Diurnal variation in palatal tissue thickness

A comparative analysis of the effect of three types of denture adhesives on the retention of maxillary denture bases: an in vivo study

There are many factors involved in the success of a good quality complete dentures, one of them is retention. There are some forcing situations where providing optimal retention may be a problem, in which use of denture adhesives is recommended. In the present study, primary and secondary impressions were made on 20 completely edentulous patients, master cast was fabricated. Master cast was duplicated; heat-cured denture base was fabricated. The retention test for control group, powder group, wafer group, paste group was done using a customized force sensor device. Readings was subjected to ANOVA followed by post hoc test. Results show that the retention force value of the paste group was the maximum, followed by powder group, wafer group and the least retention force value was observed with control group. Within the limitations of the study it can be concluded that the paste form of denture adhesive has the best retentive property compared to the powder and wafer.

Studies of changes in occlusion after the insertion of complete dentures. Part I

The present study aims to investigate changes in the occlusion of complete dentures after their insertion. A total of 85 edentulous patients were provided with new complete dentures. Their individual hinge axes were determined using mechanical axiography and the upper finished dentures were transferred by facebows to Dentatus articulators. The lower dentures were mounted according to an intraoral central bearing point (CBP) registration and equilibrated in terminal hinge position. An articulator specially modified for measurements in the condylar area was used. The differences between the positions of the condylar balls with CBP registration and those after equilibrating the occlusion were determined. On average, 19 days after insertion, 71 patients took part in a follow-up examination. As in the first session, the terminal hinge position was registered with the CBP method using the apex of the Gothic arch. Thus, the positions of the condylar balls immediately after the new registration could be compared with those in equilibrated intercuspation 3 weeks earlier. The differences were found to be 0.5 +/- 0.4 mm (0-2.9 mm) in the three axes (sagittal, coronal and horizontal). They are thought to result from settling into the denture bearing tissues and also from neuromuscular adjustment of the masticatory system. Compulsory remounting of complete dentures after insertion is therefore recommended.

Influence of circadian periodicity on reproducibility of centric relation records for edentulous patients

Complete dentures were made for 30 edentulous patients. The patients were divided into three groups and the dentures were remounted twice on the same day in a Vericheck instrument. The dentures for 10 patients were remounted twice in the morning (AM group), for 10 patients twice in the afternoon (PM group), and for 10 patients once in the morning and again in the afternoon (AM-PM group). Changes in position between the interocclusal records were measured on both the right and left horizontal X and Y axes and the sagittal Y and Z axes. No significant changes were noted when horizontal versus sagittal or right versus left positions were compared, but significant changes were noted between the AM versus AM-PM time groups, and between the PM versus AM-PM time groups.

The effect of relining on the accuracy and stability of maxillary complete dentures--an in vitro and in vivo study

A technique was developed for evaluating in vitro the accuracy or fit of experimental denture bases using a low-viscosity impression material for determining the space between the master die and the processed denture base. These measurements indicated that relining heat-cured maxillary denture bases with autopolymerizing acrylic resin improved their adaptation to the ridges. Interestingly, if no teeth were present in the heat-cured denture base, markedly less distortion occurred after processing. Limited clinical measurements on the stability of maxillary dentures in function showed no statistically significant change in stability after relining, but the trend was toward increased stability with the relined denture.