Experimental Study And Clinical Evaluation Of The Effect Of Air Abrasion Technique

Because of the high incidence and harm of dental fear, the painless dental therapy has become a new theme of oral clinic.The advantage of the cavity preparation technique without cut is more and more prominant.Air abrasion system is one of them. But its painless mechanism is still not clear .We studied the clinical effect of moving off teeth decay by air abrasion,and the change of the rigidty tissue and pulp during the cavity preparation. The following lab experiments were undertaken: Experimental researchPart I Observed the changes of tooth with SEM. Results: The cavity is irregular,but more of rigidty tissue is preserved ,and smear layer which was produced by the tchnique of air abrasion is better thin than that from the old drilling.Part n To observe the change of the substance P and pulp Calcitonin Gene-related Peptide immunoreactive firbres in the pulp of rat with the two stimulations which from air abrasion and high speed hand piece byimmunohistochemical method. Result: The two stimulations led to the increase of synthesization of SP and CGRP in the pulp. The depth was 2mm. But the colour of the group of air abrasion was darker than the group of high speed hand piece. So we tended to think that the slighter or even non-pain reaction of the technique of air abrasion might be related to the change of synthesization and release of SP and CGRP in the pulp.Part HI To observe the response of the pulp which was prepared with air abrasion. The samples were stained by HE and were observed under microscope. Result: There was slight hyperemia in the pulp after 24h, and it . returned to normal completely in rat pulp after 7d. When the cavity was prepared by high speed hand piece, there would appear vacuole in the pulp after 24h. And most of the tissues would not come back to normal until 14d, and in some cases the new-formed reparative dentin was observed by that time. Clinical experiments:Part I To observe the feeling of the patients prepared by air abrasion, we selected thirty patients with a total number of sixty-two caries tooth, and we required the patients to describe their feeling with a number between zero and ten. Result: Air abrasion made less pain than high speed hand piece.Part n We counterchecked the patients in one week,, and compared the activity of the pulp with preoperational conditions. Result: There were no difference between two groups, but the pulp energy of the group of high speed hand piece was declining.