Analysis of dentin wear and biological properties promoted by experimental inoffice desensitizing materials.

BACKGROUND: This study aimed to evaluate dentin wear and biological performance of desensitizing materials. METHODS: Seventy bovine root dentin blocks were sectioned. Half of the surface of each specimen was untreated (control) and the other half was immersed in EDTA and treated with the following desensitizing materials: placebo varnish (PLA), fluoride varnish (FLU), sodium fluoride (NaF) varnish + sodium trimetaphosphate (TMP), universal adhesive (SBU), S-PRG varnish (SPRG), biosilicate (BIOS), and amelotin solution (AMTN). After application, the specimens were submitted to an erosive-abrasive challenge and the wear analyzed by optical profilometer. Serial dilutions of extracts obtained from the culture medium containing discs impregnated with those desensitizers were applied on fibroblasts and odontoblasts-like cells cultures. Cytotoxicity and production of total protein (TP) by colorimetric assays were determined after 24 h. Data were statistically analyzed using Kruskal-Wallis, Dunn's, One-way ANOVA and Tukey tests (p ≤ 0.05). RESULTS: No dentin wear was observed only for SBU. The lowest dentin wear was observed for AMTN and TMP. Cell viability was significantly reduced after treatment with undiluted extracts of PLA, FLU, TMP and SBU in fibroblasts and TMP and SBU in odontoblast-like cells. SPRG, BIOS and AMTN were cytocompatible at all dilutions tested. Considering TP results, no statistical difference was observed among the groups and high levels for TP were observed after TMP and FLU treatments. CONCLUSIONS: Universal adhesive system may protect dentin with opened tubules from wear after challenge. Extracts of adhesive and fluoride varnishes presented cytotoxic mainly on fibroblasts. The enamel protein may be a future alternative to treat dentin with opened tubules because it may cause low wear under erosive-abrasive challenge with low cytotoxic effects.

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.

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.

Weak Evidence Suggests Vegetarian Diets May Be Associated With an Increased Risk of Dental Erosion.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Vegetarian diet and its possible influence on dental health: A systematic literature review. Community Dent Oral Epidemiol. Smits KPJ, Listl S, Jevdjevic M. 2020; 48(1):7-13. SOURCE OF FUNDING: No financial support. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis.

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.

Protective Effect of Adhesive Systems associated with Neodymium-doped Yttrium Aluminum Garnet Laser on Enamel Erosive/Abrasive Wear.

AIM: This study evaluated the efficacy of self-etching adhesive systems associated or not associated with the neodymium-doped yttrium aluminum garnet (Nd:YAG) laser on the protection against enamel erosive/abrasive wear. MATERIALS AND METHODS: Bovine enamel specimens were demineralized with 0.3% citric acid (5 minutes). The samples were randomly assigned to eight groups (n = 20): SB - Single Bond Universal (3M/ESPE); SB+L - Single Bond Universal + laser (80 mJ/10 Hz); FB - Futurabond U (Voco); FB+L -Futurabond U + laser; GEN - G-aenial bond (GC); GEN+L -G-aenial bond + laser; L - laser irradiation; and C - no treatment. The laser was applied before light curing. The samples were subjected to erosive/abrasive challenges (0.3% citric acid - 2 minutes and tooth brushing four times daily for 5 days). Enamel surface loss was recovered profilometrically by comparison of baseline and final profiles. The adhesive layer thickness, retention percentage of the protective layer, and microhardness of cured adhesive were measured. Data were analyzed using one-way analysis of variance and Tukey's test (5%). RESULTS: There were significant differences for all parameters (p = 0.0001). Mean values ± SD and results of the Tukey's test were: Surface wear: GEN - 4.88 (±1.09)a, L - 5.04 ± 0.99)a, FB - 5.32 (±0.93)ab, GEN + L - 5.46 (±1.27)abc, SB + L - 5.78 (±1.12)abc, FB + L - 6.23 (±1.25)bc, SB - 6.35 (±1.11)c, and C - 6.46 (±0.61)c; layer thickness: GEN - 15.2 (±8.63)c, FB - 5.06 (±1.96)a, GEN + L - 13.96 (±7.07)bc, SB + L - 4.24 (±2.68)a, FB + L - 9.03 (±13.02)abc, and SB - 7.49 (±2.80)ab; retention: GEN - 68.89 (±20.62)c, FB - 54.53 (±24.80)abc, GEN + L - 59.90 (±19.79)abc, SB + L - 63.37 (±19.30)bc, FB + L - 42.23 (±17.68) a, and SB - 47.78 (±18.29)ab; microhardness: GEN - 9.27 (±1.75)c; FB - 6.99 (±0.89)b; GEN + L - 6.22 (±0.87)ab; SB + L - 15.48 (±2.51)d; FB + L - 10.67 (±1.58)c; SB - 5.00 (±1.60)a. CONCLUSION: The application of Futurabond U and G-aenial bond on enamel surface, as well as the Nd:YAG laser irradiation alone, was able to reduce the enamel wear. The use of laser after the adhesive systems did not improve their efficacy. CLINICAL SIGNIFICANCE: Erosive/abrasive wear is a prevalent condition in clinical practice affecting many patients. The association of adhesive systems and Nd:YAG laser is of considerable clinical interest because it assesses new treatments to reduce the erosive/abrasive wear that would help dentists in clinical treatment decisions to reduce enamel wear and achieve a successful treatment.

Influence of inter-dental tissues and root surface condition on complete root coverage following treatment of gingival recessions: a 1-year retrospective study.

AIM: To explore the influence of inter-dental tissues and root surface condition on complete root coverage following surgical treatment of gingival recessions. METHODS: Three hundred and eighty-six single recessions treated over 28 years were assessed. Patient-level and periodontal variables, presence/loss of inter-dental tissues, and presence/absence of non-carious cervical lesions (NCCLs) were recorded. Root coverage was assessed 1-year post-surgery. Multilevel analysis was performed to identify predictors of CRC. RESULTS: Based on type of root coverage procedure four patient groups were created: free gingival graft (FGG) (n = 116), coronally advanced flap (CAF) (n = 107), CAF+connective tissue graft (CTG) (n = 131), and guided tissue regeneration (GTR) (n = 32). Percentages of complete root coverage (CRC) were 18.1% for FGG, 35.5% for CAF, 35.1% for CAF+CTG, and 18.8% for GTR. There was an OR = 0.26 (p < 0.0001) of achieving CRC in cases with loss of inter-dental tissue compared with cases with no inter-dental tissue loss. Similarly, cases with presence of NCCL showed an OR = 0.28 (p < 0.0001) of achieving CRC compared with cases without a NCCL. FGG achieved less CRC then CAF+CTG (p = 0.0012; OR = 0.32). CONCLUSIONS: NCCLs, just like inter-dental tissue loss, are significant negative prognostic factors in achieving CRC following root coverage procedures.

Tooth color change promoted by different whitening toothpastes under alternate cycles of staining and brushing.

OBJECTIVES: To compare the effect of whitening toothpastes with different mechanisms of action on discolored teeth subjected to additional staining/or not. METHODS: One hundred twenty tooth specimens were stained for 14 days (staining broth under constant agitation and pH=7) and then allocated into the groups of toothpastes with different whitening ingredients (n=10): 1. Regular - Colgate Total 12 Clean Mint; 2. CLWI - Colgate Luminous White Instant (blue pigment); 3. CLWA - Colgate Luminous White Advanced Expert (hydrogen peroxide); 4. CLWAC - Colgate Luminous White Activated Charcoal (activated charcoal); 5. OB3D - Oral-B 3D WHITE Brilliant Fresh (abrasive); 6. TW - Teeth Whitening (charcoal powder). Specimens were submitted to two experimental models: A. Daily staining-toothbrush cycling: staining solution (5min), toothbrushing (45 strokes) and artificial saliva (3h), 2x/day, for 5 days; B. Only toothbrushing (30.000 brushing strokes). Color change was determined with a spectrophotometer (CIEDE2000 and Whiteness Index for Dentistry - WID) and statistically analyzed (α=0.05). RESULTS: For both models, ΔE00 and Δa did not differ significantly between the whitening toothpastes and the regular. All groups showed a decrease in tooth yellowness (-Δb) and an increase in WID. Group Teeth Whitening exhibited a decrease in luminosity (-ΔL). In model A, Groups did not differ significantly from the Regular in terms of ΔL (p=0.35) and Δb (p=0.74). Groups CLWI and OB3D exhibited a decrease in luminosity. Reduced redness (-Δa) occurred only in Group CLWI. In Model B, Groups OB3D (p=0.021) and CLWA (p=0.001) exhibited higher change in luminosity than in Group Teeth Whitening. All exhibited increased redness (+Δa) and lightness (+ΔL), except the Regular, CLWAC, and Teeth Whitening. Group OB3D had a significantly higher change in Δb than the Regular (p=0.021). CONCLUSIONS: Irrespective of the mechanism of action, all toothpastes reduced tooth yellowness and promoted similar overall color change. Exposure of the teeth to additional staining during the toothbrushing cycles did not influence the effect of the whitening toothpastes. CLINICAL SIGNIFICANCE: Whitening toothpastes should be tested in conditions that more closely simulate their use in a clinical scenario, in which alternate cycles of staining and brushing occur on a daily basis. However, even in such conditions, they were unable to promote a color change that differed from that of a regular toothpaste.

Excessive Dental Bleaching with 22% Carbamide Peroxide Combined with Erosive and Abrasive Challenges: New Insights into the Morphology and Surface Properties of Enamel.

This study aimed to evaluate the effects of 22% carbamide peroxide combined with an erosive challenge and simulated brushing on enamel. Bovine incisor teeth were divided into G1, tooth bleaching; G2, tooth bleaching + erosive challenge; and G3, tooth bleaching + erosive challenge + simulated brushing, and evaluated at T0, before any intervention; T1, 14 days after the proposed treatments; and T2, 28 days after the proposed treatments. Tooth bleaching was performed daily for 1 h for 28 days. The microhardness, surface roughness, mass variation, and ultrastructure were analyzed at T0, T1, and T2. Two-way analysis of variance for repeated measures was performed and Tukey's post hoc test (α = 5%) was used. The surface roughness increased in groups G2 and G3 as a function of time, whereas microhardness and mass measurements demonstrated a significant reduction for groups associated with challenges. Ultrastructural evaluation indicated a loss of the aprismatic layer and exposure of the enamel prisms in all groups after 14 days of bleaching, with more pronounced results in G2 and G3 after 28 days. In conclusion, abrasive and erosive challenges potentiated the deleterious effects of tooth whitening on microhardness, ultramorphology, and mass, without affecting the roughness of dental enamel.

The early wear susceptibility of cementum, enamel and dentine in vitro.

OBJECTIVES: To assess the differential early wear susceptibility of cementum, enamel and dentine at a micron level. METHODS: Whole human molar buccal surfaces incorporating natural enamel and cementum (n = 20) confirmed by imaging (digital microscopy: Keyence, VHX-7000 Milton Keynes, UK), were mounted, scanned (profilometry: XYRIS 4000, Taicaan, Southampton, UK), and allocated to receive erosion (citric acid, pH 2.7, 30 min (n = 10)) or erosion/abrasion challenges (3 cycles of (citric acid, pH 2.7, 10 min, 60 300 g linear abrasion strokes), n=10). Samples were polished and the experiment repeated on polished enamel, and polished coronal and radicular dentine within the same tooth. Profilometric wear data were obtained using superimposition: GeoMagic (3Dsystems, Darmstadt, Germany) and subtraction: MountainsMap (DigitalSurf, Besancon, France). Data were normal. A general linear model was used to assess differences between groups and substrates. RESULTS: The mean step height (SD) for natural enamel was 8.82 µm (2.53) for erosion and 11.48 µm (2.95) for erosion/abrasion. For natural cementum, the mean step height was 6.00 µm (2.29) for erosion and 4.67 µm (1.58) for erosion/abrasion. Dentine step heights ranged from 7.20 µm (1.53) for erosion and 9.79 µm (1.01) for erosion/abrasion with no statistical differences in dentine wear. Natural cementum surfaces had the lowest wear (p<0.001). Dentine had significantly less wear than natural enamel (p<0.02). CONCLUSIONS: Cementum surfaces demonstrated the most wear resistance, followed by dentine under erosion dominant conditions in this in vitro study. Further in-vivo investigations are needed to confirm the intraoral stability of cementum. CLINICAL SIGNIFICANCE: Cementum may be the least susceptible of dental substrates to wear and dentine does not wear at a faster rate than enamel under erosive conditions. This adds to our knowledge on the development of non-carious cervical lesions and questions whether wear rates will accelerate once dentine is exposed.

Temporomandibular Joint Pathology of Wild Carnivores in the Western USA.

Skull specimens from: southern sea otter (Enhydra lutris nereis), Eastern Pacific harbor seal (Phoca vitulina), California sea lion (Zalophus californianus), northern fur seal (Callorhinus ursinus), walrus (Odobenus rosmarus), polar bear (Ursus maritimus), North American brown bear (Ursus arctos), American black bear (Ursus americanus), California mountain lion (Puma concolor couguar), California bobcat (Lynx rufus californicus), gray fox (Urocyon cinereoargenteus), kit fox (Vulpes macrotis), and gray wolf (Canis lupus) (n = 5,011) were macroscopically examined for dental and temporomandibular joint (TMJ) pathology. The presence of temporomandibular joint osteoarthritis (TMJ-OA) varied across species: 4.1% of southern sea otter, 34.5% of harbor seal, 85.5% of California sea lion, 20% of northern fur seal, 60.5% of walrus, 9.2% of polar bear, 13.2% of North American brown bear, 50% of American black bear, 20.9% of California mountain lion, 0% of California bobcat and gray fox, 6.3% of kit fox, and 11.6% of gray wolf specimens had lesions consistent with TMJ-OA. TMJ-OA was significantly more prevalent in males than females in walrus, North American brown bear, polar bear, American black bear, and California mountain lion (p < 0.001, p = 0.005, p = 0.005, p = 0.002, and p = 0.004, respectively). No other species showed a sex predilection. Adult specimens were significantly more affected with TMJ-OA than young adults in the harbor seal, fur seal, walrus (all p < 0.001), and kit fox (p = 0.001). Gray wolf and American black bear young adults were significantly (p = 0.047 and p < 0.001) more affected by TMJ-OA than adults. Of the 13 species analyzed, only three species, namely the harbor seal, northern fur seal, and polar bear, had a significant increase in the prevalence of TMJ-OA if their teeth had attrition and abrasion (p < 0.001, p < 0.001, and p = 0.033, respectively). TMJ-OA can lead to morbidity and mortality in wild animals, but its etiology is not yet fully understood.

Three-Dimensional Surface Texture Characterization of In Situ Simulated Erosive Tooth Wear.

This in situ erosive tooth wear (ETW) study tested enamel 3-dimensional (3D) surface texture outcomes for the detection and differentiation of ETW lesions simulated in clinically relevant conditions. Twenty participants enrolled in this 3-arm crossover intraoral ETW simulation and wore their own partial denture for 14 d holding 2 human enamel specimens (per arm). In each arm, participants were assigned to 1 of 3 different dental erosion protocols: severe (lemon juice/pH 2.5), moderate (grapefruit juice/pH 3.5), and no erosion (bottled drinking water, control). Enamel specimens were evaluated by white-light scanning confocal profilometry for 3D surface texture and surface loss (ETW model validation). Individual point clouds were analyzed using standard dental microwear texture characterization protocols for surface roughness and anisotropy. Fractal complexity (Asfc), texture aspect ratio (Str), and arithmetical mean height (Sa) values were generated at baseline, 7 d, and 14 d. Data were analyzed by analysis of variance models suitable for the crossover design with repeated measurements, and correlation coefficients were used to examine the relationship between outcomes. Asfc and Sa differentiated ETW severity (no erosion < moderate < severe, P < 0.001) at days 7 and 14. Asfc and Sa were lower at baseline compared to days 7 and 14 (P < 0.001) for moderate and severe challenges. Asfc increased from day 7 to 14 (P = 0.042) for the severe challenge. For Str, ETW severity did not have a significant effect overall (P = 0.15). Asfc and Sa were highly positively correlated (r = 0.89, P < 0.001), while Asfc and Sa were not correlated overall with Str (r < 0.1, P ≥ 0.25). Enamel surface loss increased with ETW severity (no erosion < moderate < severe, P < 0.001) at days 7 and 14, validating the ETW simulation model. Complexity (Asfc) and roughness (Sa) outcomes were able to detect and differentiate ETW levels, with Asfc being able to monitor the progression of severe lesions. No clear characterization of ETW lesions could be provided by the anisotropy (Str) parameter.

Influence of toothbrush abrasion and surface treatments on the color and translucency of resin infiltrated hybrid ceramics.

PURPOSE: The study compared the color change, lightness, and translucency of hybrid resin ceramics exposed to toothbrush abrasion and surface treatment. MATERIALS AND METHODS: Four hybrid ceramics [Lava Ultimate (LU), Vita Enamic (EN), Shofu HC (SH), and Crystal Ultra (CU)] were compared with a glass-ceramic (Vita Mark II) control. One hundred and twenty specimen blocks were prepared using a precision saw machine. Specimens in each material were divided into four subgroups based on the surface treatment (polishing or staining) and a storage medium (water or citric acid). Simulated tooth brushing with a mixture of 100 RDA (radioactive abrasives) with 0.3 ml distilled water was used for 3650 cycles (7300 strokes) for each specimen. Measurements for the color change, lightness, and translucency were measured after toothbrushing using a spectrophotometer. Statistical analysis compared outcomes using paired t-test, ANOVA, and Tukey post hoc test. RESULTS: The maximum color change was identified in SH (stained acid) [1.44 (0.40)], whereas the lowest was identified in EN (polished water) [0.66 (0.16)] material. The maximum and minimum loss of surface translucency was observed in SH (polished water) [12.3 (0.52)] and EN (stained acid) [6.5 (0.55)] specimens, respectively. Lastly, loss of lightness was the highest in VM (polished acid) [69 (0.95)], whereas the lowest was observed in CU (stained water) [56.7 (0.86)]. CONCLUSION: The comparison presented a significant effect of toothbrush abrasion on translucency and lightness of the hybrid resin ceramics. Color change was not significantly influenced irrespective of the storage medium employed. Surface staining demonstrated the preservation and stability of color and optical properties under the influence of toothbrush abrasion and chemical trauma.

Erosive/Abrasive Enamel Wear While Using a Combination of Anti-Erosive Toothbrush/-Paste.

PURPOSE: To investigate dental enamel wear caused by erosion and abrasion while using a combination of anti-erosive toothbrush/-paste. MATERIALS AND METHODS: A total of 60 enamel specimens from bovine incisors were randomly assigned into five groups of 12 specimens each (G1-5, n = 12): (G1) control group (no treatment), (G2) standard medium toothbrush Paro M43 and standard toothpaste Elmex Caries Protection, (G3) standard medium toothbrush Paro M43 and anti-erosive toothpaste Elmex Protection Erosion, (G4) anti-erosive toothbrush Elmex Erosion Soft and standard toothpaste Elmex Caries Protection, (G5) anti-erosive toothbrush Elmex Erosion Soft and anti-erosive toothpaste Elmex Protection Erosion. Initially, surface baseline profiles were recorded using profilometry. In a total of 60 cycles, all specimens were exposed to hydrochloric acid (pH = 3) for 1 min, rinsed with tap water to stop the erosive attack and brushed according to the specific protocol of each group (15 brushing strokes per run). Enamel loss was determined by comparing the surface profiles before and after 60 cycles and the results were statistically analysed using analysis of variance (ANOVA). RESULTS: The significantly highest loss of enamel was observed in the control group G1(1.4 ± 0.20 µm) (p < 0.001). G2 turned out to be the most abrasive toothbrush/-paste combination (1.12 ± 0.15 µm), G3 the least invasive (0.40 ± 0.04 µm) (p < 0.001, respectively). CONCLUSION: All combinations of the investigated toothbrushes/-pastes reduce erosive/abrasive enamel wear. However, the highest reduction was observed for the combination of anti-erosive toothpaste and standard toothbrush (G3).

Clinical Study on Abfraction Lesions in Occlusal Dysfunction.

The abfraction theory states that under the action of the occlusal forces non-axially transmitted, the flexion of the tooth occurs in the cervical area, which initially leads to the appearance of cracks in the enamel and dentin, followed by the destruction of the dental structure. These lesions allow bacterial plaque retention, lead to dental hypersensitivity and can affect the vitality of the dental pulp. Thus, the study included 102 participants, of both sexes, 54% representing the male gender (55 subjects) and 46% the female gender (47 subjects), aged between 20 and 80, from the urban area 76% (77 subjects) and rural 24% (25 subjects), who came to the Dental Medicine office, between August 2018 and August 2019, representing 57.3%, of the total number of patients treated during the aforementioned period. They have been described the acid and abrasive processes involved in the generation of these lesions,and special attention was paid to the role of mechanical stress occurring at the occlusal level, due to the transmission of forces outside the dental axis.

Using fluoride mouthrinses before or after toothbrushing: effect on erosive tooth wear.

OBJECTIVES: 1. To evaluate the use of fluoridated mouthrinses before or after toothbrushing on erosive tooth wear. 2. To compare the anti-erosive effect of the combination toothpaste and mouthrinse containing fluoride, with or without stannous chloride. DESIGN: Enamel and dentin specimens were randomly distributed into groups (n = 10 of each substrate/group): B-brushing, B + R-brushing + rinsing, and R + B-rinsing + brushing. The treatments were performed using a fluoride toothpaste (BF: 1400 ppm fluoride, as amino fluoride-AmF) combined or not with a fluoride mouthrinse (RF: 250 ppm fluoride, as AmF and sodium fluoride-NaF) or fluoride and stannous toothpaste (BF+Sn: 1400 ppm fluoride, as AmF and NaF, 3500 ppm stannous, as stannous chloride-SnCl2 and 0.5% chitosan) combined or not with fluoride and stannous mouthrinse (RF+Sn: 500 ppm fluoride, as AmF and NaF, 800 ppm stannous, as SnCl2). As control, brushing was performed with artificial saliva (BC). Specimens were submitted to a 5-day erosive-abrasive cycling model. Treatments were performed twice daily. Surface loss (SL) was determined by optical profilometry. Data were analyzed by ANOVA and Games-Howell tests (α = 0.05). RESULTS: For enamel, RF+BF and RF+Sn+BF+Sn presented significantly lower SL than the control, with RF+BF being significantly lower than RF+Sn+BF+Sn. For dentin, BC had the lowest SL, not differing from BF+Sn+RF+Sn, RF+Sn+BF+Sn and BF. Groups RF+BF and BF+RF showed highest SL, not differing from BF+Sn and BF+Sn. CONCLUSIONS: For enamel, the use of a mouthrinse before brushing was able to reduce erosive wear for both fluoride and stannous products. For dentin, the use of stannous-containing products, irrespective of the order of application, presented superior effects.

Identifying the Etiological Factors Involved in the Occurrence of Non-Carious Lesions.

The study group comprised a total of 21 subjects (10 women and 11 men) from the urban area aged 20 to 72 who presented themselves to treatment at the Dental Office during July-December 2018. The purpose of the study was to identify the etiological factors responsible for the occurrence of non-carious lesions in the patients involved in the study. The study group of 21 patients (10 women and 11 men) from the urban area, aged 20 to 72 years, were clinically examined and dental impressions were obtained in order to ascertain the study patterns. Subjects diagnosed with non-carious lesions filled a questionnaire based on which the risk factors that led to these changes were identified. The study models were used to assess the degree of cervical tooth damage, according to SMITH-KNIGHT index. The main etiological factors found to be responsible for the occurrence of non-carious lesions in the studied group were the excessive consumption of acidic and carbonated beverages (71.42%), the presence of gastro-esophageal reflux disease (14.28%), incorrect technique of brushing (28.57%), vicious habits-nail biting (14.28%), daily consumption of sunflower seeds (9.52%), use of toothpicks as auxiliary hygiene (19.04%) and night teeth grinding (4,76%).

In vitro wear behavior between enamel cusp and three aesthetic restorative materials: Zirconia, porcelain, and composite resin.

PURPOSE: The aim of this study was to identify the effects of three aesthetic restorative materials on the wear between tooth and restoration by a pin-on-disk manner. MATERIALS AND METHODS: Six aesthetic restorative materials were used to prepare disk specimens for wear test, which were Lava Zirconia as zirconia group, Vintage MP and Cerabien ZR as veneering porcelain group, Gradia Direct microhybrid composite containing prepolymerized fillers, Filtek Z250 microhybrid composite containing zirconia glass and colloidal silica particles, and Filtek Z350 nanocomposite as composite resin group. Vertical loss of the worn cusp, change of the surface roughness of the restoration materials, and the surface topography were investigated after wear test under 9.8-N contact load. RESULTS: The porcelain groups (Vintage MP and Cerabien ZR) caused the largest vertical loss of teeth when compared with those of the composite resin and zirconia groups, and Filtek Z250 microhybrid composite results in the second-largest vertical loss of teeth. The surface of Filtek Z350 nanocomposite was deeply worn out, but visible wear on the surface of the zirconia and Gradia Direct microhybrid composite was not observed. When the zirconia surface was roughened by sand-blasting, vertical loss of teeth considerably increased when compared with that in the case of fine polished zirconia. CONCLUSION: It was identified that microhybrid composite resin containing a prepolymerized filler and zirconia with reduced surface roughness by polishing were the most desirable restorative materials among the tested materials to prevent the two-body wear between aesthetic restorative material and tooth.

Influence of desensitizing and anti-erosive toothpastes on dentine permeability: An in vitro study.

OBJECTIVE: This study analyzed the effect of desensitizing and/or anti-erosive toothpastes on dentine permeability. METHODS: One-mm dentin discs were prepared from human molars and exposed to EDTA solution (5 min, 17%). Initial dentine permeability was measured, under constant pressure. Specimens were randomly allocated into 10 groups: four anti-erosive toothpastes (calcium silicate + sodium phosphate, potassium nitrate, stannous chloride + chitosan, oligopeptide-104); four desensitizing toothpastes (arginine + calcium carbonate, calcium sodium phosphosilicate, strontium acetate, stannous fluoride); and two controls (regular fluoridated toothpaste, and human saliva). They were submitted to a 5-day erosion-abrasion cycling model. Erosion consisted of immersion in citric acid (2 min, 0.3%, natural pH ˜ 2.6, 4x/day), followed by 1 h exposure to human saliva. Specimens were brushed for 15 s (2 N, 45 strokes) with the toothpaste slurries (total exposure time of 2 min). After 5 cycles, the final dentine permeability was determined. Dentine permeability change was calculated as a percentage of the initial hydraulic conductance (%Lp). Data were analyzed with one-way ANOVA and Tukey tests (α=0.05). RESULTS: The toothpastes calcium silicate + sodium phosphate and potassium nitrate, showed significant decrease in %Lp, with no difference between them. The regular fluoridated toothpaste also decreased the %Lp, not differing from potassium nitrate. No desensitizing toothpaste showed change in %Lp. Human saliva, oligopeptide-104 and stannous chloride + chitosan presented significant increase in %Lp, without difference between them. CONCLUSION: Calcium silicate + sodium phosphate, potassium nitrate, and the regular fluoridated toothpaste decreased dentine permeability, whereas the desensitizing toothpastes tested did not. CLINICAL RELEVANCE: Toothpastes had distinct impacts on dentine permeability, which may reflect a variable effect on the treatment of dentine hypersensitivity. Within the limitations of a laboratory-based study, toothpastes with an anti-erosive claim could also be effective in reducing the pain in dentine hypersensitivity.