Microbial evaluation of implant surface - a clinical study comparing submerged, non-submerged and immediately loaded implants

Aim: The aim of the present study was to evaluate the microbial contamination in internal and external walls of cone morse implant walls. Methods: Eleven patients with edentulous mandibular posterior area were selected to received dental implants, divided into groups: submerged (S), non-submerged (NS), and immediately loaded (IL). Microbiological evaluations (microorganisms' number, aerobic and anaerobic colony forming units (CFU) number and microorganisms' qualification) were divided into internal and external collection of the implant walls, at different stages: T0 (surgical procedure), T2 (suture removal), T4 (reopening S group), T6 (suture removal S group), and T8 (abutment placement in S and NS). All data were submitted to statistical analyses, with confidence level of 0.05. Results: There was difference in number of microorganisms observed over time within the same group (p < 0.05). A difference was observed in CFU when evaluated within the same group over time (p < 0.05), except for the IL group. In internal collection, a predominance of non-formation of microorganisms was observed at T0 in all groups, while formation of Gram-positive Diplococci and Gram-positive Bacilli was observed at T8 (p>0.05). In external collection, an increase in number of microorganisms was observed at T0. Conclusion: There was no difference in microbial contamination among the evaluated groups. The microorganism's colonization changed over time

Mesenchymal stem cells surpass the capacity of bone marrow aspirate concentrate for periodontal regeneration

Abstract Regenerative approaches using mesenchymal stem cells (MSCs) have been evaluated to promote the complete formation of all missing periodontal tissues, e.g., new cementum, bone, and functional periodontal ligaments. MSCs derived from bone marrow have been applied to bone and periodontal defects in several forms, including bone marrow aspirate concentrate (BMAC) and cultured and isolated bone marrow mesenchymal stem cells (BM-MSCs). This study aimed to evaluate the periodontal regeneration capacity of BMAC and cultured BM-MSCs in the wound healing of fenestration defects in rats. Methodology: BM-MSCs were obtained after bone marrow aspiration of the isogenic iliac crests of rats, followed by cultivation and isolation. Autogenous BMAC was collected and centrifuged immediately before surgery. In 36 rats, fenestration defects were created and treated with suspended BM-MSCs, BMAC or left to spontaneously heal (control) (N=6). Their regenerative potential was assessed by microcomputed tomography (µCT) and histomorphometry, as well as their cell phenotype and functionality by the Luminex assay at 15 and 30 postoperative days. Results: BMAC achieved higher bone volume in 30 days than spontaneous healing (p<0.0001) by enhancing osteoblastic lineage commitment maturation, with higher levels of osteopontin (p=0.0013). Defects filled with cultured BM-MSCs achieved higher mature bone formation in early stages than spontaneous healing and BMAC (p=0.0241 and p=0.0143, respectively). Moreover, significantly more cementum-like tissue formation (p<0.0001) was observed with new insertion of fibers in specimens treated with BM-MSCs within 30 days. Conclusion: Both forms of cell transport, BMAC and BM-MSCs, promoted bone formation. However, early bone formation and maturation were achieved when cultured BM-MSCs were used. Likewise, only cultured BM-MSCs were capable of achieving complete periodontal regeneration with inserted fibers in the new cementum-like tissue.

Knowledge of Dentists and Dental Undergraduates Related to COVID-19

Abstract Objective: To assess the knowledge of Brazilian dentists and final-year dental undergraduates concerning COVID-19. Material and Methods: We conducted a self-administered online questionnaire about the symptoms, incubation period, and transmission routes of COVID-19. In total, there were three questions addressing these topics and 15 correct answers, so each participant could score from 0 to 15 points. Besides that, data such as sex, age, education level, years of work experience and place of work were collected. All data were submitted to statistical analysis with a 5% significance level. Results: 476 participants were recruited. Regarding the respondents' perception of the most common symptoms of COVID-19, 99.4% responded fever, 95.2% cough, and 99.2% dyspnea. About the incubation period, 56.3% answered from 1 to 14 days. About the transmission routes, 98.3% recognized transmission through droplets, 80.3% through direct contact with infected persons, and 70.4% through indirect routes. The median knowledge score was 10 (4 - 14). Regarding the socio-demographic variables, participants aged 30 years or more had a higher score than those aged up to 29 years old (p=0.004). For education level, specialist dentists presented a higher score than undergraduates (p=0.006), general dentists (p=0.048) and Ph.D. (p=0.016). Participants with 15 years or more of work experience had a higher score than undergraduates (p=0.003). Concerning the workplace, participants working in the public sector had a higher score than those working in the private sector or universities (p=0.015). Conclusion: Participants recognized the main symptoms, incubation period, and transmission routes of the COVID-19 virus; however, the knowledge level of specialist dentists, older dentists, more experienced dentists, and dentists working in the public sector was higher than the other participants (AU).

The influence of early bisphosphonate treatment in bone reconstruction on craniofacial radiographic bone density / A influência do tratamento com bisfosfonatos na densidade óssea em área de reconstrução óssea craniofacial

Objective: To evaluate the effects of alendronate (AL), a bisphosphonate, on visual bone density by means of a radiographic analysis. Material and methods: Sixty-two Wistar rats were divided into four groups: Group AA (AL with autogenous graft); group AW (AL without autogenous graft) both receiving AL on alternate days for 4 weeks before surgery; control group CA (with autogenous graft); group CW (without autogenous graft) both receiving saline solution before surgery. Experimental periods of evaluation were 2 weeks and 4 weeks postsurgery. Conventional and digital radiographs were obtained, and a 5-point grading system (score) was used to assess visual radiographic bone density. Results: There were no statistical differences between CA and AA groups at 2 and 4 weeks. The AA group had a higher mean score of bone density than the CW and AW groups at 2 weeks (P < 0.05). The CA and AA groups had higher scores of bone density than the CW and AW groups at 4 weeks (P < 0.05). Conclusions: Treatment with AL did not affect radiographic bone density at 2 and 4 weeks after surgery. The presence of an autograft resulted in higher scores of bone density. (AU)

Objetivo: Avaliar os efeitos do alendronato (AL), um bisfosfonato, na densidade óssea através de uma análise radiográfica. Material e métodos: Sessenta e dois ratos Wistar foram divididos em quatro grupos: Grupo AA (AL com enxerto ósseo autógeno); grupo AW (AL sem enxerto ósseo autógeno); ambos receberam AL em dias alternados durante 4 semanas antes da cirurgia; grupo controle CA (com enxerto ósseo autógeno); grupo CW (sem enxerto ósseo autógeno) ambos receberam solução salina antes da cirurgia. Os tempos experimentais de avaliação foram 2 e 4 semanas após a cirurgia. Radiografias convencionais e digitais foram realizadas, e um sistema de escore de 5 pontos foi utilizado para avaliar a densidade óssea radiográfica visualmente. Resultados: Não houve diferença estatisticamente significativa entre os grupos CA e AA em 2 e 4 semanas. O grupo AA apresentou maior escore de densidade óssea do que os grupos CW e AW em 2 semanas (p < 0.05). Os grupos CA e AA apresentaram maior escore de densidade óssea do que os grupos AW e CW em 4 semanas (p < 0.05). Conclusões: O tratamento com AL não interferiu na densidade óssea radiográfica em 2 e 4 semanas após cirurgia. A presença do enxerto resultou em maior escore de densidade óssea. (AU)

Does the implant-abutment interface interfere on marginal bone loss? A systematic review and meta-analysis

Abstract The objective of this systematic review was to compare the conical internal connection (IC) with the external hexagonal connection (EH) on the occurrence of marginal bone loss (ΔMBL). Different databases were used to carry out the selection of the elected studies. The studies were judged according to the risk of bias as "high", "low" and "unclear" risk. For the meta-analysis we included only studies that could extract the data of ΔMBL, survival rate (SR) and probing depth (PD). No statistically significant differences were found for ΔMBL data at one, three- and five-year survival rates between implant connections (p <0.05), however statistically significant differences were found for PD between EH and IC implants (1-year follow-up) -0.53 [95%CI -0.82 to -0.24, p = 0.0004]. This present systematic review demonstrated that there are no significant differences between IC and EH implants for both ΔMBL and SR at 1, 3 e 5 years after functional loading, although better PD values were observed for implants pertaining to the IC connections. Considering the high heterogeneity, more well-delineated, randomized clinical trials should be conducted.

Effect of local application of alendronate and parathyroid hormone on craniofacial bone repair - a preliminary study

Abstract This study aimed to evaluate the effect of two methods of local application of alendronate and parathyroid hormone (PTH) on bone repair and the systemic implications. A critically sized defect (5 mm) was created in the cranial region of twenty-five male Wistar rats, and the bone removed was particulated, and grafted back to the defect with different treatments. The animals were randomly divided into five groups: A1- bone graft immersion in alendronate solution (3 mg/kg) for 5 minutes; P1- bone graft immersion in PTH solution (20 µg); A2- weekly local applications of alendronate 1 mg/kg; P2- weekly local applications of PTH (20 µg); C- no drugs were used. The animals were euthanized 60 days after surgery. Cranial bone blocks were removed for histological, histomorphometric, and immunohistochemical analyses. MMP-2 and MMP-9 were used for immunolabeling. The kidneys, liver, and brain were also removed from all the rats for histological analysis. The data were submitted for statistical analysis with a level of significance of 0.05 (One-way ANOVA). The group C and group P2 presented a higher quantity of viable bone particles than the remaining groups. Groups A1, A2, and P1 presented with fewer viable bone particles than the control group, with a predominance of non-mineralized connective tissue. The histomorphometric analysis revealed no differences in relative bone area or MMP-2 or MMP-9 immunolabeling between the groups (p>0.05). Group A2 showed presence of fat in the liver consistent with hepatic steatosis. Changes in brain tissue were observed in groups A1 and P1.

Resumo Este estudo visou avaliar o efeito de dois métodos de aplicação local de alendronato e de paratormônio (PTH) no reparo ósseo e avaliar as implicações sistêmicas. Um defeito de tamanho crítico (5 mm) foi criado na calota craniana de vinte e cinco ratos Wistar machos, e o osso removido foi particulado e enxertado de volta no defeito com diferentes tratamentos. Os animais foram divididos aleatoriamente em cinco grupos: A1: imersão do enxerto ósseo em solução de alendronato (3 mg/kg) durante 5 min; P1- imersão do osso em solução de PTH (20 μg); A2- aplicações locais semanais de alendronato 1 mg/kg; P2- aplicações locais semanais de PTH 20 μg; C: não foram utilizados medicamentos. Os animais foram eutanasiados 60 dias após a cirurgia. Foram removidos os blocos ósseos envolvendo a região do defeito para realização das análises histológica, histomorfométrica e imuno-histoquímica. MMP2 e MMP9 foram as imunomarcações utilizadas. Os rins, fígado e cérebro também foram removidos de todos os ratos para análise histológica. Os dados foram submetidos à análise estatística com um nível de significância de 0,05 (One-way ANOVA). A análise histológica revelou que o grupo C e o grupo P2 apresentaram maior quantidade de partículas ósseas viáveis do que as apresentadas pelos demais grupos. Os grupos A1, A2 e P1 apresentaram menos partículas ósseas viáveis em comparação com o grupo controle com predominância de tecido conjuntivo não mineralizado. A análise histomorfométrica não revelou diferenças entres os grupos na área óssea relativa ou em MMP2 e MMP9 (p>0,05). O grupo A2 mostrou presença de gordura no fígado consistente com esteatose hepática. Alterações no tecido cerebral foram observadas nos grupos A1 e P1.

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.

Platelet Rich Plasma (PRP) Produces an Atherofibrotic Histophenotype During Craniofacial Bone Repair Due to Changes of Immunohistochemical Expression of Erk1/2, p38α /β, Adiponectin and Elevated Presence of Cells Exhibiting B-scavenger Receptor (CD36+)

Abstract The platelet-extracellular matrix interaction in platelet rich plasma (PRP) through thrombospondin receptor-CD36 induces the secretion of growth factors responsible for cellular proliferation and differentiation during the repair process. Since CD36 also acts as a class B-scavenger-receptor for development of foam-like cells and mitogen-activated kinases, such as Erk1/2 and p38α/β, are important proteins activated by platelet growth factor, the aim of this study was to evaluate the immunohistochemical presence of CD36, Erk1/2, p38α/β during the bone repair treated and non-treated with PRP and to compare these results with the histomorphometry of repair. Simultaneously, the immunopresence of adiponectin was analyzed, which may contribute to osteogenesis at the same time it inhibits fibrosis and impairs adipogenesis and foam cell formation in the medullary area. An artificial bone defect measuring 5×1 mm was produced in the calvaria of 56 Wistar rats. The defects were randomly treated with autograft, autograft+PRP, PRP alone and sham. The animals were euthanized at 2 and 6 weeks post-surgery. Data were analyzed by ANOVA followed by non-parametric test Student Newman-Keuls (p<0.05) for histomorphometric and immunohistochemical interpretation. The results revealed that in specimens that received PRP the immunopositivity for Erk1/2, p38α/β and CD36 proteins increased significantly while the immunohistochemical expression of adiponectin decreased simultaneously. There was also an accentuated reduction of bone matrix deposition and increase of the medullary area represented by fibrosis and/or presence of foam-like cells, which exhibited immunophenotype CD36+adiponectin. The findings of this study suggest that PRP acted as an inhibitor of osteogenesis during the craniofacial bone repair and induced a pathological condition that mimics an atherofibrotic condition.

Resumo A interação da matriz extracelular-plaquetas no plasma rico em plaquetas (PRP) através de receptor trombospondina CD36 induz a secreção de fatores de crescimento responsáveis pela proliferação e diferenciação celular durante o processo de reparo. Uma vez que o CD36 também age como receptor scavenger de classe B para o desenvolvimento de células do tipo espuma, e as quinases ativadas por mitógenos, tais como ERK1/2 e p38α/β, são importantes proteínas ativadas por fator de crescimento das plaquetas, o objetivo deste estudo foi avaliar a presença imunoistoquímica de CD36, ERK1/2, p38α/β durante o reparo ósseo tratado e não-tratado com PRP e comparar estes resultados com a histomorfometria do reparo. Simultaneamente, analisou-se a imunopresença da adiponectina, que pode contribuir para osteogênese ao mesmo tempo que inibe a fibrose e prejudica a formação de células tipo espuma/xantomatosas na área medular. Um defeito artificial de osso medindo 5×1 mm foi produzido na calvária de 56 ratos Wistar. Os defeitos foram tratados aleatoriamente com auto-enxerto, enxerto autógeno+PRP, PRP apenas e sham. Os animais foram sacrificados 2 e 6 semanas pós-cirurgia. Os dados foram examinados por meio de ANOVA, seguido pelo teste não-paramétrico Student Newman-Keuls (p<0,05) para a interpretação histomorfométrica e imunoistoquímica. Os resultados revelaram que as amostras que receberam PRP aumentaram significativamente a imunopositividade para as proteínas ERK1/2, p38α/β e CD36, simultaneamente à diminuição de expressão imunoistoquímica da adiponectina. Houve também expressiva redução de deposição de matriz óssea e aumento da área medular representada por fibrose e/ou presença de células do tipo espuma que apresentaram imunofenótipo CD36 + adiponectina. Estes resultados sugerem que o PRP atuou como um inibidor da osteogênese durante o reparo ósseo craniofacial e induziu uma condição patológica que mimetiza uma condição aterofibrótica.

Recontorno gengival e reposicionamento labial cirúrgico para tratamento do sorriso gengival: resultados após um ano / Gummy smile treatment with gingival recontouring and surgical lip repositioning: 1-year follow-up results

O presente artigo teve como objetivo esclarecer as diferentes alternativas utilizadas para o reposicionamento labial e melhora da estética do sorriso, propondo uma nova classificação para o diagnóstico e tratamento do sorriso gengival. A técnica cirúrgica descrita no relato de caso associa o recontorno gengival e o reposicionamento labial com tratamento estético restaurador. A cirurgia realizada proporcionou a correção da erupção passiva alterada dos dentes anterossuperiores, combinada com o alongamento do feixe lateral do músculo levantador do lábio superior e da asa do nariz, e a contenção do mesmo com sutura mononylon, diminuindo o sorriso gengival. Notou-se, após a cirurgia, que a linha alta do sorriso foi corrigida sem comprometer a harmonia labial. A paciente manifestou alto grau de satisfação com o tratamento. O diagnóstico e a técnica cirúrgica proposta neste estudo podem ser uma opção terapêutica para o reposicionamento labial e harmonia do sorriso.

The present article aims to address the different alternatives used for lip repositioning and improved smile aesthetics, proposing a new classification for the diagnosis and treatment of the gummy smile. The surgical technique described this a case report associates gingival recontouring and lip repositioning with restorative aesthetic treatment. The surgery provided the correction of altered passive eruption of the anterior superior teeth combined with lengthening of the lateral bundle levator muscle of the upper lip and the ala of the nose, containing them with mononylon sutures, decreasing the gummy smile. It was noted that after surgery, the high smile line was corrected without compromising the labial harmony. The patient expressed high satisfaction with the treatment. The diagnosis and surgical technique proposed in the present study may be a therapeutic option for lip repositioning and smile harmony.

Effect of the use of different periodontal curettes on the topography and roughness of root surface

Introduction: Periodontal scaling is the treatment approach most used to remove dental calculus, plaque, and altered cementum from root surface. During root decontamination, the instruments used leave the root rougher and more irregular. Objective: To verify the root surface after mechanical scaling with different Gracey curettes steel through SEM and superficial roughness analyses. Material and methods: Twelve teeth were embedded in acrylic resin. The teeth were instrumented with new Gracey curettes Gracey 5/6 from different brands. The groups (n=2) were divided into: control, no instrumentation (GC); carbon steel (CSN); stainless steel Neumar (SSN); stainless steel Millenium (SSM); premium steel Neumar (PSN); Hu-Friedy (HF). An area measuring 3 x 3 mm2 was marked on the distal surface of the root to guide the Reading of the root topography on SEM and rugosimeter. The data were analyzed by a single examiner previously calibrated. SEM analysis was based on scores of the root surface smoothness after scaling. We analyzed the parameters of mean roughness (Ra) and mean roughness deepness (Rz). SEM data were submitted to statistical analysis through Fisher's exact test (p < 0.002) and roughness data by Anova followed by Student t test. Results: The quality of the active surface of the curette demonstrated by SEM and roughness analyses that it can exert difference in the result regarding to the homogeneity produced after the scaling of root surface. Group SSM demonstrated a homogenous root surface (score 0) in SEM and better smoothness in rugosimeter analysis. Conclusion: According to com the methodology used, the group of curettes that provided better smoothness of root surface after scaling was SSM.

Evaluating surfaces of titanium dental implants after contact with surgical gloves, steel rongeur, and titanium tweezers using scanning electron microscopy

Introduction and Objective: To use scanning electron microscopy (SEM) and determine whether the surfaces of titanium implants are damaged when touched with a steel rongeur, titanium tweezers, or surgical gloves. Material and methods: Ten dental implants were divided into five groups: Control (C), Titanium Tweezers (T-T), Steel Rongeurs (S-R), Surgical Gloves (S-G), and Steel Support (S-S). The implants were assembled in a metallic base (stub) with the aid of copper strips. They were then imaged and their microstructures were characterized using SEM. Results: An analysis of the obtained images showed that the implants that had been handled with titanium tweezers or a steel rongeur suffered some damage to their physical structure; "scratches" and other small signs of damage were visible on their surfaces. The affected areas were very small compared to the total surface area of the implants. Small dark local stains were observed at the spots where some of the implants had rubbed against a steel support. The rubbing of the implants against the support did not cause any structural damage. The implants handled with surgical gloves exhibited many dark stains their surfaces. This suggested that the powder from the surgical gloves had contaminated the surfaces of the implants. Conclusion: Using SEM imaging, it was determined that the surfaces of dental implants suffer minor physical damage when handled with various pieces of dental equipment. However, the damage should not result in failure of the osseointegration process. In vivo studies are needed to confirm this hypothesis.

Investigation of the influence of design details on short implant biomechanics using colorimetric photoelastic analysis: a pilot study

Introduction : The clinical survival of a dental implant is directly related to its biomechanical behavior. Since short implants present lower bone/implant contact area, their design may be more critical to stress distribution to surrounding tissues. Photoelastic analysis is a biomechanical method that uses either simple qualitative results or complex calculations for the acquisition of quantitative data. In order to simplify data acquisition, we performed a pilot study to demonstrate the investigation of biomechanics via correlation of the findings of colorimetric photoelastic analysis (stress transition areas; STAs) of design details between two types of short dental implants under axial loads. Methods Implants were embedded in a soft photoelastic resin and axially loaded with 10 and 20 N of force. Implant design features were correlated with the STAs (mm2) of the colored fringes of colorimetric photoelastic analysis. Results Under a 10 N load, the surface area of the implants was directly related to STA, whereas under a 20 N load, the surface area and thread height were inversely related to STA. Conclusion A smaller external thread height seemed to improve the biomechanical performance of the short implants investigated.

Non-Pedicled Buccal Fat Pad Grafts to Treatment for Class I and II Gingival Recessions: A Clinical Trial

The aim of this study was to analyze the transplant efficiency of non-pedicled buccal fat pad graft (BFPG) for the treatment of Miller Class I or II gingival recessions (GRs) and to compare these results with those of subepithelial connective tissue graft (SCTG), which is considered the gold standard. Twelve patients with Miller Class I or II (≥2 mm) bilateral recessions in maxillary premolars or canines were selected. Recessions were randomly assigned to receive SCTG or BFPG. The clinical parameters evaluated at baseline and at 1, 3, and 6 months postoperatively included gingival index, plaque index, probing depth, GR, clinical attachment level, width of keratinized tissue, thickness of keratinized tissue and gingival margin to the acrylic guide. None of the evaluated clinical parameters differed significantly between the groups. At all evaluated postoperative time-points, both groups exhibited statistically significant differences in GR and gingival margin to the acrylic guide compared to baseline. Six months after surgery, the mean percentages of root coverage were 67.5% and 87.5% in the BFPG and SCTG groups respectively. In both groups, complete root coverage was observed in 50% of cases 6 months after surgery. The results presented herein indicate that the use of BFPG transplant has clinical similarities with SCTG and both may be considered as clinically successful methods for treating Miller Class I and II GRs.

Resumo O objetivo deste estudo foi analisar a eficiência do transplante do enxerto de tecido adiposo bucal não pediculado (ETAB) para o tratamento de recessões gengivais Classe I e II de Miller e comparar seus resultados com o enxerto de tecido conjuntivo (ETC), que é considerado o enxerto padrão ouro. Foram selecionados 12 pacientes com recessões gengivais bilaterais Classe I e II de Miller presentes em canino ou pré-molares maxilares. As recessões foram randomizadas para receber um dos dois tratamentos ETAB ou ETC. Os parâmetros clínicos avaliados no baseline e com 1, 3 e 6 meses de pós-operatório foram o índice gengival, índice de placa, profundidade de sondagem, recessão gengival (RG), nível clinico de inserção, espessura e largura de tecido queratinizado e a medida da margem gengival ao guia de acrílico (MG-GA). Os resultados mostraram que não houve diferença estatisticamente significativa entre os grupos em nenhum dos parâmetros clínicos avaliados. Os parâmetros clínicos de RG e MG-GA, em ambos os grupos, apresentaram diferença estatisticamente significativa nos 3 períodos pós-operatórios em relação ao baseline. Aos 6 meses de pós-operatório, a média percentual de recobrimento radicular foi de 67,5% e 87,5% para o grupo ETAB e ETC respectivamente. Em ambos os grupos o recobrimento radicular completo foi em 50% dos casos após 6 meses de pós-operatório. Pode-se concluir que o transplante do ETAB apresentou similaridades clínicas com o ETC e ambos os tratamentos podem ser considerados de sucesso clínico para o tratamento de RGs Classe I e II de Miller.

Influence of bisphosphonates on Implantology - literature review

Introduction: Oral rehabilitation with dental implants becomes limited in patients who make use of sodium bisphosphonate (BF), because this drug inhibits osteoclast activity and thus osteoblastic, fundamental steps to implant osseointegration. Furthermore, this drug can cause osteonecrosis of the jaw (OJ). The dentist has to fully know about this drug and its side effects, to differentiate it from other changes. Objective: This study aimed to review the literature on the influence of bisphosphonates on implant and to evaluate the possible complications resulting from prolonged use, providing subsidies to the dentist to prevent and recognize the patient with osteonecrosis of the jaws Literature review: The BPs are a class of drugs used for the treatment of bone diseases such as osteoporosis, because their mechanism of action inhibits the function of osteoclast. However, these drugs may cause some side effects known as the OJ. Patients undergoing intravenous therapy are more likely to develop these changes than those undergoing oral therapy. OJ is characterized by painful symptoms, leaving the exposed bone in the oral cavity. There are several treatment strategies according to the clinical stage that the patient presents. Conclusion: The installation of dental implants in patients who make use of BPs presents risks, since this drug can cause OJ.

Platelet-leukocyte-rich plasma (L-PRP) prevents the collagen III degradation and impairs the bone matrix development in artificial defect of rabbit calvaria, associated with suppression of the immunohistochemical expression of MMP-2 and MMP-9

Introduction and Objective: Because L-PRP constitutes an important source of growth factor that is associated with osteogenesis and fibrogenesis, the aim of this study was to evaluate the effect of L-PRP on the presence of collagen III and MMP-2 and MMP-9, while comparing these results by means of a histomorphometric analysis of bone matrix and fibrous deposition on bone repair. Material and methods: Four bone defects of 8 × 2 mm were created on the calvaria of 21 rabbits. The surgical defects were treated with either particulate autograft, particulate autograft mixed with L-PRP, or L-PRP alone. Animals were euthanized at 2, 4, and 6 weeks postoperative. Histomorphometric and immunohistochemical analyses were performed to assess repair time, as well as the expression of collagen III and MMPs. Results: In contrast to the results of the L-PRP-free groups, the histomorphometric results of the L-PRP groups demonstrated intense fibrotic deposition along with hindered bone matrix deposition. These results coincided with the larger occurrence of diffuse collagen III deposition and the scarce presence of MMP- 2 and -9 spread among the fibrous tissue. Conclusion: Thus, the results suggest that L-PRP not only induces an intense fibrosis rich in collagen III, which is not degraded, but also suppresses MMP-2 and -9 expressions, mimicking a similar pathological event as that of a cleft-palate or cranial suture.

Uso da cola cianoacrílica para estabilização de enxerto gengival livre / Cyanoacrylate surgical glue for free gingival graft immobilization

Introdução: a recessão gengival é definida como a mi-gração apical da margem da gengiva tendo como conse-quências a exposição radicular e a redução da faixa de gengiva inserida. O enxerto gengival livre (EGL) é uma opção de tratamento para esses casos. A estabilização do enxerto na área receptora pode influenciar o resul-tado final do procedimento. Objetivo: o presente relato de caso tem como objetivo demonstrar que o EGL pode ser fixado na região cirúrgica com o uso da cola cirúr-gica N-butyl 2-cyanoacrylate (Glubran-2), substituindo as suturas convencionais, no tratamento de regiões des-providas de gengiva inserida. Relato de caso: a investi-gação, neste estudo, se deu em uma paciente do sexo feminino de 22 anos com recessão gengival classe I de Miller no dente 41 com um defeito de 5 mm na vestibu-lar, bem como ausência de gengiva inserida. O EGL foi posicionado sobre a linha mucogengival formando um leito receptor e uma gota da cola Glubran-2 foi coloca-da em cada extremidade do enxerto para estabilização. Considerações finais: com base nos dados observados, conclui-se que a cola cirúrgica N-butyl 2-cyanoacrylate (Glubran-2) pode ser considerada como substituta ao uso de suturas convencionais.

Immunoexpression of PPAR-? and Osteocalcin Proteins for Bone Repair of Critical-Size Defects Treated with Fragmented Autogenous Abdominal Adipose Tissue Graft

Immunoexpression of PPAR-γ and osteocalcin proteins was evaluated for bone repair of critical-size defects (CSDs), created in rat calvaria (n=42) and treated with fragmented abdominal autogenous adipose tissue graft. Three groups (n=14) were formed: C (control - blood clot), AB (autogenous bone) and AT (fragmented adipose tissue). The groups were divided into subgroups (n=7) for euthanasia at 30 and 90 days. Histological and immunohistochemical analyses were performed. Data were subjected to descriptive statistics (mode). A complete bone closure was observed in Group AB 90 days after surgery. In Group C, repair was achieved by the formation of collagen fiber bundles oriented parallel to the wound surface at both post-surgery periods. In Group AT the type of healing was characterized by dense connective tissue containing collagen fiber bundles arranged amidst the remaining adipose tissue, with rare heterotopic bone formation associated with fibrosis and different types of tissue necrosis. Immunostaining of PPAR-γ was not observed in any specimen from Groups C and AB. In Group AT, the immunostaining of PPAR-γ was more evident 30 days after surgery. Immunostaining of osteocalcin was present in all groups and at both postoperative periods. The fragmented autogenous abdominal adipose tissue graft did not favor the repair of critical-size bone defects created surgically in rat calvaria as evidenced by the positive immunostaining of PPAR-γ protein and the negative immunostaining of osteocalcin in the osteoblast-like cells and bone matrix.

A imunoexpressão das proteínas PPAR-γ e osteocalcina foi avaliada para o reparo ósseo de defeitos de tamanho crítico (DTC) criados em calvária de ratos (n = 42) e tratados com enxerto de tecido adiposo autógeno abdominal macerado. Foram formados três grupos (n=14): C (controlo - coágulo de sangue), AB (osso autógeno) e AT (tecido adiposo fragmentado). Estes grupos foram divididos em subgrupos (n = 7) para a eutanásia em 30 e 90 dias. Foram realizadas análises histológicas e imuno-histoquímico. Os dados foram submetidos à análise estatística descritiva (moda). Um fechamento ósseo completo foi observada no grupo AB 90 dias após a cirurgia. No grupo C a reparação foi alcançada através da formação de feixes de fibras de colágeno orientadas paralelamente à superfície da ferida nos dois períodos pós-operatórios. No Grupo AT, o tipo de cicatrização predominante foi caracterizada pela presença de tecido conjuntivo denso contendo feixes de colágeno de fibras dispostas em meio ao tecido adiposo restante, com raras formações ósseas heterotópicas associada à fibrose e diferentes tipos de necrose tecidual. A imunomarcação do PPAR- γ não foi observada em nenhum espécime dos grupos C e AB. No grupo AT a imunomarcação do PPAR-γ foi mais evidente aos 30 dias de pós-operátorio. A imunomarcação da osteocalcina estava presente em todos os grupos e nos dois períodos de pós-operatório O enxerto autógeno abdominal fragmentado tecido adiposo não favoreceu a reparação de defeitos ósseos de tamanho crítico criados cirurgicamente em calvária de ratos como evidenciado pela imunomarcação positiva da proteína PPAR-γ e a imunomarcação negativa de osteocalcina nos osteoblastos e matriz óssea.

Immunoexpression of BMP-2 protein on bone repair of critical size defects treated with autogenous macerated adipose tissue

Introduction: The adipose tissue is an important reservoir of adult stem cells which have capacity of differentiating in osteoblasts with potential implication in reaching bone regeneration. The evaluation of the osteoblastic differentiation can be verified through immunohistochemical markers such as bone morphogenetic protein- 2 (BMP-2). Objective: To evaluate the immunoexpression of BMP-2 protein on the bone repairing of critical size defects (CSD) surgically created in rat calvaria and treated by autogenous macerated adipose tissue. Material and methods: Forty male rats had a CSD measuring 5 mm created on their calvaria. The animals were randomly divided into two groups: group C (control) and group AT (macerated adipose tissue grafting). In group C, the defect was filled with only blood clot. In group AT, the defect was filled with autogenous macerated adipose tissue. The groups were subdivided into two subgroups (n = 10) for euthanasia at 7 and 90 post-operative days. Histological and immunohistochemical analyses were carried out. Data were submitted to descriptive statistics (mode). Results: In group AT, both at 7 and 90 post-operative days, the main healing type was the presence of dense conjunctive tissue exhibiting bundles of collagen fibers disposed in beams permeating the remaining adipose tissue with rare heterotopic bone formation associated to fibrosis and different types of tissue necrosis. In group C, the repair was achieved by the formation of bundles of collagen fibers oriented parallelly to the surface of the wound at the two post-surgical periods. The immune-staining of BMP-2 was present only in group C (7 and 90 post-operative days). Conclusion: Within the limits of this present study, it can be concluded that the adipose tissue grafting did not favor bone neoformation in critical size defects and BMP-2 signaling was not observed.

Reconstrução de maxila atrófica com uso de enxerto ósseo homólogo particulado com macro e micropartículas antes da colocação de implantes dentários / Reconstruction of the atrophic maxillary arch with homologous macro and microparticulate homologous bone grafts before dental implant placement: a case report

Este relato de caso descreve uma nova técnica de reconstrução para o rebordo maxilar atrófico antes da colocação de implantes dentários. Enxertos homólogos consistindo de macro e micropartículas foram injetados sem o uso de membranas. Após 11 meses, o tecido gengival demonstrou aspecto saudável e ganho em espessura no rebordo alveolar. Os exames por imagem também demonstraram ganho em altura. Esta técnica é uma alternativa clínica viável e menos traumática em relação às outras técnicas para o aumento ósseo em maxilas atróficas

This case report describes a new technique to reconstruct the atrophic maxillary arch before dental implant placement. Macro and microparticulate homologous grafts were injected without membrane insertion. After 11 months, the gingival tissue displayed normal condition along with improved alveolar bone thickness. Also, the CBCT images demonstrated benefits in bone height. This is a viable clinical alternative and less traumatic than other surgical modalities for bone grafting in the atrophic maxilla.