Effect on patient satisfaction of mandibular denture tooth arrangement in the neutral zone

The effect of the neutral zone (NZ) technique on different functional aspects (masticatory performance, speech, and muscle activity) has been studied objectively. Subjectively, some studies reported that their participants felt that NZ dentures were more stable, retentive, and comfortable than conventionally fabricated dentures. These studies, however, lacked a measurable assessment scale or a specifically designed questionnaire.

The purpose of this within-subject, crossover clinical trial was to investigate patient satisfaction levels in edentulous patients after rehabilitation with dentures fabricated using the NZ concept as compared with conventional dentures using a specific, question-oriented patient satisfaction questionnaire.

The clinical trial included 52 participants. Each received one set of conventional dentures and another fabricated based on the NZ concept with a 1-month wash-out period. Participants randomly chose 1 of 2 closed opaque envelopes with 2 denture sequences, either conventional then NZ or NZ then conventional. Hence, participants were blinded to the dentures they wore. Patient satisfaction with each denture type was assessed 6 weeks after insertion by a blinded staff member using a 5-scale questionnaire developed for the most important functional aspects (esthetics, masticatory ability, retention, stability, speech, and comfort). The Wilcoxon Signed Rank test was used to compare the satisfaction scores of the 2 denture types (α=.05).

Patient satisfaction scores were significantly higher with the NZ dentures than with the conventional dentures in all aspects; P=.001 for question 2 (opinion of denture appearance) and P<.001 for all other questions.

NZ dentures offer significantly higher levels of patient satisfaction than conventional dentures in all functional aspects (retention, stability, masticatory ability, and speech) as well as in comfort and appearance.