Browsing by Subject "caries"
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Item Determination of Caries Lesion Activity: Reflection and Roughness for Characterization of Caries Progression(2018) Ando, Masatoshi; Shaikh, S.; Eckert, George J.; Cariology, Operative Dentistry and Dental Public Health, School of DentistryCaries lesion progression is difficult to determine with visual and tactile examinations. The hypothesis of this study was that reflection and roughness measurements could determine caries progression. Ground/polished sound human enamel specimens were analyzed at baseline (sound) and after two four-day demineralization periods for reflection using optical reflectometry (ORef) and for roughness using optical surface profilometry (SPro). Specimens were demineralized using a microbial–Streptococcus mutans aries model. Comparisons among the periods for ORef and SPro were performed using repeated measures analysis of variance. Two-sample t-tests were used for differences in transverse microradiography. The integrated mineral loss and depth of the four-day demineralization period were significantly smaller than those for the eight-day demineralization period (p<0.01). With increased demineralization time, reflection was significantly decreased and roughness was significantly increased (p<0.01). Correlation between ORef and SPro was moderate (r=−0.63). Both reflection and roughness can be characterized for nondestructive longitudinal assessment of caries lesion progression.Item A Direct Refractory Die Technique for Cast Gold Restorations(2017-03) Smith, Cleveland T.; Diefenderfer, Kim E.; Cariology, Operative Dentistry and Dental Public Health, School of DentistryFabricating accurate cast gold restorations can be challenging for both clinicians and laboratory technicians. Removing the wax pattern from the master die often distorts the pattern, which, in turn, compromises the overall fit and marginal adaptation of the casting. This article demonstrates a laboratory technique in which the final restoration is cast directly on the refractory die without removing the wax pattern. Thus, distortion of the wax pattern is avoided, enabling the production of superbly fitting gold castings for both intracoronal and extracoronal restorations. Used by permission. © Operative Dentistry, Inc. Transmission or reproduction of protected items beyond that allowed by fair use requires the written permission of Operative Dentistry, IncItem Effect of phytate and zinc ions on fluoride toothpaste efficacy using an in situ caries model(Elsevier, 2018) Parkinson, Charles; Burnett, Gary R.; Creeth, Jon; Lynch, Richard; Budhawant, Chandrashekhar; Lippert, Frank; Hara, Anderson T.; Zero, Domenick T.; Cariology, Operative Dentistry and Dental Public Health, School of DentistryObjectives To compare and explore the dose-response of phytate-containing 1150 ppm fluoride toothpastes on model caries lesions and to determine the impact of zinc ions. Methods This was a single-centre, randomised, blinded (examiner/laboratory analyst), six-treatment, four-period crossover, in situ study in adults with a removable bilateral maxillary partial denture. Study treatments were toothpastes containing: 0.425% phytate/F; 0.85% phytate/F; 0.85% phytate/Zn/F; F-only; Zn/F and a 0% F placebo. Where present, F was 1150 ppm as NaF; Zn was 0.3% as ZnCl2. Human enamel specimens containing early-stage, surface-softened (A-lesions) or more advanced, subsurface (B-lesions) caries lesions were placed into the buccal flanges of participants’ modified partial denture (one of each lesion type per side). A-lesions were removed after 14 days of twice-daily treatment use; B-lesions were removed after a further 14 days. A-lesions were analysed for surface microhardness recovery. Both lesion types were analysed by transverse microradiography and for enamel fluoride uptake, with B-lesions additionally analysed by quantitative light-induced fluorescence. Comparison was carried out using an analysis of covariance model. Results Statistically significant differences between 1150 ppm F and the placebo toothpastes (p < 0.05) were shown for all measures, validating the model. No differences between fluoride toothpastes were observed for any measure with little evidence of a dose-response for phytate. Study treatments were generally well-tolerated. Conclusions Results suggest phytate has little impact on fluoride’s ability to promote early-stage lesion remineralisation or prevent more advanced lesion demineralisation in this in situ caries model. Similarly, results suggest zinc ions do not impair fluoride efficacy.Item Effect of toothbrushing duration and dentifrice quantity on enamel remineralisation: An in situ randomized clinical trial(Elsevier, 2016-12) Creeth, J. E.; Kelly, Sue A.; González-Cabezas, Carlos; Karwal, R.; Martinez-Mier, Esperanza A.; Lynch, R. J. M.; Bosma, M.; Zero, Domenick T.; Department of Cariology, Operative Dentistry and Dental Public Health, School of DentistryObjectives The influence of toothbrushing duration and dentifrice quantity on fluoride efficacy against dental caries is poorly understood. This study investigated effects of these two oral hygiene factors on enamel remineralisation (measured as surface microhardness recovery [SMHR]), enamel fluoride uptake (EFU), and net acid resistance (NAR) post-remineralisation in a randomized clinical study using an in situ caries model. Methods Subjects (n = 63) wore their partial dentures holding partially demineralised human enamel specimens and brushed twice-daily for two weeks, following each of five regimens: brushing for 120 or 45 s with 1.5 g of 1150 ppm F (as NaF) dentifrice; for 120 or 45 s with 0.5 g of this dentifrice; and for 120 s with 1.5 g of 250 ppm F (NaF) dentifrice. Results Comparing brushing for 120 s against brushing for 45 s, SMHR and EFU increased by 20.0% and 26.9% respectively when 1.5 g dentifrice was used; and by 22.8% and 19.9% respectively when 0.5 g dentifrice was used. Comparing brushing with 1.5 g against brushing with 0.5 g dentifrice, SMHR and EFU increased by 35.3% and 51.3% respectively when brushing for 120 s, and by 38.4% and 43.0% respectively when brushing for 45 s. Increasing brushing duration and dentifrice quantity also increased the NAR value. The effects of these two oral hygiene factors on SMHR, EFU, and NAR were statistically significant (p < 0.05 in all cases). Conclusion Brushing duration and dentifrice quantity have the potential to influence the anti-caries effectiveness of fluoride dentifrices. Study NCT01563172 on ClinicalTrials.gov. Clinical significance The effect of two key oral hygiene regimen factors – toothbrushing duration and dentifrice quantity – on fluoride’s anticaries effectiveness is unclear. This 2-week home-use in situ remineralisation clinical study showed both these factors can influence fluoride bioactivity, and so can potentially affect fluoride’s ability to protect against caries.Item Effects of casein phosphopeptide-amorphous calcium phosphate crème on nicotine-induced Streptococcus mutans biofilm in vitro(Springer, 2020) Alawadhi, Naser B.; Lippert, Frank; Gregory, Richard L.; Biomedical Sciences and Comprehensive Care, School of DentistryObjectives The aim of this study was to test the effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) crème, or MI Paste™ (MIP), on nicotine-induced Streptococcus mutans biofilm. The experiment utilized S. mutans biofilm assays with varying concentrations of nicotine and MIP aqueous concentrate levels. First hand exposure to nicotine has been demonstrated to significantly increase S. mutans biofilm formation, while the active component, CPP-ACP, in MIP has been shown to reduce S. mutans biofilm formation. Materials and methods A 24-h culture of S. mutans UA159 in microtiter plates were treated with varying nicotine concentrations (0–32 mg/ml) in Tryptic Soy Broth supplemented with 1% sucrose (TSBS) with or without MIP aqueous concentrate. A spectrophotometer was used to determine total growth absorbance and planktonic growth. The microtiter plate wells were washed, fixed, and stained with crystal violet dye and the absorbance measured to determine biofilm formation. Results The presence of MIP aqueous concentrate inhibits nicotine-induced S. mutans biofilm formation at different concentrations of nicotine (0–32 mg/ml). Conclusion The results demonstrated nicotine-induced S. mutans biofilm formation is decreased in the presence of MIP. This provides further evidence about the cariostatic properties of CPP-ACP, the active soluble ingredient in the MIP, and reconfirms the harmful effects of nicotine. Clinical significance Smokers may gain dual benefits from the use of MIP, as a remineralization agent and as a cariostatic agent, by inhibiting nicotine-induced S. mutans biofilm formation.Item The Effects of Fluoride, Strontium, Theobromine and their Combinations on Caries Lesion Rehardening and Fluoridation(Elsevier, 2017-08) Lippert, Frank; Department of Cariology, Operative Dentistry and Dental Public Health, School of DentistryObjective The aim was to investigate the effects of fluoride, strontium, theobromine and their combinations on caries lesion rehardening and fluoridation (EFU) under pH cycling conditions. Design Human enamel specimens were demineralized at 37 °C for 24 h using a pH 5.0 solution containing 50 mM lactic acid and 0.2% Carbopol 907 which was 50% saturated with respect to hydroxyapatite. Lesions were assigned to nine treatment groups (n = 16) based on Knoop surface microhardness indentation length. Treatment aqueous solutions were: placebo, 11.9 mM sodium fluoride (F), 23.8 mM sodium fluoride (2 × F), 1.1 mM strontium chloride hexahydrate (Sr), 1.1 mM F theobromine, Sr + theobromine, F + Sr, F + theobromine, F + Sr + theobromine. Lesions were pH cycled for 5d (daily protocol: 3 × 1min-treatment; 2 × 60min-demineralization; 4 × 60 min & overnight-artificial saliva). Knoop indentation length was measured again and%surface microhardness recovery (%SMHr) calculated. EFU was determined using the acid-etch technique. Data were analysed using ANOVA. Results Model showed fluoride dose-response for both variables (2 × F > F > placebo). For%SMHr, F + Sr+/−theobromine resulted in more rehardening than F, however less than 2 × F. F + theobromine was similar to F. For EFU, F + Sr was inferior to F, F + theobromine and F + Sr + theobromine which were similar and inferior to 2 × F. In absence of fluoride, Sr, theobromine or Sr + theobromine were virtually indistinguishable from placebo and inferior to F. Conclusions It can be concluded that a) strontium aids rehardening but not EFU and only in presence of fluoride; b) theobromine does not appear to offer any anti-caries benefits in this model; c) there are no synergistic effects between strontium and theobromine in the presence or absence of fluoride.Item Enamel demineralization and remineralization under plaque fluid-like conditions – a QLF study(Karger, 2011) Lippert, Frank; Butler, A.; Lynch, R. J. M.; Department of Cariology, Operative Dentistry and Dental Public Health, School of DentistryThe present study investigated de- and remineralization in enamel lesions under plaque fluid (PF)-like conditions using quantitative light-induced fluorescence (QLF). Preformed lesions were exposed to partially saturated lactic acid solutions, varying in pH and fluoride concentration ([F]) based on a 5 × 3 factorial study design (0/0.1/0.5/1.5/4 ppm F; pH 4.9/5.2/5.5). Average fluorescence loss (ΔF) was monitored for 11 days. Subsequently, lesions were demineralized in a partially saturated acetic acid solution for two 24-hour periods. Data were analyzed using repeated measures analysis of covariance. Lesions exposed to PF at 4 ppm F and pH 5.5 showed not only the most remineralization (ΔΔF = 28.2 ± 14.0%) for all groups after 11 days, but also the most demineralization (ΔΔF = –19.3 ± 13.5%) after subsequent acetic acid exposure. Increased [F] resulted in more remineralization, regardless of pH. Higher pH values resulted in more remineralization. No remineralization was observed in lesions exposed to F-free solutions, regardless of pH. Remineralization was noticeable under the following conditions: pH 4.9 – [F] = 4 ppm, pH 5.2 – [F] ≧ 1.5 ppm, and pH 5.5 – [F] ≧ 0.5 ppm. Overall, [F] had a stronger effect on remineralization than pH. Subsequent demineralization showed that little protection was offered by PF-like solutions, and further demineralization compared with baseline was observed on lesions not remineralized initially. [F] had a stronger effect on net mineral change than pH. The present study has shown that QLF is a valuable tool in studying lesion de- and remineralization under PF-like conditions, where [F] was shown to be more important than pH.Item Enhancing predicted fluoride varnish efficacy and post-treatment compliance by means of calcium-containing gummy bears(Elsevier, 2018) Lippert, Frank; Al Dehailan, Laila; Castiblanco, Gina A.; Tagelsir, Azza; Buckley, Christine; Eckert, George J.; Cariology, Operative Dentistry and Dental Public Health, School of DentistryObjectives This study determined whether consumption of calcium-containing gummies prior to fluoride varnish application enhances plaque fluoride retention and compliance with post-varnish application instructions. Methods The present study followed a multi-center, parallel, randomized, and laboratory analyst-blind design. Following IRB approval, parent consent and child assent, 44 subjects (7–12 years), were randomized to either gummy or no-gummy study groups. A baseline plaque sample was obtained after a wash-out period. Fluoride varnish (5% NaF) was applied; subjects in the gummy group received two calcium-containing gummies prior to varnish application. Subjects were given two questionnaires to complete (subject and parent) to investigate adherence to post-treatment instructions. Three days later, a second plaque sample was obtained. Plaque was analyzed for plaque fluid and solid fluoride concentrations. Fluoride data were analyzed using Wilcoxon Rank Sum tests, questionnaire data using Pearson chi-square tests. Results Plaque fluid fluoride did not change pre- to post-treatment in the gummy group (mean ± sd: 8.8 ± 5.7 μmol/l vs. 10.0 ± 6.3 μmol/l; p = 0.265) or in the no-gummy group (8.1 ± 4.4 μmol/l vs. 16.1 ± 20.0 μmol/l; p = 0.058). Groups were not different for plaque fluid fluoride pre-treatment (p = 1.000), post-treatment (p = 0.904), or change (p = 0.904). Plaque solid fluoride did not change pre- to post-treatment in the gummy group (0.89 ± 1.10 μmol/g vs. 1.37 ± 1.77 μmol/g; p = 0.073) or in the no-gummy group (0.68 ± 0.77 μmol/g vs. 2.01 ± 5.00 μmol/g; p = 0.190). Groups were not different for plaque solid fluoride pre-treatment (p = 1.000), post-treatment (p = 0.466), or change (p = 0.874). No significant differences were found between groups for questionnaire responses. Conclusion This study failed to demonstrate an effect of calcium-containing gummies in enhancing plaque fluoride retention.Item Exploratory randomized clinical trial of an experimental gel-to-foam fluoride dentifrice formulation using an in situ caries model(2015) Barlow, Ashley; Butler, Andrew; Mason, Stephen; Zero, Domenick; Department of Cariology, Operative Dentistry, and Dental Public Health, IU School of DentistryOBJECTIVE: To evaluate the in situ caries performance and safety of two experimental fluoride dentifrice formulations (1450 ppm fluoride) with and without 2% isopentane as an excipient, in comparison to a positive control, currently marketed dentifrice (1450 ppm fluoride) and a negative control dentifrice (0 ppm fluoride). METHODS: This was a single-center, examiner-blind, randomized, controlled, four-treatment cross-over study. During each treatment period, the subject wore a modified mandibular partial denture fitted with two gauze-covered, partially demineralized human enamel specimens, and brushed at home for one timed minute, twice daily, for two weeks. At the end of each treatment period, the enamel specimens were removed from the dentures for analysis. During the week between treatment periods, subjects returned to their usual dental hygiene practices for four to five days, received a dental prophylaxis, and used a study-designated non-fluoride dentifrice for two to three days before starting the next treatment. Treatment effect on enamel specimen remineralization was assessed by surface microhardness (SMH). Enamel fluoride uptake was assessed using microdrill enamel biopsy. RESULTS: All fluoride-containing dentifrices demonstrated significant, superior SMH recovery and levels of fluoride uptake compared to the negative control dentifrice. No significant differences were observed for either efficacy variable between the experimental dentifrice formulations and the positive control dentifrice. No significant difference was observed between the 2% isopentane dentifrice and the 0% isopentane dentifrice for SMH recovery. CONCLUSION: The addition of 2% isopentane did not positively or negatively affect fluoride efficacy in this model.Item Fluoride in the diet of 2-years-old children(Wiley, 2017-06) Martinez-Mier, E. Angeles; Spencer, Kathryn L.; Sanders, Brian J.; Jones, James E.; Soto-Rojas, Armando E.; Tomlin, Angela M.; Vinson, LaQuia A.; Weddell, James A.; Eckert, George J.; Cariology, Operative Dentistry and Dental Public Health, School of DentistryObjectives This study aimed to calculate the fluoride concentrations of commonly consumed foods and beverages for 2-years-old children utilizing market basket information for the US Midwest region. Methods Total Diet Study food lists were cross-referenced with National Health and Nutrition Examination Survey—What We Eat in America data to determine the foods and beverages to be included. Fluoride concentrations were determined using a modification of the hexamethyldisiloxane microdiffusion technique. Fluoride concentrations were summarized for each of the food categories. Daily dietary fluoride intake was estimated using a simulation analysis. Results Food and beverage fluoride concentrations varied widely, ranging from nondetectable for some oils and dairy products to more than 3.0 μgF/g food for some processed meats, fish and fruits. The estimated mean (±SD) daily dietary fluoride intake, excluding dentifrice and supplements, was 412±114 μgF/d. The estimated average ingestion for a 2-years-old weighing 12.24 kg was 0.034±0.009 mg/kg/d. A diet based on foods and beverages in the fifth percentile of fluoride intake distribution for an average child would result in 247 μgF/d or 0.020 mg/kg/d, while a diet with foods and beverages in the 95th percentile would result in a total intake of 622 μgF/d or 0.051 mg/kg/d. Conclusions The fluoride concentrations of foods and beverages vary widely, and, if items in the 95th percentile of fluoride intake distribution are ingested, children could consume more fluoride than the recommended 0.05 mg/kg/d. Fluoride intake calculated in this study was higher than historically reported dietary levels.