Aya Anwar Alsherif , Dorria Mohammed Elbardisy And Doaa Ameen Taiema,

ABSTRACT
Background: Fluorides Have Been Proved To Be One Of The Most Effective Weapons In Still Limited Arsenal Of Anti Caries Agents In The Last Years However, A Better Remineralizing Agents With No Side Effects Has Been Recently Discovered, Nanohydroxyapatite. Objective: To Investigate And Compare The Remineralizing Effect Of Nano-hydroxyapatite And Acidulated Phosphate Fluoride On Initial Artificial Enamel Lesion By The Aid Of; Polarized Light Microscope (PLM), Scanning Electron Microscope (SEM) And Surface Micro Hardness Analysis.

Materials and Methods: Human Fifty Six Sound Non-carious Upper First Premolars Were Divided Into Four Groups. Group I Contained 10 Specimens, Stored In Artificial Saliva For 10 Days. Group II Contained 10 Specimens Which Were Subjected To Demineralization Then Stored In Artificial Saliva For 10 Days. Group III Contained 18 Specimens Which Were Demineralized, Received 5 Cycles Of A 4 Minute Treatment With APF Gel Then Immersed In Artificial Saliva For 2 Days. This Was Repeated For Ten Days. Group IV Contained 18 Specimens Which Were Demineralized, Treated With 10% Aqueous Slurry Of N-HAp For 10 Minutes Then Immersed In Artificial Saliva For 10 Days. The Specimens Were Then Sectioned And Examined Using PLM, SEM And Surface Micro Hardness Analysis Then Statistical Analysis Was Done To Evaluate The Results For Each Group And Compare Between Group III And IV.

Results: Nanohydroxyapatite Group Produced The Best Remineralizing Effect With A Surface Morphology Closer To That Of The Biologic Enamel, The Increase In Surface Micro Hardness Was Highly Significant In Both Group III And IV (P < 0.001) However, It Was Closer To The Baseline Level In Group IV. Conclusion: The Use Of Biomimetic Nanohydroxyapatite As A Remineralizing Agent Holds Promise As A New Synthetic Enamel Biocompatible Material To Repair Early Carious Lesions.