Study protocol for a multi-center, randomized controlled trial to develop Japanese denture adhesive guidelines for patients with complete dentures: the Denture Adhesive Guideline trial: study protocol for a randomized controlled trial.

Suguru Kimoto,Noriyuki Hoshi,Yoshikazu Yoneyama,Masakazu Morokuma,Akito Tsuboi,Tetsuya Suzuki,Shunsuke Minakuchi,Kenichiro Nakai,Toshio Hosoi,Takeshi Maeda,Guang Hong,Hisatomo Kondo,Tadafumi Kurogi,Atsuko Gunji,Masahiro Nishimura,Makiko Saita,Keiko Fujimoto,Yasuhiko Kawai,Gaku Ohwada,Yusuke Sato,Mamoru Murakami,Yasuhiro Nishi,Tetsuo Ichikawa,Hiroshi Murata,Katsuhiko Kimoto,Kazuhiro Yoshida,Tomohiko Murakami,Joji Okazaki,Keisuke Nagao ,Yoshiaki Sato ,Takayoshi Nomura ,Takashi Hamada

doi:10.1186/s13063-016-1612-x

Abstract

BackgroundDenture adhesives, characterized as medical products in 1935 by the American Dental Association, have been considered useful adjuncts for improving denture retention and stability. However, many dentists in Japan are hesitant to acknowledge denture adhesives in daily practice because of the stereotype that dentures should be inherently stable, without the aid of adhesives. The aim of this study is to verify the efficacy of denture adhesives to establish guidelines for Japanese users. The null hypothesis is that the application of denture adhesives, including the cream and powder types, or a control (isotonic sodium chloride solution) would not produce different outcomes nor would they differentially improve the set outcomes between baseline and day 4 post-application.MethodsThis ten-center, randomized controlled trial with parallel groups is ongoing. Three hundred edentulous patients with complete dentures will be allocated to three groups (cream-type adhesive, powder-type adhesive, and control groups). The participants will wear their dentures with the denture adhesive for 4 days, including during eight meals (three breakfasts, two lunches, and three dinners). The baseline measurements and final measurements for the denture adhesives will be performed on the first day and after breakfast on the fourth day. The primary outcome is a general satisfaction rating for the denture. The secondary outcomes are denture satisfaction ratings for various denture functions, occlusal bite force, resistance to dislodgement, masticatory performance, perceived chewing ability, and oral health-related quality of life. Between-subjects comparisons among the three groups and within-subjects comparisons of the pre- and post-intervention measurements will be performed. Furthermore, a multiple regression analysis will be performed. The main analyses will be based on the intention-to-treat principle. A sample size of 100 subjects per group, including an assumed dropout rate of 10 %, will be required to achieve 80 % power with a 5 % alpha level.DiscussionThis randomized clinical trial will provide information about denture adhesives to complete denture wearers, prosthodontic educators, and dentists in Japan. We believe this new evidence on denture adhesive use from Japan will aid dentists in their daily practice even in other countries.Trial registrationClinicalTrials.gov NCT01712802. Registered on 17 October 2012.

Highlights

Denture adhesives, characterized as medical products in 1935 by the American Dental Association, have been considered useful adjuncts for improving denture retention and stability
A sample size of 100 subjects per group, including an assumed dropout rate of 10 %, will be required to achieve 80 % power with a 5 % alpha level. This randomized clinical trial will provide information about denture adhesives to complete denture wearers, prosthodontic educators, and dentists in Japan. We believe this new evidence on denture adhesive use from Japan will aid dentists in their daily practice even in other countries
Japanese dentists tend to prohibit denture wearers from using denture adhesives even though these individuals suffer from unstable dentures; many of these individuals are unable to visit a dental clinic owing to physical disabilities

Summary

Introduction

Denture adhesives, characterized as medical products in 1935 by the American Dental Association, have been considered useful adjuncts for improving denture retention and stability. Many dentists in Japan are hesitant to acknowledge denture adhesives in daily practice because of the stereotype that dentures should be inherently stable, without the aid of adhesives. Denture adhesives, characterized as medical products in 1935 by the American Dental Association Council on Dental Materials, Instruments, and Equipment, have been considered useful adjuncts for improving denture retention and stability. Most dentists in Japan do not acknowledge denture adhesives for several reasons They believe that dentures should be stable inherently, without the aid of products such as denture adhesives. Japanese researchers are hesitant to conduct clinical trials with denture wearers given the negative attitudes regarding denture adhesives. Patients may use dental adhesives at home without understanding their effects, while dentists will not acknowledge denture adhesives without knowing their effects

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