Haroula Koletsi-Kounari

Effect of fluoride and of calcium sodium phosphosilicate toothpastes on pre-softened dentin demineralization and remineralization in vitro.

OBJECTIVES The purpose of this in vitro study was to evaluate the effect of toothpastes containing sodium fluoride in different concentrations or a calcium sodium phosphosilicate system on pre-softened dentin demineralization and remineralization. METHODS During a ten day pH-cycling protocol, pre-softened bovine root dentin slabs were immersed twice daily, after the demineralization periods, for 2min, in the following toothpaste slurries: (a) non-fluoridated (control), (b) 7.5% calcium sodium phosphosilicate, (c) 1450 ppm F, (d) 2800 ppm F and (e) 5000 ppm F. Subsequently, the specimens were subjected to a 15-h acid resistance test. Surface microhardness was assessed initially and during the pH-cycling and the acid resistance test period. Repeated measurements in each group were analyzed through appropriate regression models for longitudinal data. RESULTS All fluoride groups, during pH cycling, showed significantly less microhardness loss (p < or = 0.010, p < or = 0.002, p < or = 0.002) and subsequently exhibited increased acid resistance (p < or = 0.010, p < or = 0.001, p < or = 0.001) compared to the control. The 5000 ppm and 2800 ppm F toothpastes, inhibited demineralization significantly more effectively than the 1450 ppm F (p < or = 0.001, p < or = 0.030) and the calcium sodium phosphosilicate toothpaste (p < or = 0.001), while no significant differences were found between the two high fluoride groups (p=0.130). The calcium sodium phosphosilicate toothpaste, during pH cycling showed a difference that approached statistical significance compared to control (p=0.079), but its acid resistance behavior was similar to control (p=0.610). CONCLUSIONS Under these experimental conditions, the high fluoride toothpastes promoted remineralization and inhibited demineralization more effectively, than the 1450 ppm F, the non-fluoridated (control) and the calcium sodium phosphosilicate toothpastes.

Prevalence of dental caries in 5‐year‐old Greek children and the use of dental services: evaluation of socioeconomic, behavioural factors and living conditions

OBJECTIVES To assess dental caries and use of dental services experience in 5-year-old children attending public kindergartens in Attica, Greece and to examine the influence of certain socioeconomic factors and living conditions as well as dental behaviours and attitudes. METHODS In this cross-sectional study, a random and stratified sample of 605 Greek children was examined using decayed, missing, filled tooth surfaces and simplified debris indices. The use of dental services was measured by childrens dental visits (any dental visit up to the age of 5 years). Care Index was also calculated. Risk indicators were assessed by a questionnaire. Zero-inflated Poisson and Logistic Regression Analysis were generated to test statistical significant associations. RESULTS The prevalence of dental caries was 16.5%. Care Index was 32% and dental visits were reported for the 84% of the children. Medium Socio-Economic Level (SEL) was associated with no detectable caries. High SEL was related to decreased decayed, missing, filled teeth values, while female gender and rented houses had the opposite effect. The age of the mother (35-39 years) and the higher SEL were related to higher levels of dental services use. CONCLUSIONS It is suggested that there are differences in the experience of dental caries and use of dental services among preschool children in Attica, which are related to demographic, socioeconomic factors and living conditions. Dental public polices should focus on groups with specific characteristics in order to improve oral health levels of disease-susceptible populations.

Novel methods of balancing covariates for the assessment of dental erosion: A contribution to validation of a synthetic scoring system for erosive wear

OBJECTIVES The purpose of the study was to balance several potential erosive covariates, using traditional and novel epidemiological approaches, in order to assess the relative risks of dental erosion more precisely. METHODS Traditional (univariate and logistic regression analysis) and novel techniques (propensity scores and Inverse Probability Weighting-IPW) were applied for evaluating the effect of twenty covariates on dental erosion among 502 adolescents. RESULTS Different approaches gave different estimates of the relative risks of dental erosion. The increased consumption of carbonated soft drinks had the major erosive effect, when traditional analyses were used (unadjusted: OR=3.475 and CI: 1.499-8.052, logistic regression: OR=3.219 and CI: 1.373-7.547). On the other hand, IPW method indicated that the consumption of erosion drinks immediately after intense physical exercise had the highest odds ratio (OR=1.363 and CI: 0.963-1.929), followed by the increased consumption of citrus fruit juice (OR=1.326 and CI: 1.004-1.752). This method also demonstrated a marked improvement in balance, with the 95% CIs for each OR being considerably narrower than those reported in the initial analysis. CONCLUSIONS Standardization of the potential aetiological criteria of erosive wear is a considerably difficult process. Nevertheless, novel methods revealed that the increased consumption of carbonated soft drinks and citrus fruit juices could be included as aetiologic factors in a synthetic scoring system for erosion. Parameters which are related to salivary protective mechanisms (e.g. consumption of erosion drinks immediately after intense physical exercise) could also be a part of such an index. Further research is required in order to achieve the maximum validation of the potential erosive risk factors.

Adhesion of Porphyromonas gingivalis and Biofilm Formation on Different Types of Orthodontic Brackets.

Objectives. To examine the interaction between Porphyromonas gingivalis and 3 different orthodontic brackets in vitro, focusing on the effect of an early salivary pellicle and other bacteria on the formation of biofilms. Material and Methods. Mono- and multi-species P. gingivalis biofilms were allowed to form in vitro, on 3 different bracket types (stainless steel, ceramic and plastic) with and without an early salivary pellicle. The brackets were anaerobically incubated for 3 days in Brain Heart Infusion Broth to form biofilms. Bacteria were quantified by trypsin treatment and enumeration of the total viable counts of bacteria recovered. Results. Saliva was found to significantly affect (P < 0.001) adhesion and biofilm formation of P. gingivalis, with higher numbers for the coated brackets. No significant effect was detected for the impact of the type of biofilm, although on stainless steel and plastic brackets there was a tendency for higher numbers of the pathogen in multi-species biofilms. Bracket material alone was not found to affect the number of bacteria. Conclusions. The salivary pellicle seems to facilitate the adhesion of P. gingivalis and biofilm formation on orthodontic brackets, while the material comprising the brackets does not significantly impact on the number of bacteria.

Gender differences in oral health status and behavior of Greek dental students: A meta-analysis of 1981, 2000, and 2010 data

Background: The aim of this study was to investigate the oral health status and behavior of Greek dental students over time, and to meta-analyze these findings to test the widely documented hypothesis that women have better oral health behavior, oral hygiene, and periodontal status but higher dental caries rates than men. Materials and Methods: A total sample of 385 students was examined using identical indices to assess oral health and behavioral data initially in 1981 while the years 2000 and 2010 were selected due to significant changes that took place in the dental curriculum in the 1990s and 2000s. Data by gender concerning the outcome variables recorded in every one of the three surveys were analyzed using Mantel—Haenszel and continuous outcomes methods. Results: A significant improvement in the oral health status and behavior of students was observed over time. The meta-analysis of data by gender showed that females brushed their teeth significantly more often than males [summary odds ratio (OR): 1.95 and 95% confidence interval (CI): 1.08—3.54]. Males and females were found to have a similar risk of developing dental caries. Conclusion: The hypothesis that young women have better oral hygiene habits compared to men was confirmed. However, the hypothesis that women have better oral hygiene and periodontal status but exhibit higher dental caries experience than men was not supported by the findings of the study.

Effect of toothpastes containing different NaF concentrations or a SnF2/NaF combination on root dentine erosive lesions, in vitro

Background Fluoride toothpastes presumably offer some protection against acid erosion. However, uncertainty exists towards fluoride’s efficacy relatively to the concentration and the type of chemical compound used. This in vitro study evaluated the relative efficacy of toothpastes containing sodium fluoride in different concentrations or a stabilized stannous fluoride/sodium fluoride system on root dentine erosion. Material and Methods Bovine dentin specimens were allocated into four groups (n=10): control (no F), 1450ppm F (as NaF), 5000ppm F (as NaF) and 1450ppm F (1100ppm as stabilized SnF2 and 350ppm as NaF)/sodium hexamethaphosphate. The specimens were submitted to 6 daily cycles of erosion (0.3% v/v citric acid, pH=3.2, 20 min) and remineralization (~22h), interspersed by 2-min immersions in 1:3 w/v of dentifrice/distilled water slurries. Subsequently, they were subjected to a 24-h acid resistance test (0.3% v/v citric acid, pH=3.2) without any further treatments. Surface loss was quantified by contact profilometry. Data were analysed through one-way ANOVA and Bonferroni’s tests (p≤0.05). Results In both experiments, all fluoride groups, showed significantly less tissue loss compared to the control (p<0.001-p=0.018). During erosion cycling, no significant differences were found among the fluoride groups. During the acid resistance test, the 5000ppm F toothpaste produced significantly superior effect than both 1450ppm F products (p=0.010, (p<0.001), which performed similarly. Conclusions Under less aggressive erosive conditions, fluoride toothpastes did not differ in their ability to protect dentine surfaces. However, in severely erosive environment, the 5000ppm F toothpaste performed superiorly to the other tested products. Key words:Dentine, sodium fluoride, stannous fluoride, tooth erosion, toothpaste, contact profilometry.