In-vivo durability of a fluoride-releasing sealant (OpalSeal) for protection against white-spot lesion formation in orthodontic patients

BACKGROUND: Sealant application during fixed appliances orthodontic treatment for enamel protection is common, however, reliable data on its durability in vivo are rare. OBJECTIVE: This study aims at assessing the durability of a sealant (OpalSeal, Ultradent) for protection against white-spot lesion formation in orthodontic patients over 26 weeks in vivo, taking into account the provision or absence of an adequate oral hygiene. We tested the null hypothesis of (1) no significant abatement of the sealant after 26 weeks in fixed orthodontic treatment compared to baseline, and (2) no significant influence of the factor of brushing and oral hygiene (as screened by approximal plaque index, API) on the abatement of the sealant. METHODS: Integrity and abatement of OpalSeal applicated directly following bracketing was assessed in thirty-six consecutive patients (n(teeth) = 796) undergoing orthodontic treatment with fixed appliances (male/female12/24; mean age/SD 14.4/1.33 Y). Assessment of the fluorescing sealant preservation was by a black-light lamp, using a classification that was concepted in analogy to the ARI index: (3, sealant completely preserved; 2= > 50% preserved; 1 = <50%; 0 = no sealant observable) immediately following application (Baseline, T0), after 2 (T1), 8 (T2), 14 (T3), 20 (T4) and 26 weeks (T5). API was assessed at T0 and T1. Statistical analysis was by non-parametric repeated measures ANOVA (α = 5%, power >80%). RESULTS: At baseline, 43.4% of teeth had a positive API. Oral hygiene deteriorated after bracketing (T1, 53%) significantly. Null hypothesis (1) was rejected, while (2) was accepted: Mean values of both the well brushed and non-brushed anterior teeth undercut the score “1” at T3 (week 14). Despite a slightly better preservation of the sealer before and after T3 in not-sufficiently brushed (API-positive) teeth, this finding was statistically not significant. CONCLUSION: One single application of OpalSeal is unlikely to last throughout the entire fixed appliance treatment stage. On average, re-application of the sealant can be expected to be necessary after 3.5 months (week 14) in treatment

The effect of organic matters on manganese oxidation

11th International Symposium on Environmental Pollution and Its Impact on Life in the Mediterranean Region -- OCT 06-10, 2001 -- LIMASSOL, CYPRUSIn oxygen-free aquatic environments, such as ground water or hypolimnetic waters of eutrophic lakes, manganese predominantly as Mn(II) and natural organic compounds like humic materials occur. The effects of tannic acid and acetic acid as representatives of organic material on stabilizing the transformation of Mn(II) to Mn(IV) in a two-stage batch system have been examined. In the first stage, the catalytic effect of Mn(IV) linearly increased up to about 300 mg/l, keeping Mn(II) constant at 25 mg/l. In the second stage it has been studied how oxidation of Mn(H) and the catalytic effect of Mn(IV) are affected by tannic and acetic acids. Tannic acid completely inhibited the oxidation of manganese and acetic acid had no observable effect on the oxidation reaction

Influence of intracoronary shunt on myocardial ischemic injury during off-pump coronary artery bypass surgery

PubMed: 23337405Aim. The aim of the study was to evaluate the role of intracoronary shunt during off-pump coronary artery bypass surgery in patients with isolated left anterior descending coronary artery lesion. Methods. Forty patients undergoing off-pump coronary artery bypass using the left internal mammary artery to bypass the left anterior descending coronary artery were randomly assigned to have the bypass performed with intracoronary shunt or by occlusive snaring. Potential damage from the shunt or from snaring was monitored by clinical follow-up, monitoring of cardiac enzymes (cardiac troponin I, CK, CK-MB), electrocardiography, and echocardiography before and 24 h. after the surgery. Left ventricular myocardial biopsies were performed during surgery for histopathological analysis. Results. None of the patients in this study died during or after the surgery. Duration of the anastomosis was significantly longer in the shunt group. No significant difference concerning the preoperative and postoperative CK levels between groups. The preoperative CK-MB levels of the groups were not significantly different, whereas postoperative levels was significantly lower in the shunt group. The preoperative troponin I levels of the groups were not significantly different, whereas postoperative levels was significantly higher in the snare group. Myocardial edema was significantly less in shunt group compared with snare group. There were no electrocardiographic abnormalities, severe CK-MB elevation, or hemodynamic deterioration after the operation in both groups. Conclusion. Intracoronary shunt may have beneficial effects due to the reduction of postoperative troponin I levels and myocardial edema during grafting of the left anterior descending coronary artery. However, further trials need to be performed for the documentation of their impacts precisely