Evaluation of superficial microhardness in dental enamel with different eruptive ages

Abstract

This study evaluated the superficial microhardness of enamel in teeth at different posteruptive ages (before eruption in the oral cavity, 2-3 years after eruption, 4-10 years after eruption and more than 10 years after eruption). The study sample was composed of 134 specimens of human enamel. One fragment of each tooth was obtained from the flattest central portion of the crown to produce specimens with 3 x 3 mm. The enamel blocks were minimally flattened out and polished in order to obtain a flat surface parallel to the base, which is fundamental for microhardness testing. Microhardness was measured with a microhardness tester and a Knoop diamond indenter, under a static load of 25 g applied for 5 seconds. Comparison between the superficial microhardness obtained for the different groups was performed by analysis of Student's t test. The results demonstrated that superficial microhardness values have a tendency to increase over the years, with statistically significant difference only between unerupted enamel and that with more than 10 years after eruption. According to the present conditions and methodology, it was concluded that there were differences between the superficial micro-hardness of specimens at different eruptive ages, revealing an increasing mineralization. However, this difference was significant only between unerupted specimens and those with more than 10 years after eruption.

Cross-Sectional Hardness of Enamel from Human Teeth at Different Posteruptive Ages

“…The higher caries susceptibility of younger teeth has been confirmed by experiments in which artificial enamel caries lesions were produced in extracted teeth at different posteruptive ages [Kidd et al, 1984;Kotsanos and Darling, 1991;Palti et al, 2008].…”

“…Palti et al [2008] evaluated the surface and cross-sectional hardness (CSH) of polished and demineralized enamel at different posteruptive ages. They showed significant differences only between unerupted teeth and teeth exposed for more than 10 years in the oral cavity [Palti et al, 2008]. However, the interpretation of enamel maturation in this study should be done carefully since the samples were polished and demineralized.…”

Kekerasan mikro enamel gigi permanen muda setelah aplikasi bahan pemutih gigi dan pasta remineralisasi (Enamel micro hardness of young permanent tooth after bleaching and remineralization paste application)

“…Terjadi penurunan kekerasan permukaan enamel gigi permanen muda, hal ini menunjukkan bahwa terapi pemutihan gigi menyebabkan perubahan struktur enamel gigi dan menyebabkan terjadinya kehilangan jaringan keras gigi, karena pada enamel gigi permanen muda lebih porous, memiliki kandungan apatit karbonat yang lebih besar, dan memiliki komposisi mineral yang tidak murni yang menyebabkan kristal enamel lebih mudah larut pada keadaan demineralisasi. 8 Penelitian yang dilakukan oleh Potocnik et al, 12 terhadap bahan pemutih gigi menunjukkan bahwa terdapat perubahan pada struktur gigi menyerupai dengan terjadinya initial caries. Menurut Hegedus et al, 13 bahan pemutih gigi yang mengandung peroxida menyebabkan terjadinya perubahan pada struktur organik enamel, tidak hanya pada permukaan enamel tetapi juga pada struktur bagian dalam pada enamel, hal ini disebabkan karena hidrogen peroxida memiliki berat molekul yang ringan.…”

“…Enamel gigi permanen muda lebih porous, memiliki kandungan apatit karbonat yang lebih besar, dan memiliki komposisi mineral yang tidak murni yang menyebabkan kristal enamel lebih mudah larut pada keadaan demineralisasi. 8 Chen et al 7 menunjukkan bahwa efek samping yang ditimbulkan oleh bahan bleaching dapat dihindari dengan beberapa cara, salah satunya adalah dengan memodifikasi bahan bleaching dengan pemberian kandungan fluoride dan air pada bahan serta aplikasi bahan yang dapat mendorong terjadinya remineralisasi. Remineralisasi merupakan proses pengembalian mineral yang hilang dari gigi akibat proses demineralisasi, remineralisasi pada gigi membutuhkan mineral kalsium, fosfat dan fluoride.…”

Comparative Analysis of Remineralizing Potential of Three Commercially Available Agents- An in Vitro Study

“…After the eruption of teeth, enamel undergoes post-eruptive maturation, which is characterized by multiple demineralization -remineralization cycles 1 . A shift in the normal equilibrium conditions towards demineralization for longer period of time results in white spots-the earliest clinical manifestation of a carious process 2 .…”