Effect of a Nano-hydroxyapatite Toothpaste on Enamel Erosive Lesions of Third Molars Induced by Exposure to Orange Juice.

Objectives: This study aimed to assess the effect of a nano-hydroxyapatite (nano-HA) toothpaste on erosive enamel lesions of third molars induced by exposure to orange juice. Materials and Methods: In this in vitro, experimental study, the microhardness of 24 sound-extracted third molars was measured by a Vickers tester. The teeth were then randomly assigned to three groups (n = 8) of nano-HA toothpaste (Pharmed), 1.23% sodium fluoride gel, and artificial saliva. The teeth were exposed to orange juice for 5 min daily for 7 days and were then exposed to nano-HA toothpaste, fluoride gel, or artificial saliva (depending on their group allocation) for 10 min a day. The microhardness of the teeth was measured again after 7 days. Data were analyzed using paired t-test, analysis of variance, and Bonferroni test (alpha = 0.05). Results: Within-group comparisons showed a significant reduction in microhardness of the teeth after the intervention in artificial saliva (P = 0.000), and fluoride gel (P = 0.002) groups. However, no significant reduction occurred in the microhardness of the nano-HA group, compared with the baseline (P = 0.132). Between-group comparisons revealed no significant difference in the microhardness of the three groups at baseline (P > 0.05). However, after the intervention, the microhardness of the nano-HA group was significantly higher than that of other groups (P < 0.05). However, the difference in secondary microhardness between fluoride gel and artificial saliva groups was not significant (P = 1.00). Conclusion: Pharmed toothpaste containing nano-HA has optimal efficacy for remineralization of enamel erosive lesions induced by exposure to orange juice.

Antibacterial Effects of Different Concentrations of Althaea officinalis Root Extract versus 0.2% Chlorhexidine and Penicillin on Streptococcus mutans and Lactobacillus (In vitro).

AIMS AND OBJECTIVES: The aims of the present study were to determine and compare the effects of different concentrations of Althaea officinalis extract, 0.2% chlorhexidine (CHX), and penicillin on Streptococcus mutans and Lactobacillus acidophilus in vitro. MATERIALS AND METHODS: The laboratory study was done, for a period of 8 weeks. Minimum inhibitory concentration (MIC) in the test tube, minimum bactericidal concentration (MBC) in a plate culture medium, and growth inhibition zone diameter methods were used to compare the antibacterial effects of 0.2% CHX, penicillin, and different concentrations of A. officinalis root extract. The data were analyzed by SPSS version 24 using ANOVA and t-test analysis. RESULTS: The results showed A. officinalis root extract had antibacterial effect, but significant differences were in MIC and MBC against L. acidophilus and S. mutans with penicillin and 0.2% CHX mouthwash. In addition, the mean growth inhibition zones of all the concentrations of the plant extract were less than that of the positive control group (P = 0.001). However, the difference in the maximum growth inhibition zone from that with the negative control group was significant. In addition, the antibacterial effect of the extract increased with an increase in its concentration. The extract exerted a greater antibacterial effect on S. mutans than on L. acidophilus. The plant polyphenols content is 3.7% which is equivalent to 29.93 g/ml. CONCLUSION: The root extract of A. officinalis exhibited antibacterial effects on S. mutans and L. acidophilus, but this effect was less than those of CHX mouthwash and penicillin. The antibacterial effect increased with an increase in the concentration of the extract.

Evaluation of pulpal response of deciduous teeth after direct pulp capping with bioactive glass and mineral trioxide aggregate.

AIM: The aim of this study was to evaluate the pulpal response of primary teeth after direct pulp capping (DPC) with two biocompatible materials namely mineral trioxide aggregate (MTA) and bioactive glass (BAG). SETTINGS AND DESIGN: This study was a randomized clinical trial. MATERIALS AND METHODS: A total of 22 healthy primary canine teeth scheduled for extraction for orthodontic reasons were selected. The teeth were divided into two groups of 11 and underwent DPC. The exposure sites were randomly capped with MTA or BAG in the two groups. After 2 months, the teeth were extracted and prepared for histopathologic evaluation. STATISTICAL ANALYSIS: The data were analyzed using Fisher's exact test. RESULTS: In the BAG group, inflammation was seen in three patients; internal resorption and abscess were not seen at all. In the MTA group, inflammation was seen in one patient and internal resorption and abscess were not seen in any patient. Fisher's exact test showed no significant difference between the two groups (P > 0.05). Dentinal bridge formation was noted in five patients in the BAG group and six patients in the MTA group. No significant difference was observed between the BAG and MTA groups using Chi-square analysis (P = 0.67). CONCLUSION: Based on the results of this study, MTA and BAG can be used for DPC of primary teeth.

Remineralizing Effect of Topical NovaMin and Nano-hydroxyapatite on caries-like Lesions in Primary teeth.

INTRODUCTION: NovaMin is a synthetic mineral compound composed of calcium, sodium, phosphorus, and silica. It releases crystalline hydroxyl-carbonate apatite (HCA), which structurally resembles the minerals naturally found in the teeth. Nano-hydroxyapatite (NHA) is a biocompatible compound with high affinity for tooth enamel. NHA particles morphologically resemble dental enamel apatite crystals. Considering the efficacy of remineralizing agents and the importance of conservative preventive measures, this study aimed to compare the remin-eralizing effects of NovaMin and NHA on caries-like lesions in primary teeth. MATERIALS AND METHODS: This in vitro experimental study was conducted on 30 sound human primary anterior teeth with no cracks or fractures. The surface microhardness (SMH) of each tooth was measured at baseline using a Vickers microhard-ness tester. The teeth were then subjected to remineralization/ demineralization cycles, and artificial caries lesions were created in them. The SMH of each tooth was measured again and the teeth were then randomly treated with toothpastes containing NovaMin or 10% NHA powder for 2 minutes daily for a period of 5 days. The SMH of each was again measured afterward. Data were statistically analyzed using independent t-tests and Mann-Whitney U tests. RESULTS: The mean SMH was found to be higher in the teeth treated with NovaMin toothpaste (422.67 kgf/mm(2)) than in the teeth treated with NHA (384.2 kgf/mm(2)); However, this difference was not statistically significant. CONCLUSION: Both NHA and NovaMin were effective for reminer-alization of caries-like lesions of primary teeth and no significant difference was detected in their efficacy.