Improvement Of Histological Staining In The Study Of Pulp-dentin Complex

The pulp-dentin complex is not only the basic component of the teeth,but also the important structure which enforces the physiological functions of the teeth.Dental pulp diseases are common problems and frequently-occurring diseases in mankind, the processes of their occurrence have more relations with the change of the pulp-dentin complex histostructures.Therefore,more and more studies have been focused on the pulp-dentin complex.Most of the current research techniques are imaged with light microscopy or electron microscopy after tissue staining or angiography.As the dental pulp is surrounded by the hard tissues,it is difficult to observe the three-dimensional shape of it.What's more,in the same individual,the specific distribution and the spatial structure of the three main tissues of the complex-odontoblast cells,nerves and blood vessels are not very clear.Proceeding from the morphological study and getting through the series of experiments,this study employed the methods of Holmes Restoring Silver staining coordinated with the modified Hematoxylin-Eosin(HE) staining and Iodate-Silver-Urotropine(Periodic Aeid-Silver-Methenamine,PASM) staining combined with Hematoxylin-Eosin(HE)staining,the distributions,spatial structures and the relationship among the different histostructures in the pulp-dentin complex were observed by the light microscope,so as to get a consolidated understanding of the main histostructures of the pulp-dentin complex and further enrich the basic theory in morphology of the pulp-dentin complex.Objectives:To explore a better method to study the histological characteristics of the pulp-dentin complex,and deeply understand its internal features of the complicated histostructures,so as to provide a theoretical foundation for clinical endodontic treatment.Methods:Caries-free premolars removed for orthodontic treatment were select, the dentins were exposed after disposing,fixed by 10%formalin,decalcified by 8% nitric acid.After conventional histo-sections,use the methods of Holmes Restoring Silver staining coordinated with the modified Hematoxylin-Eosin(HE) staining and Iodate-Silver-Urotropine(Periodic Aeid-Silver-Methenamine,PASM) staining combined with Hematoxylin-Eosin(HE)staining,the organizational structure of pulp-dentin complex was observed with light microscopy.Results:By the Holmes Restoring Silver staining,the nerve tissue presented in black with light microscopy,the distribution of nerve fibers in dental pulp could be seen all around the small blood vessels and cells.The end of the nerve fibers were uniformly distributed,the thickness were even and the shape were regular.Through the redying with H-E staining,the background was light pink,the directions of the blood vessels could be distinguished and the morphology of the blood cell could be recognized more or less.After redying with the modified PASM staining into HE staining,the background was light pink and the nerve tissue presented in black net-like structure,the spiral nerve fibers penetrated through the odontoblast layer and went into the pre-dentin,there were a certain number of curved nerve fibers in the pre-dentin layer,their distribution was almost the same as the tubules';the vessels and cells of the pulp could also be seen clearly.Conclusions:Through the methods of Holmes Restoring Silver staining coordinated with the modified Hematoxylin-Eosin(HE) staining and Iodate-Silver-Urotropine(Periodic Aeid-Silver-Methenamine,PASM)staining combined with Hematoxylin-Eosin(HE)staining,we can get a clear image of the pulp's multiple structure,such as the microvasculars,the cells and the nerve tissues.Compared with the Holmes Restoring Silver Staining,the modified PASM staining has more specificity in the images of nerve tissues in dentin,it also has more advantages in the application of nerve tissues'staining.But the experimental cost of the Holmes Restoring Silver Staining with the midified HE staining is low.The study proved that both of these two methods can be applied in the histological research of the pulp-dentin complex and each has its own advantages.