1. Experimental method There are 5 miniature pigs in China, weighing 14~26kg, 3 males and 2 females. Select the upper and lower first permanent molars and the bilateral mandibular lateral incisors to make a pulpitis model. After miniature pigs are anesthetized with compound bufenac by intramuscular injection of 0.1 ml/kg behind the ears, the mouth and mouth are cleaned thoroughly. 2% iodine tincture disinfects the experimental teeth and periodontal tissues, and prepares holes on the experimental molars with a high-speed turbine crack drill with a perfect cooling device. The mandibular lateral incisors are prepared with Class V holes, and the pulp is carefully penetrated, and the pulp hole is 2 to 3 mm. Wash with normal saline repeatedly to stop bleeding. The control group was capped with calcium hydroxide paste, zinc oxide clove oil paste was used as the bottom, and zinc phosphate cement was used for filling. The experimental group was directly capped with zinc oxide clove oil paste and filled with zinc phosphate cement. Strict aseptic operation during surgery. The animals were sacrificed at 2 weeks, 4 weeks and 3 months after the operation, and the experimental teeth and control teeth were quickly removed, numbered, and fixed with 10% formalin. Histopathological observation: microwave decalcification with hydrochloric acid, formic acid and sodium chloride mixed decalcification solution, gradient alcohol dehydration, serial sections embedded in conventional paraffin, slice thickness 5μm. HE staining, observe under light microscope.
2. Experimental results 2 weeks after the calcium hydroxide pulp capping operation in the control group, a thin layer of dental pulp necrosis was seen below the pulp hole, fibroblasts proliferated underneath, and a small amount of calcified masses were occasionally formed. The intramedullary inflammatory cells infiltrate obviously, and there is a small amount of blood vessel hyperplasia and congestion in the tissue. One month after pulp capping, restorative dentin clumps can be seen, with denser structure, tube-like dentin, with columnar dentin cells around it, but no complete dentin bridge formation, restorative dentin The lower dental pulp is congested with a small amount of inflammatory cells. Three months after pulp capping, a complete restorative dentin bridge was formed, with irregular shape and tube-like dentin, which was tightly integrated with the primary dentin, and the pulp was normal.
In the experimental group, 2 weeks after pulp capping with zinc oxide clove oil paste, inflammatory cells under the perforation hole were infiltrated significantly, blood vessels were dilated, some pulp was necrotic, and no restorative dentin was formed. One month after surgery, a small amount of irregular calcification masses were seen in the pulp cavity, surrounded by dentin-like cells, and no complete dentin bridge was formed. Three months after the operation, the restorative dentin was formed with irregular shape, surrounded by dentin cells, and the perforating pulp hole was not completely closed.