Clinical Study Of The Fixed Partial Denture Therapy For Patients With Compromised Periodontal Condition

Rencently, the study of the therapeutic effect of fixed partial dentures(FPDs) for the patients with compromised periodontal condition using the abutments with more than1/2and less than2/3alveolar bone loss had been hotspot1-4. But most researchers had accessed the therapeutic effect of FPDs in a subjective way4-7. Even though three-dimensional (3D) finite element analysis (FEA) were used to simulate alveolar bone asorption of different levels to analysis the force burden by abutments1,2, the complicate and changeable mechanical environment in mouth still can’t be reproduced. So in this research, subjects who were suffered from chronic adult periodontitis and already have had systematic periodontal treatment were included. And the subjects have their lower anterior teeth missing and more than1/2and less than2/3alveolar bone loss. The effect of FPDs to the abutments eapecially to the abutments of1/2of the alveolar bone lost were accessed from occlusal function, the periodontal condition, the alveolar bone hight of the abutments, the molecules change in the crevicular and oral health impact profile. And to provide evidence for clinical decision making when facing such cases. Methods:1. The Tekscan Occlusal Diagnostic System III (T-Scan III) were used to help occlusal ajust when the FPDs were inserted. Before prosthodontic treatment, at the time of restoring,1and3month after prosthodontic treatment, the occlusal condition was recorded by T-Scan III. When the occlussion is recording, the subjects were ask to bite at intercuspal position (ICP), and the following parameters were calculated:the occlusal percentage of the anterior teeth and posterior teeth, the number of occlusal contact, the vertical dimension of the center of the biting force (COF) to the X axis and Y axis, the occlusal time and the occlusal time of the target teeth.2. The periodontal index of the target teeth were examined before prosthodontic treatment, at the time of restoring,1and3month after prosthodontic treatment. The periodontal index including probing depth (PD), gingival index (GI), calculus index (CI).3. The hight of the alveolar bone of the target teeth was measured by Computed Radiography(CR) before prosthodontic treatment, at the time of restoring,1and3month after prosthodontic treatment.4. The GCF of the target teeth was collected and IL-1β, RANKL, OPG was determined by enzyme linked immunosorbent assay (ELISA) before prosthodontic treatment, at the time of restoring,1and3month after prosthodontic treatment.5. The participants were accessed by OHIP-14before prosthodontic treatment, at the time of restoring,1and3month after prosthodontic treatment.Results:1. When bite at the ICP, the occlusal percentage of the anterior teeth at the time of restoring,1and3month after prosthodontic treatment was higher than that before prosthodontic treatment (P<0.05), wheras the occlusal percentage of the posterior teeth was lower (P<0.05); There was no significant difference between any two time points after prosthodontic treatment of occlusal percentage (P>0.05); There was no change of the number of occlusal contact before and after prosthodontic treatment (P>0.05); Wheras there was less occlusal contact nunmber at1month after restoring compared to the time of restoring (P<0.05); The vertical dimension of COF to the X axis was significant shorter after restoring than that before restoring (P<0.05), but it increased at1month after restoring (P<0.05) and decreased at3month after restoring (P<0.05); There was no significant difference of the vertical dimension of COF to the Y axis after and before restoring (P>0.05); The OT after restoring was decreased than that before restoring (P<0.05); The OT of the target teeth after restoring was decreased than that before restoring (P<0.05), and it was significantly increased at1and3month after restoring than that at the time of restoring (P<O.05).2. No significant different was found before restoring and after restoring in terms of PD, CI, GI of the target teeth (P>0.05).3. As to the alvealor bone hight of target teeth, there were still no significant difference existed throughout the experimental period at all times (P>0.05).4. The concentration of IL-1β and RANKL in the GCF was decreased as the change of time (P<0.05). However, the concentration of OPG postrestoration was increasing throughout the experimental period (P<0.05). The ratio of the concentration of RANKL to that of OPG was significant lower(P<0.05) as the time goes on.5. A significant decrease (p<0.05) in the total and the subscale scores of OHIP-14at3month after restoration compared with pre-restoration. A significance difference (P<0.05) was found in physical pain, psychological discomfort, phychological disability at1month postorestoration than that pre-restoration.Conclusions:For the patients with abutments with more than1/2and less than2/3alveolar bone loss all the clinical indexes may remain stable in short period after FPDs therapy if they receive systematic periodontal therapy before.