Maintaining strong healthy teeth for life is important; therefore the present study was concerned with the recognition of the significance of exploring some of the preventive and therapeutic products on the surface loss of enamel slabs subjected to acidic erosion and tooth brushing abrasion challenges using in vitro and in situ experiments.
Study 1 In vitro assessment of the effect of fluoridated toothpastes on bovine and human enamel subjected to acidic erosion and tooth brushing abrasion.
Aims: To assess the anti-erosive potential of toothpastes containing different delivery fluoride systems using bovine dental enamel (Part Ι) and human enamel (Part ІΙ) subjected to both acidic erosion and tooth brushing abrasion.
Part Ι: Methods: Fifty bovine enamel slabs were mounted in acrylic blocks, ground flat, tested for flatness by scanning profilometry (Proscan 2000, Scantron, UK), standardised for hardness using a Knoop hardness tester (under 100 g load for 15 s) and divided into five experimental groups (E1-E5) including 10 specimens per group. The tested toothpastes were : E1 Meridol® group, (AmF/SnF2; 0.14%), E2 Elmex® anti-caries group (AmF; 0.14%F), E3 Pronamel®, (NaF, 1450 ppm F), E4 Elmex® sensitive plus (AmF; 0.14%F), and E5 Aronal® 0 ppm F. De/remineralisation cycling procedures were achieved with immersion of the slabs under static conditions in aliquots of citric acid (0.3%, pH 3.6) for 2 mins followed by soaking for 1hr in artificial saliva between the erosive challenges. The erosive challenges procedures were repeated 5 times daily for 28 days. All groups were subjected twice a day to brushing abrasion during application of a slurry of toothpaste/saliva (1: 3) with 15 tooth brushing strokes using a 300 g load and incubated overnight at 37 ˚C in night time saliva at the end of the last brushing of the enamel slabs. Erosion and abrasion depths (µm) were quantified using profilometry scanning (Proscan 2000, Scantron, UK) at 7, 14, 21 and 28 days. Part ΙΙ: Similar erosive / abrasive experimental procedures were used on human enamel specimens. Results: After 28 days of erosion cycling with tooth brushing abrasion, all groups showed different enamel surface loss (µm). One-way ANOVA, demonstrated that E1 showed similar trends with E5, whereas (E2, E3, E4 showed significantly less surface loss (p<0.05) compared to E1 and E2. Conclusions: The effect of dental erosion and tooth brushing abrasion combined can be decreased by toothpastes containing amine fluoride and sodium fluoride, whereas no protection was observed with the stannous and amine fluoride paste. Similar result trends were observed for both bovine and human enamel specimens under this erosive/abrasive model.
Study 2 The effect of therapeutic products in combination on prevention of tooth surface loss.
Aims: To study combined topical fluoridated measures on erosive and abrasive enamel wear in vitro. Methods: Sixty bovine enamel specimens were divided into four groups containing (15 samples per group) were subjected to cyclic de /remineralisation procedures. Demineralisation was performed with 0.3% citric acid (pH 3.6) 2 min / five times per day. The enamel slabs were immersed in day artificial saliva between each erosive challenge for 1 hour and incubated overnight in night saliva at 37 oC. Two times daily fluoride application with toothpaste and artificial saliva slurry (1:3 ratio) plus a tested mouthrinse with automated tooth brushing (15 strokes, 300 g load) for (2x2 min/ day) during the experimental process. The test product treatments were: group 1 Elmex® sensitive plus toothpaste (AmF, 1400 ppm F) Plus Elmex® erosion mouthrinse containing (500 ppm F as AmF/NaF and 800 ppm Sn as SnCl2) stannous chloride rinse (Elmex TP plus MR) 2 times / day; group 2 Pronamel® toothpaste (NaF, 1450 ppm F+ 5%KNO3) + Pronamel® (NaF) mouthrinse (Pronamel® TP plus MR) 2 mins x2 times / day; group 3 Pronamel® toothpaste (NaF, 1450 ppm F) 2 / day plus GC tooth mousse™ once/ a day for 5 mins (Pronamel® TP plus TM) after the last brushing; group 4 (0 ppm F toothpaste) as a control. Enamel loss was determined by scanning profilometry after the last experimental days at 7, 14, 21, and 28 days. Results: after 28 days significantly less enamel surface loss (µm) was observed with group1: (Elmex TP plus MR) (0.40±0.23) and group 2: (Pronamel TP plus MR) (0.60±0.28)(Pronamel TP plus TM) had (2.65±1.79) (p<0.01) compared to 0 ppm F control (1.84±1.85). Conclusions: The topical applications of preventive therapeutic measures in the form of AmF, 1400 ppm F toothpaste plus Elmex® erosion dental rinse (500 ppm F + 800 ppm Sn) or applications of NaF/5% KNO3 toothpaste plus NaF mouthrinse significantly decreased the effect of erosion and tooth brushing abrasion compared to combinations containing remineralising agent or fluoride-free toothpaste.
Study 3: Investigations of therapeutic products on prevention of enamel surface loss under erosive and abrasive challenges in situ
Aims: To investigate the effect of fluoridated toothpaste alone or in combination with mouth rinse on the prevention of tooth surface loss under acidic erosion and tooth brushing abrasion in situ. Methods: Seventeen healthy participants wore a small upper removable mouth appliance holding two sterilised bovine enamel slabs that were randomly assigned to investigate one of the five test products for 14 days entered a prospective controlled, double-blind, crossover with five phases trial. All participants that signed informed consents and fulfilled the inclusion criteria were enrolled in the study. The five treatment groups were: group A (Elmex® erosion protection toothpaste (1400 ppm F as AmF/NaF and 3500 Sn2); group B (non-fluoride® toothpaste as a control); group C (Sensodyne Pronamel® 1450 ppm F as NaF/5%KNO3 toothpaste); group D (.Sensodyne Pronamel® 1450 ppm F as NaF toothpaste plus Pronamel® mouth wash as 450 ppm F NaF) and group E (Elmex® erosion protection toothpaste (1400 ppm F as AmF/NaF and 3500 Sn2) with Elmex® erosion protection dental rinse as AmF and NaF 500 ppm F plus stannous chloride 800 stannous (Sn2). The enamel slabs were dipped extra-orally in 0.3% citric acid solution at predetermined times for 2 minutes/ five times daily. In addition the enamel slabs were brushed for 1min extra-orally then 1 min intra-orally using the standard toothpaste/natural saliva slurry and 10 ml mouthrinse was used for 60s twice per day (10 ml x2). Enamel loss was determined by surface profilometry (Proscan 2000, Scantron, UK). Results: Treatment with therapeutic products Elmex® erosion protection toothpaste, Sensodyne Pronamel® toothpaste, Sensodyne Pronamel® toothpaste plus Sensodyne Pronamel® mouthrinse and Elmex® protection erosion toothpaste and Elmex® erosion protection rinse demonstrated a highly statistically significant difference in reducing the erosive and abrasive enamel surface loss (p ≤ 0.001) compared to the control group (0 ppm F).
Conclusion: Elmex® erosion protection (1400 ppm F) toothpaste combined with Elmex® erosion protection mouthrinse gave the greatest outstanding benefit. Furthermore, using combined anti-erosive therapeutic products in the form of Sensodyne Pronamel® 1450 ppm F NaF toothpaste plus Pronamel® mouth wash 450 ppm F NaF; Elmex® erosion protection toothpaste (1400 ppm F as AmF).and Sensodyne Pronamel® 1450 ppm F as NaF toothpaste significantly reduced the daily effect of erosive/abrasive tooth wear and provided better enamel surface loss reduction compared to the non-fluoride® toothpaste.
