The purpose of this study was to investigate whether resilient denture liners has the potential to decrease problems affecting the alveolar ridge mucosa during the first adjustment session following the initial fitting of the denture. Interventions were complete denture treatment with permanent acrylic resilient denture liner dentures (RLD) in mandibles and conventional heat-activated acrylic resin dentures (ARD) in mandibles. Maxillary dentures were fabricated with conventional heat-activated ARD. Seventy-four subjects were randomly allocated to the RLD and ARD groups by random permuted blocks within the strata method after obtaining written informed consent. A randomized controlled parallel clinical trial with two hospital centres was conducted from April 2004 to July 2006. The problems were comprehensively evaluated by three outcomes with subjective and objective factors as follows: (i) numbers of sore spots, (ii) duration of wearing dentures and (iii) pain perception with 100 mm Visual Analog Scale. The numbers of sore spots in the mandibular support and border areas for the RLD group were significantly less than those for the ARD groups (P < 0.05). The RLD wearers were able to wear their dentures an additional day longer than the ARD wearers (P < 0.05). The maxillary and mandibular pain ratings for the RLD group were significantly lower than those for the ARD group (P < 0.05). Application of resilient denture liners to mandibular complete dentures provided edentulous patients with fewer problems affecting the alveolar during the first adjustment session following the initial fitting of the denture when compared with conventional denture treatments.