Comparison of mineral trioxide aggregate and calcium hydroxide for apexification of immature permanent teeth: A systematic review and meta-analysis.

BACKGROUND/PURPOSE: Calcium hydroxide and mineral trioxide aggregate (MTA) are used for inducing a calcific barrier at an open tooth root (apexification). The purpose of this study was to compare the efficacy of calcium hydroxide and MTA for apexification of immature permanent teeth. METHODS: Medline, Cochrane, EMBASE, and Google Scholar were searched until November 24, 2015, using the keywords apexification, permanent teeth, MTA, and calcium hydroxide. RESULTS: Of 216 studies identified, four studies were included. There were no differences in the clinical success rate [pooled odds ratio (OR) = 3.03, 95% confidence interval (CI): 0.42-21.72, p = 0.271], radiographic success rate (pooled OR = 4.30, 95% CI: 0.45-41.36, p = 0.206), or apical barrier formation rate (pooled OR = 1.71, 95% CI: 0.59-4.96, p = 0.322) between calcium hydroxide and MTA groups. The time required for apical barrier formation was significantly less in the MTA group (pooled difference in means = -3.58, 95% CI: from -4.91 to -2.25, p < 0.001). CONCLUSION: While both materials provide similar success rates, the shorter treatment time with MTA may translate into higher overall success rates because of better patient compliance.

Mitochondria-Targeting Polydopamine Nanoparticles To Deliver Doxorubicin for Overcoming Drug Resistance.

Mitochondria play a critical role in diverse cellular processes, such as energy production and apoptosis regulation. The mitochondria-targeted drug delivery is becoming a potential novel strategy for overcoming drug resistance in cancer therapy. Herein, we synthesize nature-inspired dopamine-derived polydopamine (PDA) nanoparticles. Using triphenylphosphonium (TPP) as the mitochondrial penetration molecule to improve the target efficiency, we synthesize poly(ethylene glycol) (PEG)-modified PDA (PDA-PEG) and TPP-functionalized PEG-modified PDA (PDA-PEG-TPP) nanoparticles. Then anticancer drug doxorubicin (DOX) was loaded on PDA-PEG and PDA-PEG-TPP (PDA-PEG-DOX and PDA-PEG-TPP-DOX) nanoparticles, which are apt to deliver DOX to cell nuclei and mitochondria, respectively. To mimic the repeated anticancer drug treatment in clinical cases, we repeatedly treated the MDA-MD-231 cancer cells for a long time using DOX-loaded nanoparticles and find that the mitochondria targeting PDA-PEG-TPP-DOX has higher potential to overcome the drug resistance than the regular delivery nanoparticles PDA-PEG-DOX. These results indicate the promising potential of applying PDA-PEG-TPP-DOX nanoparticles in mitochondria-targeted drug delivery to overcome the drug resistance in long-time anticancer chemotherapy.