Bjørn Frode Hansen

Effects from pretreatment of stannous fluoride versus sodium fluoride on enamel exposed to 0.1 M or 0.01 M hydrochloric acid.

Preventing enamel erosions caused by acidic soft drinks or from vomiting during eating disorders is a challenge in current dental research. The aim of this study was to examine whether pretreatment of dental enamel with a solution of 0.4% SnF2 could prevent dissolution of human enamel exposed to solutions of 0.1 M HCl, pH 1.2 or 0.01 M HCl at pH 2.2. Human enamel was pretreated for 18 h with a solution of 0.4% SnF2 and with control solutions of 2% NaF or distilled water, and then exposed to HCl solutions. Similar experiments were performed with teeth treated for 2 min SnF2 and then 4 min HCl. The effect was monitored by scanning electron microscopy (SEM) and by chemical analysis. At pH 2.2, NaF and water treatments showed minor inhibition of enamel dissolution, whereas SnF[Formula: See Text] inhibited demineralization significantly also after 2 min pretreatment and 4 min HCl exposure. At pH 1.2, SEM showed severe dissolution of the enamel surfaces regardless of pretreatment. As pH of stomach vomit is usually >1.5, SnF2 may be an interesting agent for use in the treatment and prevention of dental erosions even in patients with frequent vomiting episodes.

Prevalence and severity of vestibular recession in mandibular incisors after orthodontic treatment

OBJECTIVE To assess the prevalence and severity of vestibular gingival recession of mandibular incisors after orthodontic treatment and to evaluate possible contributing factors. MATERIALS AND METHODS From the record pool of patients who completed orthodontic treatment from 1999-2006 at the Department of Orthodontics, University of Oslo, Norway, 588 patients fulfilled the inclusion criteria. Intraoral color slides were used for the evaluation of gingival recessions (based on Miller classification), presence of visible plaque, and gingival inflammation. Cephalometric radiographs were used to assess the sagittal intermaxillary relation, mandibular and intermaxillary angles, and the position of the lower incisors. A control group was drawn from the same pool of 588 patients. All statistical analyses were performed using SPSS. RESULTS The prevalence of gingival recessions after orthodontic treatment was 10.3%. Most (8.6%) were classified as Miller Class I, and 1.7% were classified as Miller Class II. Gingival recession was predominantly found on central incisors. Reduction of the sagittal intermaxillary angle and retroclination of the lower incisors was correlated with the development of a more severe gingival recession. CONCLUSIONS The present study indicates that vestibular gingival recession of mandibular incisors after orthodontic treatment is of minor prevalence and severity. The presence of gingival recession or retroclination of the incisors with mesial basal relations increases the risk of more severe gingival recession.

A randomized, single‐blind, parallel‐group clinical study to evaluate the effect of soluble β‐1,3/1,6‐glucan on experimental gingivitis in man

BACKGROUND Gingivitis is an inflammatory disorder of the periodontium induced by dental plaque bacteria. Soluble beta-1,3/1,6-glucan (SBG) is known to enhance infection defense by preventing excessive inflammatory responses caused by bacterial endotoxins. AIM The aim of the present study was to investigate the effect of SBG on experimental gingivitis in man. MATERIAL AND METHODS Experimental gingivitis was induced over a period of 24 days in 30 healthy volunteers who were simultaneously treated with SBG. Two groups (n=10/group) rinsed twice daily with an SBG mouthwash that was either swallowed or expectorated. A third group (n=10) received a water rinse as a control. Plaque index (Pl.I), gingival index (GI), and amount of gingival crevicular fluid (GCF) were assessed at baseline and at six times during the study. RESULTS The results showed that in the SBG groups, GCF decreased significantly during the study. The swallow group experienced a significant increase in GCF during the first week. The control group followed the expected pattern of experimental gingivitis, with a significant increase in the gingival fluid secretion during the test period. There was a significant increase in GI and Pl.I during the study for all groups, with no significant differences between them. No adverse effects of SBG were recorded. CONCLUSIONS In this 24-day experimental gingivitis study of subjects who used either a SBG or a control mouthrinse: (1) all subjects had increased plaque and gingivitis, (2) GCF increased in control-rinse subjects and GCF decreased in SBG-rinse subjects. The only statistically significant difference between the SBG-rinse and control-rinse subjects was an increase in GCF at day 7 for subjects who rinsed and swallowed SBG.

Colony morphologies, species, and biotypes of yeasts from thrush and denture stomatitis

Objective. To study the species and phenotypic characteristics of yeasts, i.e. colony morphology, biotypes, and biotype relatedness, and the oral distribution of yeasts, in thrush and denture stomatitis.Material and Methods. Yeast colony morphology was observed under a stereo-microscope and photographed with a digital camera. Genus, species, and biotypes of the yeast isolates were identified by using a commercial kit, ID 32C. Yeast biotype dendrograms were generated by Spotfire software and SPSS 15.0 for Windows. Results. Multiple colony morphologies were observed among the yeasts from both thrush and denture stomatitis. One genus, 6 species, and 21 biotypes were identified among the yeasts from thrush, while 2 genera, 7 species, and 20 biotypes were identified among the yeasts from denture stomatitis. Considerable similarities in predominant species, biotypes, and biotype clustering profiles were shown among the yeasts from thrush and denture stomatitis. However, Candida dubliniensis was identified exclusively in subgingival areas and biotype 7347340215 of C. albicans was identified more frequently in palate and sulci in thrush. Conclusions. A diversity of species and phenotypes was found among the yeasts in thrush and denture stomatitis. Candidal commensals were predominant in thrush and denture stomatitis, but the observation of divergent Candida species and biotypes, constituting 23% of all the yeast isolates, should not be ignored.

The plaque- and gingivitis-inhibiting capacity of a commercially available essential oil product. A parallel, split-mouth, single blind, randomized, placebo-controlled clinical study

Abstract Background. Studies have reported commercially available essential oils with convincing plaque and gingivitis preventing properties. However, no tests have compared these essential oils, i.e. Listerine®, against their true vehicle controls. Objective. To compare the plaque and gingivitis inhibiting effect of a commercially-available essential oil (Listerine® Total Care) to a negative (22% hydro-alcohol solution) and a positive (0.2% chlorhexidine (CHX)) control in an experimental gingivitis model. Materials and methods. In three groups of 15 healthy volunteers, experimental gingivitis was induced and monitored over 21 days, simultaneously treated with Listerine® Total Care (test), 22% hydro-alcohol solution (negative control) and 0.2% chlorhexidine solution (positive control), respectively. The upper right quadrant of each individual received mouthwash only, whereas the upper left quadrant was subject to both rinses and mechanical oral hygiene. Plaque, gingivitis and side-effects were assessed at day 7, 14 and 21. Results. After 21 days, the chlorhexidine group showed significantly lower average plaque and gingivitis scores than the Listerine® and alcohol groups, whereas there was little difference between the two latter. Conclusion. Listerine® Total Care had no statistically significant effect on plaque formation as compared to its vehicle control.