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

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 (⍺=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 versusmicroscopy). 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

Periapical bone response to bacterial lipopolysaccharide is shifted upon cyclooxygenase blockage

Objectives: Infection, inflammation and bone resorption are closely related events in apical periodontitis development. Therefore, we sought to investigate the role of cyclooxygenase (COX) in osteoclastogenesis and bone metabolism signaling in periapical bone tissue after bacterial lipopolysaccharide (LPS) inoculation into root canals. Methodology: Seventy two C57BL/6 mice had the root canals of the first molars inoculated with a solution containing LPS from E. coli (1.0 mg/mL) and received selective (celecoxib) or non-selective (indomethacin) COX-2 inhibitor. After 7, 14, 21 and 28 days the animals were euthanized and the tissues removed for total RNA extraction. Evaluation of gene expression was performed by qRT-PCR. Statistical analysis was performed using analysis of variance (ANOVA) followed by post-tests (α=0.05). Results: LPS induced expression of mRNA for COX-2 (Ptgs2) and PGE2 receptors (Ptger1, Ptger3 and Ptger4), indicating that cyclooxygenase is involved in periapical response to LPS. A signaling that favours bone resorption was observed because Tnfsf11 (RANKL), Vegfa, Ctsk, Mmp9, Cd36, Icam, Vcam1, Nfkb1 and Sox9 were upregulated in response to LPS. Indomethacin and celecoxib differentially modulated expression of osteoclastogenic and other bone metabolism genes: celecoxib downregulated Igf1r, Ctsk, Mmp9, Cd36, Icam1, Nfkb1, Smad3, Sox9, Csf3, Vcam1 and Itga3 whereas indomethacin inhibited Tgfbr1, Igf1r, Ctsk, Mmp9, Sox9, Cd36 and Icam1. Conclusions: We demonstrated that gene expression for COX-2 and PGE2 receptors was upregulated after LPS inoculation into the root canals. Additionally, early administration of indomethacin and celecoxib (NSAIDs) inhibited osteoclastogenic signaling. The relevance of the cyclooxygenase pathway in apical periodontitis was shown by a wide modulation in the expression of genes involved in both bone catabolism and anabolism

Root canal contamination or exposure to lipopolysaccharide differentially modulate prostaglandin E2 and leukotriene B4 signaling in apical periodontitis

Purpose: To evaluate the kinetics of apical periodontitis development in vivo , induced either by contamination of the root canals by microorganisms from the oral cavity or by inoculation of bacterial lipopolysaccharide (LPS) and the regulation of major enzymes and receptors involved in the arachidonic acid metabolism. Methodology: Apical periodontitis was induced in C57BL6 mice (n=96), by root canal exposure to oral cavity (n=48 teeth) or inoculation of LPS (10 µL of a suspension of 0.1 µg/µL) from E. coli into the root canals (n= 48 teeth). Healthy teeth were used as control (n=48 teeth). After 7, 14, 21 and 28 days the animals were euthanized and tissues removed for histopathological and qRT-PCR analyses. Histological analysis data were analyzed using two-way ANOVA followed by Sidak’s test, and qRT-PCR data using two-way ANOVA followed by Tukey’s test (α=0.05). Results: Contamination by microorganisms led to the development of apical periodontitis, characterized by the recruitment of inflammatory cells and bone tissue resorption, whereas inoculation of LPS induced inflammatory cells recruitment without bone resorption. Both stimuli induced mRNA expression for cyclooxygenase-2 and 5-lipoxygenase enzymes. Expression of prostaglandin E2 and leukotriene B4 cell surface receptors were more stimulated by LPS. Regarding nuclear peroxisome proliferator-activated receptors (PPAR), oral contamination induced the synthesis of mRNA for PPARδ, differently from inoculation of LPS, that induced PPARα and PPARγ expression. Conclusions: Contamination of the root canals by microorganisms from oral cavity induced the development of apical periodontitis differently than by inoculation with LPS, characterized by less bone loss than the first model. Regardless of the model used, it was found a local increase in the synthesis of mRNA for the enzymes 5-lipoxygenase and cyclooxygenase-2 of the arachidonic acid metabolism, as well as in the surface and nuclear receptors for the lipid mediators prostaglandin E2 and leukotriene B4

Case Report: Applicability of sedation with nitrous oxide in the management of molar incisor hypomineralization in pediatric patients

Patients with molar-incisor hypomineralization (MIH) may manifest tooth hfypersensitivity and difficulties in undergoing dental treatment, including fear, anxiety, and behavior problems in the dental office. Then, the objective of this study was to report a clinical case series using inhalation sedation with nitrous oxide and oxygen as a clinical strategy in the management of MIH pediatric patients during dental treatment. Pediatric patients and their legal guardians were properly informed and data were extracted from clinical charts. Six clinical cases were included, whose patients were between 8 and 12 years old. Of these, 4 were female. The indication of moderate sedation took into account the clinical difficulties related to patients with MIH, such as obtaining anesthesia and cooperation, in addition to odontophobia and dental anxiety. All patients were carefully examined to undergo the sedation technique, including medical history and previous experiences with nitrous oxide inhalation sedation, as well as the vital signs were properly evaluated before, during and after the procedures. The nitrous oxide concentration ranged between 30% and 60%. The procedures were restorative, endodontic or surgical (extractions). In general, the use of sedation contributed to the performance of dental procedures. The use of inhaled sedation helped in behavioral management and during the treatment, increasing the effectiveness of local anesthesia. Patients were cooperative for treatment, while no adverse effects or complications related to sedation were observed. Thus, for the patients in this case series, the use of inhalation sedation with nitrous oxide and oxygen contributed to the clinical management of patients with MIH

Fratura coronorradicular na dentição decídua com tratamento tardio: relato de caso clínico

As lesões dentárias traumáticas são uma urgência odontológica comum, sendo a fratura coronorradicular considerada relativamente rara, representando 2,5% dos casos de traumatismos dentários. Na dentição decídua, a prevalência do traumatismo dental é de 22,7%. O presente caso clínico relata o caso de uma criança de três anos de idade que compareceu à Clínica de Odontopediatria com fratura coronorradicular no dente 61 ausente de tratamento por dois anos. Clinicamente, observa-se a falta da coroa do dente 61 e a presença de um pólipo pulpar com coágulo sanguíneo em sua superfície. O exame radiográfico foi realizado apenas dois anos após o primeiro trauma, foi constatada a presença de reabsorção radicular extensa, não fisiológica e a impossibilidade de reabilitação estético-funcional fixa, indicando a necessidade de extração do fragmento radicular. Realizou-se a extração do fragmento e acompanhamento após a intervenção. Apesar da paciente apresentar inexistência de alterações clínicas no dente permanente, o trauma dentário deve ser diagnosticado e tratado de forma imediata, pois sabe-se que um bom prognóstico está diretamente relacionado com o tempo entre a ocorrência do trauma e a intervenção odontológica

Matrix metalloproteinases: role in the development of apical periodontitis and modulation after endodontic treatment

Introdução: A lesão periapical representa a resposta imunoinflamatória devido ao aumento do número e progressão de micro-organismos advindos dos canais radiculares contaminados em direção aos tecidos apicais e periapicais, resultando em reabsorção óssea. O objetivo desta revisão será abordar a importância das metaloproteinases da matriz no desenvolvimento das lesões periapicais e sua modulação durante a fase de reparação tecidual depois de instituído o tratamento endodôntico. Revisão da literatura: A patogênese da lesão periapical envolve a degradação progressiva de diversos componentes da matriz extracelular. Dentre as proteases responsáveis pela degradação destes componentes estão as metaloproteinases da matriz (MMPs). Estas proteinases são expressas em resposta a estímulos específicos pelas células residentes do tecido conjuntivo durante o processo de remodelação tecidual e por células inflamatórias que invadem os tecidos durante eventos inflamatórios. As MMPs foram descritas em lesões periapicais experimentais e em humanos e existem evidências de que estas enzimas apresentam padrões de expressões diferentes em granulomas e cistos periapicais. A terapia endodôntica é importante para a redução da inflamação periapical assim como da síntese das MMPs, principalmente quando utilizado um curativo de demora à base de hidróxido de cálcio. Conclusão: As lesões periapicais apresentam alta expressão de metaloproteinases da matriz e o tratamento endodôntico em dentes com lesão periapical resulta em menor expressão de MMPs quando comparado às lesões periapicais não tratadas.Introduction: Apical periodontitis represents a local immune response directed against the progression of microorganisms from the dental pulp to the apical foramen and periapical tissues, which results in bone and dental resorption. The aim of this review is to describe the expression of this group of proteases in apical periodontitis and its modulation during the periapical healing phase following root canal treatment. Literature review: The pathogenesis of apical periodontitis involves degradation of several extracellular matrix components. Matrix metalloproteinases (MMPs) are expressed in response to specific stimuli by resident cells of connective tissue during tissue remodeling and by inflammatory cells that arrive into the surrounding tissues during inflammatory events. MMPs have been reported in apical periodontitis, either experimentally induced or obtained from humans and there is evidence that these enzymes show diff erent expression patterns in granulomas and periapical cysts. Root canal therapy is important for the reduction of periapical inflammation as well as the synthesis of MMPs, especially when using a calcium hydroxide-based dressing. Conclusion: Apical periodontitis show high expression of matrix metalloproteinases and root canal treatment results in less expression of MMPs when compared to untreated apical periodontitis

Implant osseointegration in circumferential bone defects using latexderived proteins, autogenous bone graft and guided bone regeneration. A comparative study in the dog mandible

Diversas pesquisas têm direcionado esforços na busca de biomateriais que fossem capazes de melhorar a osseointegração e a estabilidade de implantes dentais em regiões anatômicas desfavoráveis. Entretanto, muitas das opções de terapias regenerativas, largamente empregadas em cirurgias orais reconstrutivas, estão associadas à algumas desvantagens clínicas como um grande período de recuperação, alto risco de morbidade, risco de parestesia nos pacientes, além de apresentarem alto custo. Biomateriais obtidos a partir do látex natural extraído da Hevea brasilienses (seringueira) demonstraram apresentar propriedades angiogênicas e significante aumento no reparo ósseo de alvéolos dentais e em defeitos de calota de ratos. Considerando os benefícios da angiogênese no processo de reparação óssea, o objetivo deste trabalho foi avaliar a capacidade osteogênica proporcionado pelas proteínas angiogênicas do látex na otimização do processo de osseointegração e na estabilidade de implantes de titânio instalados em defeitos ósseos cicunferenciais. Dez cães foram submetidos às cirurgias de instalação de implantes no centro de defeitos ósseos, após a exodontia dos pré-molares. Os defeitos ósseos em cada animal foram preenchidos com coágulo, osso autógeno, proteínas angiogênicas do látex associada ao gel carreador ou gel carreador (apenas gel de colágeno associado ao ácido hialurônico, sem a presença de implante). Em um dos lados da mandíbula os implantes foram recobertos por membrana não absorvível de e-PTFE sem reforço de titânio, ao passo que no lado contralateral, os implantes foram recobertos apenas pelo retalho mucoperiosteal. Metade dos animais foram sacrificados após 4 semanas e o restante após 12 semanas pós-operatórias. A estabilidade dos implantes foi avaliada através de análise de freqüência de ressonância e a formação óssea foi analisada por meio de histologia, histomorfometria, análise qualitativa e quantitativa de fluorescência. Os resultados numéricos obtidos foram submetidos à análise de variância (ANOVA) e contrastes ortogonais foram realizados para comparações múltiplas. Histologicamente, observou-se para todos os biomateriais, uma formação de osso imaturo e lamelar no tempo de 4 e 12 semanas, respectivamente. Na análise qualitativa de fluorescência, encontrou-se maior atividade óssea no período inicial de avaliação (p≤0,05). A membrana não mostrou efeito significativo no processo de regeneração óssea e não houve diferença estatística entre os diferentes biomateriais testados (p≥0,05). O gel carreador apresentou menor formação óssea quando comparado aos demais materiais, sem considerar o tempo e a presença da membrana (p≤0,05). Houve um aumento significativo da formação óssea, osseointegração e da estabilidade ao longo do tempo para os diferentes biomateriais empregados (p≤0,05), independente da presença da membrana. O grupo das proteínas angiogências do látex mostraram formação óssea similar ao coágulo e ao osso autógeno em 4 e 12 semanas, respectivamente (p≥0,05). Os biomateriais obtiveram significante formação óssea, osseointegração e estabilidade dos implantes ao longo do período de avaliação experimental. Esta pesquisa mostrou que a regeneração óssea guiada não alterou os resultados histométricos, as proteínas angiogênicas do látex promoveram deposição óssea similar ao coágulo e osso autógeno nos defeitos alveolares, observou-se um aumento do processo de ossoeintegração e da estabilidade dos implantes em todos os sítios experimentais, independente do tratamento instituído.The development of biomaterials that can assist osseointegration and implant stability in dissatisfactory anatomical regions has been the goal of several researches in the past years. Despite the array of regenerative therapies to be used, some clinical disadvantages still persist, such as considerable patient morbidity, extended patient recovery periods, substantial cost, risk of paresthesia and residual defects in the donor site. Natural latex biomaterials from Hevea brasiliensis (rubber tree) have shown promising advantages, such as angiogenic properties, significantly high bone repair in dental alveoli, easy acquisition and handling, biocompatibility, reduced cost, dispensability of donor sites and very little chance of morbidity. Considering the well-known benefits of angiogenesis in the bone healing process, the purpose of this study was to evaluate the osteogenic capacity of angiogenic latex proteins in accelerating osseointegration and implant stability, when placed in circumferential bone defects. Ten male dogs were underwent an implant placement in center of the defects after pre-molar extractions. The circumferential gaps around the implant were filled either with coagulum, particulate autogenous bone graft, latex angiogenic proteins mixed in a gel carrier, or with collagen and hyaluronic acid gel carrier without implants. Circumferential defects were covered with a non-absorbable e-PTFE membrane on one side and left uncovered on the other. Half the animals were sacrificed 4 and 12 weeks after implant placement. Implant stability was evaluated using resonance-frequency analysis and bone formation was analyzed by histological, histometric, qualitative and quantitative bone labeling analysis. Data were analyzed statistically using ANOVA and orthogonal contrasts for multiple comparisons. Immature and lamellar bone were observed at 4 and 12 weeks, respectively. Bone labeling analysis showed more bone activity on early period of healing (p≤0.05). The membrane did not show significant effect on bone regeneration and there was not statistical difference among the different biomaterials, considering the different time evaluation periods (p≥0.05). Gel carrier group showed less bone formation than other filling materials, not considering recovery time and membrane (p≤0.05). Latex angiogenic proteins showed bone regeneration similar to coagulum and bone graft at 4 and 12 weeks, respectively (p≥0.05). There was significant bone formation, osseointegration and implant stability of biomaterials during the entire healing period. This research showed that guided bone regeneration technique did not change the histometric results; latex angiogenic proteins promoted bone deposition similar to coagulum and bone graft on alveolar bone defects; osseointegration process and implant stability occurred in all experimental sites, regardless of the treatment performed

Diabetes Mellitus modify the osteogenesis signaling and compromise bone repair after rapid maxillary expansion

Introdução: O diabetes mellitus (DM) é uma doença crônica caracterizada pela hiperglicemia associada a diversas alterações sistêmicas e uma das suas complicações é o processo de reparo ósseo comprometido. Entretanto, ainda não há estudos utilizando análises celulares e biomoleculares que avaliem o processo de reparo ósseo desta desordem metabólica quando associada à expansão rápida da maxila (ERM). Objetivo: O objetivo deste estudo foi avaliar a remodelação óssea e sinalização osteogênica durante a aplicação de mecânica ortodôntica para ERM em ratos diabéticos tipo1- induzidos. Material e Métodos: Cento e cinquenta ratos Wistar, machos, foram divididos aleatoriamente em seis grupos de estudo. Grupos: controle (C, n=30), veículo (V, n=15), diabetes mellitus tipo 1 induzido com estreptozotocina (D, n=30), controle submetido à ERM (Cd, n=30), veículo submetido à ERM (Vd, n=15) e diabetes mellitus tipo 1 induzido com estreptozotocina submetido à ERM (Dd, n=30). Os animais foram eutanasiados aos 3, 7 e 10 dias após ERM . Análises histológicas, mudanças no padrão de expressão gênica e proteica de osteoprotegerina, (OPG), RANK, RANKL, osteonectina (ONC), osteocalcina (OCC), sialoproteína óssea (BSP), osteopontina (OPN) e proteína morfogenética óssea 2 (BMP2), assim como as mudanças no peso corporal, na ingestão de água na glicemia foram avaliadas. A análise da expressão gênica e proteica foram realizadas por qRT-PCR e Western Blotting, respectivamente. Os dados foram submetidos ao teste estatístico ANOVA de duas vias e pós-teste de Tukey (α= 0,05). Resultados: Histologicamente no grupo Dd foi notado maior reabsorção óssea, com diversas áreas em degradação com ausência de osteoblastos, intensa atividade de reabsorção óssea solapante, presença de osteoclastos, células inflamatórias associada ao comprometimento da formação óssea quando comparado aos grupos D e Cd. Estes resultados foram confirmados também nos achados moleculares, uma vez que algumas sinalização gênicas e proteicas relacionadas a osteogênese foram reduzidas, ao passo que a sinalização osteoclastogênica foi estimulada, principalmente no período inicial de reparo ósseo. No grupo D, o processo de formação ósseo estava atrasado comparado ao grupo C, devido a alteração da expressão dos genes e proteínas que regulam o catabolismo e anabolismo ósseo, haja vista que havia maior presença de tecido ósseo imaturo e maior quantidade de áreas de remodelação ativa até o período mais tardio de estudo. No grupo Cd foi observado remodelação óssea, caracterizada por um tecido desorganizado na região da sutura palatina mediana, com intensas áreas inflamatórias, hemorrágicas e reabsortivas comparado ao grupo C. Contudo, até o período de 10 dias pós abertura da sutura, não foi possível observar o completo preenchimento do gap sutural por tecido ósseo. Estes resultados histológicos foram observados na sinalização de genes e proteínas no grupo Cd, uma vez que estes biomarcadores de formação e reabsorção óssea estavam alterados quando comparados aos grupos C e Dd. Conclusões: O DM alterou a sinalização para o metabolismo ósseo e atrasou o processo de reparo após ERM. Estes resultados reforçam a necessidade de avaliar o status do metabolismo ósseo dos pacientes durante tratamento ortopédico e/ ou ortodôntico, visto que a aplicação destas forças na presença do DM podem promover efeitos indesejáveis.Background: Diabetes mellitus (DM) is a disease associated with several disorders of health in humans and one of the most important is the jeopardizing of bone formation. However, to the best of our knowledge there is no information about the influence of diabetes on orthodontic and orthopedic treatment at cellular and molecular levels. Objective: The aim of this study was to evaluate bone remodeling process in palatal suture during orthopedic mecanotherapy in rats with type 1-induced diabetes mellitus. Material and Methods: One hundred and fifty Wistar male rats were randomly assigned to six groups. Groups: control (C, n=30), vehicle (B, n=15), type 1-induced diabetes mellitus using streptozotocin (D, n=30), control with RME (C+RME, n=30), vehicle with RME (C+RME, n=15) and type 1-induced diabetes mellitus using streptozotocin with RME (D+RME, n=30). The animals were euthanized at 3, 7 and 10 days after RME. Histologic evaluations, changes in genes and proteins expression of osteoprotegerin (OPG), RANK, RANKL, osteonectin (ONC), osteocalcin (OCC), bone sialoprotein (BSP), osteopontin (OPN) and bone morphognetic protein 2 (BMP2) were evaluated along with the changes in body weight, water intake and glycemic profile. Real-Time RT-PCR and Western Blotting were used to evaluate gene and the protein expression. Data were submitted to statistical analysis using two-way ANOVA followed by Tukey test ( α= 0,05). Results: On group D+RME it was observed an increased bone resorption, serveral undermining and tissue degradation areas. On the suture gap there were mainly inflammatory and osteoclasts cells associated with compromised bone formation compared to groups D and Cd. These results were observed also in molecular levels, since there were a reduced osteogenesis and an upregulation of osteoclastogenesis, mainly in early period of healing. On group D, bone formation was compromised compared to group C, due to changes on genes and proteins expression which regulates bone metabolism, considering that there was more immature bone and incresead active remodeling areas until late periods. On group Cd it was observed bone remodeling, characterized by desorganized tissue on the gap of midpalatal suture, with intense inflammatory hemorhagic and resorptive areas compared to group C. However until 10 days after RME, on group D the gap was not completely filled with bone tissue. These results were observed on the signaling of molecular biomarkers on group Cd, since they were changed compared to groups C and Dd. Conclusions: DM modify the signaling for bone metabolism and compromise bone repair after RME. During orthopedic and orthodontic treatment is necessary to evaluate metabolism status of subjects, since the application of these forces have been shown to promote undesirable effects mostly when associated with DM

A retrospective study of zygomatico-orbital complex and/or zygomatic arch fractures over a 71-month period

Background/Aim: The aim of this retrospective study was to evaluate the epidemiology, treatment, and complications of zygomatico-orbital complex (ZOC) and/or zygomatic arch (ZA) fractures either associated with other facial fractures or not over a 71-month period. Material and methods: This survey was performed in three hospitals of Ribeirao Preto in Sao Paulo, Brazil, from August 2002 to July 2008. The records of 1575 patients with facial trauma were reviewed. There were 140 cases of ZOC and ZA fractures either associated with other facial fractures or not. Data regarding gender, age, race, addictions, day of trauma, etiology, signs and symptoms, oral hygiene condition, day of initial evaluation, hospital admission, day of surgery, surgery approach, pattern of fractures, treatment performed, post-operative antibiotic therapy, day of hospital discharge, and post-operative complications were collected. The data were subjected to descriptive statistical analyses. Results: The most frequent fractures affected Caucasian men and occurred during the fourth decade of life. The most frequent etiology was traffic accident, and symptoms and signs included pain and edema. Type I fractures were the main injury observed, and the treatment of choice was always rigid internal fixation. Post-operative antibiotic therapy was solely employed when there was an indication. Complications were observed in 13.1% of the cases. Conclusions: The treatment protocol yielded suitable post-operative results and also showed success rates comparable to published data around the world.FAPESP, The State of Sao Paulo Research Foundation[2006/50017-3