تأثير زمن التخريش بحمض الفوسفور في شدة ارتباط الراتنج المركب مع عاج الأرحاء المؤقتة : دراسة مخبرية

الملخص EN

Background & Objective: The etching primary teeth dentin is more important factors for bonding composit with primary teeth dentin.

objective: The aim of this research is to know the effect of time etching with the phosphoric acid 37% by duration (7 or 15 seconds) for the composite bonding strength with primary molar dentin towards shear strength.

Materials & Methods: The research sample consisted of 30 primary molars.

This sample was divided to two equal groups (15 teeth).The sample was formed a regular smear layer by softening the decollating surface using the glass paper with its softness degrees, and it must be wet continuously with water.

Then the teeth have been put inside acrylic casts, then the dentin in first group has been etched for 15 second,and second group for 7 second.

The bonding substance has been spread.

It has been hardened with white light.

Then the composite resin has been applied inside the Teflon cast to take the shape of resinous buttons on the buccal surface of the primary tooth dentin, then, the shear test has been made.

Results: T-Test has been used in This study, There are no statistic differences in the intermediate of the shear bond strength between the etching group with phosphoric acid during 7 seconds and the etching group with phosphoric acid during 15 seconds.

Conclusion: From the results of this vitro study we can say that the etching of primary dentin for more than 7 seconds doesn't increase bonding to composite resin ,and This matter is considered to be very necessary for the treatment of the children teeth to decrease the treatment time.