How the translucency of direct anatomic fiber posts affects the bond strength and microhardness of a self-adhesive luting agent in flared roots.

OBJECTIVES: To evaluate the influence of the composite resin translucency used in direct anatomic fiber posts on the bond strength (BS) and microhardness (VHN) of a luting agent into flared roots. MATERIALS AND METHODS: The root canals of 70 single-rooted premolars were endodontically treated and prepared to simulate an oversized root canal. Prior to post cementation, composite resins with varying translucency (high translucent, HT; medium translucent, MT; high opacity, HO) were placed around the fiber posts to create anatomic fiber posts. The attenuation profile (%) of light passing either through the post or through the anatomic posts (n = 8) was obtained prior to the cementing procedures. A positive control group (PC) in which a prefabricated fiber post (PFP) with the diameter compatible with the root canal was cemented and a poorly adapted fiber post (negative control group, NC) were also evaluated. For both tests, the data were subjected to 2-way ANOVA and Bonferroni tests (α = 0.05). RESULTS: A more severe light attenuation through the post at the cervical (P < .001) and medium (P < 0.001) thirds was noted when less translucent composite resin surrounded the anatomic post. HO groups showed lower BS (P = .009) and VHN (P < .001) values than the other groups, regardless of root third. No significant difference in BS values was noted between PC and HT groups. CONCLUSION: The use of a more translucent composite resin in anatomic fiber posts increased the microhardness and bond strength of a dual polymerization self-adhesive RLA compared to the use of MT and HO composite. A well-adapted PFP showed the highest adhesive and mechanical behavior. CLINICAL RELEVANCE: Clinicians should choose more translucent composite resins to create direct anatomic fiber posts to be cemented in flared root canals. That choice may allow improved mechanical properties of self-adhesive RLA and higher bond strength to the root canal as a consequence.

Alternative esthetic management of fluorosis and hypoplasia stains: blending effect obtained with resin infiltration techniques.

STATEMENT OF PROBLEM: New light-polymerized resin composites optimized for rapid infiltration of enamel lesions with resin light curing monomers are commercially available today to prevent enamel lesions from further demineralization and provide a highly conservative therapy. In addition, this technique has proved to be effective treatment for blending white spot lesions because the microporosities of infiltrated lesions are filled with resin. PURPOSE: This clinical report presents and describes cases in which the minimally invasive infiltrant resin technique was used for blending different microporous lesions, mild-to-moderate fluorosis, and hypoplasia stains related to traumatic dental injuries. RESULTS: The fluorosis stain showed visually perceptual improvements. In the cases of hypoplasia, stains were not completely blended. However, the general clinical outcomes of these cases were considered successful and recovered the patients' self-esteem. CONCLUSION: Based on the results obtained, it could be concluded that the resin infiltration technique shows promising results and could be considered a minimally invasive procedure for mild-to-moderate fluorosis and hypoplasia stains. CLINICAL SIGNIFICANCE: This case study allows a better understanding of the concept of the resin infiltration technique applied in other types of porous lesions, increasing its use as a therapeutic alternative for esthetic purposes in the philosophy of minimally invasive dentistry.

Clinical effectiveness of two microabrasion materials for the removal of enamel fluorosis stains.

This study evaluated the effectiveness of two microabrasion products for the removal of enamel fluorosis stains. Using a split-mouth study design, two operators used PREMA (PM) and Opalustre (OP) to remove fluorosis-like stains from 36 subjects (10-12 years old). Both products were rubbed onto the surface of the affected teeth for 30 seconds. This procedure was repeated five times during each clinical appointment. A maximum of three clinical appointments were scheduled. The subjects and/or their parents were questioned about their satisfaction with the treatment. Two blinded evaluators appraised both sides of the mouth using a visual scale system. The data were analyzed by Friedman repeated measures ANOVA and Wilcoxon test. The majority of the subjects (approximately 97%) reported satisfaction at the end of the treatment (p = 0.0001). A significant improvement in appearance was detected after the second clinical appointment when using PREMA and Opalustre (p < 0.002). After the first clinical appointment, OP showed a statistically higher mean rating for improvement in appearance (3.4 +/- 0.7) than PM (2.4 +/- 0.5) (p = 0.002).

Efeito de diferentes sistemas de fotopolimerização na microdureza de uma resina composta Bleach Shade / Efecto de diferentes sistemas de fotopolimerización en la microdureza de una resina compuesta Bleach Shade / Effect of different light-curing units of photoactivation on the microhardness of composite resin Bleach Shade

O objetivo deste estudo foi comparar o efeito de três aparelhos fotopolimerizadores sobre a microdureza Vickers da resina composta Filtek Z250/3M-ESPE cor B0.5. Os aparelhos testados foram: GI - Curing Light 2500/3M-ESPE (775mW/cm²), GII - LED:ELIPAR FreeLight 2/3M-ESPE (609mW/cm²) e GIII - Ultra Lume LED2/Ultradent (818mW/cm²). Para a confecção dos corpos-de-prova (CP), foram utilizadas matrizes metálicas contendo uma cavidade interna com 2 mm de espessura e 5 mm de diâmetro. Cinco CP foram confeccionados para cada grupo avaliado. O material foi fotopolimerizado por 40 segundos. O microdurômetro MMT-3 (Buehler) foi utilizado com carga de 50 gf durante 30 segundos, realizando-se quatro impressões nas superfícies de topo e base de cada CP. O teste ANOVA e o teste t foram aplicados para analisar os dados. GI e GIII mostraram diferenças estatisticamente significantes, quando comparado o valor obtido na superfície de topo com o valor da superfície de base (p<0,05). Quando comparados os valores de microdureza da superfície de topo entre aparelhos, houve diferença estatisticamente significante de GI com GII e GIII e para superfície de base entre GI e GII, comparados com GIII (p<0,05). Concluiu-se que o aparelho de luz halógena proporcionou maiores valores de microdureza na superfície de topo, quando comparado com os aparelhos à base de LEDs. Para a superfície de base, o aparelho UltraLume LED 2/Ultradent proporcionou os menores resultados