The incorporation of nanostructured hydroxyapatite increases the adhesive properties and may be a promising filler for adhesive resin.

Niobium pentoxide could be used to produce adhesive resins with enhanced properties.

Orthodontic treatment with fixed brackets plays a major role on the formation of white spot lesions. Objective This study aimed to incorporate silver nanoparticle solutions (AgNP) in an orthodontic adhesive and evaluate its physicochemical and antimicrobial properties.Material and Methods Silver nanoparticle solutions were added to a commercial adhesive in different concentrations (w/w): 0%, 0.11%, 0.18%, and 0.33%. Shear bond strength (SBS) test was performed after bonding metal brackets to enamel. Raman spectroscopy was used to analyze in situ the degree of conversion (DC) of the adhesive layer. The surface free energy (SFE) was evaluated after the measurement of contact angles. Growth inhibition of Streptococcus mutans in liquid and solid media was determined by colony-forming unit count and inhibition halo, respectively. One-way ANOVA was performed for SBS, DC, SFE, and growth inhibition.Results The incorporation of AgNP solution decreased the SBS (p<0.001) and DC in situ (p<0.001) values. SFE decreased after addition of 0.18% and 0.33% AgNP. Growth inhibition of S. mutans in liquid media was obtained after silver addition (p<0.05).Conclusions The addition of AgNP solutions to Transbond™ XT adhesive primer inhibited S. mutans growth. SBS, DC, and SFE values decreased after incorporation up to 0.33% AgNP solution without compromising the chemical and physical properties of the adhesive.

Collares FM, Portella FF, Rodrigues SB, Celeste RK, Leitune VCB, Samuel SMW. The influence of methodological variables on the push-out resistance to dislodgement of root filling materials: a meta-regression analysis. International Endodontic Journal, 49, 836-849, 2016. The aim of this systematic review was to evaluate the influence of several methodological variables on the push-out resistance to dislodgment of root filling materials by a meta-regression analysis of the literature. A systematic review was performed by searching the PubMed database using the terms 'push-out' and 'pushout'. Laboratory studies published before March 2015 were included. Two reviewers extracted data regarding country of origin, year of publication, tooth type, smear layer removal, root canal sealer, core material, obturation technique, sample storage, tooth portion, test machine load velocity and slice thickness. Pooled mean resistance to dislodgement of all groups from the included studies was used in a linear meta-regression of random effects (a = 0.05). Of the 850 identified studies, 53 met the inclusion criteria. A meta-regression of the 341 groups extracted from these articles was performed to analyse the influence of each variable on resistance to dislodgement (in MPa). The sealer, core material, obturation technique, slice thickness, storage time, load velocity and tooth portion significantly influence the results (P < 0.05). Irrigant solution and smear layer removal did not influence the resistance to dislodgement of the root filling materials (P > 0.05). Methodological variables such as sealer, core material, root filling technique, tooth type, tooth portion, slice thickness, storage time and load velocity influenced the resistance to dislodgment. The inclusion and standardization of all related variables could lead to a more comparable and reproducible analysis of the resistance to dislodgment of the root canal sealers.

After 6 months, chlorhexidine application did not effectively arrest bond strength degradation of fiber posts cemented in human roots.