Objective: (l)To compare the difference between ultrasonic instruments and traditional slow-speed handpiece in retropreparation(2)to evaluate the ultrasonic instruments effecting on canal isthmus (3)to evaluate the feasibility, advantages and disadvantages of ultrasonic instruments on posterior teeth in root-end preparation.

Comparative study on cleaning effects of different methods on occult blood of surgical instruments in delivery room;

Objective To develop a new scalpel which can be used in flap dissection at breast surgery and to investigate the method by which clinicians could improve the research and development of the new surgical instruments.

The method and effect of strengthening the quality of management for surgical instruments;

Research on geometric dimension on-line detection in surgical instrument

Objective To design a new multifunctional surgical instrument case in order to improve the work efficiency and safety of operation in field battle.

Detection of the cleaning effect of operation instruments by test of occult blood;

Method By cotton swab sampling examination of incision wound of laparoscopic operation patients,a survey of contamination condition of laparoscopic operation instruments was carried out.

Objective:To analyze the difficulty at every segment of supply of operation instrument and the method of response.