Description of a new laboratory evaluation method of interdental brush abrasion as a clinical hazard.

OBJECTIVES: To simulate the abrasive potential of an interdental brush when applied with toothpastes and prophylactic gels/solutions in a novel laboratory brushing simulation set-up. METHODS: A brushing device was customized to treat dentin samples mimicking a simplified interdental space with an interdental brush (ISO 2). The brushing, that is, 7200 strokes for 1 h, was performed with artificial saliva (control), a povidone-iodine solution, and slurries of chlorhexidine and fluoride gels as well as three toothpastes with different RDA values ranging from 29 to 100, respectively. The loss of dentin was profilometrically assessed and compared with ANOVA and Fishers LSD. RESULTS: While artificial saliva as control, the solution and the gel slurries showed no measurable dentin loss, toothpastes resulted in a measurable linear surface damage with respect to the actual intrinsic RDA values and ranged from 12.6 to 26.5 µm (p < 0.001). CONCLUSIONS: Any interdental cleaning product should be tailored and carefully instructed. Any over- and misuse should be avoided, which applies especially to the use of interdental brushes in combination with abrasive toothpastes.

Polyphenols for Preventing Dental Erosion in Pre-clinical Studies with in situ Designs and Simulated Acid Attack.

Dental erosion is a chemical process characterized by acid dissolution of dental hard tissue, and its etiology is multifactorial. Dietary polyphenols can be a strategy for dental erosion management, collaborating to preserve dental tissues through resistance to biodegradation. This study describes a comprehensive review to interpret the effects of polyphenols on dental erosion of pre-clinical models with in situ designs and simulated acid attacks on enamel and dentin samples. We aim to evaluate evidence about Polyphenols' effects in the type of dental substrate, parameters of erosive cycling chosen in the in situ models, and the possible mechanisms involved. An evidence-based literature review was conducted using appropriate search strategies developed for main electronic databases (PubMed, Scopus, Web of Science, LILACS, EMBASE, LIVIVO, CINAHL, and DOSS) and gray literature (Google Scholar). The Joanna Briggs Institute checklist was used to evaluate the quality of the evidence. From a total of 1900 articles, 8 were selected for evidence synthesis, including 224 specimens treated with polyphenols and 224 control samples. Considering the studies included in this review, we could observe that polyphenols tend to promote a reduction in erosive and abrasive wear compared to control groups. However, as the few studies included have a high risk of bias with different methodologies and the estimated effect size is low, this conclusion should not be extrapolated to clinical reality.

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.

Shape, size, and quantity of ingested external abrasives influence dental microwear texture formation in guinea pigs.

Food processing wears down teeth, thus affecting tooth functionality and evolutionary success. Other than intrinsic silica phytoliths, extrinsic mineral dust/grit adhering to plants causes tooth wear in mammalian herbivores. Dental microwear texture analysis (DMTA) is widely applied to infer diet from microscopic dental wear traces. The relationship between external abrasives and dental microwear texture (DMT) formation remains elusive. Feeding experiments with sheep have shown negligible effects of dust-laden grass and browse, suggesting that intrinsic properties of plants are more important. Here, we explore the effect of clay- to sand-sized mineral abrasives (quartz, volcanic ash, loess, kaolin) on DMT in a controlled feeding experiment with guinea pigs. By adding 1, 4, 5, or 8% mineral abrasives to a pelleted base diet, we test for the effect of particle size, shape, and amount on DMT. Wear by fine-grained quartz (>5/<50 µm), loess, and kaolin is not significantly different from the abrasive-free control diet. Fine silt-sized quartz (∼5 µm) results in higher surface anisotropy and lower roughness (polishing effect). Coarse-grained volcanic ash leads to significantly higher complexity, while fine sands (130 to 166 µm) result in significantly higher roughness. Complexity and roughness values exceed those from feeding experiments with guinea pigs who received plants with different phytolith content. Our results highlight that large (>95-µm) external silicate abrasives lead to distinct microscopic wear with higher roughness and complexity than caused by mineral abrasive-free herbivorous diets. Hence, high loads of mineral dust and grit in natural diets might be identified by DMTA, also in the fossil record.

Dentin abrasion using whitening toothpaste with various hydrogen peroxide concentrations.

PURPOSE: To compare the amount of abrasion of four whitening toothpastes, two conventional toothpastes, and seven experimental toothpastes with varying concentrations of hydrogen peroxide. METHODS: Bovine dentin specimens were treated with the four whitening toothpastes (containing three different concentrations of hydrogen peroxide: 0.75%, 1.50%, and 2.80%), two conventional toothpastes without hydrogen peroxide, seven experimental toothpastes (concentrations of hydrogen peroxide: 0.75%, 1.50%, 3.0%, 4.50%, 6.0%, 7.50%, and 9.0%), and distilled water. After 10,000 strokes of toothbrushing, the amount of abrasion on the dentin surface was measured with a contactless 3D surface profiler (n= 8). The pH of all solutions, the weight percentages of the particles, and the component of particles in the toothpaste were analyzed. The correlations between the dentin abrasion, pH, and weight percentages of the particles in the toothpastes were investigated. RESULTS: The amount of abrasion of the two conventional toothpastes were 1.1-3.6 times higher than those of the four whitening toothpastes. Likewise, the pH of the conventional toothpaste was higher than those of the other whitening toothpastes. No significant differences were found among the four whitening toothpastes. The four whitening toothpastes consisted of a relatively lower weight percentage of particles compared to the two conventional toothpastes. A strong positive correlation was observed between the dentin abrasion and the weight percentages of the particles (r= 0.913; P< 0.05). Furthermore, no significant differences in the amount of abrasion were observed between the specimens treated with seven experimental toothpastes and those treated with distilled water. CLINICAL SIGNIFICANCE: The whitening toothpastes containing less than 9% hydrogen peroxide did not seem to harm the dentin surface significantly. These findings can serve as a reference for consumers, patients, and dental professionals.

Longterm abrasive and erosive effect of whitening toothpaste on dentin surface.

PURPOSE: To evaluate the amount of dentin loss following immersion in or toothbrushing with whitening toothpaste (WT) containing hydrogen peroxide (HP) and citric acid (CA). Additionally, the amount of dentin loss after brushing with a WT alone or in combination with a conventional toothpaste was assessed, and the effects of HP and CA solutions on the dentin surface were investigated. METHODS: Bovine dentin specimens (n= 350) were randomly assigned to seven solutions of various compositions as toothpaste: The specimens assigned to each solution were then further divided into five treatment groups (n=10 each) : Group A = 1-hour immersion in each solution (ES); Group B = 10,000 brushing in ES; Group C = 1-hour immersion in ES + 10,000 brushing in ES; Group D = 1-hour immersion in ES + 10,000 brushing in reference slurry (RS); Group E = 10,000 brushing in ES + 10,000 brushing in RS. The amount and pattern of dentin loss were determined, and the surfaces were observed using noncontact profilometry. RESULTS: The WT (pH 5.0) caused lower dentin loss than RS after a single brushing cycle; however, the extent of dentin loss after 1 hour of immersion in the WT was significantly greater than that in the RS. Among the specimens treated with WT, a significant difference in dentin loss was observed between Group C and Groups D and E (P< 0.05) but not between Groups D and E. The surfaces exposed to CAS1, CAPB, and WT exhibited U-shaped patterns of dentin loss after brushing or immersion, whereas a wedge-shaped pattern was observed in those that underwent brushing with the RS. CLINICAL SIGNIFICANCE: The effects (dentin abrasion) of a whitening toothpaste containing hydrogen peroxide and citric acid when used in combination with a conventional toothpaste were similar to those seen with the continuous use of a conventional toothpaste alone.

In Vitro Assessment of Different Toothbrush Designs on Enamel Surface Abrasion: A Profilometric Study.

AIM: The purpose of this study was to evaluate the impact of three different toothbrush designs on enamel surface abrasion. MATERIALS AND METHODS: Sixty intact freshly extracted maxillary central incisors were considered for the study. All of the extracted teeth's surfaces were severely trimmed, leaving only the labial surface intact. In the trial, a conventional teeth-whitening dentifrice slurry was utilized. A brushing model was created to deliver uniform force in unidirectional motion. Dontrix Gauge was used to control the tension of the spring. The force was kept constant at 180 ± 20 g. The mounted enamel samples were separated into three groups (20 samples each) at random: group A: toothbrushes have a flat trim bristle design, group B: toothbrushes have a zigzag pattern, and group C: toothbrushes have a bi-level bristle design. For 2 weeks, each sample was brushed twice daily for 2 minutes. A profilometer was used to measure the average surface roughness. RESULTS: After toothbrushing, the maximum mean surface roughness score was found in zigzag pattern group (2.10 ± 0.23), followed by bi-level bristle design group (2.06 ± 0.12) and the least was in the flat trim bristle design group (1.96 ± 0.09). There was a significant difference between the different toothbrush bristle pattern groups (p < 0.001). CONCLUSION: On conclusion, the results of this study showed that, in comparison to toothbrushes with zigzag patterns and bi-level bristle designs, flat trim toothbrush bristle designs cause the least amount of surface abrasion and are relatively safe to use. CLINICAL SIGNIFICANCE: Toothbrushing with toothpaste contributes significantly to dental abrasion. A variety of parameters, including toothpaste abrasivity and concentration, brushing frequency, brushing length, brushing force, and toothbrush bristle stiffness, have the potential to influence the abrasion process of dental hard tissue.

Effect of brushing force on the abrasive dentin wear using slurries with different abrasivity values.

OBJECTIVE: The aim of this study was to investigate the resulting abrasive dentin wear using abrasive slurries with different RDA values and applying increasing brushing forces. METHODS: Forty-five bovine incisors were randomly allocated in three groups (A, B, C, n = 15). One hundred and eighty dentin samples were prepared from these incisors and allocated to twelve groups (A1-A4, B1-B4, C1-C4; n = 15). The groups were subjected to a brushing cycle (120 strokes/min, 25 min) as follows: groups A1 to A4 with an abrasive slurry (RDA = 71) applying increasing brushing forces (1, 2, 3 and 4 N). Groups B1 to B4 were brushed using an abrasive slurry (RDA = 85) and C1 to C4 (RDA = 133) applying the same above-mentioned brushing forces. Abrasive dentin wear was recorded using a stylus profilometer and compared amongst the groups using robust models. Pairwise comparisons in each model were tested and corrected after Tukey's method (α = 0.05). RESULTS: Applying 1-N brushing force resulted in the same amount of abrasive dentin wear in all groups regardless of the abrasivity of the used slurry. Increasing the brushing force to 2 N resulted in statistically significantly higher abrasive wear in all groups. This increase in abrasive wear was much higher when the slurry with high abrasivity was used (RDA = 133) compared with the lower abrasive slurry (RDA = 71). CONCLUSION: The abrasivity of the used slurry does not add to the resulting abrasive wear when the brushing force is kept at 1 N. It seems better to advise and help the patients (showing signs of non-carious cervical lesions) calibrating their brushing force to 1 N, than only to advise them to use toothpastes with lower abrasivities.

Relative dentin and enamel abrasivity of charcoal toothpastes.

OBJECTIVES: Very little data are known about charcoal toothpastes. The aim of this study was to counteract the missing data by determining the relative dentin abrasivity (RDA) and relative enamel abrasivity (REA) values of charcoal toothpastes. METHODS: Radioactively charged dentin and enamel samples were randomly divided into groups of eight specimens. Each group was brushed with two of total 12 charcoal toothpaste slurries and with a standard abrasive with a known RDA and REA value. The measured radioactivity in counts per minute within the slurries corresponds to the amount of dentin or enamel abraded. RDA and REA values of the charcoal toothpastes were expressed relative to the known value of the standard slurry. RESULTS: The RDA and REA values of the charcoal toothpastes have a broad range of 24-166 and 0-14, respectively. CONCLUSIONS: The RDA and REA values do not differ significantly from previously tested commercially available toothpastes. However, the lack of fluoride compounds in many of the investigated charcoal toothpastes can have a less beneficial effect for the consumers. It is very important to educate patients accordingly.

[Aesthetic management of erosive tooth wear using injection molding technique]. / Esteticheskoe lechenie vertikal'noi stiraemosti zubov s ispol'zovaniem in"ektsionnoi tekhniki.

In this article, on the example of a clinical case, the technique of restoring two central teeth in a patient with increased enamel erasability with highly filled fluid composite materials using injection techniques is described. The application of this technique has become possible because the new fluid composites have similar mechanical, physical and aesthetic properties to universal composite materials.

A Brief History of Tooth Wear.

Historical publications that have significantly improved the understanding of tooth wear mechanisms are reviewed with a focus on descriptions of the lesions, the evolution of their classification systems, and considerations addressing the main risk factors. Surprisingly, most important advances are often the oldest. Likewise, they are currently only marginally known, which requires a major dissemination effort.

[Psychological and mental aspects of increased tooth abrasion]. / Psikhologicheskie i psikhicheskie aspekty povyshennoi stiraemosti zubov.

The analysis of literary and other information sources (in PubMed, Google Scholar, KiberLeninka and eLibrary databases) devoted to the study of dental manifestations of psychological conditions and the analysis of the ability of dentists to identify psychological predictors of increased tooth erasure in adolescents and young people. Disorders such as stress, depression, attention deficit hyperactivity disorder, alcohol dependence, eating disorders - may be risk factors for the development of increased tooth abrasion. Comorbid conditions such as bruxism and gastroesophageal reflux are also considered. Due to the high mortality of adolescents due to mental illness, early diagnosis of disorders of psychological and mental health of adolescents is extremely relevant. Attention is focused on the possibility of early diagnosis by dentists of psychological and mental problems by the presence and type of increased erasability of teeth. Effective examination and treatment of such patients requires a holistic, interdisciplinary approach.

Non-Biological and Biological Risk Indicators for Tooth Wear Outcomes in Adults.

This study was undertaken to estimate the prevalence and severity of tooth wear (TW), as well as to assess non-biological and biological risk indicators for TW outcomes in adults. A cross-sectional study, adhering to the reporting STROBE guidelines, was conducted and had a convenience sample of adults ≥18 years of age who had at least one bilateral posterior molar contact. A total of 570 participants, seeking consultation at the University Hospital in Brussels, Belgium, were allocated to three age groups: 18-34 years (n = 232), 35-54 years (n = 256), and ≥55 years old (n = 79). Participants answered a self-applied questionnaire regarding sociodemographics, oral hygiene, and lifestyle behavior. The questionnaire was tested-retested (intraclass correlation coefficient = 0.71). Inter-examiner reliability for clinical examinations was k = 0.76-0.80. The prevalence of TW was 75% (95% CI: 71.7-78.9). Out of these patients, 42% (95% CI: 38.0-46.3) had as the primary etiological factor the process of dental erosion, while 22% (95% CI: 18.9-25.9) and 11% (95% CI: 8.6-13.9) had the processes of dental attrition and dental abrasion, respectively. The severity of TW according to BEWE highest score was mild in 31%, moderate in 28%, and severe in 17% of participants. The hierarchical logistic regression model for the association between risk indicators and TW irrespective of the etiology was significant for age (>35-54 years: OR = 2.35 and ≥55 years: OR = 3.89; p < 0.001), gender (>male: OR = 2.03; p < 0.001), toothpaste (>sensitive teeth: OR = 2.34; p = 0.005), occlusal splint (>yes: OR = 1.62; p = 0.03), and acidic beverages (≥once per day: OR = 1.62; p = 0.044). Consumption of acidic beverages was not associated with TW having as the primary etiological factor the process of dental attrition or dental abrasion, while it was significantly associated with the process of dental erosion (>once per week: OR = 1.69; p = 0.043 and ≥once per day: OR = 1.73; p = 0.016). Medical conditions were equally associated with the latter (OR = 3.11; p < 0.001). These findings could contribute to improving the effectiveness and sustainability of awareness in contemporary adult populations. In conclusion, the prevalence and severity of TW in adults were substantial. Medical conditions and consumption of acidic beverages were risk indicators for TW having as the primary etiological factor the process of dental erosion, although associations were moderate and weak, respectively.

Forage silica and water content control dental surface texture in guinea pigs and provide implications for dietary reconstruction.

Recent studies have shown that phytoliths are softer than dental enamel but still act as abrasive agents. Thus, phytolith content should be reflected in dental wear. Because native phytoliths show lower indentation hardness than phytoliths extracted by dry ashing, we propose that the hydration state of plant tissue will also affect dental abrasion. To assess this, we performed a controlled feeding experiment with 36 adult guinea pigs, fed exclusively with three different natural forages: lucerne, timothy grass, and bamboo with distinct phytolith/silica contents (lucerne < grass < bamboo). Each forage was fed in fresh or dried state for 3 weeks. We then performed 3D surface texture analysis (3DST) on the upper fourth premolar. Generally, enamel surface roughness increased with higher forage phytolith/silica content. Additionally, fresh and dry grass feeders displayed differences in wear patterns, with those of fresh grass feeders being similar to fresh and dry lucerne (phytolith-poor) feeders, supporting previous reports that "fresh grass grazers" show less abrasion than unspecialized grazers. Our results demonstrate that not only phytolith content but also properties such as water content can significantly affect plant abrasiveness, even to such an extent that wear patterns characteristic for dietary traits (browser-grazer differences) become indistinguishable.

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.

Simulation of Non-Carious Cervical Lesions by Computational Toothbrush Model: A Novel Three-Dimensional Discrete Element Method.

Non-carious cervical lesions (NCCLs) are saucer-shaped abrasions of a tooth. NCCLs can form due to various etiologies, including toothbrushing wear, acid erosion, and mechanical stress. Owing to this complex interplay, the mechanism of NCCLs in tooth abrasion has not been established. This study aims to develop a numerical method using a computational toothbrush to simulate NCCLs. The forces acting on the teeth and the amount of abrasion generated were evaluated. The discrete element method using in-house code, connected particle model, and Archard wear model were applied for brushing. In the toothbrush model, 42 acrylic tufts were fixed into a toothbrush head. The teeth models with enamel properties comprised four flat plates and two grooves to simulate the anterior teeth and NCCLs. The brushing speed and depth for one cycle were established as simulation parameters. The force applied within the ununiform plane was concentrated on several bristles as the toothbrush passed through the interproximal space. The brushing force (depth) had a greater effect on tooth abrasion than the brushing speed. Toothbrushing abrasion was mainly concentrated in the interproximal space. Therefore, forceful tooth brushing can cause NCCLs from the interproximal space to the cervical area of the tooth.

Effect of tapered-end and round-end bristles on the abrasive dentine wear applying increasing brushing forces.

OBJECTIVE: To investigate the effect of toothbrush bristles end configuration on the abrasive dentine wear at different brushing forces. MATERIAL AND METHODS: One hundred and sixty bovine dentine samples were randomized into eight groups (n = 20). Groups (1 to 4) were brushed with tapered-end bristles at 1-, 2-, 3-, and 4-N brushing forces, respectively. Groups (5 to 8) were brushed with round-end bristles with the same brushing forces. The brushing sequence was carried out using an abrasive slurry (RDA = 121) for 25 min. Profiles were recorded using a contact profilometer. Mean and standard deviation were calculated for the abrasive dentine wear in each group. Two-way ANOVA was used to locate any significance. The significance values were corrected after Tukey (α = 0.05). RESULTS: Brushing with tapered-end bristles resulted in statistically significantly less abrasive dentine wear than round-end bristles regardless of the applied brushing force (1 N: 4.4 ± 1.5 vs. 7.7 ± 2.0 µm; 2 N: 7.7 ± 2.1 vs. 12.2 ± 2.7 µm; 3 N: 11.3 ± 2.6 vs. 19.4 ± 3.7 µm; 4 N: 11.2 ± 2.1 vs. 25.3 ± 4.8 µm). The interaction between bristle configuration and brushing force was statistically significantly (p < 0.001). CONCLUSION: Tapered-end toothbrushes might be a safer choice for patients, especially when showing signs of non-carious cervical lesion. However, other toothbrush properties should also be considered.

Impact of desensitizing/whitening toothpastes on tooth color change after abrasion and erosion-abrasion.

OBJECTIVE: To evaluate the impact of desensitizing toothpastes (D), their whitening versions (DW) and whitening toothpastes (W) on tooth color change. METHODS: Tooth specimens were allocated into 11 groups (n = 10): 1. Artificial saliva (control); 2. Sensodyne Repair & Protect (SRP-D); 3. Sensodyne Repair & Protect Whitening (SRP-DW); 4. Colgate Sensitive Pro-Relief (CSPR-D); 5. Colgate Sensitive Pro-Relief Real White (CSPR-DW); 6. Colgate Total 12 (CT12); 7. Colgate Total 12 Whitening (CT12-W); 8. Sensodyne True White (ST-W); 9. Curaprox Black Is White (CB-W); 10.Oral-B 3D White Perfection (OB3D-W) and 11. Erosion-only. They were submitted to two models: A. abrasion; B. erosion/abrasion. Color change (ΔE00 ), ΔL, Δa, and Δb were determined with a spectrophotometer. Data were statistically evaluated (α = 0.05). RESULTS: For both models, ∆E00 of D did not differ significantly from DW. An overall decrease in luminosity (-∆L) and increase (+∆b) in yellowness of the tooth occurred. In abrasion, all groups reduced redness (-∆a) and only SRP-DW differed from control (p = 0.016), but for ∆E00 , ∆L and ∆b, all toothpastes did not differ from the control. In erosion/abrasion, CB-W showed significantly lower ∆E00 and ∆b than the control (∆E00 : p = 0.026; ∆b: p = 0.005) and SRP-D (∆E00 : p = 0.028; ∆b: p = 0.025). Only SRP-DW, CSPR-DW, ST-W, CB-W, and erosion-only had increased redness (+∆a), but none differed from control. CONCLUSIONS: The toothpastes did neither promote whitening nor avoid the yellowish aspect of the tooth after abrasion and erosion-abrasion, regardless of their claim. CLINICAL SIGNIFICANCE: Desensitizing and/or whitening toothpastes induced similar changes on tooth color, without promoting whitening effect or reduction in its yellowish aspect.

Diamond particles in toothpastes: in-vitro effect on the abrasive enamel wear.

BACKGROUND: Diamond particles have recently been used as abrasives in toothpastes, which raises questions about its abrasive behaviour towards enamel. This study was carried out to investigate the abrasive enamel wear caused by three diamond-loaded toothpastes (Candida White Diamond: CWD, Swiss Smile Diamond Glow: SSDG, Emoform F Diamond: EFD) and to compare it with a traditional toothpaste with silica abrasive (Colgate Total Original CTO). METHODS: Eighty bovine enamel samples were divided into four groups (n = 20) and brushed for 21,600 cycles (60 cycles/min) for 6 h at 2.5-N brushing force. The abrasive enamel wear was recorded with a contact profilometer. The median and interquartile range (IQR) of the abrasive enamel wear was calculated in each group. Pairwise comparisons were conducted using Wilcoxon signed rank exact test and the p value was adjusted according to Holm. Significance level was set at 0.05. RESULTS: Diamond-loaded toothpastes caused statistically significantly higher abrasive wear than the traditional toothpaste (p < 0.0001). SSDG caused statistically significantly higher enamel wear (19.0 µm (11.2)) than CWD (8.4 µm (4.6)) and EFD (7.3 µm (3.9)) (p < 0.0001). CONCLUSIONS: Diamond-loaded toothpastes cause higher enamel wear than toothpastes with traditional abrasives and also exhibit different abrasivity behaviour compared to each other.

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.