Kjersti Refsholt Stenhagen

Protective effect of TiF(4) solutions with different concentrations and pH on development of erosion-like lesions.

Aim: To evaluate how concentration and pH of TiF4 influence the erosion-protective effect. Methods: Specimens were treated with a TiF4 solution: (1) 0.5 M F, pH 1.2, (2) 0.05 M F, pH 2.1, (3) 0.5 M F, pH 2.1, or (4) 0.05 M F, pH 1.2; then, they were exposed to HCl. Results: After 2 min, the proportions of the area covered with the coating were 93, 71, 17 and 0% in groups 1–4. When present, the coating seemed to protect the surface. After 6 min, a coating could only be seen in group 1 (43%). Conclusion: Reducing the concentration of TiF4 and increasing the pH of the solution decreased the protective effect.

The Effect of Daily Fluoride Mouth Rinsing on Enamel Erosive/Abrasive Wear in situ

It is not known whether application of fluoride agents on enamel results in lasting resistance to erosive/abrasive wear. We investigated if one daily mouth rinse with sodium fluoride (NaF), stannous fluoride (SnF2) or titanium tetrafluoride (TiF4) solutions protected enamel against erosive/abrasive wear in situ (a paired, randomised and blind study). Sixteen molars were cut into 4 specimens, each with one amalgam filling (measurement reference surface). Two teeth (2 × 4 specimens) were mounted bilaterally (buccal aspects) on acrylic mandibular appliances and worn for 9 days by 8 volunteers. Every morning, the specimens were brushed manually with water (30 s) extra-orally. Then fluoride solutions (0.4% SnF2 pH 2.5; 0.15% TiF4 pH 2.1; 0.2% NaF pH 6.5, all 0.05 m F) were applied (2 min). Three of the specimens from each tooth got different treatment, and the fourth served as control. At midday, the specimens were etched for 2 min in 300 ml fresh 0.01 m hydrochloric acid and rinsed in tap water. This etch procedure was repeated in the afternoon. Topographic measurements were performed by a white-light interferometer. Mean surface loss (±SD) for 16 teeth after 9 days was: SnF2 1.8 ± 1.9 µm, TiF4 3.1 ± 4.8 µm, NaF 26.3 ± 4.7 µm, control 32.3 ± 4.4 µm. Daily rinse with SnF2, TiF4 and NaF resulted in 94, 90 and 18% reduction in enamel erosive/abrasive wear, respectively, compared with control (p < 0.05). The superior protective effect of daily rinse with either stannous or titanium tetrafluoride solutions on erosive/abrasive enamel wear is promising.

Comparing Different Methods to Assess Erosive Lesion Depths and Progression in vitro

The aim of this study was to compare the precision and accuracy of 5 different methods applied to assess surface substance loss or changes in surface microhardness (SMH) on the same enamel surfaces after repeated acid exposures. Ground specimens from human molars were exposed to 0.01 M HCl (pH 2.2) for 6 min × 2 and measurements performed 3 times to estimate precision. The accuracies (systematic errors) were calculated against the manufacturer’s calibration standard. Lesion depth progression was from 94 to 110%, related to repeated acid exposure. The precisions/accuracies were: WLI (white light interferometry), 0.5/0.4%; SP (stylus profilometry), 4.7/0.7%; OP (optical profilometry), 1.4/12%; AAS (atomic absorption spectroscopy), 0.4/17% (measured calcium loss was converted to lesion depth). The correlation between WLI and SP was R2 = 0.98, and between WLI and OP it was R2 = 0.85. SMH gave information on qualitative changes of the surface (precision: 5.5%, accuracy: 4.0%). WLI performed best in precision and accuracy, but SP, OP and AAS are all relevant methods for analysing lesion depths and progression, SMH seems suitable for analysing minor changes in surface enamel only.

The Susceptibility to Dental Erosion Differs among Individuals.

Studies of wine tasters and patients with self-induced vomiting have revealed that 30-50% of individuals at high risk do not develop erosive lesions. The aim was to investigate this apparent individual susceptibility to enamel erosion. Two enamel specimens were made from each of 3 premolars from 8 persons (donors). Six acrylic mouth appliances were worn by 6 volunteers (carriers). One specimen from each donor was mounted on each appliance. The carriers wore the appliances for 9 days. The appliances were immersed in 0.01 M HCl for 3 min twice per day to imitate a vomiting/reflux situation. The enamel specimens were analysed by a white-light interferometer to measure enamel loss (in micrometres). The enamel loss varied significantly both between the donor teeth (p = 0.009) and the carriers (p = 0.004). The lesion in the specimen with the largest amount of enamel loss was 4 times as deep as in the specimen with the lowest. In 1 carrier, all specimens displayed enamel loss above the mean, including the specimen from the donor with the most resistant enamel. The variation in susceptibility to erosion among individuals appears to be influenced both by the sustainability of the enamel and by factors in the oral environment. This could explain the variation in prevalence and severity of dental erosions among patients exposed to similar acidic challenges. The results suggest that for certain individuals, only minimal acidic challenges may be sufficient to cause damage to the teeth, while others may never develop dental erosions despite extensive exposure to acid.

May caries-preventive fluoride regimes have an effect on dental erosive wear? An in situ study.

Abstract Objective. High and low concentration NaF regimes have shown caries protective properties, but the preventive effect against erosive/abrasive wear is unclear. Aim. To measure the inhibiting effect on enamel wear of low and highly concentrated sodium fluoride (NaF) toothpastes and a stannous (SnF2) fluoride gel in a single-blind, randomized in situ study, using a White Light Interferometer. Materials and methods. Sixteen human molars were each divided into four specimens, mounted on acrylic mouth appliances and worn by eight volunteers for 9 days. Experimental procedures were performed in the laboratory. The enamel specimens were brushed every day with fluoride-free toothpaste. Treatments; group 1: no fluoride treatment (control), group 2: SnF2 gel 2500 ppm F (5 min) every third day, group 3: NaF toothpaste 5000 ppm F 5 min every third day and 2 min the other days, group 4: NaF toothpaste 1450 ppm F (2 min) every day. In order to mimic gastric reflux/vomiting, the specimens were etched with 0.01 M HCl for 2 min twice a day. Results. The mean step height (µm) for the control specimens was −32.9 (SD = 6.8). The mean values for the other groups were −22.2 (SD = 8.4) (group 2), −30.8 (SD = 7.8) (group 3) and −31.4 (SD = 7.7) (group 4). Compared with the control, the SnF2 treated specimens showed significantly lower wear. The NaF toothpastes gave no significant protective effect. Conclusions. Application of SnF2 gel every third day gave protection against erosive–abrasive challenges. Daily application of both low concentration and high concentration NaF toothpaste provided no protection.

Enamel erosion depths measured on impressions by a white light interferometer

Abstract Objective. To investigate if measurements of the step heights on an impression of eroded enamel surfaces may give reliable values of the etching depths measured directly on the enamel. Materials and methods. Twelve human enamel specimens, with one circular amalgam reference surface in each, were mounted on an epoxy block and ground flat. Baseline images were taken by a White Light Interferometer (WLI) followed by 12 min etch by 0.01 M HCl, pH 2.2. The mean etch depth on each specimen was calculated from three repeated measurements, both on the specimen surfaces and on the silicone polymer impressions of the surfaces. Paired samples t-test was used when comparing the precision of measurements on enamel vs on impression. Results. The mean lesion depths after 12 min etch measured on the 12 enamel surfaces and impressions were 9.9 µm and 10.6 µm, respectively. The direct and indirect measurements correlated well (r 2 = 0.95), with 7% higher mean etch depth measured on the impressions (p < 0.05). The reliability of three repeated measurements on enamel and impressions expressed by Intra Class Correlation (ICC) were 0.98 and 0.99, respectively. The average relative precisions of three repeated measurements on the 12 tooth and impression surfaces were (0.5 ± 0.1)% and (0.1 ± 0.02)%, respectively (p < 0.05). The accuracies were 0.4% and 7%, respectively. Conclusion. WLI gave reliable but slightly higher etch depth measurements on impressions compared to enamel surfaces.

The effect of single-application fluoride treatment on simulated gastric erosion and erosion-abrasion of enamel in vitro.

PURPOSE To compare single-application fluoride formulations on enamel erosion and erosion-abrasion in vitro. MATERIALS AND METHODS Enamel specimens were pretreated with either sodium, tin, titanium, or sodium/calcium fluoride and subjected to either an erosion model or an erosion-abrasion model, after which optical profilometry was used to measure enamel step height loss. RESULTS For erosion, the titanium fluoride (P < .001) reduced enamel loss, whereas the calcium, tin, and sodium treatments showed no significant effects (P > .05). For erosion-abrasion, the titanium fluoride increased enamel loss in comparison to control (P < .001). CONCLUSIONS Titanium fluoride has differing effects on enamel loss from erosion and erosion-abrasion models.

New animal model of extrinsic dental erosion-Erosive effect on the mouse molar teeth

OBJECTIVE Consumption of acidic food and drinks is considered as important risk factor for development of dental erosion. There are several in vitro and in situ studies focusing on the risk indicators and preventive treatment, however, the need for a standardized animal model has been emphasised for many years. The aim was to establish an animal model of extrinsic dental erosion, which may serve as a standard for future studies to improve our understanding of the erosion. DESIGN Two acidic drinks, sports drink and cola drink, were given to young mice for six weeks. Experimental and control (water) molars and incisors were dissected out and observed by scanning electron microscopy (SEM). Mandibular first molars were subsequently ground transversely and observed again by SEM. The tooth height and enamel thickness were measured on the SEM images. RESULTS The lingual surface of the mandibular molars was most eroded after consumption of acidic drinks. The cola drink exhibited higher erosive effect on mandibular molars compared to sports drink. The lingual tooth height, compared to control, was about 34% and 18% lower in the cola drink and sports drink molars, respectively. Compared to the control molars, the lingual enamel was about 23% thinner in the sports drink molars and totally eroded on the certain lingual areas of the cola drink molars. CONCLUSIONS This new animal model of extrinsic dental erosion and the presented method with ground molars observed in SEM are suitable for further studies, which will gain deeper insights into the erosive disease.

Dental Erosive Wear Risk Assessment

This chapter presents a newly developed dental erosive wear risk assessment tool designed for use by general dental practitioners, dental educators, and dental students. The tool guides the user through the most common risk factors associated with dental erosive wear, and when combined with the Basic Erosive Wear Examination (BEWE) or other similar scoring system, leads to a final decision on patient risk status. An initial screening section helps the dentist to decide whether it is necessary to perform a more comprehensive dental erosive wear risk assessment. When there is clearly a need for further assessment, all dental erosive wear lesions are then recorded using the index of choice, and the dentist decides how the recorded conditions will be documented. The dentist then uses the Dental erosive wear risk assessment (DEWRA) form, where dietary and oral hygiene habits, general health status, and clinical conditions are evaluated using a thorough patient interview. An overall patient risk category is chosen and the section for treatment planning and advice to the patient can then be used. The last part of this chapter provides a brief explanation of the various risk factors that are included in the DEWRA form.