The Effects Of Removable Restoration For Kennedyâ…¢ Dentition Defect On The Constituent Ratio Of Bacteria In The Subgingival Plaque Of Abutments

Objective: By detecting the periodontal index and the constituent ratio of bacteria in thesubgingival plaque of abutments and control teeth after wearing removable restoration forKennedy Ⅲ, analyze the relationship between removable restoration and abutmentperiodontal tissue and discuss the influence which removable dentures have on abutmentperiodontal tissue, to provide a certain theoretical basis and guiding basis for theprevention and cure of abutments secondary periodontal disease and the periodontalhealthcare as well.Methods:30Kennedy Ⅲ patients, each ofwhom was lack of the first molar, wereselected. Everyone’s second pre-molars on the missing side were regard as experimentalgroup and the ones with the same name on the opposite side as control group. According tofour time periods: before restoration, the first month, the third month and the sixth month,assayed PI of the two groups: plaque index(PLI), gingivitis index(GI), Probing depth(PD),at the same time collect their subgingival plaque samples, Used2%Congo red negativestaining to detect the constituent ratio of coccus (C), fusiform bacillus(Fu) andspirochete(S).Results:1.Clinical periodontal index(1) PLI index: Compared the experimental group with the control group, there was nostatistically significant difference between before restoration and the first month (P>0.05);There were statistically significant differences between before restoration and the third, thesixth month (P<0.05). In the experimental group, there was no statistically significantbetween before restoration and the first month (P>0.05). There were statistically significantbetween before restoration and the third and sixth month (P<0.05). There were greatsignificant differences for the first month comparing to the third and the sixth(P<0.01).There was statistically significant difference between the third and the sixth(P<0.01). (2) GI index: Compared the experimental group with the control group, there was nostatistically significant difference between before restoration and the first month (P>0.05);There were statistically significant differences between before restoration and the third, thesixth month (P<0.05). In the experimental group, there was no statistically significantbetween before restoration and the first month (P>0.05). There were statistically significantbetween before restoration and the third and sixth month (P<0.05). There were greatsignificant differences for the first month comparing to the third and the sixth(P<0.01).There was statistically significant difference between the third and the sixth(P<0.05).(3) PD index：Compared the experimental group with the control group, there wasstatistically significant difference between before preparation and the sixth month (P<0.05)while there were not among the other group(P>0.05), and for the others in the group, no.2.Laboratory tests(1) The comparison between the experimental group and the control group: at four periodson the constituent ratio of subgingival coccus(C), fusiform bacillus(Fu), spirochetes(S):There were no statistically significant differences on C, Fu, S before preparation(P<0.05),while in the first, third and sixth month, there were(P>0.05).(2) Internal comparison: Compared before preparation with the first month, There was nostatistically significant difference on the constituent ratio of C, Fu, S (P>0.05). Comparedbefore preparation with the sixth month, the first with the third, the third with the sixth:there were all distinct differences (P<0.01). Compared before preparation with the thirdmonth, there was no statistically significant difference on the constituent ratio of fusiformbacillus(Fu)(P>0.05), while there was on the constituent ratio of coccus(C) andspirochetes(S)(P<0.05). Compared the first with the third month, there was no statisticallysignificant difference on the constituent ratio of coccus(C) and fusiform bacillus(Fu)(P>0.05),while there was on spirochetes(S)(P<0.05).Conclusion: As to the removable restoration for Kennedy Ⅲdentition defect, before andafter restoration, both its abutment PI and the constituent ratio of C, Fu and S changed. Astime went by, there were obvious differences. The change of the constituent ratio ofbacteria in the subgingival plaque of abutments was earlier than that of the PI in clinics.