Risk Factors for Dental Erosion After Bariatric Surgery: A Patient Survey.

INTRODUCTION: Treatment of obesity by bariatric surgery has increased in recent years. Reported side effects that may predispose to dental erosion include reflux, vomiting, and an increased frequency of intake of food and drink. OBJECTIVE: The aim was to investigate long-term dietary behaviour and experiences related to symptoms of dental erosion at least 5 years after bariatric surgery. METHODS: An online questionnaire study was conducted amongst 250 patients who had undergone bariatric surgery at King Saud Medical City in Saudi Arabia 5 years ago or more. It comprised 36 questions on demographic data, dietary habits, general health, dental health, and oral symptoms. The data were analysed using Chi-square and sign tests (significance level P < .05). RESULTS: A significant increase in acidic reflux and vomiting was found after bariatric surgery and appeared to increase with time after surgery. Also, a significant association between presence of acidic reflux and symptoms of dental erosion was found. However, 68.5% reported improved overall well-being after surgery. The response rate was 21.6% (most were female, aged 30-59 years). Respondents were generally not advised to visit a dentist in connection with bariatric surgery. CONCLUSIONS: This long-term cross-sectional study suggests a time-dependent, increasing occurrence of vomiting and acidic reflux after bariatric surgery. Vomiting and reflux became even more common after 5 to 10 years. A significant relationship emerged between a high frequency of acidic reflux and a high frequency of oral symptoms related to dental erosion. Daily occurrence of general symptoms related to dumping syndrome were reported by the majority. However, in a 5- to 10-year perspective, general symptoms related to dumping syndrome and symptoms from dental erosion did not seem to detract from the respondents' overall satisfaction with daily living. Oral health problems might be reduced if patients who had bariatric surgery were referred to a dentist for prevention and monitoring.

Salivary fluoride concentration and retention after rinsing with 0.05 and 0.2% sodium fluoride (NaF) compared with a new high F rinse containing 0.32% NaF.

OBJECTIVE: To compare salivary fluoride (F) concentration and F retention after rinsing with a new 0.32% sodium fluoride (NaF) rinse and conventional 0.05 and 0.2% NaF rinses. METHODS: Seventeen subjects (aged 22-26 years), with normal salivary secretion rates, participated in a double blind, cross-over study. In three separate sessions with a minimum washout period of 48 h, they rinsed for 1 min with 10 ml of 0.05, 0.2 or 0.32% NaF mouthrinse. Unstimulated whole saliva was collected before (baseline: 0 min) and after 1, 3, 5, 10, 20, 30, 45 and 60 min. The F concentration was plotted against time, and the area under the curve (AUC) calculated. Salivary F concentration and F retention for the three mouthrinses were compared by a randomized block test, followed by Tukey's test and a paired 2-tailed test. RESULTS: There was a clear dose-response for AUC 3-60 min; 0.32% > 0.2% > 0.05% (p < .05). The mean F retention was 0.25 mg for 0.05% NaF, 0.86 mg F for 0.2% Na and 1.31 mg F for 0.32% NaF, (p < .05). CONCLUSIONS: The higher salivary F concentration over time and the higher F retention after rinsing with an 0.32% NaF solution suggests a potential application in prevention of caries and dental erosion.

Effect of fluoridated milk on enamel demineralization adjacent to fixed orthodontic appliances.

OBJECTIVE: To investigate the effect of daily intake of fluoridated milk on enamel demineralization adjacent to fixed orthodontic brackets assessed with quantitative light-induced fluorescence (QLF). MATERIALS AND METHODS: Sixty-four healthy adolescents (13-18 years) undergoing orthodontic treatment with fixed appliances were enrolled and randomly allocated to a randomized controlled trial with two parallel groups. The intervention group was instructed to drink one glass of milk (≈ 200 ml) supplemented with fluoride (5 ppm) once daily and the subjects of the control group to drink the same amount of milk without fluoride. The intervention period was 12 weeks and the end-point was mineral gain or loss in enamel, assessed by QLF on two selected sites from each individual. The attrition rate was 12.5% and 112 sites were included in the final evaluation. RESULTS: There was no statistically significant difference between the groups concerning fluorescence (ΔF) values and lesion area (A mm(2)) at baseline. After 12 weeks, a significant decrease (p < 0.05) in ΔF was registered in the fluoridated milk group and a significant increase in the non-fluoride control group (p < 0.05). The mean reduction in the test group was somewhat lower (14%) than the increase in the control group (18%), but individual variations were evident. Only minor alterations of lesion area were recorded over the 12-week period and no statistically significant differences compared with baseline were found in any of the groups. CONCLUSION: Daily intake of fluoridated milk may aid remineralization of white spot lesions adjacent to fixed orthodontic appliances.

Effect of topical applications of a novel chlorhexidine-thymol varnish formula on mutans streptococci and caries development in occlusal fissures of permanent molars.

OBJECTIVE: To evaluate the effect of a new formula of a chlorhexidine-thymol varnish on mutans streptococci (MS) colonization and fissure caries development. METHODS: The study group consisted of 58 healthy adolescents (12-17 years old) undergoing orthodontic treatment with fixed appliances. A double-blind split-mouth design was applied, and 116 pairs of molar teeth were randomly assigned to topical varnish applications with either the new Cervitec Plus or its predecessor Cervitec. Both varnishes contained 1% CHX and 1% thymol (CHX/T) as active ingredients, but differed with respect to adhesive properties. The varnishes were applied in the fissures at baseline, and then every sixth week throughout the 48-week study period. Endpoints were MS colonization (CRT test) and occlusal laser fluorescence (LF, DIAGNOdent) recordings carried out regularly during follow-up. RESULTS: A significant reduction in the levels of MS in the fissures after the initial treatment was displayed with both varnishes (p < 0.05), and the levels remained consistently suppressed throughout the follow-up period. A non-significant but clear tendency was noted in favor of the new formula after six and 12 weeks, with fewer teeth harboring high counts (> or = 10(5) CFU) of MS (6w:12% vs. 24%, 12w:16% vs. 26%). No new lesions were registered in any subject, and the mean LF recordings did not change significantly over time in the groups. CONCLUSION: There were no statistically significant differences between the CHX/T varnishes in terms of bacterial growth and caries prevention. For MS suppression, a tendency towards an initially superior effect was displayed with the new formula.

Elevated levels of kynurenic acid change the dopaminergic response to amphetamine: implications for schizophrenia.

Kynurenic acid (KYNA) is an endogenous compound implicated in the pathophysiology of schizophrenia. This tryptophan metabolite antagonizes both the N-methyl-D-aspartate (NMDA) receptors and the nicotinic alpha7* receptors at micromolar concentrations. In the present study the effects of amphetamine on dopamine (DA) release in the nucleus accumbens and on firing of DA neurons in the ventral tegmental area (VTA) were investigated in rats treated with kynurenine, the precursor of KYNA, in order to elevate brain KYNA levels. In rats subchronically treated with kynurenine (90 mg/kg x d for 6 d via osmotic minipumps, resulting in a 2-fold increase in whole-brain KYNA), the amphetamine-induced (2 mg/kg i.p.) increase in accumbal DA release was clearly enhanced compared to controls. Furthermore, subchronic treatment with kynurenine reduced the inhibitory action of amphetamine (0.2-25.6 mg/kg i.v.) on firing rate and burst firing activity of VTA DA neurons. A single dose of kynurenine (5 mg/kg s.c., 60 min, resulting in a 3-fold increase in whole-brain KYNA) did not alter the amphetamine-induced effects on DA neurotransmission compared to control rats. Present data are in agreement with the increased striatal DA release by amphetamine as observed by brain-imaging studies in patients with schizophrenia. Thus, subchronic elevation of rat brain KYNA, may rationally serve as an animal model similar to a pathophysiological condition of schizophrenia. It is proposed that the reduced responsivity of VTA DA neurons to the inhibitory action of amphetamine observed in rats with subchronically elevated KYNA levels may partly account for the increase in terminal DA release.

Protective role of reactive astrocytes in brain ischemia.

Reactive astrocytes are thought to protect the penumbra during brain ischemia, but direct evidence has been lacking due to the absence of suitable experimental models. Previously, we generated mice deficient in two intermediate filament (IF) proteins, glial fibrillary acidic protein (GFAP) and vimentin, whose upregulation is the hallmark of reactive astrocytes. GFAP(-/-)Vim(-/-) mice exhibit attenuated posttraumatic reactive gliosis, improved integration of neural grafts, and posttraumatic regeneration. Seven days after middle cerebral artery (MCA) transection, infarct volume was 210 to 350% higher in GFAP(-/-)Vim(-/-) than in wild-type (WT) mice; GFAP(-/-), Vim(-/-) and WT mice had the same infarct volume. Endothelin B receptor (ET(B)R) immunoreactivity was strong on cultured astrocytes and reactive astrocytes around infarct in WT mice but undetectable in GFAP(-/-)Vim(-/-) astrocytes. In WT astrocytes, ET(B)R colocalized extensively with bundles of IFs. GFAP(-/-)Vim(-/-) astrocytes showed attenuated endothelin-3-induced blockage of gap junctions. Total and glutamate transporter-1 (GLT-1)-mediated glutamate transport was lower in GFAP(-/-)Vim(-/-) than in WT mice. DNA array analysis and quantitative real-time PCR showed downregulation of plasminogen activator inhibitor-1 (PAI-1), an inhibitor of tissue plasminogen activator. Thus, reactive astrocytes have a protective role in brain ischemia, and the absence of astrocyte IFs is linked to changes in glutamate transport, ET(B)R-mediated control of gap junctions, and PAI-1 expression.

Effect of a dental cream containing amorphous cream phosphate complexes on white spot lesion regression assessed by laser fluorescence.

PURPOSE: To investigate and compare the effects of a dental cream containing complexes of casein phosphoprotein-amorphous calcium phosphate (CPP-ACP) and fluoride mouthwashes on the regression of white spot lesions (WSL). MATERIALS AND METHODS: The study group consisted of 26 healthy adolescents (mean age 14.6 years) exhibiting 60 teeth with 152 visible WSL sites on incisors and canines immediately after debonding of fixed orthodontic appliances. After bracket removal, professional tooth cleaning and drying, a visual scoring (0-4) and laser fluorescence (LF) readings were carried out. The patients were randomly assigned to two different treatment protocols with the aim of remineralising the lesions: A) daily topical applications of a dental cream containing CPP-ACP (Topacal) for 3 months followed by a 3-month period of daily toothbrushing with fluoridated dentifrice, or B) daily 0.05% sodium fluoride mouthwash combined with fluoridated dentifrice for 6 months. The registrations were repeated after 1, 3, 6 and 12 months and follow-up data were compared with baseline with aid of chi-square and paired t-tests. RESULTS: A significant improvement of the clinical WSL-scores was found over time in both groups, but there was a statistically significant difference (p < 0.01) concerning the number of sites that totally disappeared after 12 months in favour of the CPP-ACP regime, 63% compared with 25% respectively. The clinical registrations were mirrored by a statistically significant decrease (p < 0.05) in the LF readings at the 6- and 12-month follow-ups compared with baseline. No significant differences were displayed between the groups. CONCLUSIONS: Clinical scoring and LF assessment suggested that both regimens could promote regression of WSL after debonding of fixed orthodontic appliances. The visual evaluation suggested an aesthetically more favourable outcome of the amorphous calcium phosphate treatments.

Population- vs. risk-based applications of fissure sealants in first permanent molars: a 13-year follow-up.

PURPOSE: To evaluate and compare the long-term outcome of a population-based and a risk-based strategy of applying fissure sealants in newly erupted first permanent molars. DESIGN AND SETTING: Retrospective cohort study in primary dental care. MATERIALS AND METHODS: Four hundred and ninety-six subjects from two cohorts were included. In group P (n = 236), routine applications of fissure sealants were conducted while sealants were placed on the basis of subjective criteria in Group R (n = 260). Data of applications, maintenance, decay, restorations, extractions, and cumulative time of applications from six to 19 years were extracted from the dental records and bite-wing radiographs by two of the authors simultaneously. The main outcome measures were the total caries prevalence at the age of 19 years as well as the fate of each sealed and non-sealed occlusal surface. RESULTS: In group P, 87.7% of all first permanent molars were sealed compared with 20.2% in group R. There was no statistically significant difference concerningthe total DFT at 19 years of age between the groups (mean 3.5 +/- 3.8 vs. 3.7 +/- 3.4). Considering the occlusal surfaces of the first permanent molars only, a statistically significant treatment effect was demonstrated in group P with an odds ratio of 4.6 (95% CI: 3.0 - 6.7; p < 0.05). The absolute risk reduction was 36.3% and the number needed to treat was 2.8. In Group R, no statistically significant treatment effect was disclosed (OR = 1.3; 95% CI: 0.9 - 1.7; risk reduction 5.5%). CONCLUSION: This 13-year follow-up showed that population-based applications of fissure sealants in first permanent molars shortly after eruption showed a statistically significant treatment effect on the occlusal surfaces at the age of 19 years, which was in contrast to findings from a cohort in which sealants were applied on the basis of an individual risk-based strategy. There were, however, no significant differences concerning the total caries experience between the two cohorts.

[Laboratory thyroid disease diagnosis--interdisciplinary cooperation. International consensus in Swedish perspective]. / Laboratoriemässig tyreoideadiagnostik --samarbete over disciplingränserna. Internationell konsensus i svenskt perspektiv.

In 2003, The National Academy of Clinical Biochemistry published a consensus monograph on thyroid tests (available via Internet from 2002). The document, a result of international collaboration, describes the pathophysiological background and clinical application of the measurements as well as principles for their technical performance. Of value, and of definite clinical relevance, is the detailed description of factors affecting the results in health and disease. However, we lack a description of the sometimes large differences in values obtained with different generally available methods, as well as a presentation of the occurrence and evaluation of analytical interference and related technical factors affecting results. Readers with little experience from quantitative measurement in the clinical laboratory, therefore, are not stimulated to obtain a better understanding of causes and evaluation of unexpected results.

Biomolecular reactions studied using changes in Brownian rotation dynamics of magnetic particles.

We have used magnetic particles to study specific binding of prostate specific antigen (PSA) to the surfaces of the bioparticles. The used particles have a mean diameter of about 130 nm and are placed in phosphate buffer saline (PBS). Each particle is composed of clusters of magnetic single domains of magnetite, which are covered with dextran. Changes in surface chemistry of the particles give rise to a change in the hydrodynamic volume of the particles. The later is mirrored by the changed frequency response of the complex magnetic susceptibility of a fluid containing these particles. Using ordinary induction coils and the lock-in amplifier technique it is possible to measure the complex magnetic susceptibility of the particle solution in a frequency range from about 10 Hz up to 10 kHz. From the measurement of the complex susceptibility versus the excitation frequency (both at the excitation frequency as well as at higher harmonics) we have shown that it is possible to quantitatively study the binding of PSA to the surfaces of the magnetic particles and thus to determine the PSA concentration in solution containing known concentration of nanoparticles functionalised with a monoclonal PSA antibody. Our method allows to perform an immunoassay in a single step and is much faster and cheaper compared to conventional ELISA procedures.

Effect of xylitol on mutans streptococci and lactic acid formation in saliva and plaque from adolescents and young adults with fixed orthodontic appliances.

This study aimed to investigate two dose regimens of xylitol-containing tablets on the ecology of dental plaque and saliva during treatment with fixed orthodontic appliances. The study group comprised 56 healthy patients (mean age 15.8 yr) randomly assigned into the following groups: A, (n = 23) two xylitol tablets two times a day (1.7 g xylitol d(-1)) for 18 wk; B, (n = 23) two tablets four times per day (3.4 g xylitol d(-1)) for 18 wk; and C, (n = 10) no tablets. The levels of mutans streptococci (ms) were enumerated in plaque and saliva and the proportion of xylitol-sensitive (X(S)) strains in saliva was determined by autoradiography with [(14)C]-xylitol at baseline and at 6, 12, and 18 wk. The lactic acid formation rate was assessed enzymatically in sucrose-challenged plaque suspensions. A drop in salivary ms levels was found in Group A after 6 wk but not after 12 or 18 wk. The proportion of X(S) ms was decreased after 6 wk in groups A and B and remained so during the experimental period. The lactic acid formation rates decreased slightly ( approximately 10%) in the two xylitol groups compared with baseline. In conclusion, our results showed that although an alteration of ms strains was demonstrated following a regular daily low-dose intake of xylitol, the long-term total ms counts in plaque and saliva as well as plaque acidogenicity remained unchanged.

Effect of topical applications of a chlorhexidine/thymol-containing varnish on fissure caries assessed by laser fluorescence.

The aim of this study was to monitor the effect of an antibacterial varnish using the readings of a caries-detecting device (DIAGNOdent) in fissures of young permanent molars. The material consisted of 32 healthy patients with a mean age of 14.1 years undergoing orthodontic treatment with fixed appliances. The inclusion criteria were presence of one homologous pair of 2nd upper or lower molars with clinically intact occlusal surfaces. A split-mouth study design was used in which the fissures were treated with either an antibacterial chlorhexidine/thymol-containing varnish or a placebo varnish every 6th week. The follow-up period was 42 weeks and laser fluorescence (LF) readings were carried out every 12th week. The mean LF values increased significantly (P < 0.05) after 24, 36, and 48 weeks compared to baseline following the placebo treatments but not after treatment with the active antibacterial varnish. During the study period, micro-cavities were diagnosed in two test-treated and five placebo-treated teeth. In conclusion, the results reinforce previous findings that frequent applications of a chlorhexidine/thymol-containing dental varnish might have a protective role in fissures of young permanent molars and that this could be monitored with a chair-side caries detecting LF device.

Effect of a triclosan-containing dental gel on the levels of prostaglandin I2 and interleukin-1beta in gingival crevicular fluid from adolescents with fixed orthodontic appliances.

The effect of a triclosan-containing (0.3%) dental gel on inflammatory mediators in gingival crevicular fluid (GCF) was evaluated in 14 healthy adolescents undergoing orthodontic treatment with fixed appliances. A double-blind randomized split-mouth study design was used with color-coded experimental and placebo gels. The gel was self-applied for 5 min twice daily for 14 days in custom-made soft plastic trays. Clinic al data (visible plaque index (VPI) and gingival bleeding index (GBI) and samples of GCF were collected at baseline and after 1, 2, 4, and 6 weeks. The concentrations of prostaglandin I2 (PGI2) and interleukin-1beta (IL-1beta were determined by radioimmuno- and enzyme-linked immunosorbent assays, respectively. No clinical effects of the gel applications regarding amount of plaque or gingival bleeding were unveiled. Neither the experimental nor the placebo gel applications caused any statistically significant alterations in the inflammatory mediators, PGI2 and IL-1beta, compared to baseline. In conclusion, the present study did not reveal any beneficial cffects of the triclosan-containing gel regimen on mild gingivitis in adolescents with fixed orthodontic appliances.

Autoradiography of opioid and ORL1 ligands in opioid receptor triple knockout mice.

Three genes for the opioid receptors ( micro, delta and kappa) and a gene coding for a related receptor (ORL1) have been cloned but pharmacological studies suggest that further subtypes exist that remain poorly understood. To determine if there are other classically defined opioid binding sites we have carried out homogenate binding and section autoradiography with [3H]naloxone in mice that lack all three opioid genes and are hyperalgesic in a thermal nociceptive test. We have also examined [3H]bremazocine labelling in triple knockout brain and spinal cord as this ligand has been proposed to label novel kappa-receptors. No receptor labelling for either ligand was detected in the brains or spinal cord of knockout mice demonstrating that all binding is the product of the three known receptors and that there is no cross-labelling of the ORL1 receptor. Nociceptin (1 micro m) caused marked displacement of [3H]bremazocine in wild-type brains indicating that nociceptin at high concentrations can displace classical opioid binding. As a number of studies have proposed a close association between the classical opioid receptors and the ORL1 system we also hypothesized that loss of all of the classical opioid receptors might lead to compensatory changes in ORL1 receptors. Labelling of the ORL1 receptor with [3H]nociceptin showed region-dependent quantitative increases in triple knockout brains indicating a close relationship between the two systems in specific brain areas.

Effect of a hydrophobic tooth coating on gingival health, mutans streptococci, and enamel demineralization in adolescents with fixed orthodontic appliances.

The effect of an anti-adhesive enamel coating on plaque accumulation, gingival health, and enamel demineralization was evaluated in 39 adolescents undergoing treatment with fixed orthodontic appliances using a prospective split-mouth design. Immediately after bracket insertion, the polymer was randomly applied after enamel etching to the buccal surfaces of the teeth in the left or right upper quadrant, leaving the opposite quadrant as an untreated control (218 test and 216 control teeth). Reapplications were carried out every 3rd month during the course or the study. The following data were collected at baseline and at designated follow-ups: visible plaque index, total viable counts and proportion of mutans streptococci in plaque samples, gingival bleeding index, and amount of gingival crevicular fluid. The incidence of enamel demineralization adjacent to the appliances was scored clinically at the termination of the orthodontic treatment. The observation time ranged from 6-24 months, during which the participants used fluoride rinses and toothpaste daily. A slightly impaired gingival health and increased levels or mutans streptococci compared with baseline was disclosed during the treatment. Five subjects showed enamel demineralization on a total of 30 teeth at the time of de-bonding. The results indicated no statistically significant differences between the enamel-coated and untreated teeth with regard to the studied variables at any follow-up. In conclusion, the present findings did not support a clinically beneficial effect of the polymeric tooth coating in a low-caries group of adolescents treated with fixed orthodontic appliances.