Chlorhexidine markedly potentiates the oxidants scavenging abilities of Candida albicans.

The oxidant scavenging ability (OSA) of catalase-rich Candida albicans is markedly enhanced by chlorhexidine digluconate (CHX), polymyxin B, the bile salt ursodeoxycholate and by lysophosphatidylcholine, which all act as detergents facilitating the penetration of oxidants and their intracellular decomposition. Quantifications of the OSA of Candida albicans were measured by a highly sensitive luminol-dependent chemiluminescence assay and by the Thurman's assay, to quantify hydrogen peroxide (H2O2). The OSA enhancing activity by CHX depends to some extent on the media on which candida grew. The OSA of candida treated by CHX was modulated by whole human saliva, red blood cells, lysozyme, cationic peptides and by polyphenols. Concentrations of CHX, which killed over 95 % of Candida albicans cells, did not affect the cells' abilities to scavenge reactive oxygen species (ROS). The OSA of Candida cells treated by CHX is highly refractory to H2O2 (50 mM) but is strongly inhibited by hypochlorous acid, lecithin, trypan blue and by heparin. We speculate that similarly to catalase-rich red blood cells, Candida albicans and additional catalase-rich microbiota may also have the ability to scavenge oxidants and thus can protect catalase-negative anaerobes and facultative anaerobes cariogenic streptococci against peroxide and thus secure their survival in the oral cavity.

[Are you afraid of open bite?].

Treatment of open bite malocclusion is a challenge for both the orthodontist and the patient. The key to successful treatment are careful evaluation, that leads to correct diagnosis and treatment plan, as well as meticulous cooperation on behalf of the patient. There are many treatment options starting with follow up and orofacial myofunctional therapy, and concluding with orthosurgical correction. The tendency to relapse and reopening the bite must be emphasized to the patient before initiation of the orthodontic treatment. It is highly recommended in indicated cases to include orofacial myofunctional therapy in combination with the orthodontic treatment. New modalities of treatment give great promise for the future, and enable us to intrude posterior teeth using skeletal anchorage. However, it is still unknown whether these new treatment modalities will give better stability for open bite correction.

Recurrent aphthous stomatitis and thiamine deficiency.

Recurrent aphthous stomatitis is a disease of unknown cause. To examine whether thiamine (vitamin B1) deficiency is associated with recurrent aphthous stomatitis, we studied vitamin B1 levels in 70 patients with recurrent aphthous stomatitis and in 50 members of a control group. The vitamin B1 level was determined as thiamine pyrophosphate effect on transketolase activity in red blood cell lysates. Low levels of vitamin B1 were detected in 49 patients but in only two members of the control group (p < 0.0001). These low levels were not associated with patient age, sex, or underlying disease causing recurrent aphthous stomatitis. Our finding suggests an association between thiamine deficiency and recurrent aphthous stomatitis.