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العنوان
cmparative Study of Diode Laser
Enhanced Remineralization by
Fluoride and Nanohydroxyapatite of
the Demineralized Human Ename /
المؤلف
Abdallah, Hanan Mansour.
هيئة الاعداد
باحث / حنان منصور عبدالله
مشرف / ريهام مجدي أمين
مشرف / خالد السيد نور الحداد
مناقش / خالد السيد نور الحداد
تاريخ النشر
2021.
عدد الصفحات
152 P.:
اللغة
الإنجليزية
الدرجة
الدكتوراه
التخصص
Dentistry (miscellaneous)
تاريخ الإجازة
1/1/2021
مكان الإجازة
جامعة عين شمس - كلية طب الأسنان - قسم بيولوجيا الفم
الفهرس
Only 14 pages are availabe for public view

from 152

from 152

Abstract

SUMMARY
Introduction:
Enamel demineralization occurs by acid attack during dental caries. The incipient caries lesions could be arrested by the enhancement of remineralization through application of remineralizing agents. The reason for the initial caries is that the organic acids produced by the bacteria have leached out a certain amount of calcium and phosphate ions. Therefore, the increase of calcium or fluoride concentrations in the oral fluids was found to enhance lesion remineralization.
Diode laser has an ability to enhance tooth remineralization, and appears to be a tempting alternative to high power lasers in caries inhibition because of its low energy level which preserves the enamel integrity and minimize the creation of porosities on the tooth surface.
Although fluoride therapy has been the cornerstone of caries-prevention strategies since the introduction of water fluoridation schemes over 5 decades, but it has many drawbacks. Therefore, the introduction of nano sized hydroxyapatite has been used as remineralizing agent. Nano sized particles have similarity to the apatite crystals in morphology and crystal structure. The majority of studies of nanohydroxyapatite in caries prevention have focused on its remineralizing ability.
Accordingly, the aim of this study is to compare between fluoride and nanohydroxyapatite paste on diode laser enhanced remineralization on demineralized human enamel.
Materials and Methods:
Twenty extracted sound human premolars were collected and examined to exclude the affected teeth. There was standardization through the use of the same tooth to be investigated before demineralization (group I), after demineralization (group II) and after treatment (group III). The groups and subgroups are summarized in table (12).
Table (13): Showing summary of the experiment grouping.
Groups Treatment Duration
group I No treatment No treatment
group II 1.0 mol/L HCL 5 minutes
group III Subroup IIIA Demineralized specimens received diode laser 980nm then Sensodyne fluoride toothpaste. Laser: 30 seconds
Fluoride: 140 seconds
Subroup IIIB Demineralized specimens received diode laser 980 nm & Biorepair n-Hap toothpaste. Laser: 30 seconds
n-Hap: 140 seconds
Four mm² window was marked on the middle third of the buccal surface of each premolar. Teeth were coated with acid resistant red nail varnish, leaving the middle third of the buccal surface of enamel exposed to the specified treatment as per the group and subgroup.
Sample evaluation was done regarding enamel surface topography using environmental scanning electron microscope, enamel surface mineral content using energy dispersive X-ray analyzer (EDXA), and enamel microhardness using Vicker’s microhardness tester.
Results:
1- Results of enamel surface topography:
Scanning electron microscopic examination of the control group (group I) has revealed relatively smooth enamel surface free of erosive lesions or porosity with circumferentially horizontal lines on relatively equal intervals (perikymata) and enamel rod ends could be observed in certain regions.
SEM examination of demineralization group (group II) revealed different forms of erosion with displayed scattered porosity all over the enamel surface with separate areas of corrosive changes including crater shaped cavities, linear depressions and fish scale depressions. Furthermore, several regions of the enamel surface showed erosive defects with variables sizes which led to the appearance of rough enamel surface and scattered pits, short cracks and ill-defined perikymata. Fish scale pattern with core defects in the exposed enamel rods were observed, in addition to eroded enamel rod cores with some regions of fused affected rods
Scanning electron microscopic examination of subgroup (subgroup IIIA) has shown patterns of remineralized enamel surface, however, areas of erosive defects were still obvious represented as alternating linear pattern of eroded enamel rods (prismatic enamel) with other remaining affected enamel rods and linear fissure like depressions. Other samples showed typical honeycomb structure denoting eroded prismatic enamel core and protruded interprismatic enamel, and other areas with deeply eroded interprismatic enamel and crater like depressions.
Also, heterogenous enamel surface response including linear pattern of enamel rods obliteration, regions with remaining affected enamel rods and few regions with hyaline enamel defects. Furthermore, fish scale pattern with few partially core-deficient enamel rods were obvious, in addition to areas of affected rods comparable to group II (demineralization), wide erosive defects, and areas of calcified enamel rods were observed. Moreover, occluded calcified enamel rods in most of the surface and few rods with depressed cores.
Scanning electron microscopic examination of subgroup IIIB has revealed smooth enamel surface in most of the regions with perikymata. Some shallow minute erosive spots with no cavitation. Remineralization forms appeared as outer smooth calcification indicating obliteration of the enamel cores accompanied with regions of spotty enamel defects, also calcific precipitates accumulation alternative with areas of porous enamel and few areas showing fish scale appearance. Precipitates in the inter rod substance was presented as white enamel rods with a dark enamel rod core, in addition to hyper calcified boundaries and the core with minimal defects.
2-Results of Enamel surface mineral content:
The analysis of the surface enamel using EDXA has shown the highest surface calcium wt % in group I followed by subgroup IIIB and the subgroup IIIA respectively. The least value was that of group II. The difference between groups and subgroups was statistically significant and the comparison between each two groups/subgroups individually revealed that the difference is statistically significant between two pairs of groups (group II versus group I and subgroup IIIB versus group II).
The analysis of the surface enamel P wt % using EDXA has shown the same order of the tested groups in a descending manner (group I, group IIIB, group IIIA and group II) respectively with a statistically non-significant difference between groups and subgroups and the comparison between each two groups/subgroups individually revealed that the differences between all pairs were statistically non-significant.
The Ca/P ratio of the tested groups showed that group I and subgroup IIIB had almost similar mean values. While the mean values of group II and subgroup IIIA were equal. The difference was statistically non-significant difference between groups and subgroups.
3-Results of enamel surface microhardness:
The measurement of the surface enamel microhardness using Vicker’s Hardness Tester has shown the descending sequence of the tested groups and subgroups as follows: Control, fluoride, nanohydroxyapatite and demineralizing group respectively with a statistically significant difference between groups and subgroups and the comparison between each two groups/subgroups individually revealed that the difference is statistically significant between all groups except two pairs (group I versus subgroup IIIA and Subgroup IIIA versus subgroup IIIB) which showed non-significant difference.
The findings of this study suggest that the use of nanohydroxyapatite paste and fluoride paste application on enamel induced by diode laser showed improved remineralizing effects in the calcium content and microhardness. However, diode laser (low energy laser) enhanced remineralization with nanohydroxyapatite showed more beneficial effect compared to diode laser enhanced remineralization with fluoride regarding the calcium content in the enamel.
There was an increase in the microhardness of the specimens treated with diode laser combined with fluoride and nanohydroxyapatite. However, there was slight increase in the microhardness of the specimens treated with diode laser and fluoride than the specimens treated with diode laser combined with nanohydroxyapatite.