeccionados seis defeitos ósseos circulares com 6 mm de diâmetro em corpo de mandíbula, sendo três cavidades na hemimandíbula direita e três na porção esquerda. Cada cavidade em ambos os lados foi preenchida com os diferentes materiais: Bio-Gen, controle (coágulo), e GenOx isoladamente. Do lado esquerdo da mandíbula as cavidades sofreram adição de PRP. Nos intervalos de 30, 60 e 90 dias foram coletadas amostras e o material foi submetido à rotina histológica. Realizou-se análise qualitativa por meio da observação do processo de reparo com magnificação de 20x. Resultados: notou-se reparo mais evoluído no grupo Bio-Gen + PRP, quando comparado aos demais. Os grupos com a adição de PRP nos biomateriais demonstraram osso secundário aos 30, 60 e 90 dias. Conclusão: o osso equino apresentou os melhores resultados quanto à formação de osso maduro, e sua eficácia foi superior quando associado ao PRP.

to evaluate the bone repair process with GenOx and Bio-Gen biomaterials, associated or not to PRP, from the qualitative aspect. Material and Methods: six female beagle dogs (2 years-old, 10kg) were used. Six circular bone defects (6mm in diameter) were prepared, being three on the left and three on the right mandibular side. Each cavity on both sides was filled with: Bio-Gen, coagulum (control), and Gen-Ox, being one side receiving PRP. Samples were collected at 30, 60, and 90 days for histological quantitative analysis at 20x magnification. Results: the Bio-Gen+PRP group demonstrated more advanced repair when compared to the other groups. The use of PRP generated secondary bone at all time periods. Conclusion: the equine substitute bone presented the best results regarding mature bone formation, given its efficacy enhanced by PRP

Uso do PRP com enxertos autógeno e de banco de tecido ósseo para levantamento do seio maxilar em um modelo em cães: desenho tipo split-mouth com resultados microscópico / The use of PRP with autogenous and tissue bone bank grafting for sinus lift procedures in the dog model: split-mouth design with microscopic results

Objetivo: avaliar microscopicamente a contribuição do plasma rico em plaquetas (PRP) no processo de reparo do enxerto ósseo de banco de ossos humanos e de osso autógeno em seios maxilares de cães. Material e métodos: quatro cães da raça Beagle, com dois anos de idade e aproximadamente 10 kg, foram submetidos a cirurgias de levantamento de seio maxilar utilizando-se enxerto ósseo autógeno (lado direito) como grupo-controle e enxerto de banco de ossos humanos (lado esquerdo) associados ao PRP em dois cães, e sem nos outros. As amostras para análise foram removidas com broca trefina no período de 60 dias pós-enxertia. Resultados: o enxerto autógeno mostrou processo de reparo em desenvolvimento; quando associado ao PRP apresentou organização lamelar e presença de medula óssea. No enxerto alógeno foram observadas fibrilas colágenas desorganizadas com grande quantidade de osteócitos; quando associado ao PRP, notou-se ausência de infiltrado inflamatório e processo de reparo em fase final. Conclusão: 1) através da análise histológica, o processo de ossificação do enxerto autógeno associado ao PRP foi superior; 2) a associação do PRP ao enxerto de banco de ossos humanos demonstrou reparo ósseo superior, quando comparado ao enxerto autógeno utilizado isoladamente.

Objectives: to microscopically evaluate the contribution of Platelet Rich Plasma (PRP) in the process of repairing bone human bones graft stock and autogenous bone in maxillary sinus of dogs. Material and methods: four Beagle dogs, aged 2 years old and about 10 pounds underwent maxillary sinus surgery using autogenous bone graft (right) as a control group and grafting of human bone bank (hand left) associated with the PRP in two dogs, and no other. Samples for analysis were removed with trephine drill within 60 days after grafting. Results: the autograft showed the repair process in development, when combined with PRP showed lamellar organization and the presence of bone marrow. In the allograft was observed disorganized collagen fibrils with loads of osteocytes, and when combined with PRP, it was noted the absence of inflammatory infiltrate, and repair process in the final stage. Conclusion: 1) by histological analysis, the process of ossification of the autogenous PRP was associated with higher; 2) association of PRP to the graft database of human bones showed higher bone healing compared to autograft used alone.

Experimental study on penetration of dental implants into the maxillary sinus in different depths

The exposing of dental implant into the maxillary sinus combined with membrane perforation might increase risks of implant failure and sinus complications. Objective: The purpose of this study was to investigate the effects of the dental implant penetration into the maxillary sinus cavity in different depths on osseointegration and sinus health in a dog model. Material and Methods: Sixteen titanium implants were placed in the bilateral maxillary molar areas of eight adult mongrel dogs, which were randomly divided into four groups according to the different penetrating extents of implants into the sinus cavities (group A: 0 mm; group B: 1 mm; group C: 2 mm; group D: 3 mm). The block biopsies were harvested five months after surgery and evaluated by radiographic observation and histological analysis. Results: No signs of inflammatory reactions were observed in any maxillary sinus of the eight dogs. The tips of the implants with penetrating depth of 1 mm and 2 mm were found to be fully covered with newly formed membrane and partially with new bone. The tips of the implants with penetrating depth over 3 mm were exposed in the sinus cavity and showed no membrane or bone coverage. No significant differences were found among groups regarding implant stability, bone-to-implant contact (BIC) and bone area in the implant threads (BA). Conclusions: Despite the protrusion extents, penetration of dental implant into the maxillary sinus with membrane perforation does not compromise the sinus health and the implant osseointegration in canine. .

Estudo histopatológico comparativo de linfonodos jugulodigástricos em radioterapia de cabeça e pescoço, no cão / Comparative histopathological study of jugulodigastric lymph nodes on head and neck radiotherapy, in the dog

Introdução: A radioterapia pode ser usada com eficácia tantoexclusivamente quanto como adjuvante no tratamento dospacientes com gânglios cervicais clinicamente positivos. Osresultados do tratamento são reservados na maioria dos casos.Objetivo: Descrever as alterações histopatológicas observadasem linfonodos jugulodigástricos de um cão submetido a irradiaçõesde cabeça e pescoço com Cobalto 60 (Co60). Método: Um cãofoi submetido a irradiações da região lateral esquerda da cabeçae pescoço, utilizando-se Cobalto 60 (Co60), com doses semanaisde 2 Gy durante duas semanas, totalizando 4 Gy de radiação.Procedeu-se à exérese de um linfonodo jugulodigástrico esquerdoe de um linfonodo jugulodigástrico direito, com subsequenteanálise histopatológica. Resultados: No linfonodo jugulodigástricodireito foi observada ausência das trabéculas que se projetariamda cápsula e ausência de nódulos linfoides na lâmina, que foitomada por um tecido conjuntivo denso desordenado jovem. Nolinfonodo jugulodigástrico esquerdo observou-se pronunciadafibrose densa ordenada no centro da peça, circundada portecido conjuntivo denso desordenado. Conclusão: Os efeitosda radioterapia atingem também as células constituintes doslinfonodos, ocasionando um processo inflamatório que leva àdestruição dessas células, que são substituídas por tecido fibrosocicatricial. Ocorre então a perda de função dos linfonodos, oque causa obstrução da drenagem linfática e imunossupressãotransitória devido à perda de células do sistema imune.

Bone remodeling at microscrew interface near extraction site in the beagle dog mandible-histologic and immunohistochemical analyses

Extraction is often used as part of orthodontic therapy, and good control of anchorage is a key step after extraction. Although microscrews can be implanted close to the extraction site in order to achieve orthodontic support, the efficiency of bone remodeling at the implant-bone interface near the extraction region is dubious. OBJECTIVE: The purpose of this study was to investigate bone remodeling of the bone-microscrew interface near the tooth extraction site, in the absence of loading. MATERIAL AND METHODS: Third and fourth premolars were extracted from the mandibles of beagle dogs, followed by placement of test microscrews near the extraction sites. Control microscrews were placed further away from the extraction site. All samples were collected after 1, 3, 8, or 12 weeks of healing following extraction. The bone remodeling process at the interface was evaluated using histologic and immunohistochemical analyses. RESULTS: Initially, a large number of inflammatory cells were aggregated at the interface. The expression levels of core binding factor (Cbfa1), osteocalcin (OC) and transforming growth factor beta (TGF-β) were inconspicuous in both groups, whereas tumor necrosis factor alpha (TNF-α) was strongly expressed, especially in the test groups (P<0.05). Subsequently, the expression levels of Cbfa1, OC and TGF-β were found to increase significantly, and active osteogenesis was observed. CONCLUSIONS: During week 1, inflammatory reaction is a major concern at the bone-microscrew interface near the extraction site. However, with healing, the influence of extraction on the remodeling of bone surrounding the microscrews decreases, thus facilitating successful treatment. .