ABSTRACT
OBJECTIVE: To evaluate the effect of 3% phosphate ascorbyl gel (PA) in different times onto the microshear bond strength of composite resin (CR) to bovine enamel treated with 35% hydrogen peroxide (HP). MATERIALS AND METHODS: Thirty enamel blocks of bovine incisors were made and divided into 5 groups (n = 6) with three specimens per group (n = 18), according to treatment: G1= No bleaching + CR; G2 = HP + CR after 15d; G3 = HP + CR after 24 hours; G4 = HP + PA (15 min) + CR after 24 hours; G5 = HP + PA (2 hours) + CR after 24 hours. The resin cylinders were made by Tygon matrices. Microshear bond strength test was performed using universal testing machine with a 50N load at a speed of 0.5 mm/min. Fracture modes were assessed by a stereomicroscope 40 ×. Microshear bond strength values were submitted to the analysis of variance (ANOVA) one-way and Tukey test (p < 0.05). RESULTS: G1 had significant results when compared to G3 and G5 (p < 0.01). However, G2, G3, G4 and G5 have showed no significant differences among groups (p > 0.05). Failure modes were categorized into adhesive (90%) and mixed (10%). CONCLUSION: The use of 3% phosphate ascorbyl gel for 15 minutes was able to improve bond strength of composite resin to bleached bovine enamel, but when 3% phosphate ascorbyl gel was applied during 40 minutes it negatively interfered in the adhesion of the resin to bleached bovine enamel.
Subject(s)
Antioxidants/chemistry , Ascorbic Acid/analogs & derivatives , Composite Resins/chemistry , Dental Bonding , Dental Enamel/ultrastructure , Dental Materials/chemistry , Hydrogen Peroxide/pharmacology , Tooth Bleaching Agents/pharmacology , Animals , Ascorbic Acid/chemistry , Cattle , Dental Bonding/methods , Dental Enamel/drug effects , Dental Stress Analysis/instrumentation , Hydrogen Peroxide/chemistry , Light-Curing of Dental Adhesives/methods , Materials Testing , Resin Cements/chemistry , Shear Strength , Stress, Mechanical , Surface Properties , Temperature , Time Factors , Tooth Bleaching Agents/chemistry , Water/chemistryABSTRACT
The rehabilitation of patients requiring an esthetic smile demands a multidisciplinary approach. This clinical report describes a treatment plan for recovery aesthetics' smile of anterior teeth using ceramic prosthesis with zirconia structure. Initially, a review of aesthetic parameters, diagnostic waxing, mock-up and provisional restorations was performed. A contextual assessment of aesthetic, proportion and shape of teeth was done to recreate a natural looking for teeth in consonance with the smile line. Subsequently, based on these parameters, fixed prostheses of the upper anterior teeth using ceramic restorations with zirconia infrastructures were performed. The use of ceramic restorations with zirconia structures associated with a careful treatment plan allows the professional to integrate esthetic and function for satisfactory clinical results. How to cite the article: Tavarez RR, Gonçalves LM, Dias AP, Dias AC, Malheiros AS, Silva AC, Bandeca MC. An harmonic smile resulted from the use of ceramic prosthesis with zirconia structure: A case report. J Int Oral Health 2014;6(3):90-2.
ABSTRACT
Introdução: o desenvolvimento de materiais e técnicas na Odontologia Restauradora tem como finalidade a obtenção de um confiável vedamento marginal, pois a microinfiltração ainda é um dos principais motivos de insucesso das restaurações. Objetivo: analisar "in vitro" o efeito da configuração cavitária e do tipo de sistema adesivo na microinfiltração em restaurações classe V, em esmalte, com resina composta. Material e método: foram selecionados 60 dentes bovinos, confeccionadas 30 cavidades na face vestibular de forma retangular e 30 de forma circular, sendo então divididos aleatoriamente em seis grupos, conforme a forma geométrica e o sistema adesivo utilizado: Magic Bond, Adper Single Bond 2 e Clearfil SE BOND. Os dentes foram restaurados com resina composta Z-350, utilizando um incremento, fotopolimerizado por 40 segundos, e feito o acabamento/polimento com disco Sof-Lex. Posteriormente, os dentes foram armazenados em água destilada à temperatura ambiente por sete dias e impermeabilizados com esmalte cosmético, deixando uma margem de 1 mm ao redor da restauração. Foram imersos, então, em solução aquosa de nitrato de prata a 50% por um período de duas horas no escuro, lavados com água corrente, colocados em solução reveladora por seis horas, lavados, seccionados no centro da restauração e as fatias foram analisadas na lupa estereoscópica de 25× de aumento. Os dados foram submetidos à análise estatística não paramétrica de Kruskal-Wallis (p < 0,05). Resultado: não houve diferença estatisticamente significante para ambos os fatores analisados (p = 0,233 e p = 0,158). Conclusão: a forma da cavidade não influenciou na microinfiltração; todos os adesivos comportaram-se de maneiras semelhantes quanto à microinfiltração.
Introduction: the development of materials and techniques in restorative dentistry aims to achieve a good marginal sealing because microleakage is still one of the main reasons for failure of restorations. Objective: To analyze "in vitro" the effect of cavity configuration and the type of adhesive system on microleakage of class V resin composite, in enamel. Material and method: 60 bovine teeth were selected, and 60 cavities were prepared on the buccal surface, 30 rectangular and 30 rounded shaped. They were randomly divided in 6 groups according to the geometric form and the bonding system used: Magic Bond, Adper Single Bond 2 and Clearfil SE BOND. The teeth were restored with Z-350 composite resin, using one increment, lightcured for 40 seconds and polished with a Sof-Lex disc. After that the teeth were stored in distilled water at room temperature for seven days and further sealed with nail varnish, leaving a 1 mm window around the restoration margin. They were then immersed in 50% aqueous silver nitrate solution for 2 hours in the dark, rinsed under tap water, placed in revealing solution for 6 hours under fluorescent light, washed, sectioned in the center of the restoration and the slices were viewed under stereoscopic glasses at 25× magnification. The data were submitted to Kruskal-Wallis non-parametric test (p < 0.05). Result: no statistically significant difference for either factor analyzed (p = 0.233 and p = 0.158) was observed. Conclusion: the cavity shape did not influence in microleakage; all the adhesives behaved in similar manners as to microleakage.
