The Effects Of Cementum Preservation On The Regeneration Of Periodontal Tissue

Periodontitis is a chronic infectious disease with high incidence. It is one of the important reasons that cause tooth loss. Cementum coveraged on the dental root is hard mineralized connective tissue. In a periodontal initial therapy or periodontal tissue regeneration, cementum was often thoroughly removed in the past few years. However, recent studies show that cementum plays an important role in periodontal tissue regeneration. In periodontal treatment process, whether or not to retain the cementum becomes a research hotspot.ObjectiveTo establish the periodontal bone defect model with beagle dogs. To observe the effects of cementum preservation on the regeneration of periodontal tissue. To provide the evidence for clinical application of this therapy and explore new periodontal therapy concept.MethodsEight healthy adult beagle dogs were selected in this experiment. A U-shaped periodontal osseous defect was created on the buccal of each maxillary canine. Eight dogs were divided into two groups randomly. Cementum was thoroughly removed in one group(control group) while preserved in another group(test group). The dogs were sacrificed in twelve weeks and analyzed by histopathology. The height of defect, the height of new bone(NBH), new bone aera(NBA), the height of new cementum(NCH), new cementum area(NCA) and the amount of new connective tissue(NCT) were measured by Image-Pro-Express system. The results were analyzed by independent samples T test using spss13.0.ResultsAfter surgery, the wound healed well without infection. Twelve weeks later, the color, shape, quality of gingiva and periodontal condition were fine in all groups without root resorption and ankylosis. There were plenty of connective tissue attachment in both experimental group and the control group. However, in the control group, only a small amount of new bone and cementum were found. The height of defect(DH), the height of new bone(NBH), new bone aera(NBA), the height of new cementum(NCH),new cementum area(NCA) and the amout of new connective tissue(NCT) was respectively (4.96±0.25)mm,(0.41±0.05)mm,(0.1197±0.014)mm2,(2.19±0.26)mm,(3.47±0.24)mm2,(5.66±0.25)mm in test group versus (4.95±0.24)mm,(0.11±0.02)mm,(0.0145±0.048)mm2,(1.41±0.26)mm,(1.42±0.22)mm2,(5.48±0.19)mm in control group. Independent samples T test results showed that the difference of NBH, NBA, NCH, NCA was statistically significant between test group and control group. However, there is no statistically significant difference in NCT and DH between the two groups.ConclusionsCementum preservation can promote periodontal tissue regeneration to a certain extent which provides theoretical support for the clinical use.