Remineralization Of Enamel Caries Research Articles

The effect of Zinc Oxide nanoparticles with sodium fluoride in remineralization of enamel caries

Background: the most prevalent chronic condition in the world is caries; the revolution in minimally invasive dentistry clarified the necessity for clinically effective methods to allow remineralization of newly formed enamel caries, and Nanotechnology provides new approaches. Nano-sized ZnO In addition to the individualized antifungal and antibacterial properties, it has been used in fluoride precipitation from aqueous solutions; it acts as an adsorbent to remove F ions. The study aimed to test the effect of applying Zinc Oxide NP with Sodium Fluoride solution on the microhardness of artificially induced dental caries on the enamel surface compared to Sodium Fluoride alone. Materials and methods: thirteen upper first premolars extracted for orthodontic treatment were used.results: the nanoparticles increase the surface remineralization more than sodium fluoride alone and have more excellent microhardness scores. Conclusion: Using zinc Oxide nanoparticles with sodium fluoride is better than using sodium fluoride alone. Keywords: Dental caries, Noninvasive dentistry, Nanoparticles, Zinc Oxide Nanoparticles, Reminerlization.

Remineralization of enamel caries by an amelogenin-derived peptide and fluoride in vitro.

Dental caries is one of the most common oral diseases in the world. This study was tantamount to investigate the combinatory effects of an amelogenin-derived peptide (called QP5) and fluoride on the remineralization of artificial enamel caries. The peptide QP5 was synthesized and characterized, and the binding capability of the peptide on hydroxyapatite (HA) and demineralized tooth enamel surface was analysed. Then, the mineralization function of the peptide and fluoride was studied through the spontaneous mineralization testing and remineralization on enamel caries in vitro. First, the novel peptide QP5 could bind on the hydroxyapatite and demineralized tooth enamel surfaces. Second, QP5 can transitorily stabilize the formation of amorphous calcium phosphate and direct the transformation into hydroxyapatite crystals alone and in combination with fluoride. In addition, compared to blocks treated by peptide QP5 alone or fluoride, the sample blocks showed significantly higher surface microhardness, lower mineral loss and shallower lesion depth after treatment with a combination of QP5 and fluoride at high or low concentrations. The peptide QP5 could control the crystallization of hydroxyapatite, and combinatory application of peptide QP5 and fluoride had a potential synergistic effect on the remineralization of enamel caries.

Comparative evaluation of the effect of Er:YAG laser and low level laser irradiation combined with CPP-ACPF cream on treatment of enamel caries.

Objectives: This study investigated the effectiveness of low power red and infrared lasers and that of Er:YAG laser, in association with CPP-ACPF cream, on remineralization of white spot lesions. Study Design: Fifty intact premolars were immersed in a demineralization solution for 10 weeks to induce caries like lesions and then were divided into five groups. In group 1, the teeth were covered with a CPP-ACPF cream for 3 minutes and then irradiated with a low power red laser (660 nm, 200 mW) for 1 minute through the cream. In group 2, the treatment was the same as that in group 1, but an infrared laser (810 nm, 200 mW) was employed. The specimens in group 3 were irradiated with an Er:YAG laser (100 mJ, 10 Hz) combined with CPP-ACPF. In group 4, the CPP-ACPF cream was applied for 4 minutes and group 5 was submitted to neither laser nor CPP-ACPF. The micro Vickers hardness was compared at 20, 60 and 100 µ from the enamel surface among the groups. Results: The highest microhardness was observed in the low power red and Er:YAG laser groups and the lowest one belonged to the CPP-ACPF alone and control groups. However, no significant difference was found in microhardness of the experimental groups at any of the evaluation depths (p>0.05). Conclusions: With the laser parameters used in this study, neither the combined application of Er:YAG laser with CPP-ACPF nor the combination of low power lasers with CPP-ACPF provided a significant increase in remineralization of enamel caries. Key words:Low level laser, Er:YAG, laser, enamel caries, CPP-ACP, microhardness, white spot lesion.

Remineralization of Enamel Caries Can Decrease Optical Reflectivity

The remineralization of enamel caries can lead to distinct optical changes within a lesion. We hypothesized that the restoration of mineral volume would result in a measurable decrease in the depth-resolved reflectivity of polarized light from the lesion. To test this hypothesis, we measured optical changes in artificial caries undergoing remineralization as a function of depth, using Polarization-sensitive Optical Coherence Tomography (PS-OCT). Lesions were imaged non-destructively before and after exposure to a remineralization regimen. After imaging, microradiographs of histological thin sections indicated that the significant reflectivity reduction measured by PS-OCT accurately represented the increase in mineral content within a larger repaired surface zone. Mineral volume changes arising from remineralization can be measured on the basis of the optical reflectivity of the lesion.

The internal morphology of surface zones from acid-etched caries-like lesions of enamel: An SEM study

The typical carious lesion of enamel is composed of four distinct histologic zones: 1) the surface zone (SZ), 2) body of the lesion (BL), 3) the dark zone and 4) the translucent zone. This study concerned only the SZ, the most superficial zone of enamel caries. Both the SZ and BL may be viewed when a carious lesion is imbibed in water and examined in polarized light (PL). The SZ has a pore volume of less than 5%; whereas the BL has a pore volume of at least 5%, representing the area of the lesion with the greatest mineral loss. Previous SEM studies have shown few differences between the morphologic characteristics of SZs and sound enamel. Remineralization of enamel caries is possible in vitro, but requires repeated, long exposures to calcifying fluids due to the intact SZ. If the intact SZ could be made slightly porous while maintaining its integrity, remineralization of the underlying BL could be facilitated.

The effect of fluoride in the remineralization of enamel caries and caries-like lesions in vitro.

Remineralization occurs naturally during the formation of a carious lesion in human dental enamel and is seen in the form of two of the four classical histological zones of the lesion. Exposure of small lesions to a synthetic calcifying in vitro results in a significant increase in remineralization of the lesion. The degree of remineralization achieved depends upon the presence of fluoride ions in the calcifying fluid and its degree of supersaturation. It appears that only low levels of fluoride are required to trigger the mechanism of remineralization; raising the fluoride level further does not result in a greater degree of remineralization. The calcium ion concentration of the calcifying fluid is critical with respect to determining which components are supersaturated and which in turn determines the degree of remineralization achieved. With levels of 3.0 mM calcium only the superficial region of the lesion is remineralized whereas with a calcium concentration of 1.0 mM, remineralization occurs in depth. It is hoped that studies on remineralization phenomena will provide further insight into the mechanisms of caries formation and be the basis for a more powerful and effective form of caries prevention.