No abstract

The aim of this study was to determine the effects of an acrylic-based resilient liner (ARL) on masticatory ability by verifying the null hypothesis that masticatory performance and mandibular movements do not differ between people who wear mandibular complete dentures with ARL and those who wear complete dentures with conventional acrylic resin (CAR). From April 2004 to July 2006, we conducted a randomized controlled trial study at two centres. After written informed consent was obtained from 74 edentulous patients, they were randomly allocated to either the ARL group or CAR group. Masticatory performance and mandibular movement at the lower incisal point during chewing were measured as the outcomes. We did not observe significant differences in both outcomes between the groups. The chewing cycles were significantly different during the initial, middle, and final phases of mastication. Within the limitations of the current study, the results indicate that the acrylic-based resilient denture liners used have no clinical impact on the masticatory ability of complete denture wearers.

The results indicate that the LO occlusal scheme with hard resin artificial teeth is more efficient for patients with severely resorbed mandibular ridges.

From this study, the following conclusions were made: (1) OMFT significantly increases LCF; and (2) the AHI and SpO2 during sleep are significantly improved after OMFT.

There have been many reports on fatal distortion of heat-activated acrylic denture-base resin which is still widely used in the field of removable prosthodontics. However, these reports have failed to report quantitatively on polymerization and thermal shrinkage factors. In the present study, we attempted to verify that the shrinkage of heat-activated acrylic denture-base resin was caused mainly by thermal contraction after processing. Furthermore, we examined the degree of distortion resulting from long, low-temperature processing, and compared the results with that of the conventional method. The strain gauge and thermo-couple were embedded in a specimen at the time of resin packing. The measurement started from the beginning of processing and continued until the specimen was bench-cooled and immediately before and after it was de-flasked, as well as during seven-day immersion in water at 37 degrees C. The resin expanded when processed by the conventional method. Meanwhile, mild shrinkage, possibly polymerization shrinkage, was observed when the resin was processed by the low-temperature method. This suggested that polymerization shrinkage was compensated for by thermal expansion during processing by the conventional method. Moreover, the shrinkage strains in the period from the completion of processing to immediately after de-flasking, in both the conventional and low-temperature methods, were identical to the theoretical value of thermal shrinkage which we obtained by multiplying the linear coefficients of thermal expansion by temperature differences. The shrinkage strain in the specimen processed by the low-temperature method, measured from the end of processing to immediately after de-flasking, averaged 64% of that in the specimen processed by the conventional method. The results revealed quantitatively that the shrinkage of heat-activated acrylic denture-base resin was mainly thermal shrinkage, and demonstrated the advantage of the low-temperature method in reducing thermal shrinkage.

Objective. To evaluate the efficacy and safety of an intraoral electrostimulation device, consisting of stimulating electrodes, an electronic circuit, and a power source, in treating xerostomia. The device delivers electrostimulation through the oral mucosa to the lingual nerve in order to enhance the salivary reflex.Methods. The device was tested on a sample of patients with xerostomia due to Sjögren's syndrome and other sicca conditions in a 2-stage prospective, randomized, multicenter trial. Stage I was a double-blind, crossover stage designed to compare the effects of the electrically active device with the sham device, each used for 1 month, and stage II was a 3-month open-label stage designed to assess the long-term effects of the active device. Improvement in xerostomia severity from baseline was the primary outcome measure.Results. A total of 114 patients were randomized. In stage I, the active device performed better than the ClinicalTrials.gov identifier: NCT00509808. Drs.

No abstract

The relationship between the prosthodontic experience of dentists and satisfaction of complete denture wearers remains unknown. To investigate whether a prosthodontist's clinical experience affects treatment satisfaction of a complete denture wearer. From April 2004 to July 2006, we conducted a randomised controlled trial at two centres, including 74 edentulous patients; of these, 32 and 30 were randomly allocated to the ED or ID group, respectively. All the patients rated their satisfaction with dentures, including general satisfaction and satisfaction of chewing ability, speaking, cleaning, stability, retention, comfort and aesthetics. These satisfaction ratings were measured by a 100-mm visual analog scale (VAS). Perceived chewing ability to foods, divided into five grades, was measured using a questionnaire. The mastication index (MI) was calculated for each grade. General satisfaction and satisfaction of speaking, stability and retention were significantly higher in the ED than in the ID group (P = 0·049, 0·003, 0·019 and 0·041, respectively). No significant difference existed between the MI of the ED (71·3 ± 18·4) and ID group (64·1 ± 16·53). However, the perceived chewing ability of grade 5 food, whose texture was the hardest among all the grades, was significantly higher in the ED group than in the ID group. Within its limitations, this study showed that a clinician's prosthodontic experience affects a complete denture wearer's satisfaction ratings.