Effects of Remineralizing Agents Based on Calcium Phosphate, Sodium Phosphate, or Sodium Fluoride on Eroded Cervical Dentin

SUMMARY Objectives: To evaluate the effect of remineralizing agents on collagen matrix pattern, precipitate formation, and dentinal tubule obliteration in eroded cervical dentin. Methods and Materials: One hundred bovine cervical dentin specimens were previously eroded (0.6% hydrochloric acid, pH 2.3, 5 minutes) and then randomized into five groups (n=20): G1, control (without treatment); G2, Desensibilize Nano P (FGM); G3, MI Paste Plus (Recaldent); G4, Regenerate (NR-5); and G5, Desensibilize KF 2% (FGM). These treatments were applied in four sessions with 7-day intervals. During this period, the samples were subjected to an erosive challenge with orange juice (pH 3.8, 5 minutes). The specimens were analyzed by polarized light microscopy with picrosirius red staining, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Results: The G3 showed a higher concentration of type I collagen than G2 and G5 (p<0.05). The G3 showed greater formation of surface precipitates than that of G1 and G5 (p<0.05). In addition, G4 and G5 showed a greater number of open dentinal tubules than that of G3 (p<0.05). Conclusions: Calcium phosphate-based remineralizing agents have shown to be a promising alternative treatment for preventing deleterious effects on the eroded dentin collagen matrix. In addition, they promoted precipitate formation and dentinal tubule obliteration on the eroded dentin.

Effect of eggshell powder application on the shear bond strength of bulk-fill resin composite to bleached enamel

Objective To investigate experimental eggshell powder (ESP) solution application effect on shear bond strength (SBS) test timing of bulk-fill resin composite to bleached enamel. Methods Eighty bovine-extracted anterior teeth were alienated to eight groups (n = 10), representing shear bond strength test timing periods (immediate or delayed) and the remineralizing agents investigated (MI paste Plus and ESP solution). Enamel surfaces were bleached using in-office chemical bleaching agent and the two remineralizing agents were applied then self-etch adhesive and bulk-fill resin composite were performed at 24 h and 14 d before SBS test was done. One-way ANOVA followed by Tukey post hoc test was performed for statistical analysis. Results The control groups showed the highest mean values, while the bleached enamel groups recorded the least mean values. ESP bleached enamel group recorded a significantly higher mean SBS values than MI paste Plus bleached group. Delayed SBS groups showed higher mean values than immediate SBS groups except for control group. Conclusions ESP had a positive and significant effect on SBS of bulk-fill resin composite to bleached enamel surface. Delaying the bonding procedure and restoration of the bleached teeth using resin composite restorations results in a better bond durability.

Efficacy of MI Paste® on Bleaching-Related Sensitivity: Randomized Clinical Trial

Background. To evaluate the effectiveness of MI Paste® in reducing sensitivity associated with vital tooth bleaching. Methods. This randomized controlled split-mouth clinical trial included 45 subjects that were randomly divided into two groups. In Group 1, the maxillary arch was the control arch (only bleaching), while the mandibular arch was the intervention arch (bleaching and MI Paste®). In Group 2, the mandibular arch was the control arch (only bleaching), while the maxillary arch was the intervention arch (bleaching and MI Paste®). Subjects started with the control arch and then switched to the intervention arch after two weeks. Subjects were instructed to use MI Paste® in a custom tray for 5 minutes, wait for 1 hour, and then bleach overnight using a different tray. Sensitivity was measured using both a thermal sensitivity test and a daily log of sensitivity for 14 days. Shade was evaluated using a colorimeter and a shade guide. Results. Immediately after treatment, the thermal test sensitivity scores for the arches bleached without MI Paste® were greater than those with MI Paste® ( p = 0.011 ). Arches not receiving the MI Paste® treatment showed significantly higher VAS sensitivity scores during the 14-day period of bleaching ( p = 0.002 ). The mean score for the 14-day period was 37.9 for the arches not treated with MI Paste® versus 27.5 for the treated arches. Both the intervention group and the control group showed significantly lighter shade relative to baseline ( p < 0.001 ) with no significant difference between them ( p = 0.42 ). Conclusion. MI Paste® significantly reduced the sensitivity associated with bleaching and did not interfere with shade change.

Comparing Enamel Microhardness in Decidous Teeth With Primary Carious Lesions After Applying Three Fluoride Containing Materials in Vitro

Background and Aim: For decades, using fluoride has been introduced to prevent the development and progression of primary carious lesions. Increased surface microhardness of primary caries is among the essential factors in preventing lesion progression and cavity formation. The present study aimed to compare the microhardness changes of primary caries treated with 3 products, containing fluoride (varnish, toothpaste, & mouthwash) in dental teeth. Methods & Materials: In this study, 45 extracted human deciduous molars were used. Using a diamond-winning disc, enamel blocks with a dimension of 1 x 4 x 4 mm were prepared from the buccal surface of the teeth, i.e., healthy and without structural defects; they were mounted in acrylic self-adhesive. Initial microhardness test (Vicker’s test) with a force of 300 gr and Dwell time for 15 seconds was applied on samples. Next, artificial caries with the standard solution were created in all samples and the microhardness of samples was recorded at this stage. The study samples were randomly divided into 3 groups of 15, treated with fluoride varnish, mouthwash, and toothpaste. Then, the microhardness of samples was re-measured. The mean surface microhardness was compared between the study groups by Independent Samples t-test and Bonferroni test. All analyses were performed using SPSS at the significance level of P<0.05. Ethical Considerations: This study was approved by the Ethics Committee of the Arak University of Medical Science (Code: IR.ARAKMU.REC.1397.264). Results: Increase in surface microhardness of primary caries in fluoride varnish group was statistically significant; in GC MI paste plus toothpaste and Oral B mouthwash was non-significant. The research samples treated by fluoride varnish had a higher surface microhardness, compared to toothpaste and mouthwash. Conclusion: According to the present research results, fluoride varnish was superior to fluoride mouthwash and toothpaste in improving the microhardness of primary dental caries.

Efecto de agentes remineralizantes a base de fosfato de calcio sobre la dentina

Objetivos: Evaluar los efectos de agentes remineralizantes a base de fosfato de calcio en la obliteración de túbulos dentinarios y dispersión de energía en la dentina cervical. Material y métodos: Treinta especímenes de dentina cervical bovina fueron previamente erosionados (ácido clorhídrico al 0,6 %, pH 2,3; 5 min) y divididos aleatoriamente en 3 grupos (n = 10): Control – sin tratamiento, NP – Desensibilize Nano P (FGM®) y RD – MI Paste Plus (RecaldentTM). Los tratamientos fueron aplicados en cuatro sesiones con intervalos de 7 días. Los especímenes fueron analizados por microscopia electrónica de barrido (MEB) y espectroscopia de rayos X de energía dispersiva (EDX). Resultados: Los grupos NP e RD mostraron mayor obliteración de túbulos dentinarios que el grupo control (p < 0,05). Las concentraciones de Ca/P fueron similares entre todos los grupos evaluados. Conclusiones: Los agentes remineralizantes a base de fosfato de calcio demostraron ser una alternativa promisoria en la obliteración de túbulos dentinarios.

Effect of Prior Application of Desensitizing Agent on the Teeth Submitted to In-Office Bleaching

This study aimed to quantify the penetration of hydrogen peroxide, color change evaluation, surface morphology, and composition after application of desensitizing agents before in-office bleaching. Fifty premolars were sectioned, an acetate buffer was placed in the pulp chamber and divided into five groups (n=10). In the positive control group, only the in-office bleaching gel was used, and in the negative control group, no treatment was used. Three different desensitizing agents were applied: Desensibilize KF2%® group; Mi Paste® group, and Desensibilize Nano-P® group. The bleaching procedure was carried out with 35% HP. The absorbance of the resulting solution was determined in a spectrophotometer. Color change was assessed by using a digital spectrophotometer. Four additional premolars were assigned to the same groups above for analysis under scanning electron microscope, as well as to evaluate the elemental composition with X-ray dispersive energy spectrometry. Data were subjected to ANOVA and Tukey's test (α=0.05). All products reduced the penetration of HP in the pulp chamber. Mi Paste and Nano P were the products that yielded the lowest HP penetration, which was similar to the negative control group (p<0.001). No significant difference was detected in color change (p<0.001). Concerning enamel morphology, the groups that were analyzed after bleaching were observed a greater deposition of desensitizing agents on the surface. The use of desensitizing agents before tooth bleaching seems to be an alternative to reduce adverse effects of the tooth.

The Effect of the Er:YAG Laser and MI Paste Plus on the Treatment of White Spot Lesions

Introduction: White spot lesions (WSLs) occurring after orthodontic treatment lead to patient dissatisfaction and aesthetic problems. The role of calcium-phosphate demineralization systems and the Er:YAG laser in the treatment of these lesions has recently been taken into account. This study aimed to investigate the effect of the Er:YAG laser and MI Paste Plus on the treatment of WSLs. Methods: A total of 65 premolars extracted due to orthodontic treatment were studied in this research. To create enamel lesions, the teeth were placed in a demineralizing solution. The teeth were then randomly divided into five groups (n=13) as follows: first group, control; second group, saliva; third group, MI Paste Plus; fourth group, Er:YAG laser; and fifth group, MI Paste Plus together with the Er:YAG laser. The teeth were kept in artificial saliva between treatment processes. Artificial saliva was replaced daily with fresh artificial saliva. The teeth were sectioned longitudinally by a disc from the middle of the exposed enamel and each section was mounted in polyester resin. The surface of the samples was serially polished and the microhardness of the teeth was measured at depths of 0, 50, 100, and 150 µm. Results: The microhardness was significantly higher in the fifth group than other groups at depths of 50 and 150 µm (P<0.005). Using the laser or MI Paste Plus alone did not significantly increase the microhardness. Conclusions: The combined application of the Er:YAG laser and MI Paste Plus is effective in the treatment of WSLs.

Antibacterial and Remineralization Efficacy of Casein Phosphopeptide, Glycomacropeptide Nanocomplex, and Probiotics in Experimental Toothpastes: An In Vitro Comparative Study

Objective This article evaluates the antibacterial and remineralization potential of experimentally prepared toothpastes containing different mixtures of nano casein phosphopeptides (nCPP), nano amorphous calcium phosphate (nACP), probiotic ­ Lactobacillus rhamnosus B-445 (L. rhamnosus), and nano glycomacropeptide (nGMP). Materials and Methods Five experimental toothpaste samples were prepared and grouped, such that group (A0) was the experimental toothpaste base formula. Groups (A1), (A2), (A3), and (A4) were the experimental toothpastes containing: nCPP; nCPP and nACP; nCPP, nACP, and L. rhamnosus, and nCPP, nACP, and nGMP, ­respectively. Group (A5) was the commercial group (GC MI Paste Plus). The five groups were screened against Streptococcus mutans (ATCC 25175) growth, and investigated for their remineralizing potentials on demineralized bovine enamel using Vickers ­microhardness test (Vickers hardness number [VHN]). Scanning electron microscope (SEM) images were obtained for the demineralized and remineralized enamel of the two most effective toothpastes against in vitro bacterial induced enamel demineralization. Statistical analysis was performed using one-way analysis of variance (ANOVA) as well as repeated measures ANOVA followed by Tukey’s post hoc test. Results Both (A3) and (A4) were significantly higher in mean inhibition zone ­diameters than group (A1) and (A2). Group (A4) showed the highest statistical ­significance in the mean difference between VHN values of demineralization and 15 days remineralization period. SEM images showed the deposition of nano-sized particles fill the ­microrough surface pattern of the etched enamel. Conclusion All these findings suggest the use of probiotic, nCPP–nACP, and nGMP as a dental anticariogenic and remineralizing active agents.