RESUMEN
This study investigated the effectiveness of polymerization of various curing regimes on five nanocomposite restorative materialsZ350, Grandio, Clearfil Majesty Esthetic, Ice and Tetric EvoCeramby utilizingmicrohardnessmeasurements. Five (n=5) disc-shaped specimens of each material were subjected to one of three curing regimes: curing with a halogen light for 20 seconds, curing with an LED light for 20 seconds and curing with an LED light for 10 seconds. Immediately following curing, hardness measurements were made with a Vickers indenter at five different locations on both the top and bottom surfaces of each disc. The mean for each surface was calculated. Data were analyzed using a one-way ANOVA and post-hoc Tukey HSD (α=0.05). The results demonstrated that among the Z350 composite samples, top and bottom microhardness values showed no statistical differences when cured with the halogen 20 second or LED 20 second regimes (p>0.05). Comparison of the top and bottom values of discs cured with the LED 10 second regime demonstrated significant differences (p<0.0001). Grandio samples cured with the halogen 20 second regime showed no statistical differences between top and bottom microhardness values (p>0.05); however, the bottom values of Grandio discs cured with the LED 20 second and 10 second regimes were significantly lowerwhen comparedwith top surface values (p=0.001 and p<0.0001, respectively). Clearfil Majesty Esthetic, Ice and Tetric EvoCeram samples cured with the halogen 20 second regime produced significantly lower bottom microhardness values, while both LED regimes produced top and bottom surfaces that were statistically comparable. The conclusion may be drawn that LED 10 second curing regimes were insufficient to cure Z350 and Grandio, while they were adequate for curing Clearfil Majesty Esthetic, Ice and Tetric EvoCeram.
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Humanos , Trinidad y Tobago , Odontología , Región del Caribe , Nanocompuestos , Polimerizacion , DurezaRESUMEN
Purpose: The purpose of this study was to assess the shear bond strength of amalgam when bonded to dentine with various cements. Materials and Methods: Eighty human molars were divided into five groups and ground dentine surfaces treated, with one of five cements (Fuji I, Vitrebond, Rely X, Fuji II and Panavia F). Spherical amalgam (Tytin) was condensed onto the unset cement and shear bond strengths were measured after one week. Results: The mean shear bond strength of Panavia F (25.3 MPa) was significantly higher compared with Fuji I (16.8 MPa), Fuji II (10.3 MPa) and Vitrebond (5.1 MPa) however there was no significant difference with Rely X (19.0 MPa). Conclusion: The combination of a resin modified glass ionomer luting cement with a spherical alloy may enhance bonding of amalgam to dentine.
Asunto(s)
Humanos , Técnicas In Vitro , Amalgama Dental/análisis , Cementos de Ionómero Vítreo/análisis , Cementos de Ionómero Vítreo , Resistencia al CorteRESUMEN
Many of the new materials and techniques used in endodontics (root canal treatment) require considerable practice to master and many require continuing education courses to allow formal instruction. Nothing is known regarding techniques employed and views on continuing professional education (CPE) in endodotics by dentists in Trinidad and Tobago. With the shift toward evidence-based dentistry and rising patient expectation of quality oral health care, a survey was conducted to describe these issues. A self-administered postal questionnaire was sent to all registered dentists in Trinidad and Tobago. Seventy dentists responded after two mailings. Most respondents worked primarily in private practice (85.5 percent). Years since qualification ranged from 2 to 45 years and 54.3 percent were qualified for more than 10 years. Most frequent treatment of an acute dental abcess involved opening, preparing the canal(s), dressing and prescribing antibiotics (40 percent). Forty-one respondents (58.6 percent) ocassionally completed root canal treatment in a single visit. Isolation of the tooth for molar root treatment always caused difficulty for thirty-five respondents (50 percent) and rubber dam isolation was used routinely by only nine respondents (12.9 percent). Most respondents either filed (20 percent) or reamed (18 .6 percent) for canal preparation usually using K files. Thirty-three respondents (47 percent) used sodium hypochlorite to irrigate the tooth and thirty-one (44.3 percent) used cold lateral condensation of gutta percha to obturate. Thirty-four respondents (48.6 percent) subscribed to professional journals and sixty-seven (95.7 percent) had attended some form of Continuing Professional Education. Sixty-seven (95.7 percent) of respondents would attend CPE in endodontics if available in Trinidad and Tobago, with most (72.9 percent) preferring a lecture/seminar format addressing problem-solving and new techniques. Respondents to this survey showed use of a wide range of techniques and materials but still expressed considerable interest in developing their skills in endodontics through formal CPE. (AU)