| Background:Periodontitis is one of the two most common oral diseases in human.According to the third national oral health survey,80%-97%of Chinese adults suffer from varying degrees of periodontal disease.Periodontitis is not only the most widespread chronic infectious diseases in the population,but also the leading cause of the loss of teeth in adults.Because of the close connections between periodontal tissue and pulp tissue in embryonic origin, anatomy and function, the interrelationship of periodontal and endodontic disease has been a subject of speculation for a long time. It is well known that the periodontium communicates with pulp tissues through many channnels or pathways. In addition to the apical foramen, which is the main avenue of communication, the presence of lateral canals has also been established beyond doubt. In a study of1140extracted adult human teeth, lateral canals were found in27%of the teeth. Although communication between pulp and periodontium can be focused on the vascular route, many other possible avenues exist, including nonphysiological pathways and anatomical entities or pathways such as lingual grooves, tooth/root fractures, cemental agenesis/hypoplasia anomalies, intermediate bifurcation ridges, fibrinous communications, and trauma-induced root resorption. The communications mentioned above provide the possibility of interrelationship between these two diseases.Much has been written on the histological condition of the pulp in the presence of periodontal disease. It is generally recognized that pulpal disease could induce or perpetuate (or both) periodontal disease, but the opposite theory is controversial. Although the literature indicates that periodontal disease may have an effect upon the pulp tissue of the involved teeth, no direct relationship between periodontal disease and pulp response has been clearly demonstrated. We found that there is a discrepancy between the opinions of different doctors upon the pathogical changes. Different investigators have listed the histologic changes in the pulp tissues of periodontally involved teeth as varying from normal to necrotic. Some controversy still existed over primary periodontal lesions with secondary endodontic involvement. With the high incidence of periodontitis, whether periodontal diseases can cause the pulp infection or not is of great clinical significance.In1963, Seltzer&Bender examined eighty-five teeth histologically, found that the pulp of only five teeth with periodontal disease were uninvolved, twenty-three teeth were atrophic,forty-two teeth were inflammed, and fifteen teeth were totally necrotic. There observations seemed to indicate that periodontal lesions produce a degenerative effect on the dental pulps of the involved teeth. But Bender reviewed178teeth histologically, and found no relationship between the depth of the periodontal pocket, the extent of bone loss, or the extent of periodontal disease and the degree or extent of pulpal involvement.They deemed that pulp tissue could be affected by periodontal disease, but it did not necessarily follow that, just because periodontal disease exists, the pulp can become involved. Langeland studied sixty teeth with various degrees of periodontal disease histologically and obsevered that pathologic changes occurred in the pulp tissue when periodontal disease was present, but the pulp did not succumb as long as the main canal-the major pathway of circulation was not involved. In addition, if the microvasculature of the apical foramen remained intact, the pulp would maintain its vitality. In addition, some other researchers supported the theory of noncorrelation. In a histologic study of human teeth they demonstrated that pulpal pathosis is irrelevant to the presence or the severity of periodontal disease. Normal pulps were seen in teeth with advanced periodontal disease. Mazur&Massler believed that changes in the pulp are directly related to the patients’systemic condition rather than the status of the periodontium. Periodontal disease does not seem to have much impact on the pulp as few complete pulp necrosis caused by periodontitis can be seen, unless a wide range of channnels or pathways are existed. With the protection of the cementum,pulp necrosis usually does not occur and the pulp will remain active if the micro vascular transport of the apical foramen have not been infringed.Furthermore, a microscopic study of the pulps of human periodontallly diseased teeth following vital root resection revealed no inflammatory alterations, a finding that corroborates the above-mentioned investigators’results. Above all are the main current reseaches on the impact of periodontal disease upon dental pulp tissue. As seen in these studies, it has been understandably difficult to obtain consistency of results and make definitive conclusions on the effect of the periodontal disease upon pulp tissue.Objective:The primary purpose of this study was by observing pulpal pathological changes of different degreess of periodontitis teeth to assess the relationship of the two and to provide some theoretical basis and practical reference for clinical uses,such as the right assessment of the prognosis of the teeth and formulation of appropriate treatment plan, and so on. Methods:1Specimen collectionTwo hundred forty four teeth were collected from one hundred sixty three patients without systemic disease,20to75years of age, diagnosed on the basis of thorough clinical examination and radiographic analysis as having periodontitis. The teeth involved with caries, restorations, attrition, erosion, premature contact, and any obvious clinical symptoms such as pain, acute inflammation, or periodontal abscess were excluded. If, during extraction, any part of the crown or the root fractured, the tooth was omitted from the study. The degree of mobility, the presence of supra-or subgingival calculus, the depth of pockets on the root, attachment loss, and the amount of bone loss were recorded before extraction. Three classes of destruction were derived utilizing the criterion citation from the degree of chronic periodontitis as mild periodontitis group:PD<4mm,AL1-2mm; moderate periodontitis group: PD<6mm, AL3-4mm; severe periodontitis group:PD>6mm, AL>5mm.The normal group using as the pulp tissue observations consisted of54teeth from27patients,9to36years of age,which were selected as the criteria:extraction for orthodontic treatment or impacted,with complete crown and root,without fillings, caries or microcracks.2Specimen processingGeneral Information such as name, gender, age, phone number etc were taken from the patients’records before the dental treatment was started.The teeth concerned were extracted under articaine local anesthesia.Immediately after extraction, the teeth were immersed in10%neutral buffered formalin fixative for3days, and then they were ground flat on selected opposing surfaces under cold water spray until the outline of the pulp could be observed, another3-4days must be re-fixed to allow adequate penetration of the formalin fixative into internal structure. Additionally, both the chronic periodontitis group and the normal group were done by the same approach in order to diminish errors.The teeth were coded and then randomly divided into two different decalcifications. The teeth in thylenediaminetetraacetic acid (EDTA) group were decalcified in EDTA while the teeth in Plank-Rychlo group were decalcified in the other. After complete decalcifications, all the teeth were embedded in paraffin. Step serial sections5microns in thickness were made and stained with hematoxylin and eosin(HE). Three sections were made on each sample. Finally they were examined histologically. It should be noted that the microscopic evaluation of the stained sections were without the knowledge of clinical data.Classification of Pulpal Changes:The morphologic changes observed in the pulp were classified as degree Ⅰ, degree Ⅱ, degreeⅢ, and degreeⅣ.Degree Ⅰ:In the pulp chamber, the multicellular layer of odontoblasts was well preserved, with only occasional vacuoles between the cells. The intercellular ground substance was slightly condensed, with a slight increase in the number of fibrous elements in some pulps. The cells were normal in number and appearance; blood vessels were abnormally prominent; capillaries were abnormally numerous; and venules were abnormally large. Occasionally, small denticles were present.Degree Ⅱ:The odontoblasts were replaced in many areas by vacuoles. There were cysts near and in the pulpal horns. In the root portion of the pulp, hyperemia was pronounced. The fibrous elements of the pulp were significantly increased in number. The fine reticular network of ground substance was more pronounced, and the denticles were more numerous and larger. In the root canal, interstitial calcifications were present.DegreeⅢ:The odontoblasts in the pulp chamber were entirely replaced, in most cases, by vacuoles. The odontoblastic layer was intact in only an occasional specimen. In some areas, reticular degeneration was evident. The cells were pyknotic. The ground substance, especially in the root portion, stained more intensely. Hyperemia was prominent.In the root canal, the pulp contained either vacuoles or cysts and showed reticular degeneration or extensive interstitial calcification.DegreeⅣ:In these specimens, pulpal degeneration was complete; none of the structures were recognizable. In some instances, the entire pulpal chamber and parts of the root canal were filled with calcified masses.3Statistical analysisStatistical analysis of the interrelationship between severity of periodontitis and pathological changes of pulp were conducted by Symmetric Measures, while statistical analysis of pulp pathlogical changes of different degrees periodontitis teeth was applied to Mann-Whitney U rank sum test.Results:1The number of mild periodontitis group, moderate periodontitis group and severe periodontitis group is2,61and184,repectively. Because the number of mild periodontitis group is too small, it is inevitable to combine mild periodontitis group with moderate periodontitis group as mild to moderate periodontitis group. Without pathological changes, five cases of teeth in severe periodontitis group were excluded. The average age of mild to moderate periodontitis group were57.0y, compared with53.8y of severe periodontitis group, while statistical results showing that there was significant difference in age between the mild to moderate periodontitis group and severe periodontitis group. Mild to moderate periodontitis group consists of37male and26female, while severe periodontitis group contains94male and82female. Statistical results showed that there was no significant difference in gender between the mild to moderate periodontitis group and severe periodontitis group.2The average decalcification time of the EDTA group is longer than the Plank-Rychlo group. The staining of the EDTA group is perfect and the pulp structure is intact, with the shape of pulp cells,odontoblasts,blood vessels,nerves and other soft tissue structures seen clearly.The staining of Plank-Rychlo group is slightly inferior to the EDTA group, while pulp cells,odontoblasts, blood vessels,nerves, dentine, predentin and dentine tubules are all visible.3The pathological changes observed in periodontitis teeth are mainly these types:pulp calcification(both pulp stone and diffuse calcification)、fibrosis、vacuolar degeneration of the odontoblastic layer、inflammation reticular atrophy of the pulp、hypereia、necrosis、lateral canals、the secondary dentine and apical forman locatting away from the apex. In mild to moderate periodontitis group, the percentage of both degree I and degree II are28.6%(18/63), while the percentage of degreeⅣ is15.9%(10/63).In severe periodontitis group, the percentage of degreeⅣ is up to40.4%(71/176).while with only8.5%(15/176) of degree I.4Statistical analysis of the interrelationship between severity of periodontitis and pathological changes of pulp was conducted and the value wass0.292, the difference was statistically significant (P=0.000). The results were statistically significant between mild to moderate periodontitis group with severe periodontitis group(Z=4.414,P=0.000)Conclusions:1. There is relative small correlation which can be found between severity of periodontitis and pathological changes of pulp. The more severe periodontitis, the higher the proportion of serious pulp pathosis.2. The pulp of periodontitis teeth may have these pathological changes:pulp calcification-. fibrosis、vacuoles、pulpal inflammation、hyperemia、necrosis, which can exist alone or can be both.But sometimes the pulp may be uninvolved.3. Both EDTA and Plank-Rychlo are very good decalcification solutions, which can make good slices of the pulp tissue. But every coin has two sides. EDTA decalcification solution requires a longer time while the staining of Plank-Rychlo is slightly inferior to EDTA. |
PDF Full Text Request