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This study evaluated in vitro the biologic profile of manually polished surfaces of pressed lithium disilicate (LD) ceramic compared to zirconia (Zir) in human gingival fibroblasts. Samples with a 10-mm diameter and 3-mm thickness were used. After manual polishing, the average roughness (Ra) of the samples was measured. The cell proliferation and viability of gingival fibroblasts on the surfaces were assessed at 24, 48, and 96 hours. Additionally, the morphology, cell adhesion, and type III collagen (COLIII) and vimentin (VIM) expression by fibroblasts plated onto these surfaces was analyzed. Polystyrene (Pol) was used as control for all assays. The mean Ra was 0.261 ± 0.053 μm for Zir and 0.345 ± 0.130 μm for LD. Both surfaces presented similar cell proliferation and viability (P.05). The cell morphology demonstrated that, for both surfaces, the cells were occasionally spindle-shaped, parallel to the direction of the grooves. Compared to Pol, an upregulation of COLIII and VIM gene expression was observed by fibroblasts cultured on Zir and LD at all time points (P.05). The characteristics presented by LD and Zir surfaces after manual polishing protocol were similar and had biologically favorable performances, thus suggesting LD as a suitable alternative to Zir in the peri-implant region for esthetic purposes.

Made available in DSpace on 2021-06-25T10:50:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 The objective of this study was to assess the resorption index of particulate calvarial grafts in maxillary sinuses of patients undergoing total reconstruction of an atrophic maxilla with residual alveolar bone that was less than, or equal to, 3 mm thick. Twenty-one maxillary sinus floor elevations were carried out using particulate calvarial grafts in 11 individuals with totally edentulous maxillas. All patients had computed tomography (CT) before (T0), and 48 hours (T1) and six months after surgery (T2). For each CT scan, linear measurements were taken of sections of the anterior, medial, and posterior regions of the maxillary sinus. There was a significant increase in the height of the maxillary sinus floor when T0 was compared with T1 (p = 0.001). There was a statistically significant reduction in all maxillary sinus measurements when T1 was compared with T2; the mean height reduction being 2.36 mm (16.87%) in the anterior region, 3.53 mm (22.47%) in the medial region, and 2.21 mm (22.78%) in the posterior region (p = 0.001). Mean resorption was 20.7%. Autogenous calvarial bone used alone is an option for graft material in pneumatised maxillary sinuses and in cases where there is limited alveolar bone. Department of Surgery and Integrated Clinic Araçatuba School of Dentistry – UNESP São Leopoldo Mandic Postgraduate Center Bauru School of Dentistry University of São Paulo – USP Department of Surgery and Integrated Clinic Araçatuba School of Dentistry – UNESP

Made available in DSpace on 2020-12-12T01:46:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-02-01 Purpose: This study evaluated the autogenous graft resorption rate in a calvarial block graft in the anterior region of an atrophic maxilla and compared it with the thickness of the remaining ridge. Materials and Methods: Twelve patients were included in the study. They were submitted to cranial calotte graft surgery, and there were 40 blocks in total. The thicknesses of the ridges in the crest, middle and apical regions of the blocks were evaluated by computed tomography scan at the times: preoperative (T0), 48 hours (T1) and 6 months (T2) after the reconstructions. Results: The resorption of the blocks from T1 to T2 was 13.4%. The greatest remodeling occurred in the alveolar bone crest (20.07%), followed by the middle portion (12.28%), and the apical region (9.5%), but the three regions did not significantly differ between times T1 and T2 (crest P =.07, middle P =.124, apical P =.131). Recipient site with the lowest thickness had the greatest resorption rates (up to 2 mm = 17.6%; from 2 to 4 mm = 17.52%) while than those with a thickness greater than 4 mm had a mean resorption of 8.81%. Conclusions: The resorption of the grafts in this study was 13.4%. Higher resorption rates were observed in the alveolar crest areas, where the ridges were less thick. Private practice Specialist in Radiology and Implantodontics Araçatuba Department of Surgery and Integrated Clinic Araçatuba School of Dentistry – UNESP São Leopoldo Mandic Postgraduate Center Bauru School of Dentistry University of São Paulo – USP Department of Surgery and Integrated Clinic Araçatuba School of Dentistry – UNESP

The purpose of this study was to evaluate the preservation of alveolar dimensions in human fresh extraction sockets filled with a composite bovine bone graft by means of design of single-blind randomized clinical trial. Forty participants had monoradicular teeth extracted (one teeth in each participant), and after were randomly divided into 2 groups: individuals whose fresh sockets were filled with the composite heterologous bone graft (Biomaterial Group), or with blood clot (Control Group). After extraction, the fresh sockets were measured at their greatest mesiodistal (MD) and bucco-lingual/palatal (BL/P) distance. Primary closure of the soft tissue was performed with a fibro-mucosal plug. After 120 post-operative days, the re-entry procedure was performed and the largest MD and BL/P measurements were again obtained to calculate the remodeling of the alveolar bone measured in percentage. In the biomaterial group, a percentage reduction of 1.62% and 3.29% in the MD and BL/P dimensions was observed 120 days after the extractions, whereas a reduction of 4.97% and 7.18% in the MD and BL/P dimensions occurred in the control group. There was a statistically significant difference (p

The aim of this study was to assess the stress patterns on the peri-implant zone and residual alveolar ridge in different overdenture attachment system designs by the photoelasticity method. Four attachments systems were tested: O-ring, ERA, Bar-clip, and Bar-clip/O-ring association. The prostheses were loaded with 100 N in five pre-determined points and the photoelastic model was evaluated by a circular polariscope. The anterior load, O-ring, and ERA showed better stress distribution in relation to the bars systems, which presented stress levels surrounding implants. The molar load, Bar-clip/O-ring association, presented the biggest stress concentration on the peri-implant region in relation to the others. When the second molar was loaded, there was a concentration of stress in the alveolar ridge in all situations analyzed. Within the limitation of this “in vitro” study, it could be concluded that there were biomechanical differences among the attachments systems analyzed, principally between isolated and the bars systems. The O-ring showed better stress distribution and the Bar-clip/O-ring showed higher stress concentration.

The purposes of this study were to photoelastically measure the biomechanical behavior of 4 implants retaining different cantilevered bar mandibular overdenture designs and to compare a fixed partial denture (FPD). A photoelastic model of a human edentulous mandible was fabricated, which contained 4 screw-type implants (3.75 × 10 mm) embedded in the parasymphyseal area. An FPD and 3 overdenture designs with the following attachments were evaluated: 3 plastic Hader clips, 1 Hader clip with 2 posterior resilient cap attachments, and 3 ball/O-ring attachments. Vertical occlusal forces of 100 N were applied between the central incisor and unilaterally to the right and left second premolars and second molars. Stresses that developed in the supporting structure were monitored photoelastically and recorded photographically. The results showed that the anterior loading, the overdenture with 3 plastic Hader clips, displayed the largest stress concentration at the medium implant. With premolar loading, the FPD and overdenture with 3 plastic Hader clips displayed the highest stresses to the ipsilateral terminal implant. With molar loading, the overdenture with 3 ball/O-ring attachments displayed the most uniform stress distribution in the posterior edentulous ridge, with less overloading in the terminal implant. It was concluded that vertical forces applied to the bar-clip overdenture and FPD created immediate stress patterns of greater magnitude and concentration on the ipsilateral implants, whereas the ball/O-ring attachments transferred minimal stress to the implants. The increased cantilever in the FPD caused the highest stresses to the terminal implant.

During the process of facial rehabilitation, the mobility of ocular prostheses must be considered. Whereas some factors depend exclusively on the dentist, such as molding techniques and selection of material for denture construction, regarding ocular rehabilitation, factors, such as type of surgery, whether to adopt implants, and the use of lubricants, deserve special attention owing to their integration and their association with other factors pertaining exclusively to the patient. To establish harmony, and with the intention of aiding the dentist, after a discerning evaluation, the authors of this study report the factors that provide greater or less mobility to ocular prostheses and conceal the prosthesis in a more natural way, thereby contributing toward achieving a favorable aesthetic result in rehabilitations.

This study investigated the efficacy of different techniques for the union of fragments of a denture before repair and on the accuracy of the reposition.For this study, 20 maxillary dentures made with Lucitone 550 heat-cured resin were used. Points were determined with a scanner on the cusp of the teeth, as a measurement of the segments. After digitisation, each model was exported to the AUTOCAD R 14 program and two-dimensional measurements of the distances between the marked points were made. After the initial analysis, the dentures were fractured into two segments using an impact test machine. For the repair, maxillary dentures were divided into two groups; in the first, the repair was carried out using Kerr's sticky wax and in the second group, Super Bonder was used to join the fragments, with subsequent inclusion of DENTSPLY Repair Material resin. After the repair, the points of the maxillary dentures were measured again. The numerical values obtained were tabulated to compare the measurements before fracture and after the repair. For statistical analysis, analysis of variance was employed, using a single factor and double factor, followed by the Tukey test with a reliability of 95%.The results demonstrated a statistically significant difference between the materials used to join the dentures for repair, where the dentures were joined with sticky wax presented a larger variation in the distances between the points.The variation in distances between the points is influenced by the agent of repair.

Purpose: The purpose of this study was to compare the artificial tooth positional changes following the flasking and polymerization of complete dentures by a combination of two flasking methods and two polymerization techniques using computer graphic measurements. Materials and Methods: Four groups of waxed complete dentures (n = 10) were invested and polymerized using the following techniques: (1) adding a second investment layer of gypsum and conventional water bath polymerization (Control), (2) adding a second investment layer of gypsum and polymerization with microwave energy (Gypmicro), (3) adding a second investment layer of silicone (Zetalabor) and conventional polymerization (Silwater), and (4) adding a second investment layer of silicone and polymerization with microwave energy (Silmicro). For each specimen, six segments of interdental distances (A to F) were measured to determine the artificial tooth positions in the waxed and polymerized stages using software program AutoCad R14. The mean values of the changes were statistically compared by univariate ANOVA with Tukey post-hoc test at 5% significance. Results: There were no significant differences among the four groups, except for segment D of the Silmicro group (−0.004 ± 0.032 cm) in relation to the Gypwater group (0.044 ± 0.031 cm) (p < 0.05), which presented, repectively, expansion and shrinkage after polymerization. Conclusions: Within the limitations of this study, it was concluded that although the differences were not statistically significant, the use of a silicone investment layer when flasking complete dentures resulted in the least positional changes of the artificial teeth regardless of the polymerization technique.

The consequences as well the criteria for the prosthetic oral rehabilitations with tooth/implant connection come in the literature, in most of the cases, with controversial results. On one side, many studies consider the connection viable, while the others studies consider impracticable because of the difference biomechanics and physiologic of the two systems. The purpose of this study was to organize, to synthesize and to select literary studies that can standardize solutions when this rehabilitation type is necessary. The study showed that the clinical follow-up result in a high survival rate in a short period and the bioengineering studies did not accept the tooth/implant connection.

Made available in DSpace on 2015-08-26T19:19:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-06-01. Added 1 bitstream(s) on 2015-08-31T13:04:53Z : No. of bitstreams: 1 S0103-64402015000300284.pdf: 361947 bytes, checksum: c507898e9e30a04f581c1934b7e0b57b (MD5) Este estudo in vitro avaliou o efeito da ciclagem mecânica no torque dos parafusos de retenção em implantes de hexágono externo com plataforma switching (PS), plataforma regular (RP) e plataforma larga (WP). Foram utilizados 30 corpos de prova divididos em 3 grupos equitativamente: PS, RP e WP. Cada corpo de prova foi preparado com implantes: 3,75x10 mm para o grupo RP e 5,0x10 mm para os grupos PS e WP, e seu respectivo abutment com o torque de 32 Ncm. Todos os grupos foram submetidos a 106 ciclos com 100 N de força (o que corresponde a aproximadamente 40 meses de mastigação). Os resultados foram obtidos com o torque reverso de cada espécime e os dados foram avaliados com ANOVA comparado com o teste de Tukey (p

The aim of this in vitro study was to evaluate the mechanical behavior and bacterial microleakage at the implant/abutment-tapered interface following mechanical cycling. Two groups of screwless (Morse taper) implants (G1 and G2) and two groups of prosthetic screwed implants (G3 and G4) were tested. One group from each model (G2 and G4) were submitted to mechanical cycling, 500,000 cycles per sample, at a load of 120 N at 2 Hz prior to analysis. Microbiological analysis was performed via immersion of all samples in an Escherichia coli-containing suspension, incubated at 37 °C. After 14 days, the abutments were removed from their respective implants, registering the removal force (G1 and G2) or reverse torque (G3 and G4), and the presence of bacterial leakage was evaluated. Scanning electron microscopy (SEM) was performed to analyze the tapered surfaces of the selected samples. The Student t, binomial, and G tests were used for statistical analysis at a 5 % significance level. The results showed no significant difference between removal force, reverse torque, and contamination values when comparing implants of the same type. However, when the four groups were compared, contamination differed significantly (p = 0.044), with G1 having the least number of contaminated samples (8.3 %). SEM analysis showed superficial defects and damage. The abutment removal force or torque was not affected by mechanical cycling. Bacterial sealing of the implant/abutment tapered interface was not effective for any condition analyzed. Imprecise machining of implant parts does not allow a sufficient contact area between surfaces to provide effective sealing and prevent bacterial leakage. The microscopic gap caused by unsatisfactory implant/abutment adaptation, surface irregularities, and plastic deformation of all parts enabled bacterial contamination of the oral implants.

The purpose of this study was to compare the dental movement that occurs during the processing of maxillary complete dentures with 3 different base thicknesses, using 2 investment methods, and microwave polymerization.A sample of 42 denture models was randomly divided into 6 groups (n = 7), with base thicknesses of 1.25, 2.50, and 3.75 mm and gypsum or silicone flask investment. Points were demarcated on the distal surface of the second molars and on the back of the gypsum cast at the alveolar ridge level to allow linear and angular measurement using AutoCAD software. The data were subjected to analysis of variance with double factor, Tukey test and Fisher (post hoc).Angular analysis of the varying methods and their interactions generated a statistical difference (P = 0.023) when the magnitudes of molar inclination were compared. Tooth movement was greater for thin-based prostheses, 1.25 mm (-0.234), versus thick 3.75 mm (0.2395), with antagonistic behavior. Prosthesis investment with silicone (0.053) showed greater vertical change compared with the gypsum investment (0.032). There was a difference between the point of analysis, demonstrating that the changes were not symmetric.All groups evaluated showed change in the position of artificial teeth after processing. The complete denture with a thin base (1.25 mm) and silicone investment showed the worst results, whereas intermediate thickness (2.50 mm) was demonstrated to be ideal for the denture base.

O propósito desse trabalho foi investigar a movimentação dentária que ocorre durante o processamento de prótesestotais superiores, avaliando a posição relativa dos dentes artificiais das dentaduras quando incluídas comtrês diferentes métodos e submetidas à polimerização por banho de água quente. Dezoito dentaduras superioresforam confeccionadas e separadas em três grupos de seis espécimes de acordo com o tipo de inclusão; com gessopedra tipo III, com muralha de silicone ou com muralha de gesso especial. Para as mensurações das movimentaçõesdentárias utilizou-se um guia de resina acrílica com pontos pré-determinados que permitiam demarcarpontos referência sobre as cúspides dos dentes. Foi utilizado o software AutoCad R14 para a tomada das medidasentre os pontos. Os nossos resultados nos permitiram concluir que: a) todos os grupos estudados sofreramalterações em maior ou menor grau, b) a inclusão pelo método da muralha de gesso especial mostrou-se commenores alterações quando comparadas com a inclusão em gesso pedra e muralha de silicone, c) o triângulomaior formado pelos segmentos A (molar-molar), B (molar-incisivo) e F (incisivo-molar) foi o que sofreu maioresalterações.

Empiricamente, tem-se utilizado o alisamento do alginato com o dedo umedecido após o carregamento da moldeira, com a justificativa, de se obter moldes com número reduzido de bolhas e irregularidades, fato que tem sido observado por alguns autores, sem saber no entanto, se existe diferença entre essas técnicas no que diz respeito às diferentes formulações de alginato. Assim, o propósito desse estudo foi avaliar a presença de bolhas superficiais de 3 marcas de alginato, quando submetidas à duas técnicas de moldagem; com carregamento convencional com a espátula e com o carregamento seguido do alisamento com dedo umedecido em água. Foi confeccionada uma matriz em resina acrílica, representando um maxilar edêntulo cujo palato foi ligeiramente modificado a fim de apresentar superfície plana. O estudo foi dividido em 6 grupos de acordo com a técnica de moldagem e com o material utilizado (Jeltrate, Jeltrate Plus e Hidrogum), consistindo em dez moldes para cada grupo. Após a realização da moldagem, a região do palato foi analisada em lupa (50 vezes), permitindo a contagem das bolhas, sendo os dados tabulados e submetidos ao tratamento estatístico da análise de variância e teste de Tukey com nível de significância a 5%. Os resultados permitiram concluir que: a presença de bolhas foi significantemente superior (p

Em função da introdução de novas marcas comerciais de materiais odontológicos e se existe diferença na aplicação desses materiais, o propósito desse estudo foi o de avaliar a influência de diferentes materiais de inclusão de próteses totais superiores através da análise da movimentação dos dentes artificiais. Para tanto foram confeccionadas quarenta próteses totais superiores, com semelhanças dimensionais, através de um gabarito padrão. Essas próteses foram divididas em quatro grupos com dez espécimes cada, de acordo com o tipo de resina para inclusão (Vipwave; Ondacryl) e o tipo de silicone (Zetalabor; Vip-sil) utilizado no revestimento. Foram demarcados pontos sobre os dentes, que serviram de referência para as mensurações dos segmentos (entre os dentes), através do software AutoCad 2000. As mensurações foram realizadas em três momentos: após o enceramento; após a demuflagem e após a separação do modelo. Os resultados foram submetidos à análise de variância e ao teste de Tukey com probabilidade de 5%. Os resultados permitiram concluir que: Todos os grupos estudados sofreram alterações com um comportamento semelhante, quando se avaliou a contração de polimerização após a demuflagem, não encontrando diferenças entre os grupos (p

O propósito desse estudo foi o de verificar a influência do polimento sobre a posição relativa dos dentes artificiais de próteses totais superiores, quando essas são confeccionadas com diferentes tipos de materiais ou associações, analisando para tanto à diferença entre as distâncias dos dentes pelo método de computação gráfica. Foram confeccionadas quarenta próteses totais superiores idênticas, sendo divididas em oito grupos de cinco espécimes cada de acordo com o tipo de resina (Vipi-wave e Onda-cryl), tipo de silicone para inclusão (Vipi-sil e Zetalabor) e tipo de polimento. As próteses foram polimerizadas em microondas, demufladas e submetidas ao polimento químico e ao polimento mecânico. Em cada fase as próteses foram digitalizadas em scanner de mesa e suas imagens exportadas para o software AutoCad 2000 que possibilitou a mensuração dos segmentos entre os pontos previamente demarcados nos dentes. Os dados foram submetidos ao tratamento estatístico, e os resultados possibilitaram concluir que o polimento físico resultou em alterações significantemente superiores ao polimento químico quando os dados foram analisados independentemente do grupo estudado (p

The technique presented in this article presents a protocol for treatment that reduces the time required for the fabrication and placement of an implant supported prosthesis. It also offers improved patient comfort at a lower cost when compared to conventional technology.

The aim of this study was to compare splinting techniques for impression copings of osseointegrated implants with different angulations.Replicas (N = 24) of a metal matrix (control) containing two implants at 90 degrees and 65 degrees in relation to the horizontal surface were obtained by using four impression techniques: Technique 1 (T1), direct technique with square copings without union in open trays; Technique 2 (T2), square copings splinted with dental floss and autopolymerizing acrylic resin; Technique 3 (T3),square copings splinted with dental floss and autopolymerizing acrylic resin, sectioned and splinted again with autopolymerizing acrylic resin; Technique 4 (T4), square copings splinted with prefabricated acrylic resin bar. The impression material was polyether. The replicas were individually scanned to capture the images, which were assessed in a graphic computation program. The program allowed the angulation between the bases of the replicas and the reading screws to be measured. The images of the replicas were compared with the matrix image (control), and the differences in angulations from the control image were calculated. The analysis of variance and the Tukey test for comparisons (p0.05) were used for statistical analysis.All groups showed significant differences in the implant angulations in comparison with the control group (p0.05). Group T1 showed the highest difference (1.019 degrees ) followed by groups T2 (0.747 degrees ), T3 (0.516 degrees ), and T4 (0.325 degrees ), which showed the lowest angular alteration compared to the control group. There were significant differences between inclined and straight implants in all the groups, except in group T4.Based on the results, the splinting of pick-up impression copings is indicated for osseointegrated implant impressions. The square copings splinted with a prefabricated acrylic resin bar presented the best results among the pick-up impression techniques evaluated in this study.

El objetivo del estudio fue evaluar la presencia de burbujas superficiales y la alteracion dimensional en los modelos obtenidos de impresiones de alginato, con y sin alisamiento con el dedo humedecido en agua, Se hizo una matriz en resina acrilica del maxilar desdentado cuyo paladar se modifico para que presentara una superficie llana y lisa y se insertaron S pernos metalicos en la cresta del reborde en lugares predeterminados, El estudio se dividio en 6 grupos de acuerdo con la tecnica de impresion y del material usado Ueltrate, Jeltrate plus e Hidrogum), con un total de 10 modelos para cada grupo, El paladar de los modelos se valoro con lupa (SO aumentos) lo que permitio la estimacion de ias burbujas, La lectura de los modelos se hizo por digitalizacion de los modelos, midiendo la distancia entre los pernos con el software AutoCAD 2000, Los datos segun el analisis de la varianza (ANOV A) y el test de Tukey (S%) indicaron una reduccion significativa en el porcentaje de burbujas cuando se hacia el alisa miento, Los modelos donde se hizo el alisamiento presentara/' alteraciones sin diferencias estadistica mente significativas respecto a los grupos donde no se hizo el alisamiento, El analisis de los resultados permitio concluir que el alisa miento del alginato con el dedo humedecido no afecto la precision de los modelos del yeso en ningunos de los alginatos probados, El alisado dio lugar a una reduccion significativa en el numero de burbujas superficiales.