RESUMEN
AIM: The aim of this in vitro study was to evaluate the diametral compressive bond strength between Charisma or TPH composite resin after association or not to an adhesive system in incremental filling technique. METHODS: Twenty cylinders of each composite resin brand were fabricated using a Teflon matrix and divided into four groups, according to the numbers of adhesive layers applied: group 1 Control without adhesive; group 2 one layer; group 3 two layers and group 4 three layers. The bonding system Adper Single Bond was used between composite resin increments. Diametral compression assays were carried out in an EMIC-MEM 2000 universal testing machine, adjusted at 1 mm/min. ANOVA and Tukey's test were used in the statistical analysis. RESULTS: The mean strengths and standard deviations for each group were: Charisma 1= 38.26+/-2.38; 2=46.56+/-2.38; 3=40.57+/-2.38; 4=36.87+/-2.38 (2>1=3=4; P<0.05) and TPH 1=52.17+/-2.38; 2=52.23+/-2.38; 3=44.68+/-2.38; 4=44.11+/-2.38 (1=2>3=4; P<0.05). CONCLUSIONS. It was concluded that TPH presented higher means of compressive bond strength than Charisma, and the association of an adhesive system between the increments may influence the diametral compressive bond strength of composite resins.
Asunto(s)
Resinas Compuestas , Fuerza Compresiva , Recubrimiento Dental Adhesivo , Cementos Dentales , Restauración Dental Permanente/métodos , Humanos , Ensayo de MaterialesRESUMEN
AIM: Amalcomp is a technique that combines composite resin to amalgam in restorative procedures to improve esthetics and minimize the negative effects of polymerization on dental tissues. The objective of this in vitro study was to measure the diametral compressive bond strength between Fill Magic composite (Vigodent) versus Permite (DFL) or Velvalloy (SS White) amalgams in different oxidation stages. METHODS: Twenty-four cylinders of each amalgam brand were fabricated using a Teflon matrix and divided into 3 groups according to the immersion period in artificial saliva for oxidation: A (1 day), B (7 days) and C (30 days). After immersion, the amalgam cylinders were bonded to the composite specimens using the Scotch Bond Multi Use Plus (3M) bonding system. Diametral compression assays were then carried out in an EMIC-MEM 2000 universal testing machine set to 0.5 mm/min. Statistical analysis was performed using ANOVA and Tukey's test. RESULTS: The mean recorded strength (MPa) for each oxidation group was: A=9.71, B=8.21 and C=6.98 (A>B = C; P<0.01). Permite (7.24) provided significantly less adhesion to the composite than Velvalloy (9.36; P<0.05). There was no interaction between the factors alloy, resin and time. CONCLUSIONS: Under the conditions of this study, the less oxidized amalgam showed the greatest diametral compressive strength values.
Asunto(s)
Resinas Compuestas/química , Aleaciones Dentales/química , Amalgama Dental/química , Recubrimiento Dental Adhesivo , Fuerza Compresiva , Cobre/química , Ensayo de Materiales , Oxidación-Reducción , Saliva Artificial/química , Plata/química , Factores de TiempoRESUMEN
The aim of this study was to evaluate in vivo the use of low-level galium-aluminium-arsenide (GaAlAs) (BDP 600) laser and sodium fluoride varnish (Duraphat) in the treatment of cervical dentine hypersensitivity. Twelve patients, with at least two sensitive teeth were selected. A total of 60 teeth were included in the trial. Prior to desensitizing treatment, dentine hypersensitivity was assessed by a thermal stimulus and patients' response to the examination was considered to be a control. The GaAlAs laser (15 mW, 4 J/cm2) was irradiated on contact mode and fluoride varnish was applied at cervical region. The efficiency of the treatments was assessed at three examination periods: immediately after first application, 15 and 30 days after the first application. The degree of sensitivity was determined following predefined criteria. Data were submitted to analysis and no statistically significant difference was observed between fluoride varnish and laser. Considering the treatments separately, there was no significant difference for the fluoride varnish at the three examination periods, and for laser therapy, significant difference (P < 0.05) was found solely between the values obtained before the treatment and 30 days after the first application. It may be concluded that both treatments may be effective in decreasing cervical dentinal hypersensitivity. Moreover, the low-level GaAlAs laser showed improved results for treating teeth with higher degree of sensitivity.