@article {103480, title = {THE INFLUENCE OF 532 NANOMETER DIODE LASER ON THE BIOLOGICAL RESPONSE OF DOGS{\textquoteright} DENTAL PULP CAPPED WITH MINERAL TRIOXIDE AGGREGATE}, volume = {60}, year = {2015}, abstract = {

Aim: This study aimed to assess the biological response of dog dental pulp to 532 nanometer (nm) diode laser compared to 0.9\% saline and 2.5 \% sodium hypochlorite (NaOCl) used to control infection and bleeding after being capped with Mineral Trioxide Aggregate (MTA).
Methods: Sixty teeth of six dogs, including anteriors and premolars were used. After general and local anesthesia, class V cavity was prepared and the pulp was exposed. Pulp exposure sites were randomly divided into three equal groups 20 teeth each, according to the method of achieving disinfection and haemostasis; 532 nm diode laser with 1 Watt power and exposure time 30 seconds, 0.9\% saline and 2.5 \% NaOCl. Each group was subdivided into two subgroups according the time of MTA application; 6 and 12 weeks. The exposure sites were then sealed with MTA and restored with composite resin. The animals were sacrificed at 6 and 12 weeks and the teeth were extracted and prepared for haemotaxylen and eosin staining. The pulps of the teeth were examined for the presence of the followings: inflammatory cells, pulp necrosis, pulp calcification, and dentin bridge formation. The number of inflammatory cells and thickness of dentin bridge was measured in ten areas of the histological sections that were randomly chosen for each tooth along the whole length of pulp and the whole length of the dentin bridge at high power field (x200) and the mean value was obtained.
Results: All experimental groups showed chronic inflammatory cells infiltrate with the intensity decrease as time elapsed. Pulp tissue necrosis and calcification weren{\textquoteright}t observed at any teeth. On 6 weeks, 7 teeth in group 1 and 6 teeth in both groups 2 and 3 showed dentin bridge formation. While at 12 weeks, all specimens showed dentin bridge formation which was more continuous and thicker than that observed in the 6 weeks. However, the continuity and thickness were considerably variable between different groups. There was a significant difference in the number of inflammatory cells and dentin bridge thickness between the groups at both observation periods (P <= 0.005). Statistical evaluation of inflammatory response showed that group 1 was significantly different from groups 2 and 3 separately with lower inflammatory cell response (P <= 0.005) and significant differences were detected between the other two groups (P <= 0.005). Significant differences in the thickness of dentin bridge were detected in two -by- two comparison between the three groups with group 1 showed the greater thickness and group 2 demonstrated the lowest thickness (P <= 0.005).

}, author = {Wafaa Ahmed Omar Segari and Latifa M.Abd El Gawad} }