Single Maxillary Complete Denture Opposing Mandibular Natural Dentition

The fracture of complete dentures constitutes a challenge and remains an unresolved problem. A midline fracture of single maxillary complete denture base especially in patients who have retained their natural mandibular teeth is an inevitable problem. Several factors have been attributed for the midline fracture including flexural fatigue resulting from cyclic deformation and those which exacerbate the deformation of the base or alter its stress. The present case report deals with oral rehabilitation of completely edentulous maxillary arch by incorporating metal denture base in place of the conventional Poly Methyl Methacrylate material to improve the longevity of the prosthetic replacement, at the same time prevent resorption of the underlying residual maxillary ridge.

Single Complete Denture Boon OR Bane : A Case Report.

Eight to nine natural teeth in good condition in lower arch with a completely edentulous upper arch present a serious problem in prognosis of upper complete denture because of mid-line fractures. The personalities of patients in this situation can be seriously effected by what they consider is a hopeless state of their oral health. They feel that they cannot chew food properly, their mouths are uncomfortable and traumatized, the mandible can never seem to find a firmly defined terminal position and they believe that their physical appearance is marred beyond hope of remedy.

A study on the shear bond strength between Co-Cr denture base and relining materials / 대한치과보철학회지

PURPOSE: This study evaluated the bonding strength of direct relining resin to Co-Cr denture base material according to surface treatment and immersion time. MATERIALS AND METHODS: In this study, Co-Cr alloy was used in hexagon shape. Each specimen was cut in flat surface, and sandblasted with 110 microm Al2O3 for 1 minute. 54 specimens were divided into 3 groups; group A-control group, group B-applied with surface primer A, group C-applied with surface primer B. Self curing direct resin was used for this study. Each group was subdivided into another 3 groups according to the immersion time. After the wetting storage, shear bond strength of the specimens were measured with universal testing machine. The data were analyzed using two-way analysis of variance and Tukey post hoc method. RESULTS: In experiment of sandblasting specimens, surface roughness of the alloy was the highest after 1 minute sandblasting. In experiment of testing shear bond strength, bonding strength was lowered on group B, C, A. There were significant differences between 3 groups. According to period, Bonding strength was the highest on 0 week storage group, and the weakest on 2 week storage group. But there were no significant differences between 3 periods. According to group and period, bonding strength of all group were lowered according to immersion time but there were no significant differences on group B and group C, but there was significant difference according to immersion time on group A. CONCLUSION: It is useful to sandblast and adopt metal primers when relining Co-Cr metal base dentures in chair-side.

A comparative study on the dimensional change of the different denture bases / 대한치과보철학회지

STATEMENT OF PROBLEM: Acrylic resin is most commonly used for denture bases. However, acrylic resin has week points of volumetric shrinkage during polymerization that reduces denture fit. The expandability of POSS (Polyhedral Oligomeric Silsesquioxane) containing polymer could be expected to reduce the polymerization shrinkage of denture bases and would increase the adaptability of the denture to the tissue. PURPOSE: The purpose of this study was to compare the dimensional stability in the conventional acrylic resin base, POSS-containing acrylic resin base, and metal bases. MATERIALS AND METHODS: Thirty six maxillary edentulous casts and dentures of different base were fabricated. Tooth movement and tissue contour change of denture after processing (resin curing, deflasking, decasting and finishing without polishing) and immersion in artificial saliva at 37 degrees C for 1 week and 4 weeks were measured using digital measuring microscope and threedimensional laser scanner. RESULTS: The results were as follows: 1. The conventional resin group showed significant (p<0.01) dimensional change throughout the procedure (processing and immersion in artificial saliva). 2. After processing, the metal group and POSS resin group showed lower linear and 3-dimensional change than conventional resin group (p<0.01). 3. There was no statistically significant linear and 3-dimensional change after immersion for 1 week and 4 weeks in metal and POSS resin group. 4. In all groups, the midline and alveolar ridge crest area presented smaller 3-dimensional change compared with vestibule and posterior palatal seal area after processing and soaking in artificial saliva for 1 week and 4 weeks (p<0.01). CONCLUSION: In this study, a reinforced acrylic-based resin with POSS showed good dimensional stability.