CLINICAL RESEARCH Effect on patient satisfaction of mandibular denture tooth arrangement in the neutral zone Wafa’a R. Al-Magaleh, BDS, MS, PhD, a Amal A. Swelem, BDS, MS, PhD, b Mohamed H. Abdelnabi, BDS, MS, PhD, c and Abdulbaset Mofadhal, BDS d Despite the growing trend of implant treatment and its proposal as the standard of care for the edentulous popu- lation, conventional complete- denture therapy remains a substantial and a more affordable treatment option for the majority of elderly edentulous patients, 1,2 espe- cially those with low socio- economic status. 1 Although conventional dentures have been an effective treatment option for some patients, they are unsuccessful for others because of poor stability, compromised retention, inad- equate facial support, poor esthetics, inefficient tongue function/posture, poor masti- cation or speech, gagging and general discomfort, or the pa- tient’s inability to adapt. All these factors have been clas- sically related to physiologically inadequate contours or denture base volume and functionally inappropriate positioning of denture teeth. 3 Several approaches to positioning artificial teeth have been advocated, 3 but superiority of one method over others is still controversial. Positioning teeth in the neutral zone (NZ) has been a long-advocated approach. The NZ concept is to position a Assistant Professor, Prosthodontic Department, Faculty of Oral and Dental Medicine, Sana’a University, Sana’a, Yemen; and Member of the Quality Assurance Committee, Faculty of Oral and Dental Medicine, Sana’a University, Sana’a, Yemen. b Associate Professor, Oral and Maxillofacial Prosthodontic Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; and Removable Prosthodontic Department, Faculty of Oral and Dental Medicine, Cairo University, Cairo, Egypt. c Associate Professor, Oral and Maxillofacial Prosthodontic Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; and Removable Prosthodontic Department, Faculty of Dentistry, Minya University, Minya, Egypt. d Demonstrator, Prosthodontic Department, Faculty of Oral and Dental Medicine, Sana’a University, Sana’a, Yemen. ABSTRACT Statement of problem. 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. Purpose. 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. Material and methods. 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 (a=.05). Results. 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. Conclusions. 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. (J Prosthet Dent 2019;121:440-6) 440 THE JOURNAL OF PROSTHETIC DENTISTRY Downloaded for scmh lib (scmhlib1@gmail.com) at Show Chwan Memorial Hospital JC from ClinicalKey.com by Elsevier on March 25, 2019. For personal use only. No other uses without permission. Copyright ©2019. Elsevier Inc. All rights reserved.