Different Material Removable Partial Denture Wearing A Comparative Study Before And After Voice Effect

Purpose:To study the variation law of acoustic characteristic of removable partial denture in maxillary KennedyⅠdentition of two different materials and explore the thickness of base, the influence on speech of covering place to provide acoustic theoretical basis for the design of maxillary partial denture.Methods:Thirty KennedyⅠdentition patients were selected,including fifteen plastic bases and fifteen metal bases.The computer acoustic analysis system was used to analyze the first two formant(F1,F2) and the first formant band width(BI) of vowels /a/,/i/,/u/,the first two formant(F1,F2) in the area of energy concentration of consonant /t/,/k/,/j/,/z/,/s/,/sh/ before,during,after restoration,and in one week,two weeks,four weeks and eight weeks respectively.Results:(1) It showed no statistical difference between the two groups of vowels /a/,/i/,/u/.(2) About consonant /j/It showed statistical difference(P<0.05) of F2 between during and before restoration;and between two weeks,four weeks,eight weeks and during restoration in plastic base group.It also showed statistical difference(P<0.01) between during and one week after restoration (P<0.05) of F2 compared at the same time between the two groups.About consonant /z/In plastic base group,there were statistical difference of Fl and F2(P<0.05) between before and after two weeks,four weeks,eight weeks restoration.There were statistical difference of Fl(P<0.05) between during and after eight weeks restoration。In metal group,there were statistical difference of F2(P<0.01) between before and after one week restoration and statistical difference of F2(P<0.05) between before and after two weeks,four weeks,eight weeks restoration.When compared between the two groups at the same time,there was statistical difference of F2 about /z/(P<0.05) after one week restoration.About /s/①There were statistical differences of F2(P<0.05) between before and after two weeks, four weeks,eight weeks restoration in plastic base groups.②In metal group,there were statistical differences of F2(P<0.01) between before and after one week restoration.There were statistical differences of F2(P<0.05)between before and after two weeks,four weeks,eight weeks restoration.When compared between the two groups at the same time,there was statistical difference of F2 about /s/(P<0.05) after one week restoration. About /sh/There were statistical differences of F1(P<0.05) during and after two weeks and eight weeks restoration.Conclusions:(1) The thickness of removable partial denture has no influence on vowels while plastic base removable partial denture has influence on consonant /j/,/z/,/s/,/sh/. Metal base removable partial denture has influence on /z/,/s/.(2) The thickness of removable partial denture affects the anterior hard palate most while it has no influence on other parts.In clinic,the recovery of speech function can be speeded up by reducing the thickness of hard palate base.