A Radical-Free Approach to Teeth Whitening

Background: Traditional bleaching agents based on hydrogen peroxide (HP) or carbamide peroxide (CP) have adverse soft and hard tissue effects. Objectives: This study tested a novel formulation of phthalimidoperoxycaproic acid (PAP) with additives to optimise its safety and effectiveness. Methods: A novel gel (PAP+) was formulated. Laboratory studies assessed effects of six 10-minute exposures to PAP+ vs. commercial CP and HP gels, using surface profilometry and microhardness. The effectiveness of PAP+ in vitro against complex polyphenol stains on enamel was compared to 6% HP. Results: Unlike HP gels, PAP+ gel did not erode enamel. Unlike both CP and HP gels, PAP+ gel did not reduce the surface microhardness of enamel. PAP+ gel on used on polyphenol stains was superior to 6% HP. In this model, six repeated 10-minute treatments with PAP+ gel could improve the shade by approximately eight VITA® Bleachedguide shades. Conclusions: These laboratory results support the safety and effectiveness of this new PAP formula and its use as an alternative to CP and HP with superior safety and effectiveness.

HIFU Varicose Vein Treatment Using Veinsound Device Feasibility Study On Sheep

The purpose of this nonclinical study was to evaluate the performance (in terms of vein occlusion) and the local tissue effects of echo-guided HIFU (High Intensity Focused Ultrasound) treatments in sheep’s saphenous veins.HIFU treatments were used to treat 4 saphenous veins. Two HIFU doses were evaluated 4s/60J and 7s/105J with and without tumescence injection in perivenous tissues. Before and after treatment, ultrasound scans were performed (at Day 0, 3, 7 and 21). Sheep were then euthanized at D21. Local tissue effects were evaluated based on the macroscopic observations, while the evaluation of the device performance was based on ultrasonic scan.Macroscopically throughout the study duration, for dose of 4s/60J and with tumescence, significant lumens diameter reduction of 84% was observed without skin burns. For doses of 4s/60J without tumescence and 7s/105J skin burns of slight to severe grade was observed along the vein, while no thrombus nor lumen reduction were observed.

Histopathological effects of electrosurgical interventions in an in vivo porcine model of colonic endoscopic mucosal resection

ObjectiveEndoscopic mucosal resection (EMR) in the colon has been widely adopted, but there is limited data on the histopathological effects of the differing electrosurgical currents (ESCs) used. We used an in vivo porcine model to compare the tissue effects of ESCs for snare resection and adjuvant margin ablation techniques.DesignStandardised EMR was performed by a single endoscopist in 12 pigs. Two intersecting 15 mm snare resections were performed. Resections were randomised 1:1 using either a microprocessor-controlled current (MCC) or low-power coagulating current (LPCC). The lateral margins of each defect were treated with either argon plasma coagulation (APC) or snare tip soft coagulation (STSC). Colons were surgically removed at 72 hours. Two specialist pathologists blinded to the intervention assessed the specimens.Results88 defects were analysed (median 7 per pig, median defect size 29×17 mm). For snare ESC effects, 156 tissue sections were assessed. LPCC was comparable to MCC for deep involvement of the colon wall. For margin ablation, 172 tissue sections were assessed. APC was comparable to STSC for deep involvement of the colon wall. Islands of preserved mucosa at the coagulated margin were more likely with APC compared with STSC (16% vs 5%, p=0.010).ConclusionFor snare resection, MCC and LPCC did not produce significantly different tissue effects. The submucosal injectate may protect the underlying tissue, and technique may more strongly dictate the depth and extent of final injury. For margin ablation, APC was less uniform and complete compared with STSC.