Acoustic speech analysis of CAD/CAM and conventional Kennedy class IV removable partial dentures

Background/aim Phonetics is an important function of the oral cavity that can be affected by partial or total loss of teeth. This study aimed to examine the influence of the partial denture’s construction technique (conventional and CAD/CAM) on speech quality through acoustic analysis of sound production of letters S, Sh, T, and D using sound analysis software. Patients and methods The study was conducted on 20 patients aged from 25 to 50 years having maxillary anterior teeth loss (Kennedy class IV classification). The patients were randomly categorized into two groups: group I received conventional removable partial dentures (RPDs), while group II received CAD/CAM RPDs. Acoustic speech analysis of the selected letters (S, Sh, T, and D) of the delivered RPDs was assessed and analyzed using ANSYS sound software and SIL speech Analyzer, 1 and 3 months after denture insertion. Statistical analysis was carried out using paired t test and independent t test. Results Group II showed significant difference (P<0.05) in the acoustic pronunciation of the selected letters, in the follow-up period from denture insertion to 1 month after, while for the follow-up period from denture insertion to 3 months there was insignificant difference (P>0.05) in the acoustic pronunciation of the S, Sh, and T sound compared to group I. Within group I and group II separately, they revealed significant difference for all the measured parameters except for VOT/(D) which was insignificantly different. Conclusion RPDs constructed by CAD/CAM technology have a more precise fit of the chrome–cobalt framework with a high quality of sound production even at the time of denture insertion.