ABSTRACT
Objective @#To explore the effects of two hemostatic agents on the bonding strength of different bonding systems in primary tooth dentin.@*Methods @# Seventy-two retained deciduous teeth were randomly selected. Forty-eight teeth were used to construct the microleakage model, the other 24 teeth were cut along the mesial and distal directions and 48 samples were obtained to construct the shear bond strength model. The two experiments were divided into 2 groups. Group A was the total-etch group: A1 (ViscoStat + Spectrum Bond NT); A2 (ViscoStat Clear + Spectrum Bond NT); and A3 (Non + Spectrum Bond NT); Group B was the self-etch group: B1 (ViscoStat + Single bond Universal Adhesive); B2 (ViscoStat Clear + Single bond Universal Adhesive); and B3 (Non + Single bond Universal Adhesive). Microleakage experiments and shear bond strength experiments were carried out respectively and the morphology of the fracture surface was observed by scanning electron microscopy.@* Results @#There was no significant difference in microleakage among groups A1, A2, and A3 (P > 0.05). There was no significant difference in microleakage among groups B1, B2, and B3 (P > 0.05). There was no significant difference in the shear bond strength among groups A1, A2 and A3 (P > 0.05). The shear bond strength of groups B1 and B2 was significantly lower than that of group B3 (P < 0.05). There was no significant difference between groups B1 and B2 (P > 0.05). @*Conclusion@#ViscoStat and ViscoStat Clear had no effect on the marginal integrity of deciduous tooth dentin under the different bonding systems. The two hemostatic agents reduced the shear bonding strength of deciduous tooth dentin under the self-etch adhesive system, but had no effect on the shear bonding strength of deciduous tooth dentin under the total-etch adhesive system.
ABSTRACT
El presente estudio evaluó el grado de sellado marginal y resistencia adhesiva de restauraciones de resinas compuestas confeccionadas con un sistema adhesivo de grabado y lavado en dentición primaria y definitiva. Para realizar ambos test se utilizaron 20 piezas primarias y 20 piezas definitivas. En resistencia al cizallamiento, los dientes fueron seccionados longitudinalmente y se les adhirió un cilindro de resina compuesta, utilizando la técnica adhesiva de grabado y lavado para ambas denticiones. Posteriormente, fueron testeados en una máquina de ensayos universales Tinius Olsen, aplicando una fuerza de cizallamiento de 200 kg y a una velocidad de cabezal de 0,2 cm/min. Para el test de sellado marginal, se les realizó una preparación cavitaria clase V, por vestibular/palatino estandarizada. Luego se les confeccionaron restauraciones de resina compuesta con la técnica de grabado y lavado, y se sometieron al termociclado con azul de metileno al 2%; después fueron cortados y observados al microscopio óptico estereoscópico con aumento de lupa, para medir el porcentaje de microfiltración obtenido. El valor promedio de la resistencia adhesiva al cizallamiento para dentición primaria fue de 8,49 Mpa, y de 9,52 Mpa para dentición definitiva, no encontrándose diferencias estadísticamente significativas entre los grupos en estudio. En la investigación sobre el grado de sellado marginal se evaluó el porcentaje de microfiltración y tampoco se encontraron diferencias estadísticamente significativas, lo que señalaría que ambos tejidos son igualmente susceptibles de ser tratados adhesivamente mediante la técnica de hibridación.
The present study evaluated the degree of marginal seal and adhesive resistance of composite resin restorations prepared with an etch and rinse adhesive system in primary and definitive dentition. To perform both tests, 20 primary pieces and 20 permanent pieces were used. In the shear strength resistance, the teeth were sectioned longitudinally and were adhered to composite resin cylinder, using the etch and rinse technique for both dentitions. They were then tested on a Tinius Olsen universal testing machine, applying a shear force of 200 kg and a head speed of 0.2 cm/min. For the margin seal test, a class V cavity preparation of standardised vestibular/palatine was made. The composite resin restorations were made with the etch and rinse technique and were subjected to thermocycling with 2% methylene blue. Later, they were cut and observed using a stereoscopic optical microscope with loop magnification to measure the percentage of microfiltration obtained. The mean value of the adhesive resistance to shearing for primary dentition was 8.49 Mpa, and 9.52 Mpa for permanent teeth, with no statistically significant differences being found between the groups studied. In the test on the degree of margin seal the percentage microfiltration was measured, with no statistically significant differences being found either. The results showed that both tissues are equally susceptible to being treated adhesively using the hybrid technique.
Subject(s)
Humans , Tooth, Deciduous , Adhesives , Composite Resins , Shear Strength , Dental Leakage , Dental Stress Analysis , Materials ScienceABSTRACT
OBJECTIVES: This study evaluated the influence of chlorhexidine (CHX) on the microtensile bonds strength (microTBS) of resin core with two adhesive systems to dentin in endodontic cavities. MATERIALS AND METHODS: Flat dentinal surfaces in 40 molar endodontic cavities were treated with self-etch adhesive system, Contax (DMG) and total-etch adhesive system, Adper Single Bond 2 (3M ESPE) after the following surface treatments: (1) Priming only (Contax), (2) CHX for 15 sec + rinsing + priming (Contax), (3) Etching with priming (Adper Single Bond 2), (4) Etching + CHX for 15 sec + rinsing + priming (Adper Single Bond 2). Resin composite build-ups were made with LuxaCore (DMG) using a bulk method and polymerized for 40 sec. For each condition, half of specimens were submitted to microTBS after 24 hr storage and half of them were submitted to thermocycling of 10,000 cycles between 5degrees C and 55degrees C before testing. The data were analyzed using ANOVA and independent t-test at a significance level of 95%. RESULTS: CHX pre-treatment did not affect the bond strength of specimens tested at the immediate testing period, regardless of dentin surface treatments. However, after 10,000 thermocycling, all groups showed reduced bond strength. The amount of reduction was greater in groups without CHX treatments than groups with CHX treatment. These characteristics were the same in both self-etch adhesive system and total-etch adhesive system. CONCLUSIONS: 2% CHX application for 15 sec proved to alleviate the decrease of bond strength of dentin bonding systems. No significant difference was shown in microTBS between total-etching system and self-etching system.