Histopathological Differences Of Rat Molar Pulp After Indirect Pulp Capping With Different Pulp-cap

Objective: To explore the differences of dental pulp histopathologicalchange in the rat model of deep caries after indirect pulp capping with UrbicalLC light-cured calcium hydroxide, Adper Easy One， Gluma desensitizerand3M Vitrebond light-cured glass-ionome and further make a reference forchoosing one in clinical deep caries resin bonding repair.Methods: Seventy-two healthy male Wistar rats with an age of5to6months and body weight between250and300g were used for this study.These animals were purchased from the Experimental Animal Center of HebeiMedical University. All rats were without caries or periodontal disease andhoused in specific pathogen free conditions.72rats were randomly dividedinto four groups. The four test groups were as follow:Group A: Urbical LC light-cured calcium hydroxideGroup B:3M Adper Easy One self-etching adhesives systemGroup C: Gluma desensitizerGroup D:3M Vitrebond light-cured glass-ionomeThe rats were fixed in supine position after anesthetized with10%chloralhydrate intraperitoneally (i.p.)(3mL per1kg body weight). Prior to cavitypreparation, the bilateral molar area were cleaned mechanically with a smallbrush, chemically with H2O2solution (30mL/L) and disinfected with ethylalcohol (750mg/L). One side of the upper first molar was selected randomly asthe experimental tooth in each one. Meiso-occlusal cavities were prepared inthe fires upper molar teeth with1/4round bur running at max300,000perminute up to the vicinity of the pulp chamber when the bottom of the cavitiesappeared pink. The cavities were permanent cooling with water spray. Thecavities were rinsed with saline solution and then gently dried with a cottonpellet before being capped with dentin bonding agents. Light20seconds after apply a thin layer of calcium hydroxide in the surface of cavities in group A,then coat corrosion acid binder lasting for20seconds, buff lightly for5seconds, light20seconds, fill the cavities with resin. In group B, coatcorrosion acid binder directly, then fill with resin. In group C, coat corrosionacid binder after using Gluma desensitizer. In group D, coat corrosion acidbinder after using glass ion. The rest steps of group B、C and D are same withgroup A. On day1,7and14, the rats in four groups were sacrificedrespectively. The pathological changes in molar pulp were observed underlight microscopy after HE staining and gram staining.Result: The results showed that shows Gluma desensitizer is best in all offour groups，the difference is statistically significant (P<0.05). There was nostatistically significant difference among other three groups (P＞0.05).Conclusion: Gluma desensitizer is a good material in indirect pulpcapping. It suggests that dentists can choose it when the cavity is closing topulp.