Effect of different solutions on knoop hardness of indirect composite

Introduction: Indirect dental composites may have adequate clinical performance. However, the literature is scarce regarding indirect composite resins and these solutions should be considered to maintain their properties. The aim of the study was to evaluate the influence of beverages, mouthwashes and bleaching agents on the hardness of indirect composite resins. Methods: Five different brands of indirect composite resins were evaluated: Adoro, Resilab, Cristobal, Sinfony and Epricord. Ten specimens of each brand were immersed in eleven different solutions: four mouthwashes (Listerine, Oral-B, Plax, Periogard), four beverages (coke soft drink, red wine, coffee, orange juice), three dental bleaching agents (16% peroxide of carbamide, 7.5% and 38% peroxide of hydrogen) and artificial saliva (control group). The Knoop hardness was measured before (baseline) and after 12, 24, 36 and 60 hours of immersion in mouthwashes; after 7, 14 and 21 days of immersion in beverages and after 7 and 14 days of immersion in dental bleaching agents. The results were analyzed using 3-way repeated measures ANOVA and Tukey’s test (p<0.05). Results: All resins presented significant decrease on hardness values after immersion process whereas this reduction was higher for Resilab and Sinfony. The latter exhibited the lowest initial values of hardness while Cristobol resin presented the highest hardness values. The mouthwashes promoted a significant decrease in the hardness of specimens.

Reabilitação estética por meio de prótese ocular a base de PMMA: relato de caso

Eye loss results on facial asymmetry compromising its aesthetics. Ocular prostheses are important to re-establish aesthetics; protect the anophthalmic cavity; recover function such as the redirection of lachrymatory liquid; and reintegrate the patient to society. The aim of this study was to describe a case report, demonstrating clinical and laboratorial procedures for confection of ocular prostheses and highlighting their advantages. A female patient was afflicted by toxoplasmosis, which led to the loss of her eye. An eye visceration was performed. The patient reported no previous use of ocular prosthesis. A PMMA ocular prosthesis was manufactured restoring patient’s aesthetic and facial contour. The patient was satisfied with the treatment. Therefore the present study has shown that PMMA ocular prosthesis is able to restore facial aesthetics and can be a safe and satisfactory alternative for patients that have lost their eyes due to toxoplasmosis.

Effect of weathering and thickness on the opacity of acrylic resin and ocular button for artificial eyes

The aim of this study was to evaluate the opacity of the polymethylmethacrylate for ocular prosthesis using an ocular button, a colorless resin for the ocular prostheses, and 4 brands of acrylic colorless resin in the function of weathering (0, 504, or 1008 h) and thickness (1 and 3.5 mm). One hundred twenty specimens were confectioned (made) and allocated into 12 groups (n = 10). Opacity analysis was carried out with a spectrophotometer of visible ultraviolet reflection before and after weathering by 504 and 1008 hours. Data for the opacity were expressed in ΔE. Data were then analyzed statistically by analysis of variance and the Tukey test (P < 0.01). The data demonstrated statistically significant differences; manufactured ocular button (ΔE = 47.4) and the resin Vipi Cril (ΔE = 38.11) presented greater and minor values of opacity, respectively. The weathering showed statistical difference among times (0 h, ΔE = 36.32; 504 h, ΔE = 39.98; and 1008 h, ΔE = 43.9). Ocular button and evaluated resins presented greater values of opacity when presented in 3.5 mm in thickness. The values of opacity increased with the progression of the time of weathering, independent of the evaluated material and the thickness.

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.

Composite resin susceptibility to red wine staining after water sorption

Color stability of restorative materials is essential for longevity of esthetic composite restoration over time. The aim of this investigation was assess the effect of prior water immersion on the color stability of a composite resin to red wine staining. Seventy disccshaped specimens (6mm x 1.5mm) were carried out and randomized in 7 groups (n = 10), according to distilled water immersion time at 0 (control), 24, 48, 72,120,192, and 240 h. Baseline color was measured according to the ciel*a*b* system using a reflection spectrophotometer(uvc2450, shimadzu).After that, the specimens were storage in red wine for 7 days. Color difference (∆e) after aging was calculated based on the color coordinates before(baseline) and after storage period.Data were subjected to onecway anova(alpha=0.05).The different times of immersion in.Water before to the red wine storage showed similar behavior on the color stability, without statistical difference compared to control group, immersed directly in the wine(p=0.7057).The previous water uptake of composite resin evaluated did not decrease the susceptibility to red wine staining.

Dental care for cerebral palsy patients using auxiliary resources to inhibit pathological tonic reflexes

Cerebral paralysis is a chronic illness that affects the central nervous system. In this article the author describes the techniques used at CAOE (Odontological Center for Assistance to patients with special needs) to restraint CP patients during dental treatment, because they present some pathological reflexes which interfere in their odontological assistance. Also it shows how to perform a special physical restraint and how to keep the mouth open by using simple tools including a homemade one. All the devices used during the dental treatment in cerebral palsy patients, such as the physical restraint with bands or sheet to wrap them up, cylindrical pad or cushion made of a soft material, or simple tools including a homemade one to keep the mouth open are usually and safely used in CAOE. All these simple devices are necessary, because there are no available funds for the acquisition of expensive material or equipment. Despite of a shortage of resources we can easily and efficiently assist these patients.

Avaliação da resistência adesiva de diferentes sistemas resinosos de colagem ortodôntica

Recent orthodontic bonding materials have aimed to reduce the working time of the clinician, by simplifying the acid etching procedure by applying self-etching primer adhesive systems. However, the adhesion quality of these materials still demands investigation. Thus, the present study aimed to evaluate the bond strengths of three different adhesive systems. A hundred and eighty bovine lower incisors were cut and embebbed in acrylic resin matrices, in which orthodontic brackets were bonded with Transbond XT (2n = 60), Transbond XT Self Etching Primer (2n = 60) e Tyrian (2n = 60). For each composite, bond strength tests were executed immediately (n = 30) and 24 hours (n = 30) after the bonding, in the assay machine Versat 2000 (Pantec), by applying 500 Kgf of load at 1mm/min of velocity. Transbond XT, Transbond XT Self Etching Primer and Tyrian presented, respectively, average values of bond strength of 7.43, 7.09 and 3.41 MPa at the time immediately, and 7.42, 8.81 and 5.35 MPa at 24 hours after the bonding, where differences were statistically significant at 5% between Tyrian and Transbond groups at both observation times. It was concluded that Tyrian was the material that presented significant lower bond strength with regard to Transbond groups that were similar.

Emprego de ma teriais rest auradores adesivos direto no ângulo incisal de incisivos centrais fra turados

A case report of a patient who presents as chief complaint presence of stained restorations in the anterior teeth. After analysis and discussion of the clinical therapeutic approaches to be adopted, it was observed the presence of type class IV restorations on teeth 11 and 21, due to an oblique coronal fracture in the past. But the patient was not satisfied with the aesthetic result, then where was planned the realization of the removal of the restorations, for subsequently be used direct restorative materials for the correction of form, function and esthetics. The final result showed that the restorations were able to return the form, function and aesthetic dental, thereby evidencing the proven development of restorative dentistry in the solution of aesthetic problems.

Avaliação da termociclagem sobre a estabilidade de cor de diferentes matizes de resina composta

The objective was to evaluate the effect of thermocycling on the color variation of three different composite resins . We studied was Resin Enamel on 3 levels : ( Esthetic X , Opallis and Venus ) ; Resin Dentin in three levels : ( Esthetic X , Opallis and Venus ) and Thermocycling on level 1 : ( 3,000 cycles ) ; variable was the change of color gauged by spectrophotometry . 60 specimens , subdivided into 6 groups were made : GI - Esthetic X Enamel ; GII - Esthetic X dentin ; GIII - Opallis Enamel ; GIV - Opallis dentin ; GV - Enamel and GVI Venus - Venus dentin . The specimens were prepared with a matrix to standardize samples . The inserts of incrementally resins and polymerized with a halogen light Ultralux unit ( Dabi Atlante , Brazil ) with a power of 450mW / cm ² . After fabrication , underwent color reading with a UV Visible Spectrophotometer reflection , UV -2450 ( Shimadzu , Kyoto , Japan ) , with the changes calculated by the system CIE L * a * b * . Then isolates were stored in artificial saliva at 35 ° C ± 2 ° C during 3 months containers being subjected to the effects of thermal cycling for 3000 cycles over the range of 5C to 55C . Again subjected to chromatic evaluation. For the analysis of the results of color change of the studied resins was applied ANOVA two factors at 5 % . The results showed a statistically equal resins enamel GI and GV ( p = 0.79 ) ; the same was not observed for GI and G III resins , where the color change was higher for resin G III ( p = 0.0000002 ) . The same was observed between G III and GV , where the resin enamel G III showed a statistically superior to the color change ( p = 0.0000005 ) Average . Resins to dentin was there a statistical equality between the materials studied . We conclude that the resins studied change in color and resin enamel G III was the most suffered major color changes after aging by thermocycling .

Diastemas: reestablishment of an attractive smile

A healthy and attractive smile is very valued in today s society. Yet this requires better aesthetic and cosmetic solutions from dental surgeons.The present paper presents a case report of diastema closure using an association of tooth movement induced by orthodontic elastics,dental cosmetics and resin-bonded prosthesis. The female patient L.B.A.J., aged 19 years, visited the Integrated Clinic of Araçatuba DentalSchool UNESP mainly complaining of missing teeth and poor esthetics. After anamnesis, clinical and radiographic examination revealedhypodontia of the maxillary right and left first premolars, abnormal maxillary right lateral incisor shape and diastema between the maxillaryright lateral incisor and canine and between the maxillary left lateral incisor and canine. Planning was done which included indication ofdiastema closure with composite resin restoration and metal-free resin-bonded prosthesis, with a structure made of Vectris (Ivoclar VivadentInc., Amherst, NT, USA). The option for dental cosmetics associated with resin-bonded prosthesis after movement with orthodontic elasticsresulted in an excellent aesthetic outcome of low cost and short treatment duration.Indexing terms: composite resins; diastema; fixed resin bonded partial denture.

Effect of different light sources on degree of conversion, hardness and plasticization of a composite

Clinical performance of composite resins depends largely on their mechanical properties,and those are influenced by several factors,such as the light-curing mode. The purpose of this study was to evaluate the influence of different light sources on degree of conversion(DC), Knoop hardness(KHN) and plasticization(P) of a composite resin. Disc-shaped specimens (5 x 2 mm) of Esthet-X(Dentsply) methacrylate-based microhybrid composite were light-cured using quartz-tungsten-halogen (QTH) Optilight Plus(Gnatus) or light-emitting diode(LED) Ultraled(Dabi Atlante) curing units at 400 and 340 mW/cm2 of irradiance, respectively. After 24 h, absorption spectra of composite were obtained using Nexus 670(Nicolet)FT-IR spectrometer in order to calculate the DC.The KHN was measured in the HMV-2000(Shimadzu) microhardness tester under 50 g loads for 15 s, and P was evaluated by percentage reductio of hardness after 24 h of alcohol storage. Data were subjected to t-Student test(alpha=0.05).QTH device showed lower P and higher KHN$ than LED (p<0.05), and no difference between the light-curing units was found for DC (p>0.05). The halogen-curing unit with higher irradiance promoted higher KHN and lower softening in alcohol than LED.

In vitro reduction of Streptococcus mutans biofilm on silver nanoparticle-modified resin composite

Introduction: Currently, new methods to reduce biofilm formation on biomaterials are very studied, for example the use of silver nanoparticles, which were bactericidal. However, there are few studies investigating the benefits of these particles in dental restorative materials. Objective: This study aimed to compare in vitro the Streptococcus mutans biofilm formation on conventional light-cured composite resin with that on experimental light-cured composite resin, modified with silver nanoparticles. Material and methods: Discs were produced with either conventional resin (control group) and resin modified with different concentrations of silver nanoparticles, 0.1%, 0.3% and 0.6 % wt. (groups 1, 2 and 3, respectively). The samples were incubated in bacterial suspension (S. mutans) enriched with 20% sucrose to promote biofilm growth on the surfaces. Incubation times were 1, 4 and 7 days. After each period, adherent biofilms were disaggregated by ultrasound. Then, the numbers of viable cells recovered from the biofilms were counted through the serial dilution method. A morphological analysis of biofilm was also performed by Scanning Electron Microscopy. The data were subjected to Anova and Tukey’s test (α = 0.05). Results: The number of viable cells was statistically lower in groups 2 and 3 than in group 1 and control group, after the three incubation periods, without statistical difference between groups 2 and 3. The number of viable cells was statistically lower in group 1 than in control group, after 4 and 7 days of incubation. Conclusion: Resins modified with silver presented reduction of S. mutans biofilm on their surfaces, according to the conditions of this study.

Análise do efeito de inseticidas neonicotinóides sobre a orientação e coleta de alimento de operárias de Apis mellifera L., 1758 (Hymenoptera: Apidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Emprego de carvão ativado e resinas de troca ionica na remoção de substâncias orgânicas contaminantes do alcool etílico

This work had with objective to characterize and evaluate the performance of the combined system, involving activated charcoal and ionic exchange resins in the removal of substances organic contaminating of the ethyl alcohol from the fermentation of the cassava starch. To testing was used ethyl alcohol PA 96 oGL, conductivity of 0.90 μS/cm at 25 oC, acidity of 60 mg/L and Barbet test of 43 minutes at 15 oC. The contaminated alcohol was composed of ethyl alcohol additive of higher alcohols, organic acids, ester, diol, aldehydes, ketone and ether. Contaminated alcohol was added 2% activated charcoal and after the adsorption isotherm in ionic exchange resins was tested. The adsorption with activated charcoal was performed in a Water Bath at 30 oC for one hour and a half and shaking. Already adsorption ionic exchange columns occurred at room temperature on columns of 93,4 cm in filling height and diameter of 2.29 cm, for flows of 180 mL/min and 90 mL/min. Samples were collected in the tests with charcoal and with each one of the resins and the following analyses were performed: conductivity, acidity and Barbet test. The medium values for conductivity, acidity and Barbet test after the adsorption in charcoal and cation and anion resins were respectively: conductivity was 240; 354 and 465 μS/cm to 25 oC; acidity of 1.081; 1.103 and 1.062 mg/L and the Barbet test was 21; 20 and 9 minutes to 15 oC. It was observed that the addition of 2% of activated charcoal and the permanence in the columns of adsorption was not sufficient to remove the organic substances contaminating of the ethyl alcohol.

Avaliação farmacognóstica qualitativa das folhas do vegetal Bambusa textilis

Introduction: Bamboos belong to the family Graminae, Bambusoidae subfamily, represented by about 1,250 species worldwide. Originally employed in construction and power, are currently the subject of investigations related to its therapeutic properties in neoplasms. The main species used for therapeutic purposes based on popular knowledge are: Phyllostachys nigra; Bambusa breiflora; tuldoides Bambusa textilis and Bambusa. The literature on the therapeutic action of bamboo species is scarce, but recent studies report a promising effect in the treatment of cancer and other chronic diseases. Objective: This study aimed to evaluate qualitatively the phytochemical composition of plant extract obtained from the leaves of the bamboo species Bambusa textilis, comparing this composition from vegetable leaves with 18 and 24 months of age. Methodology: After collecting plant leaves with 18 or 24 months, they were identified and submitted to drying and milling. For qualitative analysis of its components were employed methods of macroscopic evaluation (mucilage), method of benzoin (resin), reaction Shinoda (flavonoids), reaction with gelatin solution (tannins), boiling and foaming (saponins) and jobs of reactive Wagner, Bertrand, Dragendorff, Mayer, picric acid and tannic acid (alkaloids) (Biavatti; MILK, 2007). Results: in the youngest leaves were found positive for alkaloids, flavonoids, resins and saponins. In the leaves of the plant with 24 months were found only alkaloids flavonoids and resins. Conclusion: the composition of vegetable substances were found associated with a significant therapeutic potential difference and the phytochemical composition in comparison with plant leaves 18 or 24 months. Additional studies are needed to quantify these components, as well as the clarification of its action in the fight against cancer and chronic diseases.