In vivo osseointegration evaluation of implants coated with nanostructured hydroxyapatite in low density bone.

OBJECTIVE: This in vivo study, aimed to biomechanically, histomorphometrically and histologically evaluate an implant surface coated with nanostructured hydroxyapatite using the wet chemical process (biomimetic deposition of calcium phosphate coating) when compared to a dual acid-etching surface. MATERIAL AND METHODS: Ten sheep (2-4 years old) received 20 implants, 10 with nanostructured hydroxyapatite coating (HAnano), and 10 with dual acid-etching surface (DAA). The surfaces were characterized with scanning electron microscopy and energy dispersive spectroscopy; insertion torque values and resonance frequency analysis were measured to evaluate the primary stability of the implants. Bone-implant contact (BIC) and bone area fraction occupancy (BAFo) were evaluated 14 and 28 days after implant installation. RESULTS: The HAnano and DAA groups showed no significant difference in insertion torque and resonance frequency analysis. The BIC and BAFo values increased significantly (p<0.05) over the experimental periods in both groups. This event was also observed in BIC value of HAnano group. The HAnano surface showed superior results compared to DAA after 28 days (BAFo, p = 0.007; BIC, p = 0.01). CONCLUSION: The results suggest that the HAnano surface favors bone formation when compared to the DAA surface after 28 days in low-density bone in sheep.

Osseodensification enables bone healing chambers with improved low-density bone site primary stability: an in vivo study.

Primary implant stability is a prerequisite for successful implant osseointegration. The osseodensification technique (OD) is a non-subtractive drilling technique that preserves the bone tissue, increases osteotomy wall density, and improves the primary stability. This study aimed to investigate the hypothesis that OD, through a wider osteotomy, produces healing chambers (HCs) at the implant-bone interface without impacting low-density bone primary stability. Twenty implants (3.5 × 10 mm) with a nanohydroxyapatite (nHA) surface were inserted in the ilium of ten sheep. Implant beds were prepared as follows: (i) 2.7-mm-wide using subtractive conventional drilling (SCD) technique (n = 10); (ii) 3.8-mm-wide using an OD bur system (n = 10). The sheep were randomized to two groups, with samples collected at either 14-(n = 5) or 28-days (n = 5) post-surgery and processed for histological and histomorphometric evaluation of bone-implant contact (BIC) and bone area fraction occupancy (BAFO). No significant group differences were found with respect to final insertion torque and implant stability quotient (p > 0.050). BIC values were higher for SCD after 14 and 28 days (p < 0.050); however, BAFO values were similar (p > 0.050). It was possible to conclude that the OD technique allowed a wider implant bed preparation without prejudice on primary stability and bone remodeling.

Weak evidence for the management of medication-related osteonecrosis of the jaw: An overview of systematic reviews and meta-analyses.

BACKGROUND: Although several therapies are proposed for medication-related osteonecrosis of the jaw (MRONJ), to date there is no consensus or treatment protocol for MRONJ. This overview aims to summarize the available evidence on the management and outcomes of MRONJ. METHODS: An electronic search without language or date restrictions occurred in five databases and gray literature for articles published until March 2020. This overview was performed according to the PICO format. The eligibility criteria comprised systematic reviews (RS) with or without meta-analyses that analyzed treatments outcomes for MRONJ. The methodological quality of each SR was evaluated using AMSTAR 2. RESULTS: Fifteen studies published between 2014 and 2020 were included in this overview. The summary of the evidence showed that conservative treatment and low level laser therapy can yield favorable results for early stages of MRONJ whereas surgical treatment seems to be better for advanced stages. However, qualitative assessment of the SRs highlighted a global low level of quality. CONCLUSIONS: There is weak evidence to support treatment protocols for MRONJ. Because of the low quality of the SRs, highlighted by this overview, no insightful therapeutic recommendations can be issued for any intervention for MRONJ.

In Vivo Biological Evaluation of Orthodontically Moved Incisors after Replantation.

Background and Objectives: There is still considerable controversy regarding the possibility of submitting replanted teeth to orthodontic movement (OM). The purpose of the present study was to evaluate the tissue response after orthodontic movement on replanted teeth. Materials and Methods: Sixty Wistar rats were randomly assigned to four groups (n = 15): G1, replantation without OM after 30 days; G2, replantation with OM after 30 days; G3, replantation without OM after 60 days, and G4, replantation with OM after 60 days. The maxillary left central incisors were extracted and the teeth were stored in milk media. After 30 min, the teeth were replanted and fixed with non-rigid immobilization. All specimens were observed after 30 and 60 days of replantation and then subdivided into two subgroups (with OM or without OM). The animals were euthanized after seven days of the OM started, and the maxillary bone blocks were processed for histological evaluation. Results: The histological results showed periodontal ligament repair in both periods studied without OM; however, ankylosis and root resorption was seen in all orthodontically moved teeth. Conclusions: The orthodontic movement did not favor tissue response in all replanted teeth, regardless of the experimental periods.

Determination of TNF-a Gene Polymorphisms on Skeletal Pattern in Class II Malocclusion.

Bone development and growth is a non-going, life-long process, varying greatly among individuals and much of this variation could be modulated by genetic factors. The purpose of this study was to evaluate the association between the polymorphisms in the TNF-a gene and skeletal class II malocclusion. Single nucleotide polymorphisms in TNF-a (rs1799724; rs1800629) gene were studied in 79 skeletal class II malocclusion and 102 skeletal class I malocclusion subjects from Straight Wire Group of Studies on Orthodontics and Functional Orthopedics for Maxillary from Rio de Janeiro, Brazil. The Genotyping of these selected polymorphisms was carried out by TaqMan real-time PCR using genomic DNA extracted from buccal cells. All allele and genotype frequencies were compared between the groups using the PLINK® software in a free, in a dominant and in a recessive model using a chi-square test (p≤0.05). There was no significant association of TNF-a (rs1799724; rs1800629) genotype and allele distribution with skeletal class II malocclusion. Regardless of the dominant or recessive genetic model, the preferential genotype associations for rs1799724 and rs1800629 was insignificant. In conclusion, no evidence of association is apparent between genetic polymorphisms involving TNF-a and skeletal class II malocclusion or the position of the maxilla and mandible in the postero-anterior direction.

Determination of tnf-a gene polymorphisms on skeletal pattern in class ii malocclusion

Abstract Bone development and growth is a non-going, life-long process, varying greatly among individuals and much of this variation could be modulated by genetic factors. The purpose of this study was to evaluate the association between the polymorphisms in the TNF-a gene and skeletal class II malocclusion. Single nucleotide polymorphisms in TNF-a (rs1799724; rs1800629) gene were studied in 79 skeletal class II malocclusion and 102 skeletal class I malocclusion subjects from Straight Wire Group of Studies on Orthodontics and Functional Orthopedics for Maxillary from Rio de Janeiro, Brazil. The Genotyping of these selected polymorphisms was carried out by TaqMan real-time PCR using genomic DNA extracted from buccal cells. All allele and genotype frequencies were compared between the groups using the PLINK® software in a free, in a dominant and in a recessive model using a chi-square test (p≤0.05). There was no significant association of TNF-a (rs1799724; rs1800629) genotype and allele distribution with skeletal class II malocclusion. Regardless of the dominant or recessive genetic model, the preferential genotype associations for rs1799724 and rs1800629 was insignificant. In conclusion, no evidence of association is apparent between genetic polymorphisms involving TNF-a and skeletal class II malocclusion or the position of the maxilla and mandible in the postero-anterior direction.

Resumo O desenvolvimento e crescimento ósseo é um processo contínuo, que dura toda a vida, variando muito entre os indivíduos e grande parte dessa variação pode ser modulada por fatores genéticos. O objetivo deste estudo foi avaliar a associação entre os polimorfismos no gene TNF-a e a má oclusão da classe II esquelética. Polimorfismos no gene TNF-a (rs1799724; rs1800629) foram estudados em 79 indivíduos com má oclusão esquelética de classe II e 102 indivíduos com má oclusão esquelética classe I do Grupo de Estudos em Ortodontia e Ortopedia Funcional dos Maxilares do Rio de Janeiro, Brasil. A genotipagem destes polimorfismos foi realizada por PCR em tempo real, através de DNA genômico extraído de células bucais. Todas as frequências alélicas e genotípicas foram comparadas entre os grupos utilizando o software PLINK® em um modelo livre, dominante e recessivo. Foi aplicado o teste do qui-quadrado (p≤0,05). Não houve associação significativa na distribuição genotipica e alélica do gene TNF-a (rs1799724; rs1800629) com a má oclusão de classe II esquelética. Independentemente do modelo genético dominante ou recessivo, as associações genotípicas preferenciais para rs1799724 e rs1800629 foram insignificantes. Pode-se concluir que, não existe evidência de associação entre polimorfismos genéticos envolvendo TNF-a e má oclusão esquelética de classe II ou a posição da maxila e mandíbula na direção póstero-anterior.

Association between asthma and periodontal disease: A systematic review and meta-analysis.

BACKGROUND: The aim of this systematic review (SR) is to evaluate the association between asthma and periodontal disease. METHODS: An electronic search without date or language restrictions was carried out in PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, and LILACS until May 2016. In addition, manual searches and searches of the gray literature were conducted. The search process, data analysis, and quality assessment were performed by two independent reviewing authors. Eligibility criteria included prospective and retrospective cohort studies, case-controls, and randomized clinical trials. RESULTS: The search and selection process yielded 21 studies, published between 1979 and 2017. The meta-analysis showed a statistically significant difference for the parameters of gingival bleeding, plaque index, and gingival index for participants with asthma (P < 0.001). CONCLUSION: Data from this SR strongly suggest the association of asthma with periodontal disease.

Accelerated Healing Period with Hydrophilic Implant Placed in Sheep Tibia.

The objective of this study was to evaluate the early osseointegration of two different implants surfaces, a sandblasted and acid-etched surface (TN) compared with same geometry and surface roughness modified to be hydrophilic/wettable by conditioning in an isotonic solution of 0.9% sodium-chloride (TA) through histological and histomorphometric analysis after sheep tibia implantation. Forty dental implants, divided in two groups (TN and TA) were placed in the left tibia of twenty healthy, skeletally mature Santa Ines sheep (n=5/experimental period). After 7, 14, 21 and 28 days post-implantation, the samples were removed and the sheep were kept alive. Analysis of resin sections (30 µm) allowed the quantification of bone area (BA) and bone-to-implant contact (BIC). TA group presented nearly 50% increase in BA at 14 days (p<0.001, ANOVA - Tukey's post test) compared with 7 days. The TA presented higher values than the TN for BA and BIC at 14, 21, and 28 days after placement, stabilizing bone healing. TA hydrophilic surface promoted early osseointegration at 14 and 21 days compared to TN, accelerating bone healing period post-implant placement in sheep tibia.

Accelerated Healing Period with Hydrophilic Implant Placed in Sheep Tibia

Abstract The objective of this study was to evaluate the early osseointegration of two different implants surfaces, a sandblasted and acid-etched surface (TN) compared with same geometry and surface roughness modified to be hydrophilic/wettable by conditioning in an isotonic solution of 0.9% sodium-chloride (TA) through histological and histomorphometric analysis after sheep tibia implantation. Forty dental implants, divided in two groups (TN and TA) were placed in the left tibia of twenty healthy, skeletally mature Santa Ines sheep (n=5/experimental period). After 7, 14, 21 and 28 days post-implantation, the samples were removed and the sheep were kept alive. Analysis of resin sections (30 μm) allowed the quantification of bone area (BA) and bone-to-implant contact (BIC). TA group presented nearly 50% increase in BA at 14 days (p<0.001, ANOVA - Tukey's post test) compared with 7 days. The TA presented higher values than the TN for BA and BIC at 14, 21, and 28 days after placement, stabilizing bone healing. TA hydrophilic surface promoted early osseointegration at 14 and 21 days compared to TN, accelerating bone healing period post-implant placement in sheep tibia.

Resumo O objetivo deste estudo foi avaliar a osseointegração precoce de duas superficies diferentes de implantes, uma superfície tratada com jateamento e ataque ácido (TN) comparada com outra superfície com a mesma geometria e rugosidade e modificada com hidrofilicidade / molhabilidade através do condicionamento em solução isotônica de 0,9% de cloreto de sódio (TA) através de análises histológica e histomorfométrica após a implantação em tíbia de ovelhas. Quarenta implantes dentários, divididos em dois grupos (TN e TA), foram implantados na tíbia esquerda de vinte ovelhas Santa Inês (n=5/período experimental) saudáveis e esqueleticamente maduras. Após 7, 14, 21 e 28 dias pós-implantação, as amostras foram coletadas e as ovelhas foram mantidas vivas. A análise dos cortes em resina (30 μm) permitiu a quantificação da área de osso (BA) e do contato osso-implante (BIC). O grupo TA apresentou aumento de quase 50% na BA aos 14 dias (p <0,001, ANOVA - pós teste de Tukey) em comparação com 7 dias. O grupo TA apresentou valores maiores do que o TN para BA e BIC aos 14, 21 e 28 dias após a implantação, estabilizando a cicatrização óssea. A superfície hidrofílica TA promoveu uma osseointegração precoce aos 14 e 21 dias em relação à TN, acelerando o período de cicatrização óssea após a instalação dos implantes em tíbias de ovelha.

Physico-chemical and Histomorphometric Evaluation of Zinc-containing Hydroxyapatite in Rabbits Calvaria.

The aim of this study was to characterize the physico-chemical properties and bone repair after implantation of zinc-containing nanostructured porous hydroxyapatite scaffold (nZnHA) in rabbits' calvaria. nZnHA powder containing 2% wt/wt zinc and stoichiometric nanostructured porous hydroxyapatite (nHA - control group) were shaped into disc (8 mm) and calcined at 550 °C. Two surgical defects were created in the calvaria of six rabbits (nZnHA and nHA). After 12 weeks, the animals were euthanized and the grafted area was removed, fixed in 10% formalin with 0.1 M phosphate buffered saline and embedded in paraffin (n=10) for histomorphometric evaluation. In addition, one sample from each group (n=2) was embedded in methylmethacrylate for the SEM and EDS analyses. The thermal treatment transformed the nZnHA disc into a biphasic implant composed of Zn-containing HA and Zn-containing ß-tricalcium phosphate (ZnHA/ßZnTCP). The XRD patterns for the nHA disc were highly crystalline compared to the ZnHA disc. Histological analysis revealed that both materials were biologically compatible and promoted osteoconduction. X-ray fluorescence and MEV-EDS of nZnHA confirmed zinc in the samples. Histomorphometric evaluation revealed the presence of new bone formation in both frameworks but without statistically significant differences (p>0.05), based on the Wilcoxon test. The current study confirmed that both biomaterials improve bone repair, are biocompatible and osteoconductive, and that zinc (2wt%) did not increase the bone repair. Additional in vivo studies are required to investigate the effect of doping hydroxyapatite with a higher Zn concentration.

Physico-chemical and Histomorphometric Evaluation of Zinc-containing Hydroxyapatite in Rabbits Calvaria

Abstract The aim of this study was to characterize the physico-chemical properties and bone repair after implantation of zinc-containing nanostructured porous hydroxyapatite scaffold (nZnHA) in rabbits' calvaria. nZnHA powder containing 2% wt/wt zinc and stoichiometric nanostructured porous hydroxyapatite (nHA - control group) were shaped into disc (8 mm) and calcined at 550 °C. Two surgical defects were created in the calvaria of six rabbits (nZnHA and nHA). After 12 weeks, the animals were euthanized and the grafted area was removed, fixed in 10% formalin with 0.1 M phosphate buffered saline and embedded in paraffin (n=10) for histomorphometric evaluation. In addition, one sample from each group (n=2) was embedded in methylmethacrylate for the SEM and EDS analyses. The thermal treatment transformed the nZnHA disc into a biphasic implant composed of Zn-containing HA and Zn-containing β-tricalcium phosphate (ZnHA/βZnTCP). The XRD patterns for the nHA disc were highly crystalline compared to the ZnHA disc. Histological analysis revealed that both materials were biologically compatible and promoted osteoconduction. X-ray fluorescence and MEV-EDS of nZnHA confirmed zinc in the samples. Histomorphometric evaluation revealed the presence of new bone formation in both frameworks but without statistically significant differences (p>0.05), based on the Wilcoxon test. The current study confirmed that both biomaterials improve bone repair, are biocompatible and osteoconductive, and that zinc (2wt%) did not increase the bone repair. Additional in vivo studies are required to investigate the effect of doping hydroxyapatite with a higher Zn concentration.

Resumo O objetivo deste estudo foi caracterizar físico-químicamente e avaliar o reparo ósseo de discos de hidroxiapatita porosa contendo zinco após a implantação em calvária de coelhos (nZnHA). O pó de nZnHA e o pó hidroxiapatita porosa estequiométrica nanoestruturada (controle - nHA) foram confeccionados em discos (8 mm) e calcinados a 550˚C. Dois defeitos cirúrgicos foram criados na calvária de seis coelhos para a implantação dos discos. Após 12 semanas, os animais foram eutanasiados e as áreas enxertadas foram removidas, fixadas em formol a 10% e embebidas em parafina (n=10) para avaliação histomorfométrica. Além disso, uma amostra de cada grupo (n=2) foi embebida em metilmetacrilato para análise de MEV e EDS. O tratamento térmico dos discos de nZnHA transformou-os em implantes bifásicos compostos por HA contendo Zinco e β fosfato tricálcico com Zinco (ZnHA/βZnTCP). Os discos de nHA, apresentaram-se altamente cristalinos e com baixa solubilidade quando comparados aos discos de ZnHA. A análise histológica revelou que ambos os materiais foram biologicamente compatíveis e promoveram a osteocondução. As análises de FRX e MEV-EDS confirmaram a presença do zinco nas amostras de nZnHA. A avaliação histomorfométrica revelou a presença de neoformação óssea em ambos os grupos, porém sem diferenças estatísticas entre eles, com base no teste de Wilcoxon (p>0,05). O presente estudo confirmou que ambos os biomateriais otimizaram o reparo ósseo, foram biocompatíveis e osseocondutivos e a presença do zinco não favoreceu o reparo ósseo. Estudos adicionais in vivo devem ser conduzidos a fim de investigar o efeito de maiores concentrações de zinco.

Increased overjet is a risk factor for dental trauma in preschool children.

CONTEXT: Traumatic dental injury and malocclusion constitute a public health problem due to their high prevalence. Preventing or detecting such conditions, in any population, is of paramount importance. AIM: Assessing the association of anterior occlusal characteristics and dental trauma in preschool children. SETTINGS AND DESIGN: A cross-sectional study was carried out with 2-6-year-old randomly selected by a sample calculation, resulting in 606 subjects MATERIALS AND METHODS: A questionnaire to collect information about the sample (age, gender, and race) was sent to the children's parents. Two trained and calibrated examiners (Kappa 0.80) evaluated dental trauma according to criteria established by the World Health Organization. The following anterior occlusal characteristics were evaluated: Normal occlusion, anterior open bite, anterior crossbite, increased overjet (categorized as ≥3 mm), and increased overbite (categorized as ≥3 mm). STATISTICAL ANALYSIS USED: The variables associations were assessed (odds ratio, Chi-square test, and logistic regression, P < 0.05) using statistical software (SPSS, version 16.0). RESULTS: Dental trauma was observed in 20.8% and malocclusion in 48.6% of the children. There is an association between malocclusion and dental trauma (P = 0.01). Children with malocclusion have a 64% higher chance of suffering dental trauma. Increased overjet was the type of malocclusion related to a higher rate of tooth fracture (P < 0.01). Subjects with this type of malocclusion suffered tooth fractures three times more often than subjects with other malocclusion types. CONCLUSIONS: There was association of dental trauma and malocclusion. Increased overjet was the most common malocclusion related to dental trauma. Preventive strategies are needed to reduce the rate of anterior malocclusion and, consequently, dental trauma in preschool children.

Effect of a metal primer on the adhesive interface between composite and lingual brackets.

AIM: To test the null hypothesis was that there is no difference in the shear strength of indirectly bonded lingual brackets with or without prior application of metal primer on their bases. MATERIALS AND METHODS: Forty recently extracted human premolars were obtained and randomly divided into two groups of 20 each: group I (control), phosphoric acid and indirect bonding with Maximum Cure (Reliance Orthodontic Products, Itasca, IL, USA); and group II, application of metal primer (Metal Primer, Reliance Orthodontic Products) on bracket base prior to conditioning and indirect bonding. All products were used according to the manufacturer's instructions. A universal testing machine was used to apply a shear force directly onto the enamel- bracket interface at a speed of 1.0 mm/min. RESULTS: Mean (SD) shear bond strength for group I was 12.87 (5.75) MPa and for the group II was 18.47 (8.48) MPa. The Student's t-test showed a significant difference (p = 0.0311) between the groups. The chi-square test for the adhesive remnant index (ARI) indicated that there was a significant difference (p = 0.2750). CONCLUSION: The application of metal primer increased the adhesion of lingual brackets, and may be a promising procedure for clinical orthodontics.

Avaliação multiparamétrica da citotoxicidade in vitro de um fio ortodôntico à base de resina polimérica reforçada com fibra de vidro / Multiparametric cytotoxicity in vitro evaluation of a glass fiber-reinforced composite orthodontic archwire

O objetivo deste trabalho é avaliar a citotoxicidade dos fios ortodônticos estéticos feitos à base de resina polimérica reforçada com fibras de vidro, por três diferentes parâmetros de viabilidade celular. Foram preparados, de acordo com normas internacionais, extratos de amostras do fio Optis® Preformed Archwire intactos ou multiseccionados (em seções de 10 mm) e, como referência, fios de aço inoxidável do mesmo fabricante. Fenol a 2% e poliestireno denso foram utilizados como controle negativo e positivo respectivamente. Células de fibroblastos de camundongo da linhagem Balb/c-3T3 foram expostas por 24 horas a esses extratos, e a viabilidade celular foi identificada por três parâmetros: atividade mitocondrial, a partir do método do XTT, integridade membranar, pela captação do corante vermelho neutro e densidade celular, por meio do teste de exclusão do corante cristal violeta. Os extratos dos fios (aço inoxidável e fio em resina reforçada por fibra de vidro) foram compatíveis com altos índices de viabilidade celular medido através dos três diferentes parâmetros, sem diferenças estatísticas significativas entre os grupos. O processamento do fio estético em pequenas secções não alterou sua biocompatibilidade medida pelos mesmos métodos, indicando não haver diferença de toxicidade entre sua face externa de resina e seu interior reforçado em fibra de vidro. De acordo com os parâmetros avaliados, o fio estético não apresentou citotoxicidade, similar ao aço inoxidável já em largo uso ortodôntico. No entanto, novos parâmetros devem ser investigados para validá-lo, tanto com relação a aspectos biológicos como a aspectos físicos mais relacionados à sua eficiência na ortodontia.

The purpose of this paper is evaluate the cytotoxicity of orthodontic archwires on polymeric resin reinforced with glass fiber, by three different cell viability parameters. According to international standards, extract samples of Optis® Preformed Archwire, both intact and sectioned into 10 mm pieces and, as reference, of stainless steel archwires, form the same manufacturer. 2% phenol and dense polystyrene were employed as a positive and negative control respectively. Balb/c-3T3 mouse fibroblasts were exposed by 24 hours to the extracts and cell viability was assayed by three parameters: mitochondrial activity (XTT), membrane integrity, measured by Neutral red uptake, and cell density as measured by the Violet Crystal dye exclusion test. Both archwires (stainless steel and fiber glass reinforced resin) were consisted with high levels of cell viability as measured by the three tests, without significative statistical differences among groups. Wire processing by cutting into little sections did not change biocompatibility as measured by the same methods, suggesting that there is no difference between the resin external face and the internal glass fiber reinforced interior. According to the evaluated parameters, the esthetic archwire does not presented cytotoxicity levels, similar to those obtained with a material widely employed in orthodontics. However, other parameters should be investigated in order to validate this material, both related to biological aspects, as well as physical characteristics more associated to its efficacy in orthodontics.

Avaliação da citotoxicidade in vitro de elásticos ortodônticos com tratamento de superfície / Citotoxicity evaluation in vitro of orthodontic elastics showing superficial treatment

Este trabalho investigou a citotoxicidade de elásticos ortodônticos com tratamento de superfície da marca Super Slick da TP Orthodontics, utilizando ensaio de citotoxicidade em culturas de células. Os resultados foram avaliados pelo índice do tamanho do halo de difusão e pelo índice de lise celular, sendo verificada a existência de um halo de difusão ao redor da amostra não maior que 0,5cm em extensão a partir dessa, indicando que houve difusão de substâncias para o ágar, porém, sem a presença de lise celular, ou seja, não houve ação tóxica capaz de lisar as células. Com base nos resultados encontrados, através da metodologia utilizada, concluiu-se que o elástico com tratamento de superfície, testado neste trabalho, apresenta biocompatibilidade. No entanto, considerando as poucas informações sobre o polímero utilizado no tratamento do elástico, mais pesquisas devem ser realizadas para melhor compreensão dos resultados obtidos.

Orthodontic movement in traumatically intruded teeth: a case report.

Intrusive luxation of permanent mature teeth is one of the most serious injuries to the periodontal ligament in dental traumatology. Various treatment approaches are currently practised. The treatment of choice for traumatically intruded teeth was to combine orthodontic repositioning and endodontic treatment. This case report describes the treatment of a 50-year-old male patient, with four completely intruded mature permanent maxillary incisors. Orthodontic extrusion was initiated 1 week after the trauma. After 10 days, the crowns of the teeth were exposed to start endodontic therapy. Nine weeks after the injury and 8 weeks after the beginning of orthodontic extrusion, the intruded incisors were back about to their original position before the displacement occurred. All treatment management as well as a follow-up 8 years after the trauma are described.