Influence of ceramic crown design (translucent monolithic zirconia vs. bilayered) of implant-supported single crowns after mechanical cycling.

OBJECTIVES: This study aimed to assess the influence of translucent monolithic versus bilayered crowns and whether the use of a CoCr base abutments affects the fatigue and fracture resistance of screwed implant-supported single crowns with external connections under mechanical cycling. MATERIALS AND METHODS: Fifty specimens were divided into groups: (1) metal-ceramic (MC) crown, (2) veneered zirconia crown (Zr), (3) veneered zirconia crown with a CoCr base abutment (ZrB), (4) monolithic translucent zirconia crown (MZr), and (5) monolithic translucent zirconia crown with a CoCr base abutment (MZrB). Specimens underwent mechanical cycling (5 × 106 cycles; 150 N) evaluating fatigue resistance (number of failures) and those that failed were subsequently subjected to fractographic analyses (stereomicroscope and scanning electron microscope) to evaluate failure location and area, and maximum fracture load was also measured. RESULTS: The failure-related survival rate (100%) and maximum fracture resistance of the MZrB were significantly higher than those of MC and Zr (50%; p < 0.05). There were no significant differences in the failure rate and fracture resistance when a CoCr base abutment was used or not in the translucent monolithic Zr groups (p > 0.05;MZrB vs. MZr). Failure location, with MC crowns' fractures, noted at the screw area (p = 0.043), while all-ceramic crowns were mostly in the cuspid and to failure area, the Zr group had the largest mean (15.55 ± 9.17 mm2) among the groups, significant difference only when compared with MC (1.62 ± 0.81 mm2) (p = 0.025). CONCLUSIONS: Translucent monolithic zirconia crowns exhibited significantly higher fatigue and fracture resistance compared with conventional MC and bilayered crowns. CLINICAL SIGNIFICANCE: The appropriate choice of material and manufacturing technique is crucial for predicting the higher clinical performance of single crowns. Enhanced mechanical resistance in terms of fatigue and fracture resistance can be achieved by replacing MC and bilayered restorations with computer-aided design and computer-aided manufacturing monolithic zirconia.

Mechanical properties of polymethyl methacrylate as a denture base: Conventional versus CAD-CAM resin - A systematic review and meta-analysis of in vitro studies.

STATEMENT OF PROBLEM: The development of polymethyl methacrylate (PMMA) computer-aided design and computer-aided manufacturing (CAD-CAM) resin blocks with reported improved mechanical properties has simplified complete denture production. However, whether the objective of improved mechanical properties has been achieved compared with conventional heat-polymerized PMMA is not yet clear. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the mechanical properties of denture base resins manufactured by conventional heat-polymerization and by CAD-CAM in terms of flexural strength, flexural modulus, and surface roughness. MATERIAL AND METHODS: Electronic databases (PubMed/MEDLINE, Scopus, Web of Science) were independently searched by 2 researchers for relevant studies published up to November 2020. The population, intervention, comparison, and outcome (PICO) question was, "Does the conventionally manufactured, heat-polymerized PMMA resin, as a denture base, demonstrate the same mechanical properties as the CAD-CAM resin block?" In addition, a meta-analysis was based on the inverse variance method. Flexural strength, flexural modulus, and surface roughness were analyzed through the continuous outcome evaluated by mean difference and standard deviation, with 95% confidence intervals. To evaluated heterogeneity, the I2 value (≤25%=low, ≥50%=moderate and ≥75%=high) and the P value were considered. P<.10 indicated statistical difference for heterogeneity. The effects of meta-analysis were based on the results of heterogeneity as per the studies. RESULTS: Thirteen in vitro studies were included in the analysis. A total of 507 specimens were evaluated, 222 conventional and 285 CAD-CAM. In terms of flexural strength, the data showed no significant difference when conventional heat-polymerized PMMA was compared with CAD-CAM PMMA resins (P=.06; mean difference=18.28; 95% confidence interval:-0.42 to 36.97). In terms of flexural modulus, there was a significant difference for the CAD-CAM PMMA group (P=.01; mean difference=589.22; 95% confidence interval: 117.95 to 1060.48). In terms of surface roughness, a significant difference was observed between the groups (P=.02; mean difference=-0.53; 95% confidence interval: -0.97 to -0.09) with the conventional heat-polymerized PMMA resin having higher surface roughness values. CONCLUSIONS: The mechanical properties of CAD-CAM PMMA resins were generally improved when compared with heat-polymerized polymethyl methacrylate resin.

A clinical comparison of 1-piece versus 2-piece implants: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: One-step dental implant surgery with a 1-piece implant has been introduced with the aim of simplifying and increasing the effectiveness of treatment and providing greater comfort for the patient. Whether these goals have been met compared with conventional 2-piece implants remains unclear. PURPOSE: The purpose of this systematic review and meta-analysis was to compare the use of 1-piece versus 2-piece implants in terms of marginal bone loss and implant survival rate. MATERIAL AND METHODS: This systematic review and meta-analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was recorded in the International prospective register of systematic reviews (PROSPERO) database (CRD 42018095721). A literature search was conducted in the PubMed/MEDLINE, Web of Science, and Cochrane Library databases for articles published up to May 2018. The population, intervention, comparison, outcome (PICO) question was, "Do patients who received 1-piece implants show similar marginal bone loss, survival rates, and complications as those who receive 2-piece implants?" RESULTS: The meta-analysis was based on the Mantel-Haenszel and inverse variance methods. Implant survival rate was analyzed by using a dichotomous outcome, measured according to risk ratio (RR) and marginal bone loss by continuously evaluating the outcomes according to the mean difference (MD), both with a corresponding 95% confidence interval (CI). Five studies, including 270 participants with a mean age of 54.70 years and receiving 434 dental implants, were included. The mean follow-up period was 4 years. Meta-analysis did not reveal a significant difference in relation to implant survival rate (P=.85; RR: -0.89; CI: -0.27 to 2.98), as well as to marginal bone loss (P=.85; MD: -0.43; CI: -0.43 to -0.52). CONCLUSIONS: One- and 2-piece implants demonstrated effectiveness in the rehabilitation of patients requiring dental implants.

Analysis of the effects of irradiation in osseointegrated dental implants.

OBJECTIVE: The purpose of the present study was to evaluate the influence of radiation in osseointegrated dental implants installed in tibiae of rats. MATERIAL AND METHODS: Screw-shaped implants (2.5 mm diameter by 3.5 mm length) were custom made from commercially pure titanium bars. Titanium implants were blasted and sterilized before implantation. Animals were divided into two groups of 12 animals each and the rats were not paired after the groups' formation. The experimental group (group 1) received external irradiation 4 weeks after surgery while in the control group (group 2) animals were kept free of radiation. The shear strength required to detach the implant from bone was measured by push-out testing and osseointegration was histologically evaluated. RESULTS: Results showed that the compressive strength of irradiated implants (33.49 MPa) was significantly lower than the compressive strength of non-irradiated implants (48.05 MPa). CONCLUSIONS: We concluded that the mechanical strength bonding between implants and host tissues decreased after irradiation.

Photoelastic stress analysis of different attachment systems on implant-retained and conventional palatal obturator prostheses.

BACKGROUND: Considering that an increasing number of patients are victims of mutilator surgical resections, these studies are important for treatment success of rehabilitation of patients presenting oronasal communication. PURPOSE: The aim of this study was to assess the stress distribution through photoelasticity in palatal obturator prostheses with different attachment systems for implants. METHODS: Two photoelastic models were obtained from an experimental maxillary model presenting an oronasal communication. One model was fabricated without implant, and the other with 2 implants 10 mm in length inserted in the left crest. Four colorless palatal obturator prostheses were fabricated. One prosthesis presented no attachment system, whereas the remaining prostheses were adapted to 3 attachment systems. The assembly was positioned in a circular polariscope for application of axial load. RESULTS: The results were based on photographic records of stress in the photoelastic model submitted to loading. The records revealed higher stress concentration on the bar-clip system followed by the O'ring/bar-clip and O'ring systems, respectively. A homogeneous stress distribution was observed on the photoelastic model with the mucous-supported prosthesis. CONCLUSIONS: The attachment systems generated different characteristics of stress distribution that was concentrated surrounding the implants. The bar-clip system exhibited the highest stress concentration on the alveolar crest.

Photoelastic stress analysis in screwed and cemented implant-supported dentures with external hexagon implants.

The aim of this study was to assess the stress distribution of the retention systems (screwed and cemented) for implant-supported fixed partial dentures by means of photoelastic method. Two models were made of photoelastic resin PL-2 with 2 implants (phi = 4.00 x 10 mm) located in the second premolar and molar region in each photoelastic model, varying the retention system (screwed and cemented). The implant-supported fixed partial dentures were standardized and made of Ni-Cr alloy. Axial and oblique (45 degrees) forces of 100 N were applied on the occlusal surface by means of a Universal Testing Machine (EMIC-DL 3000; São José dos Pinhais, Paraná, Brazil). The results were observed and photographed in the field of a circular polariscope and qualitatively analyzed with the aid of computer software (Adobe Photoshop, San Jose, CA). The screw retention system presented the highest number of fringes when the loads were applied on the premolar, pontic, and molar and showed this behavior in all load applications, under axial and oblique loads. It was concluded that there was a better stress distribution and lower magnitude of stress on the cemented implant-supported dentures, under axial and oblique loads. Oblique load caused an increase in stress concentrations in all the models.

Effects of thermocycling on mechanical properties of soft lining materials.

UNLABELLED: Soft linings are materials used to reduce the tension and forces of mastication, forming all or part of the fitting surface of a denture. This study evaluated the effect of thermocycling on water absorption, solubility, Shore A hardness and color stability of permanent soft liner materials. MATERIAL AND METHODS: Two chemically activated soft liner materials (Sofreliner S; GC Reline Ultrasoft) were tested. Twenty cylindrical specimens (30.0 x 1.0 mm) were prepared for measuring water absorption and solubility and another twenty (30.0 x 3 mm) for analyzing Shore A hardness and color stability. Color was measured by a spectrophotometer before and after 2000 thermocycles. A one-way ANOVA test and Tukey test at a 5% confidence level (p<0.05) were performed. RESULTS: The results did not show statistical differences for water absorption, solubility or color stability. The post-thermocycling Shore A hardness values were significantly higher than those before the treatment. CONCLUSION: Thermocycling of soft liner materials increased Shore A hardness.

Effect of commercial mouthwashes on the corrosion resistance of Ti-10Mo experimental alloy.

The purpose of this work was to evaluate the effect of three commercial mouthwashes on the corrosion resistance of Ti-10Mo experimental alloy. Experiments were made at 37.0 +/- 0.5 degrees C in a conventional three-compartment double wall glass cell containing commercial mouthwashes. Three mouthwashes with different active ingredients were tested: (I) 0.05% sodium fluoride + 0.03% triclosan; (II) 0.5 g/l cetylpyridinium chloride + 0.05% sodium fluoride; (III) 0.12% chlorohexidine digluconate. The assessment of the individual effect of active ingredients was studied by using 0.05% sodium fluoride. Commercially pure titanium (CP Ti) was used as control. Microstructures from Ti-10Mo experimental alloy and CP Ti were also evaluated using optical microscopy. Ti-10Mo as-cast alloy shows the typical rapidly cooled dendrites microstructure (beta phase) while CP Ti has exhibited a metastable martensitic microstructure. Electrochemical behavior of dental materials here studied was more affected by mouthwash type than by Ti alloy composition or microstructure. In both alloys passivation phenomenon was observed. This process may be mainly related to Ti oxides or other Ti species present in spontaneously formed film. Small differences in passive current densities values may be connected with changes in film porosity and thickness. Protective characteristics of this passive film are lower in 0.05% sodium fluoride + 0.03% triclosan mouthwash than in the other two mouthwashes tested.

Estratégias de sustentabilidade na prática odontológica / Sustainability strategies in dental practice

Cirurgiões-Dentistas têm discutido amplamente a questão ambiental com vistas à implementação de estratégias de sustentabilidade na prática odontológica. É inaceitável o exercício da Odontologia na atualidade como tão somente a solução de problemas bucais. O Odontólogo tem a responsabilidade social de incorporar em seu cotidiano profissional atitudes concretas que reduzam o impacto de seu processo produtivo. O propósito deste trabalho é caracterizar o desenvolvimento e a aplicação de modelo de atuação voltado para a responsabilidade social no uso eficiente de energia elétrica na prática odontológica, incorporado à preservação da causa ambiental na Odontologia, no sentido de traçar cenário de mudança que permita a gestão ambiental sem comprometimento da qualidade dos serviços oferecidos

Dentists have widely discussed environmental issues with a view to the implementation of sustainability strategies in dental practice. It is unacceptable the practice of dentistry today as merely the solution of dental problems. The Dentist has a social responsibility to incorporate into your daily work concrete actions to reduce the impact of its production process. The purpose of this study is to characterize the development and application of performanceoriented model of social responsibility in dental practice, built to preserve the environmental cause in dentistry in order to trace change scenario that allows the environmental management without compromising the quality of services offered

Effects of Tissucol and epsilon aminocaproic acid in the healing process following dental extraction in dehydrated rats.

A histological study was conducted of the alveolar bone healing process following tooth extraction of dehydrated rats after the implantation of fibrin adhesive (TISSUCOL) associated to previous irrigation of the wound with a 5% epsilon aminocaproic acid solution (EACA). Seventy two rats were used, divided into three groups receiving different treatments after the surgical procedure. In group I, the gingival mucosa was sutured after extraction of the right upper incisor. In groups II and III, chronic dehydration was produced by water deprivation for 9 days (3 days in the preoperative period and 6 days in the postoperative period). In the animals of Group II, after tooth extraction, the gingival mucosa was sutured in the same way as performed in group I. In group III, after extraction, the dental socket was irrigated with 5% EACA, followed by implantation of the fibrin adhesive (TISSUCOL). The mucosa was sutured in the same way as performed in the other groups. At 3, 7, 15 and 21 postoperative days, the animals were sacrificed in number of 6 for each group. Specimens containing the dental socket were removed and fixed in 10% formalin and decalcified in an equal part formic acid and sodium citrate solution. After routine processing, the specimens were embedded in paraffin for microtomy. We obtained 6 microm semi-serial slices that were stained with hematoxylin and eosin for histological evaluation. The results showed that the water deprivation in the pre- and postoperative periods caused a delay in the alveolar bone healing process. The use of the fibrin adhesive (TISSUCOL) produced an improvement in the fibrinolytic picture caused by dehydration.

Tratamento de superfície de implantes dentários: SBF / Surface treatment of dental implants: SBF

Diversos tratamentos da superfície dos implantes dentários têm sido desenvolvidos com o objetivo de garantir ancoragem ao tecido ósseo, otimização dos determinantes de estrutura eletrônica, cristalinidade, composição e propriedades. As técnicas de recobrimento têm sido propostas com o objetivo de criar união bioquímica capaz de acelerar as fases iniciais de formação do tecido ósseo, aliando as propriedades positivas do titânio e suas ligas à bioatividade dos materiais cerâmicos. Este trabalho aborda protocolo de manipulação do SBF para recobrimento de ligas de titânio. A obtenção do recobrimento com nucleação de apatita ocorre por imersão do substrato em solução sintética que simula o plasma sanguíneo (Simulated Body Fluid). O protocolo de manipulação da solução SBF permite estabelecer diretrizes racionalizadas quanto ao uso e organizadas de modo a tornar prática sua aplicação

Various surface treatments of dental implants have been developed in order to ensure anchorage to bone tissue, optimization of the determinants of electronic structure, crystallinity, composition and properties. Coating techniques have been proposed in order to create union biochemical able to accelerate the early stages of bone tissue, combining the positive properties of titanium and its alloys bioactivity of ceramic materials. This paper discusses protocol for handling the SBF coating of titanium alloys. The apatite phase nucleation occurs by immersing the substrate in synthetic solution simulating blood plasma (Simulated Body Fluid). The protocol allows manipulation of the SBF solution to establish guidelines regarding the use streamlined and organized to make practical application

Association between bruxism, alcoholand tobacco use among brazilian students / Relação entre bruxismo e consumo de álcool e tabaco em estudantes brasileiros

Diferentes fatores que afetam o sistema nervoso central são considerados de risco para o bruxismo. Universitários não são imunes ao bruxismo, consumo de álcool e uso de tabaco apesar de sua formação e responsabilidade social. Avaliou-se a associação entre bruxismo, consumo de álcool e tabaco entre graduandos de Odontologia. Foram voluntários 180 estudantes (17-29 anos) da Faculdade de Odontologia de Araçatuba/ UNESP, divididos entre aqueles com e sem bruxismo, com base em critérios clínicos validados realizados por quatro examinadores com luz natural e espátula de madeira. Bruxismo foi registrado nas seguintes categorias: sem facetas de desgaste; facetas no esmalte; facetas na dentina; facetas em metade da coroa e facetas em mais de 2/ 3 da coroa. Auto-questionário validado para o consumo de álcool e tabaco, com 29 perguntas foi respondido pelos dois grupos. Teste T e Exato de Fischer foram aplicados. Bruxismo foi mais frequente entre tabagistas, tanto em homens (68,4%) como mulheres (56,8%). Entre os indivíduos com bruxismo, 82,6% relataram que gostariam de parar de fumar e aqueles que anteriormente tentaram (76,4%) sentiram-se mais estressados ao parar. O consumo de álcool também foi mais frequente no grupo com bruxismo (66,5% no gênero feminino e 73,5% no masculino). 88,4% relataram consumir álcool “para lidar com o estresse de forma adequada”. Resultados sugerem associação positiva entre bruxismo, consumo de álcool e tabagismo

The etiology of bruxism is not well defined. Different factors affecting the central nervous system are considered as risk factors for bruxism. Dental students are not immune to the bruxism, alcohol consumption and tobacco use, despite their training, knowledge of its effects and social responsibility. The purpose of this study was to evaluate the association between bruxism, alcohol consumption and tobacco use among Brazilian dental students. Participants were chosen among 180, 17-29 year-old students at the UNESP’s Dentistry School – Araçatuba Campus. They were divided into those with and without bruxism on the basis at validated clinical criteria. The clinical examinations were carried out by four standardized examiners (Intraexaminer and Interexaminer Unweighted kappa= 0.82, Weighted kappa= 0.89, respectively), in the clinic, with daylight and a tongue depressor. Bruxism was registered with the following categories: no wear facets, wear facets in enamel, dentine wear facets, facets wear half of the crown and wear facets more than 2/3 of the tooth crown. A self report validated questionnaire for alcohol consumption and tobacco use with 29 questions was completed by both groups. Fischer exact test and T-test were used and Odds Ratio and Confidence Interval was estimated. Bruxism was more frequent among cigarette smokers both in men (68.4%) and in women (56.8%). Among all respondents in this group, 82.6% reported that they would like to quit smoking and those who have tried previously to quit (76.4%) found it made them more stressed. Drinker was more frequent in the group with bruxism also (66.5% of the female and 73.5% of the male). 88.4% reported drinking alcohol because it “allows dealing with stress in an adequate way”. Results suggest a positive association between bruxism and alcohol consumption and tobacco use

Corrosion resistance of Ni-Cr alloys in different mouthwashes / Resistência à corrosão de ligas de Ni-Cr em diferentes enxaguatórios bucais

Várias ligas têm sido utilizadas na confecção de restaurações protéticas nos últimos anos. Essas ligas apresentam na sua composição ouro, paládio, prata, níquel, cobalto, cromo e titânio; quando na cavidade bucal são passíveis de corrosão, a qual pode empobrecer a estética e comprometer as propriedades físicas e biológicas. O objetivo deste trabalho foi avaliar a resistência a corrosão de duas ligas odontológicas, Ni-Cr e Ni-Cr-Ti em três tipos de colutórios bucais com diferentes ingredientes ativos: colutório I – 0.5g/l de cloreto de cetilpiridíneo +0.05 de fluoreto de sódio; colutório II -0.05 de fluoreto de sódio + 0.03% de triclosan e colutório III – 0.12% de diclonato de clorexidina. Curvas potenciodinâmicas foram realizadas por meio de potenciostato PAR283 e célula de vidro convencional de parede dupla para termostatização. Utilizou-se eletrodo de referência Ag/ AgCl, KClsat e auxiliar espiral de platina. A microestrutura das duas ligas foi observada por meio de microscopia ótica. Análise das curvas obtidas mostraram que a liga Ni-Cr foi menos reativa na presença de digluconato de clorexida a 0.12%, enquanto a liga Ni-Cr-Ti foi mais sensível para os outros dois tipos de colutório. Isto ocorreu, provavelmente, devido a presença de titânio na composição desta liga. Análise microestrutural revelou microsestrutura dendrítica na liga Ni-Cr e eutéticos na liga Ni-Cr-Ti

Several alloys have been used for prosthodontics restorations in the last years. These alloys have a number of metals that include gold, palladium, silver, nickel, cobalt, chromium and titanium and they are used in oral cavity undergo several corrosion. Corrosion can lead to poor esthetics, compromise of physical properties, or increased biological irritation. The objective of this study was evaluated corrosion resistance of two alloys Ni-Cr and Ni-Cr-Ti in three types of mouthwashes with different active ingredients: 0.5g/l cetylpyridinium chloride + 0.05% sodium fluoride, 0.05% sodium fluoride + 0.03% triclosan (with fluor) and 0.12% chlorohexidine digluconate. The potentiodynamic curves were performed by means of an EG&G PAR 283 potentiostat/galvanostat. The counter electrode was a platinum wire and reference electrode was an Ag/AgCl, KCl saturated. Before each experiment, working electrodes were mechanically polished with 600 and 1200 grade papers, rinsed with distilled water and dried in air. All experiments were carried out at 37.0oC in conventional three-compartment double wall glass cell containing mouthwashes. The microstructures of two alloys were observed in optical microscopy. Analysis of curves showed that Ni-Cr alloy was less reactive in the presence of 0.12% chlorohexidine digluconate while Ni-Cr-Ti alloy was more sensitive for others two types of mouthwashes (0.5g/l cetylpyridinium chloride + 0.05% sodium fluoride® and 0.05% sodium fluoride + 0.03% triclosan). This occurred probably due presence of titanium in this alloy. Microstructural analysis reveals the presence of dendritic and eutectic microstructures for NiCr and Ni-Cr-Ti, respectively

Parafunctionalactivities in brazilian children and adolescent / Prevalência de hábitos parafuncionais em crianças e adolescentes brasileiros

O crescimento craniofacial é o resultado da interação de mecanismos genéticos, hormonais e neurológicos, influenciados pela ação do meio ambiente e da função. As variações das funções normais de respiração, mastigação, deglutição, sucção e fonação, podem, devido à sua interdependência morfofuncional com o crescimento da face, resultar em má oclusões, as quais exercem papel determinante na conformação óssea e neuromuscular do sistema estomatognático. A prevenção e interceptação dos hábitos parafuncionais é de fundamental importância para o desenvolvimento físico e emocional da criança. O propósito deste trabalho foi determinar a prevalência de hábitos parafuncionais em alunos do ensino fundamental do Colégio Ipê de Assis (Assis, SP). No presente estudo foi aplicado questionário proposto pelo Núcleo de Diagnóstico e Tratamento das DTMs da Faculdade de Odontologia de Araçatuba, Unesp. O universo e a amostra foram compostos pelos 80 alunos do ensino fundamental do Colégio Ipê de Assis (Assis, SP). A execução do projeto foi autorizada pelo Comitê de Ética em Pesquisa da Faculdade de Odontologia de Araçatuba/Unesp.Todos os responsáveis pelos alunos receberam instrução arespeito da pesquisa quanto à preservação de identidade e prestação de esclarecimentos em caso de dúvida. Ademais, foi solicitado que assinassem otermo de consentimento esclarecido, a fim de viabilizar a participação dos alunos. Os alunos (10 a 14 anos0 foram classificados em dois grupos: Grupo I – gênero feminino e Grupo II - gênero masculino. Além disso, os Grupos I e II foram classificados segundo as séries em curso e os hábitos bucais apresentados. Entre os hábitos parafuncionais detectados, mascar chiclete foi o hábito mais prevalente para ambos os grupos (72,2% no Grupo I e 78,5% no Grupo II) e em todos os anos, seguido de apoiar a mão no queixo (69,5% para o Grupo I e 67% para o Grupo II). Morder a língua foi o hábito menos prevalente no Grupo II e dormir de bruços no Grupo I. A alta...

The etiology of TMD in children and adolescents is considered multifactorial and has been related to parafunctional habits.The objective of this research was to determine the prevalence of parafunctional habits in elementary school students of “Colégio Ipê de Assis” (Assis, SP - Brazil). In the present research was administered questionnaire (15 questions) proposed by the Center for Diagnosis and Treatment of TMD, School of Dentistry of Araçatuba, UNESP. The sample was composed of 80 elementary school students of the “Colégio Ipê de Assis” (Assis, SP - Brazil). The project was approved by the Ethics Committee in Research of the School of Dentistry of Araçatuba/ UNESP. All parents and responsible of the students received instruction about the research and preservation of identity and provide clarification if in doubt. Beyond that, they were requested to sign the informed consent in order to facilitate the participation of students. Females comprised 47,5% and males 52,5%, with age ranging from 10 to 14. The students were classified into two groups as follows: Group I-female, Group II- male. In addition, brazilian students from Groups I and II were classified according to type of oral habits presented. All students presented a parafunctional habit. Among the parafunctional habits chewing gum was the most common in both groups (72.2%, Group I and 78.5%, Group II) followed by resting chin on hand for both genders (69,5% for Group I and 67% for Group II). Tongue biting (5%) was less founded in Group II and stomach sleeping in Group I. The results obtained show the necessity of carring out preventive programs. Beside, resources of Health should increase preventive treatments

Sinais e sintomas na Síndrome de Costen associada a desordens temporomandibulares: relato de caso clínico / Signs and symptoms in Costen’s Syndrome in association with TMD: report of clinic case

Definida como um conjunto de sinais e sintomas auditivos em pacientes portadores de DTM, a Síndrome de Costen é caracterizada por sensação de plenitude auricular, hipoacusia, zumbido, otalgia e vertigem com nistagmo. Herpes, glossodinia, neuralgia glossofaringeal e trismo também podem estar associados. A Síndrome de Costen parece ter predileção pelo sexo feminino e na quarta década de vida. O acompanhamento multiprofissional desses pacientes é imperativo no seu reconhecimento e no estabelecimento de terapêutica eficaz. Relatou-se caso clínico de paciente com Síndrome de Costen cujo tratamento consistiu na orientação sobre a etiologia da desordem e sessões semanais de acupuntura. As características clínicas que levaram ao diagnóstico e plano de tratamento, bem como a eficácia da acupuntura como terapêutica de suporte também foram discutidas

Costen’s syndrome is defined as a set of auditory signs and symptoms in patients with TMD. It is characterized by ear fullness, hearing loss, tinnitus, ear pain and vertigo with nystagmus.It has predilection for females and fourth decade of life. The multidisciplinary monitoring of these patients is imperative in its recognition and the establishment of effective therapy. In this paper we report a case of Costen’s Syndrome patient whose treatment consisted of advice on the etiology of the disorder and weekly sessions of acupuncture. The clinical features that led to the diagnosis and treatment plan, and the effectiveness of acupuncture as supportive therapy were also discussed

Efeito do envelhecimento e do estresse crônico sobre a reação do tecido conjuntivo subcutâneo: estudo histológico em ratos / Effect of aging and chronic stress on the reaction of subcutaneous connective tissue: histological study in rats

As funções fisiológicas sofrem um retardo gradual que se inicia por volta de 25-30 anos e se estende até a morte. Além disso, esta alteração afeta mais gravemente as atividades mais complexas e as respostas mais intrincadas às tensões ou estresse. O propósito deste trabalho foi estudar histologicamente em ratos idosos o efeito do estresse crônico sobre a reação do tecido conjuntivo subcutâneo. Para tanto, 60 ratos, divididos em quatro grupos (GI (controle), GII (estressado), GIII (idoso) e GIV (Idoso/Estressado) receberam implante subcutâneo, bilateral e dorsal, de tubos de polietileno contendo soro fisiológico. Em grupos de cinco, os animais foram sacrificados aos 7,14 e 28 dias pós-operatórios. Os resultados obtidos permitiram observar reação inflamatória mais intensa e organização do tecido conjuntivo mais tardia nos animais idosos submetidos ao estresse

Physiological functions undergo a gradual retardation that begins around 25-30 years and extends to the death. Moreover, this change affects most severely the activities more complex and more intricate responses to tensions or stress. The purpose of this study was to evaluate histologically in aged rats the effect of chronic stress on the reaction of subcutaneous connective tissue. The purpose of this study was to evaluate histologically in aged rats the effect of chronic stress on the reaction of subcutaneous connective tissue. For this purpose, 60 rats were divided into four groups (GI (control), GII (stressed), GIII (elderly) and GIV (aged / stressed) received dorsal subcutaneous implants of polyethylene tubes containing saline solution. In groups of four animals were sacrificed at 7,14 and 28 days postoperatively. The results allowed to observe more intense inflammatory reaction and tissue organization later in the aged animals subjected to stress

Reação do tecido conjuntivo subcutâneo de ratos ao implante de Artglass®: estudo histológico / Reaction of the subcutaneous tissue of rats to Artglass™: histological study

Sistemas indiretos de resina composta têm sido rotineiramente indicados para confecção de restaurações em pacientes estressados. O propósito deste trabalho foi estudar histologicamente em ratos o efeito do estresse crônico sobre a reação do tecido conjuntivo subcutâneo ao implante de Artglass®. Para tanto, 60 ratos, divididos em quatro grupos (GI (controle), GII (estressado), GIII (Artglass®) e GIV (Artglass®/Estressado) receberam implante subcutâneo, bilateral e dorsal, de tubos de polietileno contendo soro fisiológico (Grupos I e II) ou Artglass® (Grupos III e IV). Em grupos de cinco, os animais foram sacrificados aos 7,14 e 28 dias pós-operatórios. Os resultados obtidos permitiram observar reação inflamatória mais intensa e organização do tecido conjuntivo mais tardia nos animais submetidos ao estresse

Indirect composite resin systems have been routinely recommended for making restorations in distressed patients. The purpose of this study was to evaluate histologically in rats the effect of chronic stress on the reaction of subcutaneous connective tissue after implant of Artglass™. For this purpose, 60 rats were divided into four groups (GI (control), GII (stressed), GIII (Artglass™) and GIV (Artglass™/ stressed) received dorsal subcutaneous implants of polyethylene tubes containing saline solution (GI and GII) or Artglass™ (GIII and GIV). In groups of four animals were sacrificed at 7,14 and 28 days postoperatively. The results allowed to observe more intense inflammatory reaction and tissue organization later in the animals subjected to stress

Compatibilidade entre alginato e gesso ortodônticos: capacidade de umedecimento sob influência da desinfecção do molde / Compatibility of alginate and orthodontic stone under disinfection

O mercado odontológico tem ofertado materiais de moldagem e modelo para uso ortodôntico garantindo modelos precisos. A compatibilidade entre estes materiais é definida pelo umedecimento das superfícies do molde pela mistura água/gesso sobre ela vazada e sofre influência de método de desinfecção do molde e solução desinfetante utilizada. Avaliou-se a influência da desinfecção por aspersão com hipoclorito de sódio 1% sobre a capacidade de umedecimento de duas marcas comerciais de alginato (Jeltrate® e Orthoprint®) por duas marcas comerciais de gesso pedra tipo III (Gesso Rio® e Orthogesso®). Foram confeccionados 20 moldes de cada tipo de alginato, os quais foram divididos em dois grupos (Água e Hipoclorito de sódio), recebendo respectivamente aspersão com água e hipoclorito de sódio 1%. Cada grupo de moldes foi então novamente dividido em dois subgrupos, sendo que sobre a superfície dos moldes foram vertidos 2 ml de gesso (Gesso Rio® ou Orthogesso®). Atingida a presa final, os modelos foram seccionados vertical e medianamente e montados para leitura do ângulo de contato em microscópio Carl Zeiss (0.001). Os resultados obtidos foram submetidos ao teste ANOVA e mostraram significância estatística para as soluções utilizadas. Conclui-se que a desinfecção dos moldes com aspersão de hipoclorito de sódio 1% melhorou a capacidade de umedecimento dos alginatos pelos gessos estudados

The dental trade has offered dental impression and dental stone for orthodontic use ensuring accurate models. The compatibility between these materials is defined by the wetting of the model surfaces by the mixture water/stone poured over it and the influenced by the method of disinfection of model and disinfectant solution used. It was evaluated the influence of spray disinfection with sodium hypochlorite 1% on the wettability of two commercial alginate (Jeltrate® - Dentsply and Orthoprint® - Zhermack) at two commercial type III gypsum (Rio® - ME and AOBussoli Orthogesso Orthogesso®-SA). Twenty models were fabricated for each type of alginate, which were divided into two groups (water and sodium hypochlorite), receiving respectively water and sodium hypochlorite 1% spray. Each group of models was then further divided into two subgroups, and on their surface were poured 2 ml of type III gypsum (Gesso Rio® or Orthogesso®). Reached the final setting of the gypsum specimens were sectioned vertically and medially, settled water with sandpaper No. 400 and mounted on suitable device for reading (in the right and left) of the contact angle Carl Zeiss microscope (precision, 001). The results were submitted to ANOVA and founded statistical significance for solutions used. It was concluded that sodium hypochlorite spray improved wettability of alginates studied

Efeito do estresse crônico e benzodiazepínicos no reparo ósseo: estudo histológico em ratos / Effect of chronic stress and benzodiazepines on bone repair: histologic study in rats

Aceita-se o estresse como um fator ambiental capaz de predispor o indivíduo à depressão. Os benzodiazepínicos têm sido prescritos como drogas eficazes nessas situações. O propósito deste trabalho foi estudar histologicamente o efeito do estresse crônico e drogas benzodiazepínicas sobre o reparo ósseo. Cavidades ósseas foram criadas em ambas as tíbias de 40 ratos machos, divididos em 2 grupos: Controle e Tratado. Neste, o estímulo estressor foi aplicado nos 40 dias pré-operatórios e em todos os dias pós-operatórios até o sacrifício, pela manhã por 2 horas, por meio da imobilização por contenção. Esses animais também receberam benzodiazepínico do grupo Diazepam, diariamente, na concentração de 5mg/Kg/peso corporal nos 15 dias pré-operatórios. Em grupos de cinco, os animais foram sacrificados aos 7, 14, 30 e 60 dias pós-operatórios. Aos 7 dias pós-operatórios, enquanto o grupo controle exibia tecido conjuntivo rico em fibroblastos, o grupo tratado mostrava tecido conjuntivo neoformado, com escassos fibroblastos e vasos capilares ao lado de linfócitos e macrófagos. Aos 14 dias pós-operatórios, o Grupo Controle exibiu trabeculado ósseo neoformado enquanto o Grupo Tratado evoluiu para trabéculas ósseas delgadas, com numerosos osteoblastos em suas bordas. Aos 30 dias pós-operatórios a reparação óssea está completa em ambos os grupos. Aos 60 dias pós-operatórios as características observadas nos grupos controle e tratado são semelhantes ao período anterior, porém com osteogênese mais avançada

Stress is an environmental factor that may predispose individuals to depression. Benzodiazepines have been prescribed as effective drugs in these situations. The purpose of this study was histological evaluate of the effect of chronic stress and benzodiazepine drugs on bone healing. Bone cavities were created in both tibias of 40 male rats were divided into two groups: Control and Treaty. In this, the stressor stimulus was applied 40 days pre-operative and all post-operative days until sacrifice in the morning for 2 hours, by immobilizing restraint. These animals also received diazepam benzodiazepine group, daily, at a concentration of 5mg/Kg/peso body within 15 days of preoperative. In groups of five animals were sacrificed at 7, 14, 30 and 60 days post-surgery. At 7 days postoperatively, while the control group exhibited tissue rich in fibroblasts, the treated group showed newly formed tissue with few fibroblasts and capillaries along with lymphocytes and macrophages. At 14 days postsurgery, the control group showed newly formed trabecular bone while the treated group progressed to thin trabecular bone with numerous osteoblasts on their borders. At 30 days post-operative bone healing is complete in both groups. At 60 days post-operative characteristics observed in the treated and control groups are similar to the previous period, but with more advanced osteogenesis

Effects of thermocycling on mechanical properties of soft lining materials / Influencia del termociclado sobre las propiedades físicas de los materiales softs para rebasado

Soft linings are materials used to reduce the tension and forces of mastication, forming all or part of the fitting surface of a denture. This study evaluated the effect of thermocycling on waterabsorption, solubility, Shore A hardness and color stability of permanent soft liner materials. MATERIAL AND METHODS: Two chemically activated soft liner materials (Sofreliner S; GC Reline Ultrasoft) were tested. Twenty cylindrical specimens (30.0 x 1.0 mm) were prepared for measuring water absorption and solubility and another twenty (30.0 x 3 mm) for analyzing Shore A hardness and color stability. Color was measured by a spectrophotometer before and after 2000 thermocycles. A one-way ANOVA test and Tukey test at a 5% confidence level (p<0.05) were performed. RESULTS: The results did not show statistical differences for water absorption, solubility or color stability. The post-thermocycling Shore A hardness values were significantlyhigher than those before the treatment. CONCLUSION: Thermocycling of soft liner materials increased Shore A hardness.(AU)

Objetivo: Los materiales para rebasado tienen como propósito disminuir la tensión, la presión masticatoria en los tejidos de soporte y aumentar la retención de la dentadura, además de serindicados para prótesis buco-maxilo-faciales. El objetivo de este estudio fue evaluar el efecto del termociclado en los materiales para rebasado blandos considerados definitivos y evaluar lasalteraciones en relación a la absorción de agua, solubilidad, dureza Shore A y estabilidad de color. Materiales y Métodos: Dos materiales para rebasado blandos definitivos (Sofreliner S y GC Reline Ultrasoft) fueron examinados. Fueron confeccionados 20 muestras, midiendo 30 mm de diámetro x 1 mm deespesor, aquellos destinados al test de absorción y solubilidad y 20 muestras con 30 mm de diámetro x 3 mm de espesor para dureza y estabilidad de color. Fueron realizados los tests deabsorción y solubilidad. La dureza fue medida en un durometroy la estabilidad de color por medio de un spectrofotómetro en los periodos inicial y después de 2000 ciclos de termociclaje. Una vez obtenidos los datos, estos fueron submetidos al análisis de varianza (ANOVA) seguido por el test Tukey (p<0,05). Resultados:En relación a la absorción, solubilidad y estabilidad de color no hubo diferencia estadísticamente significativa entre losmateriales, en relación al test de dureza fue constatada una diferencia estadísticamente significativa entre los periodos y los materiales examinados. Conclusión: El termociclaje no interfirióen la absorción, solubilidad y estabilidad de color de los materiales evaluados, sin embargo interfirió de forma significativaen la dureza Shore A. Los materiales tuvieron sus valores promedios de dureza aumentados después del termociclaje.(AU)