الفهرس 
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Abstract
Dental caries is a highly common ailment among children worldwide. If left untreated, it can negatively impact various aspects such as chewing ability, speech, appearance, and even the psychological well-being of both the child and the family. Dental caries is recognized as a condition that primarily affects the hard tissues of the teeth, and its development is influenced by a variety of factors. Numerous studies have proved that topical fluoride application was effective for the prevention of caries. However, in the search for alternative materials or complements to fluoride, researchers have turned to the development of bioactive materials that may promote enamel remineralization in a biomimetic way.
Due to the new understanding of caries as a chronic disease ,the current trend in dentistry evolved to shift from reparative to regenerative approach. Self-assembling peptide P11-4 showed promising results in the regenerative biomimetic remineralization of initial carious lesions.
Aim of the study :
The aim of this study was to Assess the efficacy of biomimetic self-assembling peptides P11-4 and sodium fluoride varnish on enamel remineralization and to compare the remineralizing effect of biomimetic self-assembling peptides P11-4 to sodium fluoride varnish using Scanning Electron Microscope Examination (SEM) , Energy Dispersive X-Ray analysis (EDXA) and Polarized light microscope.
Study methodology:
Thirty-five freshly extracted lower first premolars were used in this study. Teeth were equally divided into the following groups:
group I (Control): Intact enamel ,no treatment was applied.
The remaining samples were subjected to demineralization protocol to initiate caries like lesion, After initiation of caries like lesions the samples were subdivided into four equal groups.
group II : (demineralization group) No treatment was applied after creation of the lesion and teeth were examined immediately and used as a base line of the carious lesion.
group III: (artificial saliva group) No treatment was applied after formation of the lesions and teeth were stored in daily renewed artificial saliva for one month till the time of investigation.
group IV: (fluoride group) : Enamelast® was the sodium fluoride varnish used in the current study. After lesion formation teeth were lightly dried and painted with the varnish in a single stroke painting motion. Only one application of fluoride varnish was used for the entire study Then teeth were stored in daily renewed artificial saliva for one month till the time of investigation .
group V: (Self assembling peptide group, Curodont Repair)
The peptide P11-4 was supplied as Curodont powder in glass vials. The Curodont Repair solution was prepared according to the manufacturer’s instructions by reconstitution of each vial with 50 μl of distilled water that equals 0.05 milliliter.Then surfaces were dried and one DROP was immediately applied onto the demineralized enamel surfaces. After the application, the samples were allowed to stand for 5 min (till disappearance) to allow for diffusion and self-assembly.Only one application of Curodont was used for the entire study.Teeth were stored in daily renewed artificial saliva for one month till the time of investigation .
Results:
I-SEM results :
• group I : Showed typical morphology of the enamel surface layer with perikymata grooves and ridges. Enamel rod ends with different diameters were observed. Areas of rodless enamel were seen on the ridges. Microcracks were also detected. Enamel surface showed the typical morphology of enamel rods (prism pattern) with fish scale pattern while other areas showed keyhole pattern.The prism pattern is well defined with regular margins .
• group II : showed intermingled areas of rod and rodless enamel. Irregular enamel surface with scattered porosity were observed. The EREs were less observed with ill-defined boundaries. The prismatic pattern was destructed. Microcracks were also observed. The integrity of the enamel rods was severely affected with extensive pitting and defects of the Rods core were observed . The fish scale prism pattern was also detected in some areas. The prismatic pattern showed irregular ill-defined boundaries of enamel rods and increased interprismatic spaces.
• group III : showed less pronounced porosity and irregularity of enamel surface in some areas of enamel .Demineralization of rod core was still detected in some areas of enamel surface.The prism pattern destruction was less pronounced in some areas. Other areas showed ill-defined boundaries of enamel rods with increased interprismatic spaces .
• group IV : showed aggregation of scattered mineralization deposits(globular masses) of variable sizes over the enamel surface. Partial obliteration of some of the EREs ,some areas still show irregular ill-defined borders of enamel rods.
• group V: showed re-establishment of the normal architecture of enamel, porosity of variable sizes were also detected in some samples. Normal appearance of the fish scale of the prism pattern was observed ,while other areas showed irregular ill-defined borders of enamel rods, no destruction was observed in the rod core .
II-EDXA Statistical Results:
• Calcium: Using one-way ANOVA test there was a significant difference between different groups the highest value was found in Curodont followed by the control group then fluoride and artificial saliva while the lowest value was found in demineralized group.Post hoc pairwise comparisons showed Curodont to have significantly higher value than artificial saliva and demineralized groups (p<0.001). Control group also showed a higher significant value when compared to demineralized and artificial saliva groups.
• Phosphorus: Using one-way ANOVA test there was a significant difference between different groups .The highest value was found in the control group followed by Curodont , then fluoride and artificial saliva while the lowest value was found in the demineralized group.Post hoc pairwise comparisons showed the control group and Curodont to have significantly higher values than the demineralized group (p<0.001). In addition, Artificial saliva and fluoride groups showed significantly higher values when compared to the demineralized group.
• Ca/P: Using one-way ANOVA test there was a significant difference between different groups.The highest value was found in Curodont , followed by fluoride group and artificial saliva while the lowest value was found in the demineralized group .Post hoc pairwise comparisons showed Curodont to have significantly higher value than artificial saliva and demineralized groups (p<0.001).
III- Histological results of polarized light microscope:
• group I : Showed the normal course of enamel rods with alternative Hunter-Schreger Bands (HSBs) reflecting the normal mineralization and birefringence of enamel.
• GroupII : Showed a relatively high degree of positive birefringence with loss of the typical enamel structure within the formed lesion.Using imageJ software average lesion depth 62.88 μm.
• group III : Showed a slight decrease in the extent of the body of the lesion .Using imageJ Software average lesion depth was 49.05 μm.
• group IV : Showed noticeable decrease in the extent of the body of the lesion and noticeable negative birefringence compared with the control group.Using imageJ Software average lesion depth 24.43 μm.
• group V: revealed disappearance of the lesion and re-establishment of typical enamel structure with noticeable negative birefrin