Adhesion of tooth fragment after trauma: effect of adhesion strategy and storage in the rescue box.

This study aims to investigate the impact of storage conditions for crown fragments (specifically, whether they were stored within a tooth rescue box or in tap water) on their adhesion to fractured teeth when subjected to two different adhesive systems (namely, total etch and self etch). Sixty maxillary premolars were sectioned to obtain tooth fragments. These fragments were stored briefly (2 hours) and reattached in the following groups: Group 1 (fragments stored in tooth rescue box and reattached with etch and rinse (E&R) technique), Group 2 (fragments stored in tap water and reattached with E&R technique), Group 3 (fragments stored in tooth rescue box and reattached with self-etch (SE) technique), and Group 4 (fragments stored in tap water and reattached SE technique). After reattachment, the bonded tooth fragments underwent thermal cycling (500 cycles, 5-55 °C) and bond strength testing using a universal testing machine. Two-way Analysis of Variance (ANOVA) and Tukey's tests were used for bond strength comparison (p ≤ 0.05). A two-parameter Weibull distribution was conducted to evaluate the reliability of the storage medium and adhesion modality on bond strength. The results showed that measured shear bond values (MPa ± Standard deviation (SD); arranged in descending order) for each group were: Group 2 (Tap water/E&R = 6.5 ± 2.1), Group 1 (Rescue box/E&R = 6.0 ± 2.5), Group 4 (Tap water/E&R = 5.1 ± 2.8), and Group 3 (Rescue box/SE = 3.6 ± 3.2). Significant differences were found only between Groups 2 and 3 (p = 0.002). In conclusion, storing crown fragments in a tooth rescue box did not significantly affect the shear bond strength of the restored tooth. However, fragments reattached using the self-etch technique showed comparable shear bond strength but a higher rate of adhesive failures compared to the E&R technique.

Influence of high-irradiance light curing on the marginal integrity of composite restorations in primary teeth.

BACKGROUND: Reducing the necessary time to restore primary teeth improves the cooperation of paediatric patients. This study aimed to investigate the marginal integrity of restorations prepared with a bulk-fill resin-based composite (RBC) containing additional fragmentation chain transfer (AFCT) compared to a conventional RBC when light cured with a rapid high-irradiance (3 s) and a regular (10 s) curing mode. METHODS: Forty class-II cavities were prepared in 40 primary molars. The molars were randomly divided into four groups based on the applied light-curing modes (regular: 10 s @ 1200 mW/cm2 or high-irradiance: 3 s @ 3000 mW/cm2) and the used restorative material (AFCT-containing bulk-fill RBC "Power Fill" or AFCT-free conventional RBC "Prime"). After thermo-mechanical loading, the marginal integrity was analysed using scanning electron microscopy. A beta regression model and pairwise comparisons were used to statistically analyse the data. RESULTS: The mean marginal integrity (% ± SD) of the restorations for each group was as follows: Power Fill (10 s: 79.7 ± 15.6) (3 s: 77.6 ± 11.3), Prime (10 s: 69.7 ± 11.1) (3 s: 75.0 ± 9.7). The difference between the RBCs for the same light-curing mode was statistically significant (p ≤ 0.05). The difference between the light-curing modes for the same RBC was not statistically significant (p ˃ 0.5). CONCLUSIONS: AFCT-containing bulk-fill RBC "Power Fill" achieves similar marginal integrity when light-cured with either high-irradiance or regular light-curing modes. "Power Fill" achieves better marginal integrity than the conventional RBC "Prime" regardless of the applied light-curing mode.

Molar-incisor hypomineralisation: Knowledge and perception of Syrian undergraduate and postgraduate dental students.

INTRODUCTION: Dentists' knowledge and expertise, especially in their early career, are primarily shaped during undergraduate studies. This cross-sectional study aimed to assess the knowledge and perception of Syrian under- and postgraduate students regarding diagnosing and managing molar-incisor hypomineralisation (MIH)-affected teeth. MATERIALS AND METHODS: Final-year dental students (FY-students), postgraduates in paediatric dentistry (PD-postgraduates) and postgraduates in other lines of specialty (OS-postgraduates) in all Syrian dental schools were invited to participate in an established web-based survey covering the knowledge and attitudes regarding the prevalence, aetiology, diagnosis and management of MIH. Data were analysed with descriptive statistics and Fisher's exact/chi-squared tests at 5%. RESULTS: In total, 1142 post- and undergraduate students from six public and five private dental schools in Syria participated in this study (867 FY-students, 74 PD-postgraduates and 201 OS-postgraduates). PD-postgraduates were found to present statistically significantly better knowledge regarding MIH compared with the two other groups. Only 19% of FY-students and 54% of OS-postgraduates reported themselves familiar with MIH (compared with 97% of PD-postgraduates). Similarly, 18% of FY-students and 27% of OS-postgraduates were capable of diagnosing MIH (compared with 81% of PD-postgraduates). Stainless-steel crowns and direct composite fillings were chosen as most suitable for treating MIH-affected molars from all responders. CONCLUSIONS: FY-students and even OS-postgraduates in Syria lack knowledge and confidence when confronted with MIH. The university curricula need to include more educational materials to equip the students with the necessary tools to manage MIH clinically.

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.

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.

Knowledge, perceptions, attitudes, and clinical experiences on molar incisor hypomineralization among Syrian pediatric dentists and general dental practitioners: a cross-sectional study.

BACKGROUND: Molar incisor hypomineralization (MIH) is a widespread oral health problem. Dentists encounter several challenges regarding MIH management worldwide. The aim of this study was to evaluate and compare the knowledge, perceptions, attitudes, and clinical experiences on MIH among general dental practitioners and pediatric dentists in Syria. METHODS: All general dental practitioners and pediatric dentists belonging to the Syrian Dental Syndicate of Damascus were invited to complete a cross-sectional structured questionnaire (n = 1936). The questionnaire consisted of four sections and required responses regarding demographic data, knowledge, perceptions, attitudes, and experiences on MIH. Data were analyzed with Pearson's chi-square test and multivariate regression models using SPSS Ver. 23.0. RESULTS: The overall response rate was 36.31% (703/1936). Pediatric dentists were significantly more familiar with MIH (p < 0.001) and more confident when diagnosing it (p < 0.001). Most participants (43.95%) perceived an increase in MIH prevalence in Syria. Stainless steel crowns were the most favorable restorative material for molars with post-eruptive breakdown (51.38%). As for molars and incisors with opacities, composite resin was preferred with (41.82%), and (67.51%) respectively. General dental practitioners requested further training regarding MIH treatment (p < 0.001). CONCLUSIONS: Pediatric dentists were equipped with further knowledge regarding MIH, and were more confident when diagnosing it. There is a need for additional training and education for general dental practitioners. Most respondents perceived an increase in the prevalence of MIH. There is a dearth of data regarding MIH prevalence in Syria. The materials of choice for restoring teeth with MIH were stainless steel crowns and composite resin.

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.

Knowledge, attitudes, and beliefs regarding molar incisor hypomineralisation amongst Swiss dental students.

BACKGROUND: Knowledge obtained at the undergraduate level regarding molar incisor hypomineralisation (MIH) has an impact on future practice of dentists and paediatric dentists. This cross-sectional study aimed to assess final-year dental students' knowledge, attitudes and beliefs towards MIH in all Swiss universities. METHODS: A previously utilised survey (in both English and German) was distributed among final-year dental students in all Swiss dental schools (Basel, Bern, Geneva and Zurich). It probed students' knowledge, attitudes and beliefs regarding the diagnosis, prevalence, aetiology, and management of MIH, and was structured in two parts: knowledge/perception and clinical application. The students' responses were analysed statistically with descriptive statistics. RESULTS: 113 out of 133 final-year Swiss dental students took part in the study (85%). Nearly all students were familiar with MIH (99%), but only 12% of them felt confident when diagnosing MIH clinically. Direct composite fillings (66%), indirect restorations (28%) and preformed stainless-steel crowns (26%) were chosen as most suitable treatment options for MIH-affected teeth. CONCLUSION: Final-year Swiss dental students are well informed about MIH. However, they report low level of confidence when clinically confronted with MIH-affected teeth regarding its diagnosis and treatment. Swiss Universities curricula should be revisited accordingly.

Effect of dentin pretreatment on the resulting abrasive dentin wear.

BACKGROUND: This study aims to investigate the influence of different dentin pretreatment procedures on the resulting abrasive dentin wear. METHODS: Two groups (A, B) of 60 dentin samples each were prepared. Group A was brushed with an abrasive slurry (RDA = 85) and group B with a different abrasive slurry (RDA = 174). Four subgroups in each group (n = 15) were created (A1-A4) and (B1-B4). The subgroups were pretreated as follows: A1 + B1 with 1200-grit grinding paper, A2 + B2 with 1200- and 2000-grit papers, A3 + B3 with 1200-, 2000-, and 4000-grit papers, A4 + B4 with 1200-, 2000-, 4000-grit papers and with 1000 brushing strokes with a slurry of Elmex toothpaste. All samples were brushed for 25 min at 120 strokes/min. Abrasive dentin wear was measured for each sample profilometrically and the subgroups were compared with each other within the same group. Repeated measures one-way ANOVA was conducted to compare the subgroups and pairwise contrasts were estimated for multiple testing according to Tukey (α = 0.05). RESULTS: The resulting abrasive dentin wear in group A ranged between 15.3 ± 3.4 µm and 17.3 ± 5.5 µm and between 20.3 ± 6.8 µm and 22.5 ± 2.6 µm in group B. No statistically significant difference was noticed between any subgroups within the same group (p ˃ 0.05). CONCLUSIONS: Different dentin pretreatment procedures do not affect the resulting abrasive dentin wear independent of the RDA value of the employed abrasive slurry.

Effect of a sonic toothbrush on the abrasive dentine wear using toothpastes with different abrasivity values.

OBJECTIVE: This in vitro study aimed to investigate the effect of a sonic toothbrush on the resulting abrasive dentine wear using toothpastes with different abrasivities compared to the use of a manual toothbrush. METHODS: Ninety-six bovine dentine samples were divided into six groups and subjected to a brushing sequence (sonic: 20 min, 0.9 N, 10 strokes/min; manual: 20 min, 1.6 N, 60 strokes/min) as follows: group 1: Elmex Sensitive Plus (RDA = 28) + manual toothbrush; group 2: Elmex Sensitive + sonic toothbrush; group 3: Elmex Kariesschutz (RDA = 65) + manual toothbrush; group 4: Elmex Kariesschutz +sonic toothbrush; group 5: Colgate Total Original (RDA = 121) + manual toothbrush; and group 6: Colgate Total Original +sonic toothbrush. The abrasive dentine wear was measured profilometrically. RESULTS: The median (IQR) abrasive dentine wear was as follows: Elmex Sensitive Plus (manual toothbrush: 2.7 µm (0.8), sonic toothbrush: 3.1 µm (1.9)); Elmex Kariesschutz (manual toothbrush: 4.9 µm (1.4), sonic toothbrush: 6.4 µm (2.1)); and Colgate Total Original (manual toothbrush: 5.2 µm (1.1), sonic toothbrush: 9.0 µm (3.1)). Differences in dentine wear between sonic and manual toothbrushes were statistically significant only in the groups brushed with Elmex Kariesschutz and Colgate Total Original (p ≤ 0.05). CONCLUSION: Brushing with a sonic toothbrush could result in a higher abrasive dentine wear compared to manual toothbrush when combined with toothpastes with high abrasivity values.

Effect of toothbrush bristle stiffness and toothbrushing force on the abrasive dentine wear.

OBJECTIVE: To investigate the influence of toothbrush bristle stiffness and applied brushing force on the resulting abrasive dentine wear in vitro. METHODS: One hundred sixty bovine dentine samples were randomly allocated in eight groups (n = 20). Groups one to four were brushed with a soft-bristle toothbrush with soft bristles applying 1, 2, 3 and 4 N brushing force, respectively. Groups five to eight were brushed with a medium-bristle toothbrush applying the same aforementioned brushing forces (120 strokes/min, abrasive slurry (RDA = 121), 25 min). Profiles were recorded before and after the brushing sequence, and the median and interquartile range of abrasive dentine wear were calculated and compared using two-way ANOVA and pairwise tests corrected after Tukey (α = 0.05). RESULTS: At 1, 2 and 3 N brushing force, the tested toothbrushes caused no significantly different abrasive dentine wear. At 4 N brushing force, the medium-bristle toothbrush caused statistically significantly higher abrasive force than the soft-bristle toothbrush. Using the medium-bristle toothbrush, abrasive dentine wear statistically significantly increased with increasing brushing force from 1 to 3 N. However, increasing the brushing force to 4 N did not result in statistically significantly higher wear. Using the soft-bristle toothbrush, abrasive dentine wear statistically significantly increased with increasing brushing force from 1 to 2 N. However, increasing the brushing force to 3 or 4 N did not result in statistically significantly higher wear. CONCLUSION: The soft-bristle toothbrush tends to cause less abrasive wear with increasing brushing force than the medium-bristle toothbrush.

Mechanical properties of toothpastes with diamond abrasives.

OBJECTIVE: The aim of this study was to evaluate and compare surface roughness, gloss, and color change of dental enamel after being brushed with toothpastes containing diamond powder and traditional abrasives. MATERIALS AND METHODS: Seventy enamel slabs were derived from 70 bovine incisors. The slabs were brushed with six different toothpastes and artificial saliva as a negative control. The specimens were then stained with black tea mixed with citric acid (3 days, pH = 4) and again brushed with the same toothpastes. Ra (contact profilometer), gloss (glossmeter), and color (CIE L* a* b* system) values were measured after each step. RESULTS: Emoform-F Diamond (contains diamond powder and traditional abrasives) offered significantly the best improvement of Ra and gloss values after the first brushing sequence and the best recovery of the brightness of enamel after staining and second brushing sequence (P < .05). AMC 2.5 (contains only diamond powder as abrasive) was not able to offer such improvement. CONCLUSION: Diamond powder as an additional abrasive in toothpastes could be able to offer a further improvement of Ra , gloss, and color values of enamel.

Initial bacterial adherence and biofilm formation on novel restorative materials used in paediatric dentistry.

OBJECTIVE: To evaluate the initial bacterial adherence and biofilm formation on novel restorative materials in paediatric dentistry and compare the results to stainless steel crown and primary enamel. MATERIALS AND METHODS: Twenty-five samples (Diameter = 4 mm) from five restorative materials (Tetric Power Fill light cured for 3 s or 10 s, Fuji II LC, Equia Forte HT Fil, Cention Forte, Stainless-steel crown) and primary enamel were prepared. Four samples served for recording of surface roughness (Ra) using a contact profilometer, 21 samples were incubated in stimulated human saliva for 2 h (initial bacterial adherence) and 72 h (biofilm formation) and served to determine ion releasing and bacterial growth. After 2 and 72 h, the number of colony-forming units (CFU) per ml was counted and expressed in Log10 CFU/ml. Data were analysed with two-way ANOVA and Tuckey's multiple comparisons test (p < 0.05). RESULTS: All tested materials showed similar initial bacterial adherence (p > 0.1). Stainless steel crown showed statistically significantly less biofilm formation than all other tested materials (p ≤ 0.02), except for Fuji II LC (p = 0.06). In terms of biofilm formation, the differences between all tested materials were not statistically significant (p ≥ 0.9). SIGNIFICANCE: Novel restorative materials in paediatric dentistry show similar initial bacterial adherence and biofilm formation. However, compared to other restorative materials, stainless steel crowns demonstrate the lowest level of biofilm formation. Ion-releasing materials may not necessarily show better antimicrobial properties than conventional materials.

In-Vitro Tooth Cleaning Efficacy and Filament End Rounding of Different Manual Children's Toothbrushes.

PURPOSE: This in-vitro study aimed to investigate the cleaning efficacy of 18 different manual children's toothbrushes applying horizontal, vertical, and rotational movements, as well as to evaluate the rounding of their filament ends. MATERIALS AND METHODS: Models equipped with artificial teeth (coated with titanium dioxide) were brushed using a brushing machine with clamped manual children's toothbrushes. The machine carried out horizontal, vertical, and rotational movements for 1 min with a constant contact pressure of 100 g. The percentage of the area of titanium dioxide removed from the buccal, mesial, distal and total surfaces of the artificial teeth corresponded to the cleaning efficacy. To assess the filament design, a scanning electron microscope was used to check the morphology of the filaments which was scored with Silverstone and Featherstone scale. SPSS 22 was used for data analysis. RESULTS: The rotational and the vertical movements achieved the best cleaning efficacy with all tested toothbrushes. The vast majority of the tested toothbrushes had their poorest cleaning efficacy in the horizontal movement. Only a small part of the children's toothbrushes (3 out of 18) had a correct and acceptable proportion of rounded bristle ends. CONCLUSIONS: Based on the present results, it could be concluded that the cleaning efficacy of different manual children's toothbrushes varied considerably. The best cleaning efficacy was almost always observed for rotational and vertical movements.

Cleaning performance of electric toothbrushes around brackets applying different brushing forces: an in-vitro study.

Throughout treatment with fixed orthodontic appliances, effective plaque control is crucial to maintaining dental health. This in-vitro study evaluated the cleaning performance of eleven different brush heads of seven electric toothbrushes (oscillating-rotating and sonic motions) and varying brushing forces around orthodontic brackets. Six Mini Diamond® Twin brackets were placed on black-stained front teeth. Teeth were coated with white titanium oxide and brushed in a machine six times for one minute with two different brushing forces (1 N and 1.5 N). Eleven different brush heads were evaluated (either oscillating-rotating or sonic movements). The teeth were scanned and planimetrically evaluated after brushing. Three detailed plaque areas (DPAs) were created: proximal (< 1 mm to bracket), mid-tier (1-2 mm to bracket), and distant (> 2 mm to bracket). The proportion of contaminated proximal, mid-tier, and distant surfaces (white regions) in relation to the respective DPA was calculated. Independent of brushing forces, places with a higher distance (> 2 mm) to the orthodontic bracket had the least amount of residual contamination, followed by areas with a minor (1-2 mm) and proximal distance (< 1 mm). In all of the brushes tested and for both estimated brushing forces, the region with the highest residual contamination was the proximal area. The brush heads of the Paro® Sonic toothbrush left the least amount of residual contamination. The cleaning performance of electric toothbrushes around brackets on upper incisors varied across the brushes examined. The proximal area has the most residual contamination. Furthermore, 9 out of 11 toothbrushes cleaned more successfully with 1.5 N than with 1 N brushing force.

Abrasive Enamel and Dentin Wear Resulting from Brushing with Toothpastes with Highly Discrepant Relative Enamel Abrasivity (REA) and Relative Dentin Abrasivity (RDA) Values.

PURPOSE: To investigate the absolute wear caused by toothpastes with highly discrepant REA (Relative Enamel Abrasivity) and RDA (Relative Dentin Abrasivity) values on both enamel and dentin: Candida Peppermint (CP; REA: 1; RDA: 42), Colgate Total Original (CTO; REA: 4; RDA: 100), Signal White System (SWS; REA: 8; RDA: 143), and Candida White Diamond (CWD; REA 244; RDA: 12). MATERIALS AND METHODS: Eighty (80) bovine enamel samples and 80 dentin samples were divided into four groups each (n = 20) and investigated after a 6-h brushing procedure (21,600 cycles, 60 cycles/min, load of 2.5 N) with the four toothpastes. The abrasive enamel and dentin wear were registered using a contact profilometer. The median and interquartile range (IQR) of the abrasive enamel and dentin wear were calculated for each group. Pairwise comparisons were conducted using the Wilcoxon signed-rank exact test, and the p-value was adjusted according to Holm (statistical significance set at 0.05). RESULTS: CWD led to the highest abrasive enamel wear (9.86 µm [5.77]). CTO caused the highest abrasive dentin wear (166.70 µm [69.90]), being statistically significantly higher than the wear for CP (54.20 µm [24.00]) and CWD (17.00 µm [7.80]) (p = 0.00001). The abrasive dentin wear for CWD was statistically significantly lower in comparison to all other groups (p = 0.00001). CONCLUSION: Toothpastes with highly discrepant REA and RDA values presented statistically significantly different absolute wear on enamel and dentin. REA and RDA values should both be declared for every toothpaste.

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.

Marginal Integrity of Simplified Adhesive Strategies in Primary Teeth.

OBJECTIVE: The aim of this research was to investigate the effect of simplified adhesive strategies (self-etch vs selective enamel etch and 10- vs 20-second adhesive application time) on the marginal integrity in primary molars. METHODS: Forty deep class-II cavities were prepared in 40 extracted primary molars. The molars were divided into 4 groups based on the applied universal adhesive strategy as follows: groups 1 and 2: selective enamel etch with 20- or 10-second application time and groups 3 and 4: self-etch with 20- or 10-second application time. All cavities were restored with a sculptable bulk-fill composite restoration. The restorations underwent a thermomechanical loading (TML, 5-50 °C, 2-minute dwelling time, ×1000; 400,000 loading cycles, 1.7 Hz, 49 N). Marginal analysis before and after TML was conducted with scanning electron microscopy and the marginal integrity of each restoration was calculated as a percentage of continuous margins. A beta regression model was adopted to statistically analyse the data with a consequent pairwise comparison. RESULTS: The mean marginal integrity (% ± SD) of the restorations for each tested adhesive strategy after TML was as follows: selective enamel etch/20 seconds = 85.4 ± 3.9, self-etch/20 seconds = 85.3 ± 5.2, self-etch/10 seconds = 80.1 ± 8.2, and selective enamel etch/10 seconds = 80.0 ± 8.5. The difference between both adhesive strategies was not statistically significant at the same application time. The difference between both application times within the same adhesive strategy was statistically significant (P ≤ .01). CONCLUSIONS: Universal adhesives applied either in selective enamel etch or in self-etch mode result in comparable marginal integrities when restoring class-II cavities in primary molars. Shortened adhesive application time (10 seconds) could lead to a reduction in the marginal integrity in comparison to the recommended application time of 20 seconds.