The Erosive Potential of Different Malt Drinks: An in vitro and in situ study

2008 ◽  
Vol 33 (1) ◽  
pp. 35-37 ◽  
Author(s):  
Esber Çaglar ◽  
Sule Kavaloglu Cildir ◽  
Nuket Sandalli

Objectives: Whereas the potential effect of acidic drinks in the etiology of dental erosion is well recognized the role of malt drinks is unclear. The primary aim of the present study was to compare the in vitro erosive effect on enamel produced by different aromated malt drinks. A secondary objective was to compare their erosive effects in situ with those determined in vitro. Materials and methods: To select the malt drink for the study in situ, six commercially available malt drinks were examined for erosive potential in vitro. The study in situ was a single centre, 2-period, 2-treatment crossover study to compare the erosive effect of a commercially available malt drink (Test), with that of natural spring water (Control), over 10 day periods on 10 healthy volunteers. Subjects wore upper removable appliances containing two human enamel specimens from 9 a.m. to 4 p.m. The regimen of intake of the drinks was 250 ml at midday. Measurements of enamel loss were made on samples after 5 and 10 days by profilometry. Results: The in situ study showed a statistically significant difference in erosive potential between the test and control beverages. No specimen exposed to the control beverage displayed appreciable erosion. Erosion occurred with the test drink, but to a variable degree between subjects. Conclusions: Malt drinks should be considered as potentially erosive as the results for enamel specimens exposed to the test beverage in the clinical study showed a degree of erosion that varied greatly between different participants. It is likely that under these conditions an increase in the degree of erosion would be observed in children and young people who consume malt drinks.

2003 ◽  
Vol 131 (3-4) ◽  
pp. 156-162 ◽  
Author(s):  
Jelica Vukicevic ◽  
Jasmina Jankicevic

Trichomoniasis is frequent, parasitic and sexually transmitted infection of genitourinary tract. It is treated by metronidazole (5-nitroimidazole) according to protocol recommended by Center for Disease Control (CDC formerly called: Communicable Disease Center) [19]. The resistance of Trichomonas vaginalis (TV) strains to metronidazole (MND) was described in USA in 1960, and later on in many European countries [8, 9, 10, 11, 12, 13]. In these cases, due to persistent trichomonas infection, it is necessary to repeat MND treatment with moderate modification of dose and/or length of its application. Nevertheless, oncogenic and toxic effects of MND have to be taken into consideration. OBJECT The aim of this study was to investigate and analyze the incidence of TV in STD and lower susceptibility of certain TV strains to MND were analyzed. MATERIAL AND METHODS In three-year period (1999-2001) 612 patients (244 females and 368 males) suspected of STD were examined clinically and microbiologically at the Institute of Dermatovenereology in Belgrade. The patients detected for TV were treated according to CDC protocol. The affected were considered cured if there was no manifest clinical infection, and no TV verified by microbiological test. Results TV was isolated in 216 patients (35.29 % of all subjects). Trichomonas infection was found in 90 (36.88 %) out of 244 tested females and in 126 (32.34 %) of 368 males. Clinically manifested infection, with extensive urethral and vaginal secretion, was recorded in 161 patients, while the asymptomatic form was found in 55 subjects. This result indicates the predominance of manifested trichomonas infections (75.54 % of cases). The difference of distribution of clinical forms of trichomoniasis, in relation to sex, was not statistically significant (c2=0.854; p>0.05). The patients with verified trichomonas infection were treated by metronidazole according to CDC protocol. The recommended therapeutical scheme consisted of three phases proceeding in succession, in so far TV had not been eliminated by previous one. The number of cured patients, according to therapeutical phases, was shown in Table 4. Three patients (1.39 %, 2 males and 1 female) were not cured in spite of all three completed phases of therapeutical protocol. In all three cases, TV was eliminated by MND application in dose of 3 g/daily, during two days. The failure of minute MND treatment was analyzed in relation to clinical forms of the infection (manifested or asymptomatic), as well as in relation to types of infection (single- or associated infection). The incidence of refractory trichomoniasis treated by a single metronidazole dose of 2 g was significantly higher in the group of patients with polyinfection (c2=18.270 p<0.01). There was no significant difference of resistance to a single MND dose between the groups with manifested and asymptomatic trichomoniasis (c2=0.321; p<0.01). The prevalence of TV in vaginal and urethral smears indicates the significant incidence of trichomoniasis in STD. TV was more frequently isolated in patients with clinically manifested infection. TV susceptibility to MND was tested in vitro in aerobic and anaerobic conditions. The resistance of strains under in vitro conditions did not correlate with refractory feature of trichomoniasis to MND application [7 17, 18]. The success of trichomoniasis treatment depends upon multiple factors, including: a) TV susceptibility to drug, b) intravaginal redox potential, c) drug concentration in situ, d) associated microorganisms that may modify the amount of the drug available in situ [7, 18, 21]. The results of our investigation argue for the latter item, verifying that TV resistance to MND is higher in patients with polyinfection in relation to those with monoinfection (significant difference, c2=18.270; p<0.01). Repeated administration of low metronidazole doses may prolong the therapy of trichomonas infections, while application of high doses (over 3 g/day) may result in undesired complications. Given the well-known fact that repeated sublethal doses induce the resistance, would it be more beneficial to begin with slightly higher metronidazole dose (3 g/day) during short period of time (3-5 days)? This will be the subject of our further investigation.


2013 ◽  
Vol 38 (2) ◽  
pp. 142-150 ◽  
Author(s):  
LE Tam ◽  
P Bahrami ◽  
O Oguienko ◽  
H Limeback

SUMMARY Purpose Although damage to the structural integrity of the tooth is not usually considered a significant problem associated with tooth bleaching, there have been some reported negative effects of bleaching on dental hard tissues in vitro. More studies are needed to determine whether the observed in vitro effects have practical clinical implications regarding tooth structural durability. Objectives This in situ study evaluated the effect of 10% and 15% carbamide peroxide (CP) dental bleach, applied using conventional whitening trays by participants at home, on the fracture toughness of dentin. Methods Ninety-one adult volunteers were recruited (n ≈ 30/group). Compact fracture toughness specimens (approximately 4.5 × 4.6 × 1.7 mm) were prepared from the coronal dentin of recently extracted human molars and gamma-radiated. One specimen was fitted into a prepared slot, adjacent to a maxillary premolar, within a custom-made bleaching tray that was made for each adult participant. The participants were instructed to wear the tray containing the dentin specimen with placebo, 10% CP, or 15% CP treatment gel overnight for 14 nights and to store it in artificial saliva when not in use. Pre-bleach and post-bleach tooth color and tooth sensitivity were also evaluated using ranked shade tab values and visual analogue scales (VASs), respectively. Within 24–48 hours after the last bleach session, the dentin specimens were tested for fracture toughness using tensile loading at 10 mm/min. Analysis of variance, Kruskal-Wallis, χ2, Tukey's, and Mann-Whitney U tests were used for statistical analysis. The level of significance was set at p&lt;0.05 for all tests, except for the Mann-Whitney U tests, which used a Bonferroni correction for post hoc analyses of the nonparametric data (p&lt;0.017). Results The placebo, 10% CP, and 15% CP groups contained 30, 31, and 30 participants, respectively. Mean fracture toughness (+ standard deviation) for the placebo, 10% CP, and 15% CP groups were 2.3 ± 0.9, 2.2 ± 0.7, and 2.0 ± 0.5 MPa*m1/2 respectively. There were no significant differences in mean fracture toughness results among the groups (p=0.241). The tooth sensitivity VAS scores indicated a significantly greater incidence (p=0.000) and degree of tooth sensitivity (p=0.049 for VAS change and p=0.003 for max VAS) in the bleach groups than in the placebo group. The color change results showed generally greater color change in the bleach groups than in the placebo group (p=0.008 for shade guide determination and p=0.000 for colorimeter determination). Conclusions There were no significant differences in in situ dentin fracture toughness results among the groups. The results of this study provide some reassurance that dentin is not overtly weakened by the bleaching protocol used in this study. However, the lack of a statistically significant difference cannot be used to state that there is no effect of bleach on dentin fracture toughness.


2020 ◽  
Vol 46 (2) ◽  
pp. 163-171
Author(s):  
Cecília Alves de Sousa ◽  
Maria Beatriz Bello Taborda ◽  
Gustavo Antônio Correa Momesso ◽  
Eduardo Passos Rocha ◽  
Paulo Henrique dos Santos ◽  
...  

The purpose of this systematic review was to evaluate the literature available for materials exhibiting the best efficacy in preventing biofilm formation in the interior of implants. We searched PubMed/MEDLINE, Scopus, and Cochrane databases. This review is registered with the PROSPERO database and followed the suitability of the PRISMA protocol. The initial search resulted in 326 articles from the databases. After they were read, 8 articles remained, and the inclusion and exclusion criteria were applied. Six of these 8 articles were classified as in vitro and 2 were classified as in situ. The regions of the implants evaluated ranged from the interface of the pieces to the occlusal upper access of the abutment. The implant connections evaluated the Morse taper, external connection, and internal connection. Meta-analysis of the quantitative data was performed at a significance level of .05. Cotton exhibited poor control of infiltration, even in combination with other materials. Isolated gutta-percha (GP) and polytetrafluoroethylene (PTFE) tape with composite resin (CR) or GP performed better as physical barriers. The best results for chemical barriers were observed by the application of 1% chlorhexidine gluconate (CG) gel, thymol varnish, and the deposition of Ag films onto the surface. The applied meta-analysis did not show a significant difference in comparison between the different types of implant connections (P &gt; .05). The application of CG and thymol varnish antimicrobials was effective in preventing biofilm formation and easy clinical execution; these could be used in combination with CR, GP, and PTFE.


2006 ◽  
Vol 20 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Daniela Rios ◽  
Heitor Marques Honório ◽  
Ana Carolina Magalhães ◽  
Marília Afonso Rabelo Buzalaf ◽  
Regina Guenka Palma-Dibb ◽  
...  

This study assessed the surface softening and abrasive wear of eroded bovine enamel with or without the influence of toothbrushing. Five volunteers took part in this in situ study of 5 days. They wore acrylic palatal appliances containing 6 bovine enamel blocks divided in two rows with 3 blocks, which corresponded to the studied groups: erosion without toothbrushing (GI) and erosion with toothbrushing (GII). The blocks were subjected to erosion by immersion of the appliances in a cola drink for 10 minutes, 4 times a day. After that, no treatment was performed in one row (GI), whereas the other row was brushed (GII). The appliance was then replaced into the mouth. Enamel alterations were determined using profilometry and microhardness tests. Data were tested using paired Student’s t test (p < 0.05). The mean wear values (µm) and percentage of superficial microhardness change (%SMHC) were respectively: GI - 2.77 ± 1.21/91.61 ± 3.68 and GII - 3.80 ± 0.91/58.77 ± 11.47. There was a significant difference in wear (p = 0.001) and %SMHC (p = 0.001) between the groups. It was concluded that the wear was more pronounced when associated to toothbrushing abrasion. However, toothbrushing promoted less %SMHC due to the removal of the altered superficial enamel layer.


2009 ◽  
Vol 131 (11) ◽  
Author(s):  
Saeema Ahmed ◽  
Bo T. Christensen

This paper describes a study to understand the use of analogies by design engineers with different levels of experience in an adaptive design domain. Protocol analyses of 12 design engineers have been analyzed to understand the functions and reasoning of the analogies. The protocols are real-world data from the aerospace industry. The findings indicate a significant difference in both the use of analogies by novices and experienced designers and the reasoning from the analogies. Novices were found to predominantly transfer information related to the geometric properties without explicit reference to relevant design issues or to the appropriateness of applying the analogy, whereas experienced designers tended to use analogies for problem solving and problem identification. Experienced designers were found to use the analogy to reason about the function of a component and the predicted behavior of the component, whereas the novices seem to lack such reasoning processes.


2016 ◽  
Vol 50 (2) ◽  
pp. 111-116 ◽  
Author(s):  
Luiza P.S. Cassiano ◽  
Senda Charone ◽  
Juliana G. Souza ◽  
Ligia C. Leizico ◽  
Juliano P. Pessan ◽  
...  

This study analysed in vitro the effect of milk against dental erosion, considering three factors: the type of milk (bovine whole/fat-free), the presence of different fluoride concentrations and the time of application (before/after erosive challenge). Bovine enamel (n = 15/group) and root dentine (n = 12/group) specimens were submitted to the following treatments: after the first erosive challenge - 0.9% NaCl solution (negative control), whole milk with 0, 2.5, 5.0 and 10.0 ppm F, fat-free milk with 0, 2.5, 5.0 and 10.0 ppm F, and 0.05% NaF solution (positive control); before the first erosive challenge - whole milk with 0, 2.5, 5.0 and 10.0 ppm F, fat-free milk with 0, 2.5, 5.0 and 10.0 ppm F, and 0.05% NaF solution (positive control). Specimens were submitted to demineralisation-remineralisation regimes 4 times/day for 5 days. The response variables were enamel and dentine loss (in micrometres). Data were analysed using Kruskal-Wallis/Dunn's test (p < 0.05). For enamel, whole milk containing 10 ppm F, applied before the erosive challenge, was the most protective treatment, but with no significant difference compared with the same treatment carried out after the erosive challenge. For dentine, whole fluoridated milk (all concentrations, after), fat-free 10 ppm F milk (after, before) and whole milk with or without F (except 2.5 ppm F, all before) significantly reduced dentine erosion. It seems that the presence of fluoride, especially at 10 ppm, is the most important factor in reducing dental erosion.


2016 ◽  
Vol 50 (1) ◽  
pp. 78-86 ◽  
Author(s):  
Graziela Ribeiro Batista ◽  
Carlos Rocha Gomes Torres ◽  
Beatrice Sener ◽  
Thomas Attin ◽  
Annette Wiegand

The aim of this study was to evaluate the erosion-preventive effect of different artificial saliva formulations and human saliva in vitro compared to human saliva in situ. In the in vitro experiment, bovine enamel and dentin specimens were stored in artificial saliva (4 different formulations, each n = 20), deionized water (n = 20) or human saliva (n = 6 enamel and dentin specimens/volunteer) for 120 min. In the in situ experiment, each of the 6 enamel and dentin specimens was worn intraorally by 10 volunteers for 120 min. The specimens were then eroded (HCl, pH 2.6, 60 s). Half of the specimens were subjected to microhardness analysis (enamel) and the determination of calcium release into the acid (enamel and dentin), while the other half were again placed in the respective medium or worn intraorally, respectively, for 120 min before a second erosion was performed. Knoop microhardness of enamel and the calcium release of enamel and dentin into the acid were again determined. Statistical analysis was conducted by two-way repeated-measures ANOVA or two-way ANOVA (α = 0.05). Enamel microhardness was not significantly different between all test groups after the first and the second erosive challenge, respectively. Enamel calcium loss was significantly lower in situ compared to the in vitro experiment, where there was no significant difference between all test groups. Dentin calcium loss was significantly lower than deionized water only after the first and than all except one artificial saliva after the second erosion. Under the conditions of this experiment, the use of artificial saliva formulations and human saliva in vitro does not reflect the intraoral situation in dental erosion experiments adequately.


2021 ◽  
Vol 35 ◽  
Author(s):  
Maria Denise Rodrigues DE MORAES ◽  
Vanara Florêncio PASSOS ◽  
Gislaine Cristina PADOVANI ◽  
Lady Clarissa Brito da Rocha BEZERRA ◽  
Ilka Maria VASCONCELOS ◽  
...  

2015 ◽  
Vol 49 (5) ◽  
pp. 477-487 ◽  
Author(s):  
Marie-Theres Weber ◽  
Matthias Hannig ◽  
Sandra Pötschke ◽  
Franziska Höhne ◽  
Christian Hannig

Objectives: Antiadherent and antibacterial effects of certain plant extracts have been proven to be beneficial in preventive dentistry. In the present in situ/in vitro crossover study, the impact of plant extracts rich in polyphenols on the erosion-protective properties of the in situ pellicle was evaluated. Methods: Individual splints were prepared for 12 subjects for intraoral exposure of bovine enamel specimens. Following formation of a 1-min pellicle, watery plant extracts (leaves of the wild form of Ribes nigrum, the wild form of Origanum as well as a combination of both) were administered for 10 min in situ. Alternatively, a mouth rinse with fluorides (Elmex Kariesschutz) was performed for 1 min. After further oral exposure for 19/28 min, respectively, slabs were removed and incubated with HCl in vitro over 120 s (pH 2, 2.3, 3). The resulting calcium and phosphate release was quantified photometrically. Slabs with and without a 30-min in situ pellicle served as controls. The modification of pellicle ultrastructure was evaluated by transmission electron microscopy (TEM). Results: Plant extracts modulated the erosion-protective properties of the native in situ pellicle in all test groups in a pH-dependent manner. The combination of R. nigrum leaves and Origanum enhanced the protective properties of the pellicle at all pH values; the administration of this preparation was comparable, yet superior, to the effect of the fluoridated mouth rinse. TEM images indicated that rinsing with R. nigrum leaves/Origanum yielded a distinctly thicker and more electron-dense pellicle. Conclusion: The combination of certain plant extracts offers a novel approach to the complementary prevention of dental erosion.


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