Bovine Enamel Research Articles

Effect of TiF4/NaF and chitosan solutions on the development of enamel caries under a microcosm biofilm model

ObjectivesTo evaluate the effect of experimental solutions containing TiF4/NaF and chitosan on bacterial species and on enamel caries prevention. MethodsMicrocosm biofilm was produced from human saliva mixed with McBain saliva (0.2% sucrose) on bovine enamel for five days, under 5% CO2 and 37 °C. From the second day until the end, the treatments were applied (1 × 60 s/day): (1) NaF (500 ppm F−, positive control); (2) TiF4 and NaF (TiF4: 190 ppm Ti4+ and 300 ppm F−; NaF: 190 ppm F−); (3) similar to 2 plus 0.5% chitosan (Ch 500 mPas, 75% deacetylation); (4) phosphate buffer solution (negative control); and (5) 0.5% chitosan (Ch 500 mPas, 75% deacetylation). CFU counting was performed for total microorganism, total streptococcus, total lactobacillus and Streptococcus mutans. Enamel demineralization was measured by transverse microradiography-TMR. The data were compared using ANOVA/Tukey or Kruskal-Wallis/Dunn tests (p < .050). ResultsNo differences were found between the treatments with respect to CFU counting (ANOVA, p > .050). Enamel treated with TiF4/NaF plus chitosan solution presented the lowest demineralization compared to the negative control and pure chitosan solution. On the other hand, this experimental solution did not significantly differ from TiF4/NaF and NaF solutions, being all of them able to significantly reduce mineral loss (50–74%), but only TiF4/NaF plus chitosan reduced lesion depth (55%) compared to the negative control (p = .001). ConclusionTiF4/NaF plus chitosan solution had no antimicrobial effect, but it was able to reduce enamel caries development in 79% compared to control under this model. Clinical significanceThis study showed that TiF4/NaF plus chitosan solution had no antimicrobial effect, but it was able to reduce enamel caries development under a microcosm biofilm model.

Cariogenic Potential of Human and Bovine Milk on Enamel Demineralization

The higher cariogenicity of human milk when compared with bovine milk is still a debatable subject. Therefore, we evaluated the effect of human or bovine milk exposure on biofilm composition and enamel demineralization using a validated cariogenic biofilm model. Streptococcus mutans UA159 biofilms (n = 8) were grown on human saliva-coated bovine enamel slabs of known surface hardness. The biofilms were exposed 8×/day to 0.9% NaCl (negative control), human milk, bovine milk, 7.0% lactose (active human milk control), 4.5% lactose (active bovine milk control), or 10% sucrose (positive control). The culture medium was changed twice daily, and the pH was analyzed as an indicator of biofilm acidogenicity. After 120 h of growth, biofilms were harvested to evaluate viable cells, and soluble and insoluble extracellular polysaccharides (EPS). Enamel demineralization was assessed by the percentage of surface hardness loss (%SHL). Data were analyzed by one-way ANOVA/Tukey’s test (α = 5%). In terms of %SHL, negative control (7.7 ± 3.1), human milk control (13.3 ± 7.5), bovine milk control (15.3 ± 8.2), human milk (7.5 ± 5.0), and bovine milk (8.7 ± 6.3) did not differ among them (p > 0.05) but differed (p < 0.05) from sucrose (55.1 ± 5.4). The findings of enamel demineralization (%SHL) were statistically supported by the data of biofilm acidogenicity, bacterial counts and EPS biofilm composition. This experimental study suggests that human and bovine milk have low cariogenic potential to provoke caries lesions in enamel.

Electrochemical mineralization of iron-tannate stain on HAp and bovine enamel-A non-peroxide approach

Prolonged treatments for the destaining of teeth using high concentrations of hydrogen peroxide may cause secondary unwanted effects such as tooth hypersensitivity and gingival irritation. Hence, it is aimed to develop a non-peroxide-based method to oxidize iron-tannate (Fe-TA) stained hydroxyapatite (HAp) and bovine enamel (BE) samples. Constant current electrolysis (CCE) experiments were carried out on Pt working electrode in aqueous NaCl, KCl and KI solutions at discrete concentrations under continuous experiment and a non-continuous experiment. CCE shows that in the presence of iron tannate (Fe-TA) stained HAP, approximately 30 ppm of iodine was generated using 0.1M KI and nearly 40 ppm was produced with 0.2 M KI. By using a non-continuous CCE process, the lowest amount of chlorine was generated from NaCl solution, which was well within the safety limits for oral applications. Depending on the experimental conditions used, between 13 ppm and 124 ppm of chlorine was generated. CCE of Fe-TA stained on HAp using KCl reveals that at the lowest current density of 10 mA/cm2, the amount of hypochlorite generated was 20 ppm on Pt electrode having a surface area of 6 cm2. Ion chromatographic (IC) analysis revealed that non-continuous CCE of Fe-TA-BE in NaCl generated a low concentration of sodium perchlorate (0.8 ppm), whereas the continuous process generated no perchlorate, but a considerable higher quantity of chlorate for Fe-TA-BE (37 ppm) and Fe-TA-HAp (140 ppm) samples.

Bleaching and microstructural effects of low concentration hydrogen peroxide photoactivated with LED/laser system on bovine enamel

BackgroundTooth whitening protocols with low concentration hydrogen peroxide (HP) appear to minimize the microstructural effect on teeth. In addition, light sources have been used to enhance bleaching efficiency. This study evaluated the color change and microhardness of a protocol with 6% HP photoactivated by LED/laser in comparison with 35% HP. MethodsTwenty bovine incisors were randomized in two groups: 6% HP + LED/laser and 35% HP (n=10). Teeth were submitted to staining using dark tea. Three whitening sessions were carried out according to the manufacturer's instructions. Enamel microhardness (VHN) and color change evaluation (∆L*, ∆a*, ∆b*, ∆E00 [CIEDE2000], and WID) before 24 hours and 7 days after the last whitening session were performed. Two-way repeated ANOVA and Bonferroni post-test was used (α = 0.05). ResultsBoth groups showed perceptible color changes, being more pronounce for 35% HP. Differences were observed for ∆a*, ∆b* and ∆E00 (p≤0.027), except for ∆L* (p>0.05). Differences were also found in the comparison among the evaluation times within the same group (p≤0.027), except for ∆a* results (p>0.05). WID showed that 35% HP exhibited high whiteness values. Regarding microhardness, the groups did not show significant differences (p>0.05). However, 35% HP showed decreased values after 7 days of the last whitening session compared to the baseline (p≤0.027). Conclusions6% HP + LED/laser promoted perceptible color change, but not comparable with 35% HP. No differences on enamel microhardness were observed between the whitening protocols. However, 35% HP showed decreased hardness after 7 days of whitening compared to baseline.

Effect of Spondias mombin L. extract on the wettability, roughness, color and morphology of bovine enamel

Although Spondias mombin L. extract has an excellent antimicrobial effect against oral microorganisms, it should be clarified how it affects enamel surface properties. Aim: To evaluate the color change, wettability/contact angle, surface roughness and morphology of bovine enamel submitted to the Spondias mombin L. extract. Methods: Thirty bovine teeth were distributed into the following groups: 0.12% chlorhexidine digluconate, 1:32 Spondias mombin L. extract and distilled water. Color change (CC) was evaluated after immerging specimens into the solutions for 14 days. Surface roughness (Ra) was measured using a roughness meter; wettability/contact angles (CA) were determined by the sessile drop method, and scanning electron microscopy images were obtained to characterize the morphology (SMA). The pH of the solutions was evaluated using a pHmeter. The Ra, CA, and CC data were parametric (Kolmogorov-Smirnov; p&gt;0.05). Two-way ANOVA (for Ra and CA) and one-way ANOVA (for CC) with Tukey’s posthoc tests at a significance level of 5% were used. SMA was analyzed descriptively. Results: The Spondias mombin L. extract revealed an acidic pH, and when in contact with the bovine teeth, it increased the wettability, but it did not cause statistically significant differences in the Ra. Spondias mombin L. extract caused the highest color change. The SEM images showed differences in the specimens’ surface submitted to the extract compared to the other groups. Conclusion: Spondias mombin L. extract provided negative effects on bovine enamel’s surface, including a high color change and a more wettable substrate.

The Effect of Solutions Containing Extracts of Vochysia tucanorum Mart., Myrcia bellaCambess., Matricaria chamomilla L. and Malva sylvestris L. on Cariogenic Bacterial Species and Enamel Caries Development

This study evaluated the effect of experimental solutions containing plant extracts on bacterial species and enamel caries prevention. Microcosm biofilm was produced from human saliva mixed with McBain saliva (0.2% sucrose) on bovine enamel for 5 days (3 days under anaerobiosis and 2 days under aerobiosis) at 37°C. From the 2nd day, the following treatments were applied (1 × 60 s/day): Vochysia tucanorum (10 mg/mL); Myrcia bella (5 mg/mL); Matricaria chamomilla (80 mg/mL); Malva sylvestris, fluoride, and xylitol (Malvatricin Plus®); 0.12% chlorhexidine (CHX, PerioGard®); and PBS (negative control). The medium pH was measured. Quantitative polymerase chain reaction was performed for the detection of Streptococcus mutans and Lactobacillus spp. Enamel demineralization was measured by spectral-domain optical coherence tomography. The data were compared by means of the Kruskal-Wallis/Dunn, two-way ANOVA/Bonferroni, and ANOVA/Tukey tests (p < 0.05). The pH decreased after sucrose exposure; only CHX reestablished pH >5.5 by the last day. CHX also eliminated Lactobacillusspp., but the other treatments did not differ significantly from PBS. Malvatricin Plus® and CHX eliminated S. mutans, but the other treatments did not differ from PBS. Similar results were seen concerning the reduction of lesion depth and reflectivity. The experimental natural-extract solutions were ineffective against cariogenic bacteria and in preventing the development of enamel caries.

Safety and In Situ Antierosive Effect of CaneCPI-5 on Dental Enamel

The sugarcane cystatin (CaneCPI-5) was recently cloned and showed strong binding force to dental enamel and protection against initial erosion. However, evaluations on its safety and efficacy in a situation closer to the clinical condition are necessary. In the present study we analyzed 1) the cytotoxicity of CaneCPI-5 on human gingival fibroblasts (HGFs); 2) the ability of CaneCPI-5 to reduce enamel erosion and erosion+abrasion in situ. In part 1, HGFs were treated with CaneCPI-5 (0.025, 0.05, 0.1, 0.5 or 1.0 mg/mL) or no treatment (control). The cytotoxicity was assessed after 60 s and 24 h by mitochondrial activity (MTT), confocal microscopy, and hematoxylin/eosin staining. In part 2, 15 volunteers participated in a double-blind crossover protocol consisting of 3 phases, according to the following treatments: 1) 0.1 mg/mL CaneCPI-5; 2) SnCl2/NaF/AmF (Elmex; positive control); 3) water (negative control). The volunteers wore an appliance containing 4 bovine enamel specimens for 5 d. Each day, the specimens were individually treated with 50 µL of the tested solutions per 60 s and then subjected to erosive challenges (0.1% citric acid, pH 2.5, for 90 s, 4 times per day). After the first and last erosive challenge each day, 2 samples were abraded (toothbrushing, 15 s). Enamel wear was measured by contact profilometry. One or two-way analysis of variance (ANOVA)/Tukey’s or Sidak’s tests (P < 0.05) were applied. Regardless of the concentration and the experimental time, CaneCPI-5 did not decrease the cell viability compared to the negative control (P < 0.05). Erosion+abrasion led to significantly greater wear compared to erosion only. For both conditions, the lowest wear was found for SnCl2 and CaneCPI-5, which did not differ significantly from each other, but showed significant protection when compared to the negative control. In conclusion, CaneCPI-5 is safe on HGFs and reduces enamel erosive wear to the same extent as a commercial solution used to control erosive tooth wear (ETW).

Antimicrobial and anti-caries effects of a novel cystatin from sugarcane on saliva-derived multi-species biofilms.

This study evaluated the antimicrobial (anti-biofilm) and anti-caries (enamel demineralization prevention) effects of a new cystatin derived from sugarcane (CaneCPI-5). Microcosm biofilm was produced on bovine enamel specimens (4 x 4 mm; n=48) from a mixture of human saliva and McBain saliva at the first 8 h. From this moment until the end of the experiment, the enamel specimens were exposed to lsaMcBain saliva containing 0.2% sucrose and, once a day, they were treated with the test solutions for 1 min. This treatment was performed for 5 days. The solutions evaluated were: PBS (negative control), 0.12% chlorhexidine (positive control), 0.1 mg/ml CaneCPI-5 and 1.0 mg/ml CaneCPI-5. The biofilm viability was determined by fluorescence using confocal microscopy and the enamel demineralization was quantified using transverse microradiography (TMR). The data were analyzed by ANOVA/Tukey or Kruskal-Wallis/Dunn tests for biofilm and enamel, respectively (p<0.05). With respect to the antimicrobial effect, all treatment solutions significantly reduced the biofilm viability compared with PBS. The best antimicrobial effect was found for 1.0 mg/ml CaneCPI-5 (82.37±10.01% dead bacteria) that significantly differed from 0.12% chlorhexidine (73.13±15.07% dead bacteria). For the anti-caries effect, only 0.12% chlorhexidine (ΔZ: 2610, 1683-4343) performed significantly better than PBS (ΔZ: 8030, 7213-9115), but 0.12% chlorhexidine did not significantly differ from 0.1 mg/ml Cane-CPI-5. Under this experimental model, CaneCPI-5 significantly reduced the biofilm viability, but this effect was not reflected on its anti-caries potential.

Antimicrobial and anti-caries effects of a novel cystatin from sugarcane on saliva-derived multi-species biofilms.

This study evaluated the antimicrobial (anti-biofilm) and anti-caries (enamel demineralization prevention) effects of a new cystatin derived from sugarcane (CaneCPI-5). Microcosm biofilm was produced on bovine enamel specimens (4 x 4 mm; n=48) from a mixture of human saliva and McBain saliva at the first 8 h. From this moment until the end of the experiment, the enamel specimens were exposed to lsaMcBain saliva containing 0.2% sucrose and, once a day, they were treated with the test solutions for 1 min. This treatment was performed for 5 days. The solutions evaluated were: PBS (negative control), 0.12% chlorhexidine (positive control), 0.1 mg/ml CaneCPI-5 and 1.0 mg/ml CaneCPI-5. The biofilm viability was determined by fluorescence using confocal microscopy and the enamel demineralization was quantified using transverse microradiography (TMR). The data were analyzed by ANOVA/Tukey or Kruskal-Wallis/Dunn tests for biofilm and enamel, respectively (p<0.05). With respect to the antimicrobial effect, all treatment solutions significantly reduced the biofilm viability compared with PBS. The best antimicrobial effect was found for 1.0 mg/ml CaneCPI-5 (82.37±10.01% dead bacteria) that significantly differed from 0.12% chlorhexidine (73.13±15.07% dead bacteria). For the anti-caries effect, only 0.12% chlorhexidine (ΔZ: 2610, 1683-4343) performed significantly better than PBS (ΔZ: 8030, 7213-9115), but 0.12% chlorhexidine did not significantly differ from 0.1 mg/ml Cane-CPI-5. Under this experimental model, CaneCPI-5 significantly reduced the biofilm viability, but this effect was not reflected on its anti-caries potential.

Influence of the acid erosion associated with dental bleaching in bovine enamel: In vitro study

Objective: To evaluate the influence of acid erosion caused by the daily intake of lemon juice or apple cider vinegar, associated with immediate dental whitening, on bovine enamel. Materials and Methods: 30 bovine teeth were sectioned to obtain enamel blocks and were distributed into three groups (n = 10): G1- Tooth whitening with 35% hydrogen peroxide; G2- Tooth whitening with 35% hydrogen peroxide + lemon juice and G3 - Tooth whitening with 35% hydrogen peroxide + apple cider vinegar. Treatments were performed for 21 days, the varnish was removed and the analysis of loss of structure and surface roughness were performed by means of non-contact 3D Confocal Chromatic Profilometer. The roughness data obtained were analyzed by Kruskal-Wallis and Mann-Whitney non-parametric tests. Results: All groups exhibited greater roughness (Sa) on the side exposed to the treatments (G1 = 3.17b; G2 = 4.17b; G3 = 3.99b) compared to the unexposed side (G1 = 2.55a; G2 = 3.94a; G3 = 2.40a). There was a statistically significant difference among the groups evaluated, being G1 (3.17A) &lt;G3 (3.99C) &lt;G2 (4.17B). Conclusion: 35% hydrogen peroxide has the least erosive potential when compared to its association with vinegar and to lemon juice.

A novel non-destructive technique for qualitative and quantitative measurement of dental erosion in its entirety by porosity and bulk tissue-loss

ObjectiveTo explore the potential of combining non-contact profilometry (NCP) and confocal laser scanning microscopy (CLSM) data to measure the entire erosive process non-destructively and to validate findings using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), scanning electron microscopy (SEM) and surface microhardness (SMH) using the same samples throughout. MethodsPolished bovine enamel samples (n = 35) were divided into groups (7/group) with similar SMH values. Samples underwent individual erosive challenges (1 % citric acid, pH3.8) for 1, 5, 10, 15 or 30 min under stirring and aliquot extracts were analysed for Ca and P by ICP-AES. SMH was used to measure erosive softening. Profilometry was used to assess bulk volume loss (BVL). Images were captured by SEM. Samples were stained with rhodamine-B (0.1 mM, 24 h) and images captured by CLSM. Image processing was used to determine changes in fluorescent volume for the first 10 μm (ΔFV10) for each enamel sample which were combined with BVL to calculate total lesion volume (TLV). ANOVA, linear regression and Pearson correlation analysis were used where applicable. ResultsSurface softening, [Ca], [P], BVL and ΔFV10μm increased with acid erosion duration which were significant by 10 min (P < .01). The Ca:P ratio increased to 1.57 then decreased after 5 min erosion suggesting a sub/surface phase change, which was observed by SEM and CLSM showing significant changes to the enamel surface and subsurface morphology with time. Combination of BVL and ΔFV10 as TLV strengthened the significant correlations with [Ca], [P], and SMH (P < .01). ConclusionThis novel combination of CLSM and NCP allows for concurrent non-destructive quantification of the entire erosive process by mineral loss, and qualitatively characterise microstructural changes during dental erosion.

Influence of primer contamination on the bonding interface of enamel pre-etched with phosphoric acid.

In this study, the influence of primer contamination on enamel bonding was analyzed. Adper Scotchbond Multi-Purpose (SMP), CLEARFIL SE Bond 2 (SE2), Scotchbond Universal (SBU) Adhesive, and Scotchbond Etchant (35% phosphoric acid; PA) were used. Ground bovine enamels were divided into eight groups based on the bonding protocols. The bonding interfaces after an acid-base challenge were observed via scanning electron microscopy to determine the acid-base resistant zone (ABRZ). Moreover, the bonding interfaces after the nanoleakage challenge were analyzed via energy-dispersive X-ray spectroscopy. ABRZ was observed in all the samples except PA_ONLY (applied PA etching, No primer and No adhesive resin). The funnel-shaped erosion was detected only in X_SBU (applied SBU without PA etching). The nanoleakage test revealed silver patterns in some groups. The nanoleakage, i.e., the penetration of the silver ions, was detected in the groups wherein primer was applied on PA-pre-etched enamel.

Potential of different fluoride gels to prevent erosive tooth wear caused by gastroesophageal reflux

BackgroundThis in-vitro-study aimed to evaluate the potential of different fluoride gels to prevent gastroesophageal reflux induced erosive tooth wear.MethodsSurface baseline profiles of a total of 50 bovine enamel specimens [randomly assigned to five groups (G1–5)] were recorded. All specimens were positioned in a custom made artificial oral cavity and perfused with artificial saliva (0.5 ml/min). Reflux was simulated 11 times a day during 12 h by adding HCl (pH 3.0) for 30 s (flow rate 2 ml/min). During the remaining 12 h (overnight), specimens were stored in artificial saliva and brushed twice a day (morning and evening) with a toothbrush and toothpaste slurry (15 brushing strokes). While specimens in the control group (G1) did not receive any further treatment, specimens in G2–5 were coated with different fluoride gels [Elmex Gelée (G2); Paro Amin Fluor Gelée (G3); Paro Fluor Gelée Natriumfluorid (G4); Sensodyne ProSchmelz Fluorid Gelée (G5)] in the evening for 30 s. After 20 days, surface profiles were recorded again and enamel loss was determined by comparing them with the baseline profiles. The results were statistically analysed using one-way analysis of variance (ANOVA) followed by Tukey`s HSD post-hoc test.ResultsThe overall highest mean wear of enamel (9.88 ± 1.73 µm) was observed in the control group (G1), where no fluoride gel was applied. It was significantly higher (p < 0.001) compared to all other groups. G2 (5.03 ± 1.43 µm), G3 (5.47 ± 0.63 µm, p = 0.918) and G4 (5.14 ± 0.82 µm, p > 0.999) showed the overall best protection from hydrochloric acid induced erosion. Enamel wear in G5 (6.64 ± 0.86 µm) was significantly higher compared to G2 (p = 0.028) and G4 (p = 0.047).ConclusionsAfter 20 days of daily application, all investigated fluoride gels are able to significantly reduce gastroesophageal reflux induced loss of enamel.

Can the efficacy of in-office tooth bleaching change in the presence of orthodontic brackets? An in vitro study

Objective: To assess the color change of bovine enamel after tooth bleaching while using orthodontic brackets. Methodology: This in vitro study selected 48 bovine incisors without visible fractures or cracks (cut in blocks of 8x12x3 mm). They were distributed in four groups: no staining and with brackets (NSWB), no staining and no brackets (NSNB), with staining and brackets (WSWB), and with staining and no brackets (WSNB) (n=12). The color was initially assessed with a spectrophotometer for NS (no staining). The teeth in WS (with staining) groups were immersed in an instant coffee solution for 15 days and the initial color was also assessed. After prophylaxis and adhesive treatment, the brackets were bonded to the teeth. The teeth were bleached with 35% hydrogen peroxide and the color was analyzed 30 days after bleaching. A two-way Analysis of Variance was applied as well as a subsequent multiple comparison analysis (p&gt;0.05). Results: According to the data obtained, the factor of the presence of brackets (p=0.569) had no significant influence. This differed from the factor of tooth staining (p&lt;0.001). Moreover, there was no interaction between them (p=0.863). Conclusion: The presence of brackets in non-stained teeth did not affect bleaching effectiveness. The ΔE of stained teeth was always lower than non-stained teeth, especially for the NB (no brackets) group.

Bond strength of a universal adhesive system to bovine vs. human primary teeth

To compare the bond strength of a universal adhesive system to bovine primary and human primary enamel and dentin. Flat enamel and dentin surfaces from 28 sound human primary molars and 28 bovine primary incisors were bonded with Scotchbond Universal Adhesive applied in etch-and-rinse and self-etch mode (n = 7). Composite resin cylinders (0.72 mm 2 ) were built on the adhesive area. The specimens were submitted to a microshear bond strength test, and the bond failure mode was evaluated. Bond strength data (MPa) were analyzed using two-way ANOVA and Tukey's test (α = 0.05). Energy-dispersive X-ray spectroscopy (EDS) was carried out to identify the levels of calcium and phosphorus in each type of teeth. Higher bond strength values were found to bovine primary enamel compared to human enamel (p = 0.04). No statistically significant differences were found between bovine and human primary dentin (p = 0.09). The universal adhesive applied in self-etch mode to enamel resulted in lower bond strength values (p < 0.05). EDS analysis showed significantly lower calcium content in bovine primary dentin (p = 0.01), but no significant differences were found between bovine and human primary enamel. Bovine primary teeth can only reliably replace human teeth in bonding studies when dentine is the focused substrate. Bovine primary enamel promotes higher bond strength values compared to human primary enamel.

Modification of the Lipid Profile of the Initial Oral Biofilm In Situ Using Linseed Oil as Mouthwash.

Lipids are of interest for the targeted modification of oral bioadhesion processes. Therefore, the sustainable effects of linseed oil on the composition and ultrastructure of the in situ pellicle were investigated. Unlike saliva, linseed oil contains linolenic acid (18:3), which served as a marker for lipid accumulation. Individual splints with bovine enamel slabs were worn by five subjects. After 1 min of pellicle formation, rinses were performed with linseed oil for 10 min, and the slabs’ oral exposure was continued for up to 2 or 8 h. Gas chromatography coupled with electron impact ionization mass spectrometry (GC-EI/MS) was used to characterize the fatty acid composition of the pellicle samples. Transmission electron microscopy was performed to analyze the ultrastructure. Extensive accumulation of linolenic acid was recorded in the samples of all subjects 2 h after the rinse and considerable amounts persisted after 8 h. The ultrastructure of the 2 h pellicle was less electron-dense and contained lipid vesicles when compared with controls. After 8 h, no apparent ultrastructural effects were visible. Linolenic acid is an excellent marker for the investigation of fatty acid accumulation in the pellicle. New preventive strategies could benefit from the accumulation of lipid components in the pellicle.

Antibacterial and antibiofilm activities of cinnamon essential oil nanoemulsion against multi-species oral biofilms

Cinnamon essential oil (CEO) has antibacterial properties, but its ability to suppress the formation of multi-species oral biofilms has not been fully elucidated. This study evaluated the antibacterial and antibiofilm activities of cinnamon essential oil nanoemulsion (CEON) against oral biofilms formed using a microcosm biofilm model. The biofilms were formed on bovine enamel specimens over a 7-day period, during which all specimens were treated with one of three solutions: 5% CEON (n = 35), 0.5% cocamidopropyl betaine (n = 35), or 0.12% chlorhexidine gluconate (CHX; n = 35). Antibacterial and antibiofilm activities were determined by the red/green ratios (R/G values) of 7-day-old mature biofilms photographed with quantitative light-induced fluorescence-digital, the number of aciduric bacterial colony-forming units (CFUs) within each biofilm, and the absorbance of bacterial suspensions. One-way and repeated-measures analysis of variance were performed to compare differences among the three solutions. R/G values were lowest in the 0.12% CHX group, but not significantly differ from the 5% CEON group. The number of CFUs and absorbance were lowest in the 5% CEON group. This study showed that nanoemulsified CEO inhibited the maturation of multi-species oral biofilms and the growth of oral microorganisms in biofilms, including aciduric bacteria that cause dental caries.

Verification of antibacterial activity to enamel surfaces of new type of surface coating

Abstract Objective Prevention is difficult to decrease dental caries only via the partial application of fluoride. The GC Co. has developed a coating material adhesive containing fluoride and zinc. It is thought that this zinc has an effect which prevents dental caries. The aim of this study was to evaluate the influence of the Caredyne Shield® (CS) on biofilm generation by S. mutans, as compared to an acidulated phosphate fluoride (APF) gel. Materials and methods We performed the comparative study of the biofilm inhibitory effect which used the enamel of bovine teeth. Specimens were separated into a control group, an APF gel group, and a CS group. Biofilms were generated by adherent S. mutans. We observed the antibacterial weigh by the creation state of Biofilms. Results Significant difference was observed in the number of bacterial colonies formed after 24 h, the number of bacterial colonies formed from detached S. mutans from the CS-treated experimental group were fewer in number than in the other group (p Conclusion We showed in this study the efficacy of CS in controlling the formation of biofilm. From such a result, we conclude that CS is a novel anticaries agent.

Effect of Different Dentifrices, Bleaching with 35% Hydrogen Peroxide, and Red Wine on Surface Color and Roughness of Bovine Enamel

Objective: To evaluate color and roughness of bovine enamel exposed to dentifrices, dental bleaching with 35% hydrogen peroxide (HP), and erosion/staining by red wine. Methods: Bovine enamel blocks were exposed to: artificial saliva (control), Oral-B Pro-Health (stannous fluoride with sodium fluoride, SF), Sensodyne Repair &amp; Protect (bioactive glass, BG), Colgate Pro-Relief (arginine and calcium carbonate, AR), or Chitodent (chitosan, CHI). After toothpaste exposure, half (n=12) of the samples were bleached (35% HP), and the other half were not (n=12). The color (CIE L*a* b*, ΔE), surface roughness (Ra), and scanning electron microscopy were evaluated. Color and roughness were assessed at baseline, post-dentifrice and/or -dental bleaching, and after red wine. The data were subjected to analysis of variance (ANOVA) (ΔE) for repeated measures (Ra), followed by Tukey´s test. The L*, a*, and b* values were analyzed by generalized linear models (a=0.05). Results: The HP promoted an increase in Ra values; however, the SF, BG, and AR did not enable this alteration. After red wine, all groups apart from SF (unbleached) showed increases in Ra values; SF and AR promoted decreases in L* values; AR demonstrated higher ΔE values, differing from the control; and CHI decreased the L* variation in the unbleached group. Conclusion: Dentifrices did not interfere with the bleaching efficacy of 35% HP. However, dentifrices acted as a preventive agent against surface alteration from dental bleaching (BG, SF, and AR) or red wine (SF). Dentifrices can decrease (CHI) or increase (AR and SF) staining by red wine.

Evaluation and Comparison of Newly Developed Phosphoric Acid Gel (Exir) with Two Different Common Gels in Iran

Introduction: Different surface treatments were preposed to prepare the tooth structure for resin composite bonding. One of the most common preparation is using of phosphoric acid etching. This study conducted to determine the etching effectiveness of a new formulated acid etchant (Exir) and compared it with two commercial products. Methods: To determine the physical properties, the viscosity and shelf life were evaluated by a viscometer and a centrifuge over the time, respectively. SEM micrographs were uesd to show the geometry of bovine enamel and dentin surfaces which were treated by three etchants. The µSBS of composite to treated dental tissues was also investigated. Data were analyzed by ANOVA and Tukey test (α=0.05). Results: Exir etchant showed the lower viscosity compared with two other gels and two-phase separation did not significantly increase during suggested period. The SEM images of enamel samples treated with Exir etchant showed regular etching patterns and less remnant in comparison with other groups. The SEM mages of dentin samples treated with Exir etchant, unlike others, showed wide open dentin tubules with clear exposed collagen fibers. Enamel and dentin µSBS were 30.08±6.79 and 7.29±1.27 for Exir etchant, 23.31±6.64 and 8.49±3.61 for Morva Etch and 23.22±7.05 and 6.16±1.68 for Ultra-Etch, respectivley. The µSBS values ​​for enamel was significantly higher in Exir treated group (P=0.017), while there was no significant difference in dentin µSBS values among three tested etchants (P=0.07). Conclusion: The results of this study showed Exir etchant can provide acceptable results used on dentin and enamel substrates.