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1.
Pharmaceutics ; 14(7)2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35890413

RESUMO

Dentures and epitheses are mostly made from poly(methyl methacrylate) (PMMA), which does not show antimicrobial properties. They present reservoirs of microorganisms grown in biofilms. The aim of this study is to prepare a PMMA enriched with gold nanoparticles (AuNPs)-PMMA/AuNPs and the examination of its physical, mechanical and antimicrobial properties. The AuNPS were synthetized from HAuCl4 using the ultrasonic spray pyrolysis method with lyophilization. The PMMA/AuNP samples were compared to PMMA samples. Density was measured by pycnometer. Microhardness was evaluated using the Vickers hardness test. Monomicrobial biofilm formation (Streptococcus mitis, Candida albicans, Staphylococcus aureus and Escherichia coli) was measured by colony-forming units (CFUs) and MTT test and visualized by SEM. AuNP release was measured indirectly (the CFUs of the medium around the sample). The density and microhardness of the PMMA/AuNPs were similar to those of the PMMA. CFU and MTT values for the biofilms formed on the PMMA for each of the tested species were higher than those of the biofilms formed on the PMMA/AuNPs. The CFUs of the medium around the sample were similar for both materials. PMMA/AuNPs showed a significant reduction in the monomicrobial biofilms of all tested species. AuNPs are not released from PMMA/AuNPs. Density, indirect measurement of residual monomer and dentures weight were similar between PMMA and PMMA/AuNPs. Microhardness, as a measure of the wear resistance, was also similar between tested discs.

2.
Molecules ; 27(6)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35335323

RESUMO

Nickel-titanium alloys used in dentistry have a variety of mechanical, chemical, and biofunctional properties that are dependent on the manufacturing process. The aim of this study was to compare the mechanical and biofunctional performances of a nickel-titanium alloy produced by the continuous casting method (NiTi-2) with commercial nitinol (NiTi-1) manufactured by the classical process, i.e., from remelting in a vacuum furnace with electro-resistive heating and final casting into ingots. The chemical composition of the tested samples was analyzed using an energy dispersive X-ray analysis (EDX) and X-ray fluorescence (XRF). Electron backscatter diffraction (EBSD) quantitative microstructural analysis was performed to determine phase distribution in the samples. As part of the mechanical properties, the hardness on the surface of samples was measured with the static Vickers method. The release of metal ions (Ni, Ti) in artificial saliva (pH 6.5) and lactic acid (pH 2.3) was measured using a static immersion test. Finally, the resulting corrosion layer was revealed by means of a scanning electron microscope (SEM), which allows the detection and direct measurement of the formatted oxide layer thickness. To assess the biocompatibility of the tested nickel-titanium alloy samples, an MTT test of fibroblast cellular proliferation on direct contact with the samples was performed. The obtained data were analyzed with the IBM SPSS Statistics v22 software. EDX and XRF analyses showed a higher presence of Ni in the NiTi-2 sample. The EBSD analysis detected an additional NiTi2-cubic phase in the NiTi-2 microstructure. Additionally, in the NiTi-2 higher hardness was measured. An immersion test performed in artificial saliva after 7 days did not induce significant ion release in either group of samples (NiTi-1 and NiTi-2). The acidic environment significantly increased the release of toxic ions in both types of samples. However, Ni ion release was two times lower, and Ti ion release was three times lower from NiTi-2 than from NiTi-1. Comparison of the cells' mitochondrial activity between the NiTi-1 and NiTi-2 groups did not show a statistically significant difference. In conclusion, we obtained an alloy of small diameter with an appropriate microstructure and better response compared to classic NiTi material. Thus, it appears from the present study that the continuous cast technology offers new possibilities for the production of NiTi material for usage in dentistry.


Assuntos
Níquel , Titânio , Teste de Materiais , Níquel/química , Propriedades de Superfície , Titânio/química
3.
Materials (Basel) ; 13(12)2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32549247

RESUMO

In this research work, we synthesised poly(methyl methacrylate) (PMMA) enriched with 2 wt.% zinc oxide nanoparticles (ZnO) through conventional heat polymerisation and characterised its microstructure. It was found that the distribution of ZnO nanoparticles was homogeneous through the volume of the PMMA. The mechanical testing of the PMMA-ZnO composite primarily included the determination of the compressive properties on real dentures, while density measurements were performed using a pycnometer. The testing of functional properties involved the identification of the colour of the new PMMA-ZnO composite, where pure PMMA acted as a control. In the second step, the PMMA-ZnO cytotoxicity assays were measured in vitro, which were shown to be similar to the control PMMA. Based on this, it could be concluded that the newly formed PMMA-ZnO composite did not induce direct or indirect cytotoxic effects in L929 cell cultures; therefore, according to ISO/DIN 10993-5:2009, this composite was categorised as non-cytotoxic.

4.
PLoS One ; 12(2): e0171296, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28166255

RESUMO

BACKGROUND: Psychological discomfort, physical disability and functional limitations of the orofacial system have a major impact on everyday life of patients with temporomandibular disorders (TMDs). In this study we sought to determine short and long term effects of stabilization splint (SS) in treatment of TMDs, and to identify factors influencing its efficacy. METHODS: MEDLINE, Web of Science and EMBASE were searched for randomized controlled trials (RCTs) comparing SS to: non-occluding splint, occlusal oral appliances, physiotherapy, behavioral therapy, counseling and no treatment. Random effects method was used to summarize outcomes. The effect estimates were expressed as odds ratio (OR) or standardized mean difference (SMD) with 95% confidence interval. Subgroup analyses were carried out according to the use of Research Diagnostic Criteria (RDC/TMD) and TMDs origin. Strength of evidence was assessed by GRADE. Meta-regression was applied. RESULTS: Thirty three eligible RCTs were included in meta-analysis. In short term, SS presented positive overall effect on pain reduction (OR 2.08; p = 0.01) and pain intensity (SMD -0.33; p = 0.02). Subgroup analyses confirmed SS effect in studies used RDC/TMD and revealed its effect in patients with TMDs of muscular origin. Important decrease of muscle tenderness (OR 1.97; p = 0.03) and improvement of mouth opening (SMD -0.30; p = 0.04) were found. SS in comparison to oral appliances showed no difference (OR 0.74; p = 0.24). Meta-regression identified continuous use of SS during the day as a factor influencing efficacy (p = 0.01). Long term results showed no difference in observed outcomes between groups. Low quality of evidence was found for primary outcomes. CONCLUSION: SS presented short term benefit for patients with TMDs. In long term follow up, the effect is equalized with other therapeutic modalities. Further studies based on appropriate use of standardized criteria for patient recruitment and outcomes under assessment are needed to better define SS effect persistence in long term.


Assuntos
Placas Oclusais , Transtornos da Articulação Temporomandibular/terapia , Seguimentos , Humanos , Razão de Chances , Fatores de Tempo , Resultado do Tratamento
5.
J Craniofac Surg ; 27(2): e185-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26854784

RESUMO

Implant stability is a principal precondition for the success of implant therapy. Extraoral implants (EO) are mainly used for anchoring of maxillofacial epithesis. However, assessment of implant stability is mostly based on principles derived from oral implants. The aim of this study was to investigate clinical stability of EO craniofacial disk implants (single, double, and triple) by resonance frequency analysis at different stages of the bone's healing. Twenty patients with orbital (11), nasal (5), and auricular (4) defects with 50 EO implants placed for epithesis anchorage were included. Implant stability was measured 3 times; after implant placement, at 3 months and at least after 6 months. A significant increase in implant stability values was noted between all of the measurements, except for triple-disk implants between third and sixth months, and screw implants between 0 and third months. Disk implants showed lower implant stability quotient (ISQ) values compared with screw implants. Triple-disk implants showed better stability compared with single and double-disk implants. Based on resonance frequency analysis values, disk implants could be safely loaded when their ISQ values are 38 (single disks), 47 (double disks), and 48 (triple disks). According to resonance frequency analysis, disk implant stability increased over time, which showed good osseointegration and increasing mineralization. Although EO screw implants showed higher ISQ values than disk implants, disk-type implants can be safely loaded even if lower values of stability are measured.


Assuntos
Ossos Faciais/cirurgia , Osseointegração/fisiologia , Implantação de Prótese/métodos , Parafusos Ósseos , Remoção de Dispositivo , Orelha Externa , Seguimentos , Humanos , Osso Nasal/cirurgia , Órbita/cirurgia , Osteotomia/instrumentação , Osso Petroso/cirurgia , Estudos Prospectivos , Desenho de Prótese , Retenção da Prótese , Transdutores , Vibração
6.
J Oral Facial Pain Headache ; 29(3): 279-85, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26244436

RESUMO

AIMS: To investigate the potential role of polymorphisms in matrix metalloproteinase-9 (MMP-9), glutathione S-transferase M1 (GSTM1) and T1 (GSTT1), and methylenetetrahydrofolate reductase (MTHFR) genes as risk factors for development of temporomandibular disorders (TMD) in a Serbian population. METHODS: This case-control study included 282 subjects: 100 with TMD and 182 healthy controls. Genotyping was done by means of polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP) for single nucleotide polymorphisms (SNPs) analysis (C-1562T MMP-9 and C677T MTHFR) or multiplex PCR and real-time PCR methods for deletion analysis (GSTM1, GSTT1) of DNA obtained from buccal swabs. The association of gene variants with TMD risk was determined by calculating odds ratios (OR) and their 95% confidence intervals (CI). RESULTS: A statistically significant difference in genotype and allele frequencies was found between the TMD group and controls for the MMP-9 SNP. Heterozygotes (CT) were significantly more frequent in the TMD group than in the control group and carriers of the T allele had an approximately twofold increase of TMD risk (OR = 2.13, 95% CI = 1.24-3.67, P = .005). The null GSTT1 genotype as well as the combined non-null GSTM1/ null GSTT1 were associated with lower risk of TMD (OR = 0.28, CI = 0.10-0.74, P = .004 and OR = 0.16, CI = 0.03-0.58, P < .001, respectively). GSTM1 alone and MTHFR polymorphisms did not show an association with TMD. CONCLUSION: The C-1562T SNP in the promoter region of the MMP-9 gene, the GSTT1 null, as well as the combined GSTM1 non-null and GSTT1 null genotypes are modulators of TMD risk in a Serbian population.


Assuntos
Glutationa Transferase/genética , Metaloproteinase 9 da Matriz/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo Genético , Transtornos da Articulação Temporomandibular/genética , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Masculino
8.
Srp Arh Celok Lek ; 142(3-4): 150-4, 2014.
Artigo em Sérvio | MEDLINE | ID: mdl-24839768

RESUMO

INTRODUCTION: Patients with craniomandibular disorders suffer from hypertonic, fatigued and painful masticatory muscles.This condition can lead to limitation of mandibular jaw movements. All of these symptoms and signs are included in myofascial pain dysfunction syndrome.Transcutaneous electrical nerve stimulation (TENS) has been used for treatment of these patients. OBJECTIVE: The aim of this study was to assess the effect ofTENS therapy on chronic pain reduction in patients with the muscular dysfunction symptom. METHODS: In order to evaluate the effect ofTENS therapy before and after the treatment, Craniomandibular Index (Helkimo) was used. Pain intensity was measured by VAS. Patients had TENS treatment over two-week period. BURST TENS modality was used. Current intensity was individually adjusted. RESULTS: Two patients did not respond to TENS therapy. Complete pain reduction was recorded in 8 patients, while pain reduction was not significantly different after TENS therapy in 10 patients. CONCLUSION: TENS therapy was confirmed as therapeutic procedure in orofacial muscle relaxation and pain reduction.


Assuntos
Dor Crônica/terapia , Dor Facial/terapia , Estimulação Elétrica Nervosa Transcutânea , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor/métodos , Síndrome , Estimulação Elétrica Nervosa Transcutânea/instrumentação , Estimulação Elétrica Nervosa Transcutânea/métodos , Adulto Jovem
9.
Vojnosanit Pregl ; 71(3): 251-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24697011

RESUMO

BACKGROUND/AIM: Dimensional stability and accuracy of an impression after chemical disinfection by immersion in disinfectants are crucial for the accuracy of final prosthetic restorations. The aim of this study was to assess the deformation of addition and condensation silicone impressions after disinfection in antimicrobial solutions. METHODS: A total of 120 impressions were made on the model of the upper arch representing three full metal-ceramic crown preparations. Four impression materials were used: two condensation silicones (Oranwash L - Zhermack and Xantopren L Blue - Heraeus Kulzer) and two addition silicones (Elite H-D + regular body - Zhermack and Flexitime correct flow - Heraeus Kulzer). After removal from the model the impressions were immediatel immersed in appropriate disinfectant (glutaraldehyde, benzalkonium chloride - Sterigum and 5.25% NaOC1) for a period of 10 min. The control group consisted of samples that were not treated with disinfectant solution. Consecutive measurements of identical impressions were realized with a Canon G9 (12 megapixels, 2 fps, 6x/24x), and automated with a computer Asus Lamborghini VX-2R Intel C2D 2.4 GHz, by using Remote Capture software package, so that time-depending series of images of the same impression were obtained. RESULTS: The dimensional changes of all the samples were significant both as a function of time and the applied disinfectant. The results show significant differences of the obtained dimensional changes between the group of condensation silicones and the group of addition silicones for the same time, and the same applied disinfectant (p = 0.026, F = 3.95). CONCLUSION: The greatest dimensional changes of addition and condensation silicone impressions appear in the first hour after their separation from the model.


Assuntos
Materiais para Moldagem Odontológica , Técnica de Moldagem Odontológica/instrumentação , Prótese Dentária , Desinfetantes/farmacologia , Desinfecção/métodos , Elastômeros de Silicone , Humanos , Propriedades de Superfície
10.
Vojnosanit Pregl ; 70(10): 929-34, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24313174

RESUMO

BACKGROUND/AIM: Color matching in prosthodontic therapy is a very important task because it influences the esthetic value of dental restorations. Visual shade matching represents the most frequently applied method in clinical practice. Instrumental measurements provide objective and quantified data in color assessment of natural teeth and restorations. In instrumental shade analysis, the goal is to achieve the smallest deltaE value possible, indicating the most accurate shade match. The aim of this study was to evaluate the reliability of commercially available ceramic shade guides. METHODS: VITA Easyshade spectrophotometer (VITA, Germany) was used for instrumental color determination. Utilizing this device, color samples of ten VITA Classical and ten VITA 3D - Master shade guides were analyzed. Each color sample from all shade guides was measured three times and the basic parameters of color quality were examined: deltaL, deltaC, deltaH, deltaE, deltaElc. Based on these parameters spectrophotometer marks the shade matching as good, fair or adjust. RESULTS: After performing 1,248 measurements of ceramic color samples, frequency of evaluations adjust, fair and good were statistically significantly different between VITA Classical and VITA 3D Master shade guides (p = 0.002). There were 27.1% cases scored as adjust, 66.3% as fair and 6.7% as good. In VITA 3D - Master shade guides 30.9% cases were evaluated as adjust, 66.4% as fair and 2.7% cases as good. CONCLUSION: Color samples from different shade guides, produced by the same manufacturer, show variability in basic color parameters, which once again proves the lack of precision and nonuniformity of the conventional method.


Assuntos
Planejamento de Prótese Dentária , Pigmentação em Prótese , Cerâmica/uso terapêutico , Planejamento de Prótese Dentária/métodos , Planejamento de Prótese Dentária/normas , Humanos , Pigmentação em Prótese/métodos , Pigmentação em Prótese/normas , Reprodutibilidade dos Testes , Espectrofotometria/instrumentação , Espectrofotometria/métodos
11.
Vojnosanit Pregl ; 70(1): 80-5, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23401936

RESUMO

INTRODUCTION: Mandible reconstruction is still very challenging for surgeons. Mandible defects could be the consequence of ablative surgery for malignancies, huge jaw cysts, infection and trauma. Segmental resection of the mandible may compromise orofacial function and often lead to patients psychological disorders. Despite very frequent use of microvascular flaps, autogenous bone grafts are still very reliable technique for mandible reconstruction. Comprehensive therapy means not only mandible reconstruction, but prosthodontic rehabilitation supported by dental implants, which can significantly improve patients quality of life. The aim of this paper was to evaluate possible techniques of mandible reconstruction and to present a patient who had been submitted to mandible resection and reconstruction with autogenous iliac bone graft and prosthodontic rehabilitation with fixed denture anchoraged by disc-shaped implants in early loading protocol. CASE REPORT: Mandible reconstruction was performed simultaneously with resection. Autogenous iliac bone graft was taken, reshaped and placed in two parts, to the required optimal contour of the mandible. After graft consolidation, decision was made for prosthodontics rehabilitation with fixed dentures supported by implants. In addition to the standard preoperative procedures, planning was done based on a biomodel gained by rapid prototyping after CT scan. It offered a real 3D planning to obtain a proper shape, dimension and the position of implants. CONCLUSION: If bone dimensions of a reconstructed mandible are insufficient, like in the presented case, the use of basal osseointegrated implants may be a method of choice. Avoiding bone augmentation procedures, as well as early loading protocol for this type of implants, shorten the total rehabilitation time, which is very convenient for patients. Fixed denture supported by dental implants is the best solution for comprehensive rehabilitation after mandible resection.


Assuntos
Transplante Ósseo , Implantação Dentária Endóssea , Osteotomia Mandibular , Reconstrução Mandibular/métodos , Feminino , Humanos , Pessoa de Meia-Idade
12.
Vojnosanit Pregl ; 69(2): 181-9, 2012 Feb.
Artigo em Sérvio | MEDLINE | ID: mdl-22500374

RESUMO

BACKGROUND/AIM: Immediate loading is considered to be the most innovative technique in contemporary implant dentistry. Recent clinical and experimental findings have demonstrated that only implants with high primary stability can be subjected to immediate loading protocol with predictable results. It is generally accepted that the most important prerequsite for successful osseointegration is achievement and maintenance of implant stability. The aim of this in vivo study was to investigate the possibility for successful application of immediate loading protocol in implant systems with different surface properties. METHODS: In the experimental study 2 mongrel dogs were edentulated bilaterally in the mandibular and maxillary premolar areas. After 3 months implants were placed in a pattern 4 different commercially available implants per quadrant (n = 32): Mk III TiUnite (Nobel Biocare, Sweden), ITI TPS (Straumann, Switzerland), 31-Osseotite (Implant Innovation, USA) and XiVE Cell-Plus (Friadent, Germany). Implants were subjected to immediate loading with 4 unit gold cast bridges, 2 days post implantation. The assessment of implant stability and immediate loading possibilities were done by performing Resonance frequency analysis (RFA). RESULTS: After a 6-month loading period all bridges were in function and all implants occurred well osseointegrated. When summarizing the Implant Stability Quotient (ISQ) values, it was noted that resonance frequency was significantly higher for mandibular implants. The results of this experimental setting showed that all evaluated surfaces achieved good implant stability. Increase of ISQ values was found for all implants in the mandible and partially decrease of ISQ values for maxillary implants after 6 months of functional loading with 4 unit bridges. CONCLUSIONS: Investigated endooseal implants did not show different degree of osseointegration, because there was not statisticaly significant difference among observed parameters (ISQh i ISQp) between implant systems.


Assuntos
Implantação Dentária Endóssea , Prótese Parcial Fixa , Osseointegração , Animais , Análise do Estresse Dentário , Retenção de Dentadura , Cães , Feminino
13.
Vojnosanit Pregl ; 67(10): 812-8, 2010 Oct.
Artigo em Sérvio | MEDLINE | ID: mdl-21066873

RESUMO

BACKGROUND/AIM: One of the results of many years of Cerec 3D CAD/CAM system technological development is implementation of one intraoral and two extraoral optical scanning methods which, depending on the current indications, are applied in making fixed restorations. The aim of this study was to determine the degree of precision of optical scanning methods by the use of the Cerec 3D CAD/CAM system in the process of making ceramic inlays. METHODS: The study was conducted in three experimental groups of inlays prepared using the procedure of three methods of scanning Cerec 3D system. Ceramic inlays made by conventional methodology were the control group. The accuracy of optical scanning methods of the Cerec 3D system computer aided design-computer aided manufacturing (CAD/CAM) was indirectly examined by measuring a marginal gap size between inlays and demarcation preparation by scanning electron microscope (SEM). RESULTS: The results of the study showed a difference in the accuracy of the existing methods of scanning dental CAD/CAM systems. The highest level of accuracy was achieved by the extraoral optical superficial scanning technique. The value of marginal gap size inlays made with the technique of extraoral optical superficial scanning was 32.97 +/- 13.17 mus. Techniques of intraoral optical superficial and extraoral point laser scanning showed a lower level of accuracy (40.29 +/- 21.46 mus for inlays of intraoral optical superficial scanning and 99.67 +/- 37.25 mus for inlays of extraoral point laser scanning). CONCLUSION: Optical scanning methods in dental CAM/CAM technologies are precise methods of digitizing the spatial models; application of extraoral optical scanning methods provides the highest precision.


Assuntos
Cerâmica , Desenho Assistido por Computador , Porcelana Dentária , Restaurações Intracoronárias , Tomografia Óptica , Humanos , Restaurações Intracoronárias/métodos , Sensibilidade e Especificidade
14.
J Craniofac Surg ; 21(1): 33-6, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20061980

RESUMO

AIM: To report the case of a patient who underwent facial reconstruction with nasal epithesis anchored on basal (disk) implants after ablation of midface squamous cell carcinoma. METHODS: Ablative surgery of the midface region and insertion of 3 basal implants into the glabellar area of the frontal bone, the upper part of the right side of the alveolar crest, and the lateral side of the maxillary bone, which forms the left lateral wall of the nose, respectively, was performed. Implants were placed at the time of the primary surgical attempt. RESULTS: After an unloaded osseointegration phase of 3 months, all implants appeared well integrated according to radiologic criteria and clinical stability. At the end of the osseointegration process, the final epithesis was delivered. Epithesis was anchored to the bars that were fabricated to provide retention and better stability, whereas the implant on the left side was used individually only to improve stability. At the control examinations after 1, 3, 6, 12, and 18 months, respectively, there were no signs of recurrence of the tumor or any complications related to the implants. CONCLUSIONS: Disk implants that were applied to our patient present an excellent alternative, particularly in cases with minimal available bone, resulting in reduced complications in elderly oncologic patients.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Ossos Faciais/cirurgia , Neoplasias Faciais/cirurgia , Neoplasias Nasais/cirurgia , Próteses e Implantes , Neoplasias Cranianas/cirurgia , Idoso de 80 Anos ou mais , Feminino , Humanos , Osseointegração , Retalhos Cirúrgicos
15.
Acta Biomater ; 6(1): 308-17, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19540942

RESUMO

Cu-Al-Ni shape memory alloys (SMAs) have been investigated as materials for medical devices, but their biomedical application is still limited. The aim of this work was to compare the microstructure, corrosion and cytotoxicity in vitro of a Cu-Al-Ni SMA. Rapidly solidified (RS) thin ribbons, manufactured via melt spinning, were used for the tests. The control alloy was a permanent mould casting of the same composition, but without shape memory effect. The results show that RS ribbons are significantly more resistant to corrosion compared with the control alloy, as judged by the lesser release of Cu and Ni into the conditioning medium. These results correlate with the finding that RS ribbons were not cytotoxic to L929 mouse fibroblasts and rat thymocytes. In addition, the RS ribbon conditioning medium inhibited cellular proliferation and IL-2 production by activated rat splenocytes to a much lesser extent. The inhibitory effects were almost completely abolished by conditioning the RS ribbons in culture medium for 4 weeks. Microstructural analysis showed that RS ribbons are martensitic, with boron particles as a minor phase. In contrast, the control Cu-Al-Ni alloy had a complex multiphase microstructure. Examination of the alloy surfaces after conditioning by energy dispersive X-ray and Auger electron spectroscopy showed the formation of Cu and Al oxide layers and confirmed that the metals in RS ribbons are less susceptible to oxidation and corrosion compared with the control alloy. In conclusion, these results suggest that rapid solidification significantly improves the corrosion stability and biocompatibility in vitro of Cu-Al-Ni SMA ribbons.


Assuntos
Ligas/química , Alumínio/química , Materiais Biocompatíveis/química , Cobre/química , Ligas Dentárias/química , Níquel/química , Animais , Apoptose , Sobrevivência Celular , Corrosão , Masculino , Camundongos , Oxigênio/química , Ratos , Baço/citologia , Propriedades de Superfície , Sais de Tetrazólio/química , Tiazóis/química , Timo/citologia
16.
Srp Arh Celok Lek ; 136(3-4): 95-103, 2008.
Artigo em Sérvio | MEDLINE | ID: mdl-18720740

RESUMO

INTRODUCTION: Root coverage supported with complete regeneration of lost periodontal tissues represents the ultimate goal of gingival recession treatment. OBJECTIVE: This study was designed to evaluate clinical effectiveness of platelet rich plasma gel (PRP) with connective tissue graft (CTG) in the treatment of gingival recession. METHOD: 15 gingival recessions Miller class I or II were treated with CTG and PRP (group PRP). Connective tissue graft was harvested from the premolar region using trap door technique. After elevation of the flap, the regional bone and root surface were smeared with activated PRP gel. CTG was also irrigated with PRP gel before placement over the exposed root surface and local bone. Fixed CTG was covered with a coronally advanced flap. The same number of gingival recessions were treated with CTG in combination with the coronally advanced flap with no PRP gel (group TVT). Clinical recordings included recession depth (RD), probing depth (PD), clinical attachment level (CAL) and keratinized tissue width (KT) before and 1 year after mucogingival surgical treatment. RESULTS: Mean value of RD was significantly decreased from 4.93 +/- 0.86 mm to 0.60 +/- 0.37 (p < 0.01) with CTG and PRP and from 4.76 +/- 0.74 mm to 0.63 +/- 0.29 mm (p < 0.01) in CTG group. This difference was not statistically significant. Results of the keratinized tissue width showed significant increase from 0.88 +/- 0.30 mm presurgery to 3.78 +/- 0.49 mm (p < 0.01) six months after treatment in PRP group and from 0.90 +/- 0.34 mm to 3.15 +/- 0.41 in TVT group (p < 0.01). This difference was statistically significant (p > 0.05). No statistically significant differences were observed between treatment groups in CAL and PD. CONCLUSION: Clinical results validate both procedures as effective and highly predictable surgical techniques in solving gingival recession problem. Histological evaluation may confirm advantage of PRP use related to regeneration of periodontal tissues.


Assuntos
Retração Gengival/cirurgia , Plasma Rico em Plaquetas , Adulto , Tecido Conjuntivo/transplante , Retração Gengival/patologia , Humanos
17.
Srp Arh Celok Lek ; 134(1-2): 22-9, 2006.
Artigo em Sérvio | MEDLINE | ID: mdl-16850573

RESUMO

INTRODUCTION: Sleep bruxism as nocturnal parafunction, also known as tooth grinding, is the most common parasomnia (sleep disorder). Most tooth grinding occurs during rapid eye movement - REM sleep. Sleep bruxism is an oral habit characterized by rhythmic activity of the masticatory muscles (m. masseter) that causes forced contact between dental surfaces during sleep. Sleep bruxism has been associated with craniomandibular disorders including temporomandibular joint discomfort, pulpalgia, premature loss of teeth due to excessive attrition and mobility, headache, muscle ache, sleep interruption of an individual and problems with removable and fixed denture. Basically, two groups of etiological factors can be distinguished, viz., peripheral (occlusal) factors and central (pathophysiological and psychological) factors. The role of occlusion (occlusal discrepancies) as the causative factor is not enough mentioned in relation to bruxism. OBJECTIVE: The main objective of this paper was to evaluate the connection between occlusal factors and nocturnal parafunctional activities (occlusal disharmonies and bruxism). METHOD: Two groups were formed- experimental of 15 persons with signs and symptoms of nocturnal parafunctional activity of mandible (mean age 26.6 years) and control of 42 persons with no signs and symptoms of bruxism (mean age 26.3 yrs.). The computerized occlusal analyses were performed using the T-Scan II system (Tekscan, Boston, USA). 2D occlusograms were analyzed showing the occlusal force, the center of the occlusal force with the trajectory and the number of antagonistic tooth contacts. RESULTS: Statistically significant difference of force distribution was found between the left and the right side of the arch (L%-R%) (t=2.773; p<0.02) in the group with bruxism. The difference of the centre of occlusal force - COF trajectory between the experimental and control group was not significant, but the trajectory of COF was longer in the group of bruxists (67.3+24.4mm). In addition, the significant difference of COF position in relation to the center of the elliptic fields was not found in bruxists (chi-squared=1.63; p> 0.05), but obtained results directly revealed uneven distribution of the occlusal forces which caused the excessive attrition and mobility of tooth. CONCLUSION: Our study failed to find direct correlation between occlusal factors and bruxism, so they are basically contributing factors.


Assuntos
Oclusão Dentária , Processamento de Imagem Assistida por Computador , Bruxismo do Sono/patologia , Adulto , Força de Mordida , Feminino , Humanos , Masculino , Bruxismo do Sono/fisiopatologia
18.
J Craniofac Surg ; 17(3): 572-8, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16770202

RESUMO

The etiology of craniomandibular disorders (CMD) is multi-factorial and the treatment should be selected with recognition of the different factors. The aim of the study was to investigate the influence of occlusion splint therapy (Michigan splint), physical exercises and transcutaneous nerve stimulation (TENS) on CMD symptomatology. At the Clinic of Maxillofacial Surgery in Belgrade, in the period from May, 2001-December, 2003, 168 patients were examined by the CMD working group. This group, comprised of different specialties (maxillofacial surgeon, prosthodontist, orthodontist, neurologist, psychiatrist and physiatrician), enabled multidisciplinary treatment of CMD patients according to the guidelines given by American Academy for Craniomandibular Dysfunctions. In all, a total of 30 patients with prevalent muscular tensions among other CMD symptoms were included in this study. The examination form according to Fricton and Shiffman for Craniomandibular Index (CMI) was used in order to evaluate the function of Craniomandibular system before and after therapy.A statistically significant difference (t = 8,735; P < 0,001) between the average values for CMI of patients before (0,2297 +/- 0,0827) and after therapy (0,1002 +/- 0,0479) was observed. Performed treatment resulted in complete response (pain relief and absence of CMD symptoms and signs) in over than 80% of patients and could be considered as a method of choice in reversible occlusal therapy.


Assuntos
Transtornos Craniomandibulares/terapia , Placas Oclusais , Adulto , Transtornos Craniomandibulares/classificação , Oclusão Dentária Central , Desenho de Equipamento , Terapia por Exercício , Dor Facial/classificação , Dor Facial/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular , Planejamento de Assistência ao Paciente , Equipe de Assistência ao Paciente , Estimulação Elétrica Nervosa Transcutânea , Resultado do Tratamento
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