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1.
SADJ ; 68(3): 122-9, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23951776

RESUMEN

BACKGROUND: Several tooth whiteners are available on the market, and the ideal choice should be determined by efficacy and optimal clinical results. OBJECTIVES: The purpose of this study was to compare the reported clinical success rates of different tooth whitening products. SEARCH STRATEGY: The relevant literature (1998 - 2011) was studied, using as sources the databases: Google Scholar, Science Direct, Medline and Pubmed. SELECTION CRITERIA: The material was clearly identified, the manufacturers' instructions were respected and the sample size stated. RESULTS AND CONCLUSIONS: This descriptive report on 49 papers focuses on the total colour change, measured with a calibrated shade guide and also numerically (colourimeter, chromameter or spectrophotometer), the relapse of the colour change and tooth sensitivity. In general, the dentist-supervised at-home bleaching and the in-office treatment gave approximately the same initial percentage improvement of tooth whitening. However, the relapse after a four week or longer period was significantly higher for the in-office treatment. The treatment of choice should be a dentist supervised at-home bleaching product which generally contains approximately 10% carbamide peroxide applied over about 14 days for about eight hours per night. Tooth sensitivity should not be a general problem although some subjects might choose to discontinue treatment as a result of sensitivity.


Asunto(s)
Toma de Decisiones , Blanqueadores Dentales/uso terapéutico , Color , Colorimetría , Humanos , Recurrencia , Espectrofotometría , Diente/patología , Decoloración de Dientes/tratamiento farmacológico , Decoloración de Dientes/patología , Resultado del Tratamiento
2.
Int J Dent ; 2011: 167525, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21747855

RESUMEN

The purpose of this study was to evaluate the efficacy of two different 10% carbamide peroxide bleaching products just after treatment and after a 6-month follow-up period. Methods. Two 10% carbamide peroxide products (Opalescence PF and Nite White ACP) were applied nightly for 14 days, according to the manufacturers' instructions. The color of teeth 11 and 21 of thirty-four subjects having A2 or darker teeth were measured with a spectrophotometer (L(∗); a(∗); b(∗)) before treatment, just after treatment (14 days) and after 6 months. Results and Conclusions. Both products produced significant whitening of teeth with total color change (ΔE(ab) (∗)) of approximately 5.20 units. There was a significant improvement in all 3 color coordinates (L*, a*, and b(∗)) for up to 6 months postbleaching (P < .05). Nite White showed a higher degree of relapse (27%) than Opalescence (18%) over the 6-month period. It is suggested that rebleaching after 6 months is not necessary.

3.
J Dent ; 38(2): 113-7, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19781594

RESUMEN

OBJECTIVES: To evaluate the effectiveness of Opalescence PF 10% just after treatment, at 6-month follow-up and at a 14-month follow-up period. METHODS: Opalescence PF 10% was applied nightly for 14 days. The color of teeth 11 and 21 of 17 subjects were measured with a spectrophotometer (L*; a*; b*) before treatment, just after treatment (14 days), after 6 months and after 14 months. Subjects were instructed to take note of any tooth sensitivity. RESULTS: For all three components (L*, a* and b*) statistical significant differences (p<0.05) in the values between base-line, after treatment (14 days later), after 6 months and after 14 months were found (Wilcoxon Signed Rank Sum Test). The decrease in L* was about 20% after 6 months and about 50% after 14 months. The a* value decreased approximately 14% after 6 months but was worse after 14 months than at the beginning. The b* value decreased the least with about 9% after 6 months and about 8% after 14 months. The decrease in DeltaE(ab)(*) was approximately 20% after 14 months. Less than 20% of the subjects experienced mild tooth sensitivity just after treatment. CONCLUSION: Significantly whiter teeth were found after treatment as well as after a 6-month follow-up period. The whiteness/brightness (L*) decreased with approximately 50% after 14 months and the a* value with approximately 50% after 7 months, while the yellowness (b* value) remained even after 14 months. CLINICAL IMPLICATIONS: The product is an effective tooth whitener resulting in only low tooth sensitivity. Re-bleaching could be done at about 14 months.


Asunto(s)
Oxidantes/uso terapéutico , Peróxidos/uso terapéutico , Polivinilos/uso terapéutico , Espectrofotometría , Blanqueamiento de Dientes/métodos , Diente/patología , Urea/análogos & derivados , Color , Sensibilidad de la Dentina/clasificación , Combinación de Medicamentos , Estética Dental , Estudios de Seguimiento , Humanos , Ensayo de Materiales , Retratamiento , Autocuidado , Diente/efectos de los fármacos , Resultado del Tratamiento , Urea/uso terapéutico , Adulto Joven
4.
Open Dent J ; 3: 48-54, 2009 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-19444344

RESUMEN

This field study included the whole population of children aged 10-15 years (77 from a 0.19 mg/L F area; 89 from a 3.00 mg/L F area), with similar nutritional, dietary habits and similar ethnic and socioeconomic status. The fluoride concentration in the drinking water, the bone mineral content, the bone density and the degree of dental fluorosis were determined. The left radius was measured for bone width, bone mineral content, and bone mineral density. The mean fluorosis score was 1.3 in the low fluoride area and 3,6 in the high fluoride area. More than half the children in the low fluoride area had no fluorosis (scores 0 and 1) while only 5% in the high fluoride area had none. Severe fluorosis (30%) was only observed in the high fluoride area. The Wilcoxon Rank Sum Test indicated that fluorosis levels differed significantly (p < 0.05) between the two areas. No relationships were found between dental fluorosis and bone width or between fluorosis and bone mineral density in the two areas (Spearment Rank correlations). A significant increase in bone width was found with age but no differences amongst and boys and girls. A significant positive correlation was found in the high fluoride area between bone mineral density over age. In the 12-13 and 13-14 year age groups in the high fluoride area, girls had higher bone mineral densities. However, a significant negative correlation (p<0.02) was found for the low fluoride area (0.19 mg/L F) over age.

5.
J Forensic Odontostomatol ; 27(2): 29-44, 2009 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-22785094

RESUMEN

The standard age estimation methods of Moorrees, Fanning & Hunt (1963) and that of Demirjian, Goldstein & Tanner (1973) have been shown by several authors to be inaccurate when applied to their juvenile population. This was similarly found to be true in South African children. Pantomographic radiographs of samples of South African children of White, Coloured, Indian and Black origin were used to develop dental age related tables for these ethnic groups. These dental age estimation tables were tested and are presented.


Asunto(s)
Determinación de la Edad por los Dientes/métodos , Etnicidad , Adolescente , Diente Premolar/crecimiento & desarrollo , Población Negra/etnología , Niño , Preescolar , Diente Canino/crecimiento & desarrollo , Etnicidad/etnología , Humanos , Incisivo/crecimiento & desarrollo , India/etnología , Diente Molar/crecimiento & desarrollo , Radiografía Panorámica , Sudáfrica/etnología , Ápice del Diente/crecimiento & desarrollo , Corona del Diente/crecimiento & desarrollo , Raíz del Diente/crecimiento & desarrollo , Población Blanca/etnología
6.
J Forensic Odontostomatol ; 27(2): 20-8, 2009 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-22785095

RESUMEN

Dental age estimation of juvenile skeletal remains has utilized the methods of Moorrees ,Fanning and Hunt (1963) [MFH] and Demirjian,Goldstein and Tanner (1973) [DGT] for many years with various results. The Demirjian et al method has been tested by several authors on their population groups with varying results.The use of these methods to age the skeletal remains of South African children by the author has not been successful. The aim of this study was to test the accuracy of the dental age estimation methods of MFH and DGT on samples of children of different ethnic groups.The study showed that the MFH method consistently under-estimates the age and the method of Demirjian et al over-estimates theages.


Asunto(s)
Determinación de la Edad por los Dientes/métodos , Etnicidad , Adolescente , Factores de Edad , Población Negra/etnología , Niño , Preescolar , Femenino , Humanos , India/etnología , Masculino , Radiografía Panorámica , Sudáfrica/etnología , Población Blanca/etnología
7.
SADJ ; 63(5): 282-4, 286, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18811078

RESUMEN

OBJECTIVES: The purpose was to evaluate the effect of various Opalescence tooth-whitening products on enamel. METHODS AND MATERIALS: Enamel blocks were exposed to Opalescence PF 10% Carbamide Peroxide (n = 10), Opalescence PF 20% Carbamide Peroxide (n = 10), Opalescence Trèswhite Supreme 10% Hydrogen Peroxide (n = 10) and Opalescence Quick PF 45% Carbamide Peroxide (n = 10) according to the manufacturer's instructions. The control group was enamel blocks (n = 10) kept in artificial saliva. The values were obtained before exposure and after the 14-days treatment period. Enamel blocks were kept in saliva between treatments. Indent marks on enamel blocks were examined using the scanning electron microscope for treatment effects. RESULTS: All four different Opalescence products damaged enamel. The most damage was done when treated for a long period (112 hours). SEM images also showed damage to enamel by all 4 products. Opalescence with 10% and with 20% Carbamide Peroxide showed the highest damage, which also differed significantly (p < 0.05) from the saliva control group (p < 0.05; Tukey-Kramer Multiple comparison test). CONCLUSION: All 4 Opalescence products damaged enamel. Higher damage was done by the 10% carbamide peroxide and 20% carbamide peroxide products because of the much longer exposure period (112 hours in comparison to 7 hours).


Asunto(s)
Esmalte Dental/efectos de los fármacos , Peróxido de Hidrógeno/farmacología , Oxidantes/farmacología , Peróxidos/farmacología , Blanqueamiento de Dientes/métodos , Urea/análogos & derivados , Peróxido de Carbamida , Esmalte Dental/patología , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Dureza , Humanos , Peróxido de Hidrógeno/administración & dosificación , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Oxidantes/administración & dosificación , Peróxidos/administración & dosificación , Saliva Artificial/química , Factores de Tiempo , Urea/administración & dosificación , Urea/farmacología
8.
Health SA Gesondheid (Print) ; 9(4): 55-65, 2004.
Artículo en Inglés | AIM (África) | ID: biblio-1262574

RESUMEN

Migraine affects between 5.15of males and 13;5-31of females in South Africa. Little is known about the prescribing patterns of anti-migraine drugs in South Africa. The aim of the study was to investigate the prescribing of drugs for the treatment of migraine (ATC Group NOZC); with specific emphasis on sumatriptan; in a primary care patient population in South Africa; making use of a computerised prescription database. A total of 3 01 1 products for the treatment of migraine at a cost of R451559 were prescribed to 578 patients in the study over a period of one year (1996) since sumatriptan was the onlytriptan available in South Africa in 1996. The average age of patients was 48;40 (SD = 14;19) years; with 74;57ofpatients between 20 and 59 years of age. Approximately 80of patients were females. Female patients were prescribed 81;53of the products. Most drugs (67;55) were for the prophylaxis of migraine; of which clonidine andflunarizine were the most frequentlyprescribed. Of the drugs prescribedspecifically for the management of migraine; sumatriptan (575prescriptions to 103 patients) was the most frequently prescribed; followed by 400 prescriptions for ergotamine. Tablets were the preferred dosage form. Since migraine affects primarily the economically active sector of the community and its treatment is relatively expensive; pharmacists have an important role to play in managing and counselling migraine sufferers


Asunto(s)
Utilización de Medicamentos , Trastornos Migrañosos/terapia , Farmacoepidemiología , Sumatriptán
9.
SADJ ; 58(9): 360-2, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14964049

RESUMEN

The aim of this study was to investigate the erosive effect of different wine samples on the enamel of human permanent teeth. Twenty-one extracted, sound, permanent human incisor teeth were imbedded in epoxy resin and seven immersed in each of the three different wine samples for 0, 2, 5, 15, 30, 45 and 60 minute periods. The Knoop hardness for each tooth at each of the immersed periods was determined as a measure of the degree of enamel erosion (demineralisation). The main finding was that all three wines eroded enamel (softer enamel) which should mainly be due to their very low pH values (3.2, 3.7, 3.8) and high total acid content. From the Wilcoxon non-parametric tests it was clear that wine 2 had the severest influence on the hardness of the teeth, and the wines differed significantly (p < 1%) from 30 minutes onwards. These tests showed that wine 1 differed significantly from wine 2 from 30 minutes onwards and so did wine 3, but wines 1 and 3 did not differ at all (p > 5%). It is concluded that all three wine samples were erosive to enamel and it is difficult to predict the relative erosion rate of different kinds of wines according to their chemical compositions, as this process is most probably governed and affected by a large number of a combination of factors. The only reliable way to know the exact degree of erosion of a specific wine is by means of a laboratory study. Possible ways to decrease the damaging effect of erosion caused by wine are provided.


Asunto(s)
Erosión de los Dientes/etiología , Vino/efectos adversos , Análisis de Varianza , Solubilidad del Esmalte Dental , Dureza , Humanos , Concentración de Iones de Hidrógeno , Incisivo
10.
Gen Dent ; 50(4): 352-6, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12640852

RESUMEN

The purpose of this study was to study the relationship between degree of fluorosis and varying fluoride concentrations in the drinking water in a relatively dry region in South Africa. A strong positive association was found between drinking water fluoride levels and fluorosis but only up to a level of approximately 2.0 ppm for areas with a high average daily temperature (approximately 79 degrees F). The results indicate that the optimum drinking water fluoride concentration for a region with a high average daily temperature should be less than 1.00 ppm.


Asunto(s)
Cariostáticos/análisis , Fluoruros/análisis , Fluorosis Dental/clasificación , Abastecimiento de Agua/análisis , Adolescente , Factores de Edad , Distribución de Chi-Cuadrado , Niño , Clima , Dieta , Femenino , Humanos , Masculino , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Población Rural , Clase Social , Sudáfrica , Estadísticas no Paramétricas , Temperatura
11.
Int J Paediatr Dent ; 11(5): 372-9, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11572269

RESUMEN

OBJECTIVES: The purpose of this study was to determine the relationship between caries experience, degree of fluorosis and different concentrations of fluoride in the drinking water of children. SAMPLE AND METHODS: The study included 282 children aged 10-15 years, who lived continuously since birth in three different naturally fluoridated areas (Leeu Gamka, 3.0; Kuboe 0.48 and Sanddrif 0.19 p.p.m. F), with virtually no dental care or any fluoride therapy The teeth of the children were examined for caries using the DMFT index according to th WHO criteria and for fluorosis, using Dean's criteria according to the WHO guidelines. RESULTS: The prevalence of fluorosis (scores 2, 3, 4 and 5) among the school children was 47% in Sanddrif, 50% in Kuboes and 95% in Leeu Gamka. Almost half the children in the two low fluoride areas had no fluorosis (scores 0 and 1), whereas only 5% in Leeu Gamka had no fluorosis. Of the children in Sanddrif, 42.5% had very mild/mild (scores 2 and 3) fluorosis, 44.3% in Kuboes and 34.1% in Leeu Gamka. Except for one individual in Kuboes, severe fluorosis (score 5) was only observed in the high fluoride area in 30% of the children. According to the Bonferroni adaptation for multiple comparisons, the degree of fluorosis in Leeu Gamka differed significantly from both those of Sanddrif and Kuboes. The mean DMFT for the children in Sanddrif and Kuboe was similar (164 +/- 0.30 and 1.54 +/- 0.24, respectively) but the caries experience of Leeu Gamka (198 +/- 0.22) was significantly higher (P < 0.05) than that of both the other two areas. A strong positive correlation (P < 0.05) was found between the caries experience and the fluorosis scores of children in the high fluoride area (Leeu Gamka) but no correlation could be found in the other two areas. Significantly (P < 0.01) more children had decayed teeth in the high F area (Leeu Gamka) than in the other two areas. CONCLUSION: The results suggest a positive association between high F levels in the drinking water and dental caries. Furthermore, a low caries experience and no difference in DMFT and fluorosis between the two low fluoride areas were found.


Asunto(s)
Cariostáticos/análisis , Caries Dental/clasificación , Fluoruros/análisis , Fluorosis Dental/clasificación , Abastecimiento de Agua/análisis , Adolescente , Cariostáticos/efectos adversos , Distribución de Chi-Cuadrado , Niño , Índice CPO , Femenino , Fluoruros/efectos adversos , Humanos , Masculino , Variaciones Dependientes del Observador , Prevalencia , Reproducibilidad de los Resultados , Sudáfrica , Estadística como Asunto , Estadísticas no Paramétricas
12.
SADJ ; 56(2): 64-70, 2001 Feb.
Artículo en Africano | MEDLINE | ID: mdl-16894691

RESUMEN

This-study was undertaken to evaluate and compare microleakage in class V cavities in human teeth which were lined with Amalgambond Plus with HPA (Parkell, USA), Optibond Solo (Kerr, U.S.A.), Fuji Plus (GC Corporation, Japan) and Prime & Bond 2.1 (Dentsply, Switzerland), and then restored with Logic amalgam (SDI Australia). The restored teeth were thermocycled in basic fuchsin dye, sectioned, and evaluated for dye penetration. The interdiffusion zones were viewed in a confocal laser scanning microscope (CLSM). The results showed that no bonding system could totally eliminate microleakage. Statistical analysis revealed significant differences between Amalgambond Plus with HPA and Prime & Bond 2.1, Fuji Plus as well as Optibond Solo, for both the enamel and dentine sides. No significant differences were found between Prime & Bond 2.1, Fuji Plus and Optibond Solo, for both the enamel and dentine sides. Amalgambond Plus showed significantly more leakage at dentine sides while Prime & Bond 2.1 showed significantly more leakage at enamel sides. The CLSM revealed hybrid layers of different thicknesses, resin penetration into tubules, as well as resin incorporation within the spherical particles of the amalgam. Optibond Solo, Fuji Plus and Prime & Bond 2.1 can serve to improve the marginal seal of amalgam restorations.


Asunto(s)
Recubrimiento Dental Adhesivo , Recubrimiento de la Cavidad Dental/métodos , Preparación de la Cavidad Dental/métodos , Filtración Dental/prevención & control , Adaptación Marginal Dental , Acetona/uso terapéutico , Amalgama Dental/uso terapéutico , Caries Dental/terapia , Materiales Dentales/uso terapéutico , Restauración Dental Permanente/métodos , Recubrimientos Dentinarios/uso terapéutico , Humanos , Metacrilatos/uso terapéutico , Ácidos Polimetacrílicos/uso terapéutico
13.
Arch Oral Biol ; 45(7): 607-9, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10785525

RESUMEN

The purpose of this study was: (1) to measure the lead concentrations in various parts of the teeth (enamel, dentine and circumpulpal dentine) and in blood from individuals of a remote rural South African community; (2) to investigate any correlation between the lead concentrations in these various dental tissues and in blood; and (3) to estimate blood lead from the tooth lead concentrations reported in other studies. Primary teeth and blood were collected from 48 children and analysed by graphite-furnace atomic absorptiometry. The following median concentrations (expressed in mg/kg) of lead were found: blood, 0.025; enamel, 0.25; dentine, 2.04; circumpulpal dentine, 6.71. The tooth lead concentrations were similar to those from other studies from remote rural areas but comparisons of blood lead were not possible in the absence of previous data. Blood lead in other studies could be calculated from the ratios here reported.


Asunto(s)
Esmalte Dental/química , Dentina/química , Plomo/análisis , Niño , Femenino , Humanos , Masculino , Población Rural , Sudáfrica , Espectrofotometría Atómica/estadística & datos numéricos , Diente Primario/química
14.
J Ren Nutr ; 10(1): 7-15, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10671628

RESUMEN

This prospective nonintervention single-center study was undertaken to investigate the role of protein-energy malnutrition (PEM) as a risk factor for morbidity in patients on long-term hemodialysis. Thirty-seven patients from the renal unit of Tygerberg Hospital, Tygerberg, South Africa, were studied for a mean period of 26 months. Morbidity was the main outcome and was defined as the number of hospitalizations and days of hospitalization per patient per year. Investigations included 4-monthly determinations of interdialytic protein catabolic rate (PCR), dietary intake of protein and energy, blood levels of albumin and urea, lymphocyte count, adequacy of dialysis (Kt/V), body weight, intradialytic weight loss, fat mass (FM), fat-free mass (FFM), body mass index (BMI), and bone-free arm muscle area (BF-AMA). A PEM composite score was derived from postdialysis serum albumin, BF-AMA, FM, FFM, and BMI. All-cause morbidity as defined by number of hospitalizations (see text for other definitions of morbidity) showed a significant correlation with the mean and baseline PEM score (P <.01), and a negative correlation with predialysis and postdialysis serum albumin (P <.05) and age (P <.05). There was no significant relationship with PCR, percentage intradialytic weight loss, Kt/V, reuse of dialyzer, period on maintenance hemodialysis, sex, race, and type of dialyzer membrane. When "only infection-related" morbidity was considered, the factors that showed a significant correlation were the mean (P <. 001) and baseline PEM score (P <.01), and percentage intradialytic weight loss (P <.01). There was no significant deterioration in the nutritional status of patients followed up for at least 24 months. It is concluded that infection-related morbidity was associated most strongly with the PEM score and the percentage intradialytic weight loss. The results suggest that PEM is one of the important contributing factors to morbidity, possibly via an effect on the immune system and infection.


Asunto(s)
Enfermedades Renales/complicaciones , Enfermedades Renales/terapia , Desnutrición Proteico-Calórica/complicaciones , Diálisis Renal , Adulto , Anciano , Índice de Masa Corporal , Proteínas en la Dieta/administración & dosificación , Femenino , Hospitalización , Humanos , Enfermedades Renales/mortalidad , Masculino , Persona de Mediana Edad , Morbilidad , Estado Nutricional , Estudios Prospectivos , Proteínas/metabolismo , Factores de Riesgo , Albúmina Sérica/análisis , Pérdida de Peso
15.
Quintessence Int ; 31(7): 501-8, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11203971

RESUMEN

OBJECTIVE: This study was undertaken to determine the relative shear bond strengths and microleakage of 4 bonding agents to dentin and amalgam and to investigate the bonding to dentin through confocal laser scanning microscopy. METHOD AND MATERIALS: Sixty noncarious molars were restored with 1 of 4 different systems, and the shear bond strengths were determined. For the microleakage study, Class V amalgam restorations were placed in 60 noncarious teeth. The specimens were thermocycled, the teeth were sectioned, and dye penetration was assessed. For confocal examinations, the first component of the bonding adhesives was labeled with rhodamine B. Each of the adhesives was applied to 3 dentin specimens, which were examined under a confocal laser scanning microscope RESULTS: Of the 4 restorative systems tested, AmalgamBond Plus + HPA and Prime & Bond 2.1/base-catalyst showed significantly higher shear bond strengths. Prime & Bond 2.1/base-catalyst had the lowest microleakage value, which was significantly lower than that of AmalgamBond Plus + HPA and AmalgamBond Plus. AmalgamBond Plus + HPA had the highest variation in both the bond strength and microleakage values. Confocal laser scanning microscopy revealed tag formation, penetration of the bonding agents deep into the tubules, and hybrid layer formation for all 4 bonding systems. CONCLUSION: The 2 best systems, Prime & Bond 2.1/base-catalyst and, to a lesser extent, AmalgamBond Plus + HPA, utilized a supplemental bonding agent.


Asunto(s)
Aleaciones Dentales/química , Amalgama Dental/química , Recubrimiento Dental Adhesivo , Filtración Dental/clasificación , Recubrimientos Dentinarios/química , Acrilatos/química , Bisfenol A Glicidil Metacrilato/química , Restauración Dental Permanente/clasificación , Dentina/ultraestructura , Colorantes Fluorescentes , Humanos , Ensayo de Materiales , Metacrilatos/química , Microscopía Confocal , Diente Molar , Ácidos Polimetacrílicos/química , Rodaminas , Estrés Mecánico , Propiedades de Superficie , Termodinámica
16.
J Forensic Odontostomatol ; 17(1): 1-4, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10709555

RESUMEN

The composite resin, compomer and glass ionomer restorative materials used in modern dental practice are fire resistant and remain radiopaque. They shrink significantly and are likely to fall out of the cavities after being burnt, but they remain extremely important for identification purposes and it may be possible to identify the white filling materials used to restore teeth by their radiopacity and morphology. The radiographic density of these filling materials do not change significantly when exposed to heat and although they may be difficult to see with the naked eye, they will remain visible when radiographed. Furthermore, special care has to be taken when handling heated materials as their compressive strengths decrease significantly depending on temperature and time of exposure and damage is possible.


Asunto(s)
Compómeros/química , Resinas Compuestas/química , Restauración Dental Permanente , Odontología Forense , Cementos de Ionómero Vítreo/química , Análisis de Varianza , Fuerza Compresiva , Medios de Contraste , Calor , Humanos , Ensayo de Materiales , Metacrilatos , Radiografía Dental , Resinas Sintéticas , Silicatos , Dióxido de Silicio , Circonio
17.
Int Dent J ; 49(1): 47-52, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10887473

RESUMEN

The purpose of this study was to determine the relative microleakage of five restorative systems when bonded to dentine/cementum. For the microleakage determination Class V cavity preparations were prepared on the facial surfaces of 65 teeth (10-15 for each material) below the cemento-enamel junction and restored. The root apices were sealed, the teeth coated with nail varnish except for 1 mm surrounding the restorations and the specimens were thermocycled (x500) in 2 per cent methylene blue solution. Root sections including the restorations were dissolved in acid and the concentrations of the dye determined spectrophotometrically. The sequence of the microleakage values were: Dyract < OptiBond < AeliteBond < All-Bond 2 < ScotchBond. It is concluded that Dyract had the lowest microleakage at dentine/cementum interface, which may increase the longevity of the restorative in the clinical situation, with no, or less secondary caries.


Asunto(s)
Resinas Compuestas/química , Filtración Dental/prevención & control , Restauración Dental Permanente , Recubrimientos Dentinarios/química , Grabado Ácido Dental , Diente Canino , Cemento Dental/efectos de los fármacos , Filtración Dental/etiología , Restauración Dental Permanente/clasificación , Restauración Dental Permanente/métodos , Dentina/efectos de los fármacos , Técnica de Dilución de Colorante , Humanos , Técnicas In Vitro , Ensayo de Materiales/métodos , Ensayo de Materiales/estadística & datos numéricos , Azul de Metileno , Estadísticas no Paramétricas
18.
J Dent ; 26(3): 259-65, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9594479

RESUMEN

OBJECTIVE: The aim of this study was to determine, in vitro, the relative short- and long-term fluoride release from four resin-modified glass ionomers (Fuji II LC, Vitremer, Enforce & Advance), a polyacid-modified composite resin (Dyract compomer) and a bonding agent (OptiBond). METHODS: All the materials were prepared as outlined by the manufacturers. Circular discs of the materials mentioned were suspended in water for up to 300 days and the non-cumulative 24-h fluoride release was determined potentiometrically at chosen times. RESULTS: The amounts of fluoride released during the first day were Vitremer (1.46 micrograms mm-2), Advance (1.18 micrograms mm-2), Fuji (1.08 micrograms mm-2), Optibond (0.33 microgram mm-2), Dyract (0.31 microgram mm-2) and Enforce (0.15 microgram mm-2). After the second day the sequence changed slightly and remained approximately the same for the rest of the 300-day period. There was also an increase in the fluoride release during the 60-200-day period relative to the previous period. CONCLUSION: In general the most fluoride was released by Advance and not by Fuji II LC or Vitremer. For most materials, fluoride is still released after 300 days. Furthermore, even a thin layer of bonding agent released a relatively high amount of fluoride (volume-wise the most) at the beginning. It is deduced that even the release of relatively low amounts of fluoride may result in significant concentrations of fluoride in a microleakage gap.


Asunto(s)
Cariostáticos/química , Compómeros , Resinas Compuestas/química , Fluoruros/química , Cementos de Ionómero Vítreo/química , Cementos de Resina/química , Análisis de Varianza , Recubrimientos Dentinarios/química , Ensayo de Materiales , Metacrilatos/química , Resinas Sintéticas/química , Silicatos/química , Estadísticas no Paramétricas
19.
Health Phys ; 74(4): 419-28, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9525414

RESUMEN

The genetically significant dose was initially defined by UNSCEAR in 1958. The National Radiological Protection Board (NRPB) derived a formula from this definition as shown in the NRPB Report, NRPB-R106. It combines the frequency of radiological examinations obtained during the country-wide survey and estimates of gonadal doses for different examination types, together with population and child expectancy data. The task was set to find a model in order to draw the best representative sample of the population, and it was determined in a unique way, namely the so-called Dollar Unit Sampling method. A sample of 27 institutions out of a possible 292 (9%) was drawn. The GSD for the total South African population was calculated, using the above-mentioned formula, as 95 microGy. The breakdown of the genetically significant dose for the various South African race groups was Asian--229 microGy; black--67 microGy; people of color (mixed race)--112 microGy; and white--463 microGy.


Asunto(s)
Genitales/efectos de la radiación , Dosis de Radiación , Traumatismos por Radiación/epidemiología , Radiografía/estadística & datos numéricos , Factores de Edad , Recolección de Datos , Relación Dosis-Respuesta en la Radiación , Femenino , Humanos , Masculino , Grupos Raciales , Factores Sexuales , Sudáfrica
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