Potential of different fluoride gels to prevent erosive tooth wear caused by gastroesophageal reflux

Concentration of Fluoride in Saliva After Fluoride Gel Application: A Randomised Clinical Trial

OBJECTIVE

The aim of this randomised clinical trial (RCT) was to assess the concentration of fluoride ions in saliva after applying fluoride gel and to examine the extent to which rinsing the mouth with water affects the content of fluoride ions in saliva as opposed to no rinsing after brushing teeth with gel.

METHODS

This single-blind RCT was conducted amongst a group of students (N = 103) and consisted of a questionnaire, clinical examination, saliva collection, and laboratory analysis. After saliva samples were collected, the students brushed their teeth for 2 minutes with Elmex Gelée (Colgate-Palmolive). Next, saliva was collected after 15 and 60 minutes from Group A (spitting out saliva after brushing) and from Group B (spitting out and rinsing with water after brushing). Statistical analysis was performed using a t test to compare the means between the groups.

RESULTS

Fifteen minutes after brushing, the level of fluoride increased in Group A about 15-fold to 15.33 ± 14.73 ppm and in Group B about 6-fold to 6.19 ± 5.97 ppm (P < .001). After 60 minutes, in Group A it decreased to 1.68 ± 0.83 ppm and in Group B to 0.60 ± 0.37 ppm (P < .001).

CONCLUSIONS

The use of fluoride gel in the absence of mouth rinsing produced significantly higher level and a concentration of fluoride in saliva. A post-gel brushing without rinsing might be suitable for patients at high risk for caries. Hence fruther research on the effect of a mouth rinse after use of fluoride gels is eesential to confirm our findings, and to promulgate evidence-based recommendations.

Effect of silver diamine fluoride/potassium iodide treatment on the prevention of dental erosion in primary teeth: an in vitro study

INTRODUCTION

Dental erosion has a great effect on oral health, when diagnosed it is irreversible, this sets the importance of different preventive measures being investigated against dental erosion.

AIM

This in vitro study aims to evaluate the effectiveness of silver diamine fluoride and Potassium iodide (SDF-KI) in comparison to casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) varnish, sodium fluoride (NaF) varnish, silver diamine fluoride (SDF) alone and deionized water as a control group in the prevention of dental erosion in primary teeth and assessing its staining effect.

MATERIALS AND METHODS

Forty deciduous teeth enamel specimens were randomly allocated into the five study groups. Tested materials were applied. An erosive challenge was done by immersing the specimens in a citric acid-containing soft drink with pH 2.85, for 5 min, 4 times/day, for 5 days. Changes in surface microhardness, mineral loss, and color change were evaluated besides recording of the surface topography and surface roughness for selected specimens.

RESULTS

The highest decrease in surface microhardness was recorded in the control group (-85.21 ± 10.60%), with a statistically significant difference (p = 0.002). SDF-KI group (-61.49 ± 21.08%) showed no statistically significant difference when compared to CPP-ACPF, NaF, and SDF groups. For calcium and phosphorous loss, control group was statistically significantly higher compared to the treatment groups (p = 0.003) and (p < 0.001) respectively, while there was no statistically significant difference between the tested treatment groups. The highest mean value for color change was recorded in SDF group (26.26 ± 10.31), followed by SDF-KI group (21.22 ± 12.87) with no statistically significant difference between groups.

CONCLUSIONS

SDF-KI is as effective as CPP-ACPF, NaF varnishes and SDF in the prevention of dental erosion in primary teeth, there was no statistically significant difference regarding its staining potential.

Species-specific enamel differences in hardness and abrasion resistance between the permanent incisors of cattle (Bos primigenius taurus) and the ever-growing incisors of nutria (Myocastor coypus)

Hypselodont (ever-growing) teeth of lagomorphs or rodents have higher wear rates (of a magnitude of mm/week), with compensating growth rates, compared to the non-ever-growing teeth of ungulates (with a magnitude of mm/year). Whether this is due to a fundamental difference in enamel hardness has not been investigated so far. We prepared enamel samples (n = 120 per species) from incisors of cattle (Bos primigenius taurus) and nutria (Myocastor coypus, hypselodont incisors) taken at slaughterhouses, and submitted them to indentation hardness testing. Subsequently, samples were split into 4 groups per species (n = 24 per species and group) that were assessed for abrasion susceptibility by a standardized brush test with a control (no added abrasives) and three treatment groups (using fine silt at 4 ±1 μm particle size, volcanic ash at 96 ±9 μm, or fine sand at 166 ±15 μm as abrasives), in which enamel abrasion was quantified as height loss by before-and-after profilometry. The difference in enamel hardness between the species was highly significant, with nutria enamel achieving 78% of the hardness of cattle enamel. In the control and the fine sand group, no enamel height loss was evident, which was attributed to the in vitro system in the latter group, where the sand particles were brushed out of the test slurry by the brushes’ bristles. For fine silt and volcanic ash, nutria enamel significantly lost 3.65 and 3.52 times more height than cattle. These results suggest a relationship between enamel hardness and susceptibility to abrasion. However, neither the pattern within the species nor across the species indicated a monotonous relationship between hardness and height loss; rather, the difference was due to qualitative step related to species. Hence, additional factors not measured in this study must be responsible for the differences in the enamel’s susceptibility to abrasion. While the in vitro brush system cannot be used to rank abrasive test substances in terms of their abrasiveness, it can differentiate abrasion susceptibility in dental tissue of different animal species. The results caution against considering enamel wear as a similar process across mammals.

Appraisal of shallow groundwater quality with human health risk assessment in different seasons in rural areas of the Guanzhong Plain (China)

Groundwater is the major source of water for drinking and irrigation purposes in and around Hua County, Shaanxi Province, China. The main purposes of this research is to evaluate the groundwater quality in the rainy and dry seasons of Hua County and analyze the causes of seasonal differences and determine the areas with serious pollution. Groundwater quality was assessed in this study using entropy water quality index (EWQI) and some graphical approaches such as Gibbs and Piper diagrams. The contour maps of groundwater quality were drawn by Geographical Information System (GIS). According to the obtained results, the locations where groundwater quality was rated as excellent or good in both wet and dry seasons were mainly in the north and east of the research area. COD and NO₃^- are the parameters that have the most serious negative effect on water quality. The dominant factors influencing groundwater chemical evolution in the study area were rock weathering and dissolution, and the precipitation and evaporation during the wet and dry seasons do not cause significant changes in groundwater chemistry. Adults' health risks results revealed that 27.69% and 52.31% of the groundwater samples exceeded the acceptable limit for non-carcinogenic risk in the wet and dry season, respectively, while for children the ratios are 30.16% and 47.62%, respectively. The contributive percentages of nitrate, fluoride and nitrate to the total risk are 61.29%, 28.71% and 10.00% in the wet season and 68.84%, 20.85% and 10.31% in the dry season. The risk is higher in the south than in the north of the study area, and is especially high in the southwest of the study area.

Groundwater Quality and Associated Human Health Risk in a Typical Basin of the Eastern Chinese Loess Plateau

Groundwater is an important source for drinking, agricultural, and industrial purposes in the Linfen basin of the Eastern Chinese Loess Plateau (ECLP). To ensure the safety of drinking water, this study was carried out to assess the quality using the water quality index (WQI) and potential health risks of groundwater using the human health risk assessment model (HHRA). The WQI approach showed that 90% of the samples were suitable for drinking, and Pb, TH, F−, SO42−, and TDS were the most significant parameters affecting groundwater quality. The non-carcinogenic health risk results indicated that 20% and 80% of the samples surpassed the permissible limit for adult females and children. Additionally, all groundwater samples could present a carcinogenic health risk to males, females, and children. The pollution from F−, Pb, and Cr6+ was the most serious for non-carcinogenic health risk. Cd contributed more than Cr6+ and As to carcinogenic health risks. Residents living in the central of the study area faced higher health risks than humans in other areas. The research results can provide a decision-making basis for the scientific management of the regional groundwater environment and the protection of drinking water safety and public health.

Enamel Erosion Reduction through Coupled Sodium Fluoride and Laser Treatments before Exposition in an Acid Environment: An In Vitro Randomized Control SEM Morphometric Analysis

(1) Background: Erosive lesions of dental enamel are steadily increasing owing to both the availability of exogenous acid and the production of endogenous acid. The aim of this study was to investigate the erosion-inhibiting potential of a diode laser irradiation and topical application of fluoride used alone or in combination on the enamel surface of extracted teeth before exposure to an acidic solution. (2) Methods: The four axial enamel surfaces of 40 healthy molars were used for four study groups: (A) no treatment; (B) application of fluoride gel for 120 s; (O) a diode laser application for 120 s; and (X) a combined laser/fluoride for 120 s. Each enamel surface was examined by SEM (scanning electron microscopy). (3) Results: At 700× magnification, it was possible to detect the enamel prisms of the test area of groups A, B, and O, while no structures such as enamel prisms were highlighted for group X because they were covered by an amorphous layer. The mean number of prisms ×1000 µm2 was 7.2 units with an SD of 0.72 for group A, 8 units with an SD of 0.96 for group B, and 4.8 units with a SD of 0.4 for group O. Student’s t-test showed no significant difference between group A and B with a p = 0.054. Group O showed a significant reduction of prims ×1000 µm2 compared with group A (p = 0.0027) and group B (p = 0.0009). Student’s t-test showed no significant difference between groups A and B with a p = 0.054. Group O showed a significant reduction of prims density with respect to group A (p = 0.0027) and group B (p = 0.0009). (4) Conclusions: This amorphous layer might be correlated with the effect of laser on enamel, which reduces both water and carbonate ion; increases the crystallinity of hydroxyapatite, and improves the mechanical properties of enamel; which is responsible for greater protection expressed by the enamel of group X against acid attacks.

Oral Hygiene Practice among Hospitalized Patients: An Assessment by Dental Hygiene Students

AIM

An epidemiological study was carried out, in hospital wards, with the aim of assessing the oral health status of patients subjected to multiple medical treatments.

MATERIAL AND METHODS

The study was conducted at Fondazione IRCCS Policlinico San Matteo (Pavia, Italy). A questionnaire was submitted to patients for the evaluation of oral hygiene devices used; then, a clinical examination was conducted to collect Decayed Missing Filled Teeth (DMFT) index, Plaque Index (PI), and Marginal Gingival Index (MGI) values.

RESULTS

Manual toothbrushes were used by a wide range of the sample study (65-100% among hospital wards), together with mouthwash (20-80%); interproximal aids were used by few patients (the lowest recorded value was 33.3%).

CONCLUSION

dental hygienists could be integrated into hospital wards as oral hygiene procedure instructors, for the improvement of the oral health conditions of hospitalized patients.