NÃO HÁ MAL QUE SEMPRE DURE / THERE IS NO EVIL THAT ALWAYS LASTS

Há quatro anos, uma mulher brilhante, culta e altiva, jurista e política experiente e propositiva, Hillary Clinton, foi derrotada no colégio eleitoral estado-unidense (mesmo vitoriosa na totalização dos votos de cidadãos eleitores que participaram deste processo obsoleto se comparado com o das melhores Democracias do planeta Terra). Aceitável, face às regras vigentes, mas trágico pelo vencedor ter sido, ao longo de seu mandato, um nacionalista retrógrado em tempos de saudável globalização, um revisionista da História e um desrespeitador da Ciência (e de nossas inteligências: emocional, política e ética).

Peri-implant osseointegration after low-level laser therapy: micro-computed tomography and resonance frequency analysis in an animal model.

The purpose of the present study is to evaluate the effects of low-level laser therapy on the osseointegration process by comparing resonance frequency analysis measurements performed at implant placement and after 30 days and micro-computed tomography images in irradiated vs nonirradiated rabbits. Fourteen male New Zealand rabbits were randomly divided into two groups of seven animals each, one control group (nonirradiated animals) and one experimental group that received low-level laser therapy (Thera Lase®, aluminum-gallium-arsenide laser diode, 10 J per spot, two spots per session, seven sessions, 830 nm, 50 mW, CW, Ø 0.0028 cm2). The mandibular left incisor was surgically extracted in all animals, and one osseointegrated implant was placed immediately afterward (3.25ø × 11.5 mm; NanoTite, BIOMET 3i). Resonance frequency analysis was performed with the Osstell® device at implant placement and at 30 days (immediately before euthanasia). Micro-computed tomography analyses were then conducted using a high-resolution scanner (SkyScan 1172 X-ray Micro-CT) to evaluate the amount of newly formed bone around the implants. Irradiated animals showed significantly higher implant stability quotients at 30 days (64.286 ± 1.596; 95 % confidence interval (CI) 60.808-67.764) than controls (56.357 ± 1.596; 95 %CI 52.879-59.835) (P = .000). The percentage of newly formed bone around the implants was also significantly higher in irradiated animals (75.523 ± 8.510; 95 %CI 61.893-89.155) than in controls (55.012 ± 19.840; 95 %CI 41.380-68.643) (P = .027). Laser therapy, based on the irradiation protocol used in this study, was able to provide greater implant stability and increase the volume of peri-implant newly formed bone, indicating that laser irradiation effected an improvement in the osseointegration process.

Histomorphometric assessment of the influence of low-level laser therapy on peri-implant tissue healing in the rabbit mandible.

OBJECTIVE: The purpose of this study was to demonstrate the effect of low-level laser therapy (LLLT) on the peri-implant bone healing process in the rabbit mandible. BACKGROUND DATA: LLLT has been shown to accelerate tissue repair and osseointegration of implants placed into the rabbit tibia. However, the beneficial effects of LLLT have never been tested in the rabbit mandible, which would more closely mimic the human situation. MATERIALS AND METHODS: Twenty-four male New Zealand rabbits were randomly divided into four groups of six animals each. All animals had their left mandibular incisors extracted, followed by immediate insertion of a titanium dental implant in the fresh socket. Three groups received LLLT [aluminum-gallium-arsenide (AlGaAs), λ=830nm, 50 mW, continuous wave (CW)] at three different energy densities per treatment session (E-5, 5 J/cm(2); E-10, 10 J/cm(2); and E-20, 20 J/cm(2)). Irradiation was performed every 48 h for 13 days, totaling seven sessions. One group received sham treatment (controls). Histological sections were obtained from each of the 24 mandibles dissected, without first decalcifying the specimens, and were stained with hematoxylin and eosin and Picrosirius red for histomorphometric evaluation. Bone-to-implant contact (BIC), bone formation area, and collagen fiber area were assessed by light microscopy. RESULTS: Significant differences were found between group E-20 and all other groups (p<0.05). Histomorphometric evaluation showed significantly higher BIC and significantly more collagen fibers in group E-20. CONCLUSIONS: Photobiostimulation with LLLT at an energy density of 20 J/cm(2) per session had a significant positive effect on new bone formation around dental implants inserted in the rabbit mandible.

Finite element analysis of masticatory stress on neoformed bone tissue after distraction osteogenesis and low-level laser therapy: a pilot study.

OBJECTIVE: This study aimed to understand the action of masticatory forces on an implant virtually introduced into the sheep mandible after distraction osteogenesis and low-level laser therapy (LLLT) by using finite element analysis. BACKGROUND DATA: Distraction osteogenesis as an alternative for bone reconstruction that may be used in the treatment of deformities. METHODS: Four ewes underwent distraction osteogenis to elongate the left mandibular body by 15 m, and three of them underwent LLLT with the purpose of improving bone properties. After death, animals were scanned by computed tomography and their mandibles were tridimensionally reconstructed by computer programs. The physical properties related to hardness and modulus of elasticity of each animal were obtained from the dissected mandibles, and data were transferred to Femap software for finite element analysis. RESULTS: Animals exposed and not exposed to LLLT irradiation showed remarkably similar values for superficial hardness and modulus of elasticity, without statistically significant difference (p>0.05), between the values observed for the cortical bone and the cancellous bone among the groups. The neoformed mandible, after a brief period for bone healing, was able to promote stability for implant placement and proper distribution of masticatory forces. CONCLUSIONS: An implant introduced virtually into the site of bone neoformation did not suffer any micromotions relevant to osteointegration. Furthermore, finite element analysis showed that the neoformed portion of the mandible was able to absorb and distribute masticatory forces throughout its structure, even after a brief period for bone maturation.

Systemic effects of LLLT on bone repair around PLLA-PGA screws in the rabbit tibia.

To evaluate the systemic effects of low level laser therapy (LLLT) on the early stages of bone repair after implantation of poly-L-lactic/polyglycolic acid (PLLA-PGA) screws 24 rabbits were randomly allocated to one of two groups, experiment or control. Each animal underwent implantation of one 5 × 1.5 mm PLLA-PGA screw in each tibia (right and left). The experiment group received infrared laser irradiation (830 nm, 4 J, 100 mW, 10.1 s) over the right paw immediately after implantation and every 48 h thereafter, for a maximum of seven sessions. The control group was not irradiated. Both groups were divided into three subgroups according to the observation period (5, 15, or 30 days), after which animals were euthanized. The results observed in the left paw of experimental animals were compared with the left paws of control animals. We also compared the right and left paws of experimental animals so as to compare local and potential systemic effects. Bone specimens were analyzed to assess the extent of peri-implant bone formation, quantitative analysis revealed greater bone formation in the left tibia of experimental animals as compared to controls on 5-day follow-up. Descriptive analysis revealed slightly larger and thicker trabeculae in the irradiated animals at 5 days post-procedure. There were no significant differences at any other point in time. As used in this study, LLLT had a positive systemic effect on the early stages of bone formation.

Metodologia para avaliação do efeito sistêmico e local da LLLT na osseointegração de implantes dentários em mandíbula de coelhos: nota prévia / Methodology protocol for assess systemic and local effects of LLLT on osseointegration of dental implants in the rabbits jaws

Objetivos: descrever a técnica cirúrgica e a sequência laboratorial utilizada na obtenção de dados por meio de dosagem hormonal, análise da frequência de ressonância (AFR), tomografia computadorizada de feixe cônico (TCFC), microscopia eletrônica de varredura (MEV), espectrometria por dispersão de energia (EDS) e análise histológica e histomorfométrica da região perimplantar pós-terapia com laser não ablativo (LLLT) em modelo experimental coelho. Materiais e método: foram utilizados 40 coelhos machos, raça Nova Zelândia, distribuídos em cinco grupos, sendo dois grupos designados controle (CI e CII) e três grupos designados experimentais (EI, EII, EIII). Os cinco grupos foram submetidos a coletas sanguíneas para dosagens de tri-iodotironina (T3), tiroxina (T4), cálcio e albumina, sendo o grupo CI considerado controle hematológico absoluto. Nos demais grupos (CII, EI, EII e EIII), foram realizadas a extração do incisivo inferior esquerdo e a colocação de um implante imediato com aferição da frequência de ressonância (AFR). Nos grupos experimentais, foi realizada laserterapia com três doses distintas (EI=70J/cm2, EII=35J/cm2, EIII=140J/cm2). Aos 45 dias, os animais dos grupos CII, EI, EII e EIII foram novamente submetidos à aferição da frequência de ressonância, foram mortos e tiveram suas mandíbulas dissecadas e avaliadas por TCFC, MEV e EDS. As mandíbulas foram incluídas, seccionadas e coradas com coloração de HE, picrosirius- -red e azul de toluidina para análise histomorfométrica da extensão linear de contato entre osso e implante (ELCOI) e a área óssea (AO) por meio de microscopia ótica. Considerações finais: apresenta-se um roteiro que pode servir de modelo para colegas pesquisadores.

Objectives: to describe surgical and laboratorial techniques used in an experimental rabbit model. The aim of the study was to obtain data using the following techniques: hormonal dosage, resonance frequency analysis (RFA), cone beam computed tomography (CBCT), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), peri-implant histological and histomorphometric analysis after low-level laser therapy (LLLT). Materials and method: a total of 40 New Zealand male rabbits were divided into five groups. Two groups designated control (CI and CII) and three groups designated experimental (EI, EII, EIII). All groups underwent blood sampling for measurements of triiodothyronine (T3) and thyroxine (T4), calcium and albumin, with the CI group being considered absolute hematological control. For the other groups (CII, EI, EII and EIII) the extraction of the lower left incisor was performed followed by placement of an immediate implant with measurement of resonance frequency. The experimental groups were subjected to laser therapy with three different doses (EI = 70J/cm2, EII = 35J/cm2, EIII = 140J/cm2). Groups CII, EI, EII and EIII were subjected to the measurement of resonance frequency after 45 days, killed and the jaw was dissected to be evaluated by CBCT, SEM and EDS. Then, the samples were included, sectioned and stained with HE staining, picrosirius-red and toluidine blue for histomorphometric analysis by linear extent of bone-implant contact (BIC) and bone area (BA) using light microscopy. Final considerations: a technical sequence that can provide a model for fellow researchers was presented.

Conservative treatment of the dentigerous cyst: report of two cases

The purpose of this paper is to present two cases of dentigerous cyst associated to permanent teeth in children treated by conservative techniques. Dentigerous cyst is the most common developmental cysts of the jaws. Conservative treatment is very effective to this entity and aims at eliminating the cystic tissue and preserving the permanent tooth involved in the pathology. Two techniques are described as conservative treatment for these cysts, marsupialization and the decompression. Two children presented with dentigerous cysts. A female child was affected by a large lesion at the right side of the mandible associated to tooth 45. The other lesion arose at the left maxilla associated to tooth 21 of a male child. Each dentigerous cyst promoted severe tooth displacement. The first patient was treated with decompression and the second with marsupialization.

Effect of low-level laser therapy on incorporation of block allografts.

OBJECTIVE: To assess the effect of low-level laser therapy (LLLT) on the incorporation of deep-frozen block allografts in a rabbit model. BACKGROUND DATA: Studies have shown that LLLT has beneficial effects on tissue repair and new bone formation. METHODS: Bone tissue was harvested from two rabbits, processed by deep-freezing and grafted into the calvaria of 12 animals, which were then randomly allocated into two groups: experimental (L) and control (C). Rabbits in group L were irradiated with an aluminum gallium arsenide diode laser (AlGaAs; wavelength 830 nm, 4 J/cm(2)), applied to four sites on the calvaria, for a total dose of 16 J/cm(2) per session. The total treatment dose after eight sessions was 128 J/cm(2). Animals were euthanized at 35 (n = 6) or 70 days (n = 6) postoperatively. RESULTS: Deep-freeze-processed block allografts followed by LLLT showed incorporation at the graft-host interface, moderate bone remodeling, partial filling of osteocyte lacunae, less inflammatory infiltrate in the early postoperative period, and higher collagen deposition than the control group. CONCLUSION: Optical microscopy and scanning electron microscopy showed that allograft bone processed by deep-freezing plus LLLT is suitable as an alternative for the treatment of bone defects. Use of the deep-freezing method for processing of bone grafts preserves the structural and osteoconductive characteristics of bone tissue.

Avaliação do efeito biomodulatório local e à distância por laserterapia infravermelha e vermelha na cicatrização de feridas cutâneas em dorso de ratos / Analysis of local and distant biomodulatory effects by red and infrared lasertherapy on cutaneous wounds healing on the dorsum of rats

Objetivos: Este estudo tem por objetivo verificar se os lasers vermelho e infravermelho podem, ou não, interferir no processo cicatricial de ferimentos localizados no ponto de aplicação e a distância deste. Materiais e métodos: Foram realizados três ferimentos circulares em dorso de ratos, na região cranial, na região medial e na região caudal. Para este estudo experimental foram analisados 45 animais, divididos em três grupos, onde 15 animais não sofreram irradiações, em 15 animais foi aplicado laser infravermelho e em 15 animais foi aplicado laser vermelho. O período de observação foi de três, cinco e sete dias. Assim, cada grupo foi dividido em três subgrupos (A; B; C), de acordo com período de observação. Para os grupos II e III a dose de energia das irradiações foi de 8J/cm2, aplicados após o término da cirurgia e a cada 48 horas, totalizando, na dependência da época da morte do animal, duas, três ou quatro irradiações. Resultados: Houve maior presença de edema e processo inflamatório agudo nos primeiros dias avaliados e quantitativamente não houve diferença estatisticamente significante no percentual de redução das feridas intra e inter-grupos. Conclusões: A fototerapia por laser de baixa potência infravermelha apresentou um efeito biomodulatório positivo nos períodos iniciais de cicatrização e reparo em feridas no dorso de ratos. A fototerapia por laser de baixa potência vermelha apresentou, nos períodos iniciais analisados, maior processo inflamatório agudo, o que pode ser devido ao menor comprimento de onda que atinge as camadas mais superficiais da ferida.

Objectives: This study aims to verify whether red and infrared lasers can interfere with the healing process ofwounds located at the point ofapplication and at distance. Materials and methods: Three circular wounds were conducted on the dorsum of rats, being one in the cranial region, another one in the medial reg ion, and a third one in the caudal region. For thisexperimental study, 45 animals wereinvestigated and divided into threegroups, to which 15 animals weresubmitted to no laser of any kind, 15 animals were submitted to infrared laser, and 15 animals were submitted tored laser. The observation periodwas of three, five, and seven days.Thus, each group was divided into three subgroups (A, B,C) based on the observation period. For groups II andIII the amount of energy during theirradiation was 8J/cm 2, appliedafter the surgery and then every 48hours, totalizing, depending on thetime of death of the animal, two,three or four irradiations. Results: There was higher presence of edema in among 3 and 5 day period of analysis and acuteinflammatory proces s were found in red laser irradiation study group.Quantitatively, there was no statistically significant difference in the percentage of reduction of wounds in and among the groups. Conclusions: There is no statistical difference were found by thetherapy with low power red and infra-red laser in the wound sizes during all period of analysis.

Immunohistochemical assessment of the MIB, CK-14, p63, p16, Cal A, and Cys A markers in spindle cell squamous cell carcinomas of the lip / Avaliação imuno-histoquímica dos marcadores MIB, CK-14, p63, p16, Cal A e Cys em carcinomas espinocelulares de lábio

Objective: with the objective of testing the expression of the protein markers MIB, CK14, p63, p16, Cal A, and Cys A in the pathogenesis of oral spindle cell carcinoma, we conducted an immunohistochemical study of the expression of the protein markers MIB, CK14, p63, p16, Cal A, and Cys A in human biopsy specimens of these lesions. Methods: fifteen histological specimens of spindle cell squamous cell carcinoma of the lower lip were obtained from the Department of Oral Pathology, Bahia Federal University. Immunohistochemical analyses were performed at the Molecular Biology Laboratory of the Department of Otorhinolaryngology, Heidelberg University, Germany. Results: statistical analysis revealed no association between markers. There was strong positive staining for Ck14, MIB, and Cal A in 93.3% of cases, thus establishing a strong association. Conclusion: p63, p16, MIB, Cal A, Cys A are markedly expressed and p16 is strongly suppressed in oral cavity tumors, which suggests that the latter protein may play a role in negative regulation of cell cycle progression.

Assessment of marginal adaptation after apicoectomy and apical sealing with Nd:YAG laser.

OBJECTIVE: Recurrent periapical disease poses a substantial challenge to the dental practitioner. However, the use of novel methods and materials in periapical surgery has increased the success rates of treatment. The objective of this study was to assess the effects of mineral trioxide aggregate (MTA) retrofilling and apical sealing with Nd:YAG laser (at 10 Hz, 150 mJ, 1.5 W, in 60 sec pulses) as adjuncts to apicoectomy. METHODS: Perpendicular root end resection was performed with diamond-coated burs on 40 canine teeth previously subjected to endodontic treatment. Teeth were randomly allocated into four groups: group A, apicoectomy alone; group B, apicoectomy+Nd:YAG laser; group C, apicoectomy+MTA retrofilling; group D, apicoectomy+MTA retrofilling+Nd:YAG laser. Specimens were embedded in epoxy resin and sliced lengthwise and crosswise. RESULTS: Scanning electron microscopy (SEM) analysis showed more homogeneous and canaliculi-free apical surfaces in groups B and D (p<0.01). Marginal gaps between the dentin surface and filling material were observed in decreasing order of gap size in groups B, A, D, and C (p<0.01) for cross-sectional analysis. Energy-dispersive X-ray spectrometry (EDS) revealed greater phosphorus (p<0.01) and lower calcium (p<0.01) ion content in the Nd:YAG-irradiated groups. CONCLUSIONS: In this study, Nd:YAG laser irradiation had a positive effect on dentin surface sealing, despite an untoward dimensional effect when associated with MTA retrofilling.

Assessment for treatment of tripod fractures of the zygoma with microcompressive screws.

PURPOSE: The present prospective study sought to evaluate a new rigid internal fixation device called a "neck screw," which was applied to patients presenting with a tripod fracture of the zygomaticomaxillary complex. PATIENTS AND METHODS: Seventeen patients with tripod fractures received surgical treatment from 2007 to 2010, and had their zygomaticomaxillary complex monofragments fixed using the neck screw protocol. The adequacy of fracture reduction, stability of the zygomatic monofragment after fixation, cosmetic outcomes, and postoperative complications were used to determine the efficacy of this protocol. The stability provided by the neck screw was evaluated by computed tomography (CT) scans by comparing the immediate postoperative distances between the fractured bone segments (control group) with those distances measured on CT scans obtained 5 weeks later (late group). RESULTS: The average distance observed between the fractured ends on the immediate postoperative CT scan was less than 0.58 mm, demonstrating adequate fracture reduction. No significant changes were seen in these postoperative values after 5 weeks (Wilcoxon test, P = 1.0000), demonstrating no displacement of the zygomaticomaxillary complex monofragment after fixation using the neck screw. CONCLUSIONS: The proposed surgical treatment proved efficient in 17 patients. The fixation stability provided by the neck screw was confirmed by subsequent CT scan measurements, statistical analysis, and clinical follow-up during the postoperative period, in which patients showed no significant associated complications, facial asymmetry, enophthalmos, or diplopia.

Retinoblastoma and p53 protein expression in pre-malignant oral lesions and oral squamous cell carcinoma.

The retinoblastoma (Rb) and p53 genes play a fundamental role in cell cycle mechanisms, and their deregulation is related to many steps of oral cancer carcinogenesis. This study was conducted to evaluate the expression of the p53 and Rb proteins in malignant and pre-malignant oral cavity lesions. This retrospective study was conducted at the Federal University of Bahia, Salvador, Brazil, and the Molecular Biology Laboratory of the Otorhinolaryngology Department at the University of Heidelberg, Heidelberg, Germany. Excisional biopsy samples of oral cavities were collected from patients with suspected oral lesions. The samples were processed by immunohistochemistry to be classified by a semi-quantitative score: samples with a ≤ 10% positivity were considered to have weak/negative expression (-); those with 11-50% positivity, moderate expression (+); and those with >50% positivity, high expression (++). Seventy-one patients were studied (75% male; median age, 52 years; range, 24-84). Of the samples studied, 59.4% were oral squamous cell carcinoma (OSCC) and 40.6% were pre-neoplastic lesions (leukoplakia and actinic cheilitis). OSCC presented higher expression of Rb protein compared to pre-malignant lesions: 75 vs. 25% (p<0.001). Pre-neoplastic lesions presented higher expression of p53 protein compared to OSCC lesions: 55.2 vs. 44.8% (p = 0.030). Despite the small number of samples, the expression of these cell cycle biomarkers (p53 and Rb protein) in excisional biopsies suggests that molecular lesion assessment can determine pre-malignant lesions, and that its use may improve the clinical and surgical treatment of early lesions. Thus, p53 protein expression may be related to the early steps of carcinogenesis in OSCC. Finally, a higher Rb expression was also observed in malignant lesions.

Osteoinduction of human bone marrow cells: an in vitro study / Introdução osteogênica de células da medula óssea humana: um estudo in vitro

Objective: This study evaluated the osteogenic induction of human bone marrow cells by human recombinant bone morphogenetic protein-4 (rhBMP-4) and proteins released by Saos-2 (human osteosarcoma cell line). Study design: Osteoinduction in the presence or absence of Saos-2 and/or rhBMP-4 was evaluated in cultured human bone marrow cells. Morphological aspects and bone protein markers (osteonectin, osteopontin, and osteocalcin) were analyzed on days 1, 2, 5, 8, 11 and 14. Osteonectin expression was evaluated using immunohistochemistry with anti-secreted protein acidic and rich in cystein (anti-SPARC) antibody. mRNA transcripts for osteopontin were determined using RT-PCR with specific primers. Results: Bone marrow cells were adherent since the first day of culture and were positive for osteonectin. mRNA transcripts were detected in all culture conditions since the first day of culture. As human osteosarcoma cells are a source of additional growth they did not affect osteoinduction. rhBMP-4 up regulates osteoinduction during the first days of culture only. Osteoblasts were obtained from human bone marrow cells even in the absence of growth factors and showed a typical morphology. Cells derived from bone marrow can undergo osteoinduction in vitro in the absence of osteoinductive factors such as bone morphogenetic proteins. Conclusions: This study showed that an osteoblastic cell lineage may be obtained from human bone marrow derived from adherent cells, and that the presence of the rhBMP-4 seems to have an effect during the first stages of differentiation only.

A preliminary study of hardness and modulus of elasticity in sheep mandibles submitted to distraction osteogenesis and low-level laser therapy

Objectives: To investigate the quality of newly formed bone in sheep mandibles submitted to distraction osteogenesis and low-level laser therapy (LLLT), based on hardness and modulus of elasticity values. The ideal moment for laser application (during the latency/activation period vs. during the bone consolidation period) was also evaluated. Computed tomography imaging was used to assess relapse as a result of early device removal. Study design: Extraoral distraction devices were placed in five sheep so as to achieve 1.5 cm of lengthened bone in 60 days. Distraction devices were removed 50, 40, and 33 days after surgery. Four animals were treated with LLLT, at different times, and one was used as control (no LLLT).Results: When applied during the bone consolidation period, LLLT caused an increase in hardness and modulus of elasticity values. On the other hand, animals irradiated with LLLT during the latency/activation period presented adelay in bone healing. A period of consolidation of 13 days (early device removal) was associated with relapse. Conclusions: Nanoindentation tests were able to detect slight abnormalities in bone metabolism and proved to be important tools for the assessment of bone quality following distraction osteogenesis. LLLT provided increased benefits when applied during the bone consolidation period, once it promoted an increase in hardness and modulus of elasticity values. According to our results, the bone consolidation period should be of at least 3 weeks, so as to prevent relapse (AU)

A preliminary study of hardness and modulus of elasticity in sheep mandibles submitted to distraction osteogenesis and low-level laser therapy.

OBJECTIVES: To investigate the quality of newly formed bone in sheep mandibles submitted to distraction osteogenesis and low-level laser therapy (LLLT), based on hardness and modulus of elasticity values. The ideal moment for laser application (during the latency/activation period vs. during the bone consolidation period) was also evaluated. Computed tomography imaging was used to assess relapse as a result of early device removal. STUDY DESIGN: Extraoral distraction devices were placed in five sheep so as to achieve 1.5 cm of lengthened bone in 60 days. Distraction devices were removed 50, 40, and 33 days after surgery. Four animals were treated with LLLT, at different times, and one was used as control (no LLLT). RESULTS: When applied during the bone consolidation period, LLLT caused an increase in hardness and modulus of elasticity values. On the other hand, animals irradiated with LLLT during the latency/activation period presented a delay in bone healing. A period of consolidation of 13 days (early device removal) was associated with relapse. CONCLUSIONS: Nanoindentation tests were able to detect slight abnormalities in bone metabolism and proved to be important tools for the assessment of bone quality following distraction osteogenesis. LLLT provided increased benefits when applied during the bone consolidation period, once it promoted an increase in hardness and modulus of elasticity values. According to our results, the bone consolidation period should be of at least 3 weeks, so as to prevent relapse.

Terapêutica com bisfosfonatos: implicações no paciente odontológico - revisão de literatura / Therapy with bisphosphonates: implications for dental patient - literature review

Objetivos: Revisar a literatura científica sobre os bisfosfonatos (BPs), suas indicações e contraindicações terapêuticas, mecanismo de ação e efeitos colaterais que podem ocorrer em pacientes submetidos a essa terapia medicamentosa e verificar a interferência da LLLT (laserterapia de baixa potência) no tratamento da osteonecrose. Revisão de literatura: Os BPs causam uma alteração no remodelamento ósseo, diminuindo a reabsorção óssea mediada por osteoclastos. São fármacos utilizados no tratamento de diversas desordens ósseas, entre as quais osteoporose, neoplasias malignas com metástase óssea, hipercalcemia maligna e mieloma múltiplo. O uso crônico dos bisfosfonatos pode cau-sar como efeito colateral a osteonecrose dos maxilares após tratamento odontológico. Quando ocorre a necrose óssea, a LLLT tem sido considerada como uma alternativa de tratamento, melhorando a condição clínica e sintomatológica. Considerações finais: O tratamento dessa necrose óssea é considerado difícil e prolongado. Diante das alterações sistêmicas percebidas com o uso desse medicamento, a odontologia tem buscado tam-bém indicações para o seu uso. Novas linhas de pesquisa têm sido desenvolvidas também em áreas como implantodontia e endodontia, utilizando os BPs como medicamentos de uso tópico.

Dimensional accuracy of select laser sintering and three-dimensional printing biomodels after autoclaving: a preliminary descriptive study / Precisão dimensional da sinterização seletiva a laser e da impressão tridimensional de biomodelos após esterilização em autoclave: um estudo preliminar descritivo

Objective: This is a preliminary descriptive study to evaluate the dimensional accuracy of two biomodels after autoclaving. Materials and methods: Data were obtained using computed tomography (CT) scans of a dry skull, and were used as the basis for the construction of two prototypes using two rapid prototyping techniques: three-dimensional printing (3DP™) with plaster powder; and selective laser sintering (SLS) with polyamide powder. Using 19 cranial landmarks, 10 linear measurements of each prototype were repeated twenty times each using a digital caliper. After that, the SLS and 3DP™ biomodels were autoclaved under the same conditions and technical parameters. Each linear measurement was repeated 20 times after autoclaving, but only for the SLS model because the 3DP™ model deformed during autoclaving. Results and conclusion: The biomodel manufactured with polyamide powder using the SLS technique (SLS model) did not undergo any significant dimensional changes during autoclaving, which suggests that this technique may have potential clinical and surgical applicability.

Objetivo: Este é um estudo preliminar descritivo para avaliar a precisão dimensional de dois biomodelos após aautoclavagem. Materiais e métodos: Os dados foram obtidos por meio de tomografia computadorizada (TC) deum crânio seco, sendo usados como base para a construção de dois protótipos, utilizando duas técnicas de prototipagemrápida: impressão tridimensional (3DP®) com pó de gesso e sinterização seletiva a laser (SLS) de pó depoliamida. Utilizando 19 caracteres cranianos, dez medidas lineares de cada protótipo foram repetidas 20 vezescada uma, utilizando-se um paquímetro digital. Depois disso, os biomodelos de SLS e 3DP® foram autoclavadossob as mesmas condições e parâmetros técnicos. Cada medição linear foi repetida 20 vezes após a autoclavagem,mas apenas para o modelo SLS, pois o modelo 3DP® foi deformado durante a autoclavagem. Resultados e conclusão:Os biomodelos fabricados com pó de poliamida utilizando a técnica SLS (modelo SLS) não sofreram alteraçãodimensional significativa durante a autoclavagem, o que sugere que essa técnica pode ter aplicabilidadeclínica e cirúrgica em potencial.

Dentes retidos: novas perspectivas de localização / Impacted teeth: new diagnostic perspectives

As radiografias convencionais são úteis e fáceis de usar para o diagnóstico de dentes retidos, porém, pela característica de fornecerem imagens bidimensionais e sobrepostas, dificultam o planejamento da cirurgia. O uso da tomografia computadorizada tem se difundido por permitir a visualização de pequenas estruturas anatômicas maxilofaciais relevantes para intervenções cirúrgicas e por possibilitar a visualização das suas relações espaciais em três dimensões. Objetivo e relato dos casos: Relatar os casos de dois pacientes que apresentavam dentes retidos na região anterior da maxila, os quais foram avaliados por tomografia computadorizada. Discutem-se especificidades deste moderno método de diagnóstico por imagem e as vantagens clínicas advindas dessas imagens, pois foi possível identificar a localização precisa dos dentes retidos, a distância das corticais, de acidentes anatômicos e de outros dentes. Considerações finais: A tomografia computadorizada mostrou ser um exame complementar muito importante e preciso para o diagnóstico planejamento cirúrgico e controle pós-operatório de dentes retidos.

Histological and physical analysis of bone neoformation by osteogenesis distraction: A preliminary report.

INTRODUCTION: Osteogenesis distraction (OD) is a mainstream technique in maxillofacial surgical reconstruction with varied applications. OD technique employs a distractor with the aim to get new bone in the site of interest. Osseous maturation time is necessary before the device can be removed and few patients' complaint of related discomfort, especially when these devices are external, and induces superficial infections, paresthesia, hypertrophic scars and social relationship difficulties. The use of Low Level Laser Therapy (LLLT) has been proved beneficial to soft tissue and osseous repairs. MATERIALS AND METHOD: 12 rabbits were randomly divided in to two groups. In all animals, distractor was placed and one group was exposed to LLLT while the other group served as control. After consolidation, animals were sacrificed, the new bone formed were subjected to investigations including histomorphometric, physical analysis and tomographical analysis. Statistical analyses were performed using SPSS software. RESULT: Newly formed bone was significantly different between the groups. The physical properties of the neobone were comparatively better when the animals were exposed to LLLT with varying statistical significance. CONCLUSION: The results obtained with smaller sample size in this study need to be interpreted with care. The results of this preliminary pilot study encourage the use of LLLT during healing period. However the histological, tomographical and physical findings need to be ascertained using a larger sample size to study the bio-stimulatory effects with laser therapy from basics to clinical relevance on wound and bone healing.