Characteristics of tin-containing fluoride toothpastes related to erosive tooth wear protection.

OBJECTIVES: To assess the effect of different tin-containing toothpastes on the control of erosive tooth wear in enamel and dentin. METHODS: Enamel and dentin slabs were randomly distributed into 7 experimental groups (n = 10/substrate): C-: negative control (Artificial saliva); AmF (regular fluoridated toothpaste without tin); Sn-1 (SnF2/NaF); Sn-2 (SnF2/NaF/SnCl2); Sn-3 (SnCl2/NaF); Sn-4 (SnF2/SnCl2); Sn-5 (SnCl2/AmF/NaF/chitosan). Specimens were submitted to 5-day erosion-abrasion cycling. Surface loss (SL) was determined with an optical profilometer. Tin deposition on the tooth surfaces and some characteristics of the toothpastes (pH, potentially available F-, %weight of solid particles, and RDA) were also assessed. Data were statistically analyzed (α = 0.05). RESULTS: For enamel, the Sn-2 presented the lowest SL, not differing significantly from AmF, C+, and Sn-3. The SL of these groups was significantly lower than the C-, except for Sn-3. Sn-1 and Sn-4 were also not significantly different from C-. For dentin, C- significantly showed the highest SL values, whilst, Sn-1 presented the lowest SL, not differing significantly from AmF, Sn-2, C+, and Sn-3. There was a significant positive association between enamel SL and the pH and tin deposition. Dentin SL was significantly negatively associated with the %weight of solid particles and RDA. CONCLUSIONS: Most of the tin-toothpastes were able to exhibit some protection against ETW. In this process, the toothpastes characteristics play a role, as lower enamel SL was significantly associated with lower pH values and tin deposition; and lower dentin SL was associated with higher %weight of solid particles and RDA of the toothpastes. CLINICAL SIGNIFICANCE: Tin-containing toothpastes can be used for erosive tooth wear protection, but our study showed that their effect depends on the pH, amount of tin deposition, % weight of solid particles and RDA of the toohpastes.

The effect of location/site on polished human enamel after mechanical and chemical wear.

OBJECTIVE: To compare profilometry and microhardness of polished occlusal and buccal human enamel following a mechanical and chemical wear regime. METHODS: Enamel from polished human molars were sectioned into buccal and occlusal surfaces and randomly allocated into two groups (n = 10) and then exposed to 0.3 % citric acid at pH 2.7 for 10, 20, 40 and 60 mins each followed by abrasion with non-fluoridated toothpaste for 240 strokes in a reciprocating brushing machine. A white light profilometer with a spot size of 12 um measured mean step-height following each cycle. Microhardness indentations were conducted following the final cycled 60 mins erosion/abrasion using 0.01, 0.02, 0.1, 0.5 and 2.5 kgf indentation load. Statistical disparity were evaluated using a two-way ANOVA and post-hoc Sidak's multiple comparisons tests at α = 0.05. RESULTS: After erosion/abrasion, the mean (SD) step-heights on occlusal and buccal surfaces were not significantly different until 60 mins, when occlusal surfaces exhibited greater step-heights, 32.9 µm (2.8) and 31.1 µm (1.8) and p = 0.02, respectively. Buccal and occlusal microhardness was statistically lower following erosion/abrasion at loads of 0.01 kgf (p = 0.0005) and 0.02 kgf (p = 0.0006) but no significant differences were observed in the microhardness between the surfaces at any loads. CONCLUSION: The occlusal and buccal surfaces were not statistically different for microhardness or step height suggesting the susceptibility to wear is not related to the anatomy and structure of the tooth and is more likely related to other factors such as the environment. CLINICAL SIGNIFICANCE: The study emphasizes that a notable difference in wear between occlusal and buccal enamel surfaces emerges only after prolonged exposure to simultaneous chemical and mechanical stress. This finding necessitates a preventive dental approach that accounts for both the duration of exposure and environmental factors.

Supplementation of Energy Drinks with Green Tea Extract: Effect on In Vitro Abrasive/Erosive Dentin Wear.

PURPOSE: To investigate the effect of the supplementation of energy drinks with green tea extract on abrasive and erosive dentin wear. MATERIALS AND METHODS: Six groups, each comprising 15 bovine dentin samples, were prepared, yielding a total of 90 samples. Erosion was performed by immersing the samples in Red Bull and Red Bull light with and without green tea extract. Tap water with and without green tea extract was used as the control groups. The samples were subjected to abrasive/erosive cycling for five days. The following cycling was performed daily: toothbrush abrasion (20 brushstrokes; 2.5 N); eight erosive cycles (2 min storage in the respective solutions); in between the erosive cycles, storage in artificial saliva (60 min) and again toothbrush abrasion (20 brushstrokes; 2.5 N). During the night, samples were again stored in artificial saliva. Abrasive/erosive dentin wear was measured using a stylus profilometer (µm, accuracy = 40 nm). The measured dentin loss results from the vertical position shift on the y-axis from base to final profile after the wear process in 2D. Pairwise comparisons between the groups were carried out using Wilcoxon signed-rank test. RESULTS: The following dentin wear (median [IQR]) was measured: Red Bull: 1.9 µm (0.5); Red Bull Light: 1.3 µm (0.3); Red Bull with green tea extract: 0.8 µm (0.3); Red Bull Light with green tea extract: 0.3 µm (0.5); Tap water with green tea extract: -0.2 µm (0.7); Tap water: -1.0 µm (1.2). The comparison of all tested groups to each other proved to be statistically significant (p < 0.05). CONCLUSION: The supplementation of energy drinks with green tea extract provide a protective effect against erosive/abrasive wear in vitro.

Interaction between Hexametaphosphate, Other Active Ingredients of Toothpastes, and Erosion-Abrasion in Enamel in vitro.

Sodium hexametaphosphate (HMP) as toothpaste additive is claimed to reduce erosive tooth wear and to stabilize stannous ions. However, little is known about the impact of concentration and its interactions with fluoride (F) or stannous+fluoride ions (F/Sn) on enamel erosion and erosion-abrasion. In a 10 day cyclic in vitro erosion-abrasion model, 320 flat human enamel specimens were divided into ten groups (n = 32 each) and daily subjected to six erosive challenges (0.5% citric acid, 2 min) and two toothpaste suspension applications (2 min, 1:3 F-free toothpaste:mineral-salt solution, 0.23% sodium gluconate). Half of specimens per group were additionally brushed twice/day (200 g, 15 s) during suspension immersion. Nine suspensions contained HMP (0.25%, 1.75%, 3.25%), either on its own or combined with F (373 ppm F-) or F/Sn (800 ppm Sn2+, 373 ppm F-). One suspension contained sodium gluconate only (NegContr). After 10 days, specimens' surfaces were analysed with profilometry, energy dispersive X-ray spectroscopy, and scanning electron microscopy. Tissue loss (µm, mean ± standard deviation) in NegContr was 10.9 ± 2.0 (erosion), 22.2 ± 1.6 (erosion-abrasion). Under erosive conditions, only 0.25% HMP in any combination and 1.75% HMP with F/Sn reduced loss significantly (-28% to -54%); 3.25% HMP without F and F/Sn increased loss significantly (+35%). With additional abrasion, no suspension reduced loss significantly compared to NegContr, instead, in groups without F and F/Sn or with 3.25% HMP loss was increased (+15% to +30%). Conclusively, at higher concentrations, HMP increased erosive tooth wear and seemed to reduce anti-erosive effects of fluoride and stannous ions.

Epidemiology, aetiology and prevention of tooth wear.

Tooth wear is a commonly reported finding globally; however, many patients are unaware of having tooth wear. Identifying early signs of erosion, abrasion or attrition and determining the risk factors contributing to a patient's tooth wear may help to prevent further loss of enamel and dentine in the future. Appropriate prevention should be instigated, or appropriate referral made to other health professionals, when conditions such as gastroesophageal reflux or eating disorders are suspected. This paper presents the epidemiology and aetiological factors for tooth wear, as well as identifying the common clinical presentations of tooth wear. Patient perspectives on tooth wear and preventive techniques that can be utilised are also discussed.

Effect of fluoride group on dental erosion associated or not with abrasion in human enamel: A systematic review with network metanalysis.

OBJECTIVES: This systematic review evaluated the efficacy of monovalent and polyvalent fluoride group compared to the non-fluoride group on the prevention of enamel erosion associated or not with abrasion in in situ studies. DESIGN: This review was registered in the PROSPERO (CRD42017071118) and followed PRISMA 2020 guidelines. A systematic and comprehensive search was performed using PUBMED, WEB OF SCIENCE, SCOPUS, EMBASE, BBO, LILACS, SCIELO, and grey literature IBICT-BDTD. All in situ and ex vivo studies of erosion and erosion/abrasion tooth wear were included, with no language or date restrictions. RESULTS: 730 studies were obtained and after exclusion of duplicates, 311 were included for title and abstract reading. Two independent authors (kappa= 0.98) systematically conducted the selection phase. Considering the eligibility criteria and after full-text reading, 19 studies were included in qualitative and quantitative analysis. CONCLUSION: Network metanalysis showed that polyvalent fluoride group, especially Sn-compounded, prevented enamel wear by erosion and erosion/abrasion compared to the non-fluoride group and monovalent fluoride group. Both low and high concentration monovalent fluoride group were not able to prevent erosion wear associated or not with abrasion. Sensitivity analysis of the network metanalysis was performed with the low risk of bias studies and the results were confirmed. There is robust evidence that stannous-compounded fluoridated and titanium tetrafluoride agents are effective in preventing erosion and erosion/abrasion compared to the non-fluoride group and other interventions.

Preventive effect of chitosan gel containing CaneCPI-5 against enamel erosive wear in situ.

OBJECTIVE: This study evaluated the preventive effect of a chitosan gel containing CaneCPI-5 against enamel erosion and erosion + abrasion in situ. METHODS: Sixteen volunteers participated in a crossover, double-blind protocol, comprising 4 phases: (1) no treatment (Nt); (2) chitosan gel (Cg); (3) chitosan gel + 12,300 ppm NaF (Cg + NaF); and (4) chitosan gel + 0.1 mg/mL CaneCPI-5 (Cg + Cane). Volunteers wore an appliance containing 4 specimens. Once/day, they applied the gel (except for Nt) (4 min/specimen). Erosive challenges were performed extra-orally (0.1% citric acid, 90 s, 4 × /day; ERO). Specimens were also abraded (toothbrush, 15 s/specimen, 2 × /day; ERO + ABR). Enamel wear was assessed by profilometry and relative surface reflection intensity (%SRI). Two-way RM-ANOVA/Sidak's tests and Spearman's correlation were used (p < 0.05). RESULTS: For profilometry, ERO + ABR promoted significantly greater wear when compared with ERO. There was a significant difference among all treatments. The lowest enamel loss occurred for Cg + Cane, followed by Cg + NaF, Cg, and Nt (p < 0.05). The %SRI was significantly lower for ERO + ABR when compared to ERO, only for the Nt group. The greatest %SRI was found for the Cg + NaF and Cg + Cane groups, which did not differ significantly, regardless of the conditions. The lowest %SRI was found for the Nt and Cg groups, which did not differ from each other, regardless of the conditions. The Nt group did not differ significantly from the Cg + NaF (ERO). There was a significant correlation between both analyses. CONCLUSION: The incorporation of CaneCPI-5 in the chitosan gel prevented erosive wear in situ. CLINICAL RELEVANCE: These results open a new perspective for the use of CaneCPI-5 in other application vehicles, such as chitosan gel.

REGULAR APPLICATION OF FLUORIDES TO TEETH IS LIKELY TO PROVIDE SOME PROTECTION AGAINST ENAMEL EROSION AND ABRASION.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Zanatta RF, TMF Caneppele, T Scaramucci, R El Dib, LC Maia, DM Ferreira, AB Borges Protective effect of fluorides on erosion and erosion/abrasion in enamel: a systematic review and meta-analysis of randomized in situ trials. Arch Oral Biol. 2020 Dec;120:104945. doi: 10.1016/j.archoralbio.2020.104945. Epub 2020 Oct 16. SOURCE OF FUNDING: Sao Paulo Research Foundation (grant number 2017/13799-8), National Council for Scientific and Technological Development, (grant numbers 310953/2015-4 and 310320/ 2017-8). TYPE OF STUDY/DESIGN: Systematic review with meta-analysis.

Effect of the toothbrush tuft arrangement and bristle stiffness on the abrasive dentin wear.

The geometrical properties of toothbrushes play a role in developing abrasive tooth wear and non-carious cervical lesions. This study investigated the interplay between the toothbrush tuft arrangement (crossed vs. parallel) and bristle stiffness (soft vs. medium) on the abrasive dentin wear using three slurries with different levels of abrasivity (RDA: 67, 121 and 174). Twelve groups of bovine dentin samples (n = 20) were brushed with a combination of the aforementioned variables. Abrasive dentin wear was recorded with a profilometer and the resulting abrasive wear of each group was calculated and compared with each other using two-way ANOVA and pairwise tests. Toothbrushes with parallel tuft arrangement caused statistically significantly higher dentin wear compared to crossed tuft arrangement, regardless of the abrasivity level of the used slurry and the bristle stiffness. Soft crossed tuft toothbrushes caused statistically significantly higher abrasive dentin wear than medium crossed tuft toothbrushes, while soft and medium parallel tuft toothbrushes caused the same amounts of dentin wear, regardless of the RDA value of the used slurry. These results could be helpful for dentists and dental hygienists when advising patients. Crossed tuft toothbrushes could be a less-abrasive choice in comparison to parallel tuft toothbrushes.

The effect of mouthwashes on fluoride dentifrices in preventing dental abrasion or erosion.

Erosive tooth wear (ETW) refers to the chemical dissolution of mineralized tissues by acids of non-bacterial origin. It occurs in the primary as well as the permanent dentition. In this study, our objectives were to investigate and compare the impact of chlorhexidine gluconate (CHX), essential oils (EO), and cetylpyridinium chloride (CPC) on ETW protection produced by conventional fluoride kinds of toothpaste. A clinically relevant in-vitro erosion/abrasion pH cycling model was employed to test the effect of the aforementioned mouthwashes on modulating the ability of NaF and SnF2 types of toothpaste. The mean dentin surface loss associated with NaF toothpaste was significantly lower than for the SnF2 toothpaste. On the other hand, enamel surface loss with SnF2 toothpaste was significantly lower than for the NaF toothpaste. Also, the surface loss of erosion was significantly higher when associated with abrasion than without brushing and for both enamel and dentin. There was no significant difference in the surface loss among all types of mouthwash. Commonly used types of mouthwash containing antimicrobial agents or additional fluoride do not impact fluoride toothpaste action on erosion/abrasion. Also, considering erosion only, the tested SnF2 dentifrice provided better protection against surface loss of enamel than the other.

Hesperidin reduces dentin wear after erosion and erosion/abrasion cycling in vitro.

OBJECTIVE: To evaluate the action of hesperidin (HPN) at different concentrations to prevent dentin erosive wear, associated or not to abrasion. METHODS: A study with 6 experimental groups (n = 10) for erosion (experiment 1) and another 6 for erosion + abrasion (experiment 2). The treatments were: distilled water (DW), DW with collagenase (DW + Col), 0.46% epigallocatechin-3-gallate (EGCG) and 0.1%, 0.5% or 1% HPN. The specimens were submitted to a cycle (3x/day) for 5 days that consisted of immersion on 1% citric acid (5 min), artificial saliva (60 min), treatment (5 min), brushing (150 movements only in experiment 2), and artificial saliva (60 min / overnight). Collagenase was added in artificial saliva for all groups except DW-group. Dentin changes were assessed with optical profilometry and scanning electron microscopy. Data were submitted to one-way analysis of variance and Tukey tests (α = 0.05). RESULTS: For experiment 1, DW showed the lowest wear and did not significantly differ from EGCG. DW + Col showed the highest wear, being significantly different from HPN at 1%. In experiment 2, DW showed the lowest wear and DW + Col the highest. EGCG showed less wear than the three groups treated with HPN. In addition, for both cycling models, there were no significant differences among the three concentrations of HPN analyzed. In micrographs of HPN-treated groups, it could be observed the formation of a barrier on the dentin that promoted the obliteration of the tubules. CONCLUSIONS: HPN was able to preserve the demineralized organic matrix layer but did not overcome the effect of EGCG.

Impact of mucin on the anti-erosive/anti-abrasive efficacy of chitosan and/or F/Sn in enamel in vitro.

The application of stannous ions in combination with fluoride (F/Sn) is one of the central strategies in reducing erosive tooth wear. F/Sn efficacy can be enhanced by adding chitosan, a positively charged biopolymer. For patients with low saliva flow, this efficacy, however, is not sufficient, making further improvement desirable. This could be achieved by combining chitosan with other molecules like mucin, which together might form multilayers. This in-vitro study aimed to investigate the effect of chitosan, mucin, F/Sn and combinations thereof on enamel erosion and erosion-abrasion. Human enamel samples (n = 448, 28 groups) were cyclically eroded or eroded-abraded (10 days; 6 × 2 min erosion and 2 × 15 s/200 g abrasion per day). Samples were treated 2 × 2 min/day with solutions containing either, chitosan (50 or 500 mPas), porcine gastric mucin, F/Sn or combinations thereof after abrasive challenge. Tissue loss was measured profilometrically, interaction between hard tissue and active agents was assessed with energy dispersive spectroscopy and scanning electron microscopy. Chitosan and F/Sn showed the expected effect in reducing tissue loss under erosive and under erosive-abrasive conditions. Neither mucin alone nor the combinations with mucin showed any additional beneficial effect.

Interplay between different manual toothbrushes and brushing loads on erosive tooth wear.

OBJECTIVE: To investigate the effect of different types of manual toothbrushes and brushing loads on the progression of erosive tooth wear (ETW) on enamel. METHODS: Bovine enamel specimens (n = 10) were submitted to a 5-day erosive-abrasive cycling model (0.3 % citric acid for 5 min, artificial saliva for 60 min, 4x/day). Toothbrushing was carried out 2x/day for 15 s, according to the toothbrushes tested (ultra-soft (a): Curaprox 5460; ultra-soft (b): Sensodyne Repair & Protect; soft (a): Colgate Slim Soft; soft (b): Oral-B Indicator Plus; medium: Johnson's Professional; hard: Tek) and brushing loads (1.5 N, 3 N). Surface loss (SL, in µm) was assessed by optical profilometry on conclusion of the cycling. Some of the toothbrush characteristics were evaluated. Data were statistically analyzed (α = 0.05). RESULTS: For the 1.5 N load, the hard brush showed the highest SL value, with statistical significance. The other toothbrushes did not differ significantly, except that ultra-soft (a) caused significantly higher SL than ultra-soft (b). For the 3 N load, hard and soft (a) exhibited the highest SL. Soft (b) and medium had the lowest SL value, with statistical significance. Only soft (a) and ultra-soft (b) showed significant difference between loads, with lower SL for the load of 1.5 N. None of the toothbrush characteristics were significantly correlated with SL. CONCLUSIONS: Although different degrees of enamel surface loss were observed with use of the different toothbrushes, no association was found between the toothbrush characteristics and SL. Depending on the toothbrush, the force of brushing was capable of modulating the ETW of enamel. Based on the brushing loads usually applied by healthy individuals, hard brushes are not recommended for use by patients with ETW. CLINICAL SIGNIFICANCE: The use of hard bristle brushes is not recommended for use by individuals who exert healthy forces when brushing their teeth. The toothbrush characteristics are of secondary importance in terms of causing enamel loss in ETW.

In vitro effect of children's toothpaste on brushing abrasion of eroded primary enamel.

PURPOSE: Emerging data have suggested that acid erosion has become an increasing clinical problem in pediatric dentistry. This study aimed to investigate the abrasive effects of two commercial toothpastes on primary enamel eroded by orange juice using an in vitro model. METHODS: Thirty enamel slabs were obtained from primary teeth and then randomly assigned to three groups (n = 8) comprising two different toothpastes: G1-control-distilled water; G2-Dentifrice A (containing no fluoride); and G3-Dentifrice B (1.100 ppmF-NaF). Each slab had one half protected to provide a control side, and the other one was subjected to treatments. The slabs were submitted to daily erosive challenges (3×/day, 2 min) in concentrated orange juice (pH 3.38) associated with abrasive challenges using a tooth-brushing machine (150 brush movements for each cycle). During the experimental period, the slabs were kept in 37 °C artificial saliva, and the experiment was carried out for 5 days. The depths of the resulting eroded areas were measured by stylus profilometry. The data were analyzed using ANOVA and the Tukey-Kramer test (α = 5%). RESULTS: Tooth loss (µm, mean ± SD) was 2.46 ± 1.18 for G1, 3.32 ± 2.12 for G2 and 2.14 ± 1.03 for G3. Therefore, the NaF dentifrice (Dentifrice B) produced significantly less mineral loss (p = 0.04) than dentifrice A. CONCLUSIONS: The findings suggest that fluoride toothpaste could protect primary enamel against erosion.

The Addition of Propylene Glycol Alginate to a Fluoride Solution to Control Enamel Wear: An in situ Study.

The aim of this study was to evaluate the protective effect of propylene glycol alginate (PGA) associated with sodium fluoride (NaF) against enamel erosion and erosion-abrasion. A 4-phase, split-mouth, double-blind, crossover in situ trial was conducted with the following solutions: F + PGA (225 ppm F- + 0.1% PGA), F (225 ppm F-), F + Sn (225 ppm F- + SnCl2, 800 ppm Sn2+), and negative control (distilled water). In each phase, 12 subjects wore removable mandibular appliances containing 4 enamel specimens, which were submitted either to erosion or to erosion-abrasion challenges for 5 days. Acquired salivary pellicle was formed in situ for 2 h. Erosion-abrasion consisted of acid challenge (1% citric acid solution, pH 2.3, 5 min, 4×/day), exposure to saliva in situ (2 h, 4×/day), brushing (5 s, total 2 min exposure to the slurry), and treatment with the solutions (2 min, 2×/day). For erosion, the same procedures were performed, without brushing. At the end, surface loss (SL; in µm) was evaluated by means of optical profilometry. KOH-soluble fluoride was quantified for erosion-only groups using extra specimens. For both challenges, the SL values found for F + PGA did not differ significantly from those of F and the negative control, and the SL value shown for F + Sn was significantly the lowest. Erosion-abrasion promoted significantly higher SL values than erosion. KOH-soluble fluoride analysis showed that F + Sn had a higher fluoride concentration in comparison with the negative control and F, while F + PGA did not differ from any of the other groups. In conclusion, PGA was not able to improve the protective effect of NaF against erosive enamel wear.

Does delayed toothbrushing after the consumption of erosive foodstuffs or beverages decrease erosive tooth wear? A systematic review and meta-analysis.

OBJECTIVE: Controversy exists regarding the effectiveness of delayed toothbrushing in decreasing erosive tooth wear (ETW). The purpose of this systematic review and meta-analysis was to assess the effects of delayed toothbrushing on ETW. MATERIALS AND METHODS: This systematic review and meta-analysis was conducted according to the PRISMA statement and registered in PROSPERO (CRD42020200463). PubMed, Embase, and Web of Science databases were systematically searched with no publication year limits. Screening and data extraction were performed independently by two reviewers. In situ and in vitro studies comparing ETW after delayed and immediate toothbrushing following an erosive attack were included. Review Manager software 5.3 (The Cochrane Collaboration, Oxford, UK) was used for statistical analyses. Heterogeneity was assessed with the Cochran Q test and I2 statistics. RESULTS: Of the 565 potentially relevant studies, 26 full-text articles were assessed for eligibility. Twelve articles were included in the systematic review, and 11 were included in the qualitative analyses. No significant difference in the ETW of human enamel was observed between delayed and immediate toothbrushing (P = 0.13), whereas significantly less ETW of bovine enamel was observed after delayed toothbrushing (P < 0.001). No significant difference in the ETW of bovine dentin was observed between delayed and immediate toothbrushing (P = 0.34). Studies on human dentin were not available. Subgroup analyses revealed a significant contribution of the use of fluoridated toothpaste to decreasing the ETW of human enamel after erosion and toothbrush abrasion (P = 0.02). CONCLUSIONS: Bovine and human teeth behaved differently in response to erosion and toothbrush abrasion. Delayed toothbrushing after an erosive attack was not effective at decreasing the ETW of human enamel compared to immediate toothbrushing, whereas it was effective at decreasing the ETW of bovine enamel. CLINICAL RELEVANCE: Delayed toothbrushing alone after the consumption of erosive foodstuffs or beverages is not capable of preventing erosive enamel wear.

Protective effect of fluorides on erosion and erosion/abrasion in enamel: a systematic review and meta-analysis of randomized in situ trials.

OBJECTIVES: To evaluate the effects of different fluoride types and vehicles when compared to water or placebo, on prevention of enamel erosion and erosive tooth wear progression. DESIGN: A systematic review followed by meta-analysis of randomized in situ trials was conducted. PubMeb, Scopus, Web of Science, LILACS, BBO, Scielo, EMBASE and CENTRAL electronic databases were searched. Studies with fluoride compounds (NaF, AmF, Sn, TiF4) and vehicles (toothpaste, mouth rinse, gel, and varnishes) compared to control (water or placebo) for control of enamel loss progression were included. Reviewers independently screened potentially eligible articles, extracted data, and assessed risk of bias. GRADE approach was used to rate the overall certainty of evidence for toothpastes and rinses under erosive/abrasive challenges. RESULTS: Thirty-two studies were elegible. Under erosive/abrasive challenges, enamel loss was significantly lower than control for NaF toothpastes [Mean difference(MD) -1.14; Confidence Interval(CI) -1.89 to -0.40] and Sn/associations [-6.02; -11.09 to -0.95], while no difference was found for AmF [-13.59; -39.7 to -12.52]. For mouth rinses, Sn/associations solutions were effective [-11.49; -16.62 to -6.37], but NaF showed no significant effect [-2.83; -8.04 to 2.38]. CONCLUSION: Overall, fluoride products are able to reduce enamel loss when compared to control, but results must be interpreted with caution. For toothpastes, NaF provided limited protection, with moderate evidence, while Sn/associations exhibited protective effect with low certainty of evidence. For rinses, NaF was not effective, with very low evidence, while the stannnous enriched fluorides offered higher protection regarding enamel erosion and erosive wear, with moderate certainty of evidence.

Pellicle Modification with Casein and Mucin Does Not Affect Surface Loss from Erosion and Abrasion.

AIM: A combination of the proteins casein and mucin is known to modify the salivary pellicle and improve its protection of the underlying enamel from erosion. It is so far not known if this protection is confined solely to erosion, or if it also extends to abrasion, and this in vitro study aimed at investigating this question. METHODS: A total of 72 human enamel specimens were prepared and randomly assigned to four groups: pellicle (P), casein/mucin (CM), pellicle + casein/mucin (PCM), and control (Ctrl). Each specimen underwent five cycles, each cycle consisting of a pellicle/treatment part, an erosion part (3 min in 1% citric acid, pH 3.6, 25°C, 70 rpm), and an abrasion part (50 toothbrush strokes within 25 s in toothpaste slurry with a 200-g load). The pellicle/treatment part consisted of 2 h of incubation in whole human saliva for group P, 2 h of incubation (25°C, 70 rpm) in a protein mixture of 1% casein and 0.27% mucin for group CM, and 2 h of incubation in saliva followed by 2 h of incubation in the protein mixture for group PCM. The fourth group (Ctrl) served as the control and was kept in a humid chamber without saliva or protein treatment. The enamel surfaces were scanned with an optical profilometer initially and after the final cycle, and surface loss was analyzed. Furthermore, the surface microhardness (SMH) was measured initially, after each pellicle/treatment part and each erosion cycle, and after the final abrasion cycle. The results were analyzed with Kruskal-Wallis and Wilcoxon tests with Bonferroni corrections. RESULTS: The different treatments did not show differences in surface loss and therefore did not protect enamel from surface loss by abrasion. Nonetheless, we observed differences in the SMH values, namely the Ctrl group being significantly softer than the experimental groups. CONCLUSION: The observed differences in SMH suggest that a different abrasion protocol could lead to differences in surface loss, and further investigation of whether and under which conditions pellicle modification leads to increased resistance to abrasion remains worthwhile.

Anti-erosive effect of rinsing before or after toothbrushing with a Fluoride/Stannous Ions solution: an in situ investigation: Application order of Fluoride/Tin products for erosive tooth wear.

OBJECTIVE: To evaluate the impact of the application of a F-/Sn2+-containing mouthrinse before or after toothbrushing with a F-/Sn2+/chitosan toothpaste on the progression of erosion/abrasion on enamel and dentin. METHODS: This crossover in situ study had five arms: Control (toothbrushing without toothpaste), Brushing (toothbrushing with toothpaste), Brushing + Rinsing, Rinsing + Brushing, and Rinsing (without toothbrushing). Fifteen subjects used removable mandibular appliances containing 3 enamel and 3 dentin specimens, which were subjected to erosion-abrasion cycling of 60 min salivary pellicle formation followed by 5 min extra-oral erosion with 1% citric acid (4x/day for 5 days). Treatments were performed in situ after first and last erosive challenges with rinse (10 ml; 30 s) and/or toothbrushing with/without toothpaste (with electric toothbrush; 5 s per specimen; total 2 min contact with slurry). Surface loss (SL) was evaluated with an optical profilometer. Data were analyzed by two-way repeated measures ANOVA and Tukey tests (α = 0.05). RESULTS: The Control showed the highest SL (mean ±â€¯SD for enamel: 24.58 ±â€¯11.32; dentin: 32.32 ±â€¯10.10; all µm). Rinsing alone resulted in significantly lower SL value (enamel: 8.30 ±â€¯4.96; dentin: 16.15 ±â€¯8.29) compared with arms that applied toothpaste, except Brushing + Rinsing. None of the arms that underwent toothbrushing with the toothpaste differed from each other (p > 0.05). Dentin specimens showed significantly higher SL values than enamel (p < 0.001). CONCLUSION: The order of treatment applications had no influence on their anti-erosive effect; however, toothbrushing with F-/Sn2+/chitosan toothpaste reduced enamel surface loss. Additional rinsing with F-/Sn2+ mouthrinse did not offer improved protection. CLINICAL SIGNIFICANCE: The use of fluoride- and stannous- containing toothpastes and mouthrinses is an important approach in the prevention of erosive tooth wear. Further evidence is needed to support the benefit of combining these products against this condition.

Toothpaste factors related to dentine tubule occlusion and dentine protection against erosion and abrasion.

OBJECTIVES: To investigate the effect of toothpastes on dentine surface loss and tubule occlusion, and the association of toothpaste-related factors to each of the outcomes. MATERIALS AND METHODS: One hundred and sixty human dentine specimens were randomly distributed into 10 groups, according to different toothpastes. The specimens were submitted to artificial saliva (60 min), citric acid (3 min), and brushing abrasion (25 s; totalizing 2 min in toothpaste slurries). This was repeated five times and two outcome variables were analyzed: dentine surface loss (dSL; µm) and tubule occlusion by measurement of the total area of open tubules (Area-OT; µm2). Data were analyzed with Kruskal-Wallis and Mann-Whitney tests (α = 0.05); bivariate and multivariate regressions were used to model the association of the chemical (pH, concentration of F-, Ca2+, and PO43- and presence of Sn2+) and physical (% weight of solid particles, particle size, and wettability) factors of the toothpastes to both outcome variables. RESULTS: Toothpastes caused different degrees of dSL and did not differ in Area-OT. All chemical and physical factors, except the presence of Sn2+, were associated with dSL (p < 0.001). Area-OT was associated only with the presence of Sn2+ (p = 0.033). CONCLUSION: Greater dSL was associated with lower pH, lower concentration of F-, higher concentration of Ca2+ and PO43-, greater % weight of solid particles, smaller particle size, and lesser wettability, whereas tubule occlusion was associated with the presence of Sn2+. CLINICAL RELEVANCE: Depending on their chemical and physical composition, toothpastes will cause different degrees of dentine tubule occlusion and dentine surface loss. This could, in turn, modulate dentine hypersensitivity.