Influence of thermal cycles and disinfection on the roughness, microhardness and color of PETG/TPU and PMMA.

BACKGROUND: Occlusal splints can protect teeth during bruxism, preventing tooth wear, as well as during sports activities, shielding them from impacts. OBJECTIVES: To verify the influence of thermal cycles and disinfection on the roughness, microhardness and color of polyethylene terephthalate glycol/thermoplastic polyurethane (PETG/TPU) and poly(methyl methacrylate) (PMMA). MATERIAL AND METHODS: Thirty-six PETG/TPU samples and 36 PMMA samples were prepared (ø10 mm × 3 mm). Six groups were created according to the material and the disinfection method used (n = 12 each): PETG/TPU (glister), PETG/TPU (hypochlorite), PETG/TPU (soap), PMMA (glister), PMMA (hypochlorite), and PMMA (soap). Roughness, Knoop microhardness and color evaluations were performed before the experiments (T1), after thermocycling (T2) and after disinfection (T3). Three-way repeated measures analysis of variance (ANOVA) and Tukey's test were used for statistical evaluations. RESULTS: For roughness and color, ANOVA showed statistical significance based on the interaction between thermal cycling, material and disinfectant factors. In terms of Knoop microhardness, ANOVA showed statistical significance based on the interaction between thermal cycling and material factors. CONCLUSIONS: Roughness results were clinically acceptable in all groups at all time points, except the PETG/TPU and PMMA groups disinfected with hypochlorite. Microhardness significantly increased for both materials after thermal cycling, and at all time points, the microhardness of PMMA was significantly higher than that of PETG/TPU. After thermal cycling, the color changes were clinically unacceptable in all groups.

Cytotoxicity of cleaning agents for ocular prostheses.

BACKGROUND: Polymethylmethacrylate (PMMA) is the most used material for the manufacturing of eye prostheses. OBJECTIVES: To investigate the cytotoxicity of different cleaning agents for ocular prostheses on human conjunctival cells. MATERIAL AND METHODS: Six groups of specimens were created (saline, soap, 4% chlorhexidine, hydrogen peroxide, 1% triclosan, and citronella oil). Three specimens were made for each disinfectant at each disinfection period (1, 7, 15, 30, 60, and 90 days), totaling 108 specimens. Thus, the specimens were disinfected, with different disinfectants, for different periods of time. After each disinfection process, the specimens were washed with sterile distilled water. A human conjunctival cell line was grown on the acrylic resin specimens and then cytotoxicity tests (MTT and Neutral Red (NR)) were performed. A negative control (untreated cell cultures) and positive control (Tween 20) were created. Two-way analysis of variance (ANOVA) and Bonferroni test were performed (p < 0.05). RESULTS: For the MTT and NR tests, when there was a significant difference between the disinfectant and negative control, the disinfectant generated a significant reduction in cell proliferation most of the time. CONCLUSIONS: All reductions in cell proliferation caused by the disinfectants were clinically acceptable. All disinfectants tested in this study were found to be non-cytotoxic to human conjunctival cells.

Effect of glaze and chlorhexidine on physical and mechanical properties of bis-acryl resin: An in situ study.

BACKGROUND: Temporary prosthesis protects the oral tissues, in addition to providing aesthetic look and masticatory function until a definitive prosthesis is manufactured. OBJECTIVES: To evaluate the effect of glaze and 0.12% chlorhexidine (CHX) on the physical and mechanical properties of bis-acryl, and to evaluate the antimicrobial efficacy of CHX. MATERIAL AND METHODS: Eighty specimens of bis-acryl resin were made. Over 40 of them the glaze was applied. One specimen with and 1 specimen without glaze were placed in niches of an appliance manufactured for each patient. Each of the 20 volunteers received 2 devices. Initially, the volunteers used one device and treated it with sucrose for 7 days (control), and later they used the other device and treated it with sucrose and CHX for 7 days (test). Color, microhardness, roughness, surface energy, and insoluble extracellular polysaccharides (EPS) tests were performed. All results were submitted to the Tukey's test, with the exception of the EPS results, which were submitted to the Student's t test. RESULTS: The ΔE00 of the unglazed control group was significantly higher than that of the unglazed test group. In all groups, a significant decrease in microhardness occurred over time. At both times, the glaze significantly increased the microhardness of the specimens (in all the glazed groups). At the final time, the test glaze group showed significantly higher microhardness compared with the control glaze group. Roughness in the groups without glaze increased significantly with CHX treatment over time. At both times, the glaze generated a significant reduction in roughness in the control and test groups. There was a significant reduction in surface energy over time in all groups. In most comparisons, the glazed groups showed significantly higher surface energy values compared with the unglazed control group. At the final time point, the unglazed test group showed a significantly higher surface energy value than the unglazed control group; and the glazed test group showed a significantly higher surface energy value compared with the glazed control group. The resins that received CHX had a significantly lower amount of biofilm. CONCLUSIONS: Color values were clinically acceptable in all tested groups. At both time points, the roughness values were clinically acceptable only in the glazed groups. Glaze increased the microhardness of the specimens. Microhardness and surface energy were reduced over time in all groups. Chlorhexidine can help prevent microhardness degradation. Glaze and CHX can increase surface energy. Chlorhexidine reduced the amount of bacterial biofilm.

Use of stress analysis methods to evaluate the biomechanics of oral rehabilitation with implants.

Because the biomechanical behavior of dental implants is different from that of natural tooth, clinical problems may occur. The mechanism of stress distribution and load transfer to the implant/bone interface is a critical issue affecting the success rate of implants. Therefore, the aim of this study was to conduct a brief literature review of the available stress analysis methods to study implant-supported prosthesis loading and to discuss their contributions in the biomechanical evaluation of oral rehabilitation with implants. Several studies have used experimental, analytical, and computational models by means of finite element models (FEM), photoelasticity, strain gauges and associations of these methods to evaluate the biomechanical behavior of dental implants. The FEM has been used to evaluate new components, configurations, materials, and shapes of implants. The greatest advantage of the photoelastic method is the ability to visualize the stresses in complex structures, such as oral structures, and to observe the stress patterns in the whole model, allowing the researcher to localize and quantify the stress magnitude. Strain gauges can be used to assess in vivo and in vitro stress in prostheses, implants, and teeth. Some authors use the strain gauge technique with photoelasticity or FEM techniques. These methodologies can be widely applied in dentistry, mainly in the research field. Therefore, they can guide further research and clinical studies by predicting some disadvantages and streamlining clinical time.

Influence of torque and bone type on stability quotient of two implant platforms: a clinical trial.

The objective of this study was to analyze the influence of insertion torque, bone type, and peri-implant bone loss on implant stability quotient (ISQ) of cylindrical external hexagon (EH) and Morse Taper (MT) implants. Forty-four single implants were placed in the edentulous areas of 20 patients who met the inclusion and exclusion criteria. Immediately after implant placement (t1) and after osseointegration (four and six months for mandible and maxilla, respectively) (t2), insertion torque, resonance frequency, and peri-implant bone loss were measured using probing depths and digital periapical radiography. A significant difference was noted in the ISQ values between t1 and t2 in type III bone for EH and MT implants. No significant difference in bone loss values was observed when comparing bone types for EH or MT in all evaluated sites. Based on marginal bone loss assessed using radiography, there was no significant difference between the MT and EH groups. A positive correlation between torque and ISQ t1 value was observed for MT (correlation: 0.439; p = 0.041) and EH (correlation: 0.461; p = 0.031) implants. For EH and MT implants, the greater the insertion torque, the greater was the ISQ value (moderately positive correlation). A weak negative correlation was found between bone type and ISQ t1 for MT implants. Contrarily, no correlation was observed between bone type and ISQ t1 for EH implants. In all cases, bone loss around the implants was clinically normal.

Influence of Different Restoring Materials on Stress Distribution in Prosthesis on Implants: A Review of Finite Element Studies.

The selection of material used on the occlusal surface of implant-supported prostheses is important, as these materials can transmit destructive forces to the interface between the alveolar bone and the implant. Different prosthetic materials are suggested for implant-supported prostheses. The choice of prosthetic material is a controversial issue, and there is a consensus that implant survival is not affected by the prosthetic material. Three-dimensional finite element studies are often used in dentistry to estimate the stress distribution that occurs in the implant system, peri-implant bone, and prosthetic components. To analyze the influence of the prosthetic restorative material on the stresses in bone tissue and peri-implant through a literature review of three-dimensional finite element studies. The search for articles was performed in the PubMed/Medline database up to November 2021. The selected articles were independently evaluated by two different reviewers. The information collected was author and year of publication, dimensions of implants used, the material used in the prosthetic crown, simulated force and direction, and conclusion and effect. After searching, 14 studies were selected for full reading, and based on the inclusion and exclusion criteria, all could be included in this review. The articles were based on evidence-based laboratory medicine. After analyzing these articles, it was concluded that the prosthetic materials used on the occlusal surface do not interfere with the destruction of stresses to the bone and peri-implant tissue, both in single prostheses and protocol-type prostheses, when three-dimensional finite element method is used.

Halitosis and Pain Threshold of Peri-Implant Tissues: An Observational Cohort Study.

In this study, we aimed to evaluate the halitosis and pain threshold of the peri-implant soft tissues in individuals rehabilitated with implant-supported prostheses. Forty-eight subjects were divided into four groups (n = 12) according to their prosthetic rehabilitation: single-tooth fixed prosthesis, multi-tooth fixed prosthesis, overdentures, and the Brånemark protocol. Halitosis was measured using a halimeter, whereas the pain threshold was measured using Von Frey monofilaments. Measurements were taken before (t0) and 30 days after (t1) placement of healing caps, and at the time of (t2) and 30 days after (t3) prosthetic placement. Halitosis data were analyzed using the chi-square test and Bonferroni correction (p < 0.05). Two-way ANOVA and Tukey's test (p < 0.05) were used to analyze pain threshold data. We noted an association between halitosis and time for the Brånemark protocol [X2(6) = 18.471; p = 0.005] and overdenture groups [X2(6) = 17.732; p = 0.007], and between halitosis and type of prosthesis only at t0 [X2(6) = 12.894; p = 0.045]. The interaction between time and the type of prosthesis significantly interfered with the mean pain threshold values (p = 0.001). At most time points, the majority of participants in each group had clinically unacceptable halitosis. After 30 days of using the prostheses, the overdenture group had a lower pain threshold compared to the Brånemark protocol group.

An effective technique to posterior resin composite restorations.

AIM: The aim of this study is to present a clinical case in which an occlusal matrix device was used in a patient who needed to restore a posterior tooth. MATERIAL AND METHODS: A direct duplicate occlusal appliance was used (biteperf) in a patient who needed an occlusal restoration in two posterior teeth. RESULTS: Using the matrix helps having fast and accurate reproduction of the original anatomical details of the occlusal surface. The final result surprised with the presented restoration in terms of esthetic quality, despite the simplicity of the technique. CONCLUSION: Posterior teeth with initial lesions were confined to the occlusal surface of anatomically complex or fissured anatomy with or without signs of proximal caries wich are ideal candidates for this technique. The overlying enamel surface must be relatively intact; lesions of hidden or occult caries. CLINICAL SIGNIFICANCE: The aesthetic and time-saving benefits of the occlusal device (biteperf) are immediately clear. The matrix allows the fast and accurate reproduction of the anatomic details of the original occlusal surface of the tooth. The professionals who lack an artistic penchant and marked manual ability will be able to carry out excellent posterior resin composite restorations.

Extended-pour and conventional alginates: effect of storage time on dimensional accuracy and maintenance of details.

OBJECTIVE: This study aimed to evaluate the dimensional stability and maintenance of details of conventional and high stability alginates up to 5-day storage. METHODS: Two types of alginates were selected (n=10) for this study, conventional (Hydrogum) and high stability alginates (Hydrogum 5), which were produced with the aid of a cylindrical metal block and a ring-shaped metal mold (Specifications 18, 19, and 25, ANSI/ADA). Ten images were obtained from the molds for the dimensional stability test, which were taken immediately after their production and at each different storage periods (15 min, 24 h, 48 h, 72 h, 96 h, and 120 h) by a digital camera. The specimens were kept hermetically sealed in plastic bags (23°C) and then used to obtain 140 (n=70) dental stone models, used in the detail reproduction test, in which the angular accuracy of three grooves (20 µm, 50 µm, and 75 µm) was observed at each period. The details reproduction accuracy was classified using a predetermined score classification. Measurements of dimensional changes were made in the Corel DRAW X6 program. The data were submitted to the Student's t-test (α?#8197;= 0.05). RESULTS: A statistically significant difference concerning the size of the matrix was observed after 24h for both alginates, and a statistically significant negative linear dimensional change (contraction) was verified after 24 h of storage (1.52% for the high stability alginate, and 1.32% for the conventional alginate). The high stability alginate kept the full details for 72 hours, while the conventional alginate, for 24 h. Both alginates reproduced the 75 µm groove at all storage periods. CONCLUSION: Impressions made with both alginates presented satisfactory clinical results when the alginates were immediately poured.

Evaluation of hardness and color stability in the soft lining materials after thermocycling and chemical polishing.

The aim of this study was to evaluate the Shore A hardness and color stability of two soft lining materials after thermocycling and when chemical polishing was used or omitted. Two acrylic-based soft lining materials were tested: Coe-Soft and Soft Confort, 14 specimens were made for each material. They were distributed in four groups according to the treatment performed. The specimens were thermocycled (1000 cycles) and half of the group submitted to chemical polishing (methyl methacrylate). Shore A hardness was determined and color stability was calculated by means of Commission International de l'Eclairage Lab uniform color scale using a spectrophotometer, the measurements were made immediately after deflasked, chemical polishing and thermocycling. Analysis of variance (ANOVA) and Tukey's tests were performed at p < 0.01. Color changes (deltaE) were observed after thermocycling in both soft lining materials: Soft Confort (10.60) showed significantly higher values than Coe-Soft (4.57). Coe-Soft (26.42) showed higher Shore A hardness values than Soft Confort (19.42). Chemical polishing did not influence in the color stability of both materials; however, influenced in the hardness values of Coe-Soft.

Tratamento reabilitador com prótese obturadora em paciente acometido por maxilectomia parcial: relato de caso / Rehabilitative treatment with obturator prosthesis in a patient suffering from partial maxillectomy: case report

Introdução: O tratamento de tumores malignos ou benignos, podem resultar em procedimentos cirúrgicos, como a maxilectomia parcial ou total, gerando comunicação bucosinusal nos pacientes. Uma forma de resolver estas alterações maxilofaciais é através do tratamento reabilitador com próteses obturadoras a fim de restabelecer a função mastigatória, estética, fonética e psicológica. Objetivo: o objetivo deste trabalho foi relatar o caso clínico de um paciente oncológico que foi reabilitado com prótese obturadora devido à maxilectomia por neoplasia maligna de seio maxilar. Relato de caso: Paciente de 62 anos, sexo masculino, procurou atendimento odontológico no Centro de Oncologia Bucal da Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP) de Araçatuba ­ SP após a realização de uma maxilectomia parcial com comunicação bucosinusal e foi encaminhado para o Curso de Especialização em Prótese Dentária da Faculdade de Odontologia ­ Unesp/Araçatuba-SP para a reabilitação. Foi proposto, primeiramente a realização da prótese obturadora para fechar a comunicação bucosinusal e uma prótese total inferior para o arco antagonista e, posteriormente, a realização de uma prótese facial. Conclusão: O tratamento reabilitador com próteses obturadoras possui um bom resultado estético e funcional, favorecendo uma melhor função mastigatória e fonética, e melhorando consideravelmente a condição psicológica que é muito afetada nos pacientes submetidos a maxilectomia total ou parcial, sendo necessário uma boa interação com toda a equipe multiprofissional envolvida para que haja um melhor tratamento integrado para a reabilitação e melhora da qualidade de vida(AU)

Introduction: The treatment of malignant or benign tumors can result in surgical procedures, such as partial or total maxillectomy, generating oral communication in patients. One way to resolve these maxillofacial changes is through rehabilitative treatment with obturator prostheses in order to reestablish masticatory, aesthetic, phonetic and psychological function. Objective: the objective of this work was to report the clinical case of a cancer patient who was rehabilitated with an obturator prosthesis due to maxillectomy for malignant neoplasia of the maxillary sinus. Case report: A 62-year-old male patient sought dental care at the Oral Oncology Center of the Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP) in Araçatuba ­ SP after undergoing a partial maxillectomy with oral cavity and was referred for the Specialization Course in Dental Prosthesis at the Faculty of Dentistry ­ Unesp/Araçatuba-SP for rehabilitation. It was proposed, firstly, to create an obturator prosthesis to close the bucosinusal communication and a total lower prosthesis for the antagonistic arch and, later, to create a facial prosthesis. Conclusion: Rehabilitative treatment with obturator prostheses has a good aesthetic and functional result, favoring better chewing and phonetic function, and considerably improving the psychological condition that is greatly affected in patients undergoing total or partial maxillectomy, requiring good interaction with the entire the multidisciplinary team involved so that there is better integrated treatment for rehabilitation and improved quality of life

Visão atual da Revista Odontológica de Araçatuba: divulgação nacional e a caminho da internacionalização com seus artigos publicados / Current view of the Dental Journal of Araçatuba: national dissemination and on the way to internationalization with its published articles

A Revista Odontológica de Araçatuba é um periódico online, de acesso gratuito cujo as publicações são indexadas em importantes bases de dados, divulgando deste modo trabalhos científicos produzidos por instituições do estado de São Paulo e de outros centros de pesquisa de todo o país. O intuito deste trabalho é analisar de modo quantitativo as publicações realizadas no período de 2018 a 2023, as classificando de acordo com a sua natureza (Pesquisa cientifica, Revisão de literatura ou relato de caso) e de acordo com a sua origem (UNESP ­ FOA, misto ou outro centro de ensino) e comparar os resultados obtidos aos dados presentes nos estudos referentes ao período de 2001 a 2011 e ao estudo referente ao período de 2012 a 2017. Foi realizada uma pesquisa bibliográfica que compreendeu as publicações dos anos de 2018 a 2023, abrangendo 18 periódicos e um suplementar, totalizando 167 artigos. Neste intervalo de tempo, houve uma predominância de relatos de casos (55,08%) em comparação as revisões de literatura (22,15%) e as pesquisas cientificas (22,75%). Os artigos oriundos de outros centros de pesquisa foram a maioria (82,03%) e 8 dos artigos presentes foram em língua inglesa. Podemos concluir que a Rev. Odontol. Araçatuba se tornou um periódico de relevância nacional com predominância de compromisso clinico e que está em processo de internacionalização(AU)

The Dental Journal of Araçatuba is an online journal, with free access, whose publications are indexed in important databases, publishing scientific works produced by institutions in the state of São Paulo and other research centers across the country. The purpose of this work is to analyze, in a quantitative way, the publications carried out in the period from 2018 to 2023, classifying them according to their nature (Scientific research, Literature review or case report) and according to their origin (UNESP ­ FOA , mixed or other teaching center) and compare the results obtained with the datas presents in the studies referring to the period from 2001 to 2011 and the study referring to the period from 2012 to 2017. A bibliographical research was carried out that included publications from the years 2018 to 2023, covering 18 periodicals and one supplementary, totaling 167 articles published. In this time period, case report articles predominated (55,08%) compared to literature reviews (22.15%) and scientific research (22,75%). The majority of articles came from other research centers (82.03%) and 8 of the published articles were in English. We can conclude that Journal Dental of Araçatuba became a periodical of national relevance with a predominance of clinical commitment and which is in process of internationalization(AU)

Halitosis and Pain Threshold of Peri-Implant Tissues: An Observational Cohort Study

Abstract In this study, we aimed to evaluate the halitosis and pain threshold of the peri-implant soft tissues in individuals rehabilitated with implant-supported prostheses. Forty-eight subjects were divided into four groups (n = 12) according to their prosthetic rehabilitation: single-tooth fixed prosthesis, multi-tooth fixed prosthesis, overdentures, and the Brånemark protocol. Halitosis was measured using a halimeter, whereas the pain threshold was measured using Von Frey monofilaments. Measurements were taken before (t0) and 30 days after (t1) placement of healing caps, and at the time of (t2) and 30 days after (t3) prosthetic placement. Halitosis data were analyzed using the chi-square test and Bonferroni correction (p < 0.05). Two-way ANOVA and Tukey's test (p < 0.05) were used to analyze pain threshold data. We noted an association between halitosis and time for the Brånemark protocol [X2(6) = 18.471; p = 0.005] and overdenture groups [X2(6) = 17.732; p = 0.007], and between halitosis and type of prosthesis only at t0 [X2(6) = 12.894; p = 0.045]. The interaction between time and the type of prosthesis significantly interfered with the mean pain threshold values (p = 0.001). At most time points, the majority of participants in each group had clinically unacceptable halitosis. After 30 days of using the prostheses, the overdenture group had a lower pain threshold compared to the Brånemark protocol group.

Resumo Este estudo teve como objetivo avaliar a halitose e o limiar de dor dos tecidos moles peri-implantares em indivíduos reabilitados com próteses implantossuportadas. Um total de 48 indivíduos foram divididos em quatro grupos (n=12), de acordo com as reabilitações: prótese fixa unitária, prótese fixa multidentária, sobredentadura e protocolo de Brånemark. A halitose foi medida com um halímetro, enquanto o limiar de dor foi medido com monofilamentos de von Frey. As medições foram feitas antes (t0) e 30 dias após (t1) a colocação das tampas de cicatrização e no momento (t2) e 30 dias após (t3) a colocação da prótese. Os dados de halitose foram analisados por meio do teste qui-quadrado e correção de Bonferroni (p < 0,05). ANOVA de duas vias e o teste de Tukey (p < 0,05) foram usados para analisar os dados do limiar de dor. Observou-se associação entre halitose e tempo para o protocolo de Brånemark [X2(6) = 18,471; p = 0,005] e grupos overdenture [X2(6) = 17,732; p = 0,007], e entre halitose e tipo de prótese apenas em t0 [X2(6) = 12,894; p = 0,045]. A interação entre o tempo e o tipo de prótese interferiu significativamente nos valores médios do limiar de dor (p = 0,001). Na maioria dos pontos de tempos, a maioria dos participantes de cada grupo apresentava halitose clinicamente inaceitável. Após 30 dias de uso das próteses, o grupo overdenture apresentou menor limiar de dor em comparação ao grupo do protocolo de Brånemark.

Prótese overdenture: sistema o'ring / Overdenture prosthesis: o'ring system

Overdenture é uma prótese total que se caracteriza por usar apoios retentivos para que aumente sua estabilidade e retenção na cavidade bucal, gerando assim menor desconforto ao paciente e melhor adaptação. A Prótese overdenture dentossuportada necessita de elementos dentais remanescentes com canais tratados endodonticamente e que possuam suporte periodontal adequado. O objetivo deste relato de caso clínico é expor a sequência de confecção de uma prótese overdenture dentossuportada maxilar associada a uma prótese total convencional mandibular, com os passos clínicos detalhados por meio de uma abordagem teórica e visual. Esse tipo de reabilitação favorece a adaptação do paciente à nova condição, visto que o uso de próteses totais convencionais pode causar certo desconforto ao paciente devido à falta de retenção e estabilidade. Essa manutenção dos dentes remanescentes favorece à manutenção óssea e a futura decisão do paciente em optar pela instalação de implantes dentários, podendo confeccionar próteses implantorretidas (overdentures) ou implantossuportadas (protocolo).O Paciente demonstrou-se satisfeito com o resultado estético e funcional após a instalação da prótese concretizando que o tratamento é viável(AU)

Overdenture is a denture that utilizing retentive supports for increase stability and retention in oral cavity. The tooth-supported overdenture require dental elements with root canal therapy and good periodontal support. The aim of this study is to report the confection of a maxillary tooth-supported overdenture associated with mandibular denture and your clinical steps. This rehabilitation promotes the patient's adaptation the new condition, since the use of conventional dentures may cause discomfort due to lack of retention and stability. The preservation of dental elements promotes bone maintenance and forthcoming decision of the patient in the installation of dental implants that can choose implantretained or implant-supported prosthesis. Patient was satisfied with aesthetic and functional result after installation of prosthesis(AU)

Surface characterization of polymers used in fabrication of interim prostheses after treatment with photopolymerized glaze.

The material used for interim prostheses fabrication must present excellent physical properties for greater longevity in the face of environmental conditions, which can occur in the oral cavity. The purpose of this study was to evaluate the effect of a photopolymerized glaze on the physical and mechanical properties of polymers used for the fabrication of interim prostheses, before and after thermocycling and immersion in staining solutions. One hundred samples of composite and acrylic resins were fabricated: Dencor chemically activated acrylic resin (CAAR) (n=20) and heat-polymerized acrylic resin (HPAR) (n=20), Charisma (n=20), Structur (n=20), and Protemp (n=20). A mechanical polishing was performed on half of the samples, and a chemical polishing was performed on the remaining samples. Subsequently, all samples were submitted to thermocycling and immersion in coffee staining solution for 21days. Analysis of color and microhardness, as well as atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive x-ray spectrometry (EDS) were performed. The data were submitted to repeated-measures analysis of variance (ANOVA), followed by the Tukey test (α=0.05) and the Student t-test (α=0.05). It was verified that the glaze decreased the chromatic alteration values, and increased the microhardness values of the samples, with the exception of the Charisma resin. The samples that did not receive chemical polishing had the greatest number of surface irregularities. This study concluded that the groups with glaze presented less color alteration. In addition, Charisma and Structur resins exhibited the greatest chromatic stability. As to the microhardness, the values were greater when the samples were treated with the glaze, with the exception of the Charisma group.

Reabilitação de pacientes com comunicação buco nasal: relato de casos / Rehabilitation of patients with oral and nasal communication: case report

A sobrevivência de pacientes com câncer de cabeça e pescoço vêm melhorando, entretanto, algumas deformidades podem ocorrer devido dos tratamentos cirúrgicos que geram mutilações bucomaxilofaciais como perda de dentes, estruturas do palato, língua ou assoalho, resultando em alterações na fonética, mastigação e deglutição. Nesses casos há a necessidade que seja realizado uma reabilitação protética buscando torná-los indivíduos com menos problemas sociais, psicológicos e físicos, visto que mais procedimentos cirúrgicos estão contra indicados para solucionar os efeitos colaterais gerados pelo tratamento das neoplasias. Esse tipo de reabilitação protética com prótese ou placa obturadora possibilita benefícios na fonética, facilita a convivência social e atividades nutricionais como alimentação e deglutição, permitindo ao paciente uma vida com menos constrangimentos. Este trabalho tem como objetivo relatar dois casos clínicos onde os pacientes foram submetidos a reabilitação com placa obturadora palatina feitos após cirurgias oncológicas. Os pacientes de gêneros diferentes e com comunicações buco-nasal similares receberam o mesmo planejamento reabilitador que foram confeccionadas a partir de um molde que foi enviado ao laboratório. Após a instalação foi possível verificar que houve sucesso no tratamento, notando uma melhora imediata comprovando a eficácia do método reabilitador(AU)

This paper relates two clinical cases where patients were recovered with a palatal splint made after oncological surgeries. Survival of patients and necks can occur, however, some deformities can occur during oral and maxillofacial treatment, such as the appearance of teeth, palate structures, mutilations or posterior jaws, leading to changes in aesthetics, surgery and swallowing. If the need to perform a prosthetic rehabilitation is necessary so that the results are seen with less problems, psychological and physical, that more procedures are performed so that the effects of neoplasms are contraindicated by the treatment. This type of prosthetic rehabilitation with prosthesis or obturator plate provides benefits in phonetics, facilitates social coexistence and nutritional activities such as eating and swallowing, allowing the patient a life with less constraints. Patients of different genders and with similar oral and nasal communications received the same rehabilitation plan that were made from a mold that was sent to the laboratory. After installation, it was possible to verify that the treatment was successful, noting an immediate improvement, proving the effectiveness of the rehabilitation method(AU)

Novos materiais livres de metal para confecção de próteses monolíticas em sistema CAD/CAM / New metal-free materials for making monolithic prostheses in CAD/CAM system

A busca por naturalidade dos procedimentos restauradores em reabilitação oral tem contribuído para o desenvolvimento de vários tipos de materiais livres de metal ("metal free"). A confecção de próteses com estes sistemas totalmente puros, mostra-se como excelente alternativa restauradora, com potencial estético superior às próteses metalocerâmicas. É indiscutível que a tecnologia CAD/CAM (Computer-aided design/ Computer-aided manufacturing) vem se tornando realidade nos consultórios e laboratórios de Prótese Dentária de todo o mundo. Esta tecnologia possibilita o uso de cerâmicas e polímeros na fabricação de próteses, com qualidade e resistência mecânica satisfatórias, padronizando os processos, reduzindo custos e tempo clínico-laboratorial. A grande diversidade destes novos materiais restauradores livres de metal, com suas distintas propriedades estéticas e mecânicas, faz com que seja necessária uma seleção racional desses materiais, a fim de se alcançar a longevidade desejada do tratamento protético reabilitador. Dentre estes materiais, destacam-se as cerâmicas vítreas, as zircônias monolíticas, as cerâmicas infiltradas por polímeros e as resinas nanocerâmicas. O objetivo do trabalho foi avaliar os dados mais relevantes e atuais sobre as propriedades destes novos materiais, os sistemas disponíveis, suas indicações, limitações e seu uso associado com a tecnologia CAD/CAM. Esta revisão consistiu em uma pesquisa eletrônica da literatura publicada nos últimos 15 anos, nas bases de dados: Medline/Pubmed, Embase, Scielo, Bireme, Lilacs e BBO, utilizando-se os seguintes descritores do MESH: [CADCAM AND restorative materials AND monolitic] OR [Monolitic CAD-CAM restorative materials]. Concluiu-se que os materiais monolíticos obtidos pelo sistema CAD/CAM foram desenvolvidos para oferecer uma melhor adaptação e durabilidade das peças, com ótimas taxas de sobrevida e redução de tempo clínico e laboratorial, oferecendo ao paciente conforto, sessões clínicas mais curtas e restaurações de qualidade superior aos sistemas convencionais. Todos os materiais citados nesta revisão apresentaram vantagens e desvantagens, cabendo ao profissional selecionar o melhor material para cada situação clínica em específico, levando em conta os prós e contras de cada um(AU)

The naturalness of restorative procedures in oral rehabilitation has contributed to the development of various types of metal-free materials ("metal free"). The manufacture of prostheses with these totally pure systems is shown to be an excellent restorative alternative, with an aesthetic potential superior to metal-ceramic prostheses. It is indisputable that CAD/ CAM (Computer-aided design/Computer-aided manufacturing) technology is becoming a reality in dental practices and laboratories around the world. This possibility of manufacturing ceramic materials and polymers in strength manufacturing, with strength technology, manufacturing processes, standardizing quality clinical time, higher cost and clinical time. These new aesthetic properties of metal, these dif ferences with aesthetic and mechanical characteristics, these differences are necessary for a rational selection of materials with a choice of rehabilitative prosthetic treatment. Among these materials, they stand out as glass ceramics, as monolithic zirconia, as polymer-infiltrated ceramics and as nanoceramic resins. The purpose of working with your materials, and their associated use with CAD/CAM technology. This review consists of an electronic search of the literature published in the last 15 years, in the following databases: Medline/ Pubmed, Embase, Scielo, Bireme, Lilacs and BBO, using the following MESH descriptors: [CAD-CAM AND restorative materials AND monolithic] OR [CADCAM monolithic restorative materials]. It is concluded that the CAD/CAM materials were designed with comfort for a better adaptation and durability of the parts, with excellent survival rates and reduction of clinical and laboratory time, offering the patient, shorter clinical sessions and superior quality restorations to the systems conventional. All those mentioned in this review present advantages and advantages of each material, and it is up to the professional to select the best one for each specific clinic, in each situation of materials and against indications of materials(AU)

Effect of nanoscale particles incorporation on microhardness of polymers for oral prosthesis.

OBJECTIVES: This study aimed to evaluate the influence of the incorporation of pigments on surface hardness of four acrylic resins subjected to thermocycling and analyze their elemental composition using energy dispersive X-ray spectroscopy (EDS). MATERIALS AND METHODS: Twenty-one discs of each resin were fabricated, whereas seven had no additive, seven had 3% of nanoscale pigments and last seven had 10% of them. The percentage was obtained by measuring the total weight of each resin disc. Besides, seven discs composed by only nanoscale pigments were also fabricated, totalizing 91 discs. The pigment was weighed by using an analytical balance (BEL Analytical Equipment, SP, Brazil). The surface hardness was measured through a hardness tester machine before and after thermocycling (5-55°C, for 2000 cycles). Data were analyzed by ANOVA and Tukey's test (P < 0.05). The chemical composition of the discs composed only by nanoscale pigments was analyzed with EDS test. RESULTS: Hardness of all resins decreased after thermocycling. The lowest values were observed on the discs with 3% of nanoscale pigments and discs fabricated only with them. EDS showed the presence of titanium dioxide. CONCLUSION: Discs with 7% of pigments (after thermocycling) showed higher hardness values.

Epidemiological Data and Survival Rate of Removable Partial Dentures.

INTRODUCTION: The use of removable partial denture (RPD) is considered as low-cost and common treatment option to rehabilitate edentulous areas. AIM: This study aimed to investigate the epidemiological data of patients rehabilitated with removable partial denture (RPD) in order to assess treatment survival rate and failures. MATERIALS AND METHODS: Epidemiological data and medical records of patients treated with RPD between 2007 and 2012 at the RPD discipline of a Brazilian University (Aracatuba Dental School- UNESP) were evaluated as well as dental records of patients who underwent RPD treatments (fabrication or repairs) between 2000 and 2010. Factors such as gender, age, presence of systemic disease, main complaint, edentulous arch, period and cause of denture replacement and the prosthesis characteristics were recorded. The chi-square test was used to assess the differences between the variables and the Kaplan Meyer to assess the survival of the RPDs evaluated. RESULTS: A total of 324 maxillary RPD and 432 mandibular RPD were fabricated. Most of the patients were women aging 41 to 60-year-old. The number of mandibular RPD Kennedy class I (26%) was statistically higher for the maxillary arch (p<.05). There was no association between main complaint to gender or the presence of systemic disease. The lingual plate was the most common major connector used in the mandible (32%). The main reason for altering the design of replaced RPDs were changes during treatment plan. CONCLUSION: The number of patients who require RPD is large; most of RPDs are Kennedy Class I. A good treatment plan is very important for achieving a positive treatment outcome, and it is strictly related to the survival rate.

In vitro analysis of different properties of acrylic resins for ocular prosthesis submitted to accelerated aging with or without photopolymerized glaze.

The effect of a photopolymerized glaze on different properties of acrylic resin (AR) for ocular prostheses submitted to accelerated aging was investigated. Forty discs were divided into 4 groups: N1 AR without glaze (G1); colorless AR without glaze (G2); N1 AR with glaze (G3); and colorless AR with glaze (G4). All samples were polished with sandpaper (240, 600 and 800-grit). In G1 and G2, a 1200-grit sandpaper was also used. In G3 and G4, samples were coated with MegaSeal glaze. Property analysis of color stability, microhardness, roughness, and surface energy, and assays of atomic force microscopy, scanning electron microscopy, and energy-dispersive spectroscopy were performed before and after the accelerated aging (1008h). Data were submitted to the ANOVA and Tukey Test (p<0.05). Groups with glaze exhibited statistically higher color change and roughness after aging. The surface microhardness significantly decreased in groups with glaze and increased in groups without glaze. The surface energy increased after the aging, independent of the polishing procedure. All groups showed an increase of surface irregularities. Photopolymerized glaze is an inadequate surface treatment for AR for ocular prostheses and it affected the color stability, roughness, and microhardness. The accelerated aging interfered negatively with the properties of resins.