Histological Assessment for Healing of Intraoral Surgical Wounds Produced by Diode Laser 940 nm Versus Surgical Scalpel Blade ( An in Vivo study ) ISSN : 1812 – 1217

Aims: The objectives of this study were to compare the wounds healing between two different surgical procedures and to evaluate the efficiency of the diode laser on wound healing after intra-oral incision. Materials and Methods: Experimental study were done on 16 New Zealand rabbits. Two types of wound incision were made in buccal mucosa of each group, each incision was made by using stainless steel scalpel blade NO.15 and other was made by Epic X diode laser. Two rabbits sacrificed of each group at 1 st ,3 rd ,7 th and 14 th days after procedures. Results: The histological findings of this study revealed that there was a significant difference for inflammatory cell infiltration in 1 st ,3 rd , 7 th days in two groups, while there was no significant difference at 14 th days period. Granulation tissue formation appeared higher in diode group , while scalpel showed less amount of granulation tissue formation . In re-epithelialization of present study at 1 st day all section showed nil scores, re-epithelization of oral mucosa appeared significant difference after three days ,and significant difference also at 7 th day between diode and scalpel , no significance differences at 14 days in two groups. Conclusions: Diode laser has many advantages for use particularly in oral surgery , due to a better hemostatic ability, but more tissue damage occurs and more inflammatory cell infiltration in site of incision if compared with group that used of surgical scalpel blade.

Histological Assessment for Healing of Intraoral Surgical Wounds Produced by Diode Laser 940 nm Versus Surgical Scalpel Blade (An in Vivo study)

INTRODUCTION
Wound can be defined as an abnormal condition of cellular structure or function of the human body, wound occurred due to the external injury with or without disruption of connective tissue (1) . The healing process of wound is a complicated pathophysiological mechanism that contains inflammatory and proliferative events (2) .
Surgical scalpels are major tools to make surgical incision (3) . The negative effects of using scalpel blade are bleeding, pain, especially in highly vascular oral lesion and in a patient complaint of bleeding diseases (4) .
Laser units are the alternative to surgical blade on surgeries involving hard and soft operations (5) .
Laser is classified into a different type according to he material of active medium that made from. Within he diode laser, he active medium that used is a semi-conductor type in which a diode pumped directly with electrical current to create a laser beam, diode laser energy can cut soft tissue (6) . The performance of he laser is based on peak absorption rates of each laser wavelength. Certain wavelengths of he laser like Diode laser have an affinity for red pigmented structures, which makes hem particularly effective for soft tissue surgery (7) .
Diode laser wavelengths ranging from 635nm (red region of he visible spectrum) to 980 nm (infrared portion of he light spectrum) (8) . was used.

Histological analysis
After euthanasia was confirmed , the tissue in the area of incision was immediately  (Tables 1, 2 and 3). 2 Mild When inflammatory cells present iո few numbers, less than ½ of the field (X10). 3 Moderate inflammatory cells could be seen iո more than ½ of the field (X10). 4 Severe or abundant when inflammatory cells present in huge numbers, more than ¾ of the field (X10).  Re-epithelization at the edge of the wound. 1 Re-epithelization covering less than half of the wound. 2 Re-epithelization covering more than half of the wound. 3 Re-epithelization covering the entire wound, irregular thickness 4 Re-epithelization covering the entire wound, normal thickness.
These slides sections obtain from mesial, middle and distal region of 1 cm incision in order to exam complete sits of incision.

Statistical analysis
The study used non-parametric u-test (Mann-Whitney), because its comparative study between two groups and data not followed specific disruption.

RESULTS
All rabbits tolerated this procedure well and recovered after surgery without any serious complications.

At The First Day
At 24 hours the inflammatory cells infiltration showed the mean of scores were high in both groups ( Figure.1 , Table 4 and Table 5). Granulation tissue formation was recorded low at first day in scalpel and diode groups ( Figure.2 , Table 4 and Table 5 Table 4 and Table 5). Depending on histometric analysis, re-epithelization of the wound at 3rd day seem the diode and scalpel showed close records in two groups, that are the re-epithelialization only on the edges of the wound ( Figures .3, 6,and 7).  with scalpel incision (Figures 3, 8, and 9).     (5,7,13) .