OBJECTIVETo compare the phonetic parameters changes of titanium denture base materials to that of conventionally processed poly methyl methacrylate (PMMA) resin.

METHODSForty-two edentulous patients were included in this study. Each patient received two sets of dentures. One of the upper denture was restored with titanium denture base, the other was restored with conventional PMMA denture base. Consonant /x, sh, r, zh, ch, j, q/ associated with place of articulation and manner of articulation were chosen and all of the processed acoustic specimens were stored at computerized speech lab (CSL). Model 4150 (KAY) for the first concentrated frequency area (CFA-1), voice onset time (VOT) and spectrogram were analyzed.

RESULTSThe consonant articulation effect of denture base showed significant difference between the two type of dentures in the CSL. The consonant parameters (/x, sh, r, zh, ch, j, q/) CFA-1 of group A [(3595 +/- 102), (3089 +/- 104), (1876 +/- 116), (4078 +/- 116), (3604 +/- 119), (5432 +/- 118), (4934 +/- 121) Hz] was different from the one of group B [(3644 +/- 101), (3280 +/- 88), (1978 +/- 113), (4214 +/- 193), (3817 +/- 49), (5478 +/- 158), (5020 +/- 183) Hz] (P < 0.05). The consonant parameters VOT of /zh, ch, j/ in group A [(54.67 +/- 1.13), (143.80 +/- 2.24), (62.53 +/- 0.75) ms] was different from those of group B [(52.88 +/- 0.34), (137.55 +/- 2.50), (62.00 +/- 1.54) ms] (P < 0.05). The consonant parameters VOT of /g, k/ in group A [(26.94 +/- 0.33), (114.53 +/- 2.15) ms] was different from those of group B [(28.59 +/- 0.65), (124.40 +/- 3.74) ms] (P < 0.05). A redundant spike as it was located prior to the inherent spike could be observed in the /g, k/ spectrogram of the PMMA denture base group.

CONCLUSIONSTitanium denture base is recommended to provide a satisfying form of articulate position with thinner front palate thickness of the denture base. CFA-1 and VOT based CSL are effective acoustic parameters for articulation testing after denture delivery.