The use of laser in the treatment of soft tissue minimizes hemorrhage, provides better view of the operating field, and thereby minimizes operating time. Also, there will be far less post-operative swelling, pain and scar formation, and sterilizing effect are shown in some portions of the wound site. All these advantages of laser therapy contribute to its widespread use in the field of medicine and dentistry. Regarding such facts, we used CO2 laser of different watts in gingivectomy for white rats to compare initial healing process. For the control group, the least amount of output in performing gingivectomy(4watts) was offered, and for the experimental group, 6watts was given. Animals were sacrificed on the second, third days, 1 weeks, 2 weeks, and 3 weeks after operation, and their specimens were histologically analyzed.

The following results were obtained:

Blood clot of small size was observed in both the control and experimental groups after two days, and no more thereafter.

In both the control and experimental groups, the inflammation zone size was the greatest after two days, and it decreased gradually to become almost invisble by the second week. The experimental group showed larger size of inflammation zone during second and third days; however, there was no difference after one week.

Granulation tissue in both the control and experimental groups showed gradual maturation with time, and by the second week, it was almost replaced by normal connective tissue. By the third week, complete healing pattern was observed. The experimental group showed larger granulation tissue than the control group until the third day, but there was no significant difference after one week.

In both the control and experimental groups, gingival epithelialization began on the second day. After one week, regeneration of rete peg and partial formation of junctional epithelium were observed; by the second week, keratinization of oral sulcular epithelium began, and it was completed by the third week.